1999-08-23 01:57:38 +08:00
|
|
|
/* 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/dsa.h>
|
|
|
|
#include <openssl/rand.h>
|
|
|
|
#include <openssl/asn1.h>
|
2000-10-27 05:07:28 +08:00
|
|
|
#include <openssl/engine.h>
|
1999-08-23 01:57:38 +08:00
|
|
|
|
|
|
|
static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
|
1999-11-04 08:45:35 +08:00
|
|
|
static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
|
1999-08-23 01:57:38 +08:00
|
|
|
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
|
|
|
|
};
|
|
|
|
|
2000-11-07 21:54:39 +08:00
|
|
|
const DSA_METHOD *DSA_OpenSSL(void)
|
1999-08-23 01:57:38 +08:00
|
|
|
{
|
|
|
|
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;
|
|
|
|
|
|
|
|
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);
|
|
|
|
}
|
|
|
|
|
1999-11-04 08:45:35 +08:00
|
|
|
static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
|
1999-08-23 01:57:38 +08:00
|
|
|
{
|
|
|
|
BN_CTX *ctx;
|
|
|
|
BIGNUM k,*kinv=NULL,*r=NULL;
|
|
|
|
int ret=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 */
|
2001-02-08 20:14:51 +08:00
|
|
|
do
|
2001-02-10 08:34:02 +08:00
|
|
|
if (!BN_rand_range(&k, dsa->q)) goto err;
|
2001-02-08 20:14:51 +08:00
|
|
|
while (BN_is_zero(&k));
|
1999-08-23 01:57:38 +08:00
|
|
|
|
|
|
|
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 */
|
2000-10-27 05:07:28 +08:00
|
|
|
if (!ENGINE_get_DSA(dsa->engine)->bn_mod_exp(dsa, r,dsa->g,&k,dsa->p,ctx,
|
1999-08-23 01:57:38 +08:00
|
|
|
(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 ((ctx=BN_CTX_new()) == NULL) goto err;
|
|
|
|
BN_init(&u1);
|
|
|
|
BN_init(&u2);
|
|
|
|
BN_init(&t1);
|
|
|
|
|
|
|
|
/* 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
|
|
|
|
{
|
2000-10-27 05:07:28 +08:00
|
|
|
if (!ENGINE_get_DSA(dsa->engine)->dsa_mod_exp(dsa, &t1,dsa->g,&u1,dsa->pub_key,&u2,
|
1999-08-23 01:57:38 +08:00
|
|
|
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);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int dsa_init(DSA *dsa)
|
|
|
|
{
|
1999-08-24 07:11:32 +08:00
|
|
|
dsa->flags|=DSA_FLAG_CACHE_MONT_P;
|
1999-08-23 01:57:38 +08:00
|
|
|
return(1);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int dsa_finish(DSA *dsa)
|
|
|
|
{
|
1999-08-24 07:11:32 +08:00
|
|
|
if(dsa->method_mont_p)
|
|
|
|
BN_MONT_CTX_free((BN_MONT_CTX *)dsa->method_mont_p);
|
1999-08-23 01:57:38 +08:00
|
|
|
return(1);
|
|
|
|
}
|
|
|
|
|
|
|
|
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)
|
|
|
|
{
|
|
|
|
return BN_mod_exp2_mont(rr, a1, p1, a2, p2, m, 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)
|
|
|
|
{
|
|
|
|
return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
|
|
|
|
}
|