1 // Copyright 2014 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 "chrome/common/extensions/api/networking_private/networking_private_crypto.h"
6
7 #include <cert.h>
8 #include <cryptohi.h>
9 #include <keyhi.h>
10 #include <keythi.h>
11 #include <pk11pub.h>
12 #include <sechash.h>
13 #include <secport.h>
14
15 #include "base/base64.h"
16 #include "base/memory/scoped_ptr.h"
17 #include "base/strings/string_number_conversions.h"
18 #include "base/strings/string_util.h"
19 #include "base/strings/stringprintf.h"
20 #include "crypto/nss_util.h"
21 #include "crypto/rsa_private_key.h"
22 #include "crypto/scoped_nss_types.h"
23 #include "net/cert/pem_tokenizer.h"
24 #include "net/cert/x509_certificate.h"
25
26 const unsigned char kTrustedCAPublicKeyDER[] = {
27 0x30, 0x82, 0x01, 0x0a, 0x02, 0x82, 0x01, 0x01, 0x00, 0xbc, 0x22, 0x80,
28 0xbd, 0x80, 0xf6, 0x3a, 0x21, 0x00, 0x3b, 0xae, 0x76, 0x5e, 0x35, 0x7f,
29 0x3d, 0xc3, 0x64, 0x5c, 0x55, 0x94, 0x86, 0x34, 0x2f, 0x05, 0x87, 0x28,
30 0xcd, 0xf7, 0x69, 0x8c, 0x17, 0xb3, 0x50, 0xa7, 0xb8, 0x82, 0xfa, 0xdf,
31 0xc7, 0x43, 0x2d, 0xd6, 0x7e, 0xab, 0xa0, 0x6f, 0xb7, 0x13, 0x72, 0x80,
32 0xa4, 0x47, 0x15, 0xc1, 0x20, 0x99, 0x50, 0xcd, 0xec, 0x14, 0x62, 0x09,
33 0x5b, 0xa4, 0x98, 0xcd, 0xd2, 0x41, 0xb6, 0x36, 0x4e, 0xff, 0xe8, 0x2e,
34 0x32, 0x30, 0x4a, 0x81, 0xa8, 0x42, 0xa3, 0x6c, 0x9b, 0x33, 0x6e, 0xca,
35 0xb2, 0xf5, 0x53, 0x66, 0xe0, 0x27, 0x53, 0x86, 0x1a, 0x85, 0x1e, 0xa7,
36 0x39, 0x3f, 0x4a, 0x77, 0x8e, 0xfb, 0x54, 0x66, 0x66, 0xfb, 0x58, 0x54,
37 0xc0, 0x5e, 0x39, 0xc7, 0xf5, 0x50, 0x06, 0x0b, 0xe0, 0x8a, 0xd4, 0xce,
38 0xe1, 0x6a, 0x55, 0x1f, 0x8b, 0x17, 0x00, 0xe6, 0x69, 0xa3, 0x27, 0xe6,
39 0x08, 0x25, 0x69, 0x3c, 0x12, 0x9d, 0x8d, 0x05, 0x2c, 0xd6, 0x2e, 0xa2,
40 0x31, 0xde, 0xb4, 0x52, 0x50, 0xd6, 0x20, 0x49, 0xde, 0x71, 0xa0, 0xf9,
41 0xad, 0x20, 0x40, 0x12, 0xf1, 0xdd, 0x25, 0xeb, 0xd5, 0xe6, 0xb8, 0x36,
42 0xf4, 0xd6, 0x8f, 0x7f, 0xca, 0x43, 0xdc, 0xd7, 0x10, 0x5b, 0xe6, 0x3f,
43 0x51, 0x8a, 0x85, 0xb3, 0xf3, 0xff, 0xf6, 0x03, 0x2d, 0xcb, 0x23, 0x4f,
44 0x9c, 0xad, 0x18, 0xe7, 0x93, 0x05, 0x8c, 0xac, 0x52, 0x9a, 0xf7, 0x4c,
45 0xe9, 0x99, 0x7a, 0xbe, 0x6e, 0x7e, 0x4d, 0x0a, 0xe3, 0xc6, 0x1c, 0xa9,
46 0x93, 0xfa, 0x3a, 0xa5, 0x91, 0x5d, 0x1c, 0xbd, 0x66, 0xeb, 0xcc, 0x60,
47 0xdc, 0x86, 0x74, 0xca, 0xcf, 0xf8, 0x92, 0x1c, 0x98, 0x7d, 0x57, 0xfa,
48 0x61, 0x47, 0x9e, 0xab, 0x80, 0xb7, 0xe4, 0x48, 0x80, 0x2a, 0x92, 0xc5,
49 0x1b, 0x02, 0x03, 0x01, 0x00, 0x01};
50
51 namespace {
52
53 // Parses |pem_data| for a PEM block of |pem_type|.
54 // Returns true if a |pem_type| block is found, storing the decoded result in
55 // |der_output|.
GetDERFromPEM(const std::string & pem_data,const std::string & pem_type,std::vector<uint8> * der_output)56 bool GetDERFromPEM(const std::string& pem_data,
57 const std::string& pem_type,
58 std::vector<uint8>* der_output) {
59 std::vector<std::string> headers;
60 headers.push_back(pem_type);
61 net::PEMTokenizer pem_tok(pem_data, headers);
62 if (!pem_tok.GetNext()) {
63 return false;
64 }
65
66 der_output->assign(pem_tok.data().begin(), pem_tok.data().end());
67 return true;
68 }
69
70 } // namespace
71
NetworkingPrivateCrypto()72 NetworkingPrivateCrypto::NetworkingPrivateCrypto() {}
73
~NetworkingPrivateCrypto()74 NetworkingPrivateCrypto::~NetworkingPrivateCrypto() {}
75
VerifyCredentials(const std::string & certificate,const std::string & signature,const std::string & data,const std::string & connected_mac)76 bool NetworkingPrivateCrypto::VerifyCredentials(
77 const std::string& certificate,
78 const std::string& signature,
79 const std::string& data,
80 const std::string& connected_mac) {
81 crypto::EnsureNSSInit();
82
83 std::vector<uint8> cert_data;
84 if (!GetDERFromPEM(certificate, "CERTIFICATE", &cert_data)) {
85 LOG(ERROR) << "Failed to parse certificate.";
86 return false;
87 }
88 SECItem der_cert;
89 der_cert.type = siDERCertBuffer;
90 der_cert.data = cert_data.data();
91 der_cert.len = cert_data.size();
92
93 // Parse into a certificate structure.
94 typedef scoped_ptr<
95 CERTCertificate,
96 crypto::NSSDestroyer<CERTCertificate, CERT_DestroyCertificate> >
97 ScopedCERTCertificate;
98 ScopedCERTCertificate cert(CERT_NewTempCertificate(
99 CERT_GetDefaultCertDB(), &der_cert, NULL, PR_FALSE, PR_TRUE));
100 if (!cert.get()) {
101 LOG(ERROR) << "Failed to parse certificate.";
102 return false;
103 }
104
105 // Check that the certificate is signed by trusted CA.
106 SECItem trusted_ca_key_der_item;
107 trusted_ca_key_der_item.type = siDERCertBuffer;
108 trusted_ca_key_der_item.data =
109 const_cast<unsigned char*>(kTrustedCAPublicKeyDER),
110 trusted_ca_key_der_item.len = sizeof(kTrustedCAPublicKeyDER);
111 crypto::ScopedSECKEYPublicKey ca_public_key(
112 SECKEY_ImportDERPublicKey(&trusted_ca_key_der_item, CKK_RSA));
113 SECStatus verified = CERT_VerifySignedDataWithPublicKey(
114 &cert->signatureWrap, ca_public_key.get(), NULL);
115 if (verified != SECSuccess) {
116 LOG(ERROR) << "Certificate is not issued by the trusted CA.";
117 return false;
118 }
119
120 // Check that the device listed in the certificate is correct.
121 // Something like evt_e161 001a11ffacdf
122 char* common_name = CERT_GetCommonName(&cert->subject);
123 if (!common_name) {
124 LOG(ERROR) << "Certificate does not have common name.";
125 return false;
126 }
127
128 std::string subject_name(common_name);
129 PORT_Free(common_name);
130 std::string translated_mac;
131 base::RemoveChars(connected_mac, ":", &translated_mac);
132 if (!EndsWith(subject_name, translated_mac, false)) {
133 LOG(ERROR) << "MAC addresses don't match.";
134 return false;
135 }
136
137 // Make sure that the certificate matches the unsigned data presented.
138 // Verify that the |signature| matches |data|.
139 crypto::ScopedSECKEYPublicKey public_key(CERT_ExtractPublicKey(cert.get()));
140 if (!public_key.get()) {
141 LOG(ERROR) << "Unable to extract public key from certificate.";
142 return false;
143 }
144 SECItem signature_item;
145 signature_item.type = siBuffer;
146 signature_item.data =
147 reinterpret_cast<unsigned char*>(const_cast<char*>(signature.c_str()));
148 signature_item.len = static_cast<unsigned int>(signature.size());
149 verified = VFY_VerifyDataDirect(
150 reinterpret_cast<unsigned char*>(const_cast<char*>(data.c_str())),
151 data.size(),
152 public_key.get(),
153 &signature_item,
154 SEC_OID_PKCS1_RSA_ENCRYPTION,
155 SEC_OID_SHA1,
156 NULL,
157 NULL);
158 if (verified != SECSuccess) {
159 LOG(ERROR) << "Signed blobs did not match.";
160 return false;
161 }
162 return true;
163 }
164
EncryptByteString(const std::vector<uint8> & pub_key_der,const std::string & data,std::vector<uint8> * encrypted_output)165 bool NetworkingPrivateCrypto::EncryptByteString(
166 const std::vector<uint8>& pub_key_der,
167 const std::string& data,
168 std::vector<uint8>* encrypted_output) {
169 crypto::EnsureNSSInit();
170
171 SECItem pub_key_der_item;
172 pub_key_der_item.type = siDERCertBuffer;
173 pub_key_der_item.data = const_cast<unsigned char*>(pub_key_der.data());
174 pub_key_der_item.len = pub_key_der.size();
175
176 crypto::ScopedSECKEYPublicKey public_key(
177 SECKEY_ImportDERPublicKey(&pub_key_der_item, CKK_RSA));
178 if (!public_key.get()) {
179 LOG(ERROR) << "Failed to parse public key.";
180 return false;
181 }
182
183 size_t encrypted_length = SECKEY_PublicKeyStrength(public_key.get());
184 // RSAES is defined as operating on messages up to a length of k - 11, where
185 // k is the octet length of the RSA modulus.
186 if (encrypted_length < data.size() + 11) {
187 LOG(ERROR) << "Too much data to encrypt.";
188 return false;
189 }
190
191 scoped_ptr<unsigned char[]> rsa_output(new unsigned char[encrypted_length]);
192 SECStatus encrypted = PK11_PubEncryptPKCS1(
193 public_key.get(),
194 rsa_output.get(),
195 reinterpret_cast<unsigned char*>(const_cast<char*>(data.data())),
196 data.length(),
197 NULL);
198 if (encrypted != SECSuccess) {
199 LOG(ERROR) << "Error during encryption.";
200 return false;
201 }
202 encrypted_output->assign(rsa_output.get(),
203 rsa_output.get() + encrypted_length);
204 return true;
205 }
206
DecryptByteString(const std::string & private_key_pem,const std::vector<uint8> & encrypted_data,std::string * decrypted_output)207 bool NetworkingPrivateCrypto::DecryptByteString(
208 const std::string& private_key_pem,
209 const std::vector<uint8>& encrypted_data,
210 std::string* decrypted_output) {
211 crypto::EnsureNSSInit();
212
213 std::vector<uint8> private_key_data;
214 if (!GetDERFromPEM(private_key_pem, "PRIVATE KEY", &private_key_data)) {
215 LOG(ERROR) << "Failed to parse private key PEM.";
216 return false;
217 }
218 scoped_ptr<crypto::RSAPrivateKey> private_key(
219 crypto::RSAPrivateKey::CreateFromPrivateKeyInfo(private_key_data));
220 if (!private_key || !private_key->public_key()) {
221 LOG(ERROR) << "Failed to parse private key DER.";
222 return false;
223 }
224
225 size_t encrypted_length = SECKEY_SignatureLen(private_key->public_key());
226 scoped_ptr<unsigned char[]> rsa_output(new unsigned char[encrypted_length]);
227 unsigned int output_length = 0;
228 SECStatus decrypted =
229 PK11_PrivDecryptPKCS1(private_key->key(),
230 rsa_output.get(),
231 &output_length,
232 encrypted_length,
233 const_cast<unsigned char*>(encrypted_data.data()),
234 encrypted_data.size());
235 if (decrypted != SECSuccess) {
236 LOG(ERROR) << "Error during decryption.";
237 return false;
238 }
239 decrypted_output->assign(reinterpret_cast<char*>(rsa_output.get()),
240 output_length);
241 return true;
242 }
243