Add assert()s to validate state in Auth Digest

Coverity checker picked up a number of cases where casting might (rarely)
cause a NULL pointer and a dereference occured afterwards.
This patch adds several assert statements to cause squid to abort at the
source of these errors rather than segfault later.
No code logic has been changed in any way.

diff --git a/src/auth/digest/auth_digest.cc b/src/auth/digest/auth_digest.cc
index 4b377cb04402329f3d15a0400a41f5078b5a13fc..eac41ce8fd5abeecdbd5b30a4ba1d91592c032ff 100644 (file)
--- a/src/auth/digest/auth_digest.cc
+++ b/src/auth/digest/auth_digest.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: auth_digest.cc,v 1.57 2007/05/29 13:31:46 amosjeffries Exp $
+ * $Id: auth_digest.cc,v 1.58 2007/08/03 02:16:59 amosjeffries Exp $
  *
  * DEBUG: section 29    Authenticator
  * AUTHOR: Robert Collins
@@ -588,6 +588,8 @@ AuthDigestUserRequest::authenticate(HttpRequest * request, ConnStateData::Pointe
 
     digest_user = dynamic_cast < digest_user_h * >(auth_user);
 
+    assert(digest_user != NULL);
+
     /* if the check has corrupted the user, just return */
 
     if (credentials() == Failed) {
@@ -786,7 +788,7 @@ AuthDigestConfig::fixHeader(AuthUserRequest *auth_user_request, HttpReply *rep,
     if (auth_user_request) {
         AuthDigestUserRequest *digest_request;
         digest_request = dynamic_cast < AuthDigestUserRequest * >(auth_user_request);
-        assert (digest_request);
+        assert (digest_request != NULL);
 
         stale = digest_request->flags.nonce_stale;
     }
@@ -842,7 +844,9 @@ authenticateDigestHandleReply(void *data, char *reply)
     auth_user_request = replyData->auth_user_request;
     digest_request = dynamic_cast < AuthDigestUserRequest * >(auth_user_request);
     assert(digest_request);
+
     digest_user = dynamic_cast < digest_user_h * >(auth_user_request->user());
+    assert(digest_user != NULL);
 
     if (reply && (strncasecmp(reply, "ERR", 3) == 0)) {
         digest_request->credentials(AuthDigestUserRequest::Failed);
@@ -1359,6 +1363,7 @@ AuthDigestUserRequest::module_start(RH * handler, void *data)
     digest_user_h *digest_user;
     assert(user()->auth_type == AUTH_DIGEST);
     digest_user = dynamic_cast < digest_user_h * >(user());
+    assert(digest_user != NULL);
     debugs(29, 9, "authenticateStart: '\"" << digest_user->username() << "\":\"" << realm << "\"'");
 
     if (digestConfig.authenticate == NULL) {