Mitigate the CRIME TLS flaw

If an attacker can cause a device to make an authenticated request to
a service via TLS while including a payload of the attacker's choice
in that request, and if TLS compression is enabled, the attacker can
uncover the plaintext authentication information by making a series of
guesses and observing changes in the length of the ciphertext.

This is CVE-2012-4929.

FS-6360 --resolve

Thanks-to: Brian West <brian@freeswitch.org>

diff --git a/libs/sofia-sip/libsofia-sip-ua/tport/tport_tls.c b/libs/sofia-sip/libsofia-sip-ua/tport/tport_tls.c
index c466ae4080c39698296ba34681928554e65f7680..74de1ed81703cbc70d4b73a97b279115fc8ea6b7 100644 (file)
--- a/libs/sofia-sip/libsofia-sip-ua/tport/tport_tls.c
+++ b/libs/sofia-sip/libsofia-sip-ua/tport/tport_tls.c
@@ -342,6 +342,10 @@ int tls_init_context(tls_t *tls, tls_issues_t const *ti)
 #endif
   SSL_CTX_sess_set_remove_cb(tls->ctx, NULL);
   SSL_CTX_set_timeout(tls->ctx, ti->timeout);
+#ifdef SSL_OP_NO_COMPRESSION
+  /* CRIME (CVE-2012-4929) mitigation */
+  SSL_CTX_set_options(tls->ctx, SSL_OP_NO_COMPRESSION);
+#endif
 
   /* Set callback if we have a passphrase */
   if (ti->passphrase != NULL) {