Remove CUP from google_apis

google_apis/cup/client_update_protocol.cc

Index: google_apis/cup/client_update_protocol.cc
diff --git a/google_apis/cup/client_update_protocol.cc b/google_apis/cup/client_update_protocol.cc
deleted file mode 100644
index afde3ab46b5b0d3cb693d64d2358aea904da2370..0000000000000000000000000000000000000000
--- a/google_apis/cup/client_update_protocol.cc
+++ /dev/null
@@ -1,303 +0,0 @@
-// Copyright 2013 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 "google_apis/cup/client_update_protocol.h"
-
-#include "base/base64.h"
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/sha1.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "crypto/hmac.h"
-#include "crypto/random.h"
-
-namespace {
-
-base::StringPiece ByteVectorToSP(const std::vector<uint8>& vec) {
-  if (vec.empty())
-    return base::StringPiece();
-
-  return base::StringPiece(reinterpret_cast<const char*>(&vec[0]), vec.size());
-}
-
-// This class needs to implement the same hashing and signing functions as the
-// Google Update server; for now, this is SHA-1 and HMAC-SHA1, but this may
-// change to SHA-256 in the near future.  For this reason, all primitives are
-// wrapped.  The name "SymSign" is used to mirror the CUP specification.
-size_t HashDigestSize() {
-  return base::kSHA1Length;
-}
-
-std::vector<uint8> Hash(const std::vector<uint8>& data) {
-  std::vector<uint8> result(HashDigestSize());
-  base::SHA1HashBytes(data.empty() ? NULL : &data[0],
-                      data.size(),
-                      &result[0]);
-  return result;
-}
-
-std::vector<uint8> Hash(const base::StringPiece& sdata) {
-  std::vector<uint8> result(HashDigestSize());
-  base::SHA1HashBytes(sdata.empty() ?
-                          NULL :
-                          reinterpret_cast<const unsigned char*>(sdata.data()),
-                      sdata.length(),
-                      &result[0]);
-  return result;
-}
-
-std::vector<uint8> SymConcat(uint8 id,
-                             const std::vector<uint8>* h1,
-                             const std::vector<uint8>* h2,
-                             const std::vector<uint8>* h3) {
-  std::vector<uint8> result;
-  result.push_back(id);
-  const std::vector<uint8>* args[] = { h1, h2, h3 };
-  for (size_t i = 0; i != arraysize(args); ++i) {
-    if (args[i]) {
-      DCHECK_EQ(args[i]->size(), HashDigestSize());
-      result.insert(result.end(), args[i]->begin(), args[i]->end());
-    }
-  }
-
-  return result;
-}
-
-std::vector<uint8> SymSign(const std::vector<uint8>& key,
-                           const std::vector<uint8>& hashes) {
-  DCHECK(!key.empty());
-  DCHECK(!hashes.empty());
-
-  crypto::HMAC hmac(crypto::HMAC::SHA1);
-  if (!hmac.Init(&key[0], key.size()))
-    return std::vector<uint8>();
-
-  std::vector<uint8> result(hmac.DigestLength());
-  if (!hmac.Sign(ByteVectorToSP(hashes), &result[0], result.size()))
-    return std::vector<uint8>();
-
-  return result;
-}
-
-bool SymSignVerify(const std::vector<uint8>& key,
-                   const std::vector<uint8>& hashes,
-                   const std::vector<uint8>& server_proof) {
-  DCHECK(!key.empty());
-  DCHECK(!hashes.empty());
-  DCHECK(!server_proof.empty());
-
-  crypto::HMAC hmac(crypto::HMAC::SHA1);
-  if (!hmac.Init(&key[0], key.size()))
-    return false;
-
-  return hmac.Verify(ByteVectorToSP(hashes), ByteVectorToSP(server_proof));
-}
-
-// RsaPad() is implemented as described in the CUP spec.  It is NOT a general
-// purpose padding algorithm.
-std::vector<uint8> RsaPad(size_t rsa_key_size,
-                          const std::vector<uint8>& entropy) {
-  DCHECK_GE(rsa_key_size, HashDigestSize());
-
-  // The result gets padded with zeros if the result size is greater than
-  // the size of the buffer provided by the caller.
-  std::vector<uint8> result(entropy);
-  result.resize(rsa_key_size - HashDigestSize());
-
-  // For use with RSA, the input needs to be smaller than the RSA modulus,
-  // which has always the msb set.
-  result[0] &= 127;  // Reset msb
-  result[0] |= 64;   // Set second highest bit.
-
-  std::vector<uint8> digest = Hash(result);
-  result.insert(result.end(), digest.begin(), digest.end());
-  DCHECK_EQ(result.size(), rsa_key_size);
-  return result;
-}
-
-// CUP passes the versioned secret in the query portion of the URL for the
-// update check service -- and that means that a URL-safe variant of Base64 is
-// needed.  Call the standard Base64 encoder/decoder and then apply fixups.
-std::string UrlSafeB64Encode(const std::vector<uint8>& data) {
-  std::string result;
-  base::Base64Encode(ByteVectorToSP(data), &result);
-
-  // Do an tr|+/|-_| on the output, and strip any '=' padding.
-  for (std::string::iterator it = result.begin(); it != result.end(); ++it) {
-    switch (*it) {
-      case '+':
-        *it = '-';
-        break;
-      case '/':
-        *it = '_';
-        break;
-      default:
-        break;
-    }
-  }
-  base::TrimString(result, "=", &result);
-
-  return result;
-}
-
-std::vector<uint8> UrlSafeB64Decode(const base::StringPiece& input) {
-  std::string unsafe(input.begin(), input.end());
-  for (std::string::iterator it = unsafe.begin(); it != unsafe.end(); ++it) {
-    switch (*it) {
-      case '-':
-        *it = '+';
-        break;
-      case '_':
-        *it = '/';
-        break;
-      default:
-        break;
-    }
-  }
-  if (unsafe.length() % 4)
-    unsafe.append(4 - (unsafe.length() % 4), '=');
-
-  std::string decoded;
-  if (!base::Base64Decode(unsafe, &decoded))
-    return std::vector<uint8>();
-
-  return std::vector<uint8>(decoded.begin(), decoded.end());
-}
-
-}  // end namespace
-
-ClientUpdateProtocol::ClientUpdateProtocol(int key_version)
-    : pub_key_version_(key_version) {
-}
-
-scoped_ptr<ClientUpdateProtocol> ClientUpdateProtocol::Create(
-    int key_version,
-    const base::StringPiece& public_key) {
-  DCHECK_GT(key_version, 0);
-  DCHECK(!public_key.empty());
-
-  scoped_ptr<ClientUpdateProtocol> result(
-      new ClientUpdateProtocol(key_version));
-  if (!result)
-    return scoped_ptr<ClientUpdateProtocol>();
-
-  if (!result->LoadPublicKey(public_key))
-    return scoped_ptr<ClientUpdateProtocol>();
-
-  if (!result->BuildRandomSharedKey())
-    return scoped_ptr<ClientUpdateProtocol>();
-
-  return result.Pass();
-}
-
-std::string ClientUpdateProtocol::GetVersionedSecret() const {
-  return base::StringPrintf("%d:%s",
-                            pub_key_version_,
-                            UrlSafeB64Encode(encrypted_key_source_).c_str());
-}
-
-bool ClientUpdateProtocol::SignRequest(const base::StringPiece& url,
-                                       const base::StringPiece& request_body,
-                                       std::string* client_proof) {
-  DCHECK(!encrypted_key_source_.empty());
-  DCHECK(!url.empty());
-  DCHECK(!request_body.empty());
-  DCHECK(client_proof);
-
-  // Compute the challenge hash:
-  //   hw = HASH(HASH(v|w)|HASH(request_url)|HASH(body)).
-  // Keep the challenge hash for later to validate the server's response.
-  std::vector<uint8> internal_hashes;
-
-  std::vector<uint8> h;
-  h = Hash(GetVersionedSecret());
-  internal_hashes.insert(internal_hashes.end(), h.begin(), h.end());
-  h = Hash(url);
-  internal_hashes.insert(internal_hashes.end(), h.begin(), h.end());
-  h = Hash(request_body);
-  internal_hashes.insert(internal_hashes.end(), h.begin(), h.end());
-  DCHECK_EQ(internal_hashes.size(), 3 * HashDigestSize());
-
-  client_challenge_hash_ = Hash(internal_hashes);
-
-  // Sign the challenge hash (hw) using the shared key (sk) to produce the
-  // client proof (cp).
-  std::vector<uint8> raw_client_proof =
-      SymSign(shared_key_, SymConcat(3, &client_challenge_hash_, NULL, NULL));
-  if (raw_client_proof.empty()) {
-    client_challenge_hash_.clear();
-    return false;
-  }
-
-  *client_proof = UrlSafeB64Encode(raw_client_proof);
-  return true;
-}
-
-bool ClientUpdateProtocol::ValidateResponse(
-    const base::StringPiece& response_body,
-    const base::StringPiece& server_cookie,
-    const base::StringPiece& server_proof) {
-  DCHECK(!client_challenge_hash_.empty());
-
-  if (response_body.empty() || server_cookie.empty() || server_proof.empty())
-    return false;
-
-  // Decode the server proof from URL-safe Base64 to a binary HMAC for the
-  // response.
-  std::vector<uint8> sp_decoded = UrlSafeB64Decode(server_proof);
-  if (sp_decoded.empty())
-    return false;
-
-  // If the request was received by the server, the server will use its
-  // private key to decrypt |w_|, yielding the original contents of |r_|.
-  // The server can then recreate |sk_|, compute |hw_|, and SymSign(3|hw)
-  // to ensure that the cp matches the contents.  It will then use |sk_|
-  // to sign its response, producing the server proof |sp|.
-  std::vector<uint8> hm = Hash(response_body);
-  std::vector<uint8> hc = Hash(server_cookie);
-  return SymSignVerify(shared_key_,
-                       SymConcat(1, &client_challenge_hash_, &hm, &hc),
-                       sp_decoded);
-}
-
-bool ClientUpdateProtocol::BuildRandomSharedKey() {
-  DCHECK_GE(PublicKeyLength(), HashDigestSize());
-
-  // Start by generating some random bytes that are suitable to be encrypted;
-  // this will be the source of the shared HMAC key that client and server use.
-  // (CUP specification calls this "r".)
-  std::vector<uint8> key_source;
-  std::vector<uint8> entropy(PublicKeyLength() - HashDigestSize());
-  crypto::RandBytes(&entropy[0], entropy.size());
-  key_source = RsaPad(PublicKeyLength(), entropy);
-
-  return DeriveSharedKey(key_source);
-}
-
-bool ClientUpdateProtocol::SetSharedKeyForTesting(
-  const base::StringPiece& key_source) {
-  DCHECK_EQ(key_source.length(), PublicKeyLength());
-
-  return DeriveSharedKey(std::vector<uint8>(key_source.begin(),
-                                            key_source.end()));
-}
-
-bool ClientUpdateProtocol::DeriveSharedKey(const std::vector<uint8>& source) {
-  DCHECK(!source.empty());
-  DCHECK_GE(source.size(), HashDigestSize());
-  DCHECK_EQ(source.size(), PublicKeyLength());
-
-  // Hash the key source (r) to generate a new shared HMAC key (sk').
-  shared_key_ = Hash(source);
-
-  // Encrypt the key source (r) using the public key (pk[v]) to generate the
-  // encrypted key source (w).
-  if (!EncryptKeySource(source))
-    return false;
-  if (encrypted_key_source_.size() != PublicKeyLength())
-    return false;
-
-  return true;
-}