1 // Copyright 2012 The Chromium Authors
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 <stddef.h>
8 #include <stdint.h>
9
10 #include <utility>
11
12 #include "base/check_op.h"
13 #include "crypto/openssl_util.h"
14 #include "third_party/boringssl/src/include/openssl/bytestring.h"
15 #include "third_party/boringssl/src/include/openssl/ec.h"
16 #include "third_party/boringssl/src/include/openssl/ec_key.h"
17 #include "third_party/boringssl/src/include/openssl/evp.h"
18 #include "third_party/boringssl/src/include/openssl/mem.h"
19 #include "third_party/boringssl/src/include/openssl/pkcs8.h"
20
21 namespace crypto {
22
23 ECPrivateKey::~ECPrivateKey() = default;
24
25 // static
Create()26 std::unique_ptr<ECPrivateKey> ECPrivateKey::Create() {
27 OpenSSLErrStackTracer err_tracer(FROM_HERE);
28
29 bssl::UniquePtr<EC_KEY> ec_key(
30 EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
31 if (!ec_key || !EC_KEY_generate_key(ec_key.get()))
32 return nullptr;
33
34 std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
35 result->key_.reset(EVP_PKEY_new());
36 if (!result->key_ || !EVP_PKEY_set1_EC_KEY(result->key_.get(), ec_key.get()))
37 return nullptr;
38
39 CHECK_EQ(EVP_PKEY_EC, EVP_PKEY_id(result->key_.get()));
40 return result;
41 }
42
43 // static
CreateFromPrivateKeyInfo(base::span<const uint8_t> input)44 std::unique_ptr<ECPrivateKey> ECPrivateKey::CreateFromPrivateKeyInfo(
45 base::span<const uint8_t> input) {
46 OpenSSLErrStackTracer err_tracer(FROM_HERE);
47
48 CBS cbs;
49 CBS_init(&cbs, input.data(), input.size());
50 bssl::UniquePtr<EVP_PKEY> pkey(EVP_parse_private_key(&cbs));
51 if (!pkey || CBS_len(&cbs) != 0 || EVP_PKEY_id(pkey.get()) != EVP_PKEY_EC)
52 return nullptr;
53
54 std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
55 result->key_ = std::move(pkey);
56 return result;
57 }
58
59 // static
CreateFromEncryptedPrivateKeyInfo(base::span<const uint8_t> encrypted_private_key_info)60 std::unique_ptr<ECPrivateKey> ECPrivateKey::CreateFromEncryptedPrivateKeyInfo(
61 base::span<const uint8_t> encrypted_private_key_info) {
62 OpenSSLErrStackTracer err_tracer(FROM_HERE);
63
64 CBS cbs;
65 CBS_init(&cbs, encrypted_private_key_info.data(),
66 encrypted_private_key_info.size());
67 bssl::UniquePtr<EVP_PKEY> pkey(
68 PKCS8_parse_encrypted_private_key(&cbs, "", 0));
69
70 // Hack for reading keys generated by an older version of the OpenSSL code.
71 // Some implementations encode the empty password as "\0\0" (passwords are
72 // normally encoded in big-endian UCS-2 with a NUL terminator) and some
73 // encode as the empty string. PKCS8_parse_encrypted_private_key
74 // distinguishes the two by whether the password is nullptr.
75 if (!pkey) {
76 CBS_init(&cbs, encrypted_private_key_info.data(),
77 encrypted_private_key_info.size());
78 pkey.reset(PKCS8_parse_encrypted_private_key(&cbs, nullptr, 0));
79 }
80
81 if (!pkey || CBS_len(&cbs) != 0 || EVP_PKEY_id(pkey.get()) != EVP_PKEY_EC)
82 return nullptr;
83
84 std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
85 result->key_ = std::move(pkey);
86 return result;
87 }
88
Copy() const89 std::unique_ptr<ECPrivateKey> ECPrivateKey::Copy() const {
90 std::unique_ptr<ECPrivateKey> copy(new ECPrivateKey());
91 copy->key_ = bssl::UpRef(key_);
92 return copy;
93 }
94
ExportPrivateKey(std::vector<uint8_t> * output) const95 bool ECPrivateKey::ExportPrivateKey(std::vector<uint8_t>* output) const {
96 OpenSSLErrStackTracer err_tracer(FROM_HERE);
97 uint8_t* der;
98 size_t der_len;
99 bssl::ScopedCBB cbb;
100 if (!CBB_init(cbb.get(), 0) ||
101 !EVP_marshal_private_key(cbb.get(), key_.get()) ||
102 !CBB_finish(cbb.get(), &der, &der_len)) {
103 return false;
104 }
105 output->assign(der, der + der_len);
106 OPENSSL_free(der);
107 return true;
108 }
109
ExportPublicKey(std::vector<uint8_t> * output) const110 bool ECPrivateKey::ExportPublicKey(std::vector<uint8_t>* output) const {
111 OpenSSLErrStackTracer err_tracer(FROM_HERE);
112 uint8_t* der;
113 size_t der_len;
114 bssl::ScopedCBB cbb;
115 if (!CBB_init(cbb.get(), 0) ||
116 !EVP_marshal_public_key(cbb.get(), key_.get()) ||
117 !CBB_finish(cbb.get(), &der, &der_len)) {
118 return false;
119 }
120 output->assign(der, der + der_len);
121 OPENSSL_free(der);
122 return true;
123 }
124
ExportRawPublicKey(std::string * output) const125 bool ECPrivateKey::ExportRawPublicKey(std::string* output) const {
126 OpenSSLErrStackTracer err_tracer(FROM_HERE);
127
128 std::array<uint8_t, 65> buf;
129 EC_KEY* ec_key = EVP_PKEY_get0_EC_KEY(key_.get());
130 if (!EC_POINT_point2oct(EC_KEY_get0_group(ec_key),
131 EC_KEY_get0_public_key(ec_key),
132 POINT_CONVERSION_UNCOMPRESSED, buf.data(), buf.size(),
133 /*ctx=*/nullptr)) {
134 return false;
135 }
136
137 output->assign(buf.begin(), buf.end());
138 return true;
139 }
140
141 ECPrivateKey::ECPrivateKey() = default;
142
143 } // namespace crypto
144