ladybird/Userland/Libraries/LibTLS/TLSv12.cpp

925 lines
40 KiB
C++

/*
* Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Debug.h>
#include <AK/Endian.h>
#include <LibCore/ConfigFile.h>
#include <LibCore/DateTime.h>
#include <LibCore/File.h>
#include <LibCore/FileStream.h>
#include <LibCore/Timer.h>
#include <LibCrypto/ASN1/ASN1.h>
#include <LibCrypto/ASN1/DER.h>
#include <LibCrypto/ASN1/PEM.h>
#include <LibCrypto/PK/Code/EMSA_PSS.h>
#include <LibTLS/TLSv12.h>
#include <errno.h>
#ifndef SOCK_NONBLOCK
# include <sys/ioctl.h>
#endif
namespace TLS {
constexpr static Array<int, 4>
common_name_oid { 2, 5, 4, 3 },
country_name_oid { 2, 5, 4, 6 },
locality_name_oid { 2, 5, 4, 7 },
organization_name_oid { 2, 5, 4, 10 },
organizational_unit_name_oid { 2, 5, 4, 11 };
constexpr static Array<int, 7>
rsa_encryption_oid { 1, 2, 840, 113549, 1, 1, 1 },
rsa_md5_encryption_oid { 1, 2, 840, 113549, 1, 1, 4 },
rsa_sha1_encryption_oid { 1, 2, 840, 113549, 1, 1, 5 },
rsa_sha256_encryption_oid { 1, 2, 840, 113549, 1, 1, 11 },
rsa_sha512_encryption_oid { 1, 2, 840, 113549, 1, 1, 13 };
constexpr static Array<int, 4>
subject_alternative_name_oid { 2, 5, 29, 17 };
Optional<Certificate> TLSv12::parse_asn1(ReadonlyBytes buffer, bool) const
{
#define ENTER_SCOPE_WITHOUT_TYPECHECK(scope) \
do { \
if (auto result = decoder.enter(); result.has_value()) { \
dbgln_if(TLS_DEBUG, "Failed to enter object (" scope "): {}", result.value()); \
return {}; \
} \
} while (0)
#define ENTER_SCOPE_OR_FAIL(kind_name, scope) \
do { \
if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::kind_name) { \
if constexpr (TLS_DEBUG) { \
if (tag.is_error()) \
dbgln(scope " data was invalid: {}", tag.error()); \
else \
dbgln(scope " data was not of kind " #kind_name); \
} \
return {}; \
} \
ENTER_SCOPE_WITHOUT_TYPECHECK(scope); \
} while (0)
#define EXIT_SCOPE(scope) \
do { \
if (auto error = decoder.leave(); error.has_value()) { \
dbgln_if(TLS_DEBUG, "Error while exiting scope " scope ": {}", error.value()); \
return {}; \
} \
} while (0)
#define ENSURE_OBJECT_KIND(_kind_name, scope) \
do { \
if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::_kind_name) { \
if constexpr (TLS_DEBUG) { \
if (tag.is_error()) \
dbgln(scope " data was invalid: {}", tag.error()); \
else \
dbgln(scope " data was not of kind " #_kind_name ", it was {}", Crypto::ASN1::kind_name(tag.value().kind)); \
} \
return {}; \
} \
} while (0)
#define READ_OBJECT_OR_FAIL(kind_name, type_name, value_name, scope) \
auto value_name##_result = decoder.read<type_name>(Crypto::ASN1::Class::Universal, Crypto::ASN1::Kind::kind_name); \
if (value_name##_result.is_error()) { \
dbgln_if(TLS_DEBUG, scope " read of kind " #kind_name " failed: {}", value_name##_result.error()); \
return {}; \
} \
auto value_name = value_name##_result.release_value();
#define DROP_OBJECT_OR_FAIL(scope) \
do { \
if (auto error = decoder.drop(); error.has_value()) { \
dbgln_if(TLS_DEBUG, scope " read failed: {}", error.value()); \
} \
} while (0)
Certificate certificate;
Crypto::ASN1::Decoder decoder { buffer };
// Certificate ::= Sequence {
// certificate TBSCertificate,
// signature_algorithm AlgorithmIdentifier,
// signature_value BitString
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate");
// TBSCertificate ::= Sequence {
// version (0) EXPLICIT Version DEFAULT v1,
// serial_number CertificateSerialNumber,
// signature AlgorithmIdentifier,
// issuer Name,
// validity Validity,
// subject Name,
// subject_public_key_info SubjectPublicKeyInfo,
// issuer_unique_id (1) IMPLICIT UniqueIdentifer OPTIONAL (if present, version > v1),
// subject_unique_id (2) IMPLICIT UniqueIdentiier OPTIONAL (if present, version > v1),
// extensions (3) EXPLICIT Extensions OPTIONAL (if present, version > v2)
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate");
// version
{
// Version :: Integer { v1(0), v2(1), v3(2) } (Optional)
if (auto tag = decoder.peek(); !tag.is_error() && tag.value().type == Crypto::ASN1::Type::Constructed) {
ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::version");
READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::version");
if (!(value < 3)) {
dbgln_if(TLS_DEBUG, "Certificate::version Invalid value for version: {}", value.to_base10());
return {};
}
certificate.version = value.words()[0];
EXIT_SCOPE("Certificate::version");
} else {
certificate.version = 0;
}
}
// serial_number
{
// CertificateSerialNumber :: Integer
READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::serial_number");
certificate.serial_number = move(value);
}
auto parse_algorithm_identifier = [&](CertificateKeyAlgorithm& field) -> Optional<bool> {
// AlgorithmIdentifier ::= Sequence {
// algorithm ObjectIdentifier,
// parameters ANY OPTIONAL
// }
ENTER_SCOPE_OR_FAIL(Sequence, "AlgorithmIdentifier");
READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, identifier, "AlgorithmIdentifier::algorithm");
if (identifier == rsa_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_RSA;
else if (identifier == rsa_md5_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_MD5;
else if (identifier == rsa_sha1_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA1;
else if (identifier == rsa_sha256_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA256;
else if (identifier == rsa_sha512_encryption_oid)
field = CertificateKeyAlgorithm ::RSA_SHA512;
else
return {};
EXIT_SCOPE("AlgorithmIdentifier");
return true;
};
// signature
{
if (!parse_algorithm_identifier(certificate.algorithm).has_value())
return {};
}
auto parse_name = [&](auto& name_struct) -> Optional<bool> {
// Name ::= Choice {
// rdn_sequence RDNSequence
// } // NOTE: since this is the only alternative, there's no index
// RDNSequence ::= Sequence OF RelativeDistinguishedName
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject");
// RelativeDistinguishedName ::= Set OF AttributeTypeAndValue
// AttributeTypeAndValue ::= Sequence {
// type AttributeType,
// value AttributeValue
// }
// AttributeType ::= ObjectIdentifier
// AttributeValue ::= Any
while (!decoder.eof()) {
// Parse only the the required fields, and ignore the rest.
ENTER_SCOPE_OR_FAIL(Set, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
while (!decoder.eof()) {
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
ENSURE_OBJECT_KIND(ObjectIdentifier, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type");
if (auto type_identifier_or_error = decoder.read<Vector<int>>(); !type_identifier_or_error.is_error()) {
// Figure out what type of identifier this is
auto& identifier = type_identifier_or_error.value();
if (identifier == common_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.subject = name;
} else if (identifier == country_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.country = name;
} else if (identifier == locality_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.location = name;
} else if (identifier == organization_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.entity = name;
} else if (identifier == organizational_unit_name_oid) {
READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
"Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
name_struct.unit = name;
}
} else {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type data was invalid: {}", type_identifier_or_error.error());
return {};
}
EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
}
EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
}
EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject");
return true;
};
// issuer
{
if (!parse_name(certificate.issuer).has_value())
return {};
}
// validity
{
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Validity");
auto parse_time = [&](Core::DateTime& datetime) -> Optional<bool> {
// Time ::= Choice {
// utc_time UTCTime,
// general_time GeneralizedTime
// }
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time failed to read tag: {}", tag.error());
return {};
};
if (tag.value().kind == Crypto::ASN1::Kind::UTCTime) {
READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
auto result = Crypto::ASN1::parse_utc_time(time);
if (!result.has_value()) {
dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid UTC Time: {}", time);
return {};
}
datetime = result.release_value();
return true;
}
if (tag.value().kind == Crypto::ASN1::Kind::GeneralizedTime) {
READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
auto result = Crypto::ASN1::parse_generalized_time(time);
if (!result.has_value()) {
dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid Generalized Time: {}", time);
return {};
}
datetime = result.release_value();
return true;
}
dbgln_if(1, "Unrecognised Time format {}", Crypto::ASN1::kind_name(tag.value().kind));
return {};
};
if (!parse_time(certificate.not_before).has_value())
return {};
if (!parse_time(certificate.not_after).has_value())
return {};
EXIT_SCOPE("Certificate::TBSCertificate::Validity");
}
// subject
{
if (!parse_name(certificate.subject).has_value())
return {};
}
// subject_public_key_info
{
// SubjectPublicKeyInfo ::= Sequence {
// algorithm AlgorithmIdentifier,
// subject_public_key BitString
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::subject_public_key_info");
if (!parse_algorithm_identifier(certificate.key_algorithm).has_value())
return {};
READ_OBJECT_OR_FAIL(BitString, const BitmapView, value, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info");
// Note: Once we support other kinds of keys, make sure to check the kind here!
auto key = Crypto::PK::RSA::parse_rsa_key({ value.data(), value.size_in_bytes() });
if (!key.public_key.length()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info: Invalid key");
return {};
}
certificate.public_key = move(key.public_key);
EXIT_SCOPE("Certificate::TBSCertificate::subject_public_key_info");
}
auto parse_unique_identifier = [&]() -> Optional<bool> {
if (certificate.version == 0)
return true;
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
return {};
}
// The spec says to just ignore these.
if (static_cast<u8>(tag.value().kind) == 1 || static_cast<u8>(tag.value().kind) == 2)
DROP_OBJECT_OR_FAIL("UniqueIdentifier");
return true;
};
// issuer_unique_identifier
{
if (!parse_unique_identifier().has_value())
return {};
}
// subject_unique_identifier
{
if (!parse_unique_identifier().has_value())
return {};
}
// extensions
{
if (certificate.version == 2) {
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
return {};
}
if (static_cast<u8>(tag.value().kind) == 3) {
// Extensions ::= Sequence OF Extension
// Extension ::= Sequence {
// extension_id ObjectIdentifier,
// critical Boolean DEFAULT false,
// extension_value OctetString (DER-encoded)
// }
ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::TBSCertificate::Extensions(IMPLICIT)");
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions");
while (!decoder.eof()) {
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension");
READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, extension_id, "Certificate::TBSCertificate::Extensions::$::Extension::extension_id");
bool is_critical = false;
if (auto tag = decoder.peek(); !tag.is_error() && tag.value().kind == Crypto::ASN1::Kind::Boolean) {
// Read the 'critical' property
READ_OBJECT_OR_FAIL(Boolean, bool, critical, "Certificate::TBSCertificate::Extensions::$::Extension::critical");
is_critical = critical;
}
READ_OBJECT_OR_FAIL(OctetString, StringView, extension_value, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value");
// Figure out what this extension is.
if (extension_id == subject_alternative_name_oid) {
Crypto::ASN1::Decoder decoder { extension_value.bytes() };
// SubjectAlternativeName ::= GeneralNames
// GeneralNames ::= Sequence OF GeneralName
// GeneralName ::= CHOICE {
// other_name (0) OtherName,
// rfc_822_name (1) IA5String,
// dns_name (2) IA5String,
// x400Address (3) ORAddress,
// directory_name (4) Name,
// edi_party_name (5) EDIPartyName,
// uri (6) IA5String,
// ip_address (7) OctetString,
// registered_id (8) ObjectIdentifier,
// }
ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName");
while (!decoder.eof()) {
auto tag = decoder.peek();
if (tag.is_error()) {
dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$ could not read tag: {}", tag.error());
return {};
}
auto tag_value = static_cast<u8>(tag.value().kind);
switch (tag_value) {
case 0:
// OtherName
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::OtherName");
break;
case 1:
// RFC 822 name
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RFC822Name");
break;
case 2: {
// DNS Name
READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DNSName");
certificate.SAN.append(name);
break;
}
case 3:
// x400Address
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::X400Adress");
break;
case 4:
// Directory name
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DirectoryName");
break;
case 5:
// edi party name
// We don't know how to use this.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::EDIPartyName");
break;
case 6: {
// URI
READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::URI");
certificate.SAN.append(name);
break;
}
case 7:
// IP Address
// We can't handle these.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::IPAddress");
break;
case 8:
// Registered ID
// We can't handle these.
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RegisteredID");
break;
default:
dbgln_if(TLS_DEBUG, "Unknown tag in SAN choice {}", tag_value);
if (is_critical)
return {};
else
DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::???");
}
}
}
EXIT_SCOPE("Certificate::TBSCertificate::Extensions::$::Extension");
}
EXIT_SCOPE("Certificate::TBSCertificate::Extensions");
EXIT_SCOPE("Certificate::TBSCertificate::Extensions(IMPLICIT)");
}
}
}
// Just ignore the rest of the data for now.
EXIT_SCOPE("Certificate::TBSCertificate");
EXIT_SCOPE("Certificate");
dbgln_if(TLS_DEBUG, "Certificate issued for {} by {}", certificate.subject.subject, certificate.issuer.subject);
return certificate;
#undef DROP_OBJECT_OR_FAIL
#undef ENSURE_OBJECT_KIND
#undef ENTER_SCOPE_OR_FAIL
#undef ENTER_SCOPE_WITHOUT_TYPECHECK
#undef EXIT_SCOPE
#undef READ_OBJECT_OR_FAIL
}
ssize_t TLSv12::handle_certificate(ReadonlyBytes buffer)
{
ssize_t res = 0;
if (buffer.size() < 3) {
#if TLS_DEBUG
dbgln("not enough certificate header data");
#endif
return (i8)Error::NeedMoreData;
}
u32 certificate_total_length = buffer[0] * 0x10000 + buffer[1] * 0x100 + buffer[2];
dbgln_if(TLS_DEBUG, "total length: {}", certificate_total_length);
if (certificate_total_length <= 4)
return 3 * certificate_total_length;
res += 3;
if (certificate_total_length > buffer.size() - res) {
#if TLS_DEBUG
dbgln("not enough data for claimed total cert length");
#endif
return (i8)Error::NeedMoreData;
}
size_t size = certificate_total_length;
size_t index = 0;
bool valid_certificate = false;
while (size > 0) {
++index;
if (buffer.size() - res < 3) {
#if TLS_DEBUG
dbgln("not enough data for certificate length");
#endif
return (i8)Error::NeedMoreData;
}
size_t certificate_size = buffer[res] * 0x10000 + buffer[res + 1] * 0x100 + buffer[res + 2];
res += 3;
if (buffer.size() - res < certificate_size) {
#if TLS_DEBUG
dbgln("not enough data for certificate body");
#endif
return (i8)Error::NeedMoreData;
}
auto res_cert = res;
auto remaining = certificate_size;
size_t certificates_in_chain = 0;
do {
if (remaining <= 3) {
dbgln("Ran out of data");
break;
}
++certificates_in_chain;
if (buffer.size() < (size_t)res_cert + 3) {
dbgln("not enough data to read cert size ({} < {})", buffer.size(), res_cert + 3);
break;
}
size_t certificate_size_specific = buffer[res_cert] * 0x10000 + buffer[res_cert + 1] * 0x100 + buffer[res_cert + 2];
res_cert += 3;
remaining -= 3;
if (certificate_size_specific > remaining) {
dbgln("invalid certificate size (expected {} but got {})", remaining, certificate_size_specific);
break;
}
remaining -= certificate_size_specific;
auto certificate = parse_asn1(buffer.slice(res_cert, certificate_size_specific), false);
if (certificate.has_value()) {
if (certificate.value().is_valid()) {
m_context.certificates.append(certificate.value());
valid_certificate = true;
}
}
res_cert += certificate_size_specific;
} while (remaining > 0);
if (remaining) {
dbgln("extraneous {} bytes left over after parsing certificates", remaining);
}
size -= certificate_size + 3;
res += certificate_size;
}
if (!valid_certificate)
return (i8)Error::UnsupportedCertificate;
if ((size_t)res != buffer.size())
dbgln("some data left unread: {} bytes out of {}", res, buffer.size());
return res;
}
void TLSv12::consume(ReadonlyBytes record)
{
if (m_context.critical_error) {
dbgln("There has been a critical error ({}), refusing to continue", (i8)m_context.critical_error);
return;
}
if (record.size() == 0) {
return;
}
dbgln_if(TLS_DEBUG, "Consuming {} bytes", record.size());
m_context.message_buffer.append(record.data(), record.size());
size_t index { 0 };
size_t buffer_length = m_context.message_buffer.size();
size_t size_offset { 3 }; // read the common record header
size_t header_size { 5 };
dbgln_if(TLS_DEBUG, "message buffer length {}", buffer_length);
while (buffer_length >= 5) {
auto length = AK::convert_between_host_and_network_endian(*(u16*)m_context.message_buffer.offset_pointer(index + size_offset)) + header_size;
if (length > buffer_length) {
dbgln_if(TLS_DEBUG, "Need more data: {} > {}", length, buffer_length);
break;
}
auto consumed = handle_message(m_context.message_buffer.bytes().slice(index, length));
if constexpr (TLS_DEBUG) {
if (consumed > 0)
dbgln("consumed {} bytes", consumed);
else
dbgln("error: {}", consumed);
}
if (consumed != (i8)Error::NeedMoreData) {
if (consumed < 0) {
dbgln("Consumed an error: {}", consumed);
if (!m_context.critical_error)
m_context.critical_error = (i8)consumed;
m_context.error_code = (Error)consumed;
break;
}
} else {
continue;
}
index += length;
buffer_length -= length;
if (m_context.critical_error) {
dbgln("Broken connection");
m_context.error_code = Error::BrokenConnection;
break;
}
}
if (m_context.error_code != Error::NoError && m_context.error_code != Error::NeedMoreData) {
dbgln("consume error: {}", (i8)m_context.error_code);
m_context.message_buffer.clear();
return;
}
if (index) {
m_context.message_buffer = m_context.message_buffer.slice(index, m_context.message_buffer.size() - index);
}
}
void TLSv12::ensure_hmac(size_t digest_size, bool local)
{
if (local && m_hmac_local)
return;
if (!local && m_hmac_remote)
return;
auto hash_kind = Crypto::Hash::HashKind::None;
switch (digest_size) {
case Crypto::Hash::SHA1::DigestSize:
hash_kind = Crypto::Hash::HashKind::SHA1;
break;
case Crypto::Hash::SHA256::DigestSize:
hash_kind = Crypto::Hash::HashKind::SHA256;
break;
case Crypto::Hash::SHA512::DigestSize:
hash_kind = Crypto::Hash::HashKind::SHA512;
break;
default:
dbgln("Failed to find a suitable hash for size {}", digest_size);
break;
}
auto hmac = make<Crypto::Authentication::HMAC<Crypto::Hash::Manager>>(ReadonlyBytes { local ? m_context.crypto.local_mac : m_context.crypto.remote_mac, digest_size }, hash_kind);
if (local)
m_hmac_local = move(hmac);
else
m_hmac_remote = move(hmac);
}
bool Certificate::is_valid() const
{
auto now = Core::DateTime::now();
if (now < not_before) {
dbgln("certificate expired (not yet valid, signed for {})", not_before.to_string());
return false;
}
if (not_after < now) {
dbgln("certificate expired (expiry date {})", not_after.to_string());
return false;
}
return true;
}
void TLSv12::try_disambiguate_error() const
{
dbgln("Possible failure cause(s): ");
switch ((AlertDescription)m_context.critical_error) {
case AlertDescription::HandshakeFailure:
if (!m_context.cipher_spec_set) {
dbgln("- No cipher suite in common with {}", m_context.extensions.SNI);
} else {
dbgln("- Unknown internal issue");
}
break;
case AlertDescription::InsufficientSecurity:
dbgln("- No cipher suite in common with {} (the server is oh so secure)", m_context.extensions.SNI);
break;
case AlertDescription::ProtocolVersion:
dbgln("- The server refused to negotiate with TLS 1.2 :(");
break;
case AlertDescription::UnexpectedMessage:
dbgln("- We sent an invalid message for the state we're in.");
break;
case AlertDescription::BadRecordMAC:
dbgln("- Bad MAC record from our side.");
dbgln("- Ciphertext wasn't an even multiple of the block length.");
dbgln("- Bad block cipher padding.");
dbgln("- If both sides are compliant, the only cause is messages being corrupted in the network.");
break;
case AlertDescription::RecordOverflow:
dbgln("- Sent a ciphertext record which has a length bigger than 18432 bytes.");
dbgln("- Sent record decrypted to a compressed record that has a length bigger than 18432 bytes.");
dbgln("- If both sides are compliant, the only cause is messages being corrupted in the network.");
break;
case AlertDescription::DecompressionFailure:
dbgln("- We sent invalid input for decompression (e.g. data that would expand to excessive length)");
break;
case AlertDescription::IllegalParameter:
dbgln("- We sent a parameter in the handshake that is out of range or inconsistent with the other parameters.");
break;
case AlertDescription::DecodeError:
dbgln("- The message we sent cannot be decoded because a field was out of range or the length was incorrect.");
dbgln("- If both sides are compliant, the only cause is messages being corrupted in the network.");
break;
case AlertDescription::DecryptError:
dbgln("- A handshake crypto operation failed. This includes signature verification and validating Finished.");
break;
case AlertDescription::AccessDenied:
dbgln("- The certificate is valid, but once access control was applied, the sender decided to stop negotiation.");
break;
case AlertDescription::InternalError:
dbgln("- No one knows, but it isn't a protocol failure.");
break;
case AlertDescription::DecryptionFailed:
case AlertDescription::NoCertificate:
case AlertDescription::ExportRestriction:
dbgln("- No one knows, the server sent a non-compliant alert.");
break;
default:
dbgln("- No one knows.");
break;
}
}
void TLSv12::set_root_certificates(Vector<Certificate> certificates)
{
if (!m_context.root_ceritificates.is_empty())
dbgln("TLS warn: resetting root certificates!");
for (auto& cert : certificates) {
if (!cert.is_valid())
dbgln("Certificate for {} by {} is invalid, things may or may not work!", cert.subject.subject, cert.issuer.subject);
// FIXME: Figure out what we should do when our root certs are invalid.
}
m_context.root_ceritificates = move(certificates);
}
bool Context::verify_chain() const
{
if (!options.validate_certificates)
return true;
const Vector<Certificate>* local_chain = nullptr;
if (is_server) {
dbgln("Unsupported: Server mode");
TODO();
} else {
local_chain = &certificates;
}
// FIXME: Actually verify the signature, instead of just checking the name.
HashMap<String, String> chain;
HashTable<String> roots;
// First, walk the root certs.
for (auto& cert : root_ceritificates) {
roots.set(cert.subject.subject);
chain.set(cert.subject.subject, cert.issuer.subject);
}
// Then, walk the local certs.
for (auto& cert : *local_chain) {
auto& issuer_unique_name = cert.issuer.unit.is_empty() ? cert.issuer.subject : cert.issuer.unit;
chain.set(cert.subject.subject, issuer_unique_name);
}
// Then verify the chain.
for (auto& it : chain) {
if (it.key == it.value) { // Allow self-signed certificates.
if (!roots.contains(it.key))
dbgln("Self-signed warning: Certificate for {} is self-signed", it.key);
continue;
}
auto ref = chain.get(it.value);
if (!ref.has_value()) {
dbgln("Certificate for {} is not signed by anyone we trust ({})", it.key, it.value);
return false;
}
if (ref.value() == it.key) // Allow (but warn about) mutually recursively signed cert A <-> B.
dbgln("Co-dependency warning: Certificate for {} is issued by {}, which itself is issued by {}", ref.value(), it.key, ref.value());
}
return true;
}
static bool wildcard_matches(const StringView& host, const StringView& subject)
{
if (host.matches(subject))
return true;
if (subject.starts_with("*."))
return wildcard_matches(host, subject.substring_view(2));
return false;
}
Optional<size_t> TLSv12::verify_chain_and_get_matching_certificate(const StringView& host) const
{
if (m_context.certificates.is_empty() || !m_context.verify_chain())
return {};
if (host.is_empty())
return 0;
for (size_t i = 0; i < m_context.certificates.size(); ++i) {
auto& cert = m_context.certificates[i];
if (wildcard_matches(host, cert.subject.subject))
return i;
for (auto& san : cert.SAN) {
if (wildcard_matches(host, san))
return i;
}
}
return {};
}
TLSv12::TLSv12(Core::Object* parent, Options options)
: Core::Socket(Core::Socket::Type::TCP, parent)
{
m_context.options = move(options);
m_context.is_server = false;
m_context.tls_buffer = ByteBuffer::create_uninitialized(0);
#ifdef SOCK_NONBLOCK
int fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
#else
int fd = socket(AF_INET, SOCK_STREAM, 0);
int option = 1;
ioctl(fd, FIONBIO, &option);
#endif
if (fd < 0) {
set_error(errno);
} else {
set_fd(fd);
set_mode(IODevice::ReadWrite);
set_error(0);
}
}
bool TLSv12::add_client_key(ReadonlyBytes certificate_pem_buffer, ReadonlyBytes rsa_key) // FIXME: This should not be bound to RSA
{
if (certificate_pem_buffer.is_empty() || rsa_key.is_empty()) {
return true;
}
auto decoded_certificate = Crypto::decode_pem(certificate_pem_buffer);
if (decoded_certificate.is_empty()) {
dbgln("Certificate not PEM");
return false;
}
auto maybe_certificate = parse_asn1(decoded_certificate);
if (!maybe_certificate.has_value()) {
dbgln("Invalid certificate");
return false;
}
Crypto::PK::RSA rsa(rsa_key);
auto certificate = maybe_certificate.value();
certificate.private_key = rsa.private_key();
return add_client_key(certificate);
}
AK::Singleton<DefaultRootCACertificates> DefaultRootCACertificates::s_the;
DefaultRootCACertificates::DefaultRootCACertificates()
{
// FIXME: This might not be the best format, find a better way to represent CA certificates.
auto config = Core::ConfigFile::get_for_system("ca_certs");
auto now = Core::DateTime::now();
auto last_year = Core::DateTime::create(now.year() - 1);
auto next_year = Core::DateTime::create(now.year() + 1);
for (auto& entity : config->groups()) {
Certificate cert;
cert.subject.subject = entity;
cert.issuer.subject = config->read_entry(entity, "issuer_subject", entity);
cert.subject.country = config->read_entry(entity, "country");
cert.not_before = Crypto::ASN1::parse_generalized_time(config->read_entry(entity, "not_before", "")).value_or(last_year);
cert.not_after = Crypto::ASN1::parse_generalized_time(config->read_entry(entity, "not_after", "")).value_or(next_year);
m_ca_certificates.append(move(cert));
}
}
}