Diff: library/x509_crt.c

Revision:

2:bbdeda018a3c

Parent:

1:9ebc941037d5

--- a/library/x509_crt.c	Fri Sep 29 18:41:59 2017 +0100
+++ b/library/x509_crt.c	Fri Sep 29 19:50:30 2017 +0100
@@ -85,9 +85,11 @@
  */
 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
 {
-    /* Hashes from SHA-1 and above */
+#if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
+    /* Allow SHA-1 (weak, but still safe in controlled environments) */
     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
-    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_RIPEMD160 ) |
+#endif
+    /* Only SHA-2 hashes */
     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
@@ -746,14 +748,14 @@
         return( ret );
     }
 
-    crt->version++;
-
-    if( crt->version > 3 )
+    if( crt->version < 0 || crt->version > 2 )
     {
         mbedtls_x509_crt_free( crt );
         return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
     }
 
+    crt->version++;
+
     if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1,
                                   &crt->sig_md, &crt->sig_pk,
                                   &crt->sig_opts ) ) != 0 )
@@ -1144,7 +1146,10 @@
                                      p, (int) len - 1,
                                      NULL, NULL );
         if( w_ret == 0 )
-            return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
+        {
+            ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
+            goto cleanup;
+        }
 
         w_ret = mbedtls_x509_crt_parse_file( chain, filename );
         if( w_ret < 0 )
@@ -1157,6 +1162,7 @@
     if( GetLastError() != ERROR_NO_MORE_FILES )
         ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
 
+cleanup:
     FindClose( hFind );
 #else /* _WIN32 */
     int t_ret;
@@ -1169,13 +1175,13 @@
     if( dir == NULL )
         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
 
-#if defined(MBEDTLS_THREADING_PTHREAD)
+#if defined(MBEDTLS_THREADING_C)
     if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 )
     {
         closedir( dir );
         return( ret );
     }
-#endif
+#endif /* MBEDTLS_THREADING_C */
 
     while( ( entry = readdir( dir ) ) != NULL )
     {
@@ -1208,10 +1214,10 @@
 cleanup:
     closedir( dir );
 
-#if defined(MBEDTLS_THREADING_PTHREAD)
+#if defined(MBEDTLS_THREADING_C)
     if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 )
         ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
-#endif
+#endif /* MBEDTLS_THREADING_C */
 
 #endif /* _WIN32 */
 
@@ -2055,8 +2061,8 @@
     /* path_cnt is 0 for the first intermediate CA */
     if( 1 + path_cnt > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
     {
-        *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
-        return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
+        /* return immediately as the goal is to avoid unbounded recursion */
+        return( MBEDTLS_ERR_X509_FATAL_ERROR );
     }
 
     if( mbedtls_x509_time_is_past( &child->valid_to ) )
@@ -2200,10 +2206,13 @@
     mbedtls_x509_sequence *cur = NULL;
     mbedtls_pk_type_t pk_type;
 
+    *flags = 0;
+
     if( profile == NULL )
-        return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
-
-    *flags = 0;
+    {
+        ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
+        goto exit;
+    }
 
     if( cn != NULL )
     {
@@ -2278,7 +2287,7 @@
         ret = x509_crt_verify_top( crt, parent, ca_crl, profile,
                                    pathlen, selfsigned, flags, f_vrfy, p_vrfy );
         if( ret != 0 )
-            return( ret );
+            goto exit;
     }
     else
     {
@@ -2293,17 +2302,30 @@
             ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl, profile,
                                          pathlen, selfsigned, flags, f_vrfy, p_vrfy );
             if( ret != 0 )
-                return( ret );
+                goto exit;
         }
         else
         {
             ret = x509_crt_verify_top( crt, trust_ca, ca_crl, profile,
                                        pathlen, selfsigned, flags, f_vrfy, p_vrfy );
             if( ret != 0 )
-                return( ret );
+                goto exit;
         }
     }
 
+exit:
+    /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
+     * the SSL module for authmode optional, but non-zero return from the
+     * callback means a fatal error so it shouldn't be ignored */
+    if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
+        ret = MBEDTLS_ERR_X509_FATAL_ERROR;
+
+    if( ret != 0 )
+    {
+        *flags = (uint32_t) -1;
+        return( ret );
+    }
+
     if( *flags != 0 )
         return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );