gst/gstregistrybinary.*: Add crc32 checksum to the binary registry file and check this before accepting a registry file.

Original commit message from CVS:
* gst/gstregistrybinary.c: (_gst_crc32),
(gst_registry_binary_write),
(gst_registry_binary_initialize_magic),
(gst_registry_binary_write_cache),
(gst_registry_binary_check_magic),
(gst_registry_binary_read_cache):
* gst/gstregistrybinary.h:
Add crc32 checksum to the binary registry file and check this before
accepting a registry file.
Also free the data list when writing to the registry file fails.

ChangeLog

@@ -1,3 +1,17 @@
+2008-04-16  Sebastian Dröge  <slomo@circular-chaos.org>
+
+	* gst/gstregistrybinary.c: (_gst_crc32),
+	(gst_registry_binary_write),
+	(gst_registry_binary_initialize_magic),
+	(gst_registry_binary_write_cache),
+	(gst_registry_binary_check_magic),
+	(gst_registry_binary_read_cache):
+	* gst/gstregistrybinary.h:
+	Add crc32 checksum to the binary registry file and check this before
+	accepting a registry file.
+
+	Also free the data list when writing to the registry file fails.
+
 2008-04-16  Sebastian Dröge  <slomo@circular-chaos.org>
 
 	* gst/gstregistrybinary.c: (gst_registry_binary_save_feature),

gst/gstregistrybinary.c

@@ -22,14 +22,12 @@
  */
 
 /* FIXME:
- * - Add random key to libgstreamer during build and only accept registry,
- *   if key matches (or is the version check enough)
  * - keep registry binary blob and reference strings
  *   - don't free/unmmap contents when leaving gst_registry_binary_read_cache()
  *     - free at gst_deinit() / _priv_gst_registry_cleanup() ?
  *   - GstPlugin:
  *     - GST_PLUGIN_FLAG_CONST
- *   -GstPluginFeature, GstIndexFactory, GstElementFactory
+ *   - GstPluginFeature, GstIndexFactory, GstElementFactory
  *     - needs Flags (GST_PLUGIN_FEATURE_FLAG_CONST)
  *     - can we turn loaded into flag?
  * - why do we collect a list of binary chunks and not write immediately
@@ -37,7 +35,6 @@
  *     in parent chunk
  * - need more robustness
  *   - don't parse beyond mem-block size
- *   - include md5-sum ?
  */
 
 #ifdef HAVE_CONFIG_H
@@ -93,6 +90,126 @@
 #define align(_ptr)          _ptr += (( alignment(_ptr) == 0) ? 0 : ALIGNMENT-alignment(_ptr))
 
 
+/* CRC32 calculation */
+
+/* The crc32() function is copyrighted and licensed as specified below.
+ * This only applies to this single function:
+
+  crc32.c -- compute the CRC-32 of a data stream
+  Copyright (C) 1995-1998 Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+*/
+
+/* Changes for gstreamer:
+ * - Changed to use GLib data types
+ * - Change function name to _gst_crc32
+ */
+
+/* ========================================================================
+ * Table of CRC-32's of all single-byte values (made by make_crc_table)
+ */
+static const guint32 crc_table[256] = {
+  0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+  0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+  0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+  0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+  0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+  0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+  0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+  0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+  0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+  0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+  0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+  0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+  0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+  0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+  0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+  0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+  0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+  0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+  0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+  0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+  0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+  0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+  0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+  0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+  0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+  0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+  0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+  0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+  0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+  0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+  0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+  0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+  0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+  0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+  0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+  0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+  0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+  0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+  0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+  0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+  0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+  0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+  0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+  0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+  0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+  0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+  0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+  0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+  0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+  0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+  0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+  0x2d02ef8dL
+};
+
+/* ========================================================================= */
+#define DO1(buf) crc = crc_table[((gint)crc ^ (*buf++)) & 0xff] ^ (crc >> 8);
+#define DO2(buf)  DO1(buf); DO1(buf);
+#define DO4(buf)  DO2(buf); DO2(buf);
+#define DO8(buf)  DO4(buf); DO4(buf);
+
+/* ========================================================================= */
+static guint32
+_gst_crc32 (guint32 crc, const gchar * buf, guint len)
+{
+  if (buf == NULL)
+    return 0L;
+  crc = crc ^ 0xffffffffL;
+  while (len >= 8) {
+    DO8 (buf);
+    len -= 8;
+  }
+  if (len)
+    do {
+      DO1 (buf);
+    } while (--len);
+  return crc ^ 0xffffffffL;
+}
+
+#undef DO1
+#undef DO2
+#undef DO4
+#undef DO8
+
 /* Registry saving */
 
 /*
@@ -104,7 +221,8 @@
  */
 inline static gboolean
 gst_registry_binary_write (GstRegistry * registry, const void *mem,
-    const gssize size, unsigned long *file_position, gboolean align)
+    const gssize size, unsigned long *file_position, gboolean align,
+    guint32 * crc32)
 {
   gchar padder[ALIGNMENT] = { 0, };
   int padsize = 0;
@@ -116,6 +234,8 @@ gst_registry_binary_write (GstRegistry * registry, const void *mem,
       GST_ERROR ("Failed to write binary registry padder");
       return FALSE;
     }
+    if (padsize > 0)
+      *crc32 = _gst_crc32 (*crc32, padder, padsize);
     *file_position = *file_position + padsize;
   }
 
@@ -123,6 +243,9 @@ gst_registry_binary_write (GstRegistry * registry, const void *mem,
     GST_ERROR ("Failed to write binary registry element");
     return FALSE;
   }
+  if (size > 0)
+    *crc32 = _gst_crc32 (*crc32, mem, size);
+
   *file_position = *file_position + size;
   return TRUE;
 }
@@ -144,6 +267,9 @@ gst_registry_binary_initialize_magic (GstBinaryRegistryMagic * m)
     GST_ERROR ("Failed to write magic to the registry magic structure");
     return FALSE;
   }
+
+  m->crc32 = 0;
+
   return TRUE;
 }
 
@@ -458,8 +584,7 @@ gst_registry_binary_write_cache (GstRegistry * registry, const char *location)
 {
   GList *walk;
   gchar *tmp_location;
-  GstBinaryRegistryMagic *magic;
+  GstBinaryRegistryMagic magic;
-  GstBinaryChunk *magic_chunk;
   GList *to_write = NULL;
   unsigned long file_position = 0;
 
@@ -488,16 +613,9 @@ gst_registry_binary_write_cache (GstRegistry * registry, const char *location)
     }
   }
 
-  magic = g_malloc (sizeof (GstBinaryRegistryMagic));
+  if (!gst_registry_binary_initialize_magic (&magic))
-  if (!gst_registry_binary_initialize_magic (magic))
     goto fail;
 
-  magic_chunk = g_malloc (sizeof (GstBinaryChunk));
-  magic_chunk->data = magic;
-  magic_chunk->size = sizeof (GstBinaryRegistryMagic);
-  magic_chunk->flags = GST_BINARY_REGISTRY_FLAG_NONE;
-  magic_chunk->align = TRUE;
-
   /* iterate trough the list of plugins and fit them into binary structures */
   for (walk = registry->plugins; walk; walk = g_list_next (walk)) {
     GstPlugin *plugin = GST_PLUGIN (walk->data);
@@ -521,28 +639,44 @@ gst_registry_binary_write_cache (GstRegistry * registry, const char *location)
           plugin->filename);
     }
   }
-  to_write = g_list_prepend (to_write, magic_chunk);
 
   GST_INFO ("Writing binary registry cache");
 
+  /* write magic */
+  if (write (registry->cache_file, &magic,
+          sizeof (GstBinaryRegistryMagic)) != sizeof (GstBinaryRegistryMagic)) {
+    GST_ERROR ("Failed to write binary registry magic");
+    goto fail_free_list;
+  }
+  file_position += sizeof (GstBinaryRegistryMagic);
+
   /* write out data chunks */
   for (walk = to_write; walk; walk = g_list_next (walk)) {
     GstBinaryChunk *cur = walk->data;
 
     if (!gst_registry_binary_write (registry, cur->data, cur->size,
-            &file_position, cur->align)) {
+            &file_position, cur->align, &magic.crc32)) {
       if (!(cur->flags & GST_BINARY_REGISTRY_FLAG_CONST))
         g_free (cur->data);
       g_free (cur);
-      g_list_free (to_write);
+      walk->data = NULL;
-      goto fail;
+      goto fail_free_list;
     }
     if (!(cur->flags & GST_BINARY_REGISTRY_FLAG_CONST))
       g_free (cur->data);
     g_free (cur);
+    walk->data = NULL;
   }
   g_list_free (to_write);
 
+  if (lseek (registry->cache_file, 0, SEEK_SET) != 0) {
+    GST_ERROR ("Seeking to rewrite the binary registry CRC32 failed");
+  } else {
+    if (write (registry->cache_file, &magic,
+            sizeof (GstBinaryRegistryMagic)) != sizeof (GstBinaryRegistryMagic))
+      GST_ERROR ("Failed to rewrite binary registry magic");
+  }
+
   if (close (registry->cache_file) < 0)
     goto close_failed;
 
@@ -561,6 +695,18 @@ gst_registry_binary_write_cache (GstRegistry * registry, const char *location)
   return TRUE;
 
   /* Errors */
+fail_free_list:
+  {
+    for (walk = to_write; walk; walk = g_list_next (walk)) {
+      GstBinaryChunk *cur = walk->data;
+
+      if (!(cur->flags & GST_BINARY_REGISTRY_FLAG_CONST))
+        g_free (cur->data);
+      g_free (cur);
+    }
+    g_list_free (to_write);
+    /* fall through */
+  }
 fail:
   {
     (void) close (registry->cache_file);
@@ -596,9 +742,10 @@ rename_failed:
  * date, -1 is a general failure.
  */
 static gint
-gst_registry_binary_check_magic (gchar ** in)
+gst_registry_binary_check_magic (gchar ** in, gsize size)
 {
   GstBinaryRegistryMagic *m;
+  guint32 crc32 = 0;
 
   align (*in);
   GST_DEBUG ("Reading/casting for GstBinaryRegistryMagic at address %p", *in);
@@ -625,6 +772,14 @@ gst_registry_binary_check_magic (gchar ** in)
         GST_MAGIC_BINARY_VERSION_STR, m->version);
     return -2;
   }
+
+  crc32 = _gst_crc32 (crc32, *in, size - sizeof (GstBinaryRegistryMagic));
+  if (crc32 != m->crc32) {
+    GST_WARNING ("Binary registry CRC32 different: 0x%x != 0x%x\n", crc32,
+        m->crc32);
+    return -1;
+  }
+
   return 0;
 }
 
@@ -939,7 +1094,7 @@ gst_registry_binary_read_cache (GstRegistry * registry, const char *location)
     goto Error;
   }
   /* check if header is valid */
-  if ((check_magic_result = gst_registry_binary_check_magic (&in)) < 0) {
+  if ((check_magic_result = gst_registry_binary_check_magic (&in, size)) < 0) {
 
     if (check_magic_result == -1)
       GST_ERROR

gst/gstregistrybinary.h

@@ -57,7 +57,7 @@
  * This _must_ be updated whenever the registry format changes,
  * we currently use the core version where this change happened.
  */
-#define GST_MAGIC_BINARY_VERSION_STR ("0.10.18.1")
+#define GST_MAGIC_BINARY_VERSION_STR ("0.10.18.2")
 
 /*
  * GST_MAGIC_BINARY_VERSION_LEN:
@@ -70,6 +70,7 @@ typedef struct _GstBinaryRegistryMagic
 {
   gchar magic[GST_MAGIC_BINARY_REGISTRY_LEN];
   gchar version[GST_MAGIC_BINARY_VERSION_LEN];
+  guint32 crc32;
 } GstBinaryRegistryMagic;
 
 /*