diff options
Diffstat (limited to 'lib/libcrypto/dsa')
| -rw-r--r-- | lib/libcrypto/dsa/dsa_ameth.c | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/lib/libcrypto/dsa/dsa_ameth.c b/lib/libcrypto/dsa/dsa_ameth.c index b9ee49f0559..9bef6e5a13e 100644 --- a/lib/libcrypto/dsa/dsa_ameth.c +++ b/lib/libcrypto/dsa/dsa_ameth.c @@ -1,4 +1,4 @@ -/* $OpenBSD: dsa_ameth.c,v 1.17 2015/02/14 15:11:22 miod Exp $ */ +/* $OpenBSD: dsa_ameth.c,v 1.18 2015/09/10 18:12:55 miod Exp $ */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project 2006. */ @@ -519,13 +519,59 @@ static int old_dsa_priv_decode(EVP_PKEY *pkey, const unsigned char **pder, int derlen) { DSA *dsa; + BN_CTX *ctx = NULL; + BIGNUM *j, *p1, *newp1; - if (!(dsa = d2i_DSAPrivateKey (NULL, pder, derlen))) { + if (!(dsa = d2i_DSAPrivateKey(NULL, pder, derlen))) { DSAerr(DSA_F_OLD_DSA_PRIV_DECODE, ERR_R_DSA_LIB); return 0; } + + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + + /* + * Check that p and q are consistent with each other. + */ + + j = BN_CTX_get(ctx); + p1 = BN_CTX_get(ctx); + newp1 = BN_CTX_get(ctx); + if (j == NULL || p1 == NULL || newp1 == NULL) + goto err; + /* p1 = p - 1 */ + if (BN_sub(p1, dsa->p, BN_value_one()) == 0) + goto err; + /* j = (p - 1) / q */ + if (BN_div(j, NULL, p1, dsa->q, ctx) == 0) + goto err; + /* q * j should == p - 1 */ + if (BN_mul(newp1, dsa->q, j, ctx) == 0) + goto err; + if (BN_cmp(newp1, p1) != 0) { + DSAerr(DSA_F_DSA_PARAM_DECODE, DSA_R_BAD_Q_VALUE); + goto err; + } + + /* + * Check that q is not a composite number. + */ + + if (BN_is_prime_ex(dsa->q, BN_prime_checks, ctx, NULL) == 0) { + DSAerr(DSA_F_DSA_PARAM_DECODE, DSA_R_BAD_Q_VALUE); + goto err; + } + + BN_CTX_free(ctx); + EVP_PKEY_assign_DSA(pkey, dsa); return 1; + +err: + BN_CTX_free(ctx); + DSA_free(dsa); + return 0; } static int |