SSL: logging levels of "unsupported protocol", "version too low".
Starting with OpenSSL 1.1.0, SSL_R_UNSUPPORTED_PROTOCOL instead of
SSL_R_UNKNOWN_PROTOCOL is reported when a protocol is disabled via
an SSL_OP_NO_* option.
Additionally, SSL_R_VERSION_TOO_LOW is reported when using MinProtocol
or when seclevel checks (as set by @SECLEVEL=n in the cipher string)
rejects a protocol, and this is what happens with SSLv3 and @SECLEVEL=1,
which is the default.
There is also the SSL_R_VERSION_TOO_HIGH error code, but it looks like
it is not possible to trigger it.
diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index b868056..c3bb90e 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -2079,6 +2079,7 @@
|| n == SSL_R_UNEXPECTED_RECORD /* 245 */
|| n == SSL_R_UNKNOWN_ALERT_TYPE /* 246 */
|| n == SSL_R_UNKNOWN_PROTOCOL /* 252 */
+ || n == SSL_R_UNSUPPORTED_PROTOCOL /* 258 */
|| n == SSL_R_WRONG_VERSION_NUMBER /* 267 */
|| n == SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC /* 281 */
#ifdef SSL_R_RENEGOTIATE_EXT_TOO_LONG
@@ -2095,6 +2096,9 @@
#ifdef SSL_R_INAPPROPRIATE_FALLBACK
|| n == SSL_R_INAPPROPRIATE_FALLBACK /* 373 */
#endif
+#ifdef SSL_R_VERSION_TOO_LOW
+ || n == SSL_R_VERSION_TOO_LOW /* 396 */
+#endif
|| n == 1000 /* SSL_R_SSLV3_ALERT_CLOSE_NOTIFY */
#ifdef SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE
|| n == SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE /* 1010 */
