Changeset 792a93b for lib/ssl_gnutls.c

Timestamp:

2011-12-23T12:44:08Z (12 years ago)

Author:

Wilmer van der Gaast <wilmer@…>

Branches:

master

Children:

200e151

Parents:

2d93a51e (diff), 41658da (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merging SSL certificate verification for GnuTLS, with help from AopicieR.

File:

• lib/ssl_gnutls.c (modified) (13 diffs)

lib/ssl_gnutls.c

@@ -25 +25 @@
 
 #include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
 #include <gcrypt.h>
 #include <fcntl.h>
@@ -32 +33 @@
 #include "sock.h"
 #include "stdlib.h"
+#include "bitlbee.h"
 
 int ssl_errno = 0;
@@ -54 +56 @@
         gboolean established;
         int inpa;
+        char *hostname;
+        gboolean verify;
         
         gnutls_session session;
@@ -74 +78 @@
 }
 
-void *ssl_connect( char *host, int port, ssl_input_function func, gpointer data )
+void *ssl_connect( char *host, int port, gboolean verify, ssl_input_function func, gpointer data )
 {
         struct scd *conn = g_new0( struct scd, 1 );
@@ -82 +86 @@
         conn->data = data;
         conn->inpa = -1;
+        conn->hostname = g_strdup( host );
+        conn->verify = verify && global.conf->cafile;
         
         if( conn->fd < 0 )
@@ -92 +98 @@
 }
 
-void *ssl_starttls( int fd, ssl_input_function func, gpointer data )
+void *ssl_starttls( int fd, char *hostname, gboolean verify, ssl_input_function func, gpointer data )
 {
         struct scd *conn = g_new0( struct scd, 1 );
@@ -100 +106 @@
         conn->data = data;
         conn->inpa = -1;
+        conn->hostname = hostname;
+        
+        /* For now, SSL verification is globally enabled by setting the cafile
+           setting in bitlbee.conf. Commented out by default because probably
+           not everyone has this file in the same place and plenty of folks
+           may not have the cert of their private Jabber server in it. */
+        conn->verify = verify && global.conf->cafile;
         
         /* This function should be called via a (short) timeout instead of
@@ -122 +135 @@
 }
 
+static int verify_certificate_callback( gnutls_session_t session )
+{
+        unsigned int status;
+        const gnutls_datum_t *cert_list;
+        unsigned int cert_list_size;
+        int gnutlsret;
+        int verifyret = 0;
+        gnutls_x509_crt_t cert;
+        const char *hostname;
+        
+        hostname = gnutls_session_get_ptr(session );
+
+        gnutlsret = gnutls_certificate_verify_peers2( session, &status );
+        if( gnutlsret < 0 )
+                return VERIFY_CERT_ERROR;
+
+        if( status & GNUTLS_CERT_INVALID )
+                verifyret |= VERIFY_CERT_INVALID;
+
+        if( status & GNUTLS_CERT_REVOKED )
+                verifyret |= VERIFY_CERT_REVOKED;
+
+        if( status & GNUTLS_CERT_SIGNER_NOT_FOUND )
+                verifyret |= VERIFY_CERT_SIGNER_NOT_FOUND;
+
+        if( status & GNUTLS_CERT_SIGNER_NOT_CA )
+                verifyret |= VERIFY_CERT_SIGNER_NOT_CA;
+
+        if( status & GNUTLS_CERT_INSECURE_ALGORITHM )
+                verifyret |= VERIFY_CERT_INSECURE_ALGORITHM;
+
+        if( status & GNUTLS_CERT_NOT_ACTIVATED )
+                verifyret |= VERIFY_CERT_NOT_ACTIVATED;
+
+        if( status & GNUTLS_CERT_EXPIRED )
+                verifyret |= VERIFY_CERT_EXPIRED;
+
+        /* The following check is already performed inside 
+         * gnutls_certificate_verify_peers2, so we don't need it.
+
+         * if( gnutls_certificate_type_get( session ) != GNUTLS_CRT_X509 )
+         * return GNUTLS_E_CERTIFICATE_ERROR;
+         */
+
+        if( gnutls_x509_crt_init( &cert ) < 0 )
+                return VERIFY_CERT_ERROR;
+
+        cert_list = gnutls_certificate_get_peers( session, &cert_list_size );
+        if( cert_list == NULL || gnutls_x509_crt_import( cert, &cert_list[0], GNUTLS_X509_FMT_DER ) < 0 )
+                return VERIFY_CERT_ERROR;
+
+        if( !gnutls_x509_crt_check_hostname( cert, hostname ) )
+        {
+                verifyret |= VERIFY_CERT_INVALID;
+                verifyret |= VERIFY_CERT_WRONG_HOSTNAME;
+        }
+
+        gnutls_x509_crt_deinit( cert );
+
+        return verifyret;
+}
+
+char *ssl_verify_strerror( int code )
+{
+        GString *ret = g_string_new( "" );
+        
+        if( code & VERIFY_CERT_REVOKED )
+                g_string_append( ret, "certificate has been revoked, " );
+        if( code & VERIFY_CERT_SIGNER_NOT_FOUND )
+                g_string_append( ret, "certificate hasn't got a known issuer, " );
+        if( code & VERIFY_CERT_SIGNER_NOT_CA )
+                g_string_append( ret, "certificate's issuer is not a CA, " );
+        if( code & VERIFY_CERT_INSECURE_ALGORITHM )
+                g_string_append( ret, "certificate uses an insecure algorithm, " );
+        if( code & VERIFY_CERT_NOT_ACTIVATED )
+                g_string_append( ret, "certificate has not been activated, " );
+        if( code & VERIFY_CERT_EXPIRED )
+                g_string_append( ret, "certificate has expired, " );
+        if( code & VERIFY_CERT_WRONG_HOSTNAME )
+                g_string_append( ret, "certificate hostname mismatch, " );
+        
+        if( ret->len == 0 )
+        {
+                g_string_free( ret, TRUE );
+                return NULL;
+        }
+        else
+        {
+                g_string_truncate( ret, ret->len - 2 );
+                return g_string_free( ret, FALSE );
+        }
+}
+
 static gboolean ssl_connected( gpointer data, gint source, b_input_condition cond )
 {
@@ -128 +234 @@
         if( source == -1 )
         {
-                conn->func( conn->data, NULL, cond );
+                conn->func( conn->data, 0, NULL, cond );
                 g_free( conn );
                 return FALSE;
@@ -136 +242 @@
         
         gnutls_certificate_allocate_credentials( &conn->xcred );
+        if( conn->verify && global.conf->cafile )
+        {
+                gnutls_certificate_set_x509_trust_file( conn->xcred, global.conf->cafile, GNUTLS_X509_FMT_PEM );
+                gnutls_certificate_set_verify_flags( conn->xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT );
+        }
+
         gnutls_init( &conn->session, GNUTLS_CLIENT );
+        if( conn->verify )
+                gnutls_session_set_ptr( conn->session, (void *) conn->hostname );
 #if GNUTLS_VERSION_NUMBER < 0x020c00
         gnutls_transport_set_lowat( conn->session, 0 );
@@ -152 +266 @@
 {
         struct scd *conn = data;
-        int st;
+        int st, stver;
         
         if( ( st = gnutls_handshake( conn->session ) ) < 0 )
@@ -163 +277 @@
                 else
                 {
-                        conn->func( conn->data, NULL, cond );
+                        conn->func( conn->data, 0, NULL, cond );
                         
                         gnutls_deinit( conn->session );
@@ -174 +288 @@
         else
         {
-                /* For now we can't handle non-blocking perfectly everywhere... */
-                sock_make_blocking( conn->fd );
+                if( conn->verify && ( stver = verify_certificate_callback( conn->session ) ) != 0 )
+                {
+                        conn->func( conn->data, stver, NULL, cond );
+
+                        gnutls_deinit( conn->session );
+                        gnutls_certificate_free_credentials( conn->xcred );
+                        closesocket( conn->fd );
+
+                        g_free( conn );
+                }
+                else
+                {
+                        /* For now we can't handle non-blocking perfectly everywhere... */
+                        sock_make_blocking( conn->fd );
                 
-                conn->established = TRUE;
-                conn->func( conn->data, conn, cond );
+                        conn->established = TRUE;
+                        conn->func( conn->data, 0, conn, cond );
+                }
         }