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/ec_private_key.h"
6
7 #include <openssl/ec.h>
8 #include <openssl/evp.h>
9 #include <openssl/pkcs12.h>
10 #include <openssl/x509.h>
11
12 #include "base/logging.h"
13 #include "base/memory/scoped_ptr.h"
14 #include "crypto/openssl_util.h"
15
16 namespace crypto {
17
18 namespace {
19
20 // Function pointer definition, for injecting the required key export function
21 // into ExportKeyWithBio, below. |bio| is a temporary memory BIO object, and
22 // |key| is a handle to the input key object. Return 1 on success, 0 otherwise.
23 // NOTE: Used with OpenSSL functions, which do not comply with the Chromium
24 // style guide, hence the unusual parameter placement / types.
25 typedef int (*ExportBioFunction)(BIO* bio, const void* key);
26
27 // Helper to export |key| into |output| via the specified ExportBioFunction.
ExportKeyWithBio(const void * key,ExportBioFunction export_fn,std::vector<uint8> * output)28 bool ExportKeyWithBio(const void* key,
29 ExportBioFunction export_fn,
30 std::vector<uint8>* output) {
31 if (!key)
32 return false;
33
34 ScopedOpenSSL<BIO, BIO_free_all> bio(BIO_new(BIO_s_mem()));
35 if (!bio.get())
36 return false;
37
38 if (!export_fn(bio.get(), key))
39 return false;
40
41 char* data = NULL;
42 long len = BIO_get_mem_data(bio.get(), &data);
43 if (!data || len < 0)
44 return false;
45
46 output->assign(data, data + len);
47 return true;
48 }
49
50 // Function pointer definition, for injecting the required key export function
51 // into ExportKey below. |key| is a pointer to the input key object,
52 // and |data| is either NULL, or the address of an 'unsigned char*' pointer
53 // that points to the start of the output buffer. The function must return
54 // the number of bytes required to export the data, or -1 in case of error.
55 typedef int (*ExportDataFunction)(const void* key, unsigned char** data);
56
57 // Helper to export |key| into |output| via the specified export function.
ExportKey(const void * key,ExportDataFunction export_fn,std::vector<uint8> * output)58 bool ExportKey(const void* key,
59 ExportDataFunction export_fn,
60 std::vector<uint8>* output) {
61 if (!key)
62 return false;
63
64 int data_len = export_fn(key, NULL);
65 if (data_len < 0)
66 return false;
67
68 output->resize(static_cast<size_t>(data_len));
69 unsigned char* data = &(*output)[0];
70 if (export_fn(key, &data) < 0)
71 return false;
72
73 return true;
74 }
75
76 } // namespace
77
~ECPrivateKey()78 ECPrivateKey::~ECPrivateKey() {
79 if (key_)
80 EVP_PKEY_free(key_);
81 }
82
83 // static
IsSupported()84 bool ECPrivateKey::IsSupported() { return true; }
85
86 // static
Create()87 ECPrivateKey* ECPrivateKey::Create() {
88 OpenSSLErrStackTracer err_tracer(FROM_HERE);
89
90 ScopedOpenSSL<EC_KEY, EC_KEY_free> ec_key(
91 EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
92 if (!ec_key.get() || !EC_KEY_generate_key(ec_key.get()))
93 return NULL;
94
95 scoped_ptr<ECPrivateKey> result(new ECPrivateKey());
96 result->key_ = EVP_PKEY_new();
97 if (!result->key_ || !EVP_PKEY_set1_EC_KEY(result->key_, ec_key.get()))
98 return NULL;
99
100 return result.release();
101 }
102
103 // static
CreateFromEncryptedPrivateKeyInfo(const std::string & password,const std::vector<uint8> & encrypted_private_key_info,const std::vector<uint8> & subject_public_key_info)104 ECPrivateKey* ECPrivateKey::CreateFromEncryptedPrivateKeyInfo(
105 const std::string& password,
106 const std::vector<uint8>& encrypted_private_key_info,
107 const std::vector<uint8>& subject_public_key_info) {
108 // NOTE: The |subject_public_key_info| can be ignored here, it is only
109 // useful for the NSS implementation (which uses the public key's SHA1
110 // as a lookup key when storing the private one in its store).
111 if (encrypted_private_key_info.empty())
112 return NULL;
113
114 OpenSSLErrStackTracer err_tracer(FROM_HERE);
115 // Write the encrypted private key into a memory BIO.
116 char* private_key_data = reinterpret_cast<char*>(
117 const_cast<uint8*>(&encrypted_private_key_info[0]));
118 int private_key_data_len =
119 static_cast<int>(encrypted_private_key_info.size());
120 ScopedOpenSSL<BIO, BIO_free_all> bio(
121 BIO_new_mem_buf(private_key_data, private_key_data_len));
122 if (!bio.get())
123 return NULL;
124
125 // Convert it, then decrypt it into a PKCS#8 object.
126 ScopedOpenSSL<X509_SIG, X509_SIG_free> p8_encrypted(
127 d2i_PKCS8_bio(bio.get(), NULL));
128 if (!p8_encrypted.get())
129 return NULL;
130
131 ScopedOpenSSL<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_free> p8_decrypted(
132 PKCS8_decrypt(p8_encrypted.get(),
133 password.c_str(),
134 static_cast<int>(password.size())));
135 if (!p8_decrypted.get())
136 return NULL;
137
138 // Create a new EVP_PKEY for it.
139 scoped_ptr<ECPrivateKey> result(new ECPrivateKey);
140 result->key_ = EVP_PKCS82PKEY(p8_decrypted.get());
141 if (!result->key_)
142 return NULL;
143
144 return result.release();
145 }
146
ExportEncryptedPrivateKey(const std::string & password,int iterations,std::vector<uint8> * output)147 bool ECPrivateKey::ExportEncryptedPrivateKey(
148 const std::string& password,
149 int iterations,
150 std::vector<uint8>* output) {
151 OpenSSLErrStackTracer err_tracer(FROM_HERE);
152 // Convert into a PKCS#8 object.
153 ScopedOpenSSL<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_free> pkcs8(
154 EVP_PKEY2PKCS8(key_));
155 if (!pkcs8.get())
156 return false;
157
158 // Encrypt the object.
159 // NOTE: NSS uses SEC_OID_PKCS12_V2_PBE_WITH_SHA1_AND_3KEY_TRIPLE_DES_CBC
160 // so use NID_pbe_WithSHA1And3_Key_TripleDES_CBC which should be the OpenSSL
161 // equivalent.
162 ScopedOpenSSL<X509_SIG, X509_SIG_free> encrypted(
163 PKCS8_encrypt(NID_pbe_WithSHA1And3_Key_TripleDES_CBC,
164 NULL,
165 password.c_str(),
166 static_cast<int>(password.size()),
167 NULL,
168 0,
169 iterations,
170 pkcs8.get()));
171 if (!encrypted.get())
172 return false;
173
174 // Write it into |*output|
175 return ExportKeyWithBio(encrypted.get(),
176 reinterpret_cast<ExportBioFunction>(i2d_PKCS8_bio),
177 output);
178 }
179
ExportPublicKey(std::vector<uint8> * output)180 bool ECPrivateKey::ExportPublicKey(std::vector<uint8>* output) {
181 OpenSSLErrStackTracer err_tracer(FROM_HERE);
182 return ExportKeyWithBio(
183 key_, reinterpret_cast<ExportBioFunction>(i2d_PUBKEY_bio), output);
184 }
185
ExportValue(std::vector<uint8> * output)186 bool ECPrivateKey::ExportValue(std::vector<uint8>* output) {
187 OpenSSLErrStackTracer err_tracer(FROM_HERE);
188 ScopedOpenSSL<EC_KEY, EC_KEY_free> ec_key(EVP_PKEY_get1_EC_KEY(key_));
189 return ExportKey(ec_key.get(),
190 reinterpret_cast<ExportDataFunction>(i2d_ECPrivateKey),
191 output);
192 }
193
ExportECParams(std::vector<uint8> * output)194 bool ECPrivateKey::ExportECParams(std::vector<uint8>* output) {
195 OpenSSLErrStackTracer err_tracer(FROM_HERE);
196 ScopedOpenSSL<EC_KEY, EC_KEY_free> ec_key(EVP_PKEY_get1_EC_KEY(key_));
197 return ExportKey(ec_key.get(),
198 reinterpret_cast<ExportDataFunction>(i2d_ECParameters),
199 output);
200 }
201
ECPrivateKey()202 ECPrivateKey::ECPrivateKey() : key_(NULL) {}
203
204 } // namespace crypto
205