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Implement internally opaque bn access from dsa

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Reviewed-by: Tim Hudson <tjh@openssl.org>
This commit is contained in:
Matt Caswell 2014-10-28 22:56:18 +00:00
parent 829ccf6ab6
commit c0d4390194
5 changed files with 82 additions and 56 deletions
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16
crypto/dsa/dsa_depr.c
View File

@ -89,16 +89,26 @@ DSA *DSA_generate_parameters(int bits,
void (*callback)(int, int, void *), void (*callback)(int, int, void *),
void *cb_arg) void *cb_arg)
{ {
BN_GENCB cb; BN_GENCB *cb;
DSA *ret; DSA *ret;
if ((ret=DSA_new()) == NULL) return NULL; if ((ret=DSA_new()) == NULL) return NULL;
cb = BN_GENCB_new();
if(!cb)
{
DSA_free(ret);
return NULL;
}
BN_GENCB_set_old(&cb, callback, cb_arg); BN_GENCB_set_old(cb, callback, cb_arg);
if(DSA_generate_parameters_ex(ret, bits, seed_in, seed_len, if(DSA_generate_parameters_ex(ret, bits, seed_in, seed_len,
counter_ret, h_ret, &cb)) counter_ret, h_ret, cb))
{
BN_GENCB_free(cb);
return ret; return ret;
}
BN_GENCB_free(cb);
DSA_free(ret); DSA_free(ret);
return NULL; return NULL;
} }

13
crypto/dsa/dsa_key.c
View File

@ -102,19 +102,24 @@ static int dsa_builtin_keygen(DSA *dsa)
pub_key=dsa->pub_key; pub_key=dsa->pub_key;
{ {
BIGNUM local_prk; BIGNUM *local_prk = NULL;
BIGNUM *prk; BIGNUM *prk;
if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0)
{ {
BN_init(&local_prk); local_prk = prk = BN_new();
prk = &local_prk; if(!local_prk) goto err;
BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME); BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
} }
else else
prk = priv_key; prk = priv_key;
if (!BN_mod_exp(pub_key,dsa->g,prk,dsa->p,ctx)) goto err; if (!BN_mod_exp(pub_key,dsa->g,prk,dsa->p,ctx))
{
if (local_prk != NULL) BN_free(local_prk);
goto err;
}
if (local_prk != NULL) BN_free(local_prk);
} }
dsa->priv_key=priv_key; dsa->priv_key=priv_key;

86
crypto/dsa/dsa_ossl.c
View File

@ -136,15 +136,16 @@ const DSA_METHOD *DSA_OpenSSL(void)
static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa) static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
{ {
BIGNUM *kinv=NULL,*r=NULL,*s=NULL; BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
BIGNUM m; BIGNUM *m;
BIGNUM xr; BIGNUM *xr;
BN_CTX *ctx=NULL; BN_CTX *ctx=NULL;
int reason=ERR_R_BN_LIB; int reason=ERR_R_BN_LIB;
DSA_SIG *ret=NULL; DSA_SIG *ret=NULL;
int noredo = 0; int noredo = 0;
BN_init(&m); m = BN_new();
BN_init(&xr); xr = BN_new();
if(!m || !xr) goto err;
if (!dsa->p || !dsa->q || !dsa->g) if (!dsa->p || !dsa->q || !dsa->g)
{ {
@ -177,12 +178,12 @@ redo:
* BN_num_bits(dsa->q) leftmost bits of the digest, see * BN_num_bits(dsa->q) leftmost bits of the digest, see
* fips 186-3, 4.2 */ * fips 186-3, 4.2 */
dlen = BN_num_bytes(dsa->q); dlen = BN_num_bytes(dsa->q);
if (BN_bin2bn(dgst,dlen,&m) == NULL) if (BN_bin2bn(dgst,dlen,m) == NULL)
goto err; goto err;
/* Compute s = inv(k) (m + xr) mod q */ /* 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_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_add(s, xr, m)) goto err; /* s = m + xr */
if (BN_cmp(s,dsa->q) > 0) if (BN_cmp(s,dsa->q) > 0)
if (!BN_sub(s,s,dsa->q)) goto err; if (!BN_sub(s,s,dsa->q)) goto err;
if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err; if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
@ -212,8 +213,8 @@ err:
BN_free(s); BN_free(s);
} }
if (ctx != NULL) BN_CTX_free(ctx); if (ctx != NULL) BN_CTX_free(ctx);
BN_clear_free(&m); BN_clear_free(m);
BN_clear_free(&xr); BN_clear_free(xr);
if (kinv != NULL) /* dsa->kinv is NULL now if we used it */ if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
BN_clear_free(kinv); BN_clear_free(kinv);
return(ret); return(ret);
@ -228,8 +229,8 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
BIGNUM **kinvp, BIGNUM **rp, BIGNUM **kinvp, BIGNUM **rp,
const unsigned char *dgst, int dlen) const unsigned char *dgst, int dlen)
{ {
BN_CTX *ctx; BN_CTX *ctx = NULL;
BIGNUM k,kq,*K,*kinv=NULL,*r=NULL; BIGNUM *k,*kq,*K,*kinv=NULL,*r=NULL;
int ret=0; int ret=0;
if (!dsa->p || !dsa->q || !dsa->g) if (!dsa->p || !dsa->q || !dsa->g)
@ -238,8 +239,9 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
return 0; return 0;
} }
BN_init(&k); k = BN_new();
BN_init(&kq); kq = BN_new();
if(!k || !kq) goto err;
if (ctx_in == NULL) if (ctx_in == NULL)
{ {
@ -259,18 +261,18 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
/* We calculate k from SHA512(private_key + H(message) /* We calculate k from SHA512(private_key + H(message)
* + random). This protects the private key from a weak * + random). This protects the private key from a weak
* PRNG. */ * PRNG. */
if (!BN_generate_dsa_nonce(&k, dsa->q, dsa->priv_key, dgst, if (!BN_generate_dsa_nonce(k, dsa->q, dsa->priv_key, dgst,
dlen, ctx)) dlen, ctx))
goto err; goto err;
} }
else else
#endif #endif
if (!BN_rand_range(&k, dsa->q)) goto err; if (!BN_rand_range(k, dsa->q)) goto err;
} while (BN_is_zero(&k)); } while (BN_is_zero(k));
if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0)
{ {
BN_set_flags(&k, BN_FLG_CONSTTIME); BN_set_flags(k, BN_FLG_CONSTTIME);
} }
if (dsa->flags & DSA_FLAG_CACHE_MONT_P) if (dsa->flags & DSA_FLAG_CACHE_MONT_P)
@ -285,7 +287,7 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0)
{ {
if (!BN_copy(&kq, &k)) goto err; if (!BN_copy(kq, k)) goto err;
/* We do not want timing information to leak the length of k, /* We do not want timing information to leak the length of k,
* so we compute g^k using an equivalent exponent of fixed length. * so we compute g^k using an equivalent exponent of fixed length.
@ -293,24 +295,24 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
* (This is a kludge that we need because the BN_mod_exp_mont() * (This is a kludge that we need because the BN_mod_exp_mont()
* does not let us specify the desired timing behaviour.) */ * does not let us specify the desired timing behaviour.) */
if (!BN_add(&kq, &kq, dsa->q)) goto err; if (!BN_add(kq, kq, dsa->q)) goto err;
if (BN_num_bits(&kq) <= BN_num_bits(dsa->q)) if (BN_num_bits(kq) <= BN_num_bits(dsa->q))
{ {
if (!BN_add(&kq, &kq, dsa->q)) goto err; if (!BN_add(kq, kq, dsa->q)) goto err;
} }
K = &kq; K = kq;
} }
else else
{ {
K = &k; K = k;
} }
DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, K, dsa->p, ctx, DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, K, dsa->p, ctx,
dsa->method_mont_p); dsa->method_mont_p);
if (!BN_mod(r,r,dsa->q,ctx)) goto err; if (!BN_mod(r,r,dsa->q,ctx)) goto err;
/* Compute part of 's = inv(k) (m + xr) mod q' */ /* Compute part of 's = inv(k) (m + xr) mod q' */
if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err; if ((kinv=BN_mod_inverse(NULL,k,dsa->q,ctx)) == NULL) goto err;
if (*kinvp != NULL) BN_clear_free(*kinvp); if (*kinvp != NULL) BN_clear_free(*kinvp);
*kinvp=kinv; *kinvp=kinv;
@ -326,8 +328,8 @@ err:
BN_clear_free(r); BN_clear_free(r);
} }
if (ctx_in == NULL) BN_CTX_free(ctx); if (ctx_in == NULL) BN_CTX_free(ctx);
BN_clear_free(&k); BN_clear_free(k);
BN_clear_free(&kq); BN_clear_free(kq);
return(ret); return(ret);
} }
@ -335,7 +337,7 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
DSA *dsa) DSA *dsa)
{ {
BN_CTX *ctx; BN_CTX *ctx;
BIGNUM u1,u2,t1; BIGNUM *u1,*u2,*t1;
BN_MONT_CTX *mont=NULL; BN_MONT_CTX *mont=NULL;
int ret = -1, i; int ret = -1, i;
if (!dsa->p || !dsa->q || !dsa->g) if (!dsa->p || !dsa->q || !dsa->g)
@ -357,11 +359,11 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MODULUS_TOO_LARGE); DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MODULUS_TOO_LARGE);
return -1; return -1;
} }
BN_init(&u1); u1 = BN_new();
BN_init(&u2); u2 = BN_new();
BN_init(&t1); t1 = BN_new();
ctx=BN_CTX_new();
if ((ctx=BN_CTX_new()) == NULL) goto err; if(!u1 || !u2 || !t1 || !ctx) goto err;
if (BN_is_zero(sig->r) || BN_is_negative(sig->r) || if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
BN_ucmp(sig->r, dsa->q) >= 0) BN_ucmp(sig->r, dsa->q) >= 0)
@ -378,7 +380,7 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
/* Calculate W = inv(S) mod Q /* Calculate W = inv(S) mod Q
* save W in u2 */ * save W in u2 */
if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err; if ((BN_mod_inverse(u2,sig->s,dsa->q,ctx)) == NULL) goto err;
/* save M in u1 */ /* save M in u1 */
if (dgst_len > (i >> 3)) if (dgst_len > (i >> 3))
@ -386,13 +388,13 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
* BN_num_bits(dsa->q) leftmost bits of the digest, see * BN_num_bits(dsa->q) leftmost bits of the digest, see
* fips 186-3, 4.2 */ * fips 186-3, 4.2 */
dgst_len = (i >> 3); dgst_len = (i >> 3);
if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err; if (BN_bin2bn(dgst,dgst_len,u1) == NULL) goto err;
/* u1 = M * w mod q */ /* u1 = M * w mod q */
if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err; if (!BN_mod_mul(u1,u1,u2,dsa->q,ctx)) goto err;
/* u2 = r * w mod q */ /* u2 = r * w mod q */
if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err; if (!BN_mod_mul(u2,sig->r,u2,dsa->q,ctx)) goto err;
if (dsa->flags & DSA_FLAG_CACHE_MONT_P) if (dsa->flags & DSA_FLAG_CACHE_MONT_P)
@ -404,21 +406,21 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
} }
DSA_MOD_EXP(goto err, dsa, &t1, dsa->g, &u1, dsa->pub_key, &u2, dsa->p, ctx, mont); DSA_MOD_EXP(goto err, dsa, t1, dsa->g, u1, dsa->pub_key, u2, dsa->p, ctx, mont);
/* BN_copy(&u1,&t1); */ /* BN_copy(&u1,&t1); */
/* let u1 = u1 mod q */ /* let u1 = u1 mod q */
if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err; if (!BN_mod(u1,t1,dsa->q,ctx)) goto err;
/* V is now in u1. If the signature is correct, it will be /* V is now in u1. If the signature is correct, it will be
* equal to R. */ * equal to R. */
ret=(BN_ucmp(&u1, sig->r) == 0); ret=(BN_ucmp(u1, sig->r) == 0);
err: err:
if (ret < 0) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB); if (ret < 0) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
if (ctx != NULL) BN_CTX_free(ctx); if (ctx != NULL) BN_CTX_free(ctx);
BN_free(&u1); if(u1) BN_free(u1);
BN_free(&u2); if(u2) BN_free(u2);
BN_free(&t1); if(t1) BN_free(t1);
return(ret); return(ret);
} }

9
crypto/dsa/dsa_pmeth.c
View File

@ -246,20 +246,25 @@ static int pkey_dsa_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
{ {
DSA *dsa = NULL; DSA *dsa = NULL;
DSA_PKEY_CTX *dctx = ctx->data; DSA_PKEY_CTX *dctx = ctx->data;
BN_GENCB *pcb, cb; BN_GENCB *pcb;
int ret; int ret;
if (ctx->pkey_gencb) if (ctx->pkey_gencb)
{ {
pcb = &cb; pcb = BN_GENCB_new();
if(!pcb) return 0;
evp_pkey_set_cb_translate(pcb, ctx); evp_pkey_set_cb_translate(pcb, ctx);
} }
else else
pcb = NULL; pcb = NULL;
dsa = DSA_new(); dsa = DSA_new();
if (!dsa) if (!dsa)
{
if(pcb) BN_GENCB_free(pcb);
return 0; return 0;
}
ret = dsa_builtin_paramgen(dsa, dctx->nbits, dctx->qbits, dctx->pmd, ret = dsa_builtin_paramgen(dsa, dctx->nbits, dctx->qbits, dctx->pmd,
NULL, 0, NULL, NULL, NULL, pcb); NULL, 0, NULL, NULL, NULL, pcb);
if(pcb) BN_GENCB_free(pcb);
if (ret) if (ret)
EVP_PKEY_assign_DSA(pkey, dsa); EVP_PKEY_assign_DSA(pkey, dsa);
else else

14
crypto/dsa/dsatest.c
View File

@ -136,7 +136,7 @@ static BIO *bio_err=NULL;
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
BN_GENCB cb; BN_GENCB *cb;
DSA *dsa=NULL; DSA *dsa=NULL;
int counter,ret=0,i,j; int counter,ret=0,i,j;
unsigned char buf[256]; unsigned char buf[256];
@ -156,9 +156,12 @@ int main(int argc, char **argv)
BIO_printf(bio_err,"test generation of DSA parameters\n"); BIO_printf(bio_err,"test generation of DSA parameters\n");
BN_GENCB_set(&cb, dsa_cb, bio_err); cb = BN_GENCB_new();
if(!cb) goto end;
BN_GENCB_set(cb, dsa_cb, bio_err);
if(((dsa = DSA_new()) == NULL) || !DSA_generate_parameters_ex(dsa, 512, if(((dsa = DSA_new()) == NULL) || !DSA_generate_parameters_ex(dsa, 512,
seed, 20, &counter, &h, &cb)) seed, 20, &counter, &h, cb))
goto end; goto end;
BIO_printf(bio_err,"seed\n"); BIO_printf(bio_err,"seed\n");
@ -221,6 +224,7 @@ end:
if (!ret) if (!ret)
ERR_print_errors(bio_err); ERR_print_errors(bio_err);
if (dsa != NULL) DSA_free(dsa); if (dsa != NULL) DSA_free(dsa);
if (cb != NULL) BN_GENCB_free(cb);
CRYPTO_cleanup_all_ex_data(); CRYPTO_cleanup_all_ex_data();
ERR_remove_thread_state(NULL); ERR_remove_thread_state(NULL);
ERR_free_strings(); ERR_free_strings();
@ -246,8 +250,8 @@ static int MS_CALLBACK dsa_cb(int p, int n, BN_GENCB *arg)
if (p == 1) c='+'; if (p == 1) c='+';
if (p == 2) { c='*'; ok++; } if (p == 2) { c='*'; ok++; }
if (p == 3) c='\n'; if (p == 3) c='\n';
BIO_write(arg->arg,&c,1); BIO_write(BN_GENCB_get_arg(arg),&c,1);
(void)BIO_flush(arg->arg); (void)BIO_flush(BN_GENCB_get_arg(arg));
if (!ok && (p == 0) && (num > 1)) if (!ok && (p == 0) && (num > 1))
{ {