AU: Support signed payload verification through the delta generator.

payload_signer.h

 // Copyright (c) 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H__
 
 #include <string>
 #include <vector>
 
@@ skipping 21 matching lines @@
   // false otherwise.
   static bool SignPayload(const std::string& unsigned_payload_path,
                           const std::string& private_key_path,
                           std::vector<char>* out_signature_blob);
 
   // Returns the length of out_signature_blob that will result in a call
   // to SignPayload with a given private key. Returns true on success.
   static bool SignatureBlobLength(const std::string& private_key_path,
                                   uint64_t* out_length);
 
-  // Returns false if the payload signature can't be verified. Returns true
-  // otherwise and sets |out_hash| to the signed payload hash.
-  static bool VerifySignature(const std::vector<char>& signature_blob,
-                              const std::string& public_key_path,
-                              std::vector<char>* out_hash_data);
-
-
   // Given an unsigned payload in |payload_path| (with no dummy signature op)
   // and the raw |signature_size| calculates the raw hash that needs to be
   // signed in |out_hash_data|. Returns true on success, false otherwise.
   static bool HashPayloadForSigning(const std::string& payload_path,
                                     int signature_size,
                                     std::vector<char>* out_hash_data);
 
   // Given an unsigned payload in |payload_path| (with no dummy signature op)
   // and the raw |signature| updates the payload to include the signature thus
   // turning it into a signed payload. The new payload is stored in
   // |signed_payload_path|. |payload_path| and |signed_payload_path| can point
   // to the same file. Returns true on success, false otherwise.
   static bool AddSignatureToPayload(const std::string& payload_path,
                                     const std::vector<char>& signature,
                                     const std::string& signed_payload_path);
 
+  // Returns false if the payload signature can't be verified. Returns true
+  // otherwise and sets |out_hash| to the signed payload hash.
+  static bool VerifySignature(const std::vector<char>& signature_blob,
+                              const std::string& public_key_path,
+                              std::vector<char>* out_hash_data);
+
+  // Returns true if the payload in |payload_path| is signed and its hash can be
+  // verified using the public key in |public_key_path|. Returns false
+  // otherwise.
+  static bool VerifySignedPayload(const std::string& payload_path,
+                                  const std::string& public_key_path);
+
  private:
   // This should never be constructed
   DISALLOW_IMPLICIT_CONSTRUCTORS(PayloadSigner);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H__