/*
* Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
* Copyright (c) 2023, stelar7 <dudedbz@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Certificate.h"
#include <AK/Debug.h>
#include <AK/IPv4Address.h>
#include <LibCrypto/ASN1/ASN1.h>
#include <LibCrypto/ASN1/DER.h>
#include <LibCrypto/ASN1/PEM.h>
namespace {
static String s_error_string;
}
namespace TLS {
#define ERROR_WITH_SCOPE(error) \
do { \
s_error_string = TRY(String::formatted("{}: {}", current_scope, error)); \
return Error::from_string_view(s_error_string.bytes_as_string_view()); \
} while (0)
#define ENTER_TYPED_SCOPE(tag_kind_name, scope) \
do { \
if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::tag_kind_name) { \
if (tag.is_error()) \
ERROR_WITH_SCOPE(TRY(String::formatted(scope " data was invalid: {}", tag.error()))); \
else \
ERROR_WITH_SCOPE(TRY(String::formatted(scope " data was not of kind " #tag_kind_name " was {}", Crypto::ASN1::kind_name(tag.value().kind)))); \
} \
ENTER_SCOPE(scope); \
} while (0)
#define ENTER_SCOPE(scope) \
do { \
if (auto result = decoder.enter(); result.is_error()) { \
ERROR_WITH_SCOPE(TRY(String::formatted("Failed to enter scope: {}", scope))); \
} \
PUSH_SCOPE(scope) \
} while (0)
#define PUSH_SCOPE(scope) current_scope.append(#scope##sv);
#define EXIT_SCOPE() \
do { \
if (auto error = decoder.leave(); error.is_error()) { \
ERROR_WITH_SCOPE(TRY(String::formatted("Failed to exit scope: {}", error.error()))); \
} \
POP_SCOPE(); \
} while (0)
#define POP_SCOPE() current_scope.remove(current_scope.size() - 1);
#define READ_OBJECT(kind_name, type_name, value_name) \
auto value_name##_result = decoder.read<type_name>(Crypto::ASN1::Class::Universal, Crypto::ASN1::Kind::kind_name); \
if (value_name##_result.is_error()) { \
ERROR_WITH_SCOPE(TRY(String::formatted("Read of kind " #kind_name " failed: {}", value_name##_result.error()))); \
} \
auto value_name = value_name##_result.release_value();
#define REWRITE_TAG(kind_name) \
auto value_name##_result = decoder.rewrite_tag(Crypto::ASN1::Kind::kind_name); \
if (value_name##_result.is_error()) { \
ERROR_WITH_SCOPE(TRY(String::formatted("Rewrite of kind " #kind_name " failed: {}", value_name##_result.error()))); \
}
#define DROP_OBJECT() \
do { \
if (auto error = decoder.drop(); error.is_error()) { \
ERROR_WITH_SCOPE(TRY(String::formatted("Drop failed: {}", error.error()))); \
} \
} while (0)
static ErrorOr<SupportedGroup> oid_to_curve(Vector<int> curve)
{
if (curve == curve_ansip384r1)
return SupportedGroup::SECP384R1;
else if (curve == curve_prime256)
return SupportedGroup::SECP256R1;
return Error::from_string_view("Unknown curve oid"sv);
}
static ErrorOr<Crypto::UnsignedBigInteger> parse_certificate_version(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// Version ::= INTEGER {v1(0), v2(1), v3(2)}
if (auto tag = decoder.peek(); !tag.is_error() && tag.value().type == Crypto::ASN1::Type::Constructed) {
ENTER_SCOPE("Version"sv);
READ_OBJECT(Integer, Crypto::UnsignedBigInteger, version);
if (version > 3) {
ERROR_WITH_SCOPE(TRY(String::formatted("Invalid version value at {}", current_scope)));
}
EXIT_SCOPE();
return version;
} else {
return Crypto::UnsignedBigInteger { 0 };
}
}
static ErrorOr<Crypto::UnsignedBigInteger> parse_serial_number(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// CertificateSerialNumber ::= INTEGER
PUSH_SCOPE("CertificateSerialNumber"sv);
READ_OBJECT(Integer, Crypto::UnsignedBigInteger, serial);
POP_SCOPE();
return serial;
}
static ErrorOr<SupportedGroup> parse_ec_parameters(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// ECParameters ::= CHOICE {
// namedCurve OBJECT IDENTIFIER
// }
PUSH_SCOPE("ECParameters"sv);
READ_OBJECT(ObjectIdentifier, Vector<int>, named_curve);
// Note: namedCurve sometimes has 5 nodes, but we need 7 for the comparison below to work.
while (named_curve.size() < 7) {
named_curve.append(0);
}
POP_SCOPE();
bool is_known_curve = false;
for (auto const& curves : known_curve_identifiers) {
if (curves.span() == named_curve.span()) {
is_known_curve = true;
break;
}
}
if (!is_known_curve) {
ERROR_WITH_SCOPE(TRY(String::formatted("Unknown named curve {}", named_curve)));
}
return oid_to_curve(named_curve);
}
static ErrorOr<AlgorithmIdentifier> parse_algorithm_identifier(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// AlgorithmIdentifier{ALGORITHM:SupportedAlgorithms} ::= SEQUENCE {
// algorithm ALGORITHM.&id({SupportedAlgorithms}),
// parameters ALGORITHM.&Type({SupportedAlgorithms}{@algorithm}) OPTIONAL,
// ... }
ENTER_TYPED_SCOPE(Sequence, "AlgorithmIdentifier"sv);
PUSH_SCOPE("algorithm"sv);
READ_OBJECT(ObjectIdentifier, Vector<int>, algorithm);
// Note: ecPublicKey only has 6 nodes, but we need 7 for the comparison below to work.
while (algorithm.size() < 7) {
algorithm.append(0);
}
POP_SCOPE();
bool is_known_algorithm = false;
for (auto const& inner : known_algorithm_identifiers) {
if (inner.span() == algorithm.span()) {
is_known_algorithm = true;
break;
}
}
if (!is_known_algorithm) {
ERROR_WITH_SCOPE(TRY(String::formatted("Unknown algorithm {}", algorithm)));
}
// -- When the following OIDs are used in an AlgorithmIdentifier, the
// -- parameters MUST be present and MUST be NULL.
// sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 1 }
// sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 4 }
// sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 5 }
// sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 11 }
// sha384WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 12 }
// sha512WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 13 }
// sha224WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 14 }
Array<Array<int, 7>, 8> rsa_null_algorithms = {
rsa_encryption_oid,
rsa_md5_encryption_oid,
rsa_sha1_encryption_oid,
rsa_sha256_encryption_oid,
rsa_sha384_encryption_oid,
rsa_sha512_encryption_oid,
rsa_sha224_encryption_oid,
};
bool is_rsa_null_algorithm = false;
for (auto const& inner : rsa_null_algorithms) {
if (inner.span() == algorithm.span()) {
is_rsa_null_algorithm = true;
break;
}
}
if (is_rsa_null_algorithm) {
PUSH_SCOPE("RSA null parameter"sv);
READ_OBJECT(Null, void*, forced_null);
(void)forced_null;
POP_SCOPE();
EXIT_SCOPE();
return AlgorithmIdentifier(algorithm);
}
// When the ecdsa-with-SHA224, ecdsa-with-SHA256, ecdsa-with-SHA384, or
// ecdsa-with-SHA512 algorithm identifier appears in the algorithm field
// as an AlgorithmIdentifier, the encoding MUST omit the parameters
// field.
Array<Array<int, 7>, 8> no_parameter_algorithms = {
ecdsa_with_sha224_encryption_oid,
ecdsa_with_sha256_encryption_oid,
ecdsa_with_sha384_encryption_oid,
ecdsa_with_sha512_encryption_oid,
};
bool is_no_parameter_algorithm = false;
for (auto const& inner : no_parameter_algorithms) {
if (inner.span() == algorithm.span()) {
is_no_parameter_algorithm = true;
}
}
if (is_no_parameter_algorithm) {
EXIT_SCOPE();
return AlgorithmIdentifier(algorithm);
}
if (algorithm.span() == ec_public_key_encryption_oid.span()) {
// The parameters associated with id-ecPublicKey SHOULD be absent or ECParameters,
// and NULL is allowed to support legacy implementations.
if (decoder.eof()) {
EXIT_SCOPE();
return AlgorithmIdentifier(algorithm);
}
auto tag = TRY(decoder.peek());
if (tag.kind == Crypto::ASN1::Kind::Null) {
PUSH_SCOPE("ecPublicKey null parameter"sv);
READ_OBJECT(Null, void*, forced_null);
(void)forced_null;
POP_SCOPE();
EXIT_SCOPE();
return AlgorithmIdentifier(algorithm);
}
auto algorithm_identifier = AlgorithmIdentifier(algorithm);
algorithm_identifier.ec_parameters = TRY(parse_ec_parameters(decoder, current_scope));
EXIT_SCOPE();
return algorithm_identifier;
}
ERROR_WITH_SCOPE(TRY(String::formatted("Unhandled parameters for algorithm {}", algorithm)));
}
static ErrorOr<RelativeDistinguishedName> parse_name(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
RelativeDistinguishedName rdn {};
// Name ::= Choice {
// rdn_sequence RDNSequence
// } // NOTE: since this is the only alternative, there's no index
// RDNSequence ::= Sequence OF RelativeDistinguishedName
ENTER_TYPED_SCOPE(Sequence, "Name"sv);
while (!decoder.eof()) {
// RelativeDistinguishedName ::= Set OF AttributeTypeAndValue
ENTER_TYPED_SCOPE(Set, "RDNSequence"sv);
while (!decoder.eof()) {
// AttributeTypeAndValue ::= Sequence {
// type AttributeType,
// value AttributeValue
// }
ENTER_TYPED_SCOPE(Sequence, "AttributeTypeAndValue"sv);
// AttributeType ::= ObjectIdentifier
PUSH_SCOPE("AttributeType"sv)
READ_OBJECT(ObjectIdentifier, Vector<int>, attribute_type_oid);
POP_SCOPE();
// AttributeValue ::= Any
PUSH_SCOPE("AttributeValue"sv)
READ_OBJECT(PrintableString, StringView, attribute_value);
POP_SCOPE();
auto attribute_type_string = TRY(String::join("."sv, attribute_type_oid));
auto attribute_value_string = TRY(String::from_utf8(attribute_value));
TRY(rdn.set(attribute_type_string, attribute_value_string));
EXIT_SCOPE();
}
EXIT_SCOPE();
}
EXIT_SCOPE();
return rdn;
}
static ErrorOr<Core::DateTime> parse_time(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// Time ::= Choice {
// utc_time UTCTime,
// general_time GeneralizedTime
// }
auto tag = TRY(decoder.peek());
if (tag.kind == Crypto::ASN1::Kind::UTCTime) {
PUSH_SCOPE("UTCTime"sv);
READ_OBJECT(UTCTime, StringView, utc_time);
auto parse_result = Crypto::ASN1::parse_utc_time(utc_time);
if (!parse_result.has_value()) {
ERROR_WITH_SCOPE(TRY(String::formatted("Failed to parse UTCTime {}", utc_time)));
}
POP_SCOPE();
return parse_result.release_value();
}
if (tag.kind == Crypto::ASN1::Kind::GeneralizedTime) {
PUSH_SCOPE("GeneralizedTime"sv);
READ_OBJECT(UTCTime, StringView, generalized_time);
auto parse_result = Crypto::ASN1::parse_generalized_time(generalized_time);
if (!parse_result.has_value()) {
ERROR_WITH_SCOPE(TRY(String::formatted("Failed to parse GeneralizedTime {}", generalized_time)));
}
POP_SCOPE();
return parse_result.release_value();
}
ERROR_WITH_SCOPE(TRY(String::formatted("Unrecognised Time format {}", kind_name(tag.kind))));
}
static ErrorOr<Validity> parse_validity(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
Validity validity {};
// Validity ::= SEQUENCE {
// notBefore Time,
// notAfter Time }
ENTER_TYPED_SCOPE(Sequence, "Validity"sv);
validity.not_before = TRY(parse_time(decoder, current_scope));
validity.not_after = TRY(parse_time(decoder, current_scope));
EXIT_SCOPE();
return validity;
}
static ErrorOr<SubjectPublicKey> parse_subject_public_key_info(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// SubjectPublicKeyInfo ::= Sequence {
// algorithm AlgorithmIdentifier,
// subject_public_key BitString
// }
SubjectPublicKey public_key;
ENTER_TYPED_SCOPE(Sequence, "SubjectPublicKeyInfo"sv);
public_key.algorithm = TRY(parse_algorithm_identifier(decoder, current_scope));
PUSH_SCOPE("subjectPublicKey"sv);
READ_OBJECT(BitString, Crypto::ASN1::BitStringView, value);
POP_SCOPE();
public_key.raw_key = TRY(ByteBuffer::copy(TRY(value.raw_bytes())));
if (public_key.algorithm.identifier.span() == rsa_encryption_oid.span()) {
auto key = Crypto::PK::RSA::parse_rsa_key(TRY(value.raw_bytes()));
if (!key.public_key.length()) {
return Error::from_string_literal("Invalid RSA key");
}
public_key.rsa = move(key.public_key);
EXIT_SCOPE();
return public_key;
}
if (public_key.algorithm.identifier.span() == ec_public_key_encryption_oid.span()) {
// Note: Raw key is already stored, so we can just exit out at this point.
EXIT_SCOPE();
return public_key;
}
String algo_oid = TRY(String::join("."sv, public_key.algorithm.identifier));
ERROR_WITH_SCOPE(TRY(String::formatted("Unhandled algorithm {}", algo_oid)));
EXIT_SCOPE();
return public_key;
}
static ErrorOr<Crypto::ASN1::BitStringView> parse_unique_identifier(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// UniqueIdentifier ::= BIT STRING
PUSH_SCOPE("UniqueIdentifier"sv);
READ_OBJECT(BitString, Crypto::ASN1::BitStringView, value);
POP_SCOPE();
return value;
}
static ErrorOr<String> parse_general_name(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// GeneralName ::= CHOICE {
// otherName [0] INSTANCE OF OTHER-NAME,
// rfc822Name [1] IA5String,
// dNSName [2] IA5String,
// x400Address [3] ORAddress,
// directoryName [4] Name,
// ediPartyName [5] EDIPartyName,
// uniformResourceIdentifier [6] IA5String,
// iPAddress [7] OCTET STRING,
// registeredID [8] OBJECT IDENTIFIER,
// }
auto tag = TRY(decoder.peek());
auto tag_value = static_cast<u8>(tag.kind);
switch (tag_value) {
case 0:
// Note: We don't know how to use this.
PUSH_SCOPE("otherName"sv)
DROP_OBJECT();
POP_SCOPE();
break;
case 1: {
PUSH_SCOPE("rfc822Name"sv)
READ_OBJECT(IA5String, StringView, name);
POP_SCOPE();
return String::from_utf8(name);
}
case 2: {
PUSH_SCOPE("dNSName"sv)
READ_OBJECT(IA5String, StringView, name);
POP_SCOPE();
return String::from_utf8(name);
}
case 3:
// Note: We don't know how to use this.
PUSH_SCOPE("x400Address"sv)
DROP_OBJECT();
POP_SCOPE();
break;
case 4: {
PUSH_SCOPE("directoryName"sv);
READ_OBJECT(OctetString, StringView, directory_name);
Crypto::ASN1::Decoder decoder { directory_name.bytes() };
auto names = TRY(parse_name(decoder, current_scope));
POP_SCOPE();
return names.to_string();
}
case 5:
// Note: We don't know how to use this.
PUSH_SCOPE("ediPartyName");
DROP_OBJECT();
POP_SCOPE();
break;
case 6: {
PUSH_SCOPE("uniformResourceIdentifier"sv);
READ_OBJECT(IA5String, StringView, name);
POP_SCOPE();
return String::from_utf8(name);
}
case 7: {
PUSH_SCOPE("iPAddress"sv);
READ_OBJECT(OctetString, StringView, ip_addr_sv);
IPv4Address ip_addr { ip_addr_sv.bytes().data() };
POP_SCOPE();
return ip_addr.to_string();
}
case 8: {
PUSH_SCOPE("registeredID"sv);
READ_OBJECT(ObjectIdentifier, Vector<int>, identifier);
POP_SCOPE();
return String::join("."sv, identifier);
}
default:
ERROR_WITH_SCOPE("Unknown tag in GeneralNames choice"sv);
}
ERROR_WITH_SCOPE("Unknown tag in GeneralNames choice"sv);
}
static ErrorOr<Vector<String>> parse_general_names(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// GeneralNames ::= Sequence OF GeneralName
ENTER_TYPED_SCOPE(Sequence, "GeneralNames");
Vector<String> names;
while (!decoder.eof()) {
names.append(TRY(parse_general_name(decoder, current_scope)));
}
EXIT_SCOPE();
return names;
}
static ErrorOr<Vector<String>> parse_subject_alternative_names(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// SubjectAlternativeName ::= GeneralNames
PUSH_SCOPE("SubjectAlternativeName"sv);
auto values = TRY(parse_general_names(decoder, current_scope));
POP_SCOPE();
return values;
}
static ErrorOr<Vector<String>> parse_issuer_alternative_names(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// issuerAltName ::= GeneralNames
PUSH_SCOPE("issuerAltName"sv);
auto values = TRY(parse_general_names(decoder, current_scope));
POP_SCOPE();
return values;
}
static ErrorOr<Crypto::ASN1::BitStringView> parse_key_usage(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// KeyUsage ::= BIT STRING {
// digitalSignature (0),
// contentCommitment (1),
// keyEncipherment (2),
// dataEncipherment (3),
// keyAgreement (4),
// keyCertSign (5),
// cRLSign (6),
// encipherOnly (7),
// decipherOnly (8)
// }
PUSH_SCOPE("KeyUsage"sv);
READ_OBJECT(BitString, Crypto::ASN1::BitStringView, usage);
POP_SCOPE();
return usage;
}
static ErrorOr<BasicConstraints> parse_basic_constraints(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// BasicConstraints ::= SEQUENCE {
// cA BOOLEAN DEFAULT FALSE,
// pathLenConstraint INTEGER (0..MAX) OPTIONAL
// }
BasicConstraints constraints {};
ENTER_TYPED_SCOPE(Sequence, "BasicConstraints"sv);
if (decoder.eof()) {
EXIT_SCOPE();
return constraints;
}
auto ca_tag = TRY(decoder.peek());
if (ca_tag.kind == Crypto::ASN1::Kind::Boolean) {
PUSH_SCOPE("cA"sv);
READ_OBJECT(Boolean, bool, is_certificate_authority);
constraints.is_certificate_authority = is_certificate_authority;
POP_SCOPE();
}
if (decoder.eof()) {
EXIT_SCOPE();
return constraints;
}
auto path_length_tag = TRY(decoder.peek());
if (path_length_tag.kind == Crypto::ASN1::Kind::Integer) {
PUSH_SCOPE("pathLenConstraint"sv);
READ_OBJECT(Integer, Crypto::UnsignedBigInteger, path_length_constraint);
constraints.path_length_constraint = path_length_constraint;
POP_SCOPE();
}
EXIT_SCOPE();
return constraints;
}
static ErrorOr<void> parse_extension(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope, Certificate& certificate)
{
// Extension ::= Sequence {
// extension_id ObjectIdentifier,
// critical Boolean DEFAULT false,
// extension_value OctetString (DER-encoded)
// }
ENTER_TYPED_SCOPE(Sequence, "Extension"sv);
PUSH_SCOPE("extension_id"sv);
READ_OBJECT(ObjectIdentifier, Vector<int>, extension_id);
POP_SCOPE();
bool is_critical = false;
auto peek = TRY(decoder.peek());
if (peek.kind == Crypto::ASN1::Kind::Boolean) {
PUSH_SCOPE("critical"sv);
READ_OBJECT(Boolean, bool, extension_critical);
is_critical = extension_critical;
POP_SCOPE();
}
PUSH_SCOPE("extension_value"sv);
READ_OBJECT(OctetString, StringView, extension_value);
POP_SCOPE();
bool is_known_extension = false;
Crypto::ASN1::Decoder extension_decoder { extension_value.bytes() };
Vector<StringView, 8> extension_scope {};
if (extension_id == subject_alternative_name_oid) {
is_known_extension = true;
auto alternate_names = TRY(parse_subject_alternative_names(extension_decoder, extension_scope));
certificate.SAN = alternate_names;
}
if (extension_id == key_usage_oid) {
is_known_extension = true;
auto usage = TRY(parse_key_usage(extension_decoder, extension_scope));
certificate.is_allowed_to_sign_certificate = usage.get(5);
}
if (extension_id == basic_constraints_oid) {
is_known_extension = true;
auto constraints = TRY(parse_basic_constraints(extension_decoder, extension_scope));
certificate.is_certificate_authority = constraints.is_certificate_authority;
certificate.path_length_constraint = constraints.path_length_constraint.to_u64();
}
if (extension_id == issuer_alternative_name_oid) {
is_known_extension = true;
auto alternate_names = TRY(parse_issuer_alternative_names(extension_decoder, extension_scope));
certificate.IAN = alternate_names;
}
EXIT_SCOPE();
if (is_critical && !is_known_extension) {
ERROR_WITH_SCOPE(TRY(String::formatted("Extension {} is critical, but we do not support it", extension_id)));
}
if (!is_known_extension) {
dbgln_if(TLS_DEBUG, TRY(String::formatted("{}: Unhandled extension: {}", current_scope, extension_id)));
}
return {};
}
static ErrorOr<void> parse_extensions(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope, Certificate& certificate)
{
// Extensions ::= Sequence OF Extension
ENTER_TYPED_SCOPE(Sequence, "Extensions"sv);
while (!decoder.eof()) {
TRY(parse_extension(decoder, current_scope, certificate));
}
EXIT_SCOPE();
return {};
}
static ErrorOr<Certificate> parse_tbs_certificate(Crypto::ASN1::Decoder& decoder, Vector<StringView> current_scope)
{
// TBSCertificate ::= SEQUENCE {
// version [0] Version DEFAULT v1,
// serialNumber CertificateSerialNumber,
// signature AlgorithmIdentifier{{SupportedAlgorithms}},
// issuer Name,
// validity Validity,
// subject Name,
// subjectPublicKeyInfo SubjectPublicKeyInfo,
// issuerUniqueIdentifier [1] IMPLICIT UniqueIdentifier OPTIONAL,
// ...,
// [[2: -- if present, version shall be v2 or v3
// subjectUniqueIdentifier [2] IMPLICIT UniqueIdentifier OPTIONAL]],
// [[3: -- if present, version shall be v2 or v3
// extensions [3] Extensions OPTIONAL]]
// -- If present, version shall be v3]]
// }
// Note: Parse out the ASN.1 of this object, since its used for TLS verification.
// To do this, we get the bytes of our parent, the size of ourself, and slice the parent buffer.
auto pre_cert_buffer = TRY(decoder.peek_entry_bytes());
// FIXME: Dont assume this value.
// Note: we assume this to be 4. 1 for the tag, and 3 for the length.
auto entry_length_byte_count = 4;
ENTER_TYPED_SCOPE(Sequence, "TBSCertificate"sv);
auto post_cert_buffer = TRY(decoder.peek_entry_bytes());
auto asn1_data = TRY(ByteBuffer::copy(pre_cert_buffer.slice(0, post_cert_buffer.size() + entry_length_byte_count)));
Certificate certificate;
certificate.tbs_asn1 = asn1_data;
certificate.version = TRY(parse_certificate_version(decoder, current_scope)).to_u64();
certificate.serial_number = TRY(parse_serial_number(decoder, current_scope));
certificate.algorithm = TRY(parse_algorithm_identifier(decoder, current_scope));
certificate.issuer = TRY(parse_name(decoder, current_scope));
certificate.validity = TRY(parse_validity(decoder, current_scope));
certificate.subject = TRY(parse_name(decoder, current_scope));
certificate.public_key = TRY(parse_subject_public_key_info(decoder, current_scope));
if (!decoder.eof()) {
auto tag = TRY(decoder.peek());
if (static_cast<u8>(tag.kind) == 1) {
REWRITE_TAG(BitString)
TRY(parse_unique_identifier(decoder, current_scope));
}
}
if (!decoder.eof()) {
auto tag = TRY(decoder.peek());
if (static_cast<u8>(tag.kind) == 2) {
REWRITE_TAG(BitString)
TRY(parse_unique_identifier(decoder, current_scope));
}
}
if (!decoder.eof()) {
auto tag = TRY(decoder.peek());
if (static_cast<u8>(tag.kind) == 3) {
REWRITE_TAG(Sequence)
ENTER_TYPED_SCOPE(Sequence, "extensions"sv);
TRY(parse_extensions(decoder, current_scope, certificate));
EXIT_SCOPE();
}
}
if (!decoder.eof()) {
ERROR_WITH_SCOPE("Reached end of TBS parse with more data left"sv);
}
certificate.is_self_issued = TRY(certificate.issuer.to_string()) == TRY(certificate.subject.to_string());
EXIT_SCOPE();
return certificate;
}
ErrorOr<Certificate> Certificate::parse_certificate(ReadonlyBytes buffer, bool)
{
Crypto::ASN1::Decoder decoder { buffer };
Vector<StringView, 8> current_scope {};
// Certificate ::= SIGNED{TBSCertificate}
// SIGNED{ToBeSigned} ::= SEQUENCE {
// toBeSigned ToBeSigned,
// COMPONENTS OF SIGNATURE{ToBeSigned},
// }
// SIGNATURE{ToBeSigned} ::= SEQUENCE {
// algorithmIdentifier AlgorithmIdentifier{{SupportedAlgorithms}},
// encrypted ENCRYPTED-HASH{ToBeSigned},
// }
// ENCRYPTED-HASH{ToBeSigned} ::= BIT STRING (CONSTRAINED BY {
// -- shall be the result of applying a hashing procedure to the DER-encoded (see 6.2)
// -- octets of a value of -- ToBeSigned -- and then applying an encipherment procedure
// -- to those octets -- } )
ENTER_TYPED_SCOPE(Sequence, "Certificate"sv);
Certificate certificate = TRY(parse_tbs_certificate(decoder, current_scope));
certificate.original_asn1 = TRY(ByteBuffer::copy(buffer));
certificate.signature_algorithm = TRY(parse_algorithm_identifier(decoder, current_scope));
PUSH_SCOPE("signature"sv);
READ_OBJECT(BitString, Crypto::ASN1::BitStringView, signature);
certificate.signature_value = TRY(ByteBuffer::copy(TRY(signature.raw_bytes())));
POP_SCOPE();
if (!decoder.eof()) {
ERROR_WITH_SCOPE("Reached end of Certificate parse with more data left"sv);
}
EXIT_SCOPE();
return certificate;
}
#undef PUSH_SCOPE
#undef ENTER_SCOPE
#undef ENTER_TYPED_SCOPE
#undef POP_SCOPE
#undef EXIT_SCOPE
#undef READ_OBJECT
#undef DROP_OBJECT
#undef REWRITE_TAG
ErrorOr<String> RelativeDistinguishedName::to_string() const
{
#define ADD_IF_RECOGNIZED(identifier, shorthand_code) \
if (it->key == identifier) { \
cert_name.appendff("\\{}={}", shorthand_code, it->value); \
continue; \
}
StringBuilder cert_name;
for (auto it = m_members.begin(); it != m_members.end(); ++it) {
ADD_IF_RECOGNIZED(enum_value(AttributeType::SerialNumber), "SERIALNUMBER");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Email), "MAIL");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Title), "T");
ADD_IF_RECOGNIZED(enum_value(AttributeType::PostalCode), "PC");
ADD_IF_RECOGNIZED(enum_value(AttributeType::DnQualifier), "DNQ");
ADD_IF_RECOGNIZED(enum_value(AttributeType::GivenName), "GIVENNAME");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Surname), "SN");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Cn), "CN");
ADD_IF_RECOGNIZED(enum_value(AttributeType::L), "L");
ADD_IF_RECOGNIZED(enum_value(AttributeType::St), "ST");
ADD_IF_RECOGNIZED(enum_value(AttributeType::O), "O");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Ou), "OU");
ADD_IF_RECOGNIZED(enum_value(AttributeType::C), "C");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Street), "STREET");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Dc), "DC");
ADD_IF_RECOGNIZED(enum_value(AttributeType::Uid), "UID");
cert_name.appendff("\\{}={}", it->key, it->value);
}
#undef ADD_IF_RECOGNIZED
return cert_name.to_string();
}
}