diff options
| author | Ben Laurie <ben@links.org> | 2013-01-28 17:31:49 +0000 |
|---|---|---|
| committer | Dr. Stephen Henson <steve@openssl.org> | 2013-02-06 13:56:12 +0000 |
| commit | fb0a59cc58e69203b1269d5f1c355f4944a8b350 (patch) | |
| tree | 63b6f5511fbe638585c834b9bf8416254bac2056 /crypto/evp | |
| parent | f5cd3561ba9363e6bcc58fcb6b1e94930f81967d (diff) | |
Make CBC decoding constant time.
This patch makes the decoding of SSLv3 and TLS CBC records constant
time. Without this, a timing side-channel can be used to build a padding
oracle and mount Vaudenay's attack.
This patch also disables the stitched AESNI+SHA mode pending a similar
fix to that code.
In order to be easy to backport, this change is implemented in ssl/,
rather than as a generic AEAD mode. In the future this should be changed
around so that HMAC isn't in ssl/, but crypto/ as FIPS expects.
(cherry picked from commit e130841bccfc0bb9da254dc84e23bc6a1c78a64e)
Diffstat (limited to 'crypto/evp')
| -rw-r--r-- | crypto/evp/c_allc.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/crypto/evp/c_allc.c b/crypto/evp/c_allc.c index 2a45d435e5..e230e6081e 100644 --- a/crypto/evp/c_allc.c +++ b/crypto/evp/c_allc.c @@ -195,11 +195,13 @@ void OpenSSL_add_all_ciphers(void) EVP_add_cipher(EVP_aes_256_xts()); EVP_add_cipher_alias(SN_aes_256_cbc,"AES256"); EVP_add_cipher_alias(SN_aes_256_cbc,"aes256"); +#if 0 /* Disabled because of timing side-channel leaks. */ #if !defined(OPENSSL_NO_SHA) && !defined(OPENSSL_NO_SHA1) EVP_add_cipher(EVP_aes_128_cbc_hmac_sha1()); EVP_add_cipher(EVP_aes_256_cbc_hmac_sha1()); #endif #endif +#endif #ifndef OPENSSL_NO_CAMELLIA EVP_add_cipher(EVP_camellia_128_ecb()); |