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.
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 937dcd4..302dd2b 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -642,7 +642,7 @@
}
#endif
-#ifndef MBEDTLS_TLS_DEFAULT_ALLOW_SHA1
+#ifndef MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
/* The test infrastructure requires a positive define */
#define MBEDTLS_X509__DEFAULT_FORBID_SHA1
#endif