From 2cc3f68cde77af23c61fbad65470602ee86f2575 Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Wed, 7 Nov 2018 22:07:22 +0100 Subject: [PATCH] rsa/rsa_ossl.c: cache MONT_CTX for public modulus earlier. Blinding is performed more efficiently and securely if MONT_CTX for public modulus is available by the time blinding parameter are instantiated. So make sure it's the case. Reviewed-by: Matt Caswell Reviewed-by: Richard Levitte (Merged from https://github.com/openssl/openssl/pull/7586) --- crypto/rsa/rsa_ossl.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/crypto/rsa/rsa_ossl.c b/crypto/rsa/rsa_ossl.c index 2b1b006c28..09762b7d33 100644 --- a/crypto/rsa/rsa_ossl.c +++ b/crypto/rsa/rsa_ossl.c @@ -286,6 +286,11 @@ static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, goto err; } + if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) + if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, + rsa->n, ctx)) + goto err; + if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { blinding = rsa_get_blinding(rsa, &local_blinding, ctx); if (blinding == NULL) { @@ -318,13 +323,6 @@ static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, } BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); - if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) - if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock, - rsa->n, ctx)) { - BN_free(d); - goto err; - } - if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, rsa->_method_mod_n)) { BN_free(d); -- 2.25.1