OLD | NEW |
| (Empty) |
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 "base/logging.h" | |
8 | |
9 #pragma comment(lib, "crypt32.lib") | |
10 | |
11 namespace { | |
12 | |
13 // Wrappers of malloc and free for CRYPT_DECODE_PARA, which requires the | |
14 // WINAPI calling convention. | |
15 void* WINAPI MyCryptAlloc(size_t size) { | |
16 return malloc(size); | |
17 } | |
18 | |
19 void WINAPI MyCryptFree(void* p) { | |
20 free(p); | |
21 } | |
22 | |
23 } // namespace | |
24 | |
25 namespace base { | |
26 | |
27 SignatureVerifier::SignatureVerifier() : hash_object_(0), public_key_(0) { | |
28 if (!CryptAcquireContext(provider_.receive(), NULL, NULL, | |
29 PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) | |
30 provider_.reset(); | |
31 } | |
32 | |
33 SignatureVerifier::~SignatureVerifier() { | |
34 } | |
35 | |
36 bool SignatureVerifier::VerifyInit(const uint8* signature_algorithm, | |
37 int signature_algorithm_len, | |
38 const uint8* signature, | |
39 int signature_len, | |
40 const uint8* public_key_info, | |
41 int public_key_info_len) { | |
42 signature_.reserve(signature_len); | |
43 // CryptoAPI uses big integers in the little-endian byte order, so we need | |
44 // to first swap the order of signature bytes. | |
45 for (int i = signature_len - 1; i >= 0; --i) | |
46 signature_.push_back(signature[i]); | |
47 | |
48 CRYPT_DECODE_PARA decode_para; | |
49 decode_para.cbSize = sizeof(decode_para); | |
50 decode_para.pfnAlloc = MyCryptAlloc; | |
51 decode_para.pfnFree = MyCryptFree; | |
52 CERT_PUBLIC_KEY_INFO* cert_public_key_info = NULL; | |
53 DWORD struct_len = 0; | |
54 BOOL ok; | |
55 ok = CryptDecodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, | |
56 X509_PUBLIC_KEY_INFO, | |
57 public_key_info, | |
58 public_key_info_len, | |
59 CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_NOCOPY_FLAG, | |
60 &decode_para, | |
61 &cert_public_key_info, | |
62 &struct_len); | |
63 if (!ok) | |
64 return false; | |
65 | |
66 ok = CryptImportPublicKeyInfo(provider_, | |
67 X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, | |
68 cert_public_key_info, public_key_.receive()); | |
69 free(cert_public_key_info); | |
70 if (!ok) | |
71 return false; | |
72 | |
73 CRYPT_ALGORITHM_IDENTIFIER* signature_algorithm_id; | |
74 struct_len = 0; | |
75 ok = CryptDecodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, | |
76 X509_ALGORITHM_IDENTIFIER, | |
77 signature_algorithm, | |
78 signature_algorithm_len, | |
79 CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_NOCOPY_FLAG, | |
80 &decode_para, | |
81 &signature_algorithm_id, | |
82 &struct_len); | |
83 DCHECK(ok || GetLastError() == ERROR_FILE_NOT_FOUND); | |
84 ALG_ID hash_alg_id; | |
85 if (ok) { | |
86 hash_alg_id = CALG_MD4; // Initialize to a weak hash algorithm that we | |
87 // don't support. | |
88 if (!strcmp(signature_algorithm_id->pszObjId, szOID_RSA_SHA1RSA)) | |
89 hash_alg_id = CALG_SHA1; | |
90 else if (!strcmp(signature_algorithm_id->pszObjId, szOID_RSA_MD5RSA)) | |
91 hash_alg_id = CALG_MD5; | |
92 free(signature_algorithm_id); | |
93 DCHECK(hash_alg_id != CALG_MD4); | |
94 if (hash_alg_id == CALG_MD4) | |
95 return false; // Unsupported hash algorithm. | |
96 } else if (GetLastError() == ERROR_FILE_NOT_FOUND) { | |
97 // TODO(wtc): X509_ALGORITHM_IDENTIFIER isn't supported on XP SP2. We | |
98 // may be able to encapsulate signature_algorithm in a dummy SignedContent | |
99 // and decode it with X509_CERT into a CERT_SIGNED_CONTENT_INFO. For now, | |
100 // just hardcode the hash algorithm to be SHA-1. | |
101 hash_alg_id = CALG_SHA1; | |
102 } else { | |
103 return false; | |
104 } | |
105 | |
106 ok = CryptCreateHash(provider_, hash_alg_id, 0, 0, hash_object_.receive()); | |
107 if (!ok) | |
108 return false; | |
109 return true; | |
110 } | |
111 | |
112 void SignatureVerifier::VerifyUpdate(const uint8* data_part, | |
113 int data_part_len) { | |
114 BOOL ok = CryptHashData(hash_object_, data_part, data_part_len, 0); | |
115 DCHECK(ok) << "CryptHashData failed: " << GetLastError(); | |
116 } | |
117 | |
118 bool SignatureVerifier::VerifyFinal() { | |
119 BOOL ok = CryptVerifySignature(hash_object_, &signature_[0], | |
120 signature_.size(), public_key_, NULL, 0); | |
121 Reset(); | |
122 if (!ok) | |
123 return false; | |
124 return true; | |
125 } | |
126 | |
127 void SignatureVerifier::Reset() { | |
128 hash_object_.reset(); | |
129 public_key_.reset(); | |
130 signature_.clear(); | |
131 } | |
132 | |
133 } // namespace base | |
134 | |
OLD | NEW |