google_apis/cup/client_update_protocol_nss.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "google_apis/cup/client_update_protocol.h"
   6
   7 #include <keyhi.h>
   8 #include <pk11pub.h>
   9 #include <seccomon.h>
  10
  11 #include "base/logging.h"
  12 #include "crypto/nss_util.h"
  13 #include "crypto/scoped_nss_types.h"
  14
  15 typedef scoped_ptr_malloc<
  16     CERTSubjectPublicKeyInfo,
  17     crypto::NSSDestroyer<CERTSubjectPublicKeyInfo,
  18                          SECKEY_DestroySubjectPublicKeyInfo> >
  19     ScopedCERTSubjectPublicKeyInfo;
  20
  21 ClientUpdateProtocol::~ClientUpdateProtocol() {
  22   if (public_key_)
  23     SECKEY_DestroyPublicKey(public_key_);
  24 }
  25
  26 bool ClientUpdateProtocol::LoadPublicKey(const base::StringPiece& public_key) {
  27   crypto::EnsureNSSInit();
  28
  29   // The binary blob |public_key| is expected to be a DER-encoded ASN.1
  30   // Subject Public Key Info.
  31   SECItem spki_item;
  32   spki_item.type = siBuffer;
  33   spki_item.data =
  34       reinterpret_cast<unsigned char*>(const_cast<char*>(public_key.data()));
  35   spki_item.len = static_cast<unsigned int>(public_key.size());
  36
  37   ScopedCERTSubjectPublicKeyInfo spki(
  38       SECKEY_DecodeDERSubjectPublicKeyInfo(&spki_item));
  39   if (!spki.get())
  40     return false;
  41
  42   public_key_ = SECKEY_ExtractPublicKey(spki.get());
  43   if (!public_key_)
  44     return false;
  45
  46   if (!PublicKeyLength())
  47     return false;
  48
  49   return true;
  50 }
  51
  52 size_t ClientUpdateProtocol::PublicKeyLength() {
  53   if (!public_key_)
  54     return 0;
  55
  56   return SECKEY_PublicKeyStrength(public_key_);
  57 }
  58
  59 bool ClientUpdateProtocol::EncryptKeySource(
  60     const std::vector<uint8>& key_source) {
  61   // WARNING: This call bypasses the usual PKCS #1 padding and does direct RSA
  62   // exponentiation.  This is not secure without taking measures to ensure that
  63   // the contents of r are suitable.  This is done to remain compatible with
  64   // the implementation on the Google Update servers; don't copy-paste this
  65   // code arbitrarily and expect it to work and/or remain secure!
  66   if (!public_key_)
  67     return false;
  68
  69   size_t keysize = SECKEY_PublicKeyStrength(public_key_);
  70   if (key_source.size() != keysize)
  71     return false;
  72
  73   encrypted_key_source_.resize(keysize);
  74   return SECSuccess == PK11_PubEncryptRaw(
  75       public_key_,
  76       &encrypted_key_source_[0],
  77       const_cast<unsigned char*>(&key_source[0]),
  78       key_source.size(),
  79       NULL);
  80 }
  81