/* crypto/dsa/dsa_gen.c */
-/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
#undef GENUINE_DSA
#ifdef GENUINE_DSA
-#define HASH SHA
+/* Parameter generation follows the original release of FIPS PUB 186,
+ * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */
+#define HASH EVP_sha()
#else
-#define HASH SHA1
+/* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186,
+ * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in
+ * FIPS PUB 180-1) */
+#define HASH EVP_sha1()
#endif
+#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */
+
+#ifndef OPENSSL_NO_SHA
+
#include <stdio.h>
-#include <time.h>
#include "cryptlib.h"
-#include "sha.h"
-#include "bn.h"
-#include "dsa.h"
-#include "rand.h"
-
-DSA *DSA_generate_parameters(bits,seed_in,seed_len,counter_ret,h_ret,callback)
-int bits;
-unsigned char *seed_in;
-int seed_len;
-int *counter_ret;
-unsigned long *h_ret;
-void (*callback)();
+#include <openssl/evp.h>
+#include <openssl/bn.h>
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+#include "dsa_locl.h"
+
+int DSA_generate_parameters_ex(DSA *ret, int bits,
+ unsigned char *seed_in, int seed_len,
+ int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
+ {
+ if(ret->meth->dsa_paramgen)
+ return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
+ counter_ret, h_ret, cb);
+ else
+ {
+ const EVP_MD *evpmd;
+ size_t qbits = bits >= 2048 ? 256 : 160;
+
+ if (bits >= 2048)
+ {
+ qbits = 256;
+ evpmd = EVP_sha256();
+ }
+ else
+ {
+ qbits = 160;
+ evpmd = EVP_sha1();
+ }
+
+ return dsa_builtin_paramgen(ret, bits, qbits, evpmd,
+ seed_in, seed_len, counter_ret, h_ret, cb);
+ }
+ }
+
+int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
+ const EVP_MD *evpmd, unsigned char *seed_in, size_t seed_len,
+ int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
{
int ok=0;
- unsigned char seed[SHA_DIGEST_LENGTH];
- unsigned char md[SHA_DIGEST_LENGTH];
- unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH];
+ unsigned char seed[SHA256_DIGEST_LENGTH];
+ unsigned char md[SHA256_DIGEST_LENGTH];
+ unsigned char buf[SHA256_DIGEST_LENGTH],buf2[SHA256_DIGEST_LENGTH];
BIGNUM *r0,*W,*X,*c,*test;
BIGNUM *g=NULL,*q=NULL,*p=NULL;
- int k,n=0,i,b,m=0;
+ BN_MONT_CTX *mont=NULL;
+ int i, k,n=0,b,m=0, qsize = qbits >> 3;
int counter=0;
- BN_CTX *ctx=NULL,*ctx2=NULL;
+ int r=0;
+ BN_CTX *ctx=NULL;
unsigned int h=2;
- DSA *ret=NULL;
-
- if (bits < 512) bits=512;
- bits=(bits+63)/64*64;
-
- if ((seed_in != NULL) && (seed_len == 20))
- memcpy(seed,seed_in,seed_len);
-
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- ctx2=BN_CTX_new();
- if (ctx2 == NULL) goto err;
- ret=DSA_new();
- if (ret == NULL) goto err;
- r0=ctx2->bn[0];
- g=ctx2->bn[1];
- W=ctx2->bn[2];
- q=ctx2->bn[3];
- X=ctx2->bn[4];
- c=ctx2->bn[5];
- p=ctx2->bn[6];
- test=ctx2->bn[7];
-
- BN_lshift(test,BN_value_one(),bits-1);
+
+ if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH &&
+ qsize != SHA256_DIGEST_LENGTH)
+ /* invalid q size */
+ return 0;
+
+ if (evpmd == NULL)
+ /* use SHA1 as default */
+ evpmd = EVP_sha1();
+
+ if (bits < 512)
+ bits = 512;
+
+ bits = (bits+63)/64*64;
+
+ if (seed_len < (size_t)qsize)
+ seed_in = NULL; /* seed buffer too small -- ignore */
+ if (seed_len > (size_t)qsize)
+ seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger SEED,
+ * but our internal buffers are restricted to 160 bits*/
+ if (seed_in != NULL)
+ memcpy(seed, seed_in, seed_len);
+
+ if ((ctx=BN_CTX_new()) == NULL)
+ goto err;
+
+ if ((mont=BN_MONT_CTX_new()) == NULL)
+ goto err;
+
+ BN_CTX_start(ctx);
+ r0 = BN_CTX_get(ctx);
+ g = BN_CTX_get(ctx);
+ W = BN_CTX_get(ctx);
+ q = BN_CTX_get(ctx);
+ X = BN_CTX_get(ctx);
+ c = BN_CTX_get(ctx);
+ p = BN_CTX_get(ctx);
+ test = BN_CTX_get(ctx);
+
+ if (!BN_lshift(test,BN_value_one(),bits-1))
+ goto err;
for (;;)
{
- for (;;)
+ for (;;) /* find q */
{
+ int seed_is_random;
+
/* step 1 */
- if (callback != NULL) callback(0,m++);
+ if(!BN_GENCB_call(cb, 0, m++))
+ goto err;
if (!seed_len)
- RAND_bytes(seed,SHA_DIGEST_LENGTH);
+ {
+ RAND_pseudo_bytes(seed, qsize);
+ seed_is_random = 1;
+ }
else
- seed_len=0;
-
- memcpy(buf,seed,SHA_DIGEST_LENGTH);
- memcpy(buf2,seed,SHA_DIGEST_LENGTH);
- for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
+ {
+ seed_is_random = 0;
+ seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/
+ }
+ memcpy(buf , seed, qsize);
+ memcpy(buf2, seed, qsize);
+ /* precompute "SEED + 1" for step 7: */
+ for (i = qsize-1; i >= 0; i--)
{
buf[i]++;
- if (buf[i] != 0) break;
+ if (buf[i] != 0)
+ break;
}
/* step 2 */
- HASH(seed,SHA_DIGEST_LENGTH,md);
- HASH(buf,SHA_DIGEST_LENGTH,buf2);
- for (i=0; i<SHA_DIGEST_LENGTH; i++)
+ EVP_Digest(seed, qsize, md, NULL, evpmd, NULL);
+ EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL);
+ for (i = 0; i < qsize; i++)
md[i]^=buf2[i];
/* step 3 */
- md[0]|=0x80;
- md[SHA_DIGEST_LENGTH-1]|=0x01;
- if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) abort();
+ md[0] |= 0x80;
+ md[qsize-1] |= 0x01;
+ if (!BN_bin2bn(md, qsize, q))
+ goto err;
/* step 4 */
- if (DSA_is_prime(q,callback) > 0) break;
+ r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
+ seed_is_random, cb);
+ if (r > 0)
+ break;
+ if (r != 0)
+ goto err;
+
/* do a callback call */
/* step 5 */
}
- if (callback != NULL) callback(2,0);
- if (callback != NULL) callback(3,0);
+ if(!BN_GENCB_call(cb, 2, 0)) goto err;
+ if(!BN_GENCB_call(cb, 3, 0)) goto err;
/* step 6 */
counter=0;
+ /* "offset = 2" */
n=(bits-1)/160;
b=(bits-1)-n*160;
for (;;)
{
+ if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
+ goto err;
+
/* step 7 */
BN_zero(W);
+ /* now 'buf' contains "SEED + offset - 1" */
for (k=0; k<=n; k++)
{
- for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
+ /* obtain "SEED + offset + k" by incrementing: */
+ for (i = qsize-1; i >= 0; i--)
{
buf[i]++;
- if (buf[i] != 0) break;
+ if (buf[i] != 0)
+ break;
}
- HASH(buf,SHA_DIGEST_LENGTH,md);
+ EVP_Digest(buf, qsize, md ,NULL, evpmd, NULL);
/* step 8 */
- if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) abort();
- BN_lshift(r0,r0,160*k);
- BN_add(W,W,r0);
+ if (!BN_bin2bn(md, qsize, r0))
+ goto err;
+ if (!BN_lshift(r0,r0,(qsize << 3)*k)) goto err;
+ if (!BN_add(W,W,r0)) goto err;
}
/* more of step 8 */
- BN_mask_bits(W,bits-1);
- BN_copy(X,W); /* this should be ok */
- BN_add(X,X,test); /* this should be ok */
+ if (!BN_mask_bits(W,bits-1)) goto err;
+ if (!BN_copy(X,W)) goto err;
+ if (!BN_add(X,X,test)) goto err;
/* step 9 */
- BN_lshift1(r0,q);
- BN_mod(c,X,r0,ctx);
- BN_sub(r0,c,BN_value_one());
- BN_sub(p,X,r0);
+ if (!BN_lshift1(r0,q)) goto err;
+ if (!BN_mod(c,X,r0,ctx)) goto err;
+ if (!BN_sub(r0,c,BN_value_one())) goto err;
+ if (!BN_sub(p,X,r0)) goto err;
/* step 10 */
if (BN_cmp(p,test) >= 0)
{
/* step 11 */
- if (DSA_is_prime(p,callback) > 0)
- goto end;
+ r = BN_is_prime_fasttest_ex(p, DSS_prime_checks,
+ ctx, 1, cb);
+ if (r > 0)
+ goto end; /* found it */
+ if (r != 0)
+ goto err;
}
/* step 13 */
counter++;
+ /* "offset = offset + n + 1" */
/* step 14 */
if (counter >= 4096) break;
-
- if (callback != NULL) callback(0,counter);
}
}
end:
- if (callback != NULL) callback(2,1);
+ if(!BN_GENCB_call(cb, 2, 1))
+ goto err;
- /* We now need to gernerate g */
+ /* We now need to generate g */
/* Set r0=(p-1)/q */
- BN_sub(test,p,BN_value_one());
- BN_div(r0,NULL,test,q,ctx);
+ if (!BN_sub(test,p,BN_value_one())) goto err;
+ if (!BN_div(r0,NULL,test,q,ctx)) goto err;
+
+ if (!BN_set_word(test,h)) goto err;
+ if (!BN_MONT_CTX_set(mont,p,ctx)) goto err;
- BN_set_word(test,h);
for (;;)
{
/* g=test^r0%p */
- BN_mod_exp(g,test,r0,p,ctx);
+ if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err;
if (!BN_is_one(g)) break;
- BN_add(test,test,BN_value_one());
+ if (!BN_add(test,test,BN_value_one())) goto err;
h++;
}
- if (callback != NULL) callback(3,1);
+ if(!BN_GENCB_call(cb, 3, 1))
+ goto err;
ok=1;
err:
- if (!ok)
- {
- if (ret != NULL) DSA_free(ret);
- }
- else
+ if (ok)
{
+ if(ret->p) BN_free(ret->p);
+ if(ret->q) BN_free(ret->q);
+ if(ret->g) BN_free(ret->g);
ret->p=BN_dup(p);
ret->q=BN_dup(q);
ret->g=BN_dup(g);
- if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20);
+ if (ret->p == NULL || ret->q == NULL || ret->g == NULL)
+ {
+ ok=0;
+ goto err;
+ }
+ if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed, qsize);
if (counter_ret != NULL) *counter_ret=counter;
if (h_ret != NULL) *h_ret=h;
}
- BN_CTX_free(ctx);
- BN_CTX_free(ctx2);
- return(ok?ret:NULL);
- }
-
-int DSA_is_prime(w, callback)
-BIGNUM *w;
-void (*callback)();
- {
- int ok= -1,j,i,n;
- BN_CTX *ctx=NULL,*ctx2=NULL;
- BIGNUM *w_1,*b,*m,*z;
- int a;
-
- if (!BN_is_bit_set(w,0)) return(0);
-
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- ctx2=BN_CTX_new();
- if (ctx2 == NULL) goto err;
-
- m= ctx2->bn[2];
- b= ctx2->bn[3];
- z= ctx2->bn[4];
- w_1=ctx2->bn[5];
-
- /* step 1 */
- n=50;
-
- /* step 2 */
- if (!BN_sub(w_1,w,BN_value_one())) goto err;
- for (a=1; !BN_is_bit_set(w_1,a); a++)
- ;
- if (!BN_rshift(m,w_1,a)) goto err;
-
- for (i=1; i < n; i++)
+ if(ctx)
{
- /* step 3 */
- BN_rand(b,BN_num_bits(w)-2/*-1*/,0,0);
- BN_set_word(b,0x10001L);
-
- /* step 4 */
- j=0;
- if (!BN_mod_exp(z,b,m,w,ctx)) goto err;
-
- /* step 5 */
- for (;;)
- {
- if (((j == 0) && BN_is_one(z)) || (BN_cmp(z,w_1) == 0))
- break;
-
- /* step 6 */
- if ((j > 0) && BN_is_one(z))
- {
- ok=0;
- goto err;
- }
-
- j++;
- if (j >= a)
- {
- ok=0;
- goto err;
- }
-
- if (!BN_mod_mul(z,z,z,w,ctx)) goto err;
- if (callback != NULL) callback(1,j);
- }
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
}
-
- ok=1;
-err:
- if (ok == -1) DSAerr(DSA_F_DSA_IS_PRIME,ERR_R_BN_LIB);
- BN_CTX_free(ctx);
- BN_CTX_free(ctx2);
-
- return(ok);
+ if (mont != NULL) BN_MONT_CTX_free(mont);
+ return ok;
}
-
+#endif