Fix issue w/ deterministic ordering and string comparison of "http/1.1." and "h2"

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1670738 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/modules/ssl/ssl_engine_kernel.c b/modules/ssl/ssl_engine_kernel.c
index f6429801fa513dbd4d5b9c2fb612d56dd8d4d9a5..88dffb8346557ff3b6f06fdf35d4af6b7660455f 100644 (file)
--- a/modules/ssl/ssl_engine_kernel.c
+++ b/modules/ssl/ssl_engine_kernel.c
@@ -2177,7 +2177,7 @@ static int ssl_array_index(apr_array_header_t *array,
 }
 
 /*
- * Compare to ALPN protocol proposal. Result is similar to strcmp():
+ * Compare two ALPN protocol proposal. Result is similar to strcmp():
  * 0 gives same precedence, >0 means proto1 is prefered.
  */
 static int ssl_cmp_alpn_protos(modssl_ctx_t *ctx,
@@ -2254,14 +2254,8 @@ int ssl_callback_alpn_select(SSL *ssl,
         i += plen;
     }
     
-    /* Regardless of installed hooks, the http/1.1 protocol is always
-     * supported by us. Add it to the proposals if the client also
-     * offers it. */
     proposed_protos = apr_array_make(c->pool, client_protos->nelts+1,
                                      sizeof(char *));
-    if (ssl_array_index(client_protos, alpn_http1) >= 0) {
-        APR_ARRAY_PUSH(proposed_protos, const char*) = alpn_http1;
-    }
     
     if (sslconn->alpn_proposefns != NULL) {
         /* Invoke our alpn_propos_proto hooks, giving other modules a chance to
@@ -2280,9 +2274,16 @@ int ssl_callback_alpn_select(SSL *ssl,
     }
 
     if (proposed_protos->nelts <= 0) {
-        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(02839)
-                      "none of the client alpn protocols are supported");
-        return SSL_TLSEXT_ERR_ALERT_FATAL;
+        /* Regardless of installed hooks, the http/1.1 protocol is always
+         * supported by us. Choose it if none other matches. */
+        if (ssl_array_index(client_protos, alpn_http1) < 0) {
+            ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(02839)
+                          "none of the client alpn protocols are supported");
+            return SSL_TLSEXT_ERR_ALERT_FATAL;
+        }
+        *out = (const unsigned char*)alpn_http1;
+        *outlen = (unsigned char)strlen(alpn_http1);
+        return SSL_TLSEXT_ERR_OK;
     }
     
     /* Now select the most preferred protocol from the proposals. */