diff options
Diffstat (limited to 'openssl/crypto/dsa')
| -rw-r--r-- | openssl/crypto/dsa/dsa_ossl.c | 796 |
1 files changed, 398 insertions, 398 deletions
diff --git a/openssl/crypto/dsa/dsa_ossl.c b/openssl/crypto/dsa/dsa_ossl.c index a3ddd7d28..927f6e2b8 100644 --- a/openssl/crypto/dsa/dsa_ossl.c +++ b/openssl/crypto/dsa/dsa_ossl.c @@ -1,398 +1,398 @@ -/* 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: - * 1. Redistributions of source code must retain the copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * "This product includes cryptographic software written by - * 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 - * 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 - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * 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 - * [including the GNU Public Licence.] - */ - -/* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */ - -#include <stdio.h> -#include "cryptlib.h" -#include <openssl/bn.h> -#include <openssl/sha.h> -#include <openssl/dsa.h> -#include <openssl/rand.h> -#include <openssl/asn1.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_init(DSA *dsa); -static int dsa_finish(DSA *dsa); - -static DSA_METHOD openssl_dsa_meth = { -"OpenSSL DSA method", -dsa_do_sign, -dsa_sign_setup, -dsa_do_verify, -NULL, /* dsa_mod_exp, */ -NULL, /* dsa_bn_mod_exp, */ -dsa_init, -dsa_finish, -0, -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; -} - -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 reason=ERR_R_BN_LIB; - DSA_SIG *ret=NULL; - - BN_init(&m); - BN_init(&xr); - - 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; - - 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 (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; - - 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,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; - } - - BN_init(&k); - BN_init(&kq); - - 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 (!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, - CRYPTO_LOCK_DSA, - 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; - - 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 (r != NULL) - BN_clear_free(r); - } - if (ctx_in == NULL) 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) - { - 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; - } - BN_init(&u1); - BN_init(&u2); - BN_init(&t1); - - if ((ctx=BN_CTX_new()) == 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, - CRYPTO_LOCK_DSA, 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: - /* XXX: surely this is wrong - if ret is 0, it just didn't verify; - there is no error in BN. Test should be ret == -1 (Ben) */ - 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); - } - -static int dsa_init(DSA *dsa) -{ - dsa->flags|=DSA_FLAG_CACHE_MONT_P; - return(1); -} - -static int dsa_finish(DSA *dsa) -{ - if(dsa->method_mont_p) - BN_MONT_CTX_free(dsa->method_mont_p); - return(1); -} - +/* 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:
+ * 1. Redistributions of source code must retain the copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * "This product includes cryptographic software written by
+ * 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
+ * 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
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * 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
+ * [including the GNU Public Licence.]
+ */
+
+/* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
+
+#include <stdio.h>
+#include "cryptlib.h"
+#include <openssl/bn.h>
+#include <openssl/sha.h>
+#include <openssl/dsa.h>
+#include <openssl/rand.h>
+#include <openssl/asn1.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_init(DSA *dsa);
+static int dsa_finish(DSA *dsa);
+
+static DSA_METHOD openssl_dsa_meth = {
+"OpenSSL DSA method",
+dsa_do_sign,
+dsa_sign_setup,
+dsa_do_verify,
+NULL, /* dsa_mod_exp, */
+NULL, /* dsa_bn_mod_exp, */
+dsa_init,
+dsa_finish,
+0,
+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;
+}
+
+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 reason=ERR_R_BN_LIB;
+ DSA_SIG *ret=NULL;
+
+ BN_init(&m);
+ BN_init(&xr);
+
+ 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;
+
+ 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 (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;
+
+ 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,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;
+ }
+
+ BN_init(&k);
+ BN_init(&kq);
+
+ 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 (!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,
+ CRYPTO_LOCK_DSA,
+ 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;
+
+ 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 (r != NULL)
+ BN_clear_free(r);
+ }
+ if (ctx_in == NULL) 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)
+ {
+ 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;
+ }
+ BN_init(&u1);
+ BN_init(&u2);
+ BN_init(&t1);
+
+ if ((ctx=BN_CTX_new()) == 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,
+ CRYPTO_LOCK_DSA, 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:
+ /* XXX: surely this is wrong - if ret is 0, it just didn't verify;
+ there is no error in BN. Test should be ret == -1 (Ben) */
+ 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);
+ }
+
+static int dsa_init(DSA *dsa)
+{
+ dsa->flags|=DSA_FLAG_CACHE_MONT_P;
+ return(1);
+}
+
+static int dsa_finish(DSA *dsa)
+{
+ if(dsa->method_mont_p)
+ BN_MONT_CTX_free(dsa->method_mont_p);
+ return(1);
+}
+
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