crypto: add OpenPGP symmetric encryption for ChromeOS

This contains a basic implementation of OpenPGP (RFC 4880) symmetric
encryption and decryption. It's written specifically on top of OpenSSL,
which should suffice for the intended use case.

BUG=none
TEST=crypto_unittest

Review URL: http://codereview.chromium.org/7247005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@90633 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 45 insertions, 0 deletions

diff --git a/crypto/openpgp_symmetric_encryption.h b/crypto/openpgp_symmetric_encryption.h
new file mode 100644
index 0000000..d49d216
--- /dev/null
+++ b/crypto/openpgp_symmetric_encryption.h
@@ -0,0 +1,45 @@
+// Copyright (c) 2011 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.
+
+#ifndef CRYPTO_OPENPGP_SYMMETRIC_ENCRYPTION_H_
+#define CRYPTO_OPENPGP_SYMMETRIC_ENCRYPTION_H_
+#pragma once
+
+#include <string>
+
+#include "base/string_piece.h"
+
+namespace crypto {
+
+// OpenPGPSymmetricEncrytion implements enough of RFC 4880 to read and write
+// uncompressed, symmetrically encrypted data. You can create ciphertext
+// compatable with this code from the command line with:
+//    gpg --compress-algo=NONE --cipher-algo=AES -c
+//
+// Likewise, the output of this can be decrypted on the command line with:
+//    gpg < input
+class OpenPGPSymmetricEncrytion {
+ public:
+  enum Result {
+    OK,
+    UNKNOWN_CIPHER,  // you forgot to pass --cipher-algo=AES to gpg
+    UNKNOWN_HASH,
+    NOT_SYMMETRICALLY_ENCRYPTED,  // it's OpenPGP data, but not correct form
+    COMPRESSED,  // you forgot to pass --compress-algo=NONE
+    PARSE_ERROR,  // it's not OpenPGP data.
+    INTERNAL_ERROR,
+  };
+
+  static Result Decrypt(base::StringPiece encrypted,
+                        base::StringPiece passphrase,
+                        std::string *out);
+
+  static std::string Encrypt(base::StringPiece plaintext,
+                             base::StringPiece passphrase);
+};
+
+}  // namespace crypto
+
+#endif  // CRYPTO_OPENPGP_SYMMETRIC_ENCRYPTION_H_
+