1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
|
/*
* Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Certificate.h"
#include <AK/Debug.h>
#include <LibCrypto/ASN1/ASN1.h>
#include <LibCrypto/ASN1/DER.h>
#include <LibCrypto/ASN1/PEM.h>
namespace TLS {
constexpr static Array<int, 4>
common_name_oid { 2, 5, 4, 3 },
country_name_oid { 2, 5, 4, 6 },
locality_name_oid { 2, 5, 4, 7 },
organization_name_oid { 2, 5, 4, 10 },
organizational_unit_name_oid { 2, 5, 4, 11 };
constexpr static Array<int, 7>
rsa_encryption_oid { 1, 2, 840, 113549, 1, 1, 1 },
rsa_md5_encryption_oid { 1, 2, 840, 113549, 1, 1, 4 },
rsa_sha1_encryption_oid { 1, 2, 840, 113549, 1, 1, 5 },
rsa_sha256_encryption_oid { 1, 2, 840, 113549, 1, 1, 11 },
rsa_sha384_encryption_oid { 1, 2, 840, 113549, 1, 1, 12 },
rsa_sha512_encryption_oid { 1, 2, 840, 113549, 1, 1, 13 };
constexpr static Array<int, 4>
subject_alternative_name_oid { 2, 5, 29, 17 };
Optional<Certificate> Certificate::parse_asn1(ReadonlyBytes buffer, bool)
{
#define ENTER_SCOPE_WITHOUT_TYPECHECK(scope) \
do { \
if (auto result = decoder.enter(); result.has_value()) { \
dbgln_if(TLS_DEBUG, "Failed to enter object (" scope "): {}", result.value()); \
return {}; \
} \
} while (0)
#define ENTER_SCOPE_OR_FAIL(kind_name, scope) \
do { \
if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::kind_name) { \
if constexpr (TLS_DEBUG) { \
if (tag.is_error()) \
dbgln(scope " data was invalid: {}", tag.error()); \
else \
dbgln(scope " data was not of kind " #kind_name); \
} \
return {}; \
} \
ENTER_SCOPE_WITHOUT_TYPECHECK(scope); \
} while (0)
#define EXIT_SCOPE(scope) \
do { \
if (auto error = decoder.leave(); error.has_value()) { \
dbgln_if(TLS_DEBUG, "Error while exiting scope " scope ": {}", error.value()); \
return {}; \
} \
} while (0)
#define ENSURE_OBJECT_KIND(_kind_name, scope) \
do { \
if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::_kind_name) { \
if constexpr (TLS_DEBUG) { \
if (tag.is_error()) \
dbgln(scope " data was invalid: {}", tag.error()); \
else \
dbgln(scope " data was not of kind " #_kind_name ", it was {}", Crypto::ASN1::kind_name(tag.value().kind)); \
} \
return {}; \
} \
} while (0)
#define READ_OBJECT_OR_FAIL(kind_name, type_name, value_name, scope) \
auto value_name##_result = decoder.read<type_name>(Crypto::ASN1::Class::Universal, Crypto::ASN1::Kind::kind_name); \
if (value_name##_result.is_error()) { \
dbgln_if(TLS_DEBUG, scope " read of kind " #kind_name " failed: {}", value_name##_result.error()); \
return {}; \
} \
auto value_name = value_name##_result.release_value();
#define DROP_OBJECT_OR_FAIL(scope) \
do { \
if (auto error = decoder.drop(); error.has_value()) { \
dbgln_if(TLS_DEBUG, scope " read failed: {}", error.value()); \
} \
} while (0)
Certificate certificate;
Crypto::ASN1::Decoder decoder { buffer };
// Certificate ::= Sequence {
// certificate TBSCertificate,
// signature_algorithm AlgorithmIdentifier,
// signature_value BitString
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate");
// TBSCertificate ::= Sequence {
// version (0) EXPLICIT Version DEFAULT v1,
// serial_number CertificateSerialNumber,
// signature AlgorithmIdentifier,
// issuer Name,
// validity Validity,
// subject Name,
// subject_public_key_info SubjectPublicKeyInfo,
// issuer_unique_id (1) IMPLICIT UniqueIdentifier OPTIONAL (if present, version > v1),
// subject_unique_id (2) IMPLICIT UniqueIdentifier OPTIONAL (if present, version > v1),
// extensions (3) EXPLICIT Extensions OPTIONAL (if present, version > v2)
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate");
// version
{
// Version :: Integer { v1(0), v2(1), v3(2) } (Optional)
if (auto tag = decoder.peek(); !tag.is_error() && tag.value().type == Crypto::ASN1::Type::Constructed) {
ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::version");
READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::version");
if (!(value < 3)) {
dbgln_if(TLS_DEBUG, "Certificate::version Invalid value for version: {}", value.to_base(10));
return {};
}
certificate.version = value.words()[0];
EXIT_SCOPE("Certificate::version");
} else {
certificate.version = 0;
}
}
// serial_number
{
// CertificateSerialNumber :: Integer
READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::serial_number");
certificate.serial_number = move(value);
}
auto parse_algorithm_identifier = [&](CertificateKeyAlgorithm& field) -> Optional<bool> {
// AlgorithmIdentifier ::= Sequence {
// algorithm ObjectIdentifier,
// parameters ANY OPTIONAL
// }
ENTER_SCOPE_OR_FAIL(Sequence, "AlgorithmIdentifier");
READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, identifier, "AlgorithmIdentifier::algorithm");
if (identifier == rsa_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_RSA;
else if (identifier == rsa_md5_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_MD5;
else if (identifier == rsa_sha1_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA1;
else if (identifier == rsa_sha256_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA256;
else if (identifier == rsa_sha384_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA384;
else if (identifier == rsa_sha512_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA512;
else
return {};
EXIT_SCOPE("AlgorithmIdentifier");
return true;
};
// signature
{
if (!parse_algorithm_identifier(certificate.algorithm).has_value())
return {};
}
auto parse_name = [&](auto& name_struct) -> Optional<bool> {
// Name ::= Choice {
// rdn_sequence RDNSequence
// } // NOTE: since this is the only alternative, there's no index
// RDNSequence ::= Sequence OF RelativeDistinguishedName
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject");
// RelativeDistinguishedName ::= Set OF AttributeTypeAndValue
// AttributeTypeAndValue ::= Sequence {
// type AttributeType,
// value AttributeValue
// }
// AttributeType ::= ObjectIdentifier
// AttributeValue ::= Any
while (!decoder.eof()) {
// Parse only the the required fields, and ignore the rest.
ENTER_SCOPE_OR_FAIL(Set, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
while (!decoder.eof()) {
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
ENSURE_OBJECT_KIND(ObjectIdentifier, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type");
if (auto type_identifier_or_error = decoder.read<Vector<int>>(); !type_identifier_or_error.is_error()) {
// Figure out what type of identifier this is
auto& identifier = type_identifier_or_error.value();
if (identifier == common_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.subject = name;
} else if (identifier == country_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.country = name;
} else if (identifier == locality_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.location = name;
} else if (identifier == organization_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.entity = name;
} else if (identifier == organizational_unit_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.unit = name;
}
} else {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type data was invalid: {}", type_identifier_or_error.error());
return {};
}
EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
}
EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
}
EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject");
return true;
};
// issuer
{
if (!parse_name(certificate.issuer).has_value())
return {};
}
// validity
{
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Validity");
auto parse_time = [&](Core::DateTime& datetime) -> Optional<bool> {
// Time ::= Choice {
// utc_time UTCTime,
// general_time GeneralizedTime
// }
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time failed to read tag: {}", tag.error());
return {};
};
if (tag.value().kind == Crypto::ASN1::Kind::UTCTime) {
READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
auto result = Crypto::ASN1::parse_utc_time(time);
if (!result.has_value()) {
dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid UTC Time: {}", time);
return {};
}
datetime = result.release_value();
return true;
}
if (tag.value().kind == Crypto::ASN1::Kind::GeneralizedTime) {
READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
auto result = Crypto::ASN1::parse_generalized_time(time);
if (!result.has_value()) {
dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid Generalized Time: {}", time);
return {};
}
datetime = result.release_value();
return true;
}
dbgln_if(1, "Unrecognised Time format {}", Crypto::ASN1::kind_name(tag.value().kind));
return {};
};
if (!parse_time(certificate.not_before).has_value())
return {};
if (!parse_time(certificate.not_after).has_value())
return {};
EXIT_SCOPE("Certificate::TBSCertificate::Validity");
}
// subject
{
if (!parse_name(certificate.subject).has_value())
return {};
}
// subject_public_key_info
{
// SubjectPublicKeyInfo ::= Sequence {
// algorithm AlgorithmIdentifier,
// subject_public_key BitString
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::subject_public_key_info");
if (!parse_algorithm_identifier(certificate.key_algorithm).has_value())
return {};
READ_OBJECT_OR_FAIL(BitString, const BitmapView, value, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info");
// Note: Once we support other kinds of keys, make sure to check the kind here!
auto key = Crypto::PK::RSA::parse_rsa_key({ value.data(), value.size_in_bytes() });
if (!key.public_key.length()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info: Invalid key");
return {};
}
certificate.public_key = move(key.public_key);
EXIT_SCOPE("Certificate::TBSCertificate::subject_public_key_info");
}
auto parse_unique_identifier = [&]() -> Optional<bool> {
if (certificate.version == 0)
return true;
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
return {};
}
// The spec says to just ignore these.
if (static_cast<u8>(tag.value().kind) == 1 || static_cast<u8>(tag.value().kind) == 2)
DROP_OBJECT_OR_FAIL("UniqueIdentifier");
return true;
};
// issuer_unique_identifier
{
if (!parse_unique_identifier().has_value())
return {};
}
// subject_unique_identifier
{
if (!parse_unique_identifier().has_value())
return {};
}
// extensions
{
if (certificate.version == 2) {
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
return {};
}
if (static_cast<u8>(tag.value().kind) == 3) {
// Extensions ::= Sequence OF Extension
// Extension ::= Sequence {
// extension_id ObjectIdentifier,
// critical Boolean DEFAULT false,
// extension_value OctetString (DER-encoded)
// }
ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::TBSCertificate::Extensions(IMPLICIT)");
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions");
while (!decoder.eof()) {
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension");
READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, extension_id, "Certificate::TBSCertificate::Extensions::$::Extension::extension_id");
bool is_critical = false;
if (auto tag = decoder.peek(); !tag.is_error() && tag.value().kind == Crypto::ASN1::Kind::Boolean) {
// Read the 'critical' property
READ_OBJECT_OR_FAIL(Boolean, bool, critical, "Certificate::TBSCertificate::Extensions::$::Extension::critical");
is_critical = critical;
}
READ_OBJECT_OR_FAIL(OctetString, StringView, extension_value, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value");
// Figure out what this extension is.
if (extension_id == subject_alternative_name_oid) {
Crypto::ASN1::Decoder decoder { extension_value.bytes() };
// SubjectAlternativeName ::= GeneralNames
// GeneralNames ::= Sequence OF GeneralName
// GeneralName ::= CHOICE {
// other_name (0) OtherName,
// rfc_822_name (1) IA5String,
// dns_name (2) IA5String,
// x400Address (3) ORAddress,
// directory_name (4) Name,
// edi_party_name (5) EDIPartyName,
// uri (6) IA5String,
// ip_address (7) OctetString,
// registered_id (8) ObjectIdentifier,
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName");
while (!decoder.eof()) {
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$ could not read tag: {}", tag.error());
return {};
}
auto tag_value = static_cast<u8>(tag.value().kind);
switch (tag_value) {
case 0:
// OtherName
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::OtherName");
break;
case 1:
// RFC 822 name
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RFC822Name");
break;
case 2: {
// DNS Name
READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::Name");
certificate.SAN.append(name);
break;
}
case 3:
// x400Address
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::X400Address");
break;
case 4:
// Directory name
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DirectoryName");
break;
case 5:
// edi party name
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::EDIPartyName");
break;
case 6: {
// URI
READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::URI");
certificate.SAN.append(name);
break;
}
case 7:
// IP Address
// We can't handle these.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::IPAddress");
break;
case 8:
// Registered ID
// We can't handle these.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RegisteredID");
break;
default:
dbgln_if(TLS_DEBUG, "Unknown tag in SAN choice {}", tag_value);
if (is_critical)
return {};
else
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::???");
}
}
}
EXIT_SCOPE("Certificate::TBSCertificate::Extensions::$::Extension");
}
EXIT_SCOPE("Certificate::TBSCertificate::Extensions");
EXIT_SCOPE("Certificate::TBSCertificate::Extensions(IMPLICIT)");
}
}
}
// Just ignore the rest of the data for now.
EXIT_SCOPE("Certificate::TBSCertificate");
EXIT_SCOPE("Certificate");
dbgln_if(TLS_DEBUG, "Certificate issued for {} by {}", certificate.subject.subject, certificate.issuer.subject);
return certificate;
#undef DROP_OBJECT_OR_FAIL
#undef ENSURE_OBJECT_KIND
#undef ENTER_SCOPE_OR_FAIL
#undef ENTER_SCOPE_WITHOUT_TYPECHECK
#undef EXIT_SCOPE
#undef READ_OBJECT_OR_FAIL
}
}
|
