Don't mix up pre- and post-handshake verification of DTLS clients.

Commit db965c9 addressed TLS clients only.

When verifying DTLS clients, don't consider config blocks with CA
settings ('tls') which differ from the one used for verifying the
certificate chain.

Original issue reported and analysed by Ralf Paffrath. DTLS being
vulnerable reported by Raphael Geisser.

Addresses issue RADSECPROXY-43, CVE-2012-4523.

ChangeLog

@@ -1,3 +1,9 @@
+2012-10-22 1.6.2-dev
+	Bug fixes (security):
+	- Fix the issue with verification of clients when using multiple
+	'tls' config blocks (RADSECPROXY-43) for DTLS too. Reported by
+	Raphael Geisser.
+
 2012-09-14 1.6.1
 	Bug fixes (security):
 	- When verifying clients, don't consider config blocks with CA

dtls.c

@@ -354,6 +354,7 @@ void *dtlsservernew(void *arg) {
     X509 *cert = NULL;
     SSL_CTX *ctx = NULL;
     uint8_t delay = 60;
+    struct tls *accepted_tls = NULL;
 
     debug(DBG_DBG, "dtlsservernew: starting");
     conf = find_clconf(handle, (struct sockaddr *)&params->addr, NULL);
@@ -367,10 +368,11 @@ void *dtlsservernew(void *arg) {
 	cert = verifytlscert(ssl);
         if (!cert)
             goto exit;
+        accepted_tls = conf->tlsconf;
     }
 
     while (conf) {
-	if (verifyconfcert(cert, conf)) {
+	if (accepted_tls == conf->tlsconf && verifyconfcert(cert, conf)) {
 	    X509_free(cert);
 	    client = addclient(conf, 1);
 	    if (client) {