Initial patch from Will.

src/platform/cryptohome/cryptohome_common.h

Index: src/platform/cryptohome/cryptohome_common.h
diff --git a/src/platform/cryptohome/cryptohome_common.h b/src/platform/cryptohome/cryptohome_common.h
new file mode 100644
index 0000000000000000000000000000000000000000..d6e0d37ab49007d3649492091bbab8b44f153e4d
--- /dev/null
+++ b/src/platform/cryptohome/cryptohome_common.h
@@ -0,0 +1,44 @@
+// Copyright (c) 2009-2010 The Chromium OS 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 CRYPTOHOME_COMMON_H_
+#define CRYPTOHOME_COMMON_H_
+
+extern "C" {
+#include <ecryptfs.h>
+}
+
+namespace cryptohome {
+
+// The default symmetric key size for cryptohome is the ecryptfs default
+#define CRYPTOHOME_DEFAULT_KEY_SIZE ECRYPTFS_MAX_KEY_BYTES
+#define CRYPTOHOME_DEFAULT_KEY_SIGNATURE_SIZE ECRYPTFS_SIG_SIZE
+#define CRYPTOHOME_DEFAULT_KEY_SALT_SIZE ECRYPTFS_SALT_SIZE
+#define CRYPTOHOME_AES_KEY_BYTES ECRYPTFS_AES_KEY_BYTES
+// The default salt length for the user salt
+#define CRYPTOHOME_DEFAULT_SALT_LENGTH 16
+// Macros for min and max
+#define CRYPTOHOME_MIN(X, Y) (((X) < (Y)) ? (X) : (Y))

[mschilder, 2010/05/27 04:20:18]

These are scary of course, double eval of arguments;
CRYPTOHOME_MIN(x++, y--) type stuff.

gcc-ism like a >? b or typeof can help?

+#define CRYPTOHOME_MAX(X, Y) (((X) > (Y)) ? (X) : (Y))
+
+struct VaultKeysetHeader {
+  char signature[2];
+  unsigned char major_version;
+  unsigned char minor_version;
+} __attribute__((__packed__));
+typedef struct VaultKeysetHeader VaultKeysetHeader;
+
+struct VaultKeysetKeys {
+  unsigned char fek[CRYPTOHOME_DEFAULT_KEY_SIZE];
+  unsigned char fek_sig[CRYPTOHOME_DEFAULT_KEY_SIGNATURE_SIZE];
+  unsigned char fek_salt[CRYPTOHOME_DEFAULT_KEY_SALT_SIZE];
+  unsigned char fnek[CRYPTOHOME_DEFAULT_KEY_SIZE];
+  unsigned char fnek_sig[CRYPTOHOME_DEFAULT_KEY_SIGNATURE_SIZE];
+  unsigned char fnek_salt[CRYPTOHOME_DEFAULT_KEY_SALT_SIZE];
+} __attribute__((__packed__));
+typedef struct VaultKeysetKeys VaultKeysetKeys;
+
+}  // cryptohome
+
+#endif  // CRYPTOHOME_COMMON_H_