base/crypto/signature_verifier_mac.cc

   1 // Copyright (c) 2009 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 "base/crypto/signature_verifier.h"
   6
   7 #include <stdlib.h>
   8
   9 #include "base/crypto/cssm_init.h"
  10 #include "base/logging.h"
  11
  12 namespace base {
  13
  14 SignatureVerifier::SignatureVerifier() : sig_handle_(0) {
  15   EnsureCSSMInit();
  16 }
  17
  18 SignatureVerifier::~SignatureVerifier() {
  19   Reset();
  20 }
  21
  22 bool SignatureVerifier::VerifyInit(const uint8* signature_algorithm,
  23                                    int signature_algorithm_len,
  24                                    const uint8* signature,
  25                                    int signature_len,
  26                                    const uint8* public_key_info,
  27                                    int public_key_info_len) {
  28   signature_.assign(signature, signature + signature_len);
  29   public_key_info_.assign(public_key_info,
  30                           public_key_info + public_key_info_len);
  31
  32   CSSM_ALGORITHMS key_alg = CSSM_ALGID_RSA;  // TODO(wtc): hardcoded.
  33
  34   memset(&public_key_, 0, sizeof(public_key_));
  35   public_key_.KeyData.Data = const_cast<uint8*>(&public_key_info_[0]);
  36   public_key_.KeyData.Length = public_key_info_.size();
  37   public_key_.KeyHeader.HeaderVersion = CSSM_KEYHEADER_VERSION;
  38   public_key_.KeyHeader.BlobType = CSSM_KEYBLOB_RAW;
  39   public_key_.KeyHeader.Format = CSSM_KEYBLOB_RAW_FORMAT_X509;
  40   public_key_.KeyHeader.AlgorithmId = key_alg;
  41   public_key_.KeyHeader.KeyClass = CSSM_KEYCLASS_PUBLIC_KEY;
  42   public_key_.KeyHeader.KeyAttr = CSSM_KEYATTR_EXTRACTABLE;
  43   public_key_.KeyHeader.KeyUsage = CSSM_KEYUSE_VERIFY;
  44   CSSM_KEY_SIZE key_size;
  45   CSSM_RETURN crtn;
  46   crtn = CSSM_QueryKeySizeInBits(GetSharedCSPHandle(), NULL,
  47                                  &public_key_, &key_size);
  48   if (crtn) {
  49     NOTREACHED() << "CSSM_QueryKeySizeInBits failed: " << crtn;
  50     return false;
  51   }
  52   public_key_.KeyHeader.LogicalKeySizeInBits = key_size.LogicalKeySizeInBits;
  53
  54   // TODO(wtc): decode signature_algorithm...
  55   CSSM_ALGORITHMS sig_alg = CSSM_ALGID_SHA1WithRSA;
  56
  57   crtn = CSSM_CSP_CreateSignatureContext(GetSharedCSPHandle(), sig_alg, NULL,
  58                                          &public_key_, &sig_handle_);
  59   if (crtn) {
  60     NOTREACHED();
  61     return false;
  62   }
  63   crtn = CSSM_VerifyDataInit(sig_handle_);
  64   if (crtn) {
  65     NOTREACHED();
  66     return false;
  67   }
  68   return true;
  69 }
  70
  71 void SignatureVerifier::VerifyUpdate(const uint8* data_part,
  72                                      int data_part_len) {
  73   CSSM_DATA data;
  74   data.Data = const_cast<uint8*>(data_part);
  75   data.Length = data_part_len;
  76   CSSM_RETURN crtn = CSSM_VerifyDataUpdate(sig_handle_, &data, 1);
  77   DCHECK(crtn == CSSM_OK);
  78 }
  79
  80 bool SignatureVerifier::VerifyFinal() {
  81   CSSM_DATA sig;
  82   sig.Data = const_cast<uint8*>(&signature_[0]);
  83   sig.Length = signature_.size();
  84   CSSM_RETURN crtn = CSSM_VerifyDataFinal(sig_handle_, &sig);
  85   Reset();
  86
  87   // crtn is CSSMERR_CSP_VERIFY_FAILED if signature verification fails.
  88   return (crtn == CSSM_OK);
  89 }
  90
  91 void SignatureVerifier::Reset() {
  92   CSSM_RETURN crtn;
  93   if (sig_handle_) {
  94     crtn = CSSM_DeleteContext(sig_handle_);
  95     DCHECK(crtn == CSSM_OK);
  96     sig_handle_ = 0;
  97   }
  98   signature_.clear();
  99
 100   // Can't call CSSM_FreeKey on public_key_ because we constructed
 101   // public_key_ manually.
 102 }
 103
 104 }  // namespace base
 105