- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
-
-
-size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
- unsigned char *buf, size_t len, BN_CTX *ctx)
- {
- size_t ret;
- BN_CTX *new_ctx = NULL;
- int used_ctx = 0;
- BIGNUM *x, *y;
- size_t field_len, i, skip;
-
- if ((form != POINT_CONVERSION_COMPRESSED)
- && (form != POINT_CONVERSION_UNCOMPRESSED)
- && (form != POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
- goto err;
- }
-
- if (EC_POINT_is_at_infinity(group, point))
- {
- /* encodes to a single 0 octet */
- if (buf != NULL)
- {
- if (len < 1)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- return 0;
- }
- buf[0] = 0;
- }
- return 1;
- }
-
-
- /* ret := required output buffer length */
- field_len = BN_num_bytes(&group->field);
- ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
- /* if 'buf' is NULL, just return required length */
- if (buf != NULL)
- {
- if (len < ret)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- goto err;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- used_ctx = 1;
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- if (y == NULL) goto err;
-
- if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-
- if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
- buf[0] = form + 1;
- else
- buf[0] = form;
-
- i = 1;
-
- skip = field_len - BN_num_bytes(x);
- if (skip > field_len)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- while (skip > 0)
- {
- buf[i++] = 0;
- skip--;
- }
- skip = BN_bn2bin(x, buf + i);
- i += skip;
- if (i != 1 + field_len)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
-
- if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
- {
- skip = field_len - BN_num_bytes(y);
- if (skip > field_len)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- while (skip > 0)
- {
- buf[i++] = 0;
- skip--;
- }
- skip = BN_bn2bin(y, buf + i);
- i += skip;
- }
-
- if (i != ret)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- }
-
- if (used_ctx)
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
-
- err:
- if (used_ctx)
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return 0;
- }
-
-
-int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
- const unsigned char *buf, size_t len, BN_CTX *ctx)
- {
- point_conversion_form_t form;
- int y_bit;
- BN_CTX *new_ctx = NULL;
- BIGNUM *x, *y;
- size_t field_len, enc_len;
- int ret = 0;
-
- if (len <= 0)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
- return 0;
- }
- form = buf[0];
- y_bit = form & 1;
- form = form & ~1;
- if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
- && (form != POINT_CONVERSION_UNCOMPRESSED)
- && (form != POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
- if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- if (form == 0)
- {
- if (len != 1)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- return EC_POINT_set_to_infinity(group, point);
- }
-
- field_len = BN_num_bytes(&group->field);
- enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
- if (len != enc_len)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- return 0;
- }
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- x = BN_CTX_get(ctx);
- y = BN_CTX_get(ctx);
- if (y == NULL) goto err;
-
- if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
- if (BN_ucmp(x, &group->field) >= 0)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
-
- if (form == POINT_CONVERSION_COMPRESSED)
- {
- if (!EC_POINT_set_compressed_coordinates_GFp(group, point, x, y_bit, ctx)) goto err;
- }
- else
- {
- if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
- if (BN_ucmp(y, &group->field) >= 0)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
- if (form == POINT_CONVERSION_HYBRID)
- {
- if (y_bit != BN_is_odd(y))
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
- goto err;
- }
- }
-
- if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
- }
-
- if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
- {
- ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
- goto err;
- }
-
- ret = 1;
-
- err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
-
-
-int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
- {
- int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
- int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
- const BIGNUM *p;
- BN_CTX *new_ctx = NULL;
- BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6;
- int ret = 0;
-
- if (a == b)
- return EC_POINT_dbl(group, r, a, ctx);
- if (EC_POINT_is_at_infinity(group, a))
- return EC_POINT_copy(r, b);
- if (EC_POINT_is_at_infinity(group, b))
- return EC_POINT_copy(r, a);
-
- field_mul = group->meth->field_mul;
- field_sqr = group->meth->field_sqr;
- p = &group->field;
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- BN_CTX_start(ctx);
- n0 = BN_CTX_get(ctx);
- n1 = BN_CTX_get(ctx);
- n2 = BN_CTX_get(ctx);
- n3 = BN_CTX_get(ctx);
- n4 = BN_CTX_get(ctx);
- n5 = BN_CTX_get(ctx);
- n6 = BN_CTX_get(ctx);
- if (n6 == NULL) goto end;
-
- /* Note that in this function we must not read components of 'a' or 'b'
- * once we have written the corresponding components of 'r'.
- * ('r' might be one of 'a' or 'b'.)
- */
-
- /* n1, n2 */
- if (b->Z_is_one)
- {
- if (!BN_copy(n1, &a->X)) goto end;
- if (!BN_copy(n2, &a->Y)) goto end;
- /* n1 = X_a */
- /* n2 = Y_a */
- }
- else
- {
- if (!field_sqr(group, n0, &b->Z, ctx)) goto end;
- if (!field_mul(group, n1, &a->X, n0, ctx)) goto end;
- /* n1 = X_a * Z_b^2 */
-
- if (!field_mul(group, n0, n0, &b->Z, ctx)) goto end;
- if (!field_mul(group, n2, &a->Y, n0, ctx)) goto end;
- /* n2 = Y_a * Z_b^3 */
- }
-
- /* n3, n4 */
- if (a->Z_is_one)
- {
- if (!BN_copy(n3, &b->X)) goto end;
- if (!BN_copy(n4, &b->Y)) goto end;
- /* n3 = X_b */
- /* n4 = Y_b */
- }
- else
- {
- if (!field_sqr(group, n0, &a->Z, ctx)) goto end;
- if (!field_mul(group, n3, &b->X, n0, ctx)) goto end;
- /* n3 = X_b * Z_a^2 */
-
- if (!field_mul(group, n0, n0, &a->Z, ctx)) goto end;
- if (!field_mul(group, n4, &b->Y, n0, ctx)) goto end;
- /* n4 = Y_b * Z_a^3 */
- }
-
- /* n5, n6 */
- if (!BN_mod_sub_quick(n5, n1, n3, p)) goto end;
- if (!BN_mod_sub_quick(n6, n2, n4, p)) goto end;
- /* n5 = n1 - n3 */
- /* n6 = n2 - n4 */
-
- if (BN_is_zero(n5))
- {
- if (BN_is_zero(n6))
- {
- /* a is the same point as b */
- BN_CTX_end(ctx);
- ret = EC_POINT_dbl(group, r, a, ctx);
- ctx = NULL;
- goto end;
- }
- else
- {
- /* a is the inverse of b */
- if (!BN_zero(&r->Z)) goto end;
- r->Z_is_one = 0;
- ret = 1;
- goto end;
- }
- }
-
- /* 'n7', 'n8' */
- if (!BN_mod_add_quick(n1, n1, n3, p)) goto end;
- if (!BN_mod_add_quick(n2, n2, n4, p)) goto end;
- /* 'n7' = n1 + n3 */
- /* 'n8' = n2 + n4 */
-
- /* Z_r */
- if (a->Z_is_one && b->Z_is_one)
- {
- if (!BN_copy(&r->Z, n5)) goto end;
- }
- else
- {
- if (a->Z_is_one)
- { if (!BN_copy(n0, &b->Z)) goto end; }
- else if (b->Z_is_one)
- { if (!BN_copy(n0, &a->Z)) goto end; }
- else
- { if (!field_mul(group, n0, &a->Z, &b->Z, ctx)) goto end; }
- if (!field_mul(group, &r->Z, n0, n5, ctx)) goto end;
- }
- r->Z_is_one = 0;
- /* Z_r = Z_a * Z_b * n5 */
-
- /* X_r */
- if (!field_sqr(group, n0, n6, ctx)) goto end;
- if (!field_sqr(group, n4, n5, ctx)) goto end;
- if (!field_mul(group, n3, n1, n4, ctx)) goto end;
- if (!BN_mod_sub_quick(&r->X, n0, n3, p)) goto end;
- /* X_r = n6^2 - n5^2 * 'n7' */
-
- /* 'n9' */
- if (!BN_mod_lshift1_quick(n0, &r->X, p)) goto end;
- if (!BN_mod_sub_quick(n0, n3, n0, p)) goto end;
- /* n9 = n5^2 * 'n7' - 2 * X_r */
-
- /* Y_r */
- if (!field_mul(group, n0, n0, n6, ctx)) goto end;
- if (!field_mul(group, n5, n4, n5, ctx)) goto end; /* now n5 is n5^3 */
- if (!field_mul(group, n1, n2, n5, ctx)) goto end;
- if (!BN_mod_sub_quick(n0, n0, n1, p)) goto end;
- if (BN_is_odd(n0))
- if (!BN_add(n0, n0, p)) goto end;
- /* now 0 <= n0 < 2*p, and n0 is even */
- if (!BN_rshift1(&r->Y, n0)) goto end;
- /* Y_r = (n6 * 'n9' - 'n8' * 'n5^3') / 2 */
-
- ret = 1;
+ BN_CTX_end(ctx);
+ BN_CTX_free(new_ctx);
+ return ret;
+}
+
+int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+ const EC_POINT *b, BN_CTX *ctx)
+{
+ int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
+ const BIGNUM *, BN_CTX *);
+ int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+ const BIGNUM *p;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6;
+ int ret = 0;
+
+ if (a == b)
+ return EC_POINT_dbl(group, r, a, ctx);
+ if (EC_POINT_is_at_infinity(group, a))
+ return EC_POINT_copy(r, b);
+ if (EC_POINT_is_at_infinity(group, b))
+ return EC_POINT_copy(r, a);
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+ p = group->field;
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ n0 = BN_CTX_get(ctx);
+ n1 = BN_CTX_get(ctx);
+ n2 = BN_CTX_get(ctx);
+ n3 = BN_CTX_get(ctx);
+ n4 = BN_CTX_get(ctx);
+ n5 = BN_CTX_get(ctx);
+ n6 = BN_CTX_get(ctx);
+ if (n6 == NULL)
+ goto end;
+
+ /*
+ * Note that in this function we must not read components of 'a' or 'b'
+ * once we have written the corresponding components of 'r'. ('r' might
+ * be one of 'a' or 'b'.)
+ */
+
+ /* n1, n2 */
+ if (b->Z_is_one) {
+ if (!BN_copy(n1, a->X))
+ goto end;
+ if (!BN_copy(n2, a->Y))
+ goto end;
+ /* n1 = X_a */
+ /* n2 = Y_a */
+ } else {
+ if (!field_sqr(group, n0, b->Z, ctx))
+ goto end;
+ if (!field_mul(group, n1, a->X, n0, ctx))
+ goto end;
+ /* n1 = X_a * Z_b^2 */
+
+ if (!field_mul(group, n0, n0, b->Z, ctx))
+ goto end;
+ if (!field_mul(group, n2, a->Y, n0, ctx))
+ goto end;
+ /* n2 = Y_a * Z_b^3 */
+ }
+
+ /* n3, n4 */
+ if (a->Z_is_one) {
+ if (!BN_copy(n3, b->X))
+ goto end;
+ if (!BN_copy(n4, b->Y))
+ goto end;
+ /* n3 = X_b */
+ /* n4 = Y_b */
+ } else {
+ if (!field_sqr(group, n0, a->Z, ctx))
+ goto end;
+ if (!field_mul(group, n3, b->X, n0, ctx))
+ goto end;
+ /* n3 = X_b * Z_a^2 */
+
+ if (!field_mul(group, n0, n0, a->Z, ctx))
+ goto end;
+ if (!field_mul(group, n4, b->Y, n0, ctx))
+ goto end;
+ /* n4 = Y_b * Z_a^3 */
+ }
+
+ /* n5, n6 */
+ if (!BN_mod_sub_quick(n5, n1, n3, p))
+ goto end;
+ if (!BN_mod_sub_quick(n6, n2, n4, p))
+ goto end;
+ /* n5 = n1 - n3 */
+ /* n6 = n2 - n4 */
+
+ if (BN_is_zero(n5)) {
+ if (BN_is_zero(n6)) {
+ /* a is the same point as b */
+ BN_CTX_end(ctx);
+ ret = EC_POINT_dbl(group, r, a, ctx);
+ ctx = NULL;
+ goto end;
+ } else {
+ /* a is the inverse of b */
+ BN_zero(r->Z);
+ r->Z_is_one = 0;
+ ret = 1;
+ goto end;
+ }
+ }
+
+ /* 'n7', 'n8' */
+ if (!BN_mod_add_quick(n1, n1, n3, p))
+ goto end;
+ if (!BN_mod_add_quick(n2, n2, n4, p))
+ goto end;
+ /* 'n7' = n1 + n3 */
+ /* 'n8' = n2 + n4 */
+
+ /* Z_r */
+ if (a->Z_is_one && b->Z_is_one) {
+ if (!BN_copy(r->Z, n5))
+ goto end;
+ } else {
+ if (a->Z_is_one) {
+ if (!BN_copy(n0, b->Z))
+ goto end;
+ } else if (b->Z_is_one) {
+ if (!BN_copy(n0, a->Z))
+ goto end;
+ } else {
+ if (!field_mul(group, n0, a->Z, b->Z, ctx))
+ goto end;
+ }
+ if (!field_mul(group, r->Z, n0, n5, ctx))
+ goto end;
+ }
+ r->Z_is_one = 0;
+ /* Z_r = Z_a * Z_b * n5 */
+
+ /* X_r */
+ if (!field_sqr(group, n0, n6, ctx))
+ goto end;
+ if (!field_sqr(group, n4, n5, ctx))
+ goto end;
+ if (!field_mul(group, n3, n1, n4, ctx))
+ goto end;
+ if (!BN_mod_sub_quick(r->X, n0, n3, p))
+ goto end;
+ /* X_r = n6^2 - n5^2 * 'n7' */
+
+ /* 'n9' */
+ if (!BN_mod_lshift1_quick(n0, r->X, p))
+ goto end;
+ if (!BN_mod_sub_quick(n0, n3, n0, p))
+ goto end;
+ /* n9 = n5^2 * 'n7' - 2 * X_r */
+
+ /* Y_r */
+ if (!field_mul(group, n0, n0, n6, ctx))
+ goto end;
+ if (!field_mul(group, n5, n4, n5, ctx))
+ goto end; /* now n5 is n5^3 */
+ if (!field_mul(group, n1, n2, n5, ctx))
+ goto end;
+ if (!BN_mod_sub_quick(n0, n0, n1, p))
+ goto end;
+ if (BN_is_odd(n0))
+ if (!BN_add(n0, n0, p))
+ goto end;
+ /* now 0 <= n0 < 2*p, and n0 is even */
+ if (!BN_rshift1(r->Y, n0))
+ goto end;
+ /* Y_r = (n6 * 'n9' - 'n8' * 'n5^3') / 2 */
+
+ ret = 1;