From 1496376fee5af11aeeff579937776a2bfc6ba1c4 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Thu, 8 Jun 2017 21:33:10 +0000 Subject: [PATCH] Fix the software fallback for GCM to validate the existing tag for decrypts. Sponsored by: Chelsio Communications --- sys/dev/cxgbe/crypto/t4_crypto.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/sys/dev/cxgbe/crypto/t4_crypto.c b/sys/dev/cxgbe/crypto/t4_crypto.c index d549ce4032c7..eb341f9720e2 100644 --- a/sys/dev/cxgbe/crypto/t4_crypto.c +++ b/sys/dev/cxgbe/crypto/t4_crypto.c @@ -1398,9 +1398,20 @@ ccr_gcm_soft(struct ccr_session *s, struct cryptop *crp, AES_GMAC_Update(&gmac_ctx, block, sizeof(block)); AES_GMAC_Final(digest, &gmac_ctx); - crypto_copyback(crp->crp_flags, crp->crp_buf, crda->crd_inject, - sizeof(digest), digest); - crp->crp_etype = 0; + if (crde->crd_flags & CRD_F_ENCRYPT) { + crypto_copyback(crp->crp_flags, crp->crp_buf, crda->crd_inject, + sizeof(digest), digest); + crp->crp_etype = 0; + } else { + char digest2[GMAC_DIGEST_LEN]; + + crypto_copydata(crp->crp_flags, crp->crp_buf, crda->crd_inject, + sizeof(digest2), digest2); + if (timingsafe_bcmp(digest, digest2, sizeof(digest)) == 0) + crp->crp_etype = 0; + else + crp->crp_etype = EBADMSG; + } crypto_done(crp); }