Bump SSL client on [more] errors encountered before ssl_bump evaluation

... such as ERR_ACCESS_DENIED with HTTP/403 Forbidden triggered by an
http_access deny rule match.

The old code allowed ssl_bump step1 rules to be evaluated in the
presence of an error. An ssl_bump splicing decision would then trigger
the useless "send the error to the client now" processing logic instead
of going down the "to serve an error, bump the client first" path.

Furthermore, the ssl_bump evaluation result itself could be surprising
to the admin because ssl_bump (and most other) rules are not meant to be
evaluated for a transaction in an error state. This complicated triage.

Also polished an important comment to clarify that we want to bump on
error if (and only if) the SslBump feature is applicable to the failed
transaction (i.e., if the ssl_bump rules would have been evaluated if
there were no prior errors). The old comment could have been
misinterpreted that ssl_bump rules must be evaluated to allow an
"ssl_bump splice" match to hide the error.

This is a Measurement Factory project.

diff --git a/src/client_side_request.cc b/src/client_side_request.cc
index cf227440838aa0a09af0e3658544156453cbed29..59296de841f75603dbff33c0e7558bac46785acb 100644 (file)
--- a/src/client_side_request.cc
+++ b/src/client_side_request.cc
@@ -1442,6 +1442,13 @@ ClientRequestContext::sslBumpAccessCheck()
         return false;
     }
 
+    if (error) {
+        debugs(85, 5, "SslBump applies. Force bump action on error " << err_type_str[(error->type >= ERR_NONE && error->type < ERR_MAX) ? error->type : ERR_NONE]);
+        http->sslBumpNeed(Ssl::bumpBump);
+        http->al->ssl.bumpMode = Ssl::bumpBump;
+        return false;
+    }
+
     // Do not bump during authentication: clients would not proxy-authenticate
     // if we delay a 407 response and respond with 200 OK to CONNECT.
     if (error && error->httpStatus == Http::scProxyAuthenticationRequired) {
@@ -1781,8 +1788,9 @@ ClientHttpRequest::doCallouts()
     }
 
 #if USE_OPENSSL
-    // We need to check for SslBump even if the calloutContext->error is set
-    // because bumping may require delaying the error until after CONNECT.
+    // Even with calloutContext->error, we call sslBumpAccessCheck() to decide
+    // whether SslBump applies to this transaction. If it applies, we will
+    // attempt to bump the client to serve the error.
     if (!calloutContext->sslBumpCheckDone) {
         calloutContext->sslBumpCheckDone = true;
         if (calloutContext->sslBumpAccessCheck())