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author | Matt Caswell <matt@openssl.org> | 2014-07-10 23:47:31 +0100 |
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committer | Matt Caswell <matt@openssl.org> | 2014-07-13 22:36:03 +0100 |
commit | 02fef91630524703df3f3e567a09c7ddef8ec164 (patch) | |
tree | d02693ef42f45f5bc22b3877e469d96c7f40c256 | |
parent | 0b8cd5acd6616888a3cde85d6127c93894dfe797 (diff) | |
download | openssl-02fef91630524703df3f3e567a09c7ddef8ec164.tar.gz |
Fixed valgrind complaint due to BN_consttime_swap reading uninitialised data.
This is actually ok for this function, but initialised to zero anyway if
PURIFY defined.
This does have the impact of masking any *real* unitialised data reads in bn though.
Patch based on approach suggested by Rich Salz.
PR#3415
(cherry picked from commit 77747e2d9a5573b1dbc15e247ce18c03374c760c)
-rw-r--r-- | crypto/bn/bn_lib.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index 32a8fbaf51..c288844aa5 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -320,6 +320,15 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE); return(NULL); } +#ifdef PURIFY + /* Valgrind complains in BN_consttime_swap because we process the whole + * array even if it's not initialised yet. This doesn't matter in that + * function - what's important is constant time operation (we're not + * actually going to use the data) + */ + memset(a, 0, sizeof(BN_ULONG)*words); +#endif + #if 1 B=b->d; /* Check if the previous number needs to be copied */ |