diff options
| author | Ismo Puustinen <ismo.puustinen@intel.com> | 2015-08-07 22:14:47 -0400 |
|---|---|---|
| committer | Rich Salz <rsalz@openssl.org> | 2015-08-28 11:22:34 -0400 |
| commit | 1d7df236dcb4f7c95707110753e5e77b19b9a0aa (patch) | |
| tree | 59c2b09e0a99518d70a358b4bfc21d102c02fda8 /crypto/dsa | |
| parent | a7cb67f4f2457724fbfbc39377f55c26f3aafa80 (diff) | |
GH367: Fix dsa keygen for too-short seed
If the seed value for dsa key generation is too short (< qsize),
return an error. Also update the documentation.
Signed-off-by: Rich Salz <rsalz@akamai.com>
Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit f00a10b89734e84fe80f98ad9e2e77b557c701ae)
Diffstat (limited to 'crypto/dsa')
| -rw-r--r-- | crypto/dsa/dsa_gen.c | 31 |
1 files changed, 13 insertions, 18 deletions
diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c index 5a328aaab5..847c874ad2 100644 --- a/crypto/dsa/dsa_gen.c +++ b/crypto/dsa/dsa_gen.c @@ -163,18 +163,15 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits, bits = (bits + 63) / 64 * 64; - /* - * NB: seed_len == 0 is special case: copy generated seed to seed_in if - * it is not NULL. - */ - if (seed_len && (seed_len < (size_t)qsize)) - seed_in = NULL; /* seed buffer too small -- ignore */ - if (seed_len > (size_t)qsize) - seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger - * SEED, but our internal buffers are - * restricted to 160 bits */ - if (seed_in != NULL) + if (seed_in != NULL) { + if (seed_len < (size_t)qsize) + return 0; + if (seed_len > (size_t)qsize) { + /* Don't overflow seed local variable. */ + seed_len = qsize; + } memcpy(seed, seed_in, seed_len); + } if ((ctx = BN_CTX_new()) == NULL) goto err; @@ -197,20 +194,18 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits, for (;;) { for (;;) { /* find q */ - int seed_is_random; + int seed_is_random = seed_in == NULL; /* step 1 */ if (!BN_GENCB_call(cb, 0, m++)) goto err; - if (!seed_len) { - if (RAND_pseudo_bytes(seed, qsize) < 0) + if (seed_is_random) { + if (RAND_bytes(seed, qsize) <= 0) goto err; - seed_is_random = 1; } else { - seed_is_random = 0; - seed_len = 0; /* use random seed if 'seed_in' turns out to - * be bad */ + /* If we come back through, use random seed next time. */ + seed_in = NULL; } memcpy(buf, seed, qsize); memcpy(buf2, seed, qsize); |