For TLS 1.3 reject SHA1 TLS signatures
@@ -902,10 +902,11 @@ int tls12_check_peer_sigalg(SSL *s, uint16_t sig, EVP_PKEY *pkey)
}
lu = tls1_lookup_sigalg(sig);
/*
- * Check sigalgs is known and key type is consistent with signature:
- * RSA keys can be used for RSA-PSS
+ * Check sigalgs is known. Disallow SHA1 with TLS 1.3. Check key type is
+ * consistent with signature: RSA keys can be used for RSA-PSS
*/
- if (lu == NULL || (pkeyid != lu->sig
+ if (lu == NULL || (SSL_IS_TLS13(s) && lu->hash == NID_sha1)
+ || (pkeyid != lu->sig
&& (lu->sig != EVP_PKEY_RSA_PSS || pkeyid != EVP_PKEY_RSA))) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
@@ -2248,8 +2249,9 @@ int tls_choose_sigalg(SSL *s, int *al)
for (i = 0; i < s->cert->shared_sigalgslen; i++) {
lu = s->cert->shared_sigalgs[i];
- /* Skip DSA and RSA if not PSS */
- if (lu->sig == EVP_PKEY_DSA || lu->sig == EVP_PKEY_RSA)
+ /* Skip SHA1, DSA and RSA if not PSS */
+ if (lu->hash == NID_sha1 || lu->sig == EVP_PKEY_DSA
+ || lu->sig == EVP_PKEY_RSA)
continue;
if (ssl_md(lu->hash_idx) == NULL)
continue;
