Move CUP to new component client_update_protocol

components/client_update_protocol/ecdsa.h

 // Copyright 2016 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 COMPONENTS_UPDATE_CLIENT_CLIENT_UPDATE_PROTOCOL_ECDSA_H_
-#define COMPONENTS_UPDATE_CLIENT_CLIENT_UPDATE_PROTOCOL_ECDSA_H_
+#ifndef COMPONENTS_CLIENT_UPDATE_PROTOCOL_ECDSA_H_
+#define COMPONENTS_CLIENT_UPDATE_PROTOCOL_ECDSA_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_piece.h"
 
-namespace update_client {
+namespace client_update_protocol {
 
 // Client Update Protocol v2, or CUP-ECDSA, is used by Google Update (Omaha)
-// servers to ensure freshness and authenticity of update checks over HTTP,
-// without the overhead of HTTPS -- namely, no PKI, no guarantee of privacy,
-// and no request replay protection (since update checks are idempotent).
+// servers to ensure freshness and authenticity of server responses over HTTP,
+// without the overhead of HTTPS -- namely, no PKI, no guarantee of privacy, and
+// no request replay protection.
 //
 // CUP-ECDSA relies on a single signing operation using ECDSA with SHA-256,
 // instead of the original CUP which used HMAC-SHA1 with a random signing key
 // encrypted using RSA.
 //
-// Each ClientUpdateProtocolEcdsa object represents a single update check in
-// flight -- a call to SignRequest() generates internal state that will be used
-// by ValidateResponse().
-class ClientUpdateProtocolEcdsa {
+// Each |Ecdsa| object represents a single network ping in flight -- a call to
+// SignRequest() generates internal state that will be used by
+// ValidateResponse().
+class Ecdsa {
  public:
-  ~ClientUpdateProtocolEcdsa();
+  ~Ecdsa();
 
   // Initializes this instance of CUP-ECDSA with a versioned public key.
   // |key_version| must be non-negative. |public_key| is expected to be a
   // DER-encoded ASN.1 SubjectPublicKeyInfo containing an ECDSA public key.
   // Returns a NULL pointer on failure.
-  static scoped_ptr<ClientUpdateProtocolEcdsa> Create(
-      int key_version,
-      const base::StringPiece& public_key);
+  static scoped_ptr<Ecdsa> Create(int key_version,
+                                  const base::StringPiece& public_key);
 
-  // Generates freshness/authentication data for an outgoing update check.
-  // |request_body| contains the body of the update check request in UTF-8.
-  // On return, |query_params| contains a set of query parameters (in UTF-8)
-  // to be appended to the URL.
+  // Generates freshness/authentication data for an outgoing ping.
+  // |request_body| contains the body of the ping in UTF-8.  On return,
+  // |query_params| contains a set of query parameters (in UTF-8) to be appended
+  // to the URL.
   //
   // This method will store internal state in this instance used by calls to
-  // ValidateResponse(); if you need to have multiple update checks in flight,
+  // ValidateResponse(); if you need to have multiple pings in flight,
   // initialize a separate CUP-ECDSA instance for each one.
   void SignRequest(const base::StringPiece& request_body,
                    std::string* query_params);
 
-  // Validates a response given to a update check request previously signed
-  // with SignRequest(). |response_body| contains the body of the response in
+  // Validates a response given to a ping previously signed with
+  // SignRequest(). |response_body| contains the body of the response in
   // UTF-8. |server_proof| contains the ECDSA signature and observed request
-  // hash, which is passed in the ETag HTTP header. Returns true if the
-  // response is valid and the observed request hash matches the sent hash.
-  // This method uses internal state that is set by a prior SignRequest() call.
+  // hash, which is passed in the ETag HTTP header. Returns true if the response
+  // is valid and the observed request hash matches the sent hash.  This method
+  // uses internal state that is set by a prior SignRequest() call.
   bool ValidateResponse(const base::StringPiece& response_body,
                         const base::StringPiece& server_etag);
 
  private:
   friend class CupEcdsaTest;
 
-  ClientUpdateProtocolEcdsa(int key_version,
-                            const base::StringPiece& public_key);
+  Ecdsa(int key_version, const base::StringPiece& public_key);
 
   // The server keeps multiple signing keys; a version must be sent so that
   // the correct signing key is used to sign the assembled message.
   const int pub_key_version_;
 
   // The ECDSA public key to use for verifying response signatures.
   const std::vector<uint8_t> public_key_;
 
   // The SHA-256 hash of the XML request.  This is modified on each call to
   // SignRequest(), and checked by ValidateResponse().
   std::vector<uint8_t> request_hash_;
 
   // The query string containing key version and nonce in UTF-8 form.  This is
   // modified on each call to SignRequest(), and checked by ValidateResponse().
   std::string request_query_cup2key_;
 
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ClientUpdateProtocolEcdsa);
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Ecdsa);
 };
 
-}  // namespace update_client
+}  // namespace client_update_protocol
 
-#endif  // COMPONENTS_UPDATE_CLIENT_CLIENT_UPDATE_PROTOCOL_ECDSA_H_
+#endif  // COMPONENTS_CLIENT_UPDATE_PROTOCOL_ECDSA_H_