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      1 // Copyright (c) 2011 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 "crypto/signature_verifier.h"
      6 
      7 #include <stdlib.h>
      8 
      9 #include "base/logging.h"
     10 #include "crypto/cssm_init.h"
     11 
     12 namespace crypto {
     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 crypto
    105 
    106