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| author | Cesar Pereida Garcia <cesar.pereidagarcia@tut.fi> | 2019-08-19 10:33:14 +0300 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2019-08-27 09:25:51 +0100 |
| commit | 55611d549bcf65e0de04938adbf403ccf02f241b (patch) | |
| tree | c9e7997b7b205a7480efbf95a0f2d116eb5417d8 | |
| parent | 7fafaf27c2c2990fde2798424a38ce8443dae595 (diff) | |
Fix SCA vulnerability when using PVK and MSBLOB key formats
This commit addresses a side-channel vulnerability present when
PVK and MSBLOB key formats are loaded into OpenSSL.
The public key was not computed using a constant-time exponentiation
function.
This issue was discovered and reported by the NISEC group at TAU Finland.
Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9638)
| -rw-r--r-- | crypto/pem/pvkfmt.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/crypto/pem/pvkfmt.c b/crypto/pem/pvkfmt.c index f376f594b1..ff5674a99f 100644 --- a/crypto/pem/pvkfmt.c +++ b/crypto/pem/pvkfmt.c @@ -327,6 +327,8 @@ static EVP_PKEY *b2i_dss(const unsigned char **in, unsigned int length, } else { if (!read_lebn(&p, 20, &dsa->priv_key)) goto memerr; + /* Set constant time flag before public key calculation */ + BN_set_flags(dsa->priv_key, BN_FLG_CONSTTIME); /* Calculate public key */ if (!(dsa->pub_key = BN_new())) goto memerr; |