1 /*
2 * Copyright 2004 The WebRTC Project Authors. All rights reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 // Handling of certificates and keypairs for SSLStreamAdapter's peer mode.
12 #include "rtc_base/ssl_identity.h"
13
14 #include <openssl/ossl_typ.h>
15 #include <string.h>
16 #include <time.h>
17
18 #include "absl/strings/string_view.h"
19 #include "rtc_base/checks.h"
20 #ifdef OPENSSL_IS_BORINGSSL
21 #include "rtc_base/boringssl_identity.h"
22 #else
23 #include "rtc_base/openssl_identity.h"
24 #endif
25 #include "rtc_base/ssl_certificate.h"
26 #include "rtc_base/strings/string_builder.h"
27 #include "rtc_base/third_party/base64/base64.h"
28 #include "rtc_base/time_utils.h"
29
30 namespace rtc {
31
32 //////////////////////////////////////////////////////////////////////
33 // Helper Functions
34 //////////////////////////////////////////////////////////////////////
35
36 namespace {
37 // Read `n` bytes from ASN1 number string at *`pp` and return the numeric value.
38 // Update *`pp` and *`np` to reflect number of read bytes.
39 // TODO(bugs.webrtc.org/9860) - Remove this code.
ASN1ReadInt(const unsigned char ** pp,size_t * np,size_t n)40 inline int ASN1ReadInt(const unsigned char** pp, size_t* np, size_t n) {
41 const unsigned char* p = *pp;
42 int x = 0;
43 for (size_t i = 0; i < n; i++) {
44 x = 10 * x + p[i] - '0';
45 }
46 *pp = p + n;
47 *np = *np - n;
48 return x;
49 }
50
51 } // namespace
52
53 // TODO(bugs.webrtc.org/9860) - Remove this code.
ASN1TimeToSec(const unsigned char * s,size_t length,bool long_format)54 int64_t ASN1TimeToSec(const unsigned char* s, size_t length, bool long_format) {
55 size_t bytes_left = length;
56 // Make sure the string ends with Z. Doing it here protects the strspn call
57 // from running off the end of the string in Z's absense.
58 if (length == 0 || s[length - 1] != 'Z') {
59 return -1;
60 }
61 // Make sure we only have ASCII digits so that we don't need to clutter the
62 // code below and ASN1ReadInt with error checking.
63 size_t n = strspn(reinterpret_cast<const char*>(s), "0123456789");
64 if (n + 1 != length) {
65 return -1;
66 }
67 // Read out ASN1 year, in either 2-char "UTCTIME" or 4-char "GENERALIZEDTIME"
68 // format. Both format use UTC in this context.
69 int year = 0;
70 if (long_format) {
71 // ASN1 format: yyyymmddhh[mm[ss[.fff]]]Z where the Z is literal, but
72 // RFC 5280 requires us to only support exactly yyyymmddhhmmssZ.
73 if (bytes_left < 11) {
74 return -1;
75 }
76 year = ASN1ReadInt(&s, &bytes_left, 4);
77 year -= 1900;
78 } else {
79 // ASN1 format: yymmddhhmm[ss]Z where the Z is literal, but RFC 5280
80 // requires us to only support exactly yymmddhhmmssZ.
81 if (bytes_left < 9) {
82 return -1;
83 }
84 year = ASN1ReadInt(&s, &bytes_left, 2);
85 // Per RFC 5280 4.1.2.5.1
86 if (year < 50) {
87 year += 100;
88 }
89 }
90
91 // Read out remaining ASN1 time data and store it in `tm` in documented
92 // std::tm format.
93 tm tm;
94 tm.tm_year = year;
95 tm.tm_mon = ASN1ReadInt(&s, &bytes_left, 2) - 1;
96 tm.tm_mday = ASN1ReadInt(&s, &bytes_left, 2);
97 tm.tm_hour = ASN1ReadInt(&s, &bytes_left, 2);
98 tm.tm_min = ASN1ReadInt(&s, &bytes_left, 2);
99 tm.tm_sec = ASN1ReadInt(&s, &bytes_left, 2);
100
101 // Now just Z should remain. Its existence was asserted above.
102 if (bytes_left != 1) {
103 return -1;
104 }
105 return TmToSeconds(tm);
106 }
107
108 //////////////////////////////////////////////////////////////////////
109 // KeyParams
110 //////////////////////////////////////////////////////////////////////
111
112 const char kPemTypeCertificate[] = "CERTIFICATE";
113 const char kPemTypeRsaPrivateKey[] = "RSA PRIVATE KEY";
114 const char kPemTypeEcPrivateKey[] = "EC PRIVATE KEY";
115
KeyParams(KeyType key_type)116 KeyParams::KeyParams(KeyType key_type) {
117 if (key_type == KT_ECDSA) {
118 type_ = KT_ECDSA;
119 params_.curve = EC_NIST_P256;
120 } else if (key_type == KT_RSA) {
121 type_ = KT_RSA;
122 params_.rsa.mod_size = kRsaDefaultModSize;
123 params_.rsa.pub_exp = kRsaDefaultExponent;
124 } else {
125 RTC_DCHECK_NOTREACHED();
126 }
127 }
128
129 // static
RSA(int mod_size,int pub_exp)130 KeyParams KeyParams::RSA(int mod_size, int pub_exp) {
131 KeyParams kt(KT_RSA);
132 kt.params_.rsa.mod_size = mod_size;
133 kt.params_.rsa.pub_exp = pub_exp;
134 return kt;
135 }
136
137 // static
ECDSA(ECCurve curve)138 KeyParams KeyParams::ECDSA(ECCurve curve) {
139 KeyParams kt(KT_ECDSA);
140 kt.params_.curve = curve;
141 return kt;
142 }
143
IsValid() const144 bool KeyParams::IsValid() const {
145 if (type_ == KT_RSA) {
146 return (params_.rsa.mod_size >= kRsaMinModSize &&
147 params_.rsa.mod_size <= kRsaMaxModSize &&
148 params_.rsa.pub_exp > params_.rsa.mod_size);
149 } else if (type_ == KT_ECDSA) {
150 return (params_.curve == EC_NIST_P256);
151 }
152 return false;
153 }
154
rsa_params() const155 RSAParams KeyParams::rsa_params() const {
156 RTC_DCHECK(type_ == KT_RSA);
157 return params_.rsa;
158 }
159
ec_curve() const160 ECCurve KeyParams::ec_curve() const {
161 RTC_DCHECK(type_ == KT_ECDSA);
162 return params_.curve;
163 }
164
IntKeyTypeFamilyToKeyType(int key_type_family)165 KeyType IntKeyTypeFamilyToKeyType(int key_type_family) {
166 return static_cast<KeyType>(key_type_family);
167 }
168
169 //////////////////////////////////////////////////////////////////////
170 // SSLIdentity
171 //////////////////////////////////////////////////////////////////////
172
PemToDer(absl::string_view pem_type,absl::string_view pem_string,std::string * der)173 bool SSLIdentity::PemToDer(absl::string_view pem_type,
174 absl::string_view pem_string,
175 std::string* der) {
176 // Find the inner body. We need this to fulfill the contract of returning
177 // pem_length.
178 std::string pem_type_str(pem_type);
179 size_t header = pem_string.find("-----BEGIN " + pem_type_str + "-----");
180 if (header == absl::string_view::npos) {
181 return false;
182 }
183 size_t body = pem_string.find('\n', header);
184 if (body == absl::string_view::npos) {
185 return false;
186 }
187 size_t trailer = pem_string.find("-----END " + pem_type_str + "-----");
188 if (trailer == absl::string_view::npos) {
189 return false;
190 }
191 std::string inner(pem_string.substr(body + 1, trailer - (body + 1)));
192 *der = Base64::Decode(inner, Base64::DO_PARSE_WHITE | Base64::DO_PAD_ANY |
193 Base64::DO_TERM_BUFFER);
194 return true;
195 }
196
DerToPem(absl::string_view pem_type,const unsigned char * data,size_t length)197 std::string SSLIdentity::DerToPem(absl::string_view pem_type,
198 const unsigned char* data,
199 size_t length) {
200 rtc::StringBuilder result;
201 result << "-----BEGIN " << pem_type << "-----\n";
202
203 std::string b64_encoded;
204 Base64::EncodeFromArray(data, length, &b64_encoded);
205 // Divide the Base-64 encoded data into 64-character chunks, as per 4.3.2.4
206 // of RFC 1421.
207 static const size_t kChunkSize = 64;
208 size_t chunks = (b64_encoded.size() + (kChunkSize - 1)) / kChunkSize;
209 for (size_t i = 0, chunk_offset = 0; i < chunks;
210 ++i, chunk_offset += kChunkSize) {
211 result << b64_encoded.substr(chunk_offset, kChunkSize);
212 result << "\n";
213 }
214 result << "-----END " << pem_type << "-----\n";
215 return result.Release();
216 }
217
218 // static
Create(absl::string_view common_name,const KeyParams & key_param,time_t certificate_lifetime)219 std::unique_ptr<SSLIdentity> SSLIdentity::Create(absl::string_view common_name,
220 const KeyParams& key_param,
221 time_t certificate_lifetime) {
222 #ifdef OPENSSL_IS_BORINGSSL
223 return BoringSSLIdentity::CreateWithExpiration(common_name, key_param,
224 certificate_lifetime);
225 #else
226 return OpenSSLIdentity::CreateWithExpiration(common_name, key_param,
227 certificate_lifetime);
228 #endif
229 }
230
231 // static
Create(absl::string_view common_name,const KeyParams & key_param)232 std::unique_ptr<SSLIdentity> SSLIdentity::Create(absl::string_view common_name,
233 const KeyParams& key_param) {
234 return Create(common_name, key_param, kDefaultCertificateLifetimeInSeconds);
235 }
236
237 // static
Create(absl::string_view common_name,KeyType key_type)238 std::unique_ptr<SSLIdentity> SSLIdentity::Create(absl::string_view common_name,
239 KeyType key_type) {
240 return Create(common_name, KeyParams(key_type),
241 kDefaultCertificateLifetimeInSeconds);
242 }
243
244 // static
CreateForTest(const SSLIdentityParams & params)245 std::unique_ptr<SSLIdentity> SSLIdentity::CreateForTest(
246 const SSLIdentityParams& params) {
247 #ifdef OPENSSL_IS_BORINGSSL
248 return BoringSSLIdentity::CreateForTest(params);
249 #else
250 return OpenSSLIdentity::CreateForTest(params);
251 #endif
252 }
253
254 // Construct an identity from a private key and a certificate.
255 // static
CreateFromPEMStrings(absl::string_view private_key,absl::string_view certificate)256 std::unique_ptr<SSLIdentity> SSLIdentity::CreateFromPEMStrings(
257 absl::string_view private_key,
258 absl::string_view certificate) {
259 #ifdef OPENSSL_IS_BORINGSSL
260 return BoringSSLIdentity::CreateFromPEMStrings(private_key, certificate);
261 #else
262 return OpenSSLIdentity::CreateFromPEMStrings(private_key, certificate);
263 #endif
264 }
265
266 // Construct an identity from a private key and a certificate chain.
267 // static
CreateFromPEMChainStrings(absl::string_view private_key,absl::string_view certificate_chain)268 std::unique_ptr<SSLIdentity> SSLIdentity::CreateFromPEMChainStrings(
269 absl::string_view private_key,
270 absl::string_view certificate_chain) {
271 #ifdef OPENSSL_IS_BORINGSSL
272 return BoringSSLIdentity::CreateFromPEMChainStrings(private_key,
273 certificate_chain);
274 #else
275 return OpenSSLIdentity::CreateFromPEMChainStrings(private_key,
276 certificate_chain);
277 #endif
278 }
279
operator ==(const SSLIdentity & a,const SSLIdentity & b)280 bool operator==(const SSLIdentity& a, const SSLIdentity& b) {
281 #ifdef OPENSSL_IS_BORINGSSL
282 return static_cast<const BoringSSLIdentity&>(a) ==
283 static_cast<const BoringSSLIdentity&>(b);
284 #else
285 return static_cast<const OpenSSLIdentity&>(a) ==
286 static_cast<const OpenSSLIdentity&>(b);
287 #endif
288 }
operator !=(const SSLIdentity & a,const SSLIdentity & b)289 bool operator!=(const SSLIdentity& a, const SSLIdentity& b) {
290 return !(a == b);
291 }
292
293 } // namespace rtc
294