quic/core/crypto/certificate_view.cc - quiche - Git at Google

 // Copyright 2020 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "net/third_party/quiche/src/quic/core/crypto/certificate_view.h"

 #include <algorithm>
 #include <cstdint>
 #include <memory>
 #include <string>

 #include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
 #include "third_party/boringssl/src/include/openssl/base.h"
 #include "third_party/boringssl/src/include/openssl/bytestring.h"
 #include "third_party/boringssl/src/include/openssl/digest.h"
 #include "third_party/boringssl/src/include/openssl/ec.h"
 #include "third_party/boringssl/src/include/openssl/ec_key.h"
 #include "third_party/boringssl/src/include/openssl/evp.h"
 #include "third_party/boringssl/src/include/openssl/nid.h"
 #include "third_party/boringssl/src/include/openssl/rsa.h"
 #include "third_party/boringssl/src/include/openssl/ssl.h"
 #include "net/third_party/quiche/src/quic/core/crypto/boring_utils.h"
 #include "net/third_party/quiche/src/quic/core/quic_time.h"
 #include "net/third_party/quiche/src/quic/core/quic_types.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_ip_address.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
 #include "net/third_party/quiche/src/common/platform/api/quiche_str_cat.h"
 #include "net/third_party/quiche/src/common/platform/api/quiche_text_utils.h"
 #include "net/third_party/quiche/src/common/platform/api/quiche_time_utils.h"
 #include "net/third_party/quiche/src/common/quiche_data_reader.h"

 namespace {

 using ::quiche::QuicheTextUtils;

 // The literals below were encoded using `ascii2der | xxd -i`.  The comments
 // above the literals are the contents in the der2ascii syntax.

 // X.509 version 3 (version numbering starts with zero).
 // INTEGER { 2 }
 constexpr uint8_t kX509Version[] = {0x02, 0x01, 0x02};

 // 2.5.29.17
 constexpr uint8_t kSubjectAltNameOid[] = {0x55, 0x1d, 0x11};

 enum class PublicKeyType {
   kRsa,
   kP256,
   kP384,
   kEd25519,
   kUnknown,
 };

 PublicKeyType PublicKeyTypeFromKey(EVP_PKEY* public_key) {
   switch (EVP_PKEY_id(public_key)) {
     case EVP_PKEY_RSA:
       return PublicKeyType::kRsa;
     case EVP_PKEY_EC: {
       const EC_KEY* key = EVP_PKEY_get0_EC_KEY(public_key);
       if (key == nullptr) {
         return PublicKeyType::kUnknown;
       }
       const EC_GROUP* group = EC_KEY_get0_group(key);
       if (group == nullptr) {
         return PublicKeyType::kUnknown;
       }
       const int curve_nid = EC_GROUP_get_curve_name(group);
       switch (curve_nid) {
         case NID_X9_62_prime256v1:
           return PublicKeyType::kP256;
         case NID_secp384r1:
           return PublicKeyType::kP384;
         default:
           return PublicKeyType::kUnknown;
       }
     }
     case EVP_PKEY_ED25519:
       return PublicKeyType::kEd25519;
     default:
       return PublicKeyType::kUnknown;
   }
 }

 PublicKeyType PublicKeyTypeFromSignatureAlgorithm(
     uint16_t signature_algorithm) {
   switch (signature_algorithm) {
     case SSL_SIGN_RSA_PSS_RSAE_SHA256:
       return PublicKeyType::kRsa;
     case SSL_SIGN_ECDSA_SECP256R1_SHA256:
       return PublicKeyType::kP256;
     case SSL_SIGN_ECDSA_SECP384R1_SHA384:
       return PublicKeyType::kP384;
     case SSL_SIGN_ED25519:
       return PublicKeyType::kEd25519;
     default:
       return PublicKeyType::kUnknown;
   }
 }

 }  // namespace

 namespace quic {

 absl::optional<quic::QuicWallTime> ParseDerTime(unsigned tag,
                                                 absl::string_view payload) {
   if (tag != CBS_ASN1_GENERALIZEDTIME && tag != CBS_ASN1_UTCTIME) {
     QUIC_BUG << "Invalid tag supplied for a DER timestamp";
     return absl::nullopt;
   }

   const size_t year_length = tag == CBS_ASN1_GENERALIZEDTIME ? 4 : 2;
   uint64_t year, month, day, hour, minute, second;
   quiche::QuicheDataReader reader(payload);
   if (!reader.ReadDecimal64(year_length, &year) ||
       !reader.ReadDecimal64(2, &month) || !reader.ReadDecimal64(2, &day) ||
       !reader.ReadDecimal64(2, &hour) || !reader.ReadDecimal64(2, &minute) ||
       !reader.ReadDecimal64(2, &second) ||
       reader.ReadRemainingPayload() != "Z") {
     QUIC_DLOG(WARNING) << "Failed to parse the DER timestamp";
     return absl::nullopt;
   }

   if (tag == CBS_ASN1_UTCTIME) {
     DCHECK_LE(year, 100u);
     year += (year >= 50) ? 1900 : 2000;
   }

   const absl::optional<int64_t> unix_time =
       quiche::QuicheUtcDateTimeToUnixSeconds(year, month, day, hour, minute,
                                              second);
   if (!unix_time.has_value() || *unix_time < 0) {
     return absl::nullopt;
   }
   return QuicWallTime::FromUNIXSeconds(*unix_time);
 }

 PemReadResult ReadNextPemMessage(std::istream* input) {
   constexpr absl::string_view kPemBegin = "-----BEGIN ";
   constexpr absl::string_view kPemEnd = "-----END ";
   constexpr absl::string_view kPemDashes = "-----";

   std::string line_buffer, encoded_message_contents, expected_end;
   bool pending_message = false;
   PemReadResult result;
   while (std::getline(*input, line_buffer)) {
     absl::string_view line(line_buffer);
     QuicheTextUtils::RemoveLeadingAndTrailingWhitespace(&line);

     // Handle BEGIN lines.
     if (!pending_message && QuicheTextUtils::StartsWith(line, kPemBegin) &&
         QuicheTextUtils::EndsWith(line, kPemDashes)) {
       result.type = std::string(
           line.substr(kPemBegin.size(),
                       line.size() - kPemDashes.size() - kPemBegin.size()));
       expected_end = quiche::QuicheStrCat(kPemEnd, result.type, kPemDashes);
       pending_message = true;
       continue;
     }

     // Handle END lines.
     if (pending_message && line == expected_end) {
       absl::optional<std::string> data =
           QuicheTextUtils::Base64Decode(encoded_message_contents);
       if (data.has_value()) {
         result.status = PemReadResult::kOk;
         result.contents = data.value();
       } else {
         result.status = PemReadResult::kError;
       }
       return result;
     }

     if (pending_message) {
       encoded_message_contents.append(std::string(line));
     }
   }
   bool eof_reached = input->eof() && !pending_message;
   return PemReadResult{
       (eof_reached ? PemReadResult::kEof : PemReadResult::kError), "", ""};
 }

 std::unique_ptr<CertificateView> CertificateView::ParseSingleCertificate(
     absl::string_view certificate) {
   std::unique_ptr<CertificateView> result(new CertificateView());
   CBS top = StringPieceToCbs(certificate);

   CBS top_certificate, tbs_certificate, signature_algorithm, signature;
   if (!CBS_get_asn1(&top, &top_certificate, CBS_ASN1_SEQUENCE) ||
       CBS_len(&top) != 0) {
     return nullptr;
   }

   // Certificate  ::=  SEQUENCE  {
   if (
       //   tbsCertificate       TBSCertificate,
       !CBS_get_asn1(&top_certificate, &tbs_certificate, CBS_ASN1_SEQUENCE) ||

       //   signatureAlgorithm   AlgorithmIdentifier,
       !CBS_get_asn1(&top_certificate, &signature_algorithm,
                     CBS_ASN1_SEQUENCE) ||

       //   signature            BIT STRING  }
       !CBS_get_asn1(&top_certificate, &signature, CBS_ASN1_BITSTRING) ||
       CBS_len(&top_certificate) != 0) {
     return nullptr;
   }

   int has_version, has_extensions;
   CBS version, serial, signature_algorithm_inner, issuer, validity, subject,
       spki, issuer_id, subject_id, extensions_outer;
   // TBSCertificate  ::=  SEQUENCE  {
   if (
       //   version         [0]  Version DEFAULT v1,
       !CBS_get_optional_asn1(
           &tbs_certificate, &version, &has_version,
           CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||

       //   serialNumber         CertificateSerialNumber,
       !CBS_get_asn1(&tbs_certificate, &serial, CBS_ASN1_INTEGER) ||

       //   signature            AlgorithmIdentifier,
       !CBS_get_asn1(&tbs_certificate, &signature_algorithm_inner,
                     CBS_ASN1_SEQUENCE) ||

       //   issuer               Name,
       !CBS_get_asn1(&tbs_certificate, &issuer, CBS_ASN1_SEQUENCE) ||

       //   validity             Validity,
       !CBS_get_asn1(&tbs_certificate, &validity, CBS_ASN1_SEQUENCE) ||

       //   subject              Name,
       !CBS_get_asn1(&tbs_certificate, &subject, CBS_ASN1_SEQUENCE) ||

       //   subjectPublicKeyInfo SubjectPublicKeyInfo,
       !CBS_get_asn1_element(&tbs_certificate, &spki, CBS_ASN1_SEQUENCE) ||

       //   issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
       //                        -- If present, version MUST be v2 or v3
       !CBS_get_optional_asn1(&tbs_certificate, &issuer_id, nullptr,
                              CBS_ASN1_CONTEXT_SPECIFIC | 1) ||

       //   subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL,
       //                        -- If present, version MUST be v2 or v3
       !CBS_get_optional_asn1(&tbs_certificate, &subject_id, nullptr,
                              CBS_ASN1_CONTEXT_SPECIFIC | 2) ||

       //   extensions      [3]  Extensions OPTIONAL
       //                        -- If present, version MUST be v3 --  }
       !CBS_get_optional_asn1(
           &tbs_certificate, &extensions_outer, &has_extensions,
           CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 3) ||

       CBS_len(&tbs_certificate) != 0) {
     return nullptr;
   }

   unsigned not_before_tag, not_after_tag;
   CBS not_before, not_after;
   if (!CBS_get_any_asn1(&validity, &not_before, &not_before_tag) ||
       !CBS_get_any_asn1(&validity, &not_after, &not_after_tag) ||
       CBS_len(&validity) != 0) {
     QUIC_DLOG(WARNING) << "Failed to extract the validity dates";
     return nullptr;
   }
   absl::optional<QuicWallTime> not_before_parsed =
       ParseDerTime(not_before_tag, CbsToStringPiece(not_before));
   absl::optional<QuicWallTime> not_after_parsed =
       ParseDerTime(not_after_tag, CbsToStringPiece(not_after));
   if (!not_before_parsed.has_value() || !not_after_parsed.has_value()) {
     QUIC_DLOG(WARNING) << "Failed to parse validity dates";
     return nullptr;
   }
   result->validity_start_ = *not_before_parsed;
   result->validity_end_ = *not_after_parsed;

   result->public_key_.reset(EVP_parse_public_key(&spki));
   if (result->public_key_ == nullptr) {
     QUIC_DLOG(WARNING) << "Failed to parse the public key";
     return nullptr;
   }
   if (!result->ValidatePublicKeyParameters()) {
     QUIC_DLOG(WARNING) << "Public key has invalid parameters";
     return nullptr;
   }

   // Only support X.509v3.
   if (!has_version ||
       !CBS_mem_equal(&version, kX509Version, sizeof(kX509Version))) {
     QUIC_DLOG(WARNING) << "Bad X.509 version";
     return nullptr;
   }

   if (!has_extensions) {
     return nullptr;
   }

   CBS extensions;
   if (!CBS_get_asn1(&extensions_outer, &extensions, CBS_ASN1_SEQUENCE) ||
       CBS_len(&extensions_outer) != 0) {
     QUIC_DLOG(WARNING) << "Failed to extract the extension sequence";
     return nullptr;
   }
   if (!result->ParseExtensions(extensions)) {
     QUIC_DLOG(WARNING) << "Failed to parse extensions";
     return nullptr;
   }

   return result;
 }

 bool CertificateView::ParseExtensions(CBS extensions) {
   while (CBS_len(&extensions) != 0) {
     CBS extension, oid, critical, payload;
     if (
         // Extension  ::=  SEQUENCE  {
         !CBS_get_asn1(&extensions, &extension, CBS_ASN1_SEQUENCE) ||
         //     extnID      OBJECT IDENTIFIER,
         !CBS_get_asn1(&extension, &oid, CBS_ASN1_OBJECT) ||
         //     critical    BOOLEAN DEFAULT FALSE,
         !CBS_get_optional_asn1(&extension, &critical, nullptr,
                                CBS_ASN1_BOOLEAN) ||
         //     extnValue   OCTET STRING
         //                 -- contains the DER encoding of an ASN.1 value
         //                 -- corresponding to the extension type identified
         //                 -- by extnID
         !CBS_get_asn1(&extension, &payload, CBS_ASN1_OCTETSTRING) ||
         CBS_len(&extension) != 0) {
       QUIC_DLOG(WARNING) << "Bad extension entry";
       return false;
     }

     if (CBS_mem_equal(&oid, kSubjectAltNameOid, sizeof(kSubjectAltNameOid))) {
       CBS alt_names;
       if (!CBS_get_asn1(&payload, &alt_names, CBS_ASN1_SEQUENCE) ||
           CBS_len(&payload) != 0) {
         QUIC_DLOG(WARNING) << "Failed to parse subjectAltName";
         return false;
       }
       while (CBS_len(&alt_names) != 0) {
         CBS alt_name_cbs;
         unsigned int alt_name_tag;
         if (!CBS_get_any_asn1(&alt_names, &alt_name_cbs, &alt_name_tag)) {
           QUIC_DLOG(WARNING) << "Failed to parse subjectAltName";
           return false;
         }

         absl::string_view alt_name = CbsToStringPiece(alt_name_cbs);
         QuicIpAddress ip_address;
         // GeneralName ::= CHOICE {
         switch (alt_name_tag) {
           // dNSName                   [2]  IA5String,
           case CBS_ASN1_CONTEXT_SPECIFIC | 2:
             subject_alt_name_domains_.push_back(alt_name);
             break;

           // iPAddress                 [7]  OCTET STRING,
           case CBS_ASN1_CONTEXT_SPECIFIC | 7:
             if (!ip_address.FromPackedString(alt_name.data(),
                                              alt_name.size())) {
               QUIC_DLOG(WARNING) << "Failed to parse subjectAltName IP address";
               return false;
             }
             subject_alt_name_ips_.push_back(ip_address);
             break;

           default:
             QUIC_DLOG(INFO) << "Unknown subjectAltName tag " << alt_name_tag;
             continue;
         }
       }
     }
   }

   return true;
 }

 std::vector<std::string> CertificateView::LoadPemFromStream(
     std::istream* input) {
   std::vector<std::string> result;
   for (;;) {
     PemReadResult read_result = ReadNextPemMessage(input);
     if (read_result.status == PemReadResult::kEof) {
       return result;
     }
     if (read_result.status != PemReadResult::kOk) {
       return std::vector<std::string>();
     }
     if (read_result.type != "CERTIFICATE") {
       continue;
     }
     result.emplace_back(std::move(read_result.contents));
   }
 }

 bool CertificateView::ValidatePublicKeyParameters() {
   // The profile here affects what certificates can be used:
   // (1) when QUIC is used as a server library without any custom certificate
   //     provider logic,
   // (2) when QuicTransport is handling self-signed certificates.
   // The goal is to allow at minimum any certificate that would be allowed on a
   // regular Web session over TLS 1.3 while ensuring we do not expose any
   // algorithms we don't want to support long-term.
   PublicKeyType key_type = PublicKeyTypeFromKey(public_key_.get());
   switch (key_type) {
     case PublicKeyType::kRsa:
       return EVP_PKEY_bits(public_key_.get()) >= 2048;
     case PublicKeyType::kP256:
     case PublicKeyType::kP384:
     case PublicKeyType::kEd25519:
       return true;
     default:
       return false;
   }
 }

 bool CertificateView::VerifySignature(absl::string_view data,
                                       absl::string_view signature,
                                       uint16_t signature_algorithm) const {
   if (PublicKeyTypeFromSignatureAlgorithm(signature_algorithm) !=
       PublicKeyTypeFromKey(public_key_.get())) {
     QUIC_BUG << "Mismatch between the requested signature algorithm and the "
                 "type of the public key.";
     return false;
   }

   bssl::ScopedEVP_MD_CTX md_ctx;
   EVP_PKEY_CTX* pctx;
   if (!EVP_DigestVerifyInit(
           md_ctx.get(), &pctx,
           SSL_get_signature_algorithm_digest(signature_algorithm), nullptr,
           public_key_.get())) {
     return false;
   }
   if (SSL_is_signature_algorithm_rsa_pss(signature_algorithm)) {
     if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) ||
         !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1)) {
       return false;
     }
   }
   return EVP_DigestVerify(
       md_ctx.get(), reinterpret_cast<const uint8_t*>(signature.data()),
       signature.size(), reinterpret_cast<const uint8_t*>(data.data()),
       data.size());
 }

 std::unique_ptr<CertificatePrivateKey> CertificatePrivateKey::LoadFromDer(
     absl::string_view private_key) {
   std::unique_ptr<CertificatePrivateKey> result(new CertificatePrivateKey());
   CBS private_key_cbs = StringPieceToCbs(private_key);
   result->private_key_.reset(EVP_parse_private_key(&private_key_cbs));
   if (result->private_key_ == nullptr || CBS_len(&private_key_cbs) != 0) {
     return nullptr;
   }
   return result;
 }

 std::unique_ptr<CertificatePrivateKey> CertificatePrivateKey::LoadPemFromStream(
     std::istream* input) {
 skip:
   PemReadResult result = ReadNextPemMessage(input);
   if (result.status != PemReadResult::kOk) {
     return nullptr;
   }
   // RFC 5958 OneAsymmetricKey message.
   if (result.type == "PRIVATE KEY") {
     return LoadFromDer(result.contents);
   }
   // Legacy OpenSSL format: PKCS#1 (RFC 8017) RSAPrivateKey message.
   if (result.type == "RSA PRIVATE KEY") {
     CBS private_key_cbs = StringPieceToCbs(result.contents);
     bssl::UniquePtr<RSA> rsa(RSA_parse_private_key(&private_key_cbs));
     if (rsa == nullptr || CBS_len(&private_key_cbs) != 0) {
       return nullptr;
     }

     std::unique_ptr<CertificatePrivateKey> key(new CertificatePrivateKey());
     key->private_key_.reset(EVP_PKEY_new());
     EVP_PKEY_assign_RSA(key->private_key_.get(), rsa.release());
     return key;
   }
   // EC keys are sometimes generated with "openssl ecparam -genkey". If the user
   // forgets -noout, OpenSSL will output a redundant copy of the EC parameters.
   // Skip those.
   if (result.type == "EC PARAMETERS") {
     goto skip;
   }
   // Legacy OpenSSL format: RFC 5915 ECPrivateKey message.
   if (result.type == "EC PRIVATE KEY") {
     CBS private_key_cbs = StringPieceToCbs(result.contents);
     bssl::UniquePtr<EC_KEY> ec_key(
         EC_KEY_parse_private_key(&private_key_cbs, /*group=*/nullptr));
     if (ec_key == nullptr || CBS_len(&private_key_cbs) != 0) {
       return nullptr;
     }

     std::unique_ptr<CertificatePrivateKey> key(new CertificatePrivateKey());
     key->private_key_.reset(EVP_PKEY_new());
     EVP_PKEY_assign_EC_KEY(key->private_key_.get(), ec_key.release());
     return key;
   }
   // Unknown format.
   return nullptr;
 }

 std::string CertificatePrivateKey::Sign(absl::string_view input,
                                         uint16_t signature_algorithm) {
   if (!ValidForSignatureAlgorithm(signature_algorithm)) {
     QUIC_BUG << "Mismatch between the requested signature algorithm and the "
                 "type of the private key.";
     return "";
   }

   bssl::ScopedEVP_MD_CTX md_ctx;
   EVP_PKEY_CTX* pctx;
   if (!EVP_DigestSignInit(
           md_ctx.get(), &pctx,
           SSL_get_signature_algorithm_digest(signature_algorithm),
           /*e=*/nullptr, private_key_.get())) {
     return "";
   }
   if (SSL_is_signature_algorithm_rsa_pss(signature_algorithm)) {
     if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) ||
         !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1)) {
       return "";
     }
   }

   std::string output;
   size_t output_size;
   if (!EVP_DigestSign(md_ctx.get(), /*out_sig=*/nullptr, &output_size,
                       reinterpret_cast<const uint8_t*>(input.data()),
                       input.size())) {
     return "";
   }
   output.resize(output_size);
   if (!EVP_DigestSign(
           md_ctx.get(), reinterpret_cast<uint8_t*>(&output[0]), &output_size,
           reinterpret_cast<const uint8_t*>(input.data()), input.size())) {
     return "";
   }
   output.resize(output_size);
   return output;
 }

 bool CertificatePrivateKey::MatchesPublicKey(const CertificateView& view) {
   return EVP_PKEY_cmp(view.public_key(), private_key_.get()) == 1;
 }

 bool CertificatePrivateKey::ValidForSignatureAlgorithm(
     uint16_t signature_algorithm) {
   return PublicKeyTypeFromSignatureAlgorithm(signature_algorithm) ==
          PublicKeyTypeFromKey(private_key_.get());
 }

 }  // namespace quic
	// Copyright 2020 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "net/third_party/quiche/src/quic/core/crypto/certificate_view.h"

	#include <algorithm>
	#include <cstdint>
	#include <memory>
	#include <string>

	#include "absl/strings/string_view.h"
	#include "absl/types/optional.h"
	#include "third_party/boringssl/src/include/openssl/base.h"
	#include "third_party/boringssl/src/include/openssl/bytestring.h"
	#include "third_party/boringssl/src/include/openssl/digest.h"
	#include "third_party/boringssl/src/include/openssl/ec.h"
	#include "third_party/boringssl/src/include/openssl/ec_key.h"
	#include "third_party/boringssl/src/include/openssl/evp.h"
	#include "third_party/boringssl/src/include/openssl/nid.h"
	#include "third_party/boringssl/src/include/openssl/rsa.h"
	#include "third_party/boringssl/src/include/openssl/ssl.h"
	#include "net/third_party/quiche/src/quic/core/crypto/boring_utils.h"
	#include "net/third_party/quiche/src/quic/core/quic_time.h"
	#include "net/third_party/quiche/src/quic/core/quic_types.h"
	#include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
	#include "net/third_party/quiche/src/quic/platform/api/quic_ip_address.h"
	#include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
	#include "net/third_party/quiche/src/common/platform/api/quiche_str_cat.h"
	#include "net/third_party/quiche/src/common/platform/api/quiche_text_utils.h"
	#include "net/third_party/quiche/src/common/platform/api/quiche_time_utils.h"
	#include "net/third_party/quiche/src/common/quiche_data_reader.h"

	namespace {

	using ::quiche::QuicheTextUtils;

	// The literals below were encoded using `ascii2der \| xxd -i`. The comments
	// above the literals are the contents in the der2ascii syntax.

	// X.509 version 3 (version numbering starts with zero).
	// INTEGER { 2 }
	constexpr uint8_t kX509Version[] = {0x02, 0x01, 0x02};

	// 2.5.29.17
	constexpr uint8_t kSubjectAltNameOid[] = {0x55, 0x1d, 0x11};

	enum class PublicKeyType {
	kRsa,
	kP256,
	kP384,
	kEd25519,
	kUnknown,
	};

	PublicKeyType PublicKeyTypeFromKey(EVP_PKEY* public_key) {
	switch (EVP_PKEY_id(public_key)) {
	case EVP_PKEY_RSA:
	return PublicKeyType::kRsa;
	case EVP_PKEY_EC: {
	const EC_KEY* key = EVP_PKEY_get0_EC_KEY(public_key);
	if (key == nullptr) {
	return PublicKeyType::kUnknown;
	}
	const EC_GROUP* group = EC_KEY_get0_group(key);
	if (group == nullptr) {
	return PublicKeyType::kUnknown;
	}
	const int curve_nid = EC_GROUP_get_curve_name(group);
	switch (curve_nid) {
	case NID_X9_62_prime256v1:
	return PublicKeyType::kP256;
	case NID_secp384r1:
	return PublicKeyType::kP384;
	default:
	return PublicKeyType::kUnknown;
	}
	}
	case EVP_PKEY_ED25519:
	return PublicKeyType::kEd25519;
	default:
	return PublicKeyType::kUnknown;
	}
	}

	PublicKeyType PublicKeyTypeFromSignatureAlgorithm(
	uint16_t signature_algorithm) {
	switch (signature_algorithm) {
	case SSL_SIGN_RSA_PSS_RSAE_SHA256:
	return PublicKeyType::kRsa;
	case SSL_SIGN_ECDSA_SECP256R1_SHA256:
	return PublicKeyType::kP256;
	case SSL_SIGN_ECDSA_SECP384R1_SHA384:
	return PublicKeyType::kP384;
	case SSL_SIGN_ED25519:
	return PublicKeyType::kEd25519;
	default:
	return PublicKeyType::kUnknown;
	}
	}

	} // namespace

	namespace quic {

	absl::optional<quic::QuicWallTime> ParseDerTime(unsigned tag,
	absl::string_view payload) {
	if (tag != CBS_ASN1_GENERALIZEDTIME && tag != CBS_ASN1_UTCTIME) {
	QUIC_BUG << "Invalid tag supplied for a DER timestamp";
	return absl::nullopt;
	}

	const size_t year_length = tag == CBS_ASN1_GENERALIZEDTIME ? 4 : 2;
	uint64_t year, month, day, hour, minute, second;
	quiche::QuicheDataReader reader(payload);
	if (!reader.ReadDecimal64(year_length, &year) \|\|
	!reader.ReadDecimal64(2, &month) \|\| !reader.ReadDecimal64(2, &day) \|\|
	!reader.ReadDecimal64(2, &hour) \|\| !reader.ReadDecimal64(2, &minute) \|\|
	!reader.ReadDecimal64(2, &second) \|\|
	reader.ReadRemainingPayload() != "Z") {
	QUIC_DLOG(WARNING) << "Failed to parse the DER timestamp";
	return absl::nullopt;
	}

	if (tag == CBS_ASN1_UTCTIME) {
	DCHECK_LE(year, 100u);
	year += (year >= 50) ? 1900 : 2000;
	}

	const absl::optional<int64_t> unix_time =
	quiche::QuicheUtcDateTimeToUnixSeconds(year, month, day, hour, minute,
	second);
	if (!unix_time.has_value() \|\| *unix_time < 0) {
	return absl::nullopt;
	}
	return QuicWallTime::FromUNIXSeconds(*unix_time);
	}

	PemReadResult ReadNextPemMessage(std::istream* input) {
	constexpr absl::string_view kPemBegin = "-----BEGIN ";
	constexpr absl::string_view kPemEnd = "-----END ";
	constexpr absl::string_view kPemDashes = "-----";

	std::string line_buffer, encoded_message_contents, expected_end;
	bool pending_message = false;
	PemReadResult result;
	while (std::getline(*input, line_buffer)) {
	absl::string_view line(line_buffer);
	QuicheTextUtils::RemoveLeadingAndTrailingWhitespace(&line);

	// Handle BEGIN lines.
	if (!pending_message && QuicheTextUtils::StartsWith(line, kPemBegin) &&
	QuicheTextUtils::EndsWith(line, kPemDashes)) {
	result.type = std::string(
	line.substr(kPemBegin.size(),
	line.size() - kPemDashes.size() - kPemBegin.size()));
	expected_end = quiche::QuicheStrCat(kPemEnd, result.type, kPemDashes);
	pending_message = true;
	continue;
	}

	// Handle END lines.
	if (pending_message && line == expected_end) {
	absl::optional<std::string> data =
	QuicheTextUtils::Base64Decode(encoded_message_contents);
	if (data.has_value()) {
	result.status = PemReadResult::kOk;
	result.contents = data.value();
	} else {
	result.status = PemReadResult::kError;
	}
	return result;
	}

	if (pending_message) {
	encoded_message_contents.append(std::string(line));
	}
	}
	bool eof_reached = input->eof() && !pending_message;
	return PemReadResult{
	(eof_reached ? PemReadResult::kEof : PemReadResult::kError), "", ""};
	}

	std::unique_ptr<CertificateView> CertificateView::ParseSingleCertificate(
	absl::string_view certificate) {
	std::unique_ptr<CertificateView> result(new CertificateView());
	CBS top = StringPieceToCbs(certificate);

	CBS top_certificate, tbs_certificate, signature_algorithm, signature;
	if (!CBS_get_asn1(&top, &top_certificate, CBS_ASN1_SEQUENCE) \|\|
	CBS_len(&top) != 0) {
	return nullptr;
	}

	// Certificate ::= SEQUENCE {
	if (
	// tbsCertificate TBSCertificate,
	!CBS_get_asn1(&top_certificate, &tbs_certificate, CBS_ASN1_SEQUENCE) \|\|

	// signatureAlgorithm AlgorithmIdentifier,
	!CBS_get_asn1(&top_certificate, &signature_algorithm,
	CBS_ASN1_SEQUENCE) \|\|

	// signature BIT STRING }
	!CBS_get_asn1(&top_certificate, &signature, CBS_ASN1_BITSTRING) \|\|
	CBS_len(&top_certificate) != 0) {
	return nullptr;
	}

	int has_version, has_extensions;
	CBS version, serial, signature_algorithm_inner, issuer, validity, subject,
	spki, issuer_id, subject_id, extensions_outer;
	// TBSCertificate ::= SEQUENCE {
	if (
	// version [0] Version DEFAULT v1,
	!CBS_get_optional_asn1(
	&tbs_certificate, &version, &has_version,
	CBS_ASN1_CONSTRUCTED \| CBS_ASN1_CONTEXT_SPECIFIC \| 0) \|\|

	// serialNumber CertificateSerialNumber,
	!CBS_get_asn1(&tbs_certificate, &serial, CBS_ASN1_INTEGER) \|\|

	// signature AlgorithmIdentifier,
	!CBS_get_asn1(&tbs_certificate, &signature_algorithm_inner,
	CBS_ASN1_SEQUENCE) \|\|

	// issuer Name,
	!CBS_get_asn1(&tbs_certificate, &issuer, CBS_ASN1_SEQUENCE) \|\|

	// validity Validity,
	!CBS_get_asn1(&tbs_certificate, &validity, CBS_ASN1_SEQUENCE) \|\|

	// subject Name,
	!CBS_get_asn1(&tbs_certificate, &subject, CBS_ASN1_SEQUENCE) \|\|

	// subjectPublicKeyInfo SubjectPublicKeyInfo,
	!CBS_get_asn1_element(&tbs_certificate, &spki, CBS_ASN1_SEQUENCE) \|\|

	// issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
	// -- If present, version MUST be v2 or v3
	!CBS_get_optional_asn1(&tbs_certificate, &issuer_id, nullptr,
	CBS_ASN1_CONTEXT_SPECIFIC \| 1) \|\|

	// subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
	// -- If present, version MUST be v2 or v3
	!CBS_get_optional_asn1(&tbs_certificate, &subject_id, nullptr,
	CBS_ASN1_CONTEXT_SPECIFIC \| 2) \|\|

	// extensions [3] Extensions OPTIONAL
	// -- If present, version MUST be v3 -- }
	!CBS_get_optional_asn1(
	&tbs_certificate, &extensions_outer, &has_extensions,
	CBS_ASN1_CONSTRUCTED \| CBS_ASN1_CONTEXT_SPECIFIC \| 3) \|\|

	CBS_len(&tbs_certificate) != 0) {
	return nullptr;
	}

	unsigned not_before_tag, not_after_tag;
	CBS not_before, not_after;
	if (!CBS_get_any_asn1(&validity, &not_before, &not_before_tag) \|\|
	!CBS_get_any_asn1(&validity, &not_after, &not_after_tag) \|\|
	CBS_len(&validity) != 0) {
	QUIC_DLOG(WARNING) << "Failed to extract the validity dates";
	return nullptr;
	}
	absl::optional<QuicWallTime> not_before_parsed =
	ParseDerTime(not_before_tag, CbsToStringPiece(not_before));
	absl::optional<QuicWallTime> not_after_parsed =
	ParseDerTime(not_after_tag, CbsToStringPiece(not_after));
	if (!not_before_parsed.has_value() \|\| !not_after_parsed.has_value()) {
	QUIC_DLOG(WARNING) << "Failed to parse validity dates";
	return nullptr;
	}
	result->validity_start_ = *not_before_parsed;
	result->validity_end_ = *not_after_parsed;

	result->public_key_.reset(EVP_parse_public_key(&spki));
	if (result->public_key_ == nullptr) {
	QUIC_DLOG(WARNING) << "Failed to parse the public key";
	return nullptr;
	}
	if (!result->ValidatePublicKeyParameters()) {
	QUIC_DLOG(WARNING) << "Public key has invalid parameters";
	return nullptr;
	}

	// Only support X.509v3.
	if (!has_version \|\|
	!CBS_mem_equal(&version, kX509Version, sizeof(kX509Version))) {
	QUIC_DLOG(WARNING) << "Bad X.509 version";
	return nullptr;
	}

	if (!has_extensions) {
	return nullptr;
	}

	CBS extensions;
	if (!CBS_get_asn1(&extensions_outer, &extensions, CBS_ASN1_SEQUENCE) \|\|
	CBS_len(&extensions_outer) != 0) {
	QUIC_DLOG(WARNING) << "Failed to extract the extension sequence";
	return nullptr;
	}
	if (!result->ParseExtensions(extensions)) {
	QUIC_DLOG(WARNING) << "Failed to parse extensions";
	return nullptr;
	}

	return result;
	}

	bool CertificateView::ParseExtensions(CBS extensions) {
	while (CBS_len(&extensions) != 0) {
	CBS extension, oid, critical, payload;
	if (
	// Extension ::= SEQUENCE {
	!CBS_get_asn1(&extensions, &extension, CBS_ASN1_SEQUENCE) \|\|
	// extnID OBJECT IDENTIFIER,
	!CBS_get_asn1(&extension, &oid, CBS_ASN1_OBJECT) \|\|
	// critical BOOLEAN DEFAULT FALSE,
	!CBS_get_optional_asn1(&extension, &critical, nullptr,
	CBS_ASN1_BOOLEAN) \|\|
	// extnValue OCTET STRING
	// -- contains the DER encoding of an ASN.1 value
	// -- corresponding to the extension type identified
	// -- by extnID
	!CBS_get_asn1(&extension, &payload, CBS_ASN1_OCTETSTRING) \|\|
	CBS_len(&extension) != 0) {
	QUIC_DLOG(WARNING) << "Bad extension entry";
	return false;
	}

	if (CBS_mem_equal(&oid, kSubjectAltNameOid, sizeof(kSubjectAltNameOid))) {
	CBS alt_names;
	if (!CBS_get_asn1(&payload, &alt_names, CBS_ASN1_SEQUENCE) \|\|
	CBS_len(&payload) != 0) {
	QUIC_DLOG(WARNING) << "Failed to parse subjectAltName";
	return false;
	}
	while (CBS_len(&alt_names) != 0) {
	CBS alt_name_cbs;
	unsigned int alt_name_tag;
	if (!CBS_get_any_asn1(&alt_names, &alt_name_cbs, &alt_name_tag)) {
	QUIC_DLOG(WARNING) << "Failed to parse subjectAltName";
	return false;
	}

	absl::string_view alt_name = CbsToStringPiece(alt_name_cbs);
	QuicIpAddress ip_address;
	// GeneralName ::= CHOICE {
	switch (alt_name_tag) {
	// dNSName [2] IA5String,
	case CBS_ASN1_CONTEXT_SPECIFIC \| 2:
	subject_alt_name_domains_.push_back(alt_name);
	break;

	// iPAddress [7] OCTET STRING,
	case CBS_ASN1_CONTEXT_SPECIFIC \| 7:
	if (!ip_address.FromPackedString(alt_name.data(),
	alt_name.size())) {
	QUIC_DLOG(WARNING) << "Failed to parse subjectAltName IP address";
	return false;
	}
	subject_alt_name_ips_.push_back(ip_address);
	break;

	default:
	QUIC_DLOG(INFO) << "Unknown subjectAltName tag " << alt_name_tag;
	continue;
	}
	}
	}
	}

	return true;
	}

	std::vector<std::string> CertificateView::LoadPemFromStream(
	std::istream* input) {
	std::vector<std::string> result;
	for (;;) {
	PemReadResult read_result = ReadNextPemMessage(input);
	if (read_result.status == PemReadResult::kEof) {
	return result;
	}
	if (read_result.status != PemReadResult::kOk) {
	return std::vector<std::string>();
	}
	if (read_result.type != "CERTIFICATE") {
	continue;
	}
	result.emplace_back(std::move(read_result.contents));
	}
	}

	bool CertificateView::ValidatePublicKeyParameters() {
	// The profile here affects what certificates can be used:
	// (1) when QUIC is used as a server library without any custom certificate
	// provider logic,
	// (2) when QuicTransport is handling self-signed certificates.
	// The goal is to allow at minimum any certificate that would be allowed on a
	// regular Web session over TLS 1.3 while ensuring we do not expose any
	// algorithms we don't want to support long-term.
	PublicKeyType key_type = PublicKeyTypeFromKey(public_key_.get());
	switch (key_type) {
	case PublicKeyType::kRsa:
	return EVP_PKEY_bits(public_key_.get()) >= 2048;
	case PublicKeyType::kP256:
	case PublicKeyType::kP384:
	case PublicKeyType::kEd25519:
	return true;
	default:
	return false;
	}
	}

	bool CertificateView::VerifySignature(absl::string_view data,
	absl::string_view signature,
	uint16_t signature_algorithm) const {
	if (PublicKeyTypeFromSignatureAlgorithm(signature_algorithm) !=
	PublicKeyTypeFromKey(public_key_.get())) {
	QUIC_BUG << "Mismatch between the requested signature algorithm and the "
	"type of the public key.";
	return false;
	}

	bssl::ScopedEVP_MD_CTX md_ctx;
	EVP_PKEY_CTX* pctx;
	if (!EVP_DigestVerifyInit(
	md_ctx.get(), &pctx,
	SSL_get_signature_algorithm_digest(signature_algorithm), nullptr,
	public_key_.get())) {
	return false;
	}
	if (SSL_is_signature_algorithm_rsa_pss(signature_algorithm)) {
	if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) \|\|
	!EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1)) {
	return false;
	}
	}
	return EVP_DigestVerify(
	md_ctx.get(), reinterpret_cast<const uint8_t*>(signature.data()),
	signature.size(), reinterpret_cast<const uint8_t*>(data.data()),
	data.size());
	}

	std::unique_ptr<CertificatePrivateKey> CertificatePrivateKey::LoadFromDer(
	absl::string_view private_key) {
	std::unique_ptr<CertificatePrivateKey> result(new CertificatePrivateKey());
	CBS private_key_cbs = StringPieceToCbs(private_key);
	result->private_key_.reset(EVP_parse_private_key(&private_key_cbs));
	if (result->private_key_ == nullptr \|\| CBS_len(&private_key_cbs) != 0) {
	return nullptr;
	}
	return result;
	}

	std::unique_ptr<CertificatePrivateKey> CertificatePrivateKey::LoadPemFromStream(
	std::istream* input) {
	skip:
	PemReadResult result = ReadNextPemMessage(input);
	if (result.status != PemReadResult::kOk) {
	return nullptr;
	}
	// RFC 5958 OneAsymmetricKey message.
	if (result.type == "PRIVATE KEY") {
	return LoadFromDer(result.contents);
	}
	// Legacy OpenSSL format: PKCS#1 (RFC 8017) RSAPrivateKey message.
	if (result.type == "RSA PRIVATE KEY") {
	CBS private_key_cbs = StringPieceToCbs(result.contents);
	bssl::UniquePtr<RSA> rsa(RSA_parse_private_key(&private_key_cbs));
	if (rsa == nullptr \|\| CBS_len(&private_key_cbs) != 0) {
	return nullptr;
	}

	std::unique_ptr<CertificatePrivateKey> key(new CertificatePrivateKey());
	key->private_key_.reset(EVP_PKEY_new());
	EVP_PKEY_assign_RSA(key->private_key_.get(), rsa.release());
	return key;
	}
	// EC keys are sometimes generated with "openssl ecparam -genkey". If the user
	// forgets -noout, OpenSSL will output a redundant copy of the EC parameters.
	// Skip those.
	if (result.type == "EC PARAMETERS") {
	goto skip;
	}
	// Legacy OpenSSL format: RFC 5915 ECPrivateKey message.
	if (result.type == "EC PRIVATE KEY") {
	CBS private_key_cbs = StringPieceToCbs(result.contents);
	bssl::UniquePtr<EC_KEY> ec_key(
	EC_KEY_parse_private_key(&private_key_cbs, /group=/nullptr));
	if (ec_key == nullptr \|\| CBS_len(&private_key_cbs) != 0) {
	return nullptr;
	}

	std::unique_ptr<CertificatePrivateKey> key(new CertificatePrivateKey());
	key->private_key_.reset(EVP_PKEY_new());
	EVP_PKEY_assign_EC_KEY(key->private_key_.get(), ec_key.release());
	return key;
	}
	// Unknown format.
	return nullptr;
	}

	std::string CertificatePrivateKey::Sign(absl::string_view input,
	uint16_t signature_algorithm) {
	if (!ValidForSignatureAlgorithm(signature_algorithm)) {
	QUIC_BUG << "Mismatch between the requested signature algorithm and the "
	"type of the private key.";
	return "";
	}

	bssl::ScopedEVP_MD_CTX md_ctx;
	EVP_PKEY_CTX* pctx;
	if (!EVP_DigestSignInit(
	md_ctx.get(), &pctx,
	SSL_get_signature_algorithm_digest(signature_algorithm),
	/e=/nullptr, private_key_.get())) {
	return "";
	}
	if (SSL_is_signature_algorithm_rsa_pss(signature_algorithm)) {
	if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) \|\|
	!EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1)) {
	return "";
	}
	}

	std::string output;
	size_t output_size;
	if (!EVP_DigestSign(md_ctx.get(), /out_sig=/nullptr, &output_size,
	reinterpret_cast<const uint8_t*>(input.data()),
	input.size())) {
	return "";
	}
	output.resize(output_size);
	if (!EVP_DigestSign(
	md_ctx.get(), reinterpret_cast<uint8_t*>(&output[0]), &output_size,
	reinterpret_cast<const uint8_t*>(input.data()), input.size())) {
	return "";
	}
	output.resize(output_size);
	return output;
	}

	bool CertificatePrivateKey::MatchesPublicKey(const CertificateView& view) {
	return EVP_PKEY_cmp(view.public_key(), private_key_.get()) == 1;
	}

	bool CertificatePrivateKey::ValidForSignatureAlgorithm(
	uint16_t signature_algorithm) {
	return PublicKeyTypeFromSignatureAlgorithm(signature_algorithm) ==
	PublicKeyTypeFromKey(private_key_.get());
	}

	} // namespace quic