if (s->session->cipher != NULL)
s->session->cipher_id = s->session->cipher->id;
if (s->hit && (s->session->cipher_id != c->id)) {
- SSLerr(SSL_F_SET_CLIENT_CIPHERSUITE,
- SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
- return 0;
+ if (SSL_IS_TLS13(s)) {
+ /*
+ * In TLSv1.3 it is valid for the server to select a different
+ * ciphersuite as long as the hash is the same.
+ */
+ if (ssl_md(c->algorithm2)
+ != ssl_md(s->session->cipher->algorithm2)) {
+ SSLerr(SSL_F_SET_CLIENT_CIPHERSUITE,
+ SSL_R_CIPHERSUITE_DIGEST_HAS_CHANGED);
+ return 0;
+ }
+ } else {
+ /*
+ * Prior to TLSv1.3 resuming a session always meant using the same
+ * ciphersuite.
+ */
+ SSLerr(SSL_F_SET_CLIENT_CIPHERSUITE,
+ SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
+ return 0;
+ }
}
s->s3->tmp.new_cipher = c;