-/* crypto/dsa/dsa_ossl.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
- *
+ *
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
+ *
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
- *
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
+ * 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
+ *
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
- *
+ *
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
/* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
#include <stdio.h>
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
#include <openssl/bn.h>
+#include <openssl/sha.h>
#include <openssl/dsa.h>
#include <openssl/rand.h>
#include <openssl/asn1.h>
-#include <openssl/engine.h>
static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
-static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
-static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
- DSA *dsa);
+static int dsa_sign_setup_no_digest(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
+ BIGNUM **rp);
+static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
+ BIGNUM **rp, const unsigned char *dgst, int dlen);
+static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
+ DSA_SIG *sig, DSA *dsa);
static int dsa_init(DSA *dsa);
static int dsa_finish(DSA *dsa);
-static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
- BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
- BN_MONT_CTX *in_mont);
-static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx,
- BN_MONT_CTX *m_ctx);
static DSA_METHOD openssl_dsa_meth = {
-"OpenSSL DSA method",
-dsa_do_sign,
-dsa_sign_setup,
-dsa_do_verify,
-dsa_mod_exp,
-dsa_bn_mod_exp,
-dsa_init,
-dsa_finish,
-0,
-NULL
+ "OpenSSL DSA method",
+ dsa_do_sign,
+ dsa_sign_setup_no_digest,
+ dsa_do_verify,
+ NULL, /* dsa_mod_exp, */
+ NULL, /* dsa_bn_mod_exp, */
+ dsa_init,
+ dsa_finish,
+ DSA_FLAG_FIPS_METHOD,
+ NULL,
+ NULL,
+ NULL
};
+/*-
+ * These macro wrappers replace attempts to use the dsa_mod_exp() and
+ * bn_mod_exp() handlers in the DSA_METHOD structure. We avoid the problem of
+ * having a the macro work as an expression by bundling an "err_instr". So;
+ *
+ * if (!dsa->meth->bn_mod_exp(dsa, r,dsa->g,&k,dsa->p,ctx,
+ * dsa->method_mont_p)) goto err;
+ *
+ * can be replaced by;
+ *
+ * DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, &k, dsa->p, ctx,
+ * dsa->method_mont_p);
+ */
+
+#define DSA_MOD_EXP(err_instr,dsa,rr,a1,p1,a2,p2,m,ctx,in_mont) \
+ do { \
+ int _tmp_res53; \
+ if ((dsa)->meth->dsa_mod_exp) \
+ _tmp_res53 = (dsa)->meth->dsa_mod_exp((dsa), (rr), (a1), (p1), \
+ (a2), (p2), (m), (ctx), (in_mont)); \
+ else \
+ _tmp_res53 = BN_mod_exp2_mont((rr), (a1), (p1), (a2), (p2), \
+ (m), (ctx), (in_mont)); \
+ if (!_tmp_res53) err_instr; \
+ } while(0)
+#define DSA_BN_MOD_EXP(err_instr,dsa,r,a,p,m,ctx,m_ctx) \
+ do { \
+ int _tmp_res53; \
+ if ((dsa)->meth->bn_mod_exp) \
+ _tmp_res53 = (dsa)->meth->bn_mod_exp((dsa), (r), (a), (p), \
+ (m), (ctx), (m_ctx)); \
+ else \
+ _tmp_res53 = BN_mod_exp_mont((r), (a), (p), (m), (ctx), (m_ctx)); \
+ if (!_tmp_res53) err_instr; \
+ } while(0)
+
const DSA_METHOD *DSA_OpenSSL(void)
{
- return &openssl_dsa_meth;
+ return &openssl_dsa_meth;
}
static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
- {
- BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
- BIGNUM m;
- BIGNUM xr;
- BN_CTX *ctx=NULL;
- int i,reason=ERR_R_BN_LIB;
- DSA_SIG *ret=NULL;
-
- if (!dsa->p || !dsa->q || !dsa->g)
- {
- reason=DSA_R_MISSING_PARAMETERS;
- goto err;
- }
- BN_init(&m);
- BN_init(&xr);
- s=BN_new();
- if (s == NULL) goto err;
-
- i=BN_num_bytes(dsa->q); /* should be 20 */
- if ((dlen > i) || (dlen > 50))
- {
- reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
- goto err;
- }
-
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
-
- if ((dsa->kinv == NULL) || (dsa->r == NULL))
- {
- if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
- }
- else
- {
- kinv=dsa->kinv;
- dsa->kinv=NULL;
- r=dsa->r;
- dsa->r=NULL;
- }
-
- if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
-
- /* Compute s = inv(k) (m + xr) mod q */
- if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
- if (!BN_add(s, &xr, &m)) goto err; /* s = m + xr */
- if (BN_cmp(s,dsa->q) > 0)
- BN_sub(s,s,dsa->q);
- if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
-
- ret=DSA_SIG_new();
- if (ret == NULL) goto err;
- ret->r = r;
- ret->s = s;
-
-err:
- if (!ret)
- {
- DSAerr(DSA_F_DSA_DO_SIGN,reason);
- BN_free(r);
- BN_free(s);
- }
- if (ctx != NULL) BN_CTX_free(ctx);
- BN_clear_free(&m);
- BN_clear_free(&xr);
- if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
- BN_clear_free(kinv);
- return(ret);
- }
-
-static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
- {
- BN_CTX *ctx;
- BIGNUM k,*kinv=NULL,*r=NULL;
- int ret=0;
-
- if (!dsa->p || !dsa->q || !dsa->g)
- {
- DSAerr(DSA_F_DSA_SIGN_SETUP,DSA_R_MISSING_PARAMETERS);
- return 0;
- }
- if (ctx_in == NULL)
- {
- if ((ctx=BN_CTX_new()) == NULL) goto err;
- }
- else
- ctx=ctx_in;
-
- BN_init(&k);
- if ((r=BN_new()) == NULL) goto err;
- kinv=NULL;
-
- /* Get random k */
- do
- if (!BN_rand_range(&k, dsa->q)) goto err;
- while (BN_is_zero(&k));
-
- if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
- {
- if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
- if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
- dsa->p,ctx)) goto err;
- }
-
- /* Compute r = (g^k mod p) mod q */
- if (!dsa->meth->bn_mod_exp(dsa, r,dsa->g,&k,dsa->p,ctx,
- (BN_MONT_CTX *)dsa->method_mont_p)) goto err;
- if (!BN_mod(r,r,dsa->q,ctx)) goto err;
-
- /* Compute part of 's = inv(k) (m + xr) mod q' */
- if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
-
- if (*kinvp != NULL) BN_clear_free(*kinvp);
- *kinvp=kinv;
- kinv=NULL;
- if (*rp != NULL) BN_clear_free(*rp);
- *rp=r;
- ret=1;
-err:
- if (!ret)
- {
- DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
- if (kinv != NULL) BN_clear_free(kinv);
- if (r != NULL) BN_clear_free(r);
- }
- if (ctx_in == NULL) BN_CTX_free(ctx);
- if (kinv != NULL) BN_clear_free(kinv);
- BN_clear_free(&k);
- return(ret);
- }
-
-static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
- DSA *dsa)
- {
- BN_CTX *ctx;
- BIGNUM u1,u2,t1;
- BN_MONT_CTX *mont=NULL;
- int ret = -1;
- if (!dsa->p || !dsa->q || !dsa->g)
- {
- DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MISSING_PARAMETERS);
- return -1;
- }
-
- if ((ctx=BN_CTX_new()) == NULL) goto err;
- BN_init(&u1);
- BN_init(&u2);
- BN_init(&t1);
-
- if (BN_is_zero(sig->r) || BN_get_sign(sig->r) ||
- BN_ucmp(sig->r, dsa->q) >= 0)
- {
- ret = 0;
- goto err;
- }
- if (BN_is_zero(sig->s) || BN_get_sign(sig->s) ||
- BN_ucmp(sig->s, dsa->q) >= 0)
- {
- ret = 0;
- goto err;
- }
-
- /* Calculate W = inv(S) mod Q
- * save W in u2 */
- if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
-
- /* save M in u1 */
- if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
-
- /* u1 = M * w mod q */
- if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err;
-
- /* u2 = r * w mod q */
- if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err;
-
- if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
- {
- if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
- if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
- dsa->p,ctx)) goto err;
- }
- mont=(BN_MONT_CTX *)dsa->method_mont_p;
-
-#if 0
- {
- BIGNUM t2;
-
- BN_init(&t2);
- /* v = ( g^u1 * y^u2 mod p ) mod q */
- /* let t1 = g ^ u1 mod p */
- if (!BN_mod_exp_mont(&t1,dsa->g,&u1,dsa->p,ctx,mont)) goto err;
- /* let t2 = y ^ u2 mod p */
- if (!BN_mod_exp_mont(&t2,dsa->pub_key,&u2,dsa->p,ctx,mont)) goto err;
- /* let u1 = t1 * t2 mod p */
- if (!BN_mod_mul(&u1,&t1,&t2,dsa->p,ctx)) goto err_bn;
- BN_free(&t2);
- }
- /* let u1 = u1 mod q */
- if (!BN_mod(&u1,&u1,dsa->q,ctx)) goto err;
-#else
- {
- if (!dsa->meth->dsa_mod_exp(dsa, &t1,dsa->g,&u1,dsa->pub_key,&u2,
- dsa->p,ctx,mont)) goto err;
- /* BN_copy(&u1,&t1); */
- /* let u1 = u1 mod q */
- if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err;
- }
-#endif
- /* V is now in u1. If the signature is correct, it will be
- * equal to R. */
- ret=(BN_ucmp(&u1, sig->r) == 0);
-
- err:
- if (ret != 1) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
- if (ctx != NULL) BN_CTX_free(ctx);
- BN_free(&u1);
- BN_free(&u2);
- BN_free(&t1);
- return(ret);
- }
+{
+ BIGNUM *kinv = NULL, *r = NULL, *s = NULL;
+ BIGNUM *m;
+ BIGNUM *xr;
+ BN_CTX *ctx = NULL;
+ int reason = ERR_R_BN_LIB;
+ DSA_SIG *ret = NULL;
+ int noredo = 0;
+
+ m = BN_new();
+ xr = BN_new();
+ if (m == NULL || xr == NULL)
+ goto err;
+
+ if (!dsa->p || !dsa->q || !dsa->g) {
+ reason = DSA_R_MISSING_PARAMETERS;
+ goto err;
+ }
+
+ s = BN_new();
+ if (s == NULL)
+ goto err;
+ ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+ redo:
+ if (!dsa_sign_setup(dsa, ctx, &kinv, &r, dgst, dlen))
+ goto err;
+
+ if (dlen > BN_num_bytes(dsa->q))
+ /*
+ * if the digest length is greater than the size of q use the
+ * BN_num_bits(dsa->q) leftmost bits of the digest, see fips 186-3,
+ * 4.2
+ */
+ dlen = BN_num_bytes(dsa->q);
+ if (BN_bin2bn(dgst, dlen, m) == NULL)
+ goto err;
+
+ /* Compute s = inv(k) (m + xr) mod q */
+ if (!BN_mod_mul(xr, dsa->priv_key, r, dsa->q, ctx))
+ goto err; /* s = xr */
+ if (!BN_add(s, xr, m))
+ goto err; /* s = m + xr */
+ if (BN_cmp(s, dsa->q) > 0)
+ if (!BN_sub(s, s, dsa->q))
+ goto err;
+ if (!BN_mod_mul(s, s, kinv, dsa->q, ctx))
+ goto err;
+
+ /*
+ * Redo if r or s is zero as required by FIPS 186-3: this is very
+ * unlikely.
+ */
+ if (BN_is_zero(r) || BN_is_zero(s)) {
+ if (noredo) {
+ reason = DSA_R_NEED_NEW_SETUP_VALUES;
+ goto err;
+ }
+ goto redo;
+ }
+ ret = DSA_SIG_new();
+ if (ret == NULL)
+ goto err;
+ ret->r = r;
+ ret->s = s;
+
+ err:
+ if (ret == NULL) {
+ DSAerr(DSA_F_DSA_DO_SIGN, reason);
+ BN_free(r);
+ BN_free(s);
+ }
+ BN_CTX_free(ctx);
+ BN_clear_free(m);
+ BN_clear_free(xr);
+ BN_clear_free(kinv);
+ return (ret);
+}
-static int dsa_init(DSA *dsa)
+static int dsa_sign_setup_no_digest(DSA *dsa, BN_CTX *ctx_in,
+ BIGNUM **kinvp, BIGNUM **rp)
{
- dsa->flags|=DSA_FLAG_CACHE_MONT_P;
- return(1);
+ return dsa_sign_setup(dsa, ctx_in, kinvp, rp, NULL, 0);
}
-static int dsa_finish(DSA *dsa)
+static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
+ BIGNUM **kinvp, BIGNUM **rp,
+ const unsigned char *dgst, int dlen)
+{
+ BN_CTX *ctx = NULL;
+ BIGNUM *k, *kq, *K, *kinv = NULL, *r = NULL;
+ int ret = 0;
+
+ if (!dsa->p || !dsa->q || !dsa->g) {
+ DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_MISSING_PARAMETERS);
+ return 0;
+ }
+
+ k = BN_new();
+ kq = BN_new();
+ if (k == NULL || kq == NULL)
+ goto err;
+
+ if (ctx_in == NULL) {
+ if ((ctx = BN_CTX_new()) == NULL)
+ goto err;
+ } else
+ ctx = ctx_in;
+
+ if ((r = BN_new()) == NULL)
+ goto err;
+
+ /* Get random k */
+ do {
+ if (dgst != NULL) {
+ /*
+ * We calculate k from SHA512(private_key + H(message) + random).
+ * This protects the private key from a weak PRNG.
+ */
+ if (!BN_generate_dsa_nonce(k, dsa->q, dsa->priv_key, dgst,
+ dlen, ctx))
+ goto err;
+ } else if (!BN_rand_range(k, dsa->q))
+ goto err;
+ } while (BN_is_zero(k));
+
+ if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
+ BN_set_flags(k, BN_FLG_CONSTTIME);
+ }
+
+ if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
+ if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,
+ dsa->lock, dsa->p, ctx))
+ goto err;
+ }
+
+ /* Compute r = (g^k mod p) mod q */
+
+ if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
+ if (!BN_copy(kq, k))
+ goto err;
+
+ /*
+ * We do not want timing information to leak the length of k, so we
+ * compute g^k using an equivalent exponent of fixed length. (This
+ * is a kludge that we need because the BN_mod_exp_mont() does not
+ * let us specify the desired timing behaviour.)
+ */
+
+ if (!BN_add(kq, kq, dsa->q))
+ goto err;
+ if (BN_num_bits(kq) <= BN_num_bits(dsa->q)) {
+ if (!BN_add(kq, kq, dsa->q))
+ goto err;
+ }
+
+ K = kq;
+ } else {
+ K = k;
+ }
+ DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, K, dsa->p, ctx,
+ dsa->method_mont_p);
+ if (!BN_mod(r, r, dsa->q, ctx))
+ goto err;
+
+ /* Compute part of 's = inv(k) (m + xr) mod q' */
+ if ((kinv = BN_mod_inverse(NULL, k, dsa->q, ctx)) == NULL)
+ goto err;
+
+ BN_clear_free(*kinvp);
+ *kinvp = kinv;
+ kinv = NULL;
+ BN_clear_free(*rp);
+ *rp = r;
+ ret = 1;
+ err:
+ if (!ret) {
+ DSAerr(DSA_F_DSA_SIGN_SETUP, ERR_R_BN_LIB);
+ BN_clear_free(r);
+ }
+ if (ctx != ctx_in)
+ BN_CTX_free(ctx);
+ BN_clear_free(k);
+ BN_clear_free(kq);
+ return (ret);
+}
+
+static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
+ DSA_SIG *sig, DSA *dsa)
{
- if(dsa->method_mont_p)
- BN_MONT_CTX_free((BN_MONT_CTX *)dsa->method_mont_p);
- return(1);
+ BN_CTX *ctx;
+ BIGNUM *u1, *u2, *t1;
+ BN_MONT_CTX *mont = NULL;
+ int ret = -1, i;
+ if (!dsa->p || !dsa->q || !dsa->g) {
+ DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_MISSING_PARAMETERS);
+ return -1;
+ }
+
+ i = BN_num_bits(dsa->q);
+ /* fips 186-3 allows only different sizes for q */
+ if (i != 160 && i != 224 && i != 256) {
+ DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_BAD_Q_VALUE);
+ return -1;
+ }
+
+ if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) {
+ DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_MODULUS_TOO_LARGE);
+ return -1;
+ }
+ u1 = BN_new();
+ u2 = BN_new();
+ t1 = BN_new();
+ ctx = BN_CTX_new();
+ if (u1 == NULL || u2 == NULL || t1 == NULL || ctx == NULL)
+ goto err;
+
+ if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
+ BN_ucmp(sig->r, dsa->q) >= 0) {
+ ret = 0;
+ goto err;
+ }
+ if (BN_is_zero(sig->s) || BN_is_negative(sig->s) ||
+ BN_ucmp(sig->s, dsa->q) >= 0) {
+ ret = 0;
+ goto err;
+ }
+
+ /*
+ * Calculate W = inv(S) mod Q save W in u2
+ */
+ if ((BN_mod_inverse(u2, sig->s, dsa->q, ctx)) == NULL)
+ goto err;
+
+ /* save M in u1 */
+ if (dgst_len > (i >> 3))
+ /*
+ * if the digest length is greater than the size of q use the
+ * BN_num_bits(dsa->q) leftmost bits of the digest, see fips 186-3,
+ * 4.2
+ */
+ dgst_len = (i >> 3);
+ if (BN_bin2bn(dgst, dgst_len, u1) == NULL)
+ goto err;
+
+ /* u1 = M * w mod q */
+ if (!BN_mod_mul(u1, u1, u2, dsa->q, ctx))
+ goto err;
+
+ /* u2 = r * w mod q */
+ if (!BN_mod_mul(u2, sig->r, u2, dsa->q, ctx))
+ goto err;
+
+ if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
+ mont = BN_MONT_CTX_set_locked(&dsa->method_mont_p,
+ dsa->lock, dsa->p, ctx);
+ if (!mont)
+ goto err;
+ }
+
+ DSA_MOD_EXP(goto err, dsa, t1, dsa->g, u1, dsa->pub_key, u2, dsa->p, ctx,
+ mont);
+ /* BN_copy(&u1,&t1); */
+ /* let u1 = u1 mod q */
+ if (!BN_mod(u1, t1, dsa->q, ctx))
+ goto err;
+
+ /*
+ * V is now in u1. If the signature is correct, it will be equal to R.
+ */
+ ret = (BN_ucmp(u1, sig->r) == 0);
+
+ err:
+ if (ret < 0)
+ DSAerr(DSA_F_DSA_DO_VERIFY, ERR_R_BN_LIB);
+ BN_CTX_free(ctx);
+ BN_free(u1);
+ BN_free(u2);
+ BN_free(t1);
+ return (ret);
}
-static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
- BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
- BN_MONT_CTX *in_mont)
+static int dsa_init(DSA *dsa)
{
- return BN_mod_exp2_mont(rr, a1, p1, a2, p2, m, ctx, in_mont);
+ dsa->flags |= DSA_FLAG_CACHE_MONT_P;
+ return (1);
}
-
-static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx,
- BN_MONT_CTX *m_ctx)
+
+static int dsa_finish(DSA *dsa)
{
- return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+ BN_MONT_CTX_free(dsa->method_mont_p);
+ return (1);
}
projects / openssl.git / blobdiff