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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 "net/cert/x509_certificate.h"
6 
7 #include <limits.h>
8 #include <stdlib.h>
9 
10 #include <memory>
11 #include <string>
12 #include <vector>
13 
14 #include "base/base64.h"
15 #include "base/containers/contains.h"
16 #include "base/containers/span.h"
17 #include "base/logging.h"
18 #include "base/numerics/safe_conversions.h"
19 #include "base/pickle.h"
20 #include "base/strings/string_piece.h"
21 #include "base/strings/string_util.h"
22 #include "base/time/time.h"
23 #include "build/build_config.h"
24 #include "crypto/openssl_util.h"
25 #include "net/base/ip_address.h"
26 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
27 #include "net/base/tracing.h"
28 #include "net/base/url_util.h"
29 #include "net/cert/asn1_util.h"
30 #include "net/cert/pem.h"
31 #include "net/cert/pki/cert_errors.h"
32 #include "net/cert/pki/name_constraints.h"
33 #include "net/cert/pki/parsed_certificate.h"
34 #include "net/cert/pki/signature_algorithm.h"
35 #include "net/cert/pki/verify_certificate_chain.h"
36 #include "net/cert/pki/verify_name_match.h"
37 #include "net/cert/pki/verify_signed_data.h"
38 #include "net/cert/x509_util.h"
39 #include "net/der/encode_values.h"
40 #include "net/der/parser.h"
41 #include "net/dns/dns_util.h"
42 #include "third_party/boringssl/src/include/openssl/evp.h"
43 #include "third_party/boringssl/src/include/openssl/pool.h"
44 #include "third_party/boringssl/src/include/openssl/sha.h"
45 #include "url/url_canon.h"
46 
47 namespace net {
48 
49 namespace {
50 
51 // Indicates the order to use when trying to decode binary data, which is
52 // based on (speculation) as to what will be most common -> least common
53 const X509Certificate::Format kFormatDecodePriority[] = {
54   X509Certificate::FORMAT_SINGLE_CERTIFICATE,
55   X509Certificate::FORMAT_PKCS7
56 };
57 
58 // The PEM block header used for DER certificates
59 const char kCertificateHeader[] = "CERTIFICATE";
60 // The PEM block header used for PKCS#7 data
61 const char kPKCS7Header[] = "PKCS7";
62 
63 // Utility to split |src| on the first occurrence of |c|, if any. |right| will
64 // either be empty if |c| was not found, or will contain the remainder of the
65 // string including the split character itself.
SplitOnChar(base::StringPiece src,char c,base::StringPiece * left,base::StringPiece * right)66 void SplitOnChar(base::StringPiece src,
67                  char c,
68                  base::StringPiece* left,
69                  base::StringPiece* right) {
70   size_t pos = src.find(c);
71   if (pos == base::StringPiece::npos) {
72     *left = src;
73     *right = base::StringPiece();
74   } else {
75     *left = src.substr(0, pos);
76     *right = src.substr(pos);
77   }
78 }
79 
80 // Sets |value| to the Value from a DER Sequence Tag-Length-Value and return
81 // true, or return false if the TLV was not a valid DER Sequence.
ParseSequenceValue(const der::Input & tlv,der::Input * value)82 [[nodiscard]] bool ParseSequenceValue(const der::Input& tlv,
83                                       der::Input* value) {
84   der::Parser parser(tlv);
85   return parser.ReadTag(der::kSequence, value) && !parser.HasMore();
86 }
87 
88 // Normalize |cert|'s Issuer and store it in |out_normalized_issuer|, returning
89 // true on success or false if there was a parsing error.
GetNormalizedCertIssuer(CRYPTO_BUFFER * cert,std::string * out_normalized_issuer)90 bool GetNormalizedCertIssuer(CRYPTO_BUFFER* cert,
91                              std::string* out_normalized_issuer) {
92   der::Input tbs_certificate_tlv;
93   der::Input signature_algorithm_tlv;
94   der::BitString signature_value;
95   if (!ParseCertificate(
96           der::Input(CRYPTO_BUFFER_data(cert), CRYPTO_BUFFER_len(cert)),
97           &tbs_certificate_tlv, &signature_algorithm_tlv, &signature_value,
98           nullptr)) {
99     return false;
100   }
101   ParsedTbsCertificate tbs;
102   if (!ParseTbsCertificate(tbs_certificate_tlv,
103                            x509_util::DefaultParseCertificateOptions(), &tbs,
104                            nullptr))
105     return false;
106 
107   der::Input issuer_value;
108   if (!ParseSequenceValue(tbs.issuer_tlv, &issuer_value))
109     return false;
110 
111   CertErrors errors;
112   return NormalizeName(issuer_value, out_normalized_issuer, &errors);
113 }
114 
CreateCertBufferFromBytesWithSanityCheck(base::span<const uint8_t> data)115 bssl::UniquePtr<CRYPTO_BUFFER> CreateCertBufferFromBytesWithSanityCheck(
116     base::span<const uint8_t> data) {
117   der::Input tbs_certificate_tlv;
118   der::Input signature_algorithm_tlv;
119   der::BitString signature_value;
120   // Do a bare minimum of DER parsing here to see if the input looks
121   // certificate-ish.
122   if (!ParseCertificate(der::Input(data.data(), data.size()),
123                         &tbs_certificate_tlv, &signature_algorithm_tlv,
124                         &signature_value, nullptr)) {
125     return nullptr;
126   }
127   return x509_util::CreateCryptoBuffer(data);
128 }
129 
130 }  // namespace
131 
132 // static
CreateFromBuffer(bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates)133 scoped_refptr<X509Certificate> X509Certificate::CreateFromBuffer(
134     bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,
135     std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates) {
136   DCHECK(cert_buffer);
137   auto cert = base::WrapRefCounted(
138       new X509Certificate(std::move(cert_buffer), std::move(intermediates)));
139   if (!cert->cert_buffer())
140     return nullptr;  // Initialize() failed.
141   return cert;
142 }
143 
144 // static
CreateFromBufferUnsafeOptions(bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates,UnsafeCreateOptions options)145 scoped_refptr<X509Certificate> X509Certificate::CreateFromBufferUnsafeOptions(
146     bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,
147     std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates,
148     UnsafeCreateOptions options) {
149   DCHECK(cert_buffer);
150   auto cert = base::WrapRefCounted(new X509Certificate(
151       std::move(cert_buffer), std::move(intermediates), options));
152   if (!cert->cert_buffer())
153     return nullptr;  // Initialize() failed.
154   return cert;
155 }
156 
157 // static
CreateFromDERCertChain(const std::vector<base::StringPiece> & der_certs)158 scoped_refptr<X509Certificate> X509Certificate::CreateFromDERCertChain(
159     const std::vector<base::StringPiece>& der_certs) {
160   return CreateFromDERCertChainUnsafeOptions(der_certs, {});
161 }
162 
163 // static
164 scoped_refptr<X509Certificate>
CreateFromDERCertChainUnsafeOptions(const std::vector<base::StringPiece> & der_certs,UnsafeCreateOptions options)165 X509Certificate::CreateFromDERCertChainUnsafeOptions(
166     const std::vector<base::StringPiece>& der_certs,
167     UnsafeCreateOptions options) {
168   TRACE_EVENT0("io", "X509Certificate::CreateFromDERCertChain");
169   if (der_certs.empty())
170     return nullptr;
171 
172   std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediate_ca_certs;
173   intermediate_ca_certs.reserve(der_certs.size() - 1);
174   for (size_t i = 1; i < der_certs.size(); i++) {
175     intermediate_ca_certs.push_back(
176         x509_util::CreateCryptoBuffer(der_certs[i]));
177   }
178 
179   return CreateFromBufferUnsafeOptions(
180       x509_util::CreateCryptoBuffer(der_certs[0]),
181       std::move(intermediate_ca_certs), options);
182 }
183 
184 // static
CreateFromBytes(base::span<const uint8_t> data)185 scoped_refptr<X509Certificate> X509Certificate::CreateFromBytes(
186     base::span<const uint8_t> data) {
187   return CreateFromBytesUnsafeOptions(data, {});
188 }
189 
190 // static
CreateFromBytesUnsafeOptions(base::span<const uint8_t> data,UnsafeCreateOptions options)191 scoped_refptr<X509Certificate> X509Certificate::CreateFromBytesUnsafeOptions(
192     base::span<const uint8_t> data,
193     UnsafeCreateOptions options) {
194   scoped_refptr<X509Certificate> cert = CreateFromBufferUnsafeOptions(
195       x509_util::CreateCryptoBuffer(data), {}, options);
196   return cert;
197 }
198 
199 // static
CreateFromPickle(base::PickleIterator * pickle_iter)200 scoped_refptr<X509Certificate> X509Certificate::CreateFromPickle(
201     base::PickleIterator* pickle_iter) {
202   return CreateFromPickleUnsafeOptions(pickle_iter, {});
203 }
204 
205 // static
CreateFromPickleUnsafeOptions(base::PickleIterator * pickle_iter,UnsafeCreateOptions options)206 scoped_refptr<X509Certificate> X509Certificate::CreateFromPickleUnsafeOptions(
207     base::PickleIterator* pickle_iter,
208     UnsafeCreateOptions options) {
209   size_t chain_length = 0;
210   if (!pickle_iter->ReadLength(&chain_length))
211     return nullptr;
212 
213   std::vector<base::StringPiece> cert_chain;
214   const char* data = nullptr;
215   size_t data_length = 0;
216   for (size_t i = 0; i < chain_length; ++i) {
217     if (!pickle_iter->ReadData(&data, &data_length))
218       return nullptr;
219     cert_chain.emplace_back(data, data_length);
220   }
221   return CreateFromDERCertChainUnsafeOptions(cert_chain, options);
222 }
223 
224 // static
CreateCertificateListFromBytes(base::span<const uint8_t> data,int format)225 CertificateList X509Certificate::CreateCertificateListFromBytes(
226     base::span<const uint8_t> data,
227     int format) {
228   std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> certificates;
229 
230   // Check to see if it is in a PEM-encoded form. This check is performed
231   // first, as both OS X and NSS will both try to convert if they detect
232   // PEM encoding, except they don't do it consistently between the two.
233   base::StringPiece data_string(reinterpret_cast<const char*>(data.data()),
234                                 data.size());
235   std::vector<std::string> pem_headers;
236 
237   // To maintain compatibility with NSS/Firefox, CERTIFICATE is a universally
238   // valid PEM block header for any format.
239   pem_headers.push_back(kCertificateHeader);
240   if (format & FORMAT_PKCS7)
241     pem_headers.push_back(kPKCS7Header);
242 
243   PEMTokenizer pem_tokenizer(data_string, pem_headers);
244   while (pem_tokenizer.GetNext()) {
245     std::string decoded(pem_tokenizer.data());
246 
247     bssl::UniquePtr<CRYPTO_BUFFER> handle;
248     if (format & FORMAT_PEM_CERT_SEQUENCE) {
249       handle = CreateCertBufferFromBytesWithSanityCheck(
250           base::as_bytes(base::make_span(decoded)));
251     }
252     if (handle) {
253       // Parsed a DER encoded certificate. All PEM blocks that follow must
254       // also be DER encoded certificates wrapped inside of PEM blocks.
255       format = FORMAT_PEM_CERT_SEQUENCE;
256       certificates.push_back(std::move(handle));
257       continue;
258     }
259 
260     // If the first block failed to parse as a DER certificate, and
261     // formats other than PEM are acceptable, check to see if the decoded
262     // data is one of the accepted formats.
263     if (format & ~FORMAT_PEM_CERT_SEQUENCE) {
264       for (size_t i = 0;
265            certificates.empty() && i < std::size(kFormatDecodePriority); ++i) {
266         if (format & kFormatDecodePriority[i]) {
267           certificates = CreateCertBuffersFromBytes(
268               base::as_bytes(base::make_span(decoded)),
269               kFormatDecodePriority[i]);
270         }
271       }
272     }
273 
274     // Stop parsing after the first block for any format but a sequence of
275     // PEM-encoded DER certificates. The case of FORMAT_PEM_CERT_SEQUENCE
276     // is handled above, and continues processing until a certificate fails
277     // to parse.
278     break;
279   }
280 
281   // Try each of the formats, in order of parse preference, to see if |data|
282   // contains the binary representation of a Format, if it failed to parse
283   // as a PEM certificate/chain.
284   for (size_t i = 0;
285        certificates.empty() && i < std::size(kFormatDecodePriority); ++i) {
286     if (format & kFormatDecodePriority[i])
287       certificates = CreateCertBuffersFromBytes(data, kFormatDecodePriority[i]);
288   }
289 
290   CertificateList results;
291   // No certificates parsed.
292   if (certificates.empty())
293     return results;
294 
295   for (auto& it : certificates) {
296     scoped_refptr<X509Certificate> cert = CreateFromBuffer(std::move(it), {});
297     if (cert)
298       results.push_back(std::move(cert));
299   }
300 
301   return results;
302 }
303 
Persist(base::Pickle * pickle) const304 void X509Certificate::Persist(base::Pickle* pickle) const {
305   DCHECK(cert_buffer_);
306   // This would be an absolutely insane number of intermediates.
307   if (intermediate_ca_certs_.size() > static_cast<size_t>(INT_MAX) - 1) {
308     NOTREACHED();
309     return;
310   }
311   pickle->WriteInt(static_cast<int>(intermediate_ca_certs_.size() + 1));
312   pickle->WriteString(x509_util::CryptoBufferAsStringPiece(cert_buffer_.get()));
313   for (const auto& intermediate : intermediate_ca_certs_) {
314     pickle->WriteString(
315         x509_util::CryptoBufferAsStringPiece(intermediate.get()));
316   }
317 }
318 
GetSubjectAltName(std::vector<std::string> * dns_names,std::vector<std::string> * ip_addrs) const319 bool X509Certificate::GetSubjectAltName(
320     std::vector<std::string>* dns_names,
321     std::vector<std::string>* ip_addrs) const {
322   if (dns_names)
323     dns_names->clear();
324   if (ip_addrs)
325     ip_addrs->clear();
326 
327   der::Input tbs_certificate_tlv;
328   der::Input signature_algorithm_tlv;
329   der::BitString signature_value;
330   if (!ParseCertificate(der::Input(CRYPTO_BUFFER_data(cert_buffer_.get()),
331                                    CRYPTO_BUFFER_len(cert_buffer_.get())),
332                         &tbs_certificate_tlv, &signature_algorithm_tlv,
333                         &signature_value, nullptr)) {
334     return false;
335   }
336 
337   ParsedTbsCertificate tbs;
338   if (!ParseTbsCertificate(tbs_certificate_tlv,
339                            x509_util::DefaultParseCertificateOptions(), &tbs,
340                            nullptr))
341     return false;
342   if (!tbs.extensions_tlv)
343     return false;
344 
345   std::map<der::Input, ParsedExtension> extensions;
346   if (!ParseExtensions(tbs.extensions_tlv.value(), &extensions))
347     return false;
348 
349   ParsedExtension subject_alt_names_extension;
350   if (!ConsumeExtension(der::Input(kSubjectAltNameOid), &extensions,
351                         &subject_alt_names_extension)) {
352     return false;
353   }
354 
355   CertErrors errors;
356   std::unique_ptr<GeneralNames> subject_alt_names =
357       GeneralNames::Create(subject_alt_names_extension.value, &errors);
358   if (!subject_alt_names)
359     return false;
360 
361   if (dns_names) {
362     for (const auto& dns_name : subject_alt_names->dns_names)
363       dns_names->push_back(std::string(dns_name));
364   }
365   if (ip_addrs) {
366     for (const IPAddress& addr : subject_alt_names->ip_addresses) {
367       ip_addrs->push_back(
368           std::string(reinterpret_cast<const char*>(addr.bytes().data()),
369                       addr.bytes().size()));
370     }
371   }
372 
373   return !subject_alt_names->dns_names.empty() ||
374          !subject_alt_names->ip_addresses.empty();
375 }
376 
HasExpired() const377 bool X509Certificate::HasExpired() const {
378   return base::Time::Now() > valid_expiry();
379 }
380 
EqualsExcludingChain(const X509Certificate * other) const381 bool X509Certificate::EqualsExcludingChain(const X509Certificate* other) const {
382   return x509_util::CryptoBufferEqual(cert_buffer_.get(),
383                                       other->cert_buffer_.get());
384 }
385 
EqualsIncludingChain(const X509Certificate * other) const386 bool X509Certificate::EqualsIncludingChain(const X509Certificate* other) const {
387   if (intermediate_ca_certs_.size() != other->intermediate_ca_certs_.size() ||
388       !EqualsExcludingChain(other)) {
389     return false;
390   }
391   for (size_t i = 0; i < intermediate_ca_certs_.size(); ++i) {
392     if (!x509_util::CryptoBufferEqual(intermediate_ca_certs_[i].get(),
393                                       other->intermediate_ca_certs_[i].get())) {
394       return false;
395     }
396   }
397   return true;
398 }
399 
IsIssuedByEncoded(const std::vector<std::string> & valid_issuers) const400 bool X509Certificate::IsIssuedByEncoded(
401     const std::vector<std::string>& valid_issuers) const {
402   std::vector<std::string> normalized_issuers;
403   CertErrors errors;
404   for (const auto& raw_issuer : valid_issuers) {
405     der::Input issuer_value;
406     std::string normalized_issuer;
407     if (!ParseSequenceValue(der::Input(&raw_issuer), &issuer_value) ||
408         !NormalizeName(issuer_value, &normalized_issuer, &errors)) {
409       continue;
410     }
411     normalized_issuers.push_back(std::move(normalized_issuer));
412   }
413 
414   std::string normalized_cert_issuer;
415   if (!GetNormalizedCertIssuer(cert_buffer_.get(), &normalized_cert_issuer))
416     return false;
417   if (base::Contains(normalized_issuers, normalized_cert_issuer))
418     return true;
419 
420   for (const auto& intermediate : intermediate_ca_certs_) {
421     if (!GetNormalizedCertIssuer(intermediate.get(), &normalized_cert_issuer))
422       return false;
423     if (base::Contains(normalized_issuers, normalized_cert_issuer))
424       return true;
425   }
426   return false;
427 }
428 
429 // static
VerifyHostname(const std::string & hostname,const std::vector<std::string> & cert_san_dns_names,const std::vector<std::string> & cert_san_ip_addrs)430 bool X509Certificate::VerifyHostname(
431     const std::string& hostname,
432     const std::vector<std::string>& cert_san_dns_names,
433     const std::vector<std::string>& cert_san_ip_addrs) {
434   DCHECK(!hostname.empty());
435 
436   if (cert_san_dns_names.empty() && cert_san_ip_addrs.empty()) {
437     // Either a dNSName or iPAddress subjectAltName MUST be present in order
438     // to match, so fail quickly if not.
439     return false;
440   }
441 
442   // Perform name verification following http://tools.ietf.org/html/rfc6125.
443   // The terminology used in this method is as per that RFC:-
444   // Reference identifier == the host the local user/agent is intending to
445   //                         access, i.e. the thing displayed in the URL bar.
446   // Presented identifier(s) == name(s) the server knows itself as, in its cert.
447 
448   // CanonicalizeHost requires surrounding brackets to parse an IPv6 address.
449   const std::string host_or_ip = hostname.find(':') != std::string::npos ?
450       "[" + hostname + "]" : hostname;
451   url::CanonHostInfo host_info;
452   std::string reference_name = CanonicalizeHost(host_or_ip, &host_info);
453 
454   // If the host cannot be canonicalized, fail fast.
455   if (reference_name.empty())
456     return false;
457 
458   // Fully handle all cases where |hostname| contains an IP address.
459   if (host_info.IsIPAddress()) {
460     base::StringPiece ip_addr_string(
461         reinterpret_cast<const char*>(host_info.address),
462         host_info.AddressLength());
463     return base::Contains(cert_san_ip_addrs, ip_addr_string);
464   }
465 
466   // The host portion of a URL may support a variety of name resolution formats
467   // and services. However, the only supported name types in this code are IP
468   // addresses, which have been handled above via iPAddress subjectAltNames,
469   // and DNS names, via dNSName subjectAltNames.
470   // Validate that the host conforms to the DNS preferred name syntax, in
471   // either relative or absolute form, and exclude the "root" label for DNS.
472   if (reference_name == "." || !IsCanonicalizedHostCompliant(reference_name))
473     return false;
474 
475   // CanonicalizeHost does not normalize absolute vs relative DNS names. If
476   // the input name was absolute (included trailing .), normalize it as if it
477   // was relative.
478   if (reference_name.back() == '.')
479     reference_name.pop_back();
480 
481   // |reference_domain| is the remainder of |host| after the leading host
482   // component is stripped off, but includes the leading dot e.g.
483   // "www.f.com" -> ".f.com".
484   // If there is no meaningful domain part to |host| (e.g. it contains no dots)
485   // then |reference_domain| will be empty.
486   base::StringPiece reference_host, reference_domain;
487   SplitOnChar(reference_name, '.', &reference_host, &reference_domain);
488   bool allow_wildcards = false;
489   if (!reference_domain.empty()) {
490     DCHECK(base::StartsWith(reference_domain, "."));
491 
492     // Do not allow wildcards for public/ICANN registry controlled domains -
493     // that is, prevent *.com or *.co.uk as valid presented names, but do not
494     // prevent *.appspot.com (a private registry controlled domain).
495     // In addition, unknown top-level domains (such as 'intranet' domains or
496     // new TLDs/gTLDs not yet added to the registry controlled domain dataset)
497     // are also implicitly prevented.
498     // Because |reference_domain| must contain at least one name component that
499     // is not registry controlled, this ensures that all reference domains
500     // contain at least three domain components when using wildcards.
501     size_t registry_length =
502         registry_controlled_domains::GetCanonicalHostRegistryLength(
503             reference_name,
504             registry_controlled_domains::INCLUDE_UNKNOWN_REGISTRIES,
505             registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
506 
507     // Because |reference_name| was already canonicalized, the following
508     // should never happen.
509     CHECK_NE(std::string::npos, registry_length);
510 
511     // Account for the leading dot in |reference_domain|.
512     bool is_registry_controlled =
513         registry_length != 0 &&
514         registry_length == (reference_domain.size() - 1);
515 
516     // Additionally, do not attempt wildcard matching for purely numeric
517     // hostnames.
518     allow_wildcards =
519         !is_registry_controlled &&
520         reference_name.find_first_not_of("0123456789.") != std::string::npos;
521   }
522 
523   // Now step through the DNS names doing wild card comparison (if necessary)
524   // on each against the reference name.
525   for (const auto& cert_san_dns_name : cert_san_dns_names) {
526     // Catch badly corrupt cert names up front.
527     if (cert_san_dns_name.empty() ||
528         cert_san_dns_name.find('\0') != std::string::npos) {
529       continue;
530     }
531     std::string presented_name(base::ToLowerASCII(cert_san_dns_name));
532 
533     // Remove trailing dot, if any.
534     if (*presented_name.rbegin() == '.')
535       presented_name.resize(presented_name.length() - 1);
536 
537     // The hostname must be at least as long as the cert name it is matching,
538     // as we require the wildcard (if present) to match at least one character.
539     if (presented_name.length() > reference_name.length())
540       continue;
541 
542     base::StringPiece presented_host, presented_domain;
543     SplitOnChar(presented_name, '.', &presented_host, &presented_domain);
544 
545     if (presented_domain != reference_domain)
546       continue;
547 
548     if (presented_host != "*") {
549       if (presented_host == reference_host)
550         return true;
551       continue;
552     }
553 
554     if (!allow_wildcards)
555       continue;
556 
557     return true;
558   }
559   return false;
560 }
561 
VerifyNameMatch(const std::string & hostname) const562 bool X509Certificate::VerifyNameMatch(const std::string& hostname) const {
563   std::vector<std::string> dns_names, ip_addrs;
564   GetSubjectAltName(&dns_names, &ip_addrs);
565   return VerifyHostname(hostname, dns_names, ip_addrs);
566 }
567 
568 // static
GetPEMEncodedFromDER(base::StringPiece der_encoded,std::string * pem_encoded)569 bool X509Certificate::GetPEMEncodedFromDER(base::StringPiece der_encoded,
570                                            std::string* pem_encoded) {
571   if (der_encoded.empty())
572     return false;
573 
574   *pem_encoded = PEMEncode(der_encoded, "CERTIFICATE");
575   return true;
576 }
577 
578 // static
GetPEMEncoded(const CRYPTO_BUFFER * cert_buffer,std::string * pem_encoded)579 bool X509Certificate::GetPEMEncoded(const CRYPTO_BUFFER* cert_buffer,
580                                     std::string* pem_encoded) {
581   return GetPEMEncodedFromDER(x509_util::CryptoBufferAsStringPiece(cert_buffer),
582                               pem_encoded);
583 }
584 
GetPEMEncodedChain(std::vector<std::string> * pem_encoded) const585 bool X509Certificate::GetPEMEncodedChain(
586     std::vector<std::string>* pem_encoded) const {
587   std::vector<std::string> encoded_chain;
588   std::string pem_data;
589   if (!GetPEMEncoded(cert_buffer(), &pem_data))
590     return false;
591   encoded_chain.push_back(pem_data);
592   for (const auto& intermediate_ca_cert : intermediate_ca_certs_) {
593     if (!GetPEMEncoded(intermediate_ca_cert.get(), &pem_data))
594       return false;
595     encoded_chain.push_back(pem_data);
596   }
597   pem_encoded->swap(encoded_chain);
598   return true;
599 }
600 
601 // static
GetPublicKeyInfo(const CRYPTO_BUFFER * cert_buffer,size_t * size_bits,PublicKeyType * type)602 void X509Certificate::GetPublicKeyInfo(const CRYPTO_BUFFER* cert_buffer,
603                                        size_t* size_bits,
604                                        PublicKeyType* type) {
605   *type = kPublicKeyTypeUnknown;
606   *size_bits = 0;
607 
608   base::StringPiece spki;
609   if (!asn1::ExtractSPKIFromDERCert(
610           base::StringPiece(
611               reinterpret_cast<const char*>(CRYPTO_BUFFER_data(cert_buffer)),
612               CRYPTO_BUFFER_len(cert_buffer)),
613           &spki)) {
614     return;
615   }
616 
617   bssl::UniquePtr<EVP_PKEY> pkey;
618   crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
619   CBS cbs;
620   CBS_init(&cbs, reinterpret_cast<const uint8_t*>(spki.data()), spki.size());
621   pkey.reset(EVP_parse_public_key(&cbs));
622   if (!pkey)
623     return;
624 
625   switch (EVP_PKEY_id(pkey.get())) {
626     case EVP_PKEY_RSA:
627       *type = kPublicKeyTypeRSA;
628       break;
629     case EVP_PKEY_DSA:
630       *type = kPublicKeyTypeDSA;
631       break;
632     case EVP_PKEY_EC:
633       *type = kPublicKeyTypeECDSA;
634       break;
635     case EVP_PKEY_DH:
636       *type = kPublicKeyTypeDH;
637       break;
638   }
639   *size_bits = base::saturated_cast<size_t>(EVP_PKEY_bits(pkey.get()));
640 }
641 
642 // static
643 std::vector<bssl::UniquePtr<CRYPTO_BUFFER>>
CreateCertBuffersFromBytes(base::span<const uint8_t> data,Format format)644 X509Certificate::CreateCertBuffersFromBytes(base::span<const uint8_t> data,
645                                             Format format) {
646   std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> results;
647 
648   switch (format) {
649     case FORMAT_SINGLE_CERTIFICATE: {
650       bssl::UniquePtr<CRYPTO_BUFFER> handle =
651           CreateCertBufferFromBytesWithSanityCheck(data);
652       if (handle)
653         results.push_back(std::move(handle));
654       break;
655     }
656     case FORMAT_PKCS7: {
657       x509_util::CreateCertBuffersFromPKCS7Bytes(data, &results);
658       break;
659     }
660     default: {
661       NOTREACHED() << "Certificate format " << format << " unimplemented";
662       break;
663     }
664   }
665 
666   return results;
667 }
668 
669 // static
CalculateFingerprint256(const CRYPTO_BUFFER * cert)670 SHA256HashValue X509Certificate::CalculateFingerprint256(
671     const CRYPTO_BUFFER* cert) {
672   SHA256HashValue sha256;
673 
674   SHA256(CRYPTO_BUFFER_data(cert), CRYPTO_BUFFER_len(cert), sha256.data);
675   return sha256;
676 }
677 
CalculateChainFingerprint256() const678 SHA256HashValue X509Certificate::CalculateChainFingerprint256() const {
679   SHA256HashValue sha256;
680   memset(sha256.data, 0, sizeof(sha256.data));
681 
682   SHA256_CTX sha256_ctx;
683   SHA256_Init(&sha256_ctx);
684   SHA256_Update(&sha256_ctx, CRYPTO_BUFFER_data(cert_buffer_.get()),
685                 CRYPTO_BUFFER_len(cert_buffer_.get()));
686   for (const auto& cert : intermediate_ca_certs_) {
687     SHA256_Update(&sha256_ctx, CRYPTO_BUFFER_data(cert.get()),
688                   CRYPTO_BUFFER_len(cert.get()));
689   }
690   SHA256_Final(sha256.data, &sha256_ctx);
691 
692   return sha256;
693 }
694 
695 // static
IsSelfSigned(CRYPTO_BUFFER * cert_buffer)696 bool X509Certificate::IsSelfSigned(CRYPTO_BUFFER* cert_buffer) {
697   std::shared_ptr<const ParsedCertificate> parsed_cert =
698       ParsedCertificate::Create(bssl::UpRef(cert_buffer),
699                                 x509_util::DefaultParseCertificateOptions(),
700                                 /*errors=*/nullptr);
701   if (!parsed_cert) {
702     return false;
703   }
704   return VerifyCertificateIsSelfSigned(*parsed_cert, /*cache=*/nullptr,
705                                        /*errors=*/nullptr);
706 }
707 
X509Certificate(bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates)708 X509Certificate::X509Certificate(
709     bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,
710     std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates)
711     : X509Certificate(std::move(cert_buffer), std::move(intermediates), {}) {}
712 
X509Certificate(bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates,UnsafeCreateOptions options)713 X509Certificate::X509Certificate(
714     bssl::UniquePtr<CRYPTO_BUFFER> cert_buffer,
715     std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates,
716     UnsafeCreateOptions options)
717     : cert_buffer_(std::move(cert_buffer)),
718       intermediate_ca_certs_(std::move(intermediates)) {
719   // Platform-specific initialization.
720   if (!Initialize(options) && cert_buffer_) {
721     // Signal initialization failure by clearing cert_buffer_.
722     cert_buffer_.reset();
723   }
724 }
725 
726 X509Certificate::~X509Certificate() = default;
727 
Initialize(UnsafeCreateOptions options)728 bool X509Certificate::Initialize(UnsafeCreateOptions options) {
729   der::Input tbs_certificate_tlv;
730   der::Input signature_algorithm_tlv;
731   der::BitString signature_value;
732 
733   if (!ParseCertificate(der::Input(CRYPTO_BUFFER_data(cert_buffer_.get()),
734                                    CRYPTO_BUFFER_len(cert_buffer_.get())),
735                         &tbs_certificate_tlv, &signature_algorithm_tlv,
736                         &signature_value, nullptr)) {
737     return false;
738   }
739 
740   ParsedTbsCertificate tbs;
741   if (!ParseTbsCertificate(tbs_certificate_tlv,
742                            x509_util::DefaultParseCertificateOptions(), &tbs,
743                            nullptr))
744     return false;
745 
746   CertPrincipal::PrintableStringHandling printable_string_handling =
747       options.printable_string_is_utf8
748           ? CertPrincipal::PrintableStringHandling::kAsUTF8Hack
749           : CertPrincipal::PrintableStringHandling::kDefault;
750   if (!subject_.ParseDistinguishedName(tbs.subject_tlv,
751                                        printable_string_handling) ||
752       !issuer_.ParseDistinguishedName(tbs.issuer_tlv,
753                                       printable_string_handling)) {
754     return false;
755   }
756 
757   if (!der::GeneralizedTimeToTime(tbs.validity_not_before, &valid_start_) ||
758       !der::GeneralizedTimeToTime(tbs.validity_not_after, &valid_expiry_)) {
759     return false;
760   }
761   serial_number_ = tbs.serial_number.AsString();
762   return true;
763 }
764 
765 }  // namespace net
766