Remove CR at line ends.

diff --git a/crypto/bn/bn_modfs.c b/crypto/bn/bn_modfs.c
index 2697d54303aa23ac1385797426b78202fde14532..c6986fb2e770403dda3903e9410304cdc6a2cb8a 100644 (file)
--- a/crypto/bn/bn_modfs.c
+++ b/crypto/bn/bn_modfs.c
@@ -1,258 +1,258 @@
-/*\r
- *\r
- *     bn_modfs.c\r
- *\r
- *     Some Modular Arithmetic Functions.\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-\r
-#include <stdio.h>\r
-#include <stdlib.h>\r
-#include <assert.h>\r
-\r
-#include "bn_modfs.h"\r
-\r
-#define MAX_ROUNDS     10\r
-\r
-int BN_smod(BIGNUM *rem, BIGNUM *m, BIGNUM *d, BN_CTX *ctx)\r
-{\r
-       int r_sign;\r
-\r
-       assert(rem != NULL && m != NULL && d != NULL && ctx != NULL);\r
-\r
-       if (d->neg) return 0;\r
-       r_sign = m->neg;\r
-\r
-       if (r_sign) m->neg = 0;\r
-       if (!(BN_div(NULL,rem,m,d,ctx))) return 0;\r
-       if (r_sign) \r
-       {\r
-               m->neg = r_sign;\r
-               if (!BN_is_zero(rem))\r
-               {\r
-                       rem->neg = r_sign;\r
-                       BN_add(rem, rem, d);\r
-               }\r
-       }\r
-       return 1;\r
-}\r
-\r
-int BN_mod_sub(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx) \r
-{\r
-       assert(r != NULL && a != NULL && b != NULL && m != NULL && ctx != NULL);\r
-\r
-       if (!BN_sub(r, a, b)) return 0;\r
-       return BN_smod(r, r, m, ctx);\r
-\r
-}\r
-\r
-int BN_mod_add(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx) \r
-{\r
-       assert(r != NULL && a != NULL && b != NULL && m != NULL && ctx != NULL);\r
-\r
-       if (!BN_add(r, a, b)) return 0;\r
-       return BN_smod(r, r, m, ctx);\r
-\r
-}\r
-\r
-int BN_mod_sqr(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)\r
-{\r
-       assert(r != NULL && a != NULL && p != NULL && ctx != NULL);\r
-\r
-       if (!BN_sqr(r, a, ctx)) return 0;\r
-       return BN_div(NULL, r, r, p, ctx);\r
-}\r
-\r
-int BN_swap(BIGNUM *x, BIGNUM *y)\r
-{\r
-       BIGNUM *c;\r
-\r
-       assert(x != NULL && y != NULL);\r
-\r
-       if ((c = BN_dup(x)) == NULL) goto err;\r
-       if ((BN_copy(x, y)) == NULL) goto err;\r
-       if ((BN_copy(y, c)) == NULL) goto err;\r
-       BN_clear_free(c);\r
-       return 1;\r
-\r
-err:\r
-       if (c != NULL) BN_clear_free(c);\r
-       return 0;\r
-}\r
-\r
-\r
-int BN_legendre(BIGNUM *a, BIGNUM *p, BN_CTX *ctx) \r
-{\r
-       BIGNUM *x, *y, *y2;\r
-       BN_ULONG m;\r
-       int L;\r
-\r
-       assert(a != NULL && p != NULL && ctx != NULL);\r
-\r
-       x = ctx->bn[ctx->tos]; \r
-       y = ctx->bn[ctx->tos + 1]; \r
-       y2 = ctx->bn[ctx->tos + 2]; \r
-\r
-       ctx->tos += 3;\r
-\r
-       if (!BN_smod(x, a, p, ctx)) goto err;\r
-       if (BN_is_zero(x)) \r
-       {\r
-\r
-               ctx->tos -= 3;\r
-               return 0;\r
-       }\r
-\r
-       if (BN_copy(y, p) == NULL) goto err;\r
-       L = 1;\r
-\r
-       while (1)\r
-       {\r
-               if (!BN_rshift1(y2, y)) goto err;\r
-               if (BN_cmp(x, y2) > 0)\r
-               {\r
-                       if (!BN_sub(x, y, x)) goto err;\r
-                       if (BN_mod_word(y, 4) == 3)\r
-                               L = -L;                 \r
-               }\r
-               while (BN_mod_word(x, 4) == 0)\r
-                       BN_div_word(x, 4);\r
-               if (BN_mod_word(x, 2) == 0)\r
-               {\r
-                       BN_div_word(x, 2);\r
-                       m = BN_mod_word(y, 8);\r
-                       if (m == 3 || m == 5) L = -L;                   \r
-               }\r
-               if (BN_is_one(x)) \r
-               {\r
-                       ctx->tos -= 3;\r
-                       return L;\r
-               }\r
-               \r
-               if (BN_mod_word(x, 4) == 3 && BN_mod_word(y, 4) == 3) L = -L;\r
-               if (!BN_swap(x, y)) goto err;\r
-\r
-               if (!BN_smod(x, x, y, ctx)) goto err;\r
-\r
-       }\r
-\r
-\r
-err:\r
-       ctx->tos -= 3;\r
-       return -2;\r
-\r
-}\r
-\r
-int BN_mod_sqrt(BIGNUM *x, BIGNUM *a, BIGNUM *p, BN_CTX *ctx) \r
-/* x^2 = a (mod p) */\r
-{\r
-       int ret;\r
-       BIGNUM *n0, *n1, *r, *b, *m;\r
-       int max;\r
-\r
-       assert(x != NULL && a != NULL && p != NULL && ctx != NULL);\r
-       assert(BN_cmp(a, p) < 0);\r
-\r
-       ret = BN_legendre(a, p, ctx);\r
-       if (ret < 0 || ret > 1) return 0;\r
-       if (ret == 0)\r
-       {\r
-               if (!BN_zero(x)) return 0;\r
-               return 1;\r
-       }\r
-\r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       ctx->tos += 2;\r
-\r
-       if ((r = BN_new()) == NULL) goto err;\r
-       if ((b = BN_new()) == NULL) goto err;\r
-       if ((m = BN_new()) == NULL) goto err;\r
-\r
-\r
-       if (!BN_zero(n0)) goto err;\r
-       if (!BN_zero(n1)) goto err;\r
-       if (!BN_zero(r)) goto err;\r
-       if (!BN_zero(b)) goto err;\r
-       if (!BN_zero(m)) goto err;\r
-\r
-       max = 0;\r
-\r
-       do{\r
-               if (max++ > MAX_ROUNDS) goto err; /* if p is not prime could never stop*/\r
-               if (!BN_add_word(m, 1)) goto err;\r
-               ret = BN_legendre(m, p, ctx);\r
-               if (ret < -1 || ret > 1) goto err;\r
-\r
-       }while(ret != -1);\r
-\r
-       if (BN_copy(n1, p) == NULL) goto err;\r
-       if (!BN_sub_word(n1, 1)) goto err;\r
-\r
-       while (!BN_is_odd(n1))\r
-       {\r
-               if (!BN_add_word(r, 1)) goto err;\r
-               if (!BN_rshift1(n1, n1)) goto err;\r
-       }\r
-\r
-       if (!BN_mod_exp_simple(n0, m, n1, p, ctx)) goto err;\r
-\r
-       if (!BN_sub_word(n1, 1)) goto err;\r
-       if (!BN_rshift1(n1, n1)) goto err;\r
-       if (!BN_mod_exp_simple(x, a, n1, p, ctx)) goto err;\r
-\r
-       if (!BN_mod_sqr(b, x, p, ctx)) goto err;\r
-       if (!BN_mod_mul(b, b, a, p, ctx)) goto err;\r
-\r
-       if (!BN_mod_mul(x, x, a, p, ctx)) goto err;\r
-\r
-       while (!BN_is_one(b))\r
-       {\r
-               \r
-               if (!BN_one(m)) goto err;\r
-               if (!BN_mod_sqr(n1, b, p, ctx)) goto err;\r
-               while(!BN_is_one(n1))\r
-               {\r
-                       if (!BN_mod_mul(n1, n1, n1, p, ctx)) goto err;\r
-                       if (!BN_add_word(m, 1)) goto err;\r
-               }\r
-\r
-               if (!BN_sub(r, r, m)) goto err;\r
-               if (!BN_sub_word(r, 1)) goto err;\r
-               if (r->neg) goto err;\r
-\r
-               if (BN_copy(n1, n0) == NULL) goto err;\r
-               while(!BN_is_zero(r))\r
-               {\r
-                       if (!BN_mod_mul(n1, n1, n1, p, ctx)) goto err;\r
-                       if (!BN_sub_word(r, 1)) goto err;\r
-               }\r
-\r
-               if (!BN_mod_mul(n0, n1, n1, p, ctx)) goto err;\r
-               if (BN_copy(r, m) == NULL) goto err;\r
-               if (!BN_mod_mul(x, x, n1, p, ctx)) goto err;\r
-               if (!BN_mod_mul(b, b, n0, p, ctx)) goto err;\r
-       }\r
-\r
-\r
-#ifdef TEST\r
-       BN_mod_sqr(n0, x, p, ctx);\r
-       if (BN_cmp(n0, a)) goto err;\r
-#endif\r
-\r
-       if (r != NULL) BN_clear_free(r);\r
-       if (b != NULL) BN_clear_free(b);\r
-       if (m != NULL) BN_clear_free(m);\r
-       ctx->tos -= 2;\r
-       return 1;\r
-err:\r
-       if (r != NULL) BN_clear_free(r);\r
-       if (b != NULL) BN_clear_free(b);\r
-       if (m != NULL) BN_clear_free(m);\r
-       ctx->tos -= 2;\r
-       return 0;\r
-}\r
+/*
+ *
+ *     bn_modfs.c
+ *
+ *     Some Modular Arithmetic Functions.
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "bn_modfs.h"
+
+#define MAX_ROUNDS     10
+
+int BN_smod(BIGNUM *rem, BIGNUM *m, BIGNUM *d, BN_CTX *ctx)
+{
+       int r_sign;
+
+       assert(rem != NULL && m != NULL && d != NULL && ctx != NULL);
+
+       if (d->neg) return 0;
+       r_sign = m->neg;
+
+       if (r_sign) m->neg = 0;
+       if (!(BN_div(NULL,rem,m,d,ctx))) return 0;
+       if (r_sign) 
+       {
+               m->neg = r_sign;
+               if (!BN_is_zero(rem))
+               {
+                       rem->neg = r_sign;
+                       BN_add(rem, rem, d);
+               }
+       }
+       return 1;
+}
+
+int BN_mod_sub(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx) 
+{
+       assert(r != NULL && a != NULL && b != NULL && m != NULL && ctx != NULL);
+
+       if (!BN_sub(r, a, b)) return 0;
+       return BN_smod(r, r, m, ctx);
+
+}
+
+int BN_mod_add(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx) 
+{
+       assert(r != NULL && a != NULL && b != NULL && m != NULL && ctx != NULL);
+
+       if (!BN_add(r, a, b)) return 0;
+       return BN_smod(r, r, m, ctx);
+
+}
+
+int BN_mod_sqr(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)
+{
+       assert(r != NULL && a != NULL && p != NULL && ctx != NULL);
+
+       if (!BN_sqr(r, a, ctx)) return 0;
+       return BN_div(NULL, r, r, p, ctx);
+}
+
+int BN_swap(BIGNUM *x, BIGNUM *y)
+{
+       BIGNUM *c;
+
+       assert(x != NULL && y != NULL);
+
+       if ((c = BN_dup(x)) == NULL) goto err;
+       if ((BN_copy(x, y)) == NULL) goto err;
+       if ((BN_copy(y, c)) == NULL) goto err;
+       BN_clear_free(c);
+       return 1;
+
+err:
+       if (c != NULL) BN_clear_free(c);
+       return 0;
+}
+
+
+int BN_legendre(BIGNUM *a, BIGNUM *p, BN_CTX *ctx) 
+{
+       BIGNUM *x, *y, *y2;
+       BN_ULONG m;
+       int L;
+
+       assert(a != NULL && p != NULL && ctx != NULL);
+
+       x = ctx->bn[ctx->tos]; 
+       y = ctx->bn[ctx->tos + 1]; 
+       y2 = ctx->bn[ctx->tos + 2]; 
+
+       ctx->tos += 3;
+
+       if (!BN_smod(x, a, p, ctx)) goto err;
+       if (BN_is_zero(x)) 
+       {
+
+               ctx->tos -= 3;
+               return 0;
+       }
+
+       if (BN_copy(y, p) == NULL) goto err;
+       L = 1;
+
+       while (1)
+       {
+               if (!BN_rshift1(y2, y)) goto err;
+               if (BN_cmp(x, y2) > 0)
+               {
+                       if (!BN_sub(x, y, x)) goto err;
+                       if (BN_mod_word(y, 4) == 3)
+                               L = -L;                 
+               }
+               while (BN_mod_word(x, 4) == 0)
+                       BN_div_word(x, 4);
+               if (BN_mod_word(x, 2) == 0)
+               {
+                       BN_div_word(x, 2);
+                       m = BN_mod_word(y, 8);
+                       if (m == 3 || m == 5) L = -L;                   
+               }
+               if (BN_is_one(x)) 
+               {
+                       ctx->tos -= 3;
+                       return L;
+               }
+               
+               if (BN_mod_word(x, 4) == 3 && BN_mod_word(y, 4) == 3) L = -L;
+               if (!BN_swap(x, y)) goto err;
+
+               if (!BN_smod(x, x, y, ctx)) goto err;
+
+       }
+
+
+err:
+       ctx->tos -= 3;
+       return -2;
+
+}
+
+int BN_mod_sqrt(BIGNUM *x, BIGNUM *a, BIGNUM *p, BN_CTX *ctx) 
+/* x^2 = a (mod p) */
+{
+       int ret;
+       BIGNUM *n0, *n1, *r, *b, *m;
+       int max;
+
+       assert(x != NULL && a != NULL && p != NULL && ctx != NULL);
+       assert(BN_cmp(a, p) < 0);
+
+       ret = BN_legendre(a, p, ctx);
+       if (ret < 0 || ret > 1) return 0;
+       if (ret == 0)
+       {
+               if (!BN_zero(x)) return 0;
+               return 1;
+       }
+
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       ctx->tos += 2;
+
+       if ((r = BN_new()) == NULL) goto err;
+       if ((b = BN_new()) == NULL) goto err;
+       if ((m = BN_new()) == NULL) goto err;
+
+
+       if (!BN_zero(n0)) goto err;
+       if (!BN_zero(n1)) goto err;
+       if (!BN_zero(r)) goto err;
+       if (!BN_zero(b)) goto err;
+       if (!BN_zero(m)) goto err;
+
+       max = 0;
+
+       do{
+               if (max++ > MAX_ROUNDS) goto err; /* if p is not prime could never stop*/
+               if (!BN_add_word(m, 1)) goto err;
+               ret = BN_legendre(m, p, ctx);
+               if (ret < -1 || ret > 1) goto err;
+
+       }while(ret != -1);
+
+       if (BN_copy(n1, p) == NULL) goto err;
+       if (!BN_sub_word(n1, 1)) goto err;
+
+       while (!BN_is_odd(n1))
+       {
+               if (!BN_add_word(r, 1)) goto err;
+               if (!BN_rshift1(n1, n1)) goto err;
+       }
+
+       if (!BN_mod_exp_simple(n0, m, n1, p, ctx)) goto err;
+
+       if (!BN_sub_word(n1, 1)) goto err;
+       if (!BN_rshift1(n1, n1)) goto err;
+       if (!BN_mod_exp_simple(x, a, n1, p, ctx)) goto err;
+
+       if (!BN_mod_sqr(b, x, p, ctx)) goto err;
+       if (!BN_mod_mul(b, b, a, p, ctx)) goto err;
+
+       if (!BN_mod_mul(x, x, a, p, ctx)) goto err;
+
+       while (!BN_is_one(b))
+       {
+               
+               if (!BN_one(m)) goto err;
+               if (!BN_mod_sqr(n1, b, p, ctx)) goto err;
+               while(!BN_is_one(n1))
+               {
+                       if (!BN_mod_mul(n1, n1, n1, p, ctx)) goto err;
+                       if (!BN_add_word(m, 1)) goto err;
+               }
+
+               if (!BN_sub(r, r, m)) goto err;
+               if (!BN_sub_word(r, 1)) goto err;
+               if (r->neg) goto err;
+
+               if (BN_copy(n1, n0) == NULL) goto err;
+               while(!BN_is_zero(r))
+               {
+                       if (!BN_mod_mul(n1, n1, n1, p, ctx)) goto err;
+                       if (!BN_sub_word(r, 1)) goto err;
+               }
+
+               if (!BN_mod_mul(n0, n1, n1, p, ctx)) goto err;
+               if (BN_copy(r, m) == NULL) goto err;
+               if (!BN_mod_mul(x, x, n1, p, ctx)) goto err;
+               if (!BN_mod_mul(b, b, n0, p, ctx)) goto err;
+       }
+
+
+#ifdef TEST
+       BN_mod_sqr(n0, x, p, ctx);
+       if (BN_cmp(n0, a)) goto err;
+#endif
+
+       if (r != NULL) BN_clear_free(r);
+       if (b != NULL) BN_clear_free(b);
+       if (m != NULL) BN_clear_free(m);
+       ctx->tos -= 2;
+       return 1;
+err:
+       if (r != NULL) BN_clear_free(r);
+       if (b != NULL) BN_clear_free(b);
+       if (m != NULL) BN_clear_free(m);
+       ctx->tos -= 2;
+       return 0;
+}

diff --git a/crypto/bn/bn_modfs.h b/crypto/bn/bn_modfs.h
index b7ae4964d87b4bdbf708b4432013475f0c501d75..c596ca3973332e495832cb1c4d09f9bb81da7a69 100644 (file)
--- a/crypto/bn/bn_modfs.h
+++ b/crypto/bn/bn_modfs.h
@@ -1,32 +1,32 @@
-/*\r
- *\r
- *     bn_modfs.h\r
- *\r
- *     Some Modular Arithmetic Functions.\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-#ifndef HEADER_BN_MODFS_H\r
-#define HEADER_BN_MODFS_H\r
-\r
-\r
-#include "bn.h"\r
-\r
-#ifdef BN_is_zero\r
-#undef BN_is_zero\r
-#define BN_is_zero(a)  (((a)->top == 0) || (((a)->top == 1) && ((a)->d[0] == (BN_ULONG)0)))\r
-#endif /*BN_is_zero(a)*/\r
-\r
-\r
-int BN_smod(BIGNUM *rem, BIGNUM *m, BIGNUM *d, BN_CTX *ctx);\r
-int BN_mod_sub(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx);\r
-int BN_mod_add(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx); \r
-int BN_mod_sqr(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx);\r
-int BN_swap(BIGNUM *x, BIGNUM *y);\r
-int BN_legendre(BIGNUM *a, BIGNUM *p, BN_CTX *ctx);\r
-int BN_mod_sqrt(BIGNUM *x, BIGNUM *a, BIGNUM *p, BN_CTX *ctx);\r
-\r
+/*
+ *
+ *     bn_modfs.h
+ *
+ *     Some Modular Arithmetic Functions.
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+#ifndef HEADER_BN_MODFS_H
+#define HEADER_BN_MODFS_H
+
+
+#include "bn.h"
+
+#ifdef BN_is_zero
+#undef BN_is_zero
+#define BN_is_zero(a)  (((a)->top == 0) || (((a)->top == 1) && ((a)->d[0] == (BN_ULONG)0)))
+#endif /*BN_is_zero(a)*/
+
+
+int BN_smod(BIGNUM *rem, BIGNUM *m, BIGNUM *d, BN_CTX *ctx);
+int BN_mod_sub(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx);
+int BN_mod_add(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx); 
+int BN_mod_sqr(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx);
+int BN_swap(BIGNUM *x, BIGNUM *y);
+int BN_legendre(BIGNUM *a, BIGNUM *p, BN_CTX *ctx);
+int BN_mod_sqrt(BIGNUM *x, BIGNUM *a, BIGNUM *p, BN_CTX *ctx);
+
 #endif
\ No newline at end of file

diff --git a/crypto/bn/bn_mont2.c b/crypto/bn/bn_mont2.c
index 9f6222fb13204caf541411da0023ae40616f7648..871282400c65e89995b1a404fb2b50c2c3e945be 100644 (file)
--- a/crypto/bn/bn_mont2.c
+++ b/crypto/bn/bn_mont2.c
@@ -1,374 +1,374 @@
-/*\r
- *\r
- *     bn_mont2.c\r
- *\r
- *     Montgomery Modular Arithmetic Functions.\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-\r
-#include <stdio.h>\r
-#include <stdlib.h>\r
-#include <assert.h>\r
-\r
-#include "bn.h"\r
-#include "bn_modfs.h"\r
-#include "bn_mont2.h"\r
-\r
-#define BN_mask_word(x, m) ((x->d[0]) & (m))\r
-\r
-BN_MONTGOMERY *BN_mont_new()\r
-{\r
-       BN_MONTGOMERY *ret;\r
-\r
-       ret=(BN_MONTGOMERY *)malloc(sizeof(BN_MONTGOMERY));\r
-\r
-       if (ret == NULL) return NULL;\r
-\r
-       if ((ret->p = BN_new()) == NULL)\r
-       {\r
-               free(ret);\r
-               return NULL;\r
-       }\r
-\r
-       return ret;\r
-}\r
-\r
-\r
-void BN_mont_clear_free(BN_MONTGOMERY *mont)\r
-{\r
-       if (mont == NULL) return;\r
-\r
-       if (mont->p != NULL) BN_clear_free(mont->p);\r
-\r
-       mont->p_num_bytes = 0;\r
-       mont->R_num_bits = 0;\r
-       mont->p_inv_b_neg = 0;\r
-}\r
-\r
-int BN_to_mont(BIGNUM *x, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-       assert(x != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (!BN_lshift(x, x, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(x, x, mont->p, ctx)) return 0;\r
-\r
-       return 1;\r
-}\r
-\r
-\r
-static BN_ULONG BN_mont_inv(BIGNUM *a, int e, BN_CTX *ctx)\r
-/* y = a^{-1} (mod 2^e) for an odd number a */\r
-{\r
-       BN_ULONG y, exp, mask;\r
-       BIGNUM *x, *xy, *x_sh;\r
-       int i;\r
-\r
-       assert(a != NULL && ctx != NULL);\r
-       assert(e <= BN_BITS2);\r
-       assert(BN_is_odd(a));\r
-       assert(!BN_is_zero(a) && !a->neg);\r
-\r
-\r
-       y = 1;\r
-       exp = 2;\r
-       mask = 3;\r
-       if((x = BN_dup(a)) == NULL) return 0;\r
-       if(!BN_mask_bits(x, e)) return 0;\r
-\r
-       xy = ctx->bn[ctx->tos]; \r
-       x_sh = ctx->bn[ctx->tos + 1]; \r
-       ctx->tos += 2;\r
-\r
-       if (BN_copy(xy, x) == NULL) goto err;\r
-       if (!BN_lshift1(x_sh, x)) goto err;\r
-\r
-\r
-       for (i = 2; i <= e; i++)\r
-       {\r
-               if (exp < BN_mask_word(xy, mask))\r
-               {\r
-                       y = y + exp;\r
-                       if (!BN_add(xy, xy, x_sh)) goto err;\r
-               }\r
-\r
-               exp <<= 1;\r
-               if (!BN_lshift1(x_sh, x_sh)) goto err;\r
-               mask <<= 1;\r
-               mask++;\r
-       }\r
-\r
-\r
-#ifdef TEST\r
-       if (xy->d[0] != 1) goto err;\r
-#endif\r
-\r
-       if (x != NULL) BN_clear_free(x);\r
-       ctx->tos -= 2;\r
-       return y;\r
-\r
-\r
-err:\r
-       if (x != NULL) BN_clear_free(x);\r
-       ctx->tos -= 2;\r
-       return 0;\r
-\r
-}\r
-\r
-int BN_mont_set(BIGNUM *p, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-       assert(p != NULL && ctx != NULL);\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(!BN_is_zero(p) && !p->neg);\r
-\r
-\r
-       mont->p_num_bytes = p->top;\r
-       mont->R_num_bits = (mont->p_num_bytes) * BN_BITS2;\r
-\r
-       if (BN_copy(mont->p, p) == NULL);\r
-       \r
-       mont->p_inv_b_neg =  BN_mont_inv(p, BN_BITS2, ctx);\r
-       mont->p_inv_b_neg = 0 - mont->p_inv_b_neg;\r
-\r
-       return 1;\r
-}\r
-\r
-static int BN_cpy_mul_word(BIGNUM *ret, BIGNUM *a, BN_ULONG w)\r
-/* ret = a * w */\r
-{\r
-       if (BN_copy(ret, a) == NULL) return 0;\r
-\r
-       if (!BN_mul_word(ret, w)) return 0;\r
-\r
-       return 1;\r
-}\r
-\r
-\r
-int BN_mont_red(BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-/* yR^{-1} (mod p) */\r
-{\r
-       int i;\r
-       BIGNUM *up, *p;\r
-       BN_ULONG u;\r
-\r
-       assert(y != NULL && mont != NULL && ctx != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(BN_cmp(y, mont->p) < 0);\r
-       assert(!y->neg);\r
-\r
-\r
-       if (BN_is_zero(y)) return 1;\r
-\r
-       p = mont->p;\r
-       up = ctx->bn[ctx->tos]; \r
-       ctx->tos += 1;\r
-\r
-\r
-       for (i = 0; i < mont->p_num_bytes; i++)\r
-       {\r
-               u = (y->d[0]) * mont->p_inv_b_neg;                      /* u = y_0 * p' */\r
-\r
-               if (!BN_cpy_mul_word(up, p, u)) goto err;       /* up = u * p */\r
-\r
-               if (!BN_add(y, y, up)) goto err;                        \r
-#ifdef TEST\r
-               if (y->d[0]) goto err;\r
-#endif\r
-               if (!BN_rshift(y, y, BN_BITS2)) goto err;       /* y = (y + up)/b */\r
-       }\r
-\r
-\r
-       if (BN_cmp(y, mont->p) >= 0) \r
-       {\r
-               if (!BN_sub(y, y, mont->p)) goto err;\r
-       }\r
-\r
-       ctx->tos -= 1;\r
-       return 1;\r
-\r
-err:\r
-       ctx->tos -= 1;\r
-       return 0;\r
-\r
-}\r
-\r
-\r
-int BN_mont_mod_mul(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-/* r = x * y mod p */\r
-/* r != x && r! = y !!! */\r
-{\r
-       BIGNUM *xiy, *up;\r
-       BN_ULONG u;\r
-       int i;\r
-       \r
-\r
-       assert(r != x && r != y);\r
-       assert(r != NULL && x != NULL  && y != NULL && mont != NULL && ctx != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(BN_cmp(x, mont->p) < 0);\r
-       assert(BN_cmp(y, mont->p) < 0);\r
-       assert(!x->neg);\r
-       assert(!y->neg);\r
-\r
-       if (BN_is_zero(x) || BN_is_zero(y))\r
-       {\r
-               if (!BN_zero(r)) return 0;\r
-               return 1;\r
-       }\r
-\r
-\r
-\r
-       xiy = ctx->bn[ctx->tos]; \r
-       up = ctx->bn[ctx->tos + 1]; \r
-       ctx->tos += 2;\r
-\r
-       if (!BN_zero(r)) goto err;\r
-\r
-       for (i = 0; i < x->top; i++)\r
-       {\r
-               u = (r->d[0] + x->d[i] * y->d[0]) * mont->p_inv_b_neg;\r
-\r
-               if (!BN_cpy_mul_word(xiy, y, x->d[i])) goto err;\r
-               if (!BN_cpy_mul_word(up, mont->p, u)) goto err;\r
-\r
-               if (!BN_add(r, r, xiy)) goto err;\r
-               if (!BN_add(r, r, up)) goto err;\r
-\r
-#ifdef TEST\r
-               if (r->d[0]) goto err;\r
-#endif\r
-               if (!BN_rshift(r, r, BN_BITS2)) goto err; \r
-       }\r
-\r
-       for (i = x->top; i < mont->p_num_bytes; i++)\r
-       {\r
-               u = (r->d[0]) * mont->p_inv_b_neg;\r
-\r
-               if (!BN_cpy_mul_word(up, mont->p, u)) goto err;\r
-\r
-               if (!BN_add(r, r, up)) goto err;\r
-\r
-#ifdef TEST\r
-               if (r->d[0]) goto err;\r
-#endif\r
-               if (!BN_rshift(r, r, BN_BITS2)) goto err; \r
-       }\r
-\r
-\r
-       if (BN_cmp(r, mont->p) >= 0) \r
-       {\r
-               if (!BN_sub(r, r, mont->p)) goto err;\r
-       }\r
-\r
-\r
-       ctx->tos -= 2;\r
-       return 1;\r
-\r
-err:\r
-       ctx->tos -= 2;\r
-       return 0;\r
-}\r
-\r
-int BN_mont_mod_add(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont)\r
-{\r
-       assert(r != NULL && x != NULL  && y != NULL && mont != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(BN_cmp(x, mont->p) < 0);\r
-       assert(BN_cmp(y, mont->p) < 0);\r
-       assert(!x->neg);\r
-       assert(!y->neg);\r
-\r
-       if (!BN_add(r, x, y)) return 0;\r
-       if (BN_cmp(r, mont->p) >= 0) \r
-       {\r
-               if (!BN_sub(r, r, mont->p)) return 0;\r
-       }\r
-\r
-       return 1;\r
-}\r
-\r
-\r
-int BN_mont_mod_sub(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont)\r
-{\r
-       assert(r != NULL && x != NULL  && y != NULL && mont != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(BN_cmp(x, mont->p) < 0);\r
-       assert(BN_cmp(y, mont->p) < 0);\r
-       assert(!x->neg);\r
-       assert(!y->neg);\r
-\r
-       if (!BN_sub(r, x, y)) return 0;\r
-       if (r->neg) \r
-       {\r
-               if (!BN_add(r, r, mont->p)) return 0;\r
-       }\r
-\r
-       return 1;\r
-}\r
-\r
-int BN_mont_mod_lshift1(BIGNUM *r, BIGNUM *x, BN_MONTGOMERY *mont)\r
-{\r
-       assert(r != NULL && x != NULL && mont != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(BN_cmp(x, mont->p) < 0);\r
-       assert(!x->neg);\r
-\r
-       if (!BN_lshift1(r, x)) return 0;\r
-\r
-       if (BN_cmp(r, mont->p) >= 0) \r
-       {\r
-               if (!BN_sub(r, r, mont->p)) return 0;\r
-       }\r
-\r
-       return 1;\r
-}\r
-\r
-int BN_mont_mod_lshift(BIGNUM *r, BIGNUM *x, int n, BN_MONTGOMERY *mont)\r
-{\r
-       int sh_nb;\r
-\r
-       assert(r != NULL && x != NULL && mont != NULL);\r
-       assert(mont->p != NULL);\r
-       assert(BN_cmp(x, mont->p) < 0);\r
-       assert(!x->neg);\r
-       assert(n > 0);\r
-\r
-       if (r != x)\r
-       {\r
-               if (BN_copy(r, x) == NULL) return 0;\r
-       }\r
-\r
-       while (n)\r
-       {\r
-               sh_nb = BN_num_bits(mont->p) - BN_num_bits(r);\r
-               if (sh_nb > n) sh_nb = n;\r
-\r
-               if (sh_nb)\r
-               {\r
-                       if(!BN_lshift(r, r, sh_nb)) return 0;\r
-               }\r
-               else \r
-               {\r
-                       sh_nb = 1;\r
-                       if (!BN_lshift1(r, r)) return 0;\r
-               }\r
-\r
-               if (BN_cmp(r, mont->p) >= 0) \r
-               {\r
-                       if (!BN_sub(r, r, mont->p)) return 0;\r
-               }\r
-\r
-               n -= sh_nb;\r
-       }\r
-\r
-       return 1;\r
-}\r
+/*
+ *
+ *     bn_mont2.c
+ *
+ *     Montgomery Modular Arithmetic Functions.
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "bn.h"
+#include "bn_modfs.h"
+#include "bn_mont2.h"
+
+#define BN_mask_word(x, m) ((x->d[0]) & (m))
+
+BN_MONTGOMERY *BN_mont_new()
+{
+       BN_MONTGOMERY *ret;
+
+       ret=(BN_MONTGOMERY *)malloc(sizeof(BN_MONTGOMERY));
+
+       if (ret == NULL) return NULL;
+
+       if ((ret->p = BN_new()) == NULL)
+       {
+               free(ret);
+               return NULL;
+       }
+
+       return ret;
+}
+
+
+void BN_mont_clear_free(BN_MONTGOMERY *mont)
+{
+       if (mont == NULL) return;
+
+       if (mont->p != NULL) BN_clear_free(mont->p);
+
+       mont->p_num_bytes = 0;
+       mont->R_num_bits = 0;
+       mont->p_inv_b_neg = 0;
+}
+
+int BN_to_mont(BIGNUM *x, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+       assert(x != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       assert(ctx != NULL);
+
+       if (!BN_lshift(x, x, mont->R_num_bits)) return 0;
+       if (!BN_mod(x, x, mont->p, ctx)) return 0;
+
+       return 1;
+}
+
+
+static BN_ULONG BN_mont_inv(BIGNUM *a, int e, BN_CTX *ctx)
+/* y = a^{-1} (mod 2^e) for an odd number a */
+{
+       BN_ULONG y, exp, mask;
+       BIGNUM *x, *xy, *x_sh;
+       int i;
+
+       assert(a != NULL && ctx != NULL);
+       assert(e <= BN_BITS2);
+       assert(BN_is_odd(a));
+       assert(!BN_is_zero(a) && !a->neg);
+
+
+       y = 1;
+       exp = 2;
+       mask = 3;
+       if((x = BN_dup(a)) == NULL) return 0;
+       if(!BN_mask_bits(x, e)) return 0;
+
+       xy = ctx->bn[ctx->tos]; 
+       x_sh = ctx->bn[ctx->tos + 1]; 
+       ctx->tos += 2;
+
+       if (BN_copy(xy, x) == NULL) goto err;
+       if (!BN_lshift1(x_sh, x)) goto err;
+
+
+       for (i = 2; i <= e; i++)
+       {
+               if (exp < BN_mask_word(xy, mask))
+               {
+                       y = y + exp;
+                       if (!BN_add(xy, xy, x_sh)) goto err;
+               }
+
+               exp <<= 1;
+               if (!BN_lshift1(x_sh, x_sh)) goto err;
+               mask <<= 1;
+               mask++;
+       }
+
+
+#ifdef TEST
+       if (xy->d[0] != 1) goto err;
+#endif
+
+       if (x != NULL) BN_clear_free(x);
+       ctx->tos -= 2;
+       return y;
+
+
+err:
+       if (x != NULL) BN_clear_free(x);
+       ctx->tos -= 2;
+       return 0;
+
+}
+
+int BN_mont_set(BIGNUM *p, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+       assert(p != NULL && ctx != NULL);
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+       assert(!BN_is_zero(p) && !p->neg);
+
+
+       mont->p_num_bytes = p->top;
+       mont->R_num_bits = (mont->p_num_bytes) * BN_BITS2;
+
+       if (BN_copy(mont->p, p) == NULL);
+       
+       mont->p_inv_b_neg =  BN_mont_inv(p, BN_BITS2, ctx);
+       mont->p_inv_b_neg = 0 - mont->p_inv_b_neg;
+
+       return 1;
+}
+
+static int BN_cpy_mul_word(BIGNUM *ret, BIGNUM *a, BN_ULONG w)
+/* ret = a * w */
+{
+       if (BN_copy(ret, a) == NULL) return 0;
+
+       if (!BN_mul_word(ret, w)) return 0;
+
+       return 1;
+}
+
+
+int BN_mont_red(BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx)
+/* yR^{-1} (mod p) */
+{
+       int i;
+       BIGNUM *up, *p;
+       BN_ULONG u;
+
+       assert(y != NULL && mont != NULL && ctx != NULL);
+       assert(mont->p != NULL);
+       assert(BN_cmp(y, mont->p) < 0);
+       assert(!y->neg);
+
+
+       if (BN_is_zero(y)) return 1;
+
+       p = mont->p;
+       up = ctx->bn[ctx->tos]; 
+       ctx->tos += 1;
+
+
+       for (i = 0; i < mont->p_num_bytes; i++)
+       {
+               u = (y->d[0]) * mont->p_inv_b_neg;                      /* u = y_0 * p' */
+
+               if (!BN_cpy_mul_word(up, p, u)) goto err;       /* up = u * p */
+
+               if (!BN_add(y, y, up)) goto err;                        
+#ifdef TEST
+               if (y->d[0]) goto err;
+#endif
+               if (!BN_rshift(y, y, BN_BITS2)) goto err;       /* y = (y + up)/b */
+       }
+
+
+       if (BN_cmp(y, mont->p) >= 0) 
+       {
+               if (!BN_sub(y, y, mont->p)) goto err;
+       }
+
+       ctx->tos -= 1;
+       return 1;
+
+err:
+       ctx->tos -= 1;
+       return 0;
+
+}
+
+
+int BN_mont_mod_mul(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx)
+/* r = x * y mod p */
+/* r != x && r! = y !!! */
+{
+       BIGNUM *xiy, *up;
+       BN_ULONG u;
+       int i;
+       
+
+       assert(r != x && r != y);
+       assert(r != NULL && x != NULL  && y != NULL && mont != NULL && ctx != NULL);
+       assert(mont->p != NULL);
+       assert(BN_cmp(x, mont->p) < 0);
+       assert(BN_cmp(y, mont->p) < 0);
+       assert(!x->neg);
+       assert(!y->neg);
+
+       if (BN_is_zero(x) || BN_is_zero(y))
+       {
+               if (!BN_zero(r)) return 0;
+               return 1;
+       }
+
+
+
+       xiy = ctx->bn[ctx->tos]; 
+       up = ctx->bn[ctx->tos + 1]; 
+       ctx->tos += 2;
+
+       if (!BN_zero(r)) goto err;
+
+       for (i = 0; i < x->top; i++)
+       {
+               u = (r->d[0] + x->d[i] * y->d[0]) * mont->p_inv_b_neg;
+
+               if (!BN_cpy_mul_word(xiy, y, x->d[i])) goto err;
+               if (!BN_cpy_mul_word(up, mont->p, u)) goto err;
+
+               if (!BN_add(r, r, xiy)) goto err;
+               if (!BN_add(r, r, up)) goto err;
+
+#ifdef TEST
+               if (r->d[0]) goto err;
+#endif
+               if (!BN_rshift(r, r, BN_BITS2)) goto err; 
+       }
+
+       for (i = x->top; i < mont->p_num_bytes; i++)
+       {
+               u = (r->d[0]) * mont->p_inv_b_neg;
+
+               if (!BN_cpy_mul_word(up, mont->p, u)) goto err;
+
+               if (!BN_add(r, r, up)) goto err;
+
+#ifdef TEST
+               if (r->d[0]) goto err;
+#endif
+               if (!BN_rshift(r, r, BN_BITS2)) goto err; 
+       }
+
+
+       if (BN_cmp(r, mont->p) >= 0) 
+       {
+               if (!BN_sub(r, r, mont->p)) goto err;
+       }
+
+
+       ctx->tos -= 2;
+       return 1;
+
+err:
+       ctx->tos -= 2;
+       return 0;
+}
+
+int BN_mont_mod_add(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont)
+{
+       assert(r != NULL && x != NULL  && y != NULL && mont != NULL);
+       assert(mont->p != NULL);
+       assert(BN_cmp(x, mont->p) < 0);
+       assert(BN_cmp(y, mont->p) < 0);
+       assert(!x->neg);
+       assert(!y->neg);
+
+       if (!BN_add(r, x, y)) return 0;
+       if (BN_cmp(r, mont->p) >= 0) 
+       {
+               if (!BN_sub(r, r, mont->p)) return 0;
+       }
+
+       return 1;
+}
+
+
+int BN_mont_mod_sub(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont)
+{
+       assert(r != NULL && x != NULL  && y != NULL && mont != NULL);
+       assert(mont->p != NULL);
+       assert(BN_cmp(x, mont->p) < 0);
+       assert(BN_cmp(y, mont->p) < 0);
+       assert(!x->neg);
+       assert(!y->neg);
+
+       if (!BN_sub(r, x, y)) return 0;
+       if (r->neg) 
+       {
+               if (!BN_add(r, r, mont->p)) return 0;
+       }
+
+       return 1;
+}
+
+int BN_mont_mod_lshift1(BIGNUM *r, BIGNUM *x, BN_MONTGOMERY *mont)
+{
+       assert(r != NULL && x != NULL && mont != NULL);
+       assert(mont->p != NULL);
+       assert(BN_cmp(x, mont->p) < 0);
+       assert(!x->neg);
+
+       if (!BN_lshift1(r, x)) return 0;
+
+       if (BN_cmp(r, mont->p) >= 0) 
+       {
+               if (!BN_sub(r, r, mont->p)) return 0;
+       }
+
+       return 1;
+}
+
+int BN_mont_mod_lshift(BIGNUM *r, BIGNUM *x, int n, BN_MONTGOMERY *mont)
+{
+       int sh_nb;
+
+       assert(r != NULL && x != NULL && mont != NULL);
+       assert(mont->p != NULL);
+       assert(BN_cmp(x, mont->p) < 0);
+       assert(!x->neg);
+       assert(n > 0);
+
+       if (r != x)
+       {
+               if (BN_copy(r, x) == NULL) return 0;
+       }
+
+       while (n)
+       {
+               sh_nb = BN_num_bits(mont->p) - BN_num_bits(r);
+               if (sh_nb > n) sh_nb = n;
+
+               if (sh_nb)
+               {
+                       if(!BN_lshift(r, r, sh_nb)) return 0;
+               }
+               else 
+               {
+                       sh_nb = 1;
+                       if (!BN_lshift1(r, r)) return 0;
+               }
+
+               if (BN_cmp(r, mont->p) >= 0) 
+               {
+                       if (!BN_sub(r, r, mont->p)) return 0;
+               }
+
+               n -= sh_nb;
+       }
+
+       return 1;
+}

diff --git a/crypto/bn/bn_mont2.h b/crypto/bn/bn_mont2.h
index 1bce6d71f1d27910b8df66001d08fd85f08a1b52..e33c65401e62d8aec6f909a7e419d7c50e96b70d 100644 (file)
--- a/crypto/bn/bn_mont2.h
+++ b/crypto/bn/bn_mont2.h
@@ -1,41 +1,41 @@
-/*\r
- *\r
- *     bn_mont2.h\r
- *\r
- *     Montgomery Modular Arithmetic Functions.\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-#ifndef HEADER_MONT2_H\r
-#define HEADER_MONT2_H\r
-\r
-#define MONTGOMERY\r
-\r
-#include "bn.h"\r
-\r
-typedef struct bn_mont_st{\r
-       int R_num_bits;\r
-       int p_num_bytes;\r
-       BIGNUM *p;\r
-       BN_ULONG p_inv_b_neg;   /* p' = p^{-1} mod b; b = 2^BN_BITS */\r
-} BN_MONTGOMERY;\r
-\r
-#define BN_from_mont(x, mont, ctx) (BN_mont_red((x), (mont), (ctx)))\r
-\r
-\r
-BN_MONTGOMERY *BN_mont_new();\r
-int BN_to_mont(BIGNUM *x, BN_MONTGOMERY *mont, BN_CTX *ctx); \r
-void BN_mont_clear_free(BN_MONTGOMERY *mont);\r
-int BN_mont_set(BIGNUM *p, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int BN_mont_red(BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-BN_ULONG BN_mont_inv(BIGNUM *x, int e, BN_CTX *ctx);\r
-int BN_mont_mod_mul(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int BN_mont_mod_add(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont);\r
-int BN_mont_mod_sub(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont);\r
-int BN_mont_mod_lshift1(BIGNUM *r, BIGNUM *x, BN_MONTGOMERY *mont);\r
-int BN_mont_mod_lshift(BIGNUM *r, BIGNUM *x, int n, BN_MONTGOMERY *mont);\r
-\r
+/*
+ *
+ *     bn_mont2.h
+ *
+ *     Montgomery Modular Arithmetic Functions.
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+#ifndef HEADER_MONT2_H
+#define HEADER_MONT2_H
+
+#define MONTGOMERY
+
+#include "bn.h"
+
+typedef struct bn_mont_st{
+       int R_num_bits;
+       int p_num_bytes;
+       BIGNUM *p;
+       BN_ULONG p_inv_b_neg;   /* p' = p^{-1} mod b; b = 2^BN_BITS */
+} BN_MONTGOMERY;
+
+#define BN_from_mont(x, mont, ctx) (BN_mont_red((x), (mont), (ctx)))
+
+
+BN_MONTGOMERY *BN_mont_new();
+int BN_to_mont(BIGNUM *x, BN_MONTGOMERY *mont, BN_CTX *ctx); 
+void BN_mont_clear_free(BN_MONTGOMERY *mont);
+int BN_mont_set(BIGNUM *p, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int BN_mont_red(BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx);
+BN_ULONG BN_mont_inv(BIGNUM *x, int e, BN_CTX *ctx);
+int BN_mont_mod_mul(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int BN_mont_mod_add(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont);
+int BN_mont_mod_sub(BIGNUM *r, BIGNUM *x, BIGNUM *y, BN_MONTGOMERY *mont);
+int BN_mont_mod_lshift1(BIGNUM *r, BIGNUM *x, BN_MONTGOMERY *mont);
+int BN_mont_mod_lshift(BIGNUM *r, BIGNUM *x, int n, BN_MONTGOMERY *mont);
+
 #endif
\ No newline at end of file

diff --git a/crypto/ec/ec.c b/crypto/ec/ec.c
index bc689e74f288cea62d5e6adcf8e014baab00fb69..aec4c4e062588440e3027609734aa99d03d0578b 100644 (file)
--- a/crypto/ec/ec.c
+++ b/crypto/ec/ec.c
@@ -1,121 +1,121 @@
-/*\r
- *\r
- *     ec.c\r
- *\r
- *     Elliptic Curve Arithmetic Functions\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-\r
-#include <stdio.h>\r
-#include <stdlib.h>\r
-#include <assert.h>\r
-\r
-#include "ec.h"\r
-#include "bn_modfs.h"\r
-\r
-\r
-\r
-EC *EC_new()\r
-{\r
-       EC *ret;\r
-\r
-       ret=(EC *)malloc(sizeof(EC));\r
-       if (ret == NULL) return NULL;\r
-       ret->A = BN_new();\r
-       ret->B = BN_new();\r
-       ret->p = BN_new();\r
-       ret->h = BN_new();\r
-       ret->is_in_mont = 0;\r
-\r
-       if (ret->A == NULL || ret->B == NULL || ret->p == NULL || ret->h == NULL)\r
-       {\r
-               if (ret->A != NULL) BN_free(ret->A);\r
-               if (ret->B != NULL) BN_free(ret->B);\r
-               if (ret->p != NULL) BN_free(ret->p);\r
-               if (ret->h != NULL) BN_free(ret->h);\r
-               free(ret);\r
-               return(NULL);\r
-       }\r
-       return(ret);\r
-}\r
-\r
-\r
-void EC_clear_free(EC *E)\r
-{\r
-       if (E == NULL) return;\r
-\r
-       if (E->A != NULL) BN_clear_free(E->A);\r
-       if (E->B != NULL) BN_clear_free(E->B);\r
-       if (E->p != NULL) BN_clear_free(E->p);\r
-       if (E->h != NULL) BN_clear_free(E->h);\r
-       E->is_in_mont = 0;\r
-       free(E);\r
-}\r
-\r
-\r
-#ifdef MONTGOMERY\r
-int EC_to_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (E->is_in_mont) return 1;\r
-\r
-       if (!BN_lshift(E->A, E->A, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(E->A, E->A, mont->p, ctx)) return 0;\r
-\r
-       if (!BN_lshift(E->B, E->B, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(E->B, E->B, mont->p, ctx)) return 0;\r
-\r
-       if (!BN_lshift(E->h, E->h, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(E->h, E->h, mont->p, ctx)) return 0;\r
-\r
-       E->is_in_mont = 1;\r
-       return 1;\r
-\r
-}\r
-\r
-\r
-int EC_from_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (!E->is_in_mont) return 1;\r
-\r
-       if (!BN_mont_red(E->A, mont, ctx)) return 0;\r
-       if (!BN_mont_red(E->B, mont, ctx)) return 0;\r
-       if (!BN_mont_red(E->h, mont, ctx)) return 0;\r
-\r
-       E->is_in_mont = 0;\r
-       return 1;\r
-}\r
-#endif /* MONTGOMERY */\r
-\r
-int EC_set_half(EC *E)\r
-/* h <- 1/2 mod p = (p + 1)/2 */\r
-{\r
-       assert(E != NULL);\r
-       assert(E->p != NULL);\r
-       assert(E->h != NULL);\r
-       assert(!E->is_in_mont);\r
-\r
-       if (BN_copy(E->h, E->p) == NULL) return 0; \r
-       if (!BN_add_word(E->h, 1)) return 0;\r
-       if (!BN_rshift1(E->h, E->h)) return 0; \r
-       return 1;\r
-}\r
+/*
+ *
+ *     ec.c
+ *
+ *     Elliptic Curve Arithmetic Functions
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "ec.h"
+#include "bn_modfs.h"
+
+
+
+EC *EC_new()
+{
+       EC *ret;
+
+       ret=(EC *)malloc(sizeof(EC));
+       if (ret == NULL) return NULL;
+       ret->A = BN_new();
+       ret->B = BN_new();
+       ret->p = BN_new();
+       ret->h = BN_new();
+       ret->is_in_mont = 0;
+
+       if (ret->A == NULL || ret->B == NULL || ret->p == NULL || ret->h == NULL)
+       {
+               if (ret->A != NULL) BN_free(ret->A);
+               if (ret->B != NULL) BN_free(ret->B);
+               if (ret->p != NULL) BN_free(ret->p);
+               if (ret->h != NULL) BN_free(ret->h);
+               free(ret);
+               return(NULL);
+       }
+       return(ret);
+}
+
+
+void EC_clear_free(EC *E)
+{
+       if (E == NULL) return;
+
+       if (E->A != NULL) BN_clear_free(E->A);
+       if (E->B != NULL) BN_clear_free(E->B);
+       if (E->p != NULL) BN_clear_free(E->p);
+       if (E->h != NULL) BN_clear_free(E->h);
+       E->is_in_mont = 0;
+       free(E);
+}
+
+
+#ifdef MONTGOMERY
+int EC_to_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       assert(ctx != NULL);
+
+       if (E->is_in_mont) return 1;
+
+       if (!BN_lshift(E->A, E->A, mont->R_num_bits)) return 0;
+       if (!BN_mod(E->A, E->A, mont->p, ctx)) return 0;
+
+       if (!BN_lshift(E->B, E->B, mont->R_num_bits)) return 0;
+       if (!BN_mod(E->B, E->B, mont->p, ctx)) return 0;
+
+       if (!BN_lshift(E->h, E->h, mont->R_num_bits)) return 0;
+       if (!BN_mod(E->h, E->h, mont->p, ctx)) return 0;
+
+       E->is_in_mont = 1;
+       return 1;
+
+}
+
+
+int EC_from_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       assert(ctx != NULL);
+
+       if (!E->is_in_mont) return 1;
+
+       if (!BN_mont_red(E->A, mont, ctx)) return 0;
+       if (!BN_mont_red(E->B, mont, ctx)) return 0;
+       if (!BN_mont_red(E->h, mont, ctx)) return 0;
+
+       E->is_in_mont = 0;
+       return 1;
+}
+#endif /* MONTGOMERY */
+
+int EC_set_half(EC *E)
+/* h <- 1/2 mod p = (p + 1)/2 */
+{
+       assert(E != NULL);
+       assert(E->p != NULL);
+       assert(E->h != NULL);
+       assert(!E->is_in_mont);
+
+       if (BN_copy(E->h, E->p) == NULL) return 0; 
+       if (!BN_add_word(E->h, 1)) return 0;
+       if (!BN_rshift1(E->h, E->h)) return 0; 
+       return 1;
+}

diff --git a/crypto/ec/ec.h b/crypto/ec/ec.h
index 97d55cb2ccb30bfc64d88e65780f751f6f0953d6..422cbebd10068740b56748dcbc9ccc2b14ad221c 100644 (file)
--- a/crypto/ec/ec.h
+++ b/crypto/ec/ec.h
@@ -1,86 +1,86 @@
-/*\r
- *\r
- *     ec.h\r
- *\r
- *     Elliptic Curve Arithmetic Functions\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-\r
-#ifndef HEADER_EC_H\r
-#define HEADER_EC_H\r
-\r
-\r
-#include "bn.h"\r
-#include "bn_mont2.h"\r
-\r
-typedef struct bn_ec_struct            /* E: y^2 = x^3 + Ax + B  (mod p) */\r
-{\r
-       BIGNUM  *A, *B, *p, *h;         /* h = 1/2 mod p = (p + 1)/2 */\r
-       int is_in_mont;\r
-} EC;\r
-\r
-typedef struct bn_ec_point_struct /* P = [X, Y, Z] */\r
-{\r
-       BIGNUM  *X, *Y, *Z;\r
-       int is_in_mont;\r
-} EC_POINT;\r
-\r
-typedef struct bn_ecp_precompute_struct /* Pi[i] = [2i + 1]P   i = 0..2^{r-1} - 1 */\r
-{\r
-       int r;\r
-       EC_POINT **Pi;\r
-} ECP_PRECOMPUTE;\r
-\r
-\r
-#define ECP_is_infty(P) (BN_is_zero(P->Z))\r
-#define ECP_is_norm(P) (BN_is_one(P->Z))\r
-\r
-#define ECP_mont_minus(P, mont) (ECP_minus((P), (mont)->p))\r
-\r
-\r
-EC *EC_new();\r
-void EC_clear_free(EC *E);\r
-int EC_set_half(EC *E);\r
-#ifdef MONTGOMERY\r
-int EC_to_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int EC_from_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-#endif /* MONTGOMERY */\r
-\r
-\r
-EC_POINT *ECP_new();\r
-void ECP_clear_free(EC_POINT *P);\r
-void ECP_clear_free_precompute(ECP_PRECOMPUTE *prec);\r
-\r
-EC_POINT *ECP_generate(BIGNUM *x, BIGNUM *z, EC *E, BN_CTX *ctx);\r
-EC_POINT *ECP_dup(EC_POINT *P);\r
-int ECP_copy(EC_POINT *R, EC_POINT *P);\r
-int ECP_normalize(EC_POINT *P, EC *E, BN_CTX *ctx);\r
-EC_POINT *ECP_minus(EC_POINT *P, BIGNUM *p);\r
-int ECP_is_on_ec(EC_POINT *P, EC *E, BN_CTX *ctx);\r
-int ECP_ecp2bin(EC_POINT *P, unsigned char *to, int form); /* form(ANSI 9.62): 1-compressed; 2-uncompressed; 3-hybrid */\r
-int ECP_bin2ecp(unsigned char *from, int len, EC_POINT *P, EC *E, BN_CTX *ctx);\r
-\r
-#ifdef SIMPLE\r
-int ECP_cmp(EC_POINT *P, EC_POINT *Q, BIGNUM *p, BN_CTX *ctx);\r
-int ECP_double(EC_POINT *R, EC_POINT *P, EC *E, BN_CTX *ctx);\r
-int ECP_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_CTX *ctx);\r
-ECP_PRECOMPUTE *ECP_precompute(int r, EC_POINT *P, EC *E, BN_CTX *ctx);\r
-int ECP_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_CTX *ctx);\r
-#endif /* SIMPLE */\r
-\r
-#ifdef MONTGOMERY\r
-int ECP_to_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int ECP_from_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int ECP_mont_cmp(EC_POINT *P, EC_POINT *Q, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int ECP_mont_double(EC_POINT *R, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int ECP_mont_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-ECP_PRECOMPUTE *ECP_mont_precompute(int r, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int ECP_mont_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-int ECP_mont_multiply2(EC_POINT *R, BIGNUM *k, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);\r
-#endif /* MONTGOMERY */\r
-\r
+/*
+ *
+ *     ec.h
+ *
+ *     Elliptic Curve Arithmetic Functions
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+
+#ifndef HEADER_EC_H
+#define HEADER_EC_H
+
+
+#include "bn.h"
+#include "bn_mont2.h"
+
+typedef struct bn_ec_struct            /* E: y^2 = x^3 + Ax + B  (mod p) */
+{
+       BIGNUM  *A, *B, *p, *h;         /* h = 1/2 mod p = (p + 1)/2 */
+       int is_in_mont;
+} EC;
+
+typedef struct bn_ec_point_struct /* P = [X, Y, Z] */
+{
+       BIGNUM  *X, *Y, *Z;
+       int is_in_mont;
+} EC_POINT;
+
+typedef struct bn_ecp_precompute_struct /* Pi[i] = [2i + 1]P   i = 0..2^{r-1} - 1 */
+{
+       int r;
+       EC_POINT **Pi;
+} ECP_PRECOMPUTE;
+
+
+#define ECP_is_infty(P) (BN_is_zero(P->Z))
+#define ECP_is_norm(P) (BN_is_one(P->Z))
+
+#define ECP_mont_minus(P, mont) (ECP_minus((P), (mont)->p))
+
+
+EC *EC_new();
+void EC_clear_free(EC *E);
+int EC_set_half(EC *E);
+#ifdef MONTGOMERY
+int EC_to_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int EC_from_montgomery(EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+#endif /* MONTGOMERY */
+
+
+EC_POINT *ECP_new();
+void ECP_clear_free(EC_POINT *P);
+void ECP_clear_free_precompute(ECP_PRECOMPUTE *prec);
+
+EC_POINT *ECP_generate(BIGNUM *x, BIGNUM *z, EC *E, BN_CTX *ctx);
+EC_POINT *ECP_dup(EC_POINT *P);
+int ECP_copy(EC_POINT *R, EC_POINT *P);
+int ECP_normalize(EC_POINT *P, EC *E, BN_CTX *ctx);
+EC_POINT *ECP_minus(EC_POINT *P, BIGNUM *p);
+int ECP_is_on_ec(EC_POINT *P, EC *E, BN_CTX *ctx);
+int ECP_ecp2bin(EC_POINT *P, unsigned char *to, int form); /* form(ANSI 9.62): 1-compressed; 2-uncompressed; 3-hybrid */
+int ECP_bin2ecp(unsigned char *from, int len, EC_POINT *P, EC *E, BN_CTX *ctx);
+
+#ifdef SIMPLE
+int ECP_cmp(EC_POINT *P, EC_POINT *Q, BIGNUM *p, BN_CTX *ctx);
+int ECP_double(EC_POINT *R, EC_POINT *P, EC *E, BN_CTX *ctx);
+int ECP_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_CTX *ctx);
+ECP_PRECOMPUTE *ECP_precompute(int r, EC_POINT *P, EC *E, BN_CTX *ctx);
+int ECP_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_CTX *ctx);
+#endif /* SIMPLE */
+
+#ifdef MONTGOMERY
+int ECP_to_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int ECP_from_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int ECP_mont_cmp(EC_POINT *P, EC_POINT *Q, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int ECP_mont_double(EC_POINT *R, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int ECP_mont_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+ECP_PRECOMPUTE *ECP_mont_precompute(int r, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int ECP_mont_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+int ECP_mont_multiply2(EC_POINT *R, BIGNUM *k, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx);
+#endif /* MONTGOMERY */
+
 #endif
\ No newline at end of file

diff --git a/crypto/ec/ec_point.c b/crypto/ec/ec_point.c
index fee5078bf84ec7495c1611429a1b90d1e28bfcd4..bbf8a92d3aec6ff6481b34242643500a2bd42253 100644 (file)
--- a/crypto/ec/ec_point.c
+++ b/crypto/ec/ec_point.c
@@ -1,1461 +1,1461 @@
-/*\r
- *\r
- *     ec_point.c\r
- *\r
- *     Elliptic Curve Arithmetic Functions\r
- *\r
- *     Copyright (C) Lenka Fibikova 2000\r
- *\r
- *\r
- */\r
-\r
-#include <stdio.h>\r
-#include <stdlib.h>\r
-#include <assert.h>\r
-#include <memory.h>\r
-\r
-#include "bn.h"\r
-\r
-#include "bn_modfs.h"\r
-#include "bn_mont2.h"\r
-#include "ec.h"\r
-\r
-EC_POINT *ECP_new()\r
-{\r
-       EC_POINT *ret;\r
-\r
-       ret=(EC_POINT *)malloc(sizeof(EC_POINT));\r
-       if (ret == NULL) return NULL;\r
-       ret->X = BN_new();\r
-       ret->Y = BN_new();\r
-       ret->Z = BN_new();\r
-       ret->is_in_mont = 0;\r
-\r
-       if (ret->X == NULL || ret->Y == NULL || ret->Z == NULL) \r
-       {\r
-               if (ret->X != NULL) BN_free(ret->X);\r
-               if (ret->Y != NULL) BN_free(ret->Y);\r
-               if (ret->Z != NULL) BN_free(ret->Z);\r
-               free(ret);\r
-               return(NULL);\r
-       }\r
-       return(ret);\r
-}\r
-\r
-void ECP_clear_free(EC_POINT *P)\r
-{\r
-       if (P == NULL) return;\r
-       \r
-       P->is_in_mont = 0;\r
-       if (P->X != NULL) BN_clear_free(P->X);\r
-       if (P->Y != NULL) BN_clear_free(P->Y);\r
-       if (P->Z != NULL) BN_clear_free(P->Z);\r
-       free(P);\r
-}\r
-\r
-void ECP_clear_free_precompute(ECP_PRECOMPUTE *prec)\r
-{\r
-       int i;\r
-       int max;\r
-\r
-       if (prec == NULL) return;\r
-       if (prec->Pi != NULL)\r
-       {\r
-               max = 1;\r
-               max <<= (prec->r - 1);\r
-\r
-               for (i = 0; i < max; i++)\r
-               {\r
-                       if (prec->Pi[i] != NULL) ECP_clear_free(prec->Pi[i]);\r
-               }\r
-       }\r
-       free(prec);\r
-}\r
-\r
-int ECP_is_on_ec(EC_POINT *P, EC *E, BN_CTX *ctx)\r
-{\r
-       BIGNUM *n0, *n1, *n2, *p;\r
-       int Pnorm;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       assert(!P->is_in_mont);\r
-\r
-       if (ECP_is_infty(P)) return 1;\r
-       \r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       ctx->tos += 3;\r
-\r
-\r
-       p = E->p;\r
-\r
-       Pnorm = (ECP_is_norm(P));\r
-\r
-       if (!Pnorm)\r
-       {\r
-               if (!BN_mod_mul(n0, P->Z, P->Z, p, ctx)) goto err;\r
-               if (!BN_mod_mul(n1, n0, n0, p, ctx)) goto err;\r
-               if (!BN_mod_mul(n2, n0, n1, p, ctx)) goto err;\r
-       }\r
-\r
-       if (!BN_mod_mul(n0, P->X, P->X, p, ctx)) goto err;\r
-       if (!BN_mod_mul(n0, n0, P->X, p, ctx)) goto err;\r
-\r
-       if (Pnorm)\r
-       {\r
-               if (!BN_mod_mul(n1, P->X, E->A, p, ctx)) goto err;\r
-       }\r
-       else\r
-       {\r
-               if (!BN_mod_mul(n1, n1, P->X, p, ctx)) goto err;\r
-               if (!BN_mod_mul(n1, n1, E->A, p, ctx)) goto err;\r
-       }\r
-       if (!BN_mod_add(n0, n0, n1, p, ctx)) goto err;\r
-\r
-       if (Pnorm)\r
-       {\r
-               if (!BN_mod_add(n0, n0, E->B, p, ctx)) goto err;\r
-       }\r
-       else\r
-       {\r
-               if (!BN_mod_mul(n2, n2, E->B,  p, ctx)) goto err;\r
-               if (!BN_mod_add(n0, n0, n2, p, ctx)) goto err;\r
-       }\r
-\r
-       if (!BN_mod_mul(n1, P->Y, P->Y, p, ctx)) goto err;\r
-\r
-       if (BN_cmp(n0, n1)) \r
-       { \r
-               ctx->tos -= 3;\r
-               return 0;\r
-       }\r
-\r
-       ctx->tos -= 3;\r
-       return 1;\r
-       \r
-err:\r
-       ctx->tos -= 3;\r
-       return -1;\r
-}\r
-\r
-\r
-EC_POINT *ECP_generate(BIGNUM *x, BIGNUM *z,EC *E, BN_CTX *ctx)\r
-/* x == NULL || z = 0  -> point of infinity    */\r
-/* z == NULL || z = 1  -> normalized           */\r
-{\r
-       BIGNUM *n0, *n1;\r
-       EC_POINT *ret;\r
-       int Pnorm, Pinfty, X0, A0;\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       Pinfty = (x == NULL);\r
-       Pnorm = (z == NULL);\r
-       if (!Pnorm) \r
-       {\r
-               Pnorm = BN_is_one(z);\r
-               Pinfty = (Pinfty || BN_is_zero(z));\r
-       }\r
-\r
-       if (Pinfty) \r
-       {\r
-               if ((ret = ECP_new()) == NULL) return NULL;\r
-               if (!BN_zero(ret->Z)) \r
-               { \r
-                       ECP_clear_free(ret);\r
-                       return NULL;\r
-               }\r
-               return ret;\r
-       }\r
-\r
-       X0 = BN_is_zero(x);\r
-       A0 = BN_is_zero(E->A);\r
-\r
-       if ((ret = ECP_new()) == NULL) return NULL;\r
-\r
-       ret->is_in_mont = 0;\r
-\r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       if (!BN_zero(n0)) return NULL;\r
-       if (!BN_zero(n1)) return NULL;\r
-\r
-       ctx->tos += 2;\r
-\r
-       if (!X0)\r
-       {\r
-               if (!BN_mod_sqr(n0, x, E->p, ctx)) goto err;\r
-               if (!BN_mod_mul(n0, n0, x, E->p, ctx)) goto err;        /* x^3 */\r
-       }\r
-\r
-       if (!X0 && !A0)\r
-       {\r
-               if (!BN_mod_mul(n1, E->A, x, E->p, ctx)) goto err;      /* Ax */\r
-               if (!BN_mod_add(n0, n0, n1, E->p, ctx)) goto err;       /* x^3 + Ax */\r
-       }\r
-\r
-       if (!BN_is_zero(E->B))\r
-               if (!BN_mod_add(n0, n0, E->B, E->p, ctx)) goto err;     /* x^3 + Ax +B */\r
-\r
-       if (!BN_mod_sqrt(ret->Y, n0, E->p, ctx)) goto err;\r
-       if (BN_copy(ret->X, x) == NULL) goto err;\r
-       \r
-       if (Pnorm)\r
-       {\r
-               if (!BN_one(ret->Z)) goto err;\r
-       }\r
-       else\r
-       {\r
-               if (BN_copy(ret->Z, z) == NULL) goto err;\r
-               if (!BN_mod_sqr(n0, z, E->p, ctx)) goto err;\r
-               if (!BN_mod_mul(ret->X, ret->X, n0, E->p, ctx)) goto err;\r
-               if (!BN_mod_mul(n0, n0, z, E->p, ctx)) goto err;\r
-               if (!BN_mod_mul(ret->Y, ret->Y, n0, E->p, ctx)) goto err;\r
-       }\r
-\r
-#ifdef TEST\r
-       if (!ECP_is_on_ec(ret, E, ctx)) goto err;\r
-#endif\r
-       \r
-       ctx->tos -= 2;\r
-       return ret;\r
-\r
-err:\r
-       if (ret != NULL) ECP_clear_free(ret);\r
-       ctx->tos -= 2;\r
-       return NULL;\r
-}\r
-\r
-int ECP_ecp2bin(EC_POINT *P, unsigned char *to, int form)\r
-/* form =      1 ... compressed\r
-                       2 ... uncompressed\r
-                       3 ... hybrid */\r
-{\r
-       int bytes, bx, by;\r
-\r
-       assert (P != NULL);\r
-       assert (P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-       assert (!P->is_in_mont);\r
-       assert (ECP_is_norm(P) || ECP_is_infty(P));\r
-       assert (to != NULL);\r
-       assert (form > 0 && form < 4);\r
-\r
-       if (BN_is_zero(P->Z))\r
-       {\r
-               to[0] = 0;\r
-               return 1;\r
-       }\r
-\r
-       bx = BN_num_bytes(P->X);\r
-       if (form == 1 ) bytes = bx + 1;\r
-       else \r
-       {\r
-               by = BN_num_bytes(P->Y);\r
-               bytes = (bx > by ? bx : by);\r
-               bytes = bytes * 2 + 1;\r
-       }\r
-       memset(to, 0, bytes);\r
-\r
-       switch (form)\r
-       {\r
-       case 1: to[0] = 2;      break;\r
-       case 2: to[0] = 4;      break;\r
-       case 3: to[0] = 6;      break;\r
-       }\r
-       if (form != 2) to[0] += BN_is_bit_set(P->Y, 0);\r
-\r
-       \r
-       if ((BN_bn2bin(P->X, to + 1)) != bx) return 0;\r
-       if (form != 1)\r
-       {\r
-               if ((BN_bn2bin(P->Y, to + bx + 1)) != by) return 0;\r
-       }\r
-\r
-       return bytes;\r
-}\r
-\r
-int ECP_bin2ecp(unsigned char *from, int len, EC_POINT *P, EC *E, BN_CTX *ctx)\r
-{\r
-       int y;\r
-       BIGNUM *x;\r
-       EC_POINT *pp;\r
-\r
-       assert (E != NULL);\r
-       assert (E->A != NULL && E->B != NULL && E->p != NULL);\r
-       assert (!E->is_in_mont);\r
-\r
-       assert (ctx != NULL);\r
-       assert (from != NULL);\r
-       assert (P != NULL);\r
-       assert (P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       if (len == 1 && from[0] != 0) return 0;\r
-\r
-       if (len == 0 || len == 1)\r
-       { \r
-               if (!BN_zero(P->Z)) return 0;\r
-               return 1;\r
-       }\r
-\r
-       switch (from[0])\r
-       {\r
-       case 2:\r
-       case 3:\r
-               y = from[0] - 2;\r
-               if ((x = BN_new()) == NULL) return 0;\r
-               if (BN_bin2bn(from + 1, len - 1, x) == NULL) return 0;\r
-\r
-               pp = ECP_generate(x, NULL, E, ctx);\r
-               BN_clear_free(x);\r
-               if (pp == NULL) return 0;\r
-\r
-               ECP_copy(P, pp);\r
-               ECP_clear_free(pp);\r
-\r
-               if (BN_is_bit_set(P->Y, 0) != y)\r
-                       if (!BN_sub(P->Y, E->p, P->Y)) return 0;\r
-               break;\r
-\r
-       case 4:\r
-       case 6:\r
-       case 7:\r
-               y = (len - 1)/2;\r
-               if (BN_bin2bn(from + 1, y, P->X) == NULL) return 0;\r
-               if (BN_bin2bn(from + y + 1, y, P->Y) == NULL) return 0;\r
-               if (!BN_set_word(P->Z, 1)) return 0;\r
-               break;\r
-\r
-       default:\r
-               assert(0);\r
-\r
-       }\r
-\r
-       if (!ECP_is_on_ec(P, E, ctx)) return 0;\r
-       return 1;\r
-}\r
-\r
-int ECP_normalize(EC_POINT *P, EC *E, BN_CTX *ctx)\r
-{\r
-       BIGNUM *z, *zm;\r
-\r
-       assert (P != NULL);\r
-       assert (P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert (E != NULL);\r
-       assert (E->A != NULL && E->B != NULL && E->p != NULL);\r
-\r
-       assert (ctx != NULL);\r
-\r
-       if (ECP_is_norm(P)) return 1;\r
-       if (ECP_is_infty(P)) return 0;\r
-\r
-       if ((zm = BN_mod_inverse(P->Z, E->p, ctx)) == NULL) return 0;\r
-\r
-       assert(!P->is_in_mont);\r
-\r
-\r
-       z = ctx->bn[ctx->tos]; \r
-       ctx->tos++;\r
-\r
-       if (!BN_mod_mul(z, zm, zm, E->p, ctx)) goto err;\r
-       if (!BN_mod_mul(P->X, P->X, z, E->p, ctx)) goto err;\r
-\r
-       if (!BN_mod_mul(z, z, zm, E->p, ctx)) goto err;\r
-       if (!BN_mod_mul(P->Y, P->Y, z, E->p, ctx)) goto err;\r
-\r
-       if (!BN_one(P->Z)) goto err;\r
-\r
-       if (zm != NULL) BN_clear_free(zm);\r
-\r
-       ctx->tos--;\r
-       return 1;\r
-\r
-err:\r
-       if (zm != NULL) BN_clear_free(zm);\r
-       ctx->tos--;\r
-       return 0;\r
-}\r
-\r
-int ECP_copy(EC_POINT *R, EC_POINT *P)\r
-{\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       if (BN_copy(R->X, P->X) == NULL) return 0;\r
-       if (BN_copy(R->Y, P->Y) == NULL) return 0;\r
-       if (BN_copy(R->Z, P->Z) == NULL) return 0;\r
-       R->is_in_mont = P->is_in_mont;\r
-\r
-       return 1;\r
-}\r
-\r
-EC_POINT *ECP_dup(EC_POINT *P)\r
-{\r
-       EC_POINT *ret;\r
-\r
-       ret = ECP_new();\r
-       if (ret == NULL) return NULL;\r
-\r
-       if (!ECP_copy(ret, P))\r
-       {\r
-               ECP_clear_free(ret);\r
-               return(NULL);\r
-       }\r
-\r
-       return(ret);\r
-}\r
-\r
-\r
-EC_POINT *ECP_minus(EC_POINT *P, BIGNUM *p) /* mont || non-mont */\r
-{\r
-       EC_POINT *ret;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(p != NULL);\r
-\r
-       assert(BN_cmp(P->Y, p) < 0);\r
-\r
-       ret = ECP_dup(P);\r
-       if (ret == NULL) return NULL;\r
-\r
-       if (BN_is_zero(ret->Y)) return ret;\r
-\r
-       if (!BN_sub(ret->Y, p, ret->Y))\r
-       {\r
-               ECP_clear_free(ret);\r
-               return NULL;\r
-       }\r
-\r
-       return ret;\r
-}\r
-\r
-\r
-#ifdef SIMPLE\r
-int ECP_cmp(EC_POINT *P, EC_POINT *Q, BIGNUM *p, BN_CTX *ctx)\r
-/* return values: \r
-       -2 ... error\r
-        0 ... P = Q \r
-       -1 ... P = -Q\r
-        1 ... else\r
-*/\r
-{\r
-       BIGNUM *n0, *n1, *n2, *n3, *n4;\r
-       int Pnorm, Qnorm;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(Q != NULL);\r
-       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);\r
-\r
-       assert(p != NULL);\r
-       assert(ctx != NULL);\r
-\r
-       assert(!P->is_in_mont);\r
-       assert(!Q->is_in_mont);\r
-\r
-       if (ECP_is_infty(P) && ECP_is_infty(Q)) return 0;\r
-       if (ECP_is_infty(P) || ECP_is_infty(Q)) return 1;\r
-\r
-       \r
-       Pnorm = (ECP_is_norm(P));\r
-       Qnorm = (ECP_is_norm(Q));\r
-       \r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       n3 = ctx->bn[ctx->tos + 3]; \r
-       n4 = ctx->bn[ctx->tos + 4]; \r
-       ctx->tos += 5;\r
-       \r
-       if (Qnorm)\r
-       {\r
-               if (BN_copy(n1, P->X) == NULL) goto err;                        /* L1 = x_p */\r
-               if (BN_copy(n2, P->Y) == NULL) goto err;                        /* L2 = y_p */\r
-       }\r
-       else\r
-       {\r
-               if (!BN_sqr(n0, Q->Z, ctx)) goto err;\r
-               if (!BN_mod_mul(n1, P->X, n0, p, ctx)) goto err;        /* L1 = x_p * z_q^2 */\r
-\r
-               if (!BN_mod_mul(n0, n0, Q->Z, p, ctx)) goto err; \r
-               if (!BN_mod_mul(n2, P->Y, n0, p, ctx)) goto err;        /* L2 = y_p * z_q^3 */\r
-       }\r
-\r
-       if (Pnorm)\r
-       {\r
-               if (BN_copy(n3, Q->X) == NULL) goto err;                        /* L3 = x_q */\r
-               if (BN_copy(n4, Q->Y) == NULL) goto err;                        /* L4 = y_q */\r
-       }\r
-       else\r
-       {\r
-               if (!BN_sqr(n0, P->Z, ctx)) goto err;\r
-               if (!BN_mod_mul(n3, Q->X, n0, p, ctx)) goto err;        /* L3 = x_q * z_p^2 */\r
-\r
-               if (!BN_mod_mul(n0, n0, P->Z, p, ctx)) goto err; \r
-               if (!BN_mod_mul(n4, Q->Y, n0, p, ctx)) goto err;        /* L4 = y_q * z_p^3 */\r
-       }\r
-\r
-       if (!BN_mod_sub(n0, n1, n3, p, ctx)) goto err;                  /* L5 = L1 - L3 */\r
-\r
-       if (!BN_is_zero(n0))\r
-       {\r
-               ctx->tos -= 5;\r
-               return 1;\r
-       }\r
-       \r
-       if (!BN_mod_sub(n0, n2, n4, p, ctx)) goto err;                  /* L6 = L2 - L4 */\r
-\r
-       if (!BN_is_zero(n0))\r
-       {\r
-               ctx->tos -= 5;\r
-               return -1;\r
-       }\r
-\r
-       ctx->tos -= 5;\r
-       return 0;\r
-\r
-err:\r
-       ctx->tos -= 5;\r
-       return -2;\r
-}\r
-\r
-int ECP_double(EC_POINT *R, EC_POINT *P, EC *E, BN_CTX *ctx)\r
-/* R <- 2P (on E) */\r
-{\r
-       BIGNUM *n0, *n1, *n2, *n3, *p;\r
-       int Pnorm, A0;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       assert(!P->is_in_mont);\r
-\r
-       if (ECP_is_infty(P))\r
-       {\r
-               if (!BN_zero(R->Z)) return 0;\r
-               return 1;\r
-       }\r
-\r
-       Pnorm = (ECP_is_norm(P));\r
-       A0 = (BN_is_zero(E->A));\r
-\r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       n3 = ctx->bn[ctx->tos + 3]; \r
-       ctx->tos += 4;\r
-\r
-       p = E->p;\r
-\r
-       /* L1 */\r
-       if (Pnorm || A0)\r
-       {\r
-               if (!BN_mod_sqr(n1, P->X, p, ctx)) goto err;\r
-               if (!BN_mul_word(n1, 3)) goto err;  \r
-               if (!A0)                                   /* if A = 0: L1 = 3 * x^2 + a * z^4 = 3 * x ^2    */\r
-                       if (!BN_mod_add(n1, n1, E->A, p, ctx)) goto err; /* L1 = 3 * x^2 + a * z^4 = 3 * x^2 + a */\r
-       }\r
-       else\r
-       {\r
-               if (!BN_mod_sqr(n0, P->Z, p, ctx)) goto err;\r
-               if (!BN_mod_mul(n0, n0, n0, p, ctx)) goto err;\r
-               if (!BN_mod_mul(n0, n0, E->A, p, ctx)) goto err; \r
-               if (!BN_mod_sqr(n1, P->X, p, ctx)) goto err;\r
-               if (!BN_mul_word(n1, 3)) goto err;  \r
-               if (!BN_mod_add(n1, n1, n0, p, ctx)) goto err;          /* L1 = 3 * x^2 + a * z^4 */\r
-       }\r
-\r
-       /* Z */\r
-       if (Pnorm)\r
-       {\r
-               if (BN_copy(n0, P->Y) == NULL) goto err;\r
-       }\r
-       else\r
-       {\r
-               if (!BN_mod_mul(n0, P->Y, P->Z, p, ctx)) goto err; \r
-       }\r
-       if (!BN_lshift1(n0, n0)) goto err; \r
-       if (!BN_smod(R->Z, n0, p, ctx)) goto err;                               /* Z = 2 * y * z */\r
-\r
-       /* L2 */\r
-       if (!BN_mod_sqr(n3, P->Y, p, ctx)) goto err;\r
-       if (!BN_mod_mul(n2, P->X, n3, p, ctx)) goto err; \r
-       if (!BN_lshift(n2, n2, 2)) goto err; \r
-       if (!BN_smod(n2, n2, p, ctx)) goto err;                                 /* L2 = 4 * x * y^2 */\r
-\r
-       /* X */\r
-       if (!BN_lshift1(n0, n2)) goto err; \r
-       if (!BN_mod_sqr(R->X, n1, p, ctx)) goto err;\r
-       if (!BN_mod_sub(R->X, R->X, n0, p, ctx)) goto err;              /* X = L1^2 - 2 * L2 */\r
-       \r
-       /* L3 */\r
-       if (!BN_mod_sqr(n0, n3, p, ctx)) goto err;\r
-       if (!BN_lshift(n3, n0, 3)) goto err; \r
-       if (!BN_smod(n3, n3, p, ctx)) goto err;                                 /* L3 = 8 * y^4 */\r
-       \r
-       /* Y */\r
-       if (!BN_mod_sub(n0, n2, R->X, p, ctx)) goto err; \r
-       if (!BN_mod_mul(n0, n1, n0, p, ctx)) goto err; \r
-       if (!BN_mod_sub(R->Y, n0, n3, p, ctx)) goto err;                /* Y = L1 * (L2 - X) - L3 */\r
-\r
-\r
-#ifdef TEST\r
-       if (!ECP_is_on_ec(R, E, ctx)) return 0;\r
-#endif\r
-\r
-       ctx->tos -= 4;\r
-       return 1;\r
-\r
-err:\r
-       ctx->tos -= 4;\r
-       return 0;\r
-}\r
-\r
-int ECP_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_CTX *ctx)\r
-/* R <- P + Q (on E) */\r
-{\r
-       BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6, *p;\r
-       int Pnorm, Qnorm;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(Q != NULL);\r
-       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-       assert(!BN_is_zero(E->h));;\r
-\r
-       assert(ctx != NULL);\r
-\r
-       assert(!P->is_in_mont);\r
-       assert(!Q->is_in_mont);\r
-\r
-       if (P == Q) return ECP_double(R, P, E, ctx);\r
-\r
-       if (ECP_is_infty(P)) return ECP_copy(R, Q);\r
-       if (ECP_is_infty(Q)) return ECP_copy(R, P);\r
-       \r
-       Pnorm = (ECP_is_norm(P));\r
-       Qnorm = (ECP_is_norm(Q));\r
-       \r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       n3 = ctx->bn[ctx->tos + 3]; \r
-       n4 = ctx->bn[ctx->tos + 4]; \r
-       n5 = ctx->bn[ctx->tos + 5]; \r
-       n6 = ctx->bn[ctx->tos + 6]; \r
-       ctx->tos += 7;\r
-       p = E->p;\r
-       \r
-       /* L1; L2 */\r
-       if (Qnorm)\r
-       {\r
-               if (BN_copy(n1, P->X) == NULL) goto err;         /* L1 = x_p */\r
-               if (BN_copy(n2, P->Y) == NULL) goto err;         /* L2 = y_p */\r
-       }\r
-       else\r
-       {\r
-               if (!BN_sqr(n0, Q->Z, ctx)) goto err;\r
-               if (!BN_mod_mul(n1, P->X, n0, p, ctx)) goto err; /* L1 = x_p * z_q^2 */\r
-\r
-               if (!BN_mod_mul(n0, n0, Q->Z, p, ctx)) goto err; \r
-               if (!BN_mod_mul(n2, P->Y, n0, p, ctx)) goto err; /* L2 = y_p * z_q^3 */\r
-       }\r
-\r
-       /* L3; L4 */\r
-       if (Pnorm)\r
-       {\r
-               if (BN_copy(n3, Q->X) == NULL) goto err;         /* L3 = x_q */\r
-               if (BN_copy(n4, Q->Y) == NULL) goto err;         /* L4 = y_q */\r
-       }\r
-       else\r
-       {\r
-               if (!BN_sqr(n0, P->Z, ctx)) goto err;\r
-               if (!BN_mod_mul(n3, Q->X, n0, p, ctx)) goto err; /* L3 = x_q * z_p^2 */\r
-\r
-               if (!BN_mod_mul(n0, n0, P->Z, p, ctx)) goto err; \r
-               if (!BN_mod_mul(n4, Q->Y, n0, p, ctx)) goto err; /* L4 = y_q * z_p^3 */\r
-       }\r
-\r
-       /* L5; L6 */\r
-       if (!BN_mod_sub(n5, n1, n3, p, ctx)) goto err;          /* L5 = L1 - L3 */\r
-       if (!BN_mod_sub(n6, n2, n4, p, ctx)) goto err;          /* L6 = L2 - L4 */\r
-\r
-       /* pata */\r
-       if (BN_is_zero(n5))\r
-       {\r
-               if (BN_is_zero(n6))     /* P = Q => P + Q = 2P */\r
-               {\r
-                       ctx->tos -= 7;\r
-                       return ECP_double(R, P, E, ctx);\r
-               }\r
-               else                             /* P = -Q => P + Q = \infty */\r
-               { \r
-                       ctx->tos -= 7;\r
-                       if (!BN_zero(R->Z)) return 0;\r
-                       return 1;\r
-               }\r
-       }\r
-\r
-       /* L7; L8 */\r
-       if (!BN_mod_add(n1, n1, n3, p, ctx)) goto err;          /* L7 = L1 + L3 */\r
-       if (!BN_mod_add(n2, n2, n4, p, ctx)) goto err;          /* L8 = L2 + L4 */\r
-\r
-       /* Z */\r
-       if (Pnorm) \r
-       {\r
-               if (BN_copy(n0, Q->Z) == NULL) goto err;\r
-       }\r
-       else\r
-       {\r
-               if (!BN_mod_mul(n0, P->Z, Q->Z, p, ctx)) goto err;\r
-       }\r
-       if (!BN_mod_mul(R->Z, n0, n5, p, ctx)) goto err;        /* Z = z_p * z_q * L_5 */\r
-\r
-       /* X */\r
-       if (!BN_mod_sqr(n0, n6, p, ctx)) goto err;\r
-       if (!BN_mod_sqr(n4, n5, p, ctx)) goto err;\r
-       if (!BN_mod_mul(n3, n1, n4, p, ctx)) goto err; \r
-       if (!BN_mod_sub(R->X, n0, n3, p, ctx)) goto err;        /* X = L6^2 - L5^2 * L7 */\r
-       \r
-       /* L9 */\r
-       if (!BN_lshift1(n0, R->X)) goto err;\r
-       if (!BN_mod_sub(n0, n3, n0, p, ctx)) goto err;          /* L9 = L5^2 * L7 - 2X */\r
-\r
-       /* Y */\r
-       if (!BN_mod_mul(n0, n0, n6, p, ctx)) goto err; \r
-       if (!BN_mod_mul(n5, n4, n5, p, ctx)) goto err; \r
-       if (!BN_mod_mul(n1, n2, n5, p, ctx)) goto err; \r
-       if (!BN_mod_sub(n0, n0, n1, p, ctx)) goto err;   \r
-       if (!BN_mod_mul(R->Y, n0, E->h, p, ctx)) goto err;      /* Y = (L6 * L9 - L8 * L5^3) / 2 */\r
-\r
-\r
-\r
-#ifdef TEST\r
-       if (!ECP_is_on_ec(R, E, ctx)) return 0;\r
-#endif\r
-\r
-       ctx->tos -= 7;\r
-       return 1;\r
-\r
-err:\r
-       ctx->tos -= 7;\r
-       return 0;\r
-}\r
-\r
-\r
-ECP_PRECOMPUTE *ECP_precompute(int r, EC_POINT *P, EC *E, BN_CTX *ctx)\r
-{\r
-       ECP_PRECOMPUTE *ret;\r
-       EC_POINT *P2;\r
-       int i, max;\r
-\r
-       assert(r > 2);\r
-       assert(!P->is_in_mont);\r
-       assert(!E->is_in_mont);\r
-\r
-       ret=(ECP_PRECOMPUTE *)malloc(sizeof(ECP_PRECOMPUTE));\r
-       if (ret == NULL) return NULL;\r
-\r
-       max = 1;\r
-       max <<= (r - 1);\r
-\r
-       ret->r = 0;\r
-\r
-       ret->Pi=(EC_POINT **)malloc(sizeof(EC_POINT *) * max);\r
-       if (ret->Pi == NULL) goto err;\r
-\r
-       \r
-       /* P2 = [2]P */\r
-       if ((P2 = ECP_new()) == NULL) goto err;\r
-       if (!ECP_double(P2, P, E, ctx)) goto err;\r
-\r
-       /* P_0 = P */\r
-       if((ret->Pi[0] = ECP_dup(P)) == NULL) goto err;\r
-\r
-\r
-       /* P_i = P_(i-1) + P2 */\r
-       for (i = 1; i < max; i++)\r
-       {\r
-               if ((ret->Pi[i] = ECP_new()) == NULL) goto err;\r
-               \r
-               if (!ECP_add(ret->Pi[i], P2, ret->Pi[i - 1], E, ctx)) goto err;\r
-       }\r
-\r
-       ret->r = r;\r
-       ECP_clear_free(P2);\r
-\r
-       return ret;\r
-\r
-err:\r
-       ECP_clear_free(P2);\r
-       ECP_clear_free_precompute(ret);\r
-       return NULL;\r
-}\r
-\r
-int ECP_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_CTX *ctx)\r
-/* R = [k]P */\r
-{\r
-       int j;\r
-       int t, nextw, h, r;\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(k != NULL);\r
-       assert(!k->neg);\r
-\r
-       assert(ctx != NULL);\r
-       assert(prec != NULL);\r
-\r
-       assert(!E->is_in_mont);\r
-\r
-       if (BN_is_zero(k))\r
-       {\r
-               if (!BN_zero(R->Z)) return 0;\r
-               R->is_in_mont = 0;\r
-               return 1;\r
-       }\r
-\r
-\r
-       j = BN_num_bits(k);\r
-       j--;\r
-\r
-       r = prec->r;\r
-\r
-       if (!BN_zero(R->Z)) return 0;\r
-       R->is_in_mont = 0;\r
-\r
-       while(j >= 0)\r
-       {\r
-               if (!BN_is_bit_set(k, j))\r
-               {\r
-                       if (!ECP_double(R, R, E, ctx)) return 0;\r
-                       j--;\r
-               }\r
-               else\r
-               {\r
-                       nextw = j - r;\r
-                       if (nextw < -1) nextw = -1;\r
-                       t = nextw + 1;                  \r
-                       while(!BN_is_bit_set(k, t))\r
-                       {\r
-                               t++;\r
-                       }\r
-\r
-                       if (!ECP_double(R, R, E, ctx)) return 0;\r
-\r
-                       j--;\r
-                       if (j < t) h = 0;\r
-                       else \r
-                       {\r
-                               h = 1;\r
-                               for(; j > t; j--)\r
-                               {\r
-                                       h <<= 1;\r
-                                       if (BN_is_bit_set(k, j)) h++;\r
-                                       if (!ECP_double(R, R, E, ctx)) return 0;\r
-                               }\r
-                               if (!ECP_double(R, R, E, ctx)) return 0;\r
-                               j--;\r
-                       }\r
-\r
-                       if (!ECP_add(R, R, prec->Pi[h], E, ctx)) return 0;\r
-\r
-                       for (; j > nextw; j--)\r
-                       {\r
-                               if (!ECP_double(R, R, E, ctx)) return 0;\r
-                       }\r
-\r
-               }\r
-       }\r
-\r
-       return 1;\r
-}\r
-\r
-#endif /* SIMPLE */\r
-\r
-#ifdef MONTGOMERY\r
-\r
-int ECP_to_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (P->is_in_mont) return 1;\r
-\r
-       if (!BN_lshift(P->X, P->X, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(P->X, P->X, mont->p, ctx)) return 0;\r
-\r
-       if (!BN_lshift(P->Y, P->Y, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(P->Y, P->Y, mont->p, ctx)) return 0;\r
-\r
-       if (!BN_lshift(P->Z, P->Z, mont->R_num_bits)) return 0;\r
-       if (!BN_mod(P->Z, P->Z, mont->p, ctx)) return 0;\r
-\r
-       P->is_in_mont = 1;\r
-       return 1;\r
-}\r
-\r
-\r
-int ECP_from_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (!P->is_in_mont) return 1;\r
-\r
-       if (!BN_mont_red(P->X, mont, ctx)) return 0;\r
-       if (!BN_mont_red(P->Y, mont, ctx)) return 0;\r
-       if (!BN_mont_red(P->Z, mont, ctx)) return 0;\r
-\r
-       P->is_in_mont = 0;\r
-       return 1;\r
-}\r
-\r
-int ECP_mont_cmp(EC_POINT *P, EC_POINT *Q, BN_MONTGOMERY *mont, BN_CTX *ctx) \r
-/* return values: \r
-       -2 ... error\r
-        0 ... P = Q \r
-       -1 ... P = -Q\r
-        1 ... else\r
-*/\r
-{\r
-       BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *p;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(Q != NULL);\r
-       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (!P->is_in_mont)\r
-               if (!ECP_to_montgomery(P, mont, ctx)) return 0;\r
-\r
-       if (!Q->is_in_mont)\r
-               if (!ECP_to_montgomery(Q, mont, ctx)) return 0;\r
-\r
-\r
-       if (ECP_is_infty(P) && ECP_is_infty(Q)) return 0;\r
-       if (ECP_is_infty(P) || ECP_is_infty(Q)) return 1;\r
-\r
-       \r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       n3 = ctx->bn[ctx->tos + 3]; \r
-       n4 = ctx->bn[ctx->tos + 4]; \r
-       n5 = ctx->bn[ctx->tos + 5]; \r
-       ctx->tos += 6;\r
-\r
-       p = mont->p;\r
-       \r
-\r
-       if (!BN_mont_mod_mul(n5, Q->Z, Q->Z, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n1, P->X, n5, mont, ctx)) goto err;        /* L1 = x_p * z_q^2 */\r
-\r
-       if (!BN_mont_mod_mul(n0, n5, Q->Z, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n2, P->Y, n0, mont, ctx)) goto err;        /* L2 = y_p * z_q^3 */\r
-\r
-       if (!BN_mont_mod_mul(n5, P->Z, P->Z, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n3, Q->X, n5, mont, ctx)) goto err;        /* L3 = x_q * z_p^2 */\r
-\r
-       if (!BN_mont_mod_mul(n0, n5, P->Z, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n4, Q->Y, n0, mont, ctx)) goto err;        /* L4 = y_q * z_p^3 */\r
-\r
-\r
-       if (!BN_mont_mod_sub(n0, n1, n3, mont)) goto err;                       /* L5 = L1 - L3 */\r
-\r
-       if (!BN_is_zero(n0))\r
-       {\r
-               ctx->tos -= 6;\r
-               return 1;\r
-       }\r
-       \r
-       if (!BN_mont_mod_sub(n0, n2, n4, mont)) goto err;                       /* L6 = L2 - L4 */\r
-\r
-       if (!BN_is_zero(n0))\r
-       {\r
-               ctx->tos -= 6;\r
-               return -1;\r
-       }\r
-\r
-       ctx->tos -= 6;\r
-       return 0;\r
-\r
-err:\r
-       ctx->tos -= 6;\r
-       return -2;\r
-}\r
-\r
-\r
-int ECP_mont_double(EC_POINT *R, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-/* R <- 2P (on E) */\r
-{\r
-       BIGNUM *n0, *n1, *n2, *n3, *p;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(ctx != NULL);\r
-       \r
-       if (!P->is_in_mont)\r
-               if (!ECP_to_montgomery(P, mont, ctx)) return 0;\r
-\r
-       if (!E->is_in_mont) \r
-               if (!EC_to_montgomery(E, mont, ctx)) return 0;\r
-\r
-       R->is_in_mont = 1;\r
-\r
-       if (ECP_is_infty(P))\r
-       {\r
-               if (!BN_zero(R->Z)) return 0;\r
-               return 1;\r
-       }\r
-\r
-\r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       n3 = ctx->bn[ctx->tos + 3]; \r
-\r
-       ctx->tos += 4;\r
-\r
-       p = E->p;\r
-\r
-       /* L1 */\r
-       if (!BN_mont_mod_mul(n0, P->Z, P->Z, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n2, n0, n0, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n0, n2, E->A, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n1, P->X, P->X, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_lshift1(n2, n1, mont)) goto err;\r
-       if (!BN_mont_mod_add(n1, n1, n2, mont)) goto err;\r
-       if (!BN_mont_mod_add(n1, n1, n0, mont)) goto err;               /* L1 = 3 * x^2 + a * z^4 */\r
-\r
-       /* Z */\r
-       if (!BN_mont_mod_mul(n0, P->Y, P->Z, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_lshift1(R->Z, n0, mont)) goto err;             /* Z = 2 * y * z */\r
-\r
-       /* L2 */\r
-       if (!BN_mont_mod_mul(n3, P->Y, P->Y, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n2, P->X, n3, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_lshift(n2, n2, 2, mont)) goto err;             /* L2 = 4 * x * y^2 */\r
-\r
-       /* X */\r
-       if (!BN_mont_mod_lshift1(n0, n2, mont)) goto err; \r
-       if (!BN_mont_mod_mul(R->X, n1, n1, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_sub(R->X, R->X, n0, mont)) goto err;   /* X = L1^2 - 2 * L2 */\r
-       \r
-       /* L3 */\r
-       if (!BN_mont_mod_mul(n0, n3, n3, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_lshift(n3, n0, 3, mont)) goto err;             /* L3 = 8 * y^4 */\r
-\r
-       \r
-       /* Y */\r
-       if (!BN_mont_mod_sub(n2, n2, R->X, mont)) goto err; \r
-       if (!BN_mont_mod_mul(n0, n1, n2, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_sub(R->Y, n0, n3, mont)) goto err;             /* Y = L1 * (L2 - X) - L3 */\r
-\r
-       ctx->tos -= 4;\r
-       return 1;\r
-\r
-err:\r
-       ctx->tos -= 4;\r
-       return 0;\r
-}\r
-\r
-\r
-int ECP_mont_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-/* R <- P + Q (on E) */\r
-{\r
-       BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6, *p;\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(Q != NULL);\r
-       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-       assert(!BN_is_zero(E->h));;\r
-\r
-       assert(ctx != NULL);\r
-\r
-       if (!Q->is_in_mont)\r
-               if (!ECP_to_montgomery(Q, mont, ctx)) return 0;\r
-\r
-       if (!P->is_in_mont)\r
-               if (!ECP_to_montgomery(P, mont, ctx)) return 0;\r
-\r
-       if (!E->is_in_mont) \r
-               if (!EC_to_montgomery(E, mont, ctx)) return 0;\r
-\r
-       if (P == Q) return ECP_mont_double(R, P, E, mont, ctx);\r
-\r
-       if (ECP_is_infty(P)) return ECP_copy(R, Q);\r
-       if (ECP_is_infty(Q)) return ECP_copy(R, P);\r
-       \r
-\r
-       n0 = ctx->bn[ctx->tos]; \r
-       n1 = ctx->bn[ctx->tos + 1]; \r
-       n2 = ctx->bn[ctx->tos + 2]; \r
-       n3 = ctx->bn[ctx->tos + 3]; \r
-       n4 = ctx->bn[ctx->tos + 4]; \r
-       n5 = ctx->bn[ctx->tos + 5]; \r
-       n6 = ctx->bn[ctx->tos + 6]; \r
-       ctx->tos += 7;\r
-\r
-\r
-       p = E->p;\r
-\r
-       R->is_in_mont = 1;\r
-       \r
-       /* L1; L2 */\r
-       if (!BN_mont_mod_mul(n6, Q->Z, Q->Z, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n1, P->X, n6, mont, ctx)) goto err;        /* L1 = x_p * z_q^2 */\r
-\r
-       if (!BN_mont_mod_mul(n0, n6, Q->Z, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n2, P->Y, n0, mont, ctx)) goto err;        /* L2 = y_p * z_q^3 */\r
-\r
-\r
-       /* L3; L4 */\r
-       if (!BN_mont_mod_mul(n6, P->Z, P->Z, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n3, Q->X, n6, mont, ctx)) goto err;        /* L3 = x_q * z_p^2 */\r
-\r
-       if (!BN_mont_mod_mul(n0, n6, P->Z, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n4, Q->Y, n0, mont, ctx)) goto err;        /* L4 = y_q * z_p^3 */\r
-\r
-\r
-       /* L5; L6 */\r
-       if (!BN_mont_mod_sub(n5, n1, n3, mont)) goto err;                       /* L5 = L1 - L3 */\r
-       if (!BN_mont_mod_sub(n6, n2, n4, mont)) goto err;                       /*L6 = L2 - L4 */\r
-\r
-\r
-       /* pata */\r
-       if (BN_is_zero(n5))\r
-       {\r
-               if (BN_is_zero(n6))  /* P = Q => P + Q = 2P */\r
-               {\r
-                       ctx->tos -= 7;\r
-                       return ECP_mont_double(R, P, E, mont, ctx);\r
-               }\r
-               else                             /* P = -Q => P + Q = \infty */\r
-               { \r
-                       ctx->tos -= 7;\r
-                       if (!BN_zero(R->Z)) return 0;\r
-                       return 1;\r
-               }\r
-       }\r
-\r
-       /* L7; L8 */\r
-       if (!BN_mont_mod_add(n1, n1, n3, mont)) goto err;                       /* L7 = L1 + L3 */\r
-       if (!BN_mont_mod_add(n2, n2, n4, mont)) goto err;                       /* L8 = L2 + L4 */\r
-\r
-\r
-       /* Z */\r
-       if (!BN_mont_mod_mul(n0, P->Z, Q->Z, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(R->Z, n0, n5, mont, ctx)) goto err;        /* Z = z_p * z_q * L_5 */\r
-\r
-\r
-       /* X */\r
-       if (!BN_mont_mod_mul(n0, n6, n6, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n4, n5, n5, mont, ctx)) goto err;\r
-       if (!BN_mont_mod_mul(n3, n1, n4, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_sub(R->X, n0, n3, mont)) goto err;                     /* X = L6^2 - L5^2 * L7 */\r
-\r
-       \r
-       /* L9 */\r
-       if (!BN_mont_mod_lshift1(n0, R->X, mont)) goto err;\r
-       if (!BN_mont_mod_sub(n3, n3, n0, mont)) goto err;                       /* L9 = L5^2 * L7 - 2X */\r
-\r
-\r
-       /* Y */\r
-       if (!BN_mont_mod_mul(n0, n3, n6, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n6, n4, n5, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_mul(n1, n2, n6, mont, ctx)) goto err; \r
-       if (!BN_mont_mod_sub(n0, n0, n1, mont)) goto err;   \r
-       if (!BN_mont_mod_mul(R->Y, n0, E->h, mont, ctx)) goto err;      /* Y = (L6 * L9 - L8 * L5^3) / 2 */\r
-\r
-\r
-       ctx->tos -= 7;\r
-       return 1;\r
-\r
-err:\r
-       ctx->tos -= 7;\r
-       return 0;\r
-}\r
-\r
-\r
-ECP_PRECOMPUTE *ECP_mont_precompute(int r, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-{\r
-       ECP_PRECOMPUTE *ret;\r
-       EC_POINT *P2;\r
-       int i, max;\r
-\r
-       assert(r > 2);\r
-       assert(r < sizeof(unsigned int) * 8 - 1);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-       \r
-       if (!P->is_in_mont)\r
-               if (!ECP_to_montgomery(P, mont, ctx)) return 0;\r
-\r
-       if (!E->is_in_mont) \r
-               if (!EC_to_montgomery(E, mont, ctx)) return 0;\r
-\r
-       ret=(ECP_PRECOMPUTE *)malloc(sizeof(ECP_PRECOMPUTE));\r
-       if (ret == NULL) return NULL;\r
-\r
-       max = 1;\r
-       max <<= (r - 1);\r
-\r
-       ret->r = 0;\r
-\r
-       ret->Pi=(EC_POINT **)malloc(sizeof(EC_POINT *) * max);\r
-       if (ret->Pi == NULL) goto err;\r
-\r
-       \r
-       /* P2 = [2]P */\r
-       if ((P2 = ECP_new()) == NULL) goto err;\r
-       if (!ECP_mont_double(P2, P, E, mont, ctx)) goto err;\r
-\r
-       /* P_0 = P */\r
-       if((ret->Pi[0] = ECP_dup(P)) == NULL) goto err;\r
-\r
-\r
-       /* P_i = P_(i-1) + P2 */\r
-       for (i = 1; i < max; i++)\r
-       {\r
-               if ((ret->Pi[i] = ECP_new()) == NULL) goto err;\r
-               if (!ECP_mont_add(ret->Pi[i], P2, ret->Pi[i - 1], E, mont, ctx)) goto err;\r
-       }\r
-\r
-       ret->r = r;\r
-       ECP_clear_free(P2);\r
-\r
-       return ret;\r
-\r
-err:\r
-       ECP_clear_free(P2);\r
-       ECP_clear_free_precompute(ret);\r
-       return NULL;\r
-}\r
-\r
-int ECP_mont_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-/* R = [k]P   P = prec->Pi[0]*/\r
-{\r
-       int j;\r
-       int t, nextw, h, r;\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(k != NULL);\r
-       assert(!k->neg);\r
-\r
-       assert(ctx != NULL);\r
-       assert(prec != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       if (!E->is_in_mont) \r
-               if (!EC_to_montgomery(E, mont, ctx)) return 0;\r
-\r
-\r
-       if (BN_is_zero(k))\r
-       {\r
-               if (!BN_zero(R->Z)) return 0;\r
-               R->is_in_mont = 1;\r
-               return 1;\r
-       }\r
-\r
-       j = BN_num_bits(k);\r
-       j--;\r
-\r
-       r = prec->r;\r
-\r
-       if (!BN_zero(R->Z)) return 0;\r
-       R->is_in_mont = 1;\r
-\r
-       while(j >= 0)\r
-       {\r
-               if (!BN_is_bit_set(k, j))\r
-               {\r
-                       if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;\r
-                       j--;\r
-               }\r
-               else\r
-               {\r
-                       nextw = j - r;\r
-                       if (nextw < -1) nextw = -1;\r
-                       t = nextw + 1;                  \r
-                       while(!BN_is_bit_set(k, t))\r
-                       {\r
-                               t++;\r
-                       }\r
-\r
-                       if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;\r
-\r
-                       j--;\r
-                       if (j < t) h = 0;\r
-                       else \r
-                       {\r
-                               h = 1;\r
-                               for(; j > t; j--)\r
-                               {\r
-                                       h <<= 1;\r
-                                       if (BN_is_bit_set(k, j)) h++;\r
-                                       if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;\r
-                               }\r
-                               if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;\r
-                               j--;\r
-                       }\r
-\r
-                       if (!ECP_mont_add(R, R, prec->Pi[h], E, mont, ctx)) return 0;\r
-\r
-                       for (; j > nextw; j--)\r
-                       {\r
-                               if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;\r
-                       }\r
-\r
-               }\r
-       }\r
-\r
-       return 1;\r
-}\r
-\r
-\r
-int ECP_mont_multiply2(EC_POINT *R, BIGNUM *k, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)\r
-/* R = [k]P */\r
-{\r
-       int j, hj, kj;\r
-       BIGNUM *h;\r
-       EC_POINT *mP;\r
-\r
-       assert(R != NULL);\r
-       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);\r
-\r
-       assert(P != NULL);\r
-       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);\r
-\r
-       assert(E != NULL);\r
-       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);\r
-\r
-       assert(k != NULL);\r
-       assert(!k->neg);\r
-\r
-       assert(ctx != NULL);\r
-\r
-       assert(mont != NULL);\r
-       assert(mont->p != NULL);\r
-\r
-       if (!E->is_in_mont) \r
-               if (!EC_to_montgomery(E, mont, ctx)) return 0;\r
-\r
-       if (!P->is_in_mont) \r
-               if (!ECP_to_montgomery(P, mont, ctx)) return 0;\r
-\r
-\r
-       if (BN_is_zero(k))\r
-       {\r
-               if (!BN_zero(R->Z)) return 0;\r
-               R->is_in_mont = 1;\r
-               return 1;\r
-       }\r
-\r
-       if ((h = BN_dup(k)) == NULL) return 0;\r
-       \r
-       if (!BN_lshift1(h, h)) goto err;\r
-       if (!BN_add(h, h, k)) goto err;\r
-\r
-       if (!ECP_copy(R, P)) goto err;\r
-       if ((mP = ECP_mont_minus(P, mont)) == NULL) goto err;\r
-\r
-       for(j = BN_num_bits(h) - 2; j > 0; j--)\r
-       {\r
-               if (!ECP_mont_double(R, R, E, mont, ctx)) goto err;\r
-               kj = BN_is_bit_set(k, j);\r
-               hj = BN_is_bit_set(h, j);\r
-               if (hj == 1 && kj == 0)\r
-                       if (!ECP_mont_add(R, R, P, E, mont, ctx)) goto err;\r
-               if (hj == 0 && kj == 1)\r
-                       if (!ECP_mont_add(R, R, mP, E, mont, ctx)) goto err;\r
-       }\r
-\r
-       if (h != NULL) BN_free(h);\r
-       if (mP != NULL) ECP_clear_free(mP);\r
-       return 1;\r
-\r
-err:\r
-       if (h != NULL) BN_free(h);\r
-       if (mP != NULL) ECP_clear_free(mP);\r
-       return 0;\r
-}\r
-\r
-#endif /* MONTGOMERY */\r
+/*
+ *
+ *     ec_point.c
+ *
+ *     Elliptic Curve Arithmetic Functions
+ *
+ *     Copyright (C) Lenka Fibikova 2000
+ *
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <memory.h>
+
+#include "bn.h"
+
+#include "bn_modfs.h"
+#include "bn_mont2.h"
+#include "ec.h"
+
+EC_POINT *ECP_new()
+{
+       EC_POINT *ret;
+
+       ret=(EC_POINT *)malloc(sizeof(EC_POINT));
+       if (ret == NULL) return NULL;
+       ret->X = BN_new();
+       ret->Y = BN_new();
+       ret->Z = BN_new();
+       ret->is_in_mont = 0;
+
+       if (ret->X == NULL || ret->Y == NULL || ret->Z == NULL) 
+       {
+               if (ret->X != NULL) BN_free(ret->X);
+               if (ret->Y != NULL) BN_free(ret->Y);
+               if (ret->Z != NULL) BN_free(ret->Z);
+               free(ret);
+               return(NULL);
+       }
+       return(ret);
+}
+
+void ECP_clear_free(EC_POINT *P)
+{
+       if (P == NULL) return;
+       
+       P->is_in_mont = 0;
+       if (P->X != NULL) BN_clear_free(P->X);
+       if (P->Y != NULL) BN_clear_free(P->Y);
+       if (P->Z != NULL) BN_clear_free(P->Z);
+       free(P);
+}
+
+void ECP_clear_free_precompute(ECP_PRECOMPUTE *prec)
+{
+       int i;
+       int max;
+
+       if (prec == NULL) return;
+       if (prec->Pi != NULL)
+       {
+               max = 1;
+               max <<= (prec->r - 1);
+
+               for (i = 0; i < max; i++)
+               {
+                       if (prec->Pi[i] != NULL) ECP_clear_free(prec->Pi[i]);
+               }
+       }
+       free(prec);
+}
+
+int ECP_is_on_ec(EC_POINT *P, EC *E, BN_CTX *ctx)
+{
+       BIGNUM *n0, *n1, *n2, *p;
+       int Pnorm;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL);
+
+       assert(ctx != NULL);
+
+       assert(!P->is_in_mont);
+
+       if (ECP_is_infty(P)) return 1;
+       
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       ctx->tos += 3;
+
+
+       p = E->p;
+
+       Pnorm = (ECP_is_norm(P));
+
+       if (!Pnorm)
+       {
+               if (!BN_mod_mul(n0, P->Z, P->Z, p, ctx)) goto err;
+               if (!BN_mod_mul(n1, n0, n0, p, ctx)) goto err;
+               if (!BN_mod_mul(n2, n0, n1, p, ctx)) goto err;
+       }
+
+       if (!BN_mod_mul(n0, P->X, P->X, p, ctx)) goto err;
+       if (!BN_mod_mul(n0, n0, P->X, p, ctx)) goto err;
+
+       if (Pnorm)
+       {
+               if (!BN_mod_mul(n1, P->X, E->A, p, ctx)) goto err;
+       }
+       else
+       {
+               if (!BN_mod_mul(n1, n1, P->X, p, ctx)) goto err;
+               if (!BN_mod_mul(n1, n1, E->A, p, ctx)) goto err;
+       }
+       if (!BN_mod_add(n0, n0, n1, p, ctx)) goto err;
+
+       if (Pnorm)
+       {
+               if (!BN_mod_add(n0, n0, E->B, p, ctx)) goto err;
+       }
+       else
+       {
+               if (!BN_mod_mul(n2, n2, E->B,  p, ctx)) goto err;
+               if (!BN_mod_add(n0, n0, n2, p, ctx)) goto err;
+       }
+
+       if (!BN_mod_mul(n1, P->Y, P->Y, p, ctx)) goto err;
+
+       if (BN_cmp(n0, n1)) 
+       { 
+               ctx->tos -= 3;
+               return 0;
+       }
+
+       ctx->tos -= 3;
+       return 1;
+       
+err:
+       ctx->tos -= 3;
+       return -1;
+}
+
+
+EC_POINT *ECP_generate(BIGNUM *x, BIGNUM *z,EC *E, BN_CTX *ctx)
+/* x == NULL || z = 0  -> point of infinity    */
+/* z == NULL || z = 1  -> normalized           */
+{
+       BIGNUM *n0, *n1;
+       EC_POINT *ret;
+       int Pnorm, Pinfty, X0, A0;
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(ctx != NULL);
+
+       Pinfty = (x == NULL);
+       Pnorm = (z == NULL);
+       if (!Pnorm) 
+       {
+               Pnorm = BN_is_one(z);
+               Pinfty = (Pinfty || BN_is_zero(z));
+       }
+
+       if (Pinfty) 
+       {
+               if ((ret = ECP_new()) == NULL) return NULL;
+               if (!BN_zero(ret->Z)) 
+               { 
+                       ECP_clear_free(ret);
+                       return NULL;
+               }
+               return ret;
+       }
+
+       X0 = BN_is_zero(x);
+       A0 = BN_is_zero(E->A);
+
+       if ((ret = ECP_new()) == NULL) return NULL;
+
+       ret->is_in_mont = 0;
+
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       if (!BN_zero(n0)) return NULL;
+       if (!BN_zero(n1)) return NULL;
+
+       ctx->tos += 2;
+
+       if (!X0)
+       {
+               if (!BN_mod_sqr(n0, x, E->p, ctx)) goto err;
+               if (!BN_mod_mul(n0, n0, x, E->p, ctx)) goto err;        /* x^3 */
+       }
+
+       if (!X0 && !A0)
+       {
+               if (!BN_mod_mul(n1, E->A, x, E->p, ctx)) goto err;      /* Ax */
+               if (!BN_mod_add(n0, n0, n1, E->p, ctx)) goto err;       /* x^3 + Ax */
+       }
+
+       if (!BN_is_zero(E->B))
+               if (!BN_mod_add(n0, n0, E->B, E->p, ctx)) goto err;     /* x^3 + Ax +B */
+
+       if (!BN_mod_sqrt(ret->Y, n0, E->p, ctx)) goto err;
+       if (BN_copy(ret->X, x) == NULL) goto err;
+       
+       if (Pnorm)
+       {
+               if (!BN_one(ret->Z)) goto err;
+       }
+       else
+       {
+               if (BN_copy(ret->Z, z) == NULL) goto err;
+               if (!BN_mod_sqr(n0, z, E->p, ctx)) goto err;
+               if (!BN_mod_mul(ret->X, ret->X, n0, E->p, ctx)) goto err;
+               if (!BN_mod_mul(n0, n0, z, E->p, ctx)) goto err;
+               if (!BN_mod_mul(ret->Y, ret->Y, n0, E->p, ctx)) goto err;
+       }
+
+#ifdef TEST
+       if (!ECP_is_on_ec(ret, E, ctx)) goto err;
+#endif
+       
+       ctx->tos -= 2;
+       return ret;
+
+err:
+       if (ret != NULL) ECP_clear_free(ret);
+       ctx->tos -= 2;
+       return NULL;
+}
+
+int ECP_ecp2bin(EC_POINT *P, unsigned char *to, int form)
+/* form =      1 ... compressed
+                       2 ... uncompressed
+                       3 ... hybrid */
+{
+       int bytes, bx, by;
+
+       assert (P != NULL);
+       assert (P->X != NULL && P->Y != NULL && P->Z != NULL);
+       assert (!P->is_in_mont);
+       assert (ECP_is_norm(P) || ECP_is_infty(P));
+       assert (to != NULL);
+       assert (form > 0 && form < 4);
+
+       if (BN_is_zero(P->Z))
+       {
+               to[0] = 0;
+               return 1;
+       }
+
+       bx = BN_num_bytes(P->X);
+       if (form == 1 ) bytes = bx + 1;
+       else 
+       {
+               by = BN_num_bytes(P->Y);
+               bytes = (bx > by ? bx : by);
+               bytes = bytes * 2 + 1;
+       }
+       memset(to, 0, bytes);
+
+       switch (form)
+       {
+       case 1: to[0] = 2;      break;
+       case 2: to[0] = 4;      break;
+       case 3: to[0] = 6;      break;
+       }
+       if (form != 2) to[0] += BN_is_bit_set(P->Y, 0);
+
+       
+       if ((BN_bn2bin(P->X, to + 1)) != bx) return 0;
+       if (form != 1)
+       {
+               if ((BN_bn2bin(P->Y, to + bx + 1)) != by) return 0;
+       }
+
+       return bytes;
+}
+
+int ECP_bin2ecp(unsigned char *from, int len, EC_POINT *P, EC *E, BN_CTX *ctx)
+{
+       int y;
+       BIGNUM *x;
+       EC_POINT *pp;
+
+       assert (E != NULL);
+       assert (E->A != NULL && E->B != NULL && E->p != NULL);
+       assert (!E->is_in_mont);
+
+       assert (ctx != NULL);
+       assert (from != NULL);
+       assert (P != NULL);
+       assert (P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       if (len == 1 && from[0] != 0) return 0;
+
+       if (len == 0 || len == 1)
+       { 
+               if (!BN_zero(P->Z)) return 0;
+               return 1;
+       }
+
+       switch (from[0])
+       {
+       case 2:
+       case 3:
+               y = from[0] - 2;
+               if ((x = BN_new()) == NULL) return 0;
+               if (BN_bin2bn(from + 1, len - 1, x) == NULL) return 0;
+
+               pp = ECP_generate(x, NULL, E, ctx);
+               BN_clear_free(x);
+               if (pp == NULL) return 0;
+
+               ECP_copy(P, pp);
+               ECP_clear_free(pp);
+
+               if (BN_is_bit_set(P->Y, 0) != y)
+                       if (!BN_sub(P->Y, E->p, P->Y)) return 0;
+               break;
+
+       case 4:
+       case 6:
+       case 7:
+               y = (len - 1)/2;
+               if (BN_bin2bn(from + 1, y, P->X) == NULL) return 0;
+               if (BN_bin2bn(from + y + 1, y, P->Y) == NULL) return 0;
+               if (!BN_set_word(P->Z, 1)) return 0;
+               break;
+
+       default:
+               assert(0);
+
+       }
+
+       if (!ECP_is_on_ec(P, E, ctx)) return 0;
+       return 1;
+}
+
+int ECP_normalize(EC_POINT *P, EC *E, BN_CTX *ctx)
+{
+       BIGNUM *z, *zm;
+
+       assert (P != NULL);
+       assert (P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert (E != NULL);
+       assert (E->A != NULL && E->B != NULL && E->p != NULL);
+
+       assert (ctx != NULL);
+
+       if (ECP_is_norm(P)) return 1;
+       if (ECP_is_infty(P)) return 0;
+
+       if ((zm = BN_mod_inverse(P->Z, E->p, ctx)) == NULL) return 0;
+
+       assert(!P->is_in_mont);
+
+
+       z = ctx->bn[ctx->tos]; 
+       ctx->tos++;
+
+       if (!BN_mod_mul(z, zm, zm, E->p, ctx)) goto err;
+       if (!BN_mod_mul(P->X, P->X, z, E->p, ctx)) goto err;
+
+       if (!BN_mod_mul(z, z, zm, E->p, ctx)) goto err;
+       if (!BN_mod_mul(P->Y, P->Y, z, E->p, ctx)) goto err;
+
+       if (!BN_one(P->Z)) goto err;
+
+       if (zm != NULL) BN_clear_free(zm);
+
+       ctx->tos--;
+       return 1;
+
+err:
+       if (zm != NULL) BN_clear_free(zm);
+       ctx->tos--;
+       return 0;
+}
+
+int ECP_copy(EC_POINT *R, EC_POINT *P)
+{
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       if (BN_copy(R->X, P->X) == NULL) return 0;
+       if (BN_copy(R->Y, P->Y) == NULL) return 0;
+       if (BN_copy(R->Z, P->Z) == NULL) return 0;
+       R->is_in_mont = P->is_in_mont;
+
+       return 1;
+}
+
+EC_POINT *ECP_dup(EC_POINT *P)
+{
+       EC_POINT *ret;
+
+       ret = ECP_new();
+       if (ret == NULL) return NULL;
+
+       if (!ECP_copy(ret, P))
+       {
+               ECP_clear_free(ret);
+               return(NULL);
+       }
+
+       return(ret);
+}
+
+
+EC_POINT *ECP_minus(EC_POINT *P, BIGNUM *p) /* mont || non-mont */
+{
+       EC_POINT *ret;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(p != NULL);
+
+       assert(BN_cmp(P->Y, p) < 0);
+
+       ret = ECP_dup(P);
+       if (ret == NULL) return NULL;
+
+       if (BN_is_zero(ret->Y)) return ret;
+
+       if (!BN_sub(ret->Y, p, ret->Y))
+       {
+               ECP_clear_free(ret);
+               return NULL;
+       }
+
+       return ret;
+}
+
+
+#ifdef SIMPLE
+int ECP_cmp(EC_POINT *P, EC_POINT *Q, BIGNUM *p, BN_CTX *ctx)
+/* return values: 
+       -2 ... error
+        0 ... P = Q 
+       -1 ... P = -Q
+        1 ... else
+*/
+{
+       BIGNUM *n0, *n1, *n2, *n3, *n4;
+       int Pnorm, Qnorm;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(Q != NULL);
+       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
+
+       assert(p != NULL);
+       assert(ctx != NULL);
+
+       assert(!P->is_in_mont);
+       assert(!Q->is_in_mont);
+
+       if (ECP_is_infty(P) && ECP_is_infty(Q)) return 0;
+       if (ECP_is_infty(P) || ECP_is_infty(Q)) return 1;
+
+       
+       Pnorm = (ECP_is_norm(P));
+       Qnorm = (ECP_is_norm(Q));
+       
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       n3 = ctx->bn[ctx->tos + 3]; 
+       n4 = ctx->bn[ctx->tos + 4]; 
+       ctx->tos += 5;
+       
+       if (Qnorm)
+       {
+               if (BN_copy(n1, P->X) == NULL) goto err;                        /* L1 = x_p */
+               if (BN_copy(n2, P->Y) == NULL) goto err;                        /* L2 = y_p */
+       }
+       else
+       {
+               if (!BN_sqr(n0, Q->Z, ctx)) goto err;
+               if (!BN_mod_mul(n1, P->X, n0, p, ctx)) goto err;        /* L1 = x_p * z_q^2 */
+
+               if (!BN_mod_mul(n0, n0, Q->Z, p, ctx)) goto err; 
+               if (!BN_mod_mul(n2, P->Y, n0, p, ctx)) goto err;        /* L2 = y_p * z_q^3 */
+       }
+
+       if (Pnorm)
+       {
+               if (BN_copy(n3, Q->X) == NULL) goto err;                        /* L3 = x_q */
+               if (BN_copy(n4, Q->Y) == NULL) goto err;                        /* L4 = y_q */
+       }
+       else
+       {
+               if (!BN_sqr(n0, P->Z, ctx)) goto err;
+               if (!BN_mod_mul(n3, Q->X, n0, p, ctx)) goto err;        /* L3 = x_q * z_p^2 */
+
+               if (!BN_mod_mul(n0, n0, P->Z, p, ctx)) goto err; 
+               if (!BN_mod_mul(n4, Q->Y, n0, p, ctx)) goto err;        /* L4 = y_q * z_p^3 */
+       }
+
+       if (!BN_mod_sub(n0, n1, n3, p, ctx)) goto err;                  /* L5 = L1 - L3 */
+
+       if (!BN_is_zero(n0))
+       {
+               ctx->tos -= 5;
+               return 1;
+       }
+       
+       if (!BN_mod_sub(n0, n2, n4, p, ctx)) goto err;                  /* L6 = L2 - L4 */
+
+       if (!BN_is_zero(n0))
+       {
+               ctx->tos -= 5;
+               return -1;
+       }
+
+       ctx->tos -= 5;
+       return 0;
+
+err:
+       ctx->tos -= 5;
+       return -2;
+}
+
+int ECP_double(EC_POINT *R, EC_POINT *P, EC *E, BN_CTX *ctx)
+/* R <- 2P (on E) */
+{
+       BIGNUM *n0, *n1, *n2, *n3, *p;
+       int Pnorm, A0;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(ctx != NULL);
+
+       assert(!P->is_in_mont);
+
+       if (ECP_is_infty(P))
+       {
+               if (!BN_zero(R->Z)) return 0;
+               return 1;
+       }
+
+       Pnorm = (ECP_is_norm(P));
+       A0 = (BN_is_zero(E->A));
+
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       n3 = ctx->bn[ctx->tos + 3]; 
+       ctx->tos += 4;
+
+       p = E->p;
+
+       /* L1 */
+       if (Pnorm || A0)
+       {
+               if (!BN_mod_sqr(n1, P->X, p, ctx)) goto err;
+               if (!BN_mul_word(n1, 3)) goto err;  
+               if (!A0)                                   /* if A = 0: L1 = 3 * x^2 + a * z^4 = 3 * x ^2    */
+                       if (!BN_mod_add(n1, n1, E->A, p, ctx)) goto err; /* L1 = 3 * x^2 + a * z^4 = 3 * x^2 + a */
+       }
+       else
+       {
+               if (!BN_mod_sqr(n0, P->Z, p, ctx)) goto err;
+               if (!BN_mod_mul(n0, n0, n0, p, ctx)) goto err;
+               if (!BN_mod_mul(n0, n0, E->A, p, ctx)) goto err; 
+               if (!BN_mod_sqr(n1, P->X, p, ctx)) goto err;
+               if (!BN_mul_word(n1, 3)) goto err;  
+               if (!BN_mod_add(n1, n1, n0, p, ctx)) goto err;          /* L1 = 3 * x^2 + a * z^4 */
+       }
+
+       /* Z */
+       if (Pnorm)
+       {
+               if (BN_copy(n0, P->Y) == NULL) goto err;
+       }
+       else
+       {
+               if (!BN_mod_mul(n0, P->Y, P->Z, p, ctx)) goto err; 
+       }
+       if (!BN_lshift1(n0, n0)) goto err; 
+       if (!BN_smod(R->Z, n0, p, ctx)) goto err;                               /* Z = 2 * y * z */
+
+       /* L2 */
+       if (!BN_mod_sqr(n3, P->Y, p, ctx)) goto err;
+       if (!BN_mod_mul(n2, P->X, n3, p, ctx)) goto err; 
+       if (!BN_lshift(n2, n2, 2)) goto err; 
+       if (!BN_smod(n2, n2, p, ctx)) goto err;                                 /* L2 = 4 * x * y^2 */
+
+       /* X */
+       if (!BN_lshift1(n0, n2)) goto err; 
+       if (!BN_mod_sqr(R->X, n1, p, ctx)) goto err;
+       if (!BN_mod_sub(R->X, R->X, n0, p, ctx)) goto err;              /* X = L1^2 - 2 * L2 */
+       
+       /* L3 */
+       if (!BN_mod_sqr(n0, n3, p, ctx)) goto err;
+       if (!BN_lshift(n3, n0, 3)) goto err; 
+       if (!BN_smod(n3, n3, p, ctx)) goto err;                                 /* L3 = 8 * y^4 */
+       
+       /* Y */
+       if (!BN_mod_sub(n0, n2, R->X, p, ctx)) goto err; 
+       if (!BN_mod_mul(n0, n1, n0, p, ctx)) goto err; 
+       if (!BN_mod_sub(R->Y, n0, n3, p, ctx)) goto err;                /* Y = L1 * (L2 - X) - L3 */
+
+
+#ifdef TEST
+       if (!ECP_is_on_ec(R, E, ctx)) return 0;
+#endif
+
+       ctx->tos -= 4;
+       return 1;
+
+err:
+       ctx->tos -= 4;
+       return 0;
+}
+
+int ECP_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_CTX *ctx)
+/* R <- P + Q (on E) */
+{
+       BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6, *p;
+       int Pnorm, Qnorm;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(Q != NULL);
+       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+       assert(!BN_is_zero(E->h));;
+
+       assert(ctx != NULL);
+
+       assert(!P->is_in_mont);
+       assert(!Q->is_in_mont);
+
+       if (P == Q) return ECP_double(R, P, E, ctx);
+
+       if (ECP_is_infty(P)) return ECP_copy(R, Q);
+       if (ECP_is_infty(Q)) return ECP_copy(R, P);
+       
+       Pnorm = (ECP_is_norm(P));
+       Qnorm = (ECP_is_norm(Q));
+       
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       n3 = ctx->bn[ctx->tos + 3]; 
+       n4 = ctx->bn[ctx->tos + 4]; 
+       n5 = ctx->bn[ctx->tos + 5]; 
+       n6 = ctx->bn[ctx->tos + 6]; 
+       ctx->tos += 7;
+       p = E->p;
+       
+       /* L1; L2 */
+       if (Qnorm)
+       {
+               if (BN_copy(n1, P->X) == NULL) goto err;         /* L1 = x_p */
+               if (BN_copy(n2, P->Y) == NULL) goto err;         /* L2 = y_p */
+       }
+       else
+       {
+               if (!BN_sqr(n0, Q->Z, ctx)) goto err;
+               if (!BN_mod_mul(n1, P->X, n0, p, ctx)) goto err; /* L1 = x_p * z_q^2 */
+
+               if (!BN_mod_mul(n0, n0, Q->Z, p, ctx)) goto err; 
+               if (!BN_mod_mul(n2, P->Y, n0, p, ctx)) goto err; /* L2 = y_p * z_q^3 */
+       }
+
+       /* L3; L4 */
+       if (Pnorm)
+       {
+               if (BN_copy(n3, Q->X) == NULL) goto err;         /* L3 = x_q */
+               if (BN_copy(n4, Q->Y) == NULL) goto err;         /* L4 = y_q */
+       }
+       else
+       {
+               if (!BN_sqr(n0, P->Z, ctx)) goto err;
+               if (!BN_mod_mul(n3, Q->X, n0, p, ctx)) goto err; /* L3 = x_q * z_p^2 */
+
+               if (!BN_mod_mul(n0, n0, P->Z, p, ctx)) goto err; 
+               if (!BN_mod_mul(n4, Q->Y, n0, p, ctx)) goto err; /* L4 = y_q * z_p^3 */
+       }
+
+       /* L5; L6 */
+       if (!BN_mod_sub(n5, n1, n3, p, ctx)) goto err;          /* L5 = L1 - L3 */
+       if (!BN_mod_sub(n6, n2, n4, p, ctx)) goto err;          /* L6 = L2 - L4 */
+
+       /* pata */
+       if (BN_is_zero(n5))
+       {
+               if (BN_is_zero(n6))     /* P = Q => P + Q = 2P */
+               {
+                       ctx->tos -= 7;
+                       return ECP_double(R, P, E, ctx);
+               }
+               else                             /* P = -Q => P + Q = \infty */
+               { 
+                       ctx->tos -= 7;
+                       if (!BN_zero(R->Z)) return 0;
+                       return 1;
+               }
+       }
+
+       /* L7; L8 */
+       if (!BN_mod_add(n1, n1, n3, p, ctx)) goto err;          /* L7 = L1 + L3 */
+       if (!BN_mod_add(n2, n2, n4, p, ctx)) goto err;          /* L8 = L2 + L4 */
+
+       /* Z */
+       if (Pnorm) 
+       {
+               if (BN_copy(n0, Q->Z) == NULL) goto err;
+       }
+       else
+       {
+               if (!BN_mod_mul(n0, P->Z, Q->Z, p, ctx)) goto err;
+       }
+       if (!BN_mod_mul(R->Z, n0, n5, p, ctx)) goto err;        /* Z = z_p * z_q * L_5 */
+
+       /* X */
+       if (!BN_mod_sqr(n0, n6, p, ctx)) goto err;
+       if (!BN_mod_sqr(n4, n5, p, ctx)) goto err;
+       if (!BN_mod_mul(n3, n1, n4, p, ctx)) goto err; 
+       if (!BN_mod_sub(R->X, n0, n3, p, ctx)) goto err;        /* X = L6^2 - L5^2 * L7 */
+       
+       /* L9 */
+       if (!BN_lshift1(n0, R->X)) goto err;
+       if (!BN_mod_sub(n0, n3, n0, p, ctx)) goto err;          /* L9 = L5^2 * L7 - 2X */
+
+       /* Y */
+       if (!BN_mod_mul(n0, n0, n6, p, ctx)) goto err; 
+       if (!BN_mod_mul(n5, n4, n5, p, ctx)) goto err; 
+       if (!BN_mod_mul(n1, n2, n5, p, ctx)) goto err; 
+       if (!BN_mod_sub(n0, n0, n1, p, ctx)) goto err;   
+       if (!BN_mod_mul(R->Y, n0, E->h, p, ctx)) goto err;      /* Y = (L6 * L9 - L8 * L5^3) / 2 */
+
+
+
+#ifdef TEST
+       if (!ECP_is_on_ec(R, E, ctx)) return 0;
+#endif
+
+       ctx->tos -= 7;
+       return 1;
+
+err:
+       ctx->tos -= 7;
+       return 0;
+}
+
+
+ECP_PRECOMPUTE *ECP_precompute(int r, EC_POINT *P, EC *E, BN_CTX *ctx)
+{
+       ECP_PRECOMPUTE *ret;
+       EC_POINT *P2;
+       int i, max;
+
+       assert(r > 2);
+       assert(!P->is_in_mont);
+       assert(!E->is_in_mont);
+
+       ret=(ECP_PRECOMPUTE *)malloc(sizeof(ECP_PRECOMPUTE));
+       if (ret == NULL) return NULL;
+
+       max = 1;
+       max <<= (r - 1);
+
+       ret->r = 0;
+
+       ret->Pi=(EC_POINT **)malloc(sizeof(EC_POINT *) * max);
+       if (ret->Pi == NULL) goto err;
+
+       
+       /* P2 = [2]P */
+       if ((P2 = ECP_new()) == NULL) goto err;
+       if (!ECP_double(P2, P, E, ctx)) goto err;
+
+       /* P_0 = P */
+       if((ret->Pi[0] = ECP_dup(P)) == NULL) goto err;
+
+
+       /* P_i = P_(i-1) + P2 */
+       for (i = 1; i < max; i++)
+       {
+               if ((ret->Pi[i] = ECP_new()) == NULL) goto err;
+               
+               if (!ECP_add(ret->Pi[i], P2, ret->Pi[i - 1], E, ctx)) goto err;
+       }
+
+       ret->r = r;
+       ECP_clear_free(P2);
+
+       return ret;
+
+err:
+       ECP_clear_free(P2);
+       ECP_clear_free_precompute(ret);
+       return NULL;
+}
+
+int ECP_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_CTX *ctx)
+/* R = [k]P */
+{
+       int j;
+       int t, nextw, h, r;
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(k != NULL);
+       assert(!k->neg);
+
+       assert(ctx != NULL);
+       assert(prec != NULL);
+
+       assert(!E->is_in_mont);
+
+       if (BN_is_zero(k))
+       {
+               if (!BN_zero(R->Z)) return 0;
+               R->is_in_mont = 0;
+               return 1;
+       }
+
+
+       j = BN_num_bits(k);
+       j--;
+
+       r = prec->r;
+
+       if (!BN_zero(R->Z)) return 0;
+       R->is_in_mont = 0;
+
+       while(j >= 0)
+       {
+               if (!BN_is_bit_set(k, j))
+               {
+                       if (!ECP_double(R, R, E, ctx)) return 0;
+                       j--;
+               }
+               else
+               {
+                       nextw = j - r;
+                       if (nextw < -1) nextw = -1;
+                       t = nextw + 1;                  
+                       while(!BN_is_bit_set(k, t))
+                       {
+                               t++;
+                       }
+
+                       if (!ECP_double(R, R, E, ctx)) return 0;
+
+                       j--;
+                       if (j < t) h = 0;
+                       else 
+                       {
+                               h = 1;
+                               for(; j > t; j--)
+                               {
+                                       h <<= 1;
+                                       if (BN_is_bit_set(k, j)) h++;
+                                       if (!ECP_double(R, R, E, ctx)) return 0;
+                               }
+                               if (!ECP_double(R, R, E, ctx)) return 0;
+                               j--;
+                       }
+
+                       if (!ECP_add(R, R, prec->Pi[h], E, ctx)) return 0;
+
+                       for (; j > nextw; j--)
+                       {
+                               if (!ECP_double(R, R, E, ctx)) return 0;
+                       }
+
+               }
+       }
+
+       return 1;
+}
+
+#endif /* SIMPLE */
+
+#ifdef MONTGOMERY
+
+int ECP_to_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       assert(ctx != NULL);
+
+       if (P->is_in_mont) return 1;
+
+       if (!BN_lshift(P->X, P->X, mont->R_num_bits)) return 0;
+       if (!BN_mod(P->X, P->X, mont->p, ctx)) return 0;
+
+       if (!BN_lshift(P->Y, P->Y, mont->R_num_bits)) return 0;
+       if (!BN_mod(P->Y, P->Y, mont->p, ctx)) return 0;
+
+       if (!BN_lshift(P->Z, P->Z, mont->R_num_bits)) return 0;
+       if (!BN_mod(P->Z, P->Z, mont->p, ctx)) return 0;
+
+       P->is_in_mont = 1;
+       return 1;
+}
+
+
+int ECP_from_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       assert(ctx != NULL);
+
+       if (!P->is_in_mont) return 1;
+
+       if (!BN_mont_red(P->X, mont, ctx)) return 0;
+       if (!BN_mont_red(P->Y, mont, ctx)) return 0;
+       if (!BN_mont_red(P->Z, mont, ctx)) return 0;
+
+       P->is_in_mont = 0;
+       return 1;
+}
+
+int ECP_mont_cmp(EC_POINT *P, EC_POINT *Q, BN_MONTGOMERY *mont, BN_CTX *ctx) 
+/* return values: 
+       -2 ... error
+        0 ... P = Q 
+       -1 ... P = -Q
+        1 ... else
+*/
+{
+       BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *p;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(Q != NULL);
+       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       assert(ctx != NULL);
+
+       if (!P->is_in_mont)
+               if (!ECP_to_montgomery(P, mont, ctx)) return 0;
+
+       if (!Q->is_in_mont)
+               if (!ECP_to_montgomery(Q, mont, ctx)) return 0;
+
+
+       if (ECP_is_infty(P) && ECP_is_infty(Q)) return 0;
+       if (ECP_is_infty(P) || ECP_is_infty(Q)) return 1;
+
+       
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       n3 = ctx->bn[ctx->tos + 3]; 
+       n4 = ctx->bn[ctx->tos + 4]; 
+       n5 = ctx->bn[ctx->tos + 5]; 
+       ctx->tos += 6;
+
+       p = mont->p;
+       
+
+       if (!BN_mont_mod_mul(n5, Q->Z, Q->Z, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n1, P->X, n5, mont, ctx)) goto err;        /* L1 = x_p * z_q^2 */
+
+       if (!BN_mont_mod_mul(n0, n5, Q->Z, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n2, P->Y, n0, mont, ctx)) goto err;        /* L2 = y_p * z_q^3 */
+
+       if (!BN_mont_mod_mul(n5, P->Z, P->Z, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n3, Q->X, n5, mont, ctx)) goto err;        /* L3 = x_q * z_p^2 */
+
+       if (!BN_mont_mod_mul(n0, n5, P->Z, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n4, Q->Y, n0, mont, ctx)) goto err;        /* L4 = y_q * z_p^3 */
+
+
+       if (!BN_mont_mod_sub(n0, n1, n3, mont)) goto err;                       /* L5 = L1 - L3 */
+
+       if (!BN_is_zero(n0))
+       {
+               ctx->tos -= 6;
+               return 1;
+       }
+       
+       if (!BN_mont_mod_sub(n0, n2, n4, mont)) goto err;                       /* L6 = L2 - L4 */
+
+       if (!BN_is_zero(n0))
+       {
+               ctx->tos -= 6;
+               return -1;
+       }
+
+       ctx->tos -= 6;
+       return 0;
+
+err:
+       ctx->tos -= 6;
+       return -2;
+}
+
+
+int ECP_mont_double(EC_POINT *R, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+/* R <- 2P (on E) */
+{
+       BIGNUM *n0, *n1, *n2, *n3, *p;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(ctx != NULL);
+       
+       if (!P->is_in_mont)
+               if (!ECP_to_montgomery(P, mont, ctx)) return 0;
+
+       if (!E->is_in_mont) 
+               if (!EC_to_montgomery(E, mont, ctx)) return 0;
+
+       R->is_in_mont = 1;
+
+       if (ECP_is_infty(P))
+       {
+               if (!BN_zero(R->Z)) return 0;
+               return 1;
+       }
+
+
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       n3 = ctx->bn[ctx->tos + 3]; 
+
+       ctx->tos += 4;
+
+       p = E->p;
+
+       /* L1 */
+       if (!BN_mont_mod_mul(n0, P->Z, P->Z, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n2, n0, n0, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n0, n2, E->A, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n1, P->X, P->X, mont, ctx)) goto err;
+       if (!BN_mont_mod_lshift1(n2, n1, mont)) goto err;
+       if (!BN_mont_mod_add(n1, n1, n2, mont)) goto err;
+       if (!BN_mont_mod_add(n1, n1, n0, mont)) goto err;               /* L1 = 3 * x^2 + a * z^4 */
+
+       /* Z */
+       if (!BN_mont_mod_mul(n0, P->Y, P->Z, mont, ctx)) goto err; 
+       if (!BN_mont_mod_lshift1(R->Z, n0, mont)) goto err;             /* Z = 2 * y * z */
+
+       /* L2 */
+       if (!BN_mont_mod_mul(n3, P->Y, P->Y, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n2, P->X, n3, mont, ctx)) goto err; 
+       if (!BN_mont_mod_lshift(n2, n2, 2, mont)) goto err;             /* L2 = 4 * x * y^2 */
+
+       /* X */
+       if (!BN_mont_mod_lshift1(n0, n2, mont)) goto err; 
+       if (!BN_mont_mod_mul(R->X, n1, n1, mont, ctx)) goto err;
+       if (!BN_mont_mod_sub(R->X, R->X, n0, mont)) goto err;   /* X = L1^2 - 2 * L2 */
+       
+       /* L3 */
+       if (!BN_mont_mod_mul(n0, n3, n3, mont, ctx)) goto err;
+       if (!BN_mont_mod_lshift(n3, n0, 3, mont)) goto err;             /* L3 = 8 * y^4 */
+
+       
+       /* Y */
+       if (!BN_mont_mod_sub(n2, n2, R->X, mont)) goto err; 
+       if (!BN_mont_mod_mul(n0, n1, n2, mont, ctx)) goto err; 
+       if (!BN_mont_mod_sub(R->Y, n0, n3, mont)) goto err;             /* Y = L1 * (L2 - X) - L3 */
+
+       ctx->tos -= 4;
+       return 1;
+
+err:
+       ctx->tos -= 4;
+       return 0;
+}
+
+
+int ECP_mont_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+/* R <- P + Q (on E) */
+{
+       BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6, *p;
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(Q != NULL);
+       assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+       assert(!BN_is_zero(E->h));;
+
+       assert(ctx != NULL);
+
+       if (!Q->is_in_mont)
+               if (!ECP_to_montgomery(Q, mont, ctx)) return 0;
+
+       if (!P->is_in_mont)
+               if (!ECP_to_montgomery(P, mont, ctx)) return 0;
+
+       if (!E->is_in_mont) 
+               if (!EC_to_montgomery(E, mont, ctx)) return 0;
+
+       if (P == Q) return ECP_mont_double(R, P, E, mont, ctx);
+
+       if (ECP_is_infty(P)) return ECP_copy(R, Q);
+       if (ECP_is_infty(Q)) return ECP_copy(R, P);
+       
+
+       n0 = ctx->bn[ctx->tos]; 
+       n1 = ctx->bn[ctx->tos + 1]; 
+       n2 = ctx->bn[ctx->tos + 2]; 
+       n3 = ctx->bn[ctx->tos + 3]; 
+       n4 = ctx->bn[ctx->tos + 4]; 
+       n5 = ctx->bn[ctx->tos + 5]; 
+       n6 = ctx->bn[ctx->tos + 6]; 
+       ctx->tos += 7;
+
+
+       p = E->p;
+
+       R->is_in_mont = 1;
+       
+       /* L1; L2 */
+       if (!BN_mont_mod_mul(n6, Q->Z, Q->Z, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n1, P->X, n6, mont, ctx)) goto err;        /* L1 = x_p * z_q^2 */
+
+       if (!BN_mont_mod_mul(n0, n6, Q->Z, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n2, P->Y, n0, mont, ctx)) goto err;        /* L2 = y_p * z_q^3 */
+
+
+       /* L3; L4 */
+       if (!BN_mont_mod_mul(n6, P->Z, P->Z, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n3, Q->X, n6, mont, ctx)) goto err;        /* L3 = x_q * z_p^2 */
+
+       if (!BN_mont_mod_mul(n0, n6, P->Z, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n4, Q->Y, n0, mont, ctx)) goto err;        /* L4 = y_q * z_p^3 */
+
+
+       /* L5; L6 */
+       if (!BN_mont_mod_sub(n5, n1, n3, mont)) goto err;                       /* L5 = L1 - L3 */
+       if (!BN_mont_mod_sub(n6, n2, n4, mont)) goto err;                       /*L6 = L2 - L4 */
+
+
+       /* pata */
+       if (BN_is_zero(n5))
+       {
+               if (BN_is_zero(n6))  /* P = Q => P + Q = 2P */
+               {
+                       ctx->tos -= 7;
+                       return ECP_mont_double(R, P, E, mont, ctx);
+               }
+               else                             /* P = -Q => P + Q = \infty */
+               { 
+                       ctx->tos -= 7;
+                       if (!BN_zero(R->Z)) return 0;
+                       return 1;
+               }
+       }
+
+       /* L7; L8 */
+       if (!BN_mont_mod_add(n1, n1, n3, mont)) goto err;                       /* L7 = L1 + L3 */
+       if (!BN_mont_mod_add(n2, n2, n4, mont)) goto err;                       /* L8 = L2 + L4 */
+
+
+       /* Z */
+       if (!BN_mont_mod_mul(n0, P->Z, Q->Z, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(R->Z, n0, n5, mont, ctx)) goto err;        /* Z = z_p * z_q * L_5 */
+
+
+       /* X */
+       if (!BN_mont_mod_mul(n0, n6, n6, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n4, n5, n5, mont, ctx)) goto err;
+       if (!BN_mont_mod_mul(n3, n1, n4, mont, ctx)) goto err; 
+       if (!BN_mont_mod_sub(R->X, n0, n3, mont)) goto err;                     /* X = L6^2 - L5^2 * L7 */
+
+       
+       /* L9 */
+       if (!BN_mont_mod_lshift1(n0, R->X, mont)) goto err;
+       if (!BN_mont_mod_sub(n3, n3, n0, mont)) goto err;                       /* L9 = L5^2 * L7 - 2X */
+
+
+       /* Y */
+       if (!BN_mont_mod_mul(n0, n3, n6, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n6, n4, n5, mont, ctx)) goto err; 
+       if (!BN_mont_mod_mul(n1, n2, n6, mont, ctx)) goto err; 
+       if (!BN_mont_mod_sub(n0, n0, n1, mont)) goto err;   
+       if (!BN_mont_mod_mul(R->Y, n0, E->h, mont, ctx)) goto err;      /* Y = (L6 * L9 - L8 * L5^3) / 2 */
+
+
+       ctx->tos -= 7;
+       return 1;
+
+err:
+       ctx->tos -= 7;
+       return 0;
+}
+
+
+ECP_PRECOMPUTE *ECP_mont_precompute(int r, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+{
+       ECP_PRECOMPUTE *ret;
+       EC_POINT *P2;
+       int i, max;
+
+       assert(r > 2);
+       assert(r < sizeof(unsigned int) * 8 - 1);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+       
+       if (!P->is_in_mont)
+               if (!ECP_to_montgomery(P, mont, ctx)) return 0;
+
+       if (!E->is_in_mont) 
+               if (!EC_to_montgomery(E, mont, ctx)) return 0;
+
+       ret=(ECP_PRECOMPUTE *)malloc(sizeof(ECP_PRECOMPUTE));
+       if (ret == NULL) return NULL;
+
+       max = 1;
+       max <<= (r - 1);
+
+       ret->r = 0;
+
+       ret->Pi=(EC_POINT **)malloc(sizeof(EC_POINT *) * max);
+       if (ret->Pi == NULL) goto err;
+
+       
+       /* P2 = [2]P */
+       if ((P2 = ECP_new()) == NULL) goto err;
+       if (!ECP_mont_double(P2, P, E, mont, ctx)) goto err;
+
+       /* P_0 = P */
+       if((ret->Pi[0] = ECP_dup(P)) == NULL) goto err;
+
+
+       /* P_i = P_(i-1) + P2 */
+       for (i = 1; i < max; i++)
+       {
+               if ((ret->Pi[i] = ECP_new()) == NULL) goto err;
+               if (!ECP_mont_add(ret->Pi[i], P2, ret->Pi[i - 1], E, mont, ctx)) goto err;
+       }
+
+       ret->r = r;
+       ECP_clear_free(P2);
+
+       return ret;
+
+err:
+       ECP_clear_free(P2);
+       ECP_clear_free_precompute(ret);
+       return NULL;
+}
+
+int ECP_mont_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+/* R = [k]P   P = prec->Pi[0]*/
+{
+       int j;
+       int t, nextw, h, r;
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(k != NULL);
+       assert(!k->neg);
+
+       assert(ctx != NULL);
+       assert(prec != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       if (!E->is_in_mont) 
+               if (!EC_to_montgomery(E, mont, ctx)) return 0;
+
+
+       if (BN_is_zero(k))
+       {
+               if (!BN_zero(R->Z)) return 0;
+               R->is_in_mont = 1;
+               return 1;
+       }
+
+       j = BN_num_bits(k);
+       j--;
+
+       r = prec->r;
+
+       if (!BN_zero(R->Z)) return 0;
+       R->is_in_mont = 1;
+
+       while(j >= 0)
+       {
+               if (!BN_is_bit_set(k, j))
+               {
+                       if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
+                       j--;
+               }
+               else
+               {
+                       nextw = j - r;
+                       if (nextw < -1) nextw = -1;
+                       t = nextw + 1;                  
+                       while(!BN_is_bit_set(k, t))
+                       {
+                               t++;
+                       }
+
+                       if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
+
+                       j--;
+                       if (j < t) h = 0;
+                       else 
+                       {
+                               h = 1;
+                               for(; j > t; j--)
+                               {
+                                       h <<= 1;
+                                       if (BN_is_bit_set(k, j)) h++;
+                                       if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
+                               }
+                               if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
+                               j--;
+                       }
+
+                       if (!ECP_mont_add(R, R, prec->Pi[h], E, mont, ctx)) return 0;
+
+                       for (; j > nextw; j--)
+                       {
+                               if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
+                       }
+
+               }
+       }
+
+       return 1;
+}
+
+
+int ECP_mont_multiply2(EC_POINT *R, BIGNUM *k, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
+/* R = [k]P */
+{
+       int j, hj, kj;
+       BIGNUM *h;
+       EC_POINT *mP;
+
+       assert(R != NULL);
+       assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
+
+       assert(P != NULL);
+       assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
+
+       assert(E != NULL);
+       assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
+
+       assert(k != NULL);
+       assert(!k->neg);
+
+       assert(ctx != NULL);
+
+       assert(mont != NULL);
+       assert(mont->p != NULL);
+
+       if (!E->is_in_mont) 
+               if (!EC_to_montgomery(E, mont, ctx)) return 0;
+
+       if (!P->is_in_mont) 
+               if (!ECP_to_montgomery(P, mont, ctx)) return 0;
+
+
+       if (BN_is_zero(k))
+       {
+               if (!BN_zero(R->Z)) return 0;
+               R->is_in_mont = 1;
+               return 1;
+       }
+
+       if ((h = BN_dup(k)) == NULL) return 0;
+       
+       if (!BN_lshift1(h, h)) goto err;
+       if (!BN_add(h, h, k)) goto err;
+
+       if (!ECP_copy(R, P)) goto err;
+       if ((mP = ECP_mont_minus(P, mont)) == NULL) goto err;
+
+       for(j = BN_num_bits(h) - 2; j > 0; j--)
+       {
+               if (!ECP_mont_double(R, R, E, mont, ctx)) goto err;
+               kj = BN_is_bit_set(k, j);
+               hj = BN_is_bit_set(h, j);
+               if (hj == 1 && kj == 0)
+                       if (!ECP_mont_add(R, R, P, E, mont, ctx)) goto err;
+               if (hj == 0 && kj == 1)
+                       if (!ECP_mont_add(R, R, mP, E, mont, ctx)) goto err;
+       }
+
+       if (h != NULL) BN_free(h);
+       if (mP != NULL) ECP_clear_free(mP);
+       return 1;
+
+err:
+       if (h != NULL) BN_free(h);
+       if (mP != NULL) ECP_clear_free(mP);
+       return 0;
+}
+
+#endif /* MONTGOMERY */