1 // Copyright (c) 2012 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_creator.h"
6
7 #include <openssl/evp.h>
8 #include <openssl/rsa.h>
9 #include <stddef.h>
10 #include <stdint.h>
11
12 #include "base/logging.h"
13 #include "base/memory/scoped_ptr.h"
14 #include "crypto/openssl_util.h"
15 #include "crypto/rsa_private_key.h"
16 #include "crypto/scoped_openssl_types.h"
17
18 namespace crypto {
19
20 namespace {
21
ToOpenSSLDigest(SignatureCreator::HashAlgorithm hash_alg)22 const EVP_MD* ToOpenSSLDigest(SignatureCreator::HashAlgorithm hash_alg) {
23 switch (hash_alg) {
24 case SignatureCreator::SHA1:
25 return EVP_sha1();
26 case SignatureCreator::SHA256:
27 return EVP_sha256();
28 }
29 return NULL;
30 }
31
ToOpenSSLDigestType(SignatureCreator::HashAlgorithm hash_alg)32 int ToOpenSSLDigestType(SignatureCreator::HashAlgorithm hash_alg) {
33 switch (hash_alg) {
34 case SignatureCreator::SHA1:
35 return NID_sha1;
36 case SignatureCreator::SHA256:
37 return NID_sha256;
38 }
39 return NID_undef;
40 }
41
42 } // namespace
43
44 // static
Create(RSAPrivateKey * key,HashAlgorithm hash_alg)45 SignatureCreator* SignatureCreator::Create(RSAPrivateKey* key,
46 HashAlgorithm hash_alg) {
47 OpenSSLErrStackTracer err_tracer(FROM_HERE);
48 scoped_ptr<SignatureCreator> result(new SignatureCreator);
49 const EVP_MD* const digest = ToOpenSSLDigest(hash_alg);
50 DCHECK(digest);
51 if (!digest) {
52 return NULL;
53 }
54 if (!EVP_DigestSignInit(result->sign_context_, NULL, digest, NULL,
55 key->key())) {
56 return NULL;
57 }
58 return result.release();
59 }
60
61 // static
Sign(RSAPrivateKey * key,HashAlgorithm hash_alg,const uint8_t * data,int data_len,std::vector<uint8_t> * signature)62 bool SignatureCreator::Sign(RSAPrivateKey* key,
63 HashAlgorithm hash_alg,
64 const uint8_t* data,
65 int data_len,
66 std::vector<uint8_t>* signature) {
67 ScopedRSA rsa_key(EVP_PKEY_get1_RSA(key->key()));
68 if (!rsa_key)
69 return false;
70 signature->resize(RSA_size(rsa_key.get()));
71
72 unsigned int len = 0;
73 if (!RSA_sign(ToOpenSSLDigestType(hash_alg), data, data_len,
74 signature->data(), &len, rsa_key.get())) {
75 signature->clear();
76 return false;
77 }
78 signature->resize(len);
79 return true;
80 }
81
SignatureCreator()82 SignatureCreator::SignatureCreator()
83 : sign_context_(EVP_MD_CTX_create()) {
84 }
85
~SignatureCreator()86 SignatureCreator::~SignatureCreator() {
87 EVP_MD_CTX_destroy(sign_context_);
88 }
89
Update(const uint8_t * data_part,int data_part_len)90 bool SignatureCreator::Update(const uint8_t* data_part, int data_part_len) {
91 OpenSSLErrStackTracer err_tracer(FROM_HERE);
92 return !!EVP_DigestSignUpdate(sign_context_, data_part, data_part_len);
93 }
94
Final(std::vector<uint8_t> * signature)95 bool SignatureCreator::Final(std::vector<uint8_t>* signature) {
96 OpenSSLErrStackTracer err_tracer(FROM_HERE);
97
98 // Determine the maximum length of the signature.
99 size_t len = 0;
100 if (!EVP_DigestSignFinal(sign_context_, NULL, &len)) {
101 signature->clear();
102 return false;
103 }
104 signature->resize(len);
105
106 // Sign it.
107 if (!EVP_DigestSignFinal(sign_context_, signature->data(), &len)) {
108 signature->clear();
109 return false;
110 }
111 signature->resize(len);
112 return true;
113 }
114
115 } // namespace crypto
116