commit 5d2511c4d48eb197697466d1bd6b776cf09b0e7c
author Gilles Peskine <Gilles.Peskine@arm.com> Fri May 12 13:16:40 2017 +0200
committer Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com> Tue Jun 06 18:44:14 2017 +0200
tree 9b24707cff6e4a677d456523ae6b132d334ce374
parent 682df09159383c5456ea986220bdffe654d37583

SHA-1 deprecation: allow it in key exchange

By default, keep allowing SHA-1 in key exchange signatures. Disabling
it causes compatibility issues, especially with clients that use
TLS1.2 but don't send the signature_algorithms extension.

SHA-1 is forbidden in certificates by default, since it's vulnerable
to offline collision-based attacks.

library/ssl_tls.c

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d551047..ddedabb 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -7162,7 +7162,7 @@
     MBEDTLS_MD_SHA256,
     MBEDTLS_MD_SHA224,
 #endif
-#if defined(MBEDTLS_SHA1_C) && defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1)
+#if defined(MBEDTLS_SHA1_C) && defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE)
     MBEDTLS_MD_SHA1,
 #endif
     MBEDTLS_MD_NONE