Componentize component_updater: Split crx_file code off into its own component.

CRX file code currently lives under extensions/. However, 
component_updater also uses them to package components. The 
CRX code should therefore live as its own component.

BUG=371463
TBR=blundell@chromium.org

Review URL: https://codereview.chromium.org/474633005

Cr-Commit-Position: refs/heads/master@{#289966}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289966 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 81 insertions, 0 deletions

diff --git a/components/crx_file/crx_file.cc b/components/crx_file/crx_file.cc
new file mode 100644
index 0000000..391d549
--- /dev/null
+++ b/components/crx_file/crx_file.cc
@@ -0,0 +1,81 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/crx_file/crx_file.h"
+
+namespace crx_file {
+
+namespace {
+
+// The current version of the crx format.
+static const uint32 kCurrentVersion = 2;
+
+// The current version of the crx diff format.
+static const uint32 kCurrentDiffVersion = 0;
+
+// The maximum size the crx parser will tolerate for a public key.
+static const uint32 kMaxPublicKeySize = 1 << 16;
+
+// The maximum size the crx parser will tolerate for a signature.
+static const uint32 kMaxSignatureSize = 1 << 16;
+
+}  // namespace
+
+// The magic string embedded in the header.
+const char kCrxFileHeaderMagic[] = "Cr24";
+const char kCrxDiffFileHeaderMagic[] = "CrOD";
+
+scoped_ptr<CrxFile> CrxFile::Parse(const CrxFile::Header& header,
+                                   CrxFile::Error* error) {
+  if (HeaderIsValid(header, error))
+    return scoped_ptr<CrxFile>(new CrxFile(header));
+  return scoped_ptr<CrxFile>();
+}
+
+scoped_ptr<CrxFile> CrxFile::Create(const uint32 key_size,
+                                    const uint32 signature_size,
+                                    CrxFile::Error* error) {
+  CrxFile::Header header;
+  memcpy(&header.magic, kCrxFileHeaderMagic, kCrxFileHeaderMagicSize);
+  header.version = kCurrentVersion;
+  header.key_size = key_size;
+  header.signature_size = signature_size;
+  if (HeaderIsValid(header, error))
+    return scoped_ptr<CrxFile>(new CrxFile(header));
+  return scoped_ptr<CrxFile>();
+}
+
+CrxFile::CrxFile(const Header& header) : header_(header) {
+}
+
+bool CrxFile::HeaderIsDelta(const CrxFile::Header& header) {
+  return !strncmp(kCrxDiffFileHeaderMagic, header.magic, sizeof(header.magic));
+}
+
+bool CrxFile::HeaderIsValid(const CrxFile::Header& header,
+                            CrxFile::Error* error) {
+  bool valid = false;
+  bool diffCrx = false;
+  if (!strncmp(kCrxDiffFileHeaderMagic, header.magic, sizeof(header.magic)))
+    diffCrx = true;
+  if (strncmp(kCrxFileHeaderMagic, header.magic, sizeof(header.magic)) &&
+      !diffCrx)
+    *error = kWrongMagic;
+  else if (header.version != kCurrentVersion
+      && !(diffCrx && header.version == kCurrentDiffVersion))
+    *error = kInvalidVersion;
+  else if (header.key_size > kMaxPublicKeySize)
+    *error = kInvalidKeyTooLarge;
+  else if (header.key_size == 0)
+    *error = kInvalidKeyTooSmall;
+  else if (header.signature_size > kMaxSignatureSize)
+    *error = kInvalidSignatureTooLarge;
+  else if (header.signature_size == 0)
+    *error = kInvalidSignatureTooSmall;
+  else
+    valid = true;
+  return valid;
+}
+
+}  // namespace crx_file