Merge branch 'gnutls_priority_override_option'

Signed-off-by: Daniel Lenski <dlenski@gmail.com>

cstp.c

@@ -637,8 +637,6 @@ static int start_cstp_connection(struct openconnect_info *vpninfo)
 	free_optlist(old_cstp_opts);
 	vpn_progress(vpninfo, PRG_INFO, _("CSTP connected. DPD %d, Keepalive %d\n"),
 		     vpninfo->ssl_times.dpd, vpninfo->ssl_times.keepalive);
-	vpn_progress(vpninfo, PRG_DEBUG, _("CSTP Ciphersuite: %s\n"),
-		     openconnect_get_cstp_cipher(vpninfo));
 
 	monitor_fd_new(vpninfo, ssl);
 

gnutls-dtls.c

@@ -35,9 +35,6 @@
 #include <gnutls/dtls.h>
 #include "gnutls.h"
 
-#if GNUTLS_VERSION_NUMBER < 0x030200
-# define GNUTLS_DTLS1_2 202
-#endif
 #if GNUTLS_VERSION_NUMBER < 0x030400
 # define GNUTLS_CIPHER_CHACHA20_POLY1305 23
 #endif
@@ -121,7 +118,7 @@ void gather_dtls_ciphers(struct openconnect_info *vpninfo, struct oc_text_buf *b
 
 	buf_append(buf, "PSK-NEGOTIATE");
 
-	ret = gnutls_priority_init(&cache, vpninfo->gnutls_prio, NULL);
+	ret = gnutls_priority_init(&cache, vpninfo->ciphersuite_config, NULL);
 	if (ret < 0) {
 		buf->error = -EIO;
 		return;
@@ -192,7 +189,7 @@ static int start_dtls_psk_handshake(struct openconnect_info *vpninfo, int dtls_f
 	}
 
 	prio = buf_alloc();
-	buf_append(prio, "%s:-VERS-TLS-ALL:+VERS-DTLS-ALL:-KX-ALL:+PSK", vpninfo->gnutls_prio);
+	buf_append(prio, "%s:-VERS-TLS-ALL:+VERS-DTLS-ALL:-KX-ALL:+PSK", vpninfo->ciphersuite_config);
 	if (buf_error(prio)) {
 		vpn_progress(vpninfo, PRG_ERR,
 			     _("Failed to generate DTLS priority string\n"));

gnutls.c

@@ -75,6 +75,17 @@ static int gnutls_pin_callback(void *priv, int attempt, const char *uri,
 	(GNUTLS_VERSION_NUMBER >= ( ((a) << 16) + ((b) << 8) + (c) ) || \
 	 gnutls_check_version(#a "." #b "." #c)))
 
+static char tls_library_version[32] = "";
+
+const char *openconnect_get_tls_library_version()
+{
+	if (!*tls_library_version) {
+		snprintf(tls_library_version, sizeof(tls_library_version), "GnuTLS %s",
+		         gnutls_check_version(NULL));
+	}
+	return tls_library_version;
+}
+
 /* Helper functions for reading/writing lines over SSL. */
 static int _openconnect_gnutls_write(gnutls_session_t ses, int fd, struct openconnect_info *vpninfo, char *buf, size_t len)
 {
@@ -526,33 +537,6 @@ static int load_pkcs12_certificate(struct openconnect_info *vpninfo,
 	return 0;
 }
 
-/* Older versions of GnuTLS didn't actually bother to check this, so we'll
-   do it for them. Is there a bug reference for this? Or just the git commit
-   reference (c1ef7efb in master, 5196786c in gnutls_3_0_x-2)? */
-static int check_issuer_sanity(gnutls_x509_crt_t cert, gnutls_x509_crt_t issuer)
-{
-#if GNUTLS_VERSION_NUMBER > 0x030014
-	return 0;
-#else
-	unsigned char id1[512], id2[512];
-	size_t id1_size = 512, id2_size = 512;
-	int err;
-
-	err = gnutls_x509_crt_get_authority_key_id(cert, id1, &id1_size, NULL);
-	if (err)
-		return 0;
-
-	err = gnutls_x509_crt_get_subject_key_id(issuer, id2, &id2_size, NULL);
-	if (err)
-		return 0;
-	if (id1_size == id2_size && !memcmp(id1, id2, id1_size))
-		return 0;
-
-	/* EEP! */
-	return -EIO;
-#endif
-}
-
 static int count_x509_certificates(gnutls_datum_t *datum)
 {
 	int count = 0;
@@ -1613,8 +1597,7 @@ static int load_certificate(struct openconnect_info *vpninfo)
 
 		for (i = 0; i < nr_extra_certs; i++) {
 			if (extra_certs[i] &&
-			    gnutls_x509_crt_check_issuer(last_cert, extra_certs[i]) &&
-			    !check_issuer_sanity(last_cert, extra_certs[i]))
+			    gnutls_x509_crt_check_issuer(last_cert, extra_certs[i]))
 				break;
 		}
 
@@ -1627,16 +1610,6 @@ static int load_certificate(struct openconnect_info *vpninfo)
 			/* Look for it in the system trust cafile too. */
 			err = gnutls_certificate_get_issuer(vpninfo->https_cred,
 							    last_cert, &issuer, 0);
-			/* The check_issuer_sanity() function works fine as a workaround where
-			   it was used above, but when gnutls_certificate_get_issuer() returns
-			   a bogus cert, there's nothing we can do to fix it up. We don't get
-			   to iterate over all the available certs like we can over our own
-			   list. */
-			if (!err && check_issuer_sanity(last_cert, issuer)) {
-				vpn_progress(vpninfo, PRG_ERR,
-					     _("WARNING: GnuTLS returned incorrect issuer certs; authentication may fail!\n"));
-				break;
-			}
 			free_issuer = 0;
 
 #ifdef HAVE_P11KIT
@@ -2230,24 +2203,26 @@ int openconnect_open_https(struct openconnect_info *vpninfo)
 	* 28065ce3896b1b0f87972d0bce9b17641ebb69b9
 	*/
 
+        if (!strlen(vpninfo->ciphersuite_config)) {
 #ifdef DEFAULT_PRIO
-	default_prio = DEFAULT_PRIO ":%COMPAT";
+		default_prio = DEFAULT_PRIO ":%COMPAT";
 #else
-	/* GnuTLS 3.5.19 and onward refuse to negotiate AES-CBC-HMAC-SHA256
-	 * by default but some Cisco servers can't do anything better, so
-	 * explicitly add '+SHA256' to allow it. Yay Cisco. */
-	default_prio = "NORMAL:-VERS-SSL3.0:+SHA256:%COMPAT";
+		/* GnuTLS 3.5.19 and onward refuse to negotiate AES-CBC-HMAC-SHA256
+		 * by default but some Cisco servers can't do anything better, so
+		 * explicitly add '+SHA256' to allow it. Yay Cisco. */
+		default_prio = "NORMAL:-VERS-SSL3.0:+SHA256:%COMPAT";
 #endif
 
-	snprintf(vpninfo->gnutls_prio, sizeof(vpninfo->gnutls_prio), "%s%s%s",
-		 default_prio, vpninfo->pfs?":-RSA":"", vpninfo->no_tls13?":-VERS-TLS1.3":"");
+		snprintf(vpninfo->ciphersuite_config, sizeof(vpninfo->ciphersuite_config), "%s%s%s",
+		         default_prio, vpninfo->pfs?":-RSA":"", vpninfo->no_tls13?":-VERS-TLS1.3":"");
+        }
 
 	err = gnutls_priority_set_direct(vpninfo->https_sess,
-					 vpninfo->gnutls_prio, NULL);
+					 vpninfo->ciphersuite_config, NULL);
 	if (err) {
 		vpn_progress(vpninfo, PRG_ERR,
-			     _("Failed to set TLS priority string (\"%s\"): %s\n"),
-			     vpninfo->gnutls_prio, gnutls_strerror(err));
+			     _("Failed to set GnuTLS priority string (\"%s\"): %s\n"),
+			     vpninfo->ciphersuite_config, gnutls_strerror(err));
 		gnutls_deinit(vpninfo->https_sess);
 		vpninfo->https_sess = NULL;
 		closesocket(ssl_sock);
@@ -2270,9 +2245,6 @@ int openconnect_open_https(struct openconnect_info *vpninfo)
 	if (err)
 		return err;
 
-	gnutls_free(vpninfo->cstp_cipher);
-	vpninfo->cstp_cipher = get_gnutls_cipher(vpninfo->https_sess);
-
 	vpninfo->ssl_fd = ssl_sock;
 
 	vpninfo->ssl_read = openconnect_gnutls_read;
@@ -2330,12 +2302,15 @@ int cstp_handshake(struct openconnect_info *vpninfo, unsigned init)
 		}
 	}
 
+	gnutls_free(vpninfo->cstp_cipher);
+	vpninfo->cstp_cipher = get_gnutls_cipher(vpninfo->https_sess);
+
 	if (init) {
-		vpn_progress(vpninfo, PRG_INFO, _("Connected to HTTPS on %s\n"),
-			     vpninfo->hostname);
+		vpn_progress(vpninfo, PRG_INFO, _("Connected to HTTPS on %s with ciphersuite %s\n"),
+			     vpninfo->hostname, vpninfo->cstp_cipher);
 	} else {
-		vpn_progress(vpninfo, PRG_INFO, _("Renegotiated SSL on %s\n"),
-			     vpninfo->hostname);
+		vpn_progress(vpninfo, PRG_INFO, _("Renegotiated SSL on %s with ciphersuite %s\n"),
+			     vpninfo->hostname, vpninfo->cstp_cipher);
 	}
 
 	return 0;
@@ -2381,15 +2356,7 @@ int openconnect_init_ssl(void)
 
 char *get_gnutls_cipher(gnutls_session_t session)
 {
-	char *str;
-#if GNUTLS_VERSION_NUMBER > 0x03010a
-	str = gnutls_session_get_desc(session);
-#else
-	str = gnutls_strdup(gnutls_cipher_suite_get_name(
-		gnutls_kx_get(session), gnutls_cipher_get(session),
-		gnutls_mac_get(session)));
-#endif
-	return str;
+	return gnutls_session_get_desc(session);
 }
 
 int openconnect_sha1(unsigned char *result, void *data, int datalen)
@@ -2657,7 +2624,7 @@ void *establish_eap_ttls(struct openconnect_info *vpninfo)
 	gnutls_credentials_set(ttls_sess, GNUTLS_CRD_CERTIFICATE, vpninfo->https_cred);
 
 	err = gnutls_priority_set_direct(ttls_sess,
-				   vpninfo->gnutls_prio, NULL);
+				   vpninfo->ciphersuite_config, NULL);
 
 	err = gnutls_handshake(ttls_sess);
 	if (!err) {

libopenconnect.map.in

@@ -110,6 +110,7 @@ OPENCONNECT_5_6 {
 
 OPENCONNECT_PRIVATE {
  global: @SYMVER_TIME@ @SYMVER_GETLINE@ @SYMVER_JAVA@ @SYMVER_ASPRINTF@ @SYMVER_VASPRINTF@ @SYMVER_WIN32_STRERROR@
+	openconnect_get_tls_library_version;
 	openconnect_fopen_utf8;
 	openconnect_open_utf8;
 	openconnect_sha1;

library.c

@@ -389,13 +389,19 @@ void openconnect_vpninfo_free(struct openconnect_info *vpninfo)
 	free(vpninfo->ifname);
 	free(vpninfo->dtls_cipher);
 	free(vpninfo->peer_cert_hash);
-#if defined(OPENCONNECT_OPENSSL) && defined (HAVE_BIO_METH_FREE)
+#if defined(OPENCONNECT_OPENSSL)
+	free(vpninfo->cstp_cipher);
+#if defined(HAVE_BIO_METH_FREE)
 	if (vpninfo->ttls_bio_meth)
 		BIO_meth_free(vpninfo->ttls_bio_meth);
+#endif
+#ifdef HAVE_DTLS
+	free(vpninfo->dtls_cipher_desc);
+#endif
 #elif defined(OPENCONNECT_GNUTLS)
-	gnutls_free(vpninfo->cstp_cipher); /* In OpenSSL this is const */
+	gnutls_free(vpninfo->cstp_cipher);
 #ifdef HAVE_DTLS
-	gnutls_free(vpninfo->gnutls_dtls_cipher);
+	gnutls_free(vpninfo->dtls_cipher_desc);
 #endif
 #endif
 	free(vpninfo->dtls_addr);
@@ -1010,23 +1016,27 @@ const char *openconnect_get_dtls_compression(struct openconnect_info * vpninfo)
 
 const char *openconnect_get_dtls_cipher(struct openconnect_info *vpninfo)
 {
+	if (vpninfo->dtls_state != DTLS_CONNECTED || !vpninfo->dtls_ssl) {
 #if defined(OPENCONNECT_GNUTLS)
-	if (vpninfo->dtls_state != DTLS_CONNECTED) {
-		gnutls_free(vpninfo->gnutls_dtls_cipher);
-		vpninfo->gnutls_dtls_cipher = NULL;
+		gnutls_free(vpninfo->dtls_cipher_desc);
+#else
+		free(vpninfo->dtls_cipher_desc);
+#endif
+		vpninfo->dtls_cipher_desc = NULL;
 		return NULL;
 	}
 	/* in DTLS rehandshakes don't switch the ciphersuite as only
 	 * one is enabled. */
-	if (vpninfo->gnutls_dtls_cipher == NULL)
-		vpninfo->gnutls_dtls_cipher = get_gnutls_cipher(vpninfo->dtls_ssl);
-	return vpninfo->gnutls_dtls_cipher;
+	if (vpninfo->dtls_cipher_desc == NULL) {
+#if defined(OPENCONNECT_GNUTLS)
+        vpninfo->dtls_cipher_desc = get_gnutls_cipher(vpninfo->dtls_ssl);
 #else
-	if (vpninfo->dtls_ssl)
-		return SSL_get_cipher(vpninfo->dtls_ssl);
-	else
-		return NULL;
+		if (asprintf(&vpninfo->dtls_cipher_desc, "%s-%s",
+		             SSL_get_version(vpninfo->dtls_ssl), SSL_get_cipher_name(vpninfo->dtls_ssl)) < 0)
+			return NULL;
 #endif
+	}
+    return vpninfo->dtls_cipher_desc;
 }
 
 int openconnect_set_csd_environ(struct openconnect_info *vpninfo,

main.c

@@ -156,6 +156,7 @@ enum {
 	OPT_COOKIE_ON_STDIN,
 	OPT_CSD_USER,
 	OPT_CSD_WRAPPER,
+	OPT_CIPHERSUITES,
 	OPT_DISABLE_IPV6,
 	OPT_DTLS_CIPHERS,
 	OPT_DTLS12_CIPHERS,
@@ -280,6 +281,9 @@ static const struct option long_options[] = {
 	OPTION("form-entry", 1, 'F'),
 #ifdef OPENCONNECT_GNUTLS
 	OPTION("gnutls-debug", 1, OPT_GNUTLS_DEBUG),
+	OPTION("gnutls-priority", 1, OPT_CIPHERSUITES),
+#elif defined(OPENCONNECT_OPENSSL)
+	OPTION("openssl-ciphers", 1, OPT_CIPHERSUITES),
 #endif
 	OPTION(NULL, 0, 0)
 };
@@ -596,11 +600,7 @@ static void print_build_opts(void)
 {
 	const char *comma = ", ", *sep = comma + 1;
 
-#if defined(OPENCONNECT_OPENSSL)
-	printf(_("Using OpenSSL. Features present:"));
-#elif defined(OPENCONNECT_GNUTLS)
-	printf(_("Using GnuTLS. Features present:"));
-#endif
+	printf(_("Using %s. Features present:"), openconnect_get_tls_library_version());
 
 	if (openconnect_has_tss_blob_support()) {
 		printf("%sTPM", sep);
@@ -1505,6 +1505,19 @@ int main(int argc, char **argv)
 			gnutls_global_set_log_function(oc_gnutls_log_func);
 			break;
 #endif
+		case OPT_CIPHERSUITES:
+			fprintf(stderr,
+#ifdef OPENCONNECT_GNUTLS
+			        _("WARNING: You specified --gnutls-priority. This should not be\n"
+			          "         necessary; please report cases where a priority string\n"
+#elif defined(OPENCONNECT_OPENSSL)
+			        _("WARNING: You specified --openssl-ciphers. This should not be\n"
+			          "         necessary; please report cases where a cipher list\n"
+#endif
+			          "         override is necessary to connect to a server\n"
+			          "         to <openconnect-devel@lists.infradead.org>.\n"));
+			strncpy(vpninfo->ciphersuite_config, config_arg, sizeof(vpninfo->ciphersuite_config) - 1);
+			break;
 		default:
 			usage();
 		}

openconnect-internal.h

@@ -523,14 +523,14 @@ struct openconnect_info {
 	gnutls_certificate_credentials_t https_cred;
 	gnutls_psk_client_credentials_t psk_cred;
 	char local_cert_md5[MD5_SIZE * 2 + 1]; /* For CSD */
-	char gnutls_prio[256];
 #ifdef HAVE_TROUSERS
 	struct oc_tpm1_ctx *tpm1;
 #endif
 #ifdef HAVE_TSS2
 	struct oc_tpm2_ctx *tpm2;
 #endif
 #endif /* OPENCONNECT_GNUTLS */
+	char ciphersuite_config[256];
 	struct oc_text_buf *ttls_pushbuf;
 	uint8_t ttls_eap_ident;
 	unsigned char *ttls_recvbuf;
@@ -573,9 +573,9 @@ struct openconnect_info {
 	   NULL or not or pass it to DTLS_SEND/DTLS_RECV. This way we
 	   have fewer ifdefs and accessor macros for it. */
 	gnutls_session_t dtls_ssl;
-	char *gnutls_dtls_cipher; /* cached for openconnect_get_dtls_cipher() */
 #endif
-	char *cstp_cipher;
+	char *cstp_cipher; /* library-dependent description of TLS cipher */
+	char *dtls_cipher_desc; /* library-dependent description of DTLS cipher, cached for openconnect_get_dtls_cipher() */
 
 	int dtls_state;
 	int dtls_need_reconnect;
@@ -587,8 +587,9 @@ struct openconnect_info {
 
 	uint32_t ift_seq;
 
-	int cisco_dtls12;
-	char *dtls_cipher;
+	int cisco_dtls12; /* If Cisco server sent X-DTLS12-CipherSuite header, rather than X-DTLS-CipherSuite */
+	char *dtls_cipher; /* Value of aforementioned header (PSK-NEGOTIATE, or an OpenSSL cipher name) */
+
 	char *vpnc_script;
 #ifndef _WIN32
 	int uid_csd_given;
@@ -997,6 +998,7 @@ int decrypt_esp_packet(struct openconnect_info *vpninfo, struct esp *esp, struct
 int encrypt_esp_packet(struct openconnect_info *vpninfo, struct pkt *pkt, int crypt_len);
 
 /* {gnutls,openssl}.c */
+const char *openconnect_get_tls_library_version();
 int ssl_nonblock_read(struct openconnect_info *vpninfo, void *buf, int maxlen);
 int ssl_nonblock_write(struct openconnect_info *vpninfo, void *buf, int buflen);
 int openconnect_open_https(struct openconnect_info *vpninfo);

openssl-dtls.c

@@ -603,8 +603,8 @@ int dtls_try_handshake(struct openconnect_info *vpninfo)
 
 		vpninfo->dtls_state = DTLS_CONNECTED;
 		vpn_progress(vpninfo, PRG_INFO,
-			     _("Established DTLS connection (using OpenSSL). Ciphersuite %s.\n"),
-			     SSL_get_cipher(vpninfo->dtls_ssl));
+			     _("Established DTLS connection (using OpenSSL). Ciphersuite %s-%s.\n"),
+			     SSL_get_version(vpninfo->dtls_ssl), SSL_get_cipher(vpninfo->dtls_ssl));
 
 		c = openconnect_get_dtls_compression(vpninfo);
 		if (c) {