diff options
| author | Matt Caswell <matt@openssl.org> | 2015-08-10 12:00:29 +0100 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2015-08-11 19:57:01 +0100 |
| commit | 6a009812b2e249fed01488f6f19f9fbfd9ee74c4 (patch) | |
| tree | 56bd838e9d50be78716dd2437fbb2682b8fa98ee /crypto/bn/bn_mont.c | |
| parent | 61e72d761c945e128ca13599a98a187ac23650dd (diff) | |
Check for 0 modulus in BN_MONT_CTX_set
The function BN_MONT_CTX_set was assuming that the modulus was non-zero
and therefore that |mod->top| > 0. In an error situation that may not be
the case and could cause a seg fault.
This is a follow on from CVE-2015-1794.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Diffstat (limited to 'crypto/bn/bn_mont.c')
| -rw-r--r-- | crypto/bn/bn_mont.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c index 1580e978ce..d4d817a74f 100644 --- a/crypto/bn/bn_mont.c +++ b/crypto/bn/bn_mont.c @@ -351,6 +351,9 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) int ret = 0; BIGNUM *Ri, *R; + if (BN_is_zero(mod)) + return 0; + BN_CTX_start(ctx); if ((Ri = BN_CTX_get(ctx)) == NULL) goto err; |