Libraries: Move to Userland/Libraries/

Userland/Libraries/LibTLS/CMakeLists.txt

@@ -0,0 +1,11 @@
+set(SOURCES
+    ClientHandshake.cpp
+    Exchange.cpp
+    Handshake.cpp
+    Record.cpp
+    Socket.cpp
+    TLSv12.cpp
+)
+
+serenity_lib(LibTLS tls)
+target_link_libraries(LibTLS LibCore LibCrypto)

Userland/Libraries/LibTLS/Certificate.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/Forward.h>
+#include <AK/Singleton.h>
+#include <AK/Types.h>
+#include <LibCrypto/BigInt/UnsignedBigInteger.h>
+#include <LibCrypto/PK/RSA.h>
+
+namespace TLS {
+
+enum class CertificateKeyAlgorithm {
+    Unsupported = 0x00,
+    RSA_RSA = 0x01,
+    RSA_MD5 = 0x04,
+    RSA_SHA1 = 0x05,
+    RSA_SHA256 = 0x0b,
+    RSA_SHA512 = 0x0d,
+};
+
+struct Certificate {
+    u16 version;
+    CertificateKeyAlgorithm algorithm;
+    CertificateKeyAlgorithm key_algorithm;
+    CertificateKeyAlgorithm ec_algorithm;
+    ByteBuffer exponent;
+    Crypto::PK::RSAPublicKey<Crypto::UnsignedBigInteger> public_key;
+    Crypto::PK::RSAPrivateKey<Crypto::UnsignedBigInteger> private_key;
+    String issuer_country;
+    String issuer_state;
+    String issuer_location;
+    String issuer_entity;
+    String issuer_subject;
+    String issuer_unit;
+    String not_before;
+    String not_after;
+    String country;
+    String state;
+    String location;
+    String entity;
+    String subject;
+    String unit;
+    Vector<String> SAN;
+    u8* ocsp;
+    Crypto::UnsignedBigInteger serial_number;
+    ByteBuffer sign_key;
+    ByteBuffer fingerprint;
+    ByteBuffer der;
+    ByteBuffer data;
+
+    bool is_valid() const;
+};
+
+class DefaultRootCACertificates {
+public:
+    DefaultRootCACertificates();
+
+    const Vector<Certificate>& certificates() const { return m_ca_certificates; }
+
+    static DefaultRootCACertificates& the() { return s_the; }
+
+private:
+    static AK::Singleton<DefaultRootCACertificates> s_the;
+
+    Vector<Certificate> m_ca_certificates;
+};
+
+}
+
+using TLS::Certificate;
+using TLS::DefaultRootCACertificates;

Userland/Libraries/LibTLS/ClientHandshake.cpp

@@ -0,0 +1,667 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Endian.h>
+#include <AK/Random.h>
+
+#include <LibCore/Timer.h>
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/PK/Code/EMSA_PSS.h>
+#include <LibTLS/TLSv12.h>
+
+namespace TLS {
+
+ssize_t TLSv12::handle_server_hello_done(ReadonlyBytes buffer)
+{
+    if (buffer.size() < 3)
+        return (i8)Error::NeedMoreData;
+
+    size_t size = buffer[0] * 0x10000 + buffer[1] * 0x100 + buffer[2];
+
+    if (buffer.size() - 3 < size)
+        return (i8)Error::NeedMoreData;
+
+    return size + 3;
+}
+
+ssize_t TLSv12::handle_hello(ReadonlyBytes buffer, WritePacketStage& write_packets)
+{
+    write_packets = WritePacketStage::Initial;
+    if (m_context.connection_status != ConnectionStatus::Disconnected && m_context.connection_status != ConnectionStatus::Renegotiating) {
+        dbgln("unexpected hello message");
+        return (i8)Error::UnexpectedMessage;
+    }
+    ssize_t res = 0;
+    size_t min_hello_size = 41;
+
+    if (min_hello_size > buffer.size()) {
+        dbgln("need more data");
+        return (i8)Error::NeedMoreData;
+    }
+    size_t following_bytes = buffer[0] * 0x10000 + buffer[1] * 0x100 + buffer[2];
+    res += 3;
+    if (buffer.size() - res < following_bytes) {
+        dbg() << "not enough data after header: " << buffer.size() - res << " < " << following_bytes;
+        return (i8)Error::NeedMoreData;
+    }
+
+    if (buffer.size() - res < 2) {
+        dbgln("not enough data for version");
+        return (i8)Error::NeedMoreData;
+    }
+    auto version = (Version)AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(res));
+
+    res += 2;
+    if (!supports_version(version))
+        return (i8)Error::NotSafe;
+
+    memcpy(m_context.remote_random, buffer.offset_pointer(res), sizeof(m_context.remote_random));
+    res += sizeof(m_context.remote_random);
+
+    u8 session_length = buffer[res++];
+    if (buffer.size() - res < session_length) {
+        dbgln("not enough data for session id");
+        return (i8)Error::NeedMoreData;
+    }
+
+    if (session_length && session_length <= 32) {
+        memcpy(m_context.session_id, buffer.offset_pointer(res), session_length);
+        m_context.session_id_size = session_length;
+#ifdef TLS_DEBUG
+        dbgln("Remote session ID:");
+        print_buffer(ReadonlyBytes { m_context.session_id, session_length });
+#endif
+    } else {
+        m_context.session_id_size = 0;
+    }
+    res += session_length;
+
+    if (buffer.size() - res < 2) {
+        dbgln("not enough data for cipher suite listing");
+        return (i8)Error::NeedMoreData;
+    }
+    auto cipher = (CipherSuite)AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(res));
+    res += 2;
+    if (!supports_cipher(cipher)) {
+        m_context.cipher = CipherSuite::Invalid;
+        dbgln("No supported cipher could be agreed upon");
+        return (i8)Error::NoCommonCipher;
+    }
+    m_context.cipher = cipher;
+#ifdef TLS_DEBUG
+    dbg() << "Cipher: " << (u16)cipher;
+#endif
+
+    // The handshake hash function is _always_ SHA256
+    m_context.handshake_hash.initialize(Crypto::Hash::HashKind::SHA256);
+
+    if (buffer.size() - res < 1) {
+        dbgln("not enough data for compression spec");
+        return (i8)Error::NeedMoreData;
+    }
+    u8 compression = buffer[res++];
+    if (compression != 0) {
+        dbgln("Server told us to compress, we will not!");
+        return (i8)Error::CompressionNotSupported;
+    }
+
+    if (res > 0) {
+        if (m_context.connection_status != ConnectionStatus::Renegotiating)
+            m_context.connection_status = ConnectionStatus::Negotiating;
+        if (m_context.is_server) {
+            dbgln("unsupported: server mode");
+            write_packets = WritePacketStage::ServerHandshake;
+        }
+    }
+
+    if (res > 2) {
+        res += 2;
+    }
+
+    while ((ssize_t)buffer.size() - res >= 4) {
+        auto extension_type = (HandshakeExtension)AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(res));
+        res += 2;
+        u16 extension_length = AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(res));
+        res += 2;
+
+#ifdef TLS_DEBUG
+        dbg() << "extension " << (u16)extension_type << " with length " << extension_length;
+#endif
+        if (extension_length) {
+            if (buffer.size() - res < extension_length) {
+                dbgln("not enough data for extension");
+                return (i8)Error::NeedMoreData;
+            }
+
+            // SNI
+            if (extension_type == HandshakeExtension::ServerName) {
+                u16 sni_host_length = AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(res + 3));
+                if (buffer.size() - res - 5 < sni_host_length) {
+                    dbg() << "Not enough data for sni " << (buffer.size() - res - 5) << " < " << sni_host_length;
+                    return (i8)Error::NeedMoreData;
+                }
+
+                if (sni_host_length) {
+                    m_context.SNI = String { (const char*)buffer.offset_pointer(res + 5), sni_host_length };
+                    dbg() << "server name indicator: " << m_context.SNI;
+                }
+            } else if (extension_type == HandshakeExtension::ApplicationLayerProtocolNegotiation && m_context.alpn.size()) {
+                if (buffer.size() - res > 2) {
+                    auto alpn_length = AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(res));
+                    if (alpn_length && alpn_length <= extension_length - 2) {
+                        const u8* alpn = buffer.offset_pointer(res + 2);
+                        size_t alpn_position = 0;
+                        while (alpn_position < alpn_length) {
+                            u8 alpn_size = alpn[alpn_position++];
+                            if (alpn_size + alpn_position >= extension_length)
+                                break;
+                            String alpn_str { (const char*)alpn + alpn_position, alpn_length };
+                            if (alpn_size && m_context.alpn.contains_slow(alpn_str)) {
+                                m_context.negotiated_alpn = alpn_str;
+                                dbg() << "negotiated alpn: " << alpn_str;
+                                break;
+                            }
+                            alpn_position += alpn_length;
+                            if (!m_context.is_server) // server hello must contain one ALPN
+                                break;
+                        }
+                    }
+                }
+            } else if (extension_type == HandshakeExtension::SignatureAlgorithms) {
+                dbgln("supported signatures: ");
+                print_buffer(buffer.slice(res, extension_length));
+                // FIXME: what are we supposed to do here?
+            }
+            res += extension_length;
+        }
+    }
+
+    return res;
+}
+
+ssize_t TLSv12::handle_finished(ReadonlyBytes buffer, WritePacketStage& write_packets)
+{
+    if (m_context.connection_status < ConnectionStatus::KeyExchange || m_context.connection_status == ConnectionStatus::Established) {
+        dbgln("unexpected finished message");
+        return (i8)Error::UnexpectedMessage;
+    }
+
+    write_packets = WritePacketStage::Initial;
+
+    if (buffer.size() < 3) {
+        return (i8)Error::NeedMoreData;
+    }
+
+    size_t index = 3;
+
+    u32 size = buffer[0] * 0x10000 + buffer[1] * 0x100 + buffer[2];
+
+    if (size < 12) {
+#ifdef TLS_DEBUG
+        dbg() << "finished packet smaller than minimum size: " << size;
+#endif
+        return (i8)Error::BrokenPacket;
+    }
+
+    if (size < buffer.size() - index) {
+#ifdef TLS_DEBUG
+        dbg() << "not enough data after length: " << size << " > " << buffer.size() - index;
+#endif
+        return (i8)Error::NeedMoreData;
+    }
+
+// TODO: Compare Hashes
+#ifdef TLS_DEBUG
+    dbgln("FIXME: handle_finished :: Check message validity");
+#endif
+    m_context.connection_status = ConnectionStatus::Established;
+
+    if (m_handshake_timeout_timer) {
+        // Disable the handshake timeout timer as handshake has been established.
+        m_handshake_timeout_timer->stop();
+        m_handshake_timeout_timer->remove_from_parent();
+        m_handshake_timeout_timer = nullptr;
+    }
+
+    if (on_tls_ready_to_write)
+        on_tls_ready_to_write(*this);
+
+    return index + size;
+}
+
+void TLSv12::build_random(PacketBuilder& builder)
+{
+    u8 random_bytes[48];
+    size_t bytes = 48;
+
+    AK::fill_with_random(random_bytes, bytes);
+
+    // remove zeros from the random bytes
+    for (size_t i = 0; i < bytes; ++i) {
+        if (!random_bytes[i])
+            random_bytes[i--] = AK::get_random<u8>();
+    }
+
+    if (m_context.is_server) {
+        dbgln("Server mode not supported");
+        return;
+    } else {
+        *(u16*)random_bytes = AK::convert_between_host_and_network_endian((u16)Version::V12);
+    }
+
+    m_context.premaster_key = ByteBuffer::copy(random_bytes, bytes);
+
+    const auto& certificate_option = verify_chain_and_get_matching_certificate(m_context.SNI); // if the SNI is empty, we'll make a special case and match *a* leaf certificate.
+    if (!certificate_option.has_value()) {
+        dbgln("certificate verification failed :(");
+        alert(AlertLevel::Critical, AlertDescription::BadCertificate);
+        return;
+    }
+
+    auto& certificate = m_context.certificates[certificate_option.value()];
+#ifdef TLS_DEBUG
+    dbgln("PreMaster secret");
+    print_buffer(m_context.premaster_key);
+#endif
+
+    Crypto::PK::RSA_PKCS1_EME rsa(certificate.public_key.modulus(), 0, certificate.public_key.public_exponent());
+
+    u8 out[rsa.output_size()];
+    auto outbuf = Bytes { out, rsa.output_size() };
+    rsa.encrypt(m_context.premaster_key, outbuf);
+
+#ifdef TLS_DEBUG
+    dbgln("Encrypted: ");
+    print_buffer(outbuf);
+#endif
+
+    if (!compute_master_secret(bytes)) {
+        dbgln("oh noes we could not derive a master key :(");
+        return;
+    }
+
+    builder.append_u24(outbuf.size() + 2);
+    builder.append((u16)outbuf.size());
+    builder.append(outbuf);
+}
+
+ssize_t TLSv12::handle_payload(ReadonlyBytes vbuffer)
+{
+    if (m_context.connection_status == ConnectionStatus::Established) {
+#ifdef TLS_DEBUG
+        dbgln("Renegotiation attempt ignored");
+#endif
+        // FIXME: We should properly say "NoRenegotiation", but that causes a handshake failure
+        //        so we just roll with it and pretend that we _did_ renegotiate
+        //        This will cause issues when we decide to have long-lasting connections, but
+        //        we do not have those at the moment :^)
+        return 1;
+    }
+    auto buffer = vbuffer;
+    auto buffer_length = buffer.size();
+    auto original_length = buffer_length;
+    while (buffer_length >= 4 && !m_context.critical_error) {
+        ssize_t payload_res = 0;
+        if (buffer_length < 1)
+            return (i8)Error::NeedMoreData;
+        auto type = buffer[0];
+        auto write_packets { WritePacketStage::Initial };
+        size_t payload_size = buffer[1] * 0x10000 + buffer[2] * 0x100 + buffer[3] + 3;
+#ifdef TLS_DEBUG
+        dbg() << "payload size: " << payload_size << " buffer length: " << buffer_length;
+#endif
+        if (payload_size + 1 > buffer_length)
+            return (i8)Error::NeedMoreData;
+
+        switch (type) {
+        case HelloRequest:
+            if (m_context.handshake_messages[0] >= 1) {
+                dbgln("unexpected hello request message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[0];
+            dbgln("hello request (renegotiation?)");
+            if (m_context.connection_status == ConnectionStatus::Established) {
+                // renegotiation
+                payload_res = (i8)Error::NoRenegotiation;
+            } else {
+                // :shrug:
+                payload_res = (i8)Error::UnexpectedMessage;
+            }
+            break;
+        case ClientHello:
+            // FIXME: We only support client mode right now
+            if (m_context.is_server) {
+                ASSERT_NOT_REACHED();
+            }
+            payload_res = (i8)Error::UnexpectedMessage;
+            break;
+        case ServerHello:
+            if (m_context.handshake_messages[2] >= 1) {
+                dbgln("unexpected server hello message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[2];
+#ifdef TLS_DEBUG
+            dbgln("server hello");
+#endif
+            if (m_context.is_server) {
+                dbgln("unsupported: server mode");
+                ASSERT_NOT_REACHED();
+            } else {
+                payload_res = handle_hello(buffer.slice(1, payload_size), write_packets);
+            }
+            break;
+        case HelloVerifyRequest:
+            dbgln("unsupported: DTLS");
+            payload_res = (i8)Error::UnexpectedMessage;
+            break;
+        case CertificateMessage:
+            if (m_context.handshake_messages[4] >= 1) {
+                dbgln("unexpected certificate message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[4];
+#ifdef TLS_DEBUG
+            dbgln("certificate");
+#endif
+            if (m_context.connection_status == ConnectionStatus::Negotiating) {
+                if (m_context.is_server) {
+                    dbgln("unsupported: server mode");
+                    ASSERT_NOT_REACHED();
+                }
+                payload_res = handle_certificate(buffer.slice(1, payload_size));
+                if (m_context.certificates.size()) {
+                    auto it = m_context.certificates.find_if([](const auto& cert) { return cert.is_valid(); });
+
+                    if (it.is_end()) {
+                        // no valid certificates
+                        dbgln("No valid certificates found");
+                        payload_res = (i8)Error::BadCertificate;
+                        m_context.critical_error = payload_res;
+                        break;
+                    }
+
+                    // swap the first certificate with the valid one
+                    if (it.index() != 0)
+                        swap(m_context.certificates[0], m_context.certificates[it.index()]);
+                }
+            } else {
+                payload_res = (i8)Error::UnexpectedMessage;
+            }
+            break;
+        case ServerKeyExchange:
+            if (m_context.handshake_messages[5] >= 1) {
+                dbgln("unexpected server key exchange message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[5];
+#ifdef TLS_DEBUG
+            dbgln("server key exchange");
+#endif
+            if (m_context.is_server) {
+                dbgln("unsupported: server mode");
+                ASSERT_NOT_REACHED();
+            } else {
+                payload_res = handle_server_key_exchange(buffer.slice(1, payload_size));
+            }
+            break;
+        case CertificateRequest:
+            if (m_context.handshake_messages[6] >= 1) {
+                dbgln("unexpected certificate request message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[6];
+            if (m_context.is_server) {
+                dbgln("invalid request");
+                dbgln("unsupported: server mode");
+                ASSERT_NOT_REACHED();
+            } else {
+                // we do not support "certificate request"
+                dbgln("certificate request");
+                if (on_tls_certificate_request)
+                    on_tls_certificate_request(*this);
+                m_context.client_verified = VerificationNeeded;
+            }
+            break;
+        case ServerHelloDone:
+            if (m_context.handshake_messages[7] >= 1) {
+                dbgln("unexpected server hello done message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[7];
+#ifdef TLS_DEBUG
+            dbgln("server hello done");
+#endif
+            if (m_context.is_server) {
+                dbgln("unsupported: server mode");
+                ASSERT_NOT_REACHED();
+            } else {
+                payload_res = handle_server_hello_done(buffer.slice(1, payload_size));
+                if (payload_res > 0)
+                    write_packets = WritePacketStage::ClientHandshake;
+            }
+            break;
+        case CertificateVerify:
+            if (m_context.handshake_messages[8] >= 1) {
+                dbgln("unexpected certificate verify message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[8];
+#ifdef TLS_DEBUG
+            dbgln("certificate verify");
+#endif
+            if (m_context.connection_status == ConnectionStatus::KeyExchange) {
+                payload_res = handle_verify(buffer.slice(1, payload_size));
+            } else {
+                payload_res = (i8)Error::UnexpectedMessage;
+            }
+            break;
+        case ClientKeyExchange:
+            if (m_context.handshake_messages[9] >= 1) {
+                dbgln("unexpected client key exchange message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[9];
+#ifdef TLS_DEBUG
+            dbgln("client key exchange");
+#endif
+            if (m_context.is_server) {
+                dbgln("unsupported: server mode");
+                ASSERT_NOT_REACHED();
+            } else {
+                payload_res = (i8)Error::UnexpectedMessage;
+            }
+            break;
+        case Finished:
+            if (m_context.cached_handshake) {
+                m_context.cached_handshake.clear();
+            }
+            if (m_context.handshake_messages[10] >= 1) {
+                dbgln("unexpected finished message");
+                payload_res = (i8)Error::UnexpectedMessage;
+                break;
+            }
+            ++m_context.handshake_messages[10];
+#ifdef TLS_DEBUG
+            dbgln("finished");
+#endif
+            payload_res = handle_finished(buffer.slice(1, payload_size), write_packets);
+            if (payload_res > 0) {
+                memset(m_context.handshake_messages, 0, sizeof(m_context.handshake_messages));
+            }
+            break;
+        default:
+            dbg() << "message type not understood: " << type;
+            return (i8)Error::NotUnderstood;
+        }
+
+        if (type != HelloRequest) {
+            update_hash(buffer.slice(0, payload_size + 1));
+        }
+
+        // if something went wrong, send an alert about it
+        if (payload_res < 0) {
+            switch ((Error)payload_res) {
+            case Error::UnexpectedMessage: {
+                auto packet = build_alert(true, (u8)AlertDescription::UnexpectedMessage);
+                write_packet(packet);
+                break;
+            }
+            case Error::CompressionNotSupported: {
+                auto packet = build_alert(true, (u8)AlertDescription::DecompressionFailure);
+                write_packet(packet);
+                break;
+            }
+            case Error::BrokenPacket: {
+                auto packet = build_alert(true, (u8)AlertDescription::DecodeError);
+                write_packet(packet);
+                break;
+            }
+            case Error::NotVerified: {
+                auto packet = build_alert(true, (u8)AlertDescription::BadRecordMAC);
+                write_packet(packet);
+                break;
+            }
+            case Error::BadCertificate: {
+                auto packet = build_alert(true, (u8)AlertDescription::BadCertificate);
+                write_packet(packet);
+                break;
+            }
+            case Error::UnsupportedCertificate: {
+                auto packet = build_alert(true, (u8)AlertDescription::UnsupportedCertificate);
+                write_packet(packet);
+                break;
+            }
+            case Error::NoCommonCipher: {
+                auto packet = build_alert(true, (u8)AlertDescription::InsufficientSecurity);
+                write_packet(packet);
+                break;
+            }
+            case Error::NotUnderstood: {
+                auto packet = build_alert(true, (u8)AlertDescription::InternalError);
+                write_packet(packet);
+                break;
+            }
+            case Error::NoRenegotiation: {
+                auto packet = build_alert(true, (u8)AlertDescription::NoRenegotiation);
+                write_packet(packet);
+                break;
+            }
+            case Error::DecryptionFailed: {
+                auto packet = build_alert(true, (u8)AlertDescription::DecryptionFailed);
+                write_packet(packet);
+                break;
+            }
+            case Error::NeedMoreData:
+                // Ignore this, as it's not an "error"
+                break;
+            default:
+                dbg() << "Unknown TLS::Error with value " << payload_res;
+                ASSERT_NOT_REACHED();
+                break;
+            }
+            if (payload_res < 0)
+                return payload_res;
+        }
+        switch (write_packets) {
+        case WritePacketStage::Initial:
+            // nothing to write
+            break;
+        case WritePacketStage::ClientHandshake:
+            if (m_context.client_verified == VerificationNeeded) {
+#ifdef TLS_DEBUG
+                dbgln("> Client Certificate");
+#endif
+                auto packet = build_certificate();
+                write_packet(packet);
+                m_context.client_verified = Verified;
+            }
+            {
+#ifdef TLS_DEBUG
+                dbgln("> Key exchange");
+#endif
+                auto packet = build_client_key_exchange();
+                write_packet(packet);
+            }
+            {
+#ifdef TLS_DEBUG
+                dbgln("> change cipher spec");
+#endif
+                auto packet = build_change_cipher_spec();
+                write_packet(packet);
+            }
+            m_context.cipher_spec_set = 1;
+            m_context.local_sequence_number = 0;
+            {
+#ifdef TLS_DEBUG
+                dbgln("> client finished");
+#endif
+                auto packet = build_finished();
+                write_packet(packet);
+            }
+            m_context.cipher_spec_set = 0;
+            break;
+        case WritePacketStage::ServerHandshake:
+            // server handshake
+            dbgln("UNSUPPORTED: Server mode");
+            ASSERT_NOT_REACHED();
+            break;
+        case WritePacketStage::Finished:
+            // finished
+            {
+#ifdef TLS_DEBUG
+                dbgln("> change cipher spec");
+#endif
+                auto packet = build_change_cipher_spec();
+                write_packet(packet);
+            }
+            {
+#ifdef TLS_DEBUG
+                dbgln("> client finished");
+#endif
+                auto packet = build_finished();
+                write_packet(packet);
+            }
+            m_context.connection_status = ConnectionStatus::Established;
+            break;
+        }
+        payload_size++;
+        buffer_length -= payload_size;
+        buffer = buffer.slice(payload_size, buffer_length);
+    }
+    return original_length;
+}
+
+}

Userland/Libraries/LibTLS/Exchange.cpp

@@ -0,0 +1,280 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/PK/Code/EMSA_PSS.h>
+#include <LibTLS/TLSv12.h>
+
+namespace TLS {
+
+bool TLSv12::expand_key()
+{
+    u8 key[192]; // soooooooo many constants
+    auto key_buffer = Bytes { key, sizeof(key) };
+
+    auto is_aead = this->is_aead();
+
+    if (m_context.master_key.size() == 0) {
+        dbgln("expand_key() with empty master key");
+        return false;
+    }
+
+    auto key_size = key_length();
+    auto mac_size = mac_length();
+    auto iv_size = iv_length();
+
+    pseudorandom_function(
+        key_buffer,
+        m_context.master_key,
+        (const u8*)"key expansion", 13,
+        ReadonlyBytes { m_context.remote_random, sizeof(m_context.remote_random) },
+        ReadonlyBytes { m_context.local_random, sizeof(m_context.local_random) });
+
+    size_t offset = 0;
+    if (is_aead) {
+        iv_size = 4; // Explicit IV size.
+    } else {
+        memcpy(m_context.crypto.local_mac, key + offset, mac_size);
+        offset += mac_size;
+        memcpy(m_context.crypto.remote_mac, key + offset, mac_size);
+        offset += mac_size;
+    }
+
+    auto client_key = key + offset;
+    offset += key_size;
+    auto server_key = key + offset;
+    offset += key_size;
+    auto client_iv = key + offset;
+    offset += iv_size;
+    auto server_iv = key + offset;
+    offset += iv_size;
+
+#ifdef TLS_DEBUG
+    dbgln("client key");
+    print_buffer(client_key, key_size);
+    dbgln("server key");
+    print_buffer(server_key, key_size);
+    dbgln("client iv");
+    print_buffer(client_iv, iv_size);
+    dbgln("server iv");
+    print_buffer(server_iv, iv_size);
+    if (!is_aead) {
+        dbgln("client mac key");
+        print_buffer(m_context.crypto.local_mac, mac_size);
+        dbgln("server mac key");
+        print_buffer(m_context.crypto.remote_mac, mac_size);
+    }
+#endif
+
+    if (is_aead) {
+        memcpy(m_context.crypto.local_aead_iv, client_iv, iv_size);
+        memcpy(m_context.crypto.remote_aead_iv, server_iv, iv_size);
+
+        m_aes_local.gcm = make<Crypto::Cipher::AESCipher::GCMMode>(ReadonlyBytes { client_key, key_size }, key_size * 8, Crypto::Cipher::Intent::Encryption, Crypto::Cipher::PaddingMode::RFC5246);
+        m_aes_remote.gcm = make<Crypto::Cipher::AESCipher::GCMMode>(ReadonlyBytes { server_key, key_size }, key_size * 8, Crypto::Cipher::Intent::Decryption, Crypto::Cipher::PaddingMode::RFC5246);
+    } else {
+        memcpy(m_context.crypto.local_iv, client_iv, iv_size);
+        memcpy(m_context.crypto.remote_iv, server_iv, iv_size);
+
+        m_aes_local.cbc = make<Crypto::Cipher::AESCipher::CBCMode>(ReadonlyBytes { client_key, key_size }, key_size * 8, Crypto::Cipher::Intent::Encryption, Crypto::Cipher::PaddingMode::RFC5246);
+        m_aes_remote.cbc = make<Crypto::Cipher::AESCipher::CBCMode>(ReadonlyBytes { server_key, key_size }, key_size * 8, Crypto::Cipher::Intent::Decryption, Crypto::Cipher::PaddingMode::RFC5246);
+    }
+
+    m_context.crypto.created = 1;
+
+    return true;
+}
+
+void TLSv12::pseudorandom_function(Bytes output, ReadonlyBytes secret, const u8* label, size_t label_length, ReadonlyBytes seed, ReadonlyBytes seed_b)
+{
+    if (!secret.size()) {
+        dbgln("null secret");
+        return;
+    }
+
+    // RFC 5246: "In this section, we define one PRF, based on HMAC.  This PRF with the
+    //            SHA-256 hash function is used for all cipher suites defined in this
+    //            document and in TLS documents published prior to this document when
+    //            TLS 1.2 is negotiated."
+    // Apparently this PRF _always_ uses SHA256
+    Crypto::Authentication::HMAC<Crypto::Hash::SHA256> hmac(secret);
+
+    auto l_seed_size = label_length + seed.size() + seed_b.size();
+    u8 l_seed[l_seed_size];
+    auto label_seed_buffer = Bytes { l_seed, l_seed_size };
+    label_seed_buffer.overwrite(0, label, label_length);
+    label_seed_buffer.overwrite(label_length, seed.data(), seed.size());
+    label_seed_buffer.overwrite(label_length + seed.size(), seed_b.data(), seed_b.size());
+
+    auto digest_size = hmac.digest_size();
+
+    u8 digest[digest_size];
+
+    auto digest_0 = Bytes { digest, digest_size };
+
+    digest_0.overwrite(0, hmac.process(label_seed_buffer).immutable_data(), digest_size);
+
+    size_t index = 0;
+    while (index < output.size()) {
+        hmac.update(digest_0);
+        hmac.update(label_seed_buffer);
+        auto digest_1 = hmac.digest();
+
+        auto copy_size = min(digest_size, output.size() - index);
+
+        output.overwrite(index, digest_1.immutable_data(), copy_size);
+        index += copy_size;
+
+        digest_0.overwrite(0, hmac.process(digest_0).immutable_data(), digest_size);
+    }
+}
+
+bool TLSv12::compute_master_secret(size_t length)
+{
+    if (m_context.premaster_key.size() == 0 || length < 48) {
+        dbgln("there's no way I can make a master secret like this");
+        dbg() << "I'd like to talk to your manager about this length of " << length;
+        return false;
+    }
+
+    m_context.master_key.clear();
+    m_context.master_key.grow(length);
+
+    pseudorandom_function(
+        m_context.master_key,
+        m_context.premaster_key,
+        (const u8*)"master secret", 13,
+        ReadonlyBytes { m_context.local_random, sizeof(m_context.local_random) },
+        ReadonlyBytes { m_context.remote_random, sizeof(m_context.remote_random) });
+
+    m_context.premaster_key.clear();
+#ifdef TLS_DEBUG
+    dbgln("master key:");
+    print_buffer(m_context.master_key);
+#endif
+    expand_key();
+    return true;
+}
+
+ByteBuffer TLSv12::build_certificate()
+{
+    PacketBuilder builder { MessageType::Handshake, m_context.version };
+
+    Vector<const Certificate*> certificates;
+    Vector<Certificate>* local_certificates = nullptr;
+
+    if (m_context.is_server) {
+        dbgln("Unsupported: Server mode");
+        ASSERT_NOT_REACHED();
+    } else {
+        local_certificates = &m_context.client_certificates;
+    }
+
+    constexpr size_t der_length_delta = 3;
+    constexpr size_t certificate_vector_header_size = 3;
+
+    size_t total_certificate_size = 0;
+
+    for (size_t i = 0; i < local_certificates->size(); ++i) {
+        auto& certificate = local_certificates->at(i);
+        if (!certificate.der.is_empty()) {
+            total_certificate_size += certificate.der.size() + der_length_delta;
+
+            // FIXME: Check for and respond with only the requested certificate types.
+            if (true) {
+                certificates.append(&certificate);
+            }
+        }
+    }
+
+    builder.append((u8)HandshakeType::CertificateMessage);
+
+    if (!total_certificate_size) {
+#ifdef TLS_DEBUG
+        dbgln("No certificates, sending empty certificate message");
+#endif
+        builder.append_u24(certificate_vector_header_size);
+        builder.append_u24(total_certificate_size);
+    } else {
+        builder.append_u24(total_certificate_size + certificate_vector_header_size); // 3 bytes for header
+        builder.append_u24(total_certificate_size);
+
+        for (auto& certificate : certificates) {
+            if (!certificate->der.is_empty()) {
+                builder.append_u24(certificate->der.size());
+                builder.append(certificate->der.bytes());
+            }
+        }
+    }
+    auto packet = builder.build();
+    update_packet(packet);
+    return packet;
+}
+
+ByteBuffer TLSv12::build_change_cipher_spec()
+{
+    PacketBuilder builder { MessageType::ChangeCipher, m_context.version, 64 };
+    builder.append((u8)1);
+    auto packet = builder.build();
+    update_packet(packet);
+    m_context.local_sequence_number = 0;
+    return packet;
+}
+
+ByteBuffer TLSv12::build_server_key_exchange()
+{
+    dbgln("FIXME: build_server_key_exchange");
+    return {};
+}
+
+ByteBuffer TLSv12::build_client_key_exchange()
+{
+    PacketBuilder builder { MessageType::Handshake, m_context.version };
+    builder.append((u8)HandshakeType::ClientKeyExchange);
+    build_random(builder);
+
+    m_context.connection_status = ConnectionStatus::KeyExchange;
+
+    auto packet = builder.build();
+
+    update_packet(packet);
+
+    return packet;
+}
+
+ssize_t TLSv12::handle_server_key_exchange(ReadonlyBytes)
+{
+    dbgln("FIXME: parse_server_key_exchange");
+    return 0;
+}
+
+ssize_t TLSv12::handle_verify(ReadonlyBytes)
+{
+    dbgln("FIXME: parse_verify");
+    return 0;
+}
+
+}

Userland/Libraries/LibTLS/Handshake.cpp

@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Random.h>
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/PK/Code/EMSA_PSS.h>
+#include <LibTLS/TLSv12.h>
+
+namespace TLS {
+
+ByteBuffer TLSv12::build_hello()
+{
+    AK::fill_with_random(&m_context.local_random, 32);
+
+    auto packet_version = (u16)m_context.version;
+    auto version = (u16)m_context.version;
+    PacketBuilder builder { MessageType::Handshake, packet_version };
+
+    builder.append((u8)ClientHello);
+
+    // hello length (for later)
+    u8 dummy[3] = {};
+    builder.append(dummy, 3);
+
+    auto start_length = builder.length();
+
+    builder.append(version);
+    builder.append(m_context.local_random, sizeof(m_context.local_random));
+
+    builder.append(m_context.session_id_size);
+    if (m_context.session_id_size)
+        builder.append(m_context.session_id, m_context.session_id_size);
+
+    size_t extension_length = 0;
+    size_t alpn_length = 0;
+    size_t alpn_negotiated_length = 0;
+
+    // ALPN
+    if (!m_context.negotiated_alpn.is_null()) {
+        alpn_negotiated_length = m_context.negotiated_alpn.length();
+        alpn_length = alpn_negotiated_length + 1;
+        extension_length += alpn_length + 6;
+    } else if (m_context.alpn.size()) {
+        for (auto& alpn : m_context.alpn) {
+            size_t length = alpn.length();
+            alpn_length += length + 1;
+        }
+        if (alpn_length)
+            extension_length += alpn_length + 6;
+    }
+
+    // Ciphers
+    builder.append((u16)(5 * sizeof(u16)));
+    builder.append((u16)CipherSuite::RSA_WITH_AES_128_CBC_SHA256);
+    builder.append((u16)CipherSuite::RSA_WITH_AES_256_CBC_SHA256);
+    builder.append((u16)CipherSuite::RSA_WITH_AES_128_CBC_SHA);
+    builder.append((u16)CipherSuite::RSA_WITH_AES_256_CBC_SHA);
+    builder.append((u16)CipherSuite::RSA_WITH_AES_128_GCM_SHA256);
+
+    // we don't like compression
+    builder.append((u8)1);
+    builder.append((u8)0);
+
+    // set SNI if we have one
+    auto sni_length = 0;
+    if (!m_context.SNI.is_null())
+        sni_length = m_context.SNI.length();
+
+    if (sni_length)
+        extension_length += sni_length + 9;
+
+    builder.append((u16)extension_length);
+
+    if (sni_length) {
+        // SNI extension
+        builder.append((u16)HandshakeExtension::ServerName);
+        // extension length
+        builder.append((u16)(sni_length + 5));
+        // SNI length
+        builder.append((u16)(sni_length + 3));
+        // SNI type
+        builder.append((u8)0);
+        // SNI host length + value
+        builder.append((u16)sni_length);
+        builder.append((const u8*)m_context.SNI.characters(), sni_length);
+    }
+
+    if (alpn_length) {
+        // TODO
+        ASSERT_NOT_REACHED();
+    }
+
+    // set the "length" field of the packet
+    size_t remaining = builder.length() - start_length;
+    size_t payload_position = 6;
+    builder.set(payload_position, remaining / 0x10000);
+    remaining %= 0x10000;
+    builder.set(payload_position + 1, remaining / 0x100);
+    remaining %= 0x100;
+    builder.set(payload_position + 2, remaining);
+
+    auto packet = builder.build();
+    update_packet(packet);
+
+    return packet;
+}
+
+ByteBuffer TLSv12::build_alert(bool critical, u8 code)
+{
+    PacketBuilder builder(MessageType::Alert, (u16)m_context.version);
+    builder.append((u8)(critical ? AlertLevel::Critical : AlertLevel::Warning));
+    builder.append(code);
+
+    if (critical)
+        m_context.critical_error = code;
+
+    auto packet = builder.build();
+    update_packet(packet);
+
+    return packet;
+}
+
+ByteBuffer TLSv12::build_finished()
+{
+    PacketBuilder builder { MessageType::Handshake, m_context.version, 12 + 64 };
+    builder.append((u8)HandshakeType::Finished);
+
+    u32 out_size = 12;
+
+    builder.append_u24(out_size);
+
+    u8 out[out_size];
+    auto outbuffer = Bytes { out, out_size };
+    auto dummy = ByteBuffer::create_zeroed(0);
+
+    auto digest = m_context.handshake_hash.digest();
+    auto hashbuf = ReadonlyBytes { digest.immutable_data(), m_context.handshake_hash.digest_size() };
+    pseudorandom_function(outbuffer, m_context.master_key, (const u8*)"client finished", 15, hashbuf, dummy);
+
+    builder.append(outbuffer);
+    auto packet = builder.build();
+    update_packet(packet);
+
+    return packet;
+}
+
+void TLSv12::alert(AlertLevel level, AlertDescription code)
+{
+    auto the_alert = build_alert(level == AlertLevel::Critical, (u8)code);
+    write_packet(the_alert);
+    flush();
+}
+
+}

Userland/Libraries/LibTLS/Record.cpp

@@ -0,0 +1,472 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Endian.h>
+
+#include <AK/MemoryStream.h>
+#include <LibCore/Timer.h>
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/PK/Code/EMSA_PSS.h>
+#include <LibTLS/TLSv12.h>
+
+namespace TLS {
+
+void TLSv12::write_packet(ByteBuffer& packet)
+{
+    m_context.tls_buffer.append(packet.data(), packet.size());
+    if (m_context.connection_status > ConnectionStatus::Disconnected) {
+        if (!m_has_scheduled_write_flush) {
+#ifdef TLS_DEBUG
+            dbg() << "Scheduling write of " << m_context.tls_buffer.size();
+#endif
+            deferred_invoke([this](auto&) { write_into_socket(); });
+            m_has_scheduled_write_flush = true;
+        } else {
+            // multiple packet are available, let's flush some out
+#ifdef TLS_DEBUG
+            dbg() << "Flushing scheduled write of " << m_context.tls_buffer.size();
+#endif
+            write_into_socket();
+            // the deferred invoke is still in place
+            m_has_scheduled_write_flush = true;
+        }
+    }
+}
+
+void TLSv12::update_packet(ByteBuffer& packet)
+{
+    u32 header_size = 5;
+    *(u16*)packet.offset_pointer(3) = AK::convert_between_host_and_network_endian((u16)(packet.size() - header_size));
+
+    if (packet[0] != (u8)MessageType::ChangeCipher) {
+        if (packet[0] == (u8)MessageType::Handshake && packet.size() > header_size) {
+            u8 handshake_type = packet[header_size];
+            if (handshake_type != HandshakeType::HelloRequest && handshake_type != HandshakeType::HelloVerifyRequest) {
+                update_hash(packet.bytes().slice(header_size, packet.size() - header_size));
+            }
+        }
+        if (m_context.cipher_spec_set && m_context.crypto.created) {
+            size_t length = packet.size() - header_size;
+            size_t block_size, padding, mac_size;
+
+            if (!is_aead()) {
+                block_size = m_aes_local.cbc->cipher().block_size();
+                // If the length is already a multiple a block_size,
+                // an entire block of padding is added.
+                // In short, we _never_ have no padding.
+                mac_size = mac_length();
+                length += mac_size;
+                padding = block_size - length % block_size;
+                length += padding;
+            } else {
+                block_size = m_aes_local.gcm->cipher().block_size();
+                padding = 0;
+                mac_size = 0; // AEAD provides its own authentication scheme.
+            }
+
+            if (m_context.crypto.created == 1) {
+                // `buffer' will continue to be encrypted
+                auto buffer = ByteBuffer::create_uninitialized(length);
+                size_t buffer_position = 0;
+                auto iv_size = iv_length();
+
+                // copy the packet, sans the header
+                buffer.overwrite(buffer_position, packet.offset_pointer(header_size), packet.size() - header_size);
+                buffer_position += packet.size() - header_size;
+
+                ByteBuffer ct;
+
+                if (is_aead()) {
+                    // We need enough space for a header, the data, a tag, and the IV
+                    ct = ByteBuffer::create_uninitialized(length + header_size + iv_size + 16);
+
+                    // copy the header over
+                    ct.overwrite(0, packet.data(), header_size - 2);
+
+                    // AEAD AAD (13)
+                    // Seq. no (8)
+                    // content type (1)
+                    // version (2)
+                    // length (2)
+                    u8 aad[13];
+                    Bytes aad_bytes { aad, 13 };
+                    OutputMemoryStream aad_stream { aad_bytes };
+
+                    u64 seq_no = AK::convert_between_host_and_network_endian(m_context.local_sequence_number);
+                    u16 len = AK::convert_between_host_and_network_endian((u16)(packet.size() - header_size));
+
+                    aad_stream.write({ &seq_no, sizeof(seq_no) });
+                    aad_stream.write(packet.bytes().slice(0, 3)); // content-type + version
+                    aad_stream.write({ &len, sizeof(len) });      // length
+                    ASSERT(aad_stream.is_end());
+
+                    // AEAD IV (12)
+                    // IV (4)
+                    // (Nonce) (8)
+                    // -- Our GCM impl takes 16 bytes
+                    // zero (4)
+                    u8 iv[16];
+                    Bytes iv_bytes { iv, 16 };
+                    Bytes { m_context.crypto.local_aead_iv, 4 }.copy_to(iv_bytes);
+                    AK::fill_with_random(iv_bytes.offset(4), 8);
+                    memset(iv_bytes.offset(12), 0, 4);
+
+                    // write the random part of the iv out
+                    iv_bytes.slice(4, 8).copy_to(ct.bytes().slice(header_size));
+
+                    // Write the encrypted data and the tag
+                    m_aes_local.gcm->encrypt(
+                        packet.bytes().slice(header_size, length),
+                        ct.bytes().slice(header_size + 8, length),
+                        iv_bytes,
+                        aad_bytes,
+                        ct.bytes().slice(header_size + 8 + length, 16));
+
+                    ASSERT(header_size + 8 + length + 16 == ct.size());
+
+                } else {
+                    // We need enough space for a header, iv_length bytes of IV and whatever the packet contains
+                    ct = ByteBuffer::create_uninitialized(length + header_size + iv_size);
+
+                    // copy the header over
+                    ct.overwrite(0, packet.data(), header_size - 2);
+
+                    // get the appropricate HMAC value for the entire packet
+                    auto mac = hmac_message(packet, {}, mac_size, true);
+
+                    // write the MAC
+                    buffer.overwrite(buffer_position, mac.data(), mac.size());
+                    buffer_position += mac.size();
+
+                    // Apply the padding (a packet MUST always be padded)
+                    memset(buffer.offset_pointer(buffer_position), padding - 1, padding);
+                    buffer_position += padding;
+
+                    ASSERT(buffer_position == buffer.size());
+
+                    auto iv = ByteBuffer::create_uninitialized(iv_size);
+                    AK::fill_with_random(iv.data(), iv.size());
+
+                    // write it into the ciphertext portion of the message
+                    ct.overwrite(header_size, iv.data(), iv.size());
+
+                    ASSERT(header_size + iv_size + length == ct.size());
+                    ASSERT(length % block_size == 0);
+
+                    // get a block to encrypt into
+                    auto view = ct.bytes().slice(header_size + iv_size, length);
+                    m_aes_local.cbc->encrypt(buffer, view, iv);
+                }
+
+                // store the correct ciphertext length into the packet
+                u16 ct_length = (u16)ct.size() - header_size;
+
+                *(u16*)ct.offset_pointer(header_size - 2) = AK::convert_between_host_and_network_endian(ct_length);
+
+                // replace the packet with the ciphertext
+                packet = ct;
+            }
+        }
+    }
+    ++m_context.local_sequence_number;
+}
+
+void TLSv12::update_hash(ReadonlyBytes message)
+{
+    m_context.handshake_hash.update(message);
+}
+
+ByteBuffer TLSv12::hmac_message(const ReadonlyBytes& buf, const Optional<ReadonlyBytes> buf2, size_t mac_length, bool local)
+{
+    u64 sequence_number = AK::convert_between_host_and_network_endian(local ? m_context.local_sequence_number : m_context.remote_sequence_number);
+    ensure_hmac(mac_length, local);
+    auto& hmac = local ? *m_hmac_local : *m_hmac_remote;
+#ifdef TLS_DEBUG
+    dbgln("========================= PACKET DATA ==========================");
+    print_buffer((const u8*)&sequence_number, sizeof(u64));
+    print_buffer(buf.data(), buf.size());
+    if (buf2.has_value())
+        print_buffer(buf2.value().data(), buf2.value().size());
+    dbgln("========================= PACKET DATA ==========================");
+#endif
+    hmac.update((const u8*)&sequence_number, sizeof(u64));
+    hmac.update(buf);
+    if (buf2.has_value() && buf2.value().size()) {
+        hmac.update(buf2.value());
+    }
+    auto digest = hmac.digest();
+    auto mac = ByteBuffer::copy(digest.immutable_data(), digest.data_length());
+#ifdef TLS_DEBUG
+    dbg() << "HMAC of the block for sequence number " << sequence_number;
+    print_buffer(mac);
+#endif
+    return mac;
+}
+
+ssize_t TLSv12::handle_message(ReadonlyBytes buffer)
+{
+    auto res { 5ll };
+    size_t header_size = res;
+    ssize_t payload_res = 0;
+
+#ifdef TLS_DEBUG
+    dbg() << "buffer size: " << buffer.size();
+#endif
+    if (buffer.size() < 5) {
+        return (i8)Error::NeedMoreData;
+    }
+
+    auto type = (MessageType)buffer[0];
+    size_t buffer_position { 1 };
+
+    // FIXME: Read the version and verify it
+#ifdef TLS_DEBUG
+    auto version = (Version) * (const u16*)buffer.offset_pointer(buffer_position);
+    dbg() << "type: " << (u8)type << " version: " << (u16)version;
+#endif
+    buffer_position += 2;
+
+    auto length = AK::convert_between_host_and_network_endian(*(const u16*)buffer.offset_pointer(buffer_position));
+#ifdef TLS_DEBUG
+    dbg() << "record length: " << length << " at offset: " << buffer_position;
+#endif
+    buffer_position += 2;
+
+    if (buffer_position + length > buffer.size()) {
+#ifdef TLS_DEBUG
+        dbg() << "record length more than what we have: " << buffer.size();
+#endif
+        return (i8)Error::NeedMoreData;
+    }
+
+#ifdef TLS_DEBUG
+    dbg() << "message type: " << (u8)type << ", length: " << length;
+#endif
+    auto plain = buffer.slice(buffer_position, buffer.size() - buffer_position);
+
+    ByteBuffer decrypted;
+
+    if (m_context.cipher_spec_set && type != MessageType::ChangeCipher) {
+#ifdef TLS_DEBUG
+        dbgln("Encrypted: ");
+        print_buffer(buffer.slice(header_size, length));
+#endif
+
+        if (is_aead()) {
+            ASSERT(m_aes_remote.gcm);
+
+            if (length < 24) {
+                dbgln("Invalid packet length");
+                auto packet = build_alert(true, (u8)AlertDescription::DecryptError);
+                write_packet(packet);
+                return (i8)Error::BrokenPacket;
+            }
+
+            auto packet_length = length - iv_length() - 16;
+            auto payload = plain;
+            decrypted = ByteBuffer::create_uninitialized(packet_length);
+
+            // AEAD AAD (13)
+            // Seq. no (8)
+            // content type (1)
+            // version (2)
+            // length (2)
+            u8 aad[13];
+            Bytes aad_bytes { aad, 13 };
+            OutputMemoryStream aad_stream { aad_bytes };
+
+            u64 seq_no = AK::convert_between_host_and_network_endian(m_context.remote_sequence_number);
+            u16 len = AK::convert_between_host_and_network_endian((u16)packet_length);
+
+            aad_stream.write({ &seq_no, sizeof(seq_no) });      // Sequence number
+            aad_stream.write(buffer.slice(0, header_size - 2)); // content-type + version
+            aad_stream.write({ &len, sizeof(u16) });
+            ASSERT(aad_stream.is_end());
+
+            auto nonce = payload.slice(0, iv_length());
+            payload = payload.slice(iv_length());
+
+            // AEAD IV (12)
+            // IV (4)
+            // (Nonce) (8)
+            // -- Our GCM impl takes 16 bytes
+            // zero (4)
+            u8 iv[16];
+            Bytes iv_bytes { iv, 16 };
+            Bytes { m_context.crypto.remote_aead_iv, 4 }.copy_to(iv_bytes);
+            nonce.copy_to(iv_bytes.slice(4));
+            memset(iv_bytes.offset(12), 0, 4);
+
+            auto ciphertext = payload.slice(0, payload.size() - 16);
+            auto tag = payload.slice(ciphertext.size());
+
+            auto consistency = m_aes_remote.gcm->decrypt(
+                ciphertext,
+                decrypted,
+                iv_bytes,
+                aad_bytes,
+                tag);
+
+            if (consistency != Crypto::VerificationConsistency::Consistent) {
+                dbg() << "integrity check failed (tag length " << tag.size() << ")";
+                auto packet = build_alert(true, (u8)AlertDescription::BadRecordMAC);
+                write_packet(packet);
+
+                return (i8)Error::IntegrityCheckFailed;
+            }
+
+            plain = decrypted;
+        } else {
+            ASSERT(m_aes_remote.cbc);
+            auto iv_size = iv_length();
+
+            decrypted = m_aes_remote.cbc->create_aligned_buffer(length - iv_size);
+            auto iv = buffer.slice(header_size, iv_size);
+
+            Bytes decrypted_span = decrypted;
+            m_aes_remote.cbc->decrypt(buffer.slice(header_size + iv_size, length - iv_size), decrypted_span, iv);
+
+            length = decrypted_span.size();
+
+#ifdef TLS_DEBUG
+            dbgln("Decrypted: ");
+            print_buffer(decrypted);
+#endif
+
+            auto mac_size = mac_length();
+            if (length < mac_size) {
+                dbgln("broken packet");
+                auto packet = build_alert(true, (u8)AlertDescription::DecryptError);
+                write_packet(packet);
+                return (i8)Error::BrokenPacket;
+            }
+
+            length -= mac_size;
+
+            const u8* message_hmac = decrypted_span.offset(length);
+            u8 temp_buf[5];
+            memcpy(temp_buf, buffer.offset_pointer(0), 3);
+            *(u16*)(temp_buf + 3) = AK::convert_between_host_and_network_endian(length);
+            auto hmac = hmac_message({ temp_buf, 5 }, decrypted_span.slice(0, length), mac_size);
+            auto message_mac = ReadonlyBytes { message_hmac, mac_size };
+            if (hmac != message_mac) {
+                dbg() << "integrity check failed (mac length " << mac_size << ")";
+                dbgln("mac received:");
+                print_buffer(message_mac);
+                dbgln("mac computed:");
+                print_buffer(hmac);
+                auto packet = build_alert(true, (u8)AlertDescription::BadRecordMAC);
+                write_packet(packet);
+
+                return (i8)Error::IntegrityCheckFailed;
+            }
+            plain = decrypted.bytes().slice(0, length);
+        }
+    }
+    m_context.remote_sequence_number++;
+
+    switch (type) {
+    case MessageType::ApplicationData:
+        if (m_context.connection_status != ConnectionStatus::Established) {
+            dbgln("unexpected application data");
+            payload_res = (i8)Error::UnexpectedMessage;
+            auto packet = build_alert(true, (u8)AlertDescription::UnexpectedMessage);
+            write_packet(packet);
+        } else {
+#ifdef TLS_DEBUG
+            dbg() << "application data message of size " << plain.size();
+#endif
+
+            m_context.application_buffer.append(plain.data(), plain.size());
+        }
+        break;
+    case MessageType::Handshake:
+#ifdef TLS_DEBUG
+        dbgln("tls handshake message");
+#endif
+        payload_res = handle_payload(plain);
+        break;
+    case MessageType::ChangeCipher:
+        if (m_context.connection_status != ConnectionStatus::KeyExchange) {
+            dbgln("unexpected change cipher message");
+            auto packet = build_alert(true, (u8)AlertDescription::UnexpectedMessage);
+            payload_res = (i8)Error::UnexpectedMessage;
+        } else {
+#ifdef TLS_DEBUG
+            dbgln("change cipher spec message");
+#endif
+            m_context.cipher_spec_set = true;
+            m_context.remote_sequence_number = 0;
+        }
+        break;
+    case MessageType::Alert:
+#ifdef TLS_DEBUG
+        dbg() << "alert message of length " << length;
+#endif
+        if (length >= 2) {
+#ifdef TLS_DEBUG
+            print_buffer(plain);
+#endif
+            auto level = plain[0];
+            auto code = plain[1];
+            if (level == (u8)AlertLevel::Critical) {
+                dbg() << "We were alerted of a critical error: " << code << " (" << alert_name((AlertDescription)code) << ")";
+                m_context.critical_error = code;
+                try_disambiguate_error();
+                res = (i8)Error::UnknownError;
+            } else {
+                dbg() << "Alert: " << code;
+            }
+            if (code == 0) {
+                // close notify
+                res += 2;
+                alert(AlertLevel::Critical, AlertDescription::CloseNotify);
+                m_context.connection_finished = true;
+                if (!m_context.cipher_spec_set) {
+                    // AWS CloudFront hits this.
+                    dbgln("Server sent a close notify and we haven't agreed on a cipher suite. Treating it as a handshake failure.");
+                    m_context.critical_error = (u8)AlertDescription::HandshakeFailure;
+                    try_disambiguate_error();
+                }
+            }
+            m_context.error_code = (Error)code;
+        }
+        break;
+    default:
+        dbgln("message not understood");
+        return (i8)Error::NotUnderstood;
+    }
+
+    if (payload_res < 0)
+        return payload_res;
+
+    if (res > 0)
+        return header_size + length;
+
+    return res;
+}
+
+}

Userland/Libraries/LibTLS/Socket.cpp

@@ -0,0 +1,260 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibCore/DateTime.h>
+#include <LibCore/Timer.h>
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/PK/Code/EMSA_PSS.h>
+#include <LibTLS/TLSv12.h>
+
+namespace TLS {
+
+Optional<ByteBuffer> TLSv12::read()
+{
+    if (m_context.application_buffer.size()) {
+        auto buf = m_context.application_buffer.slice(0, m_context.application_buffer.size());
+        m_context.application_buffer.clear();
+        return buf;
+    }
+    return {};
+}
+
+ByteBuffer TLSv12::read(size_t max_size)
+{
+    if (m_context.application_buffer.size()) {
+        auto length = min(m_context.application_buffer.size(), max_size);
+        auto buf = m_context.application_buffer.slice(0, length);
+        m_context.application_buffer = m_context.application_buffer.slice(length, m_context.application_buffer.size() - length);
+        return buf;
+    }
+    return {};
+}
+
+String TLSv12::read_line(size_t max_size)
+{
+    if (!can_read_line())
+        return {};
+
+    auto* start = m_context.application_buffer.data();
+    auto* newline = (u8*)memchr(m_context.application_buffer.data(), '\n', m_context.application_buffer.size());
+    ASSERT(newline);
+
+    size_t offset = newline - start;
+
+    if (offset > max_size)
+        return {};
+
+    auto buffer = ByteBuffer::copy(start, offset);
+    m_context.application_buffer = m_context.application_buffer.slice(offset + 1, m_context.application_buffer.size() - offset - 1);
+
+    return String::copy(buffer, Chomp);
+}
+
+bool TLSv12::write(ReadonlyBytes buffer)
+{
+    if (m_context.connection_status != ConnectionStatus::Established) {
+#ifdef TLS_DEBUG
+        dbgln("write request while not connected");
+#endif
+        return false;
+    }
+
+    PacketBuilder builder { MessageType::ApplicationData, m_context.version, buffer.size() };
+    builder.append(buffer);
+    auto packet = builder.build();
+
+    update_packet(packet);
+    write_packet(packet);
+
+    return true;
+}
+
+bool TLSv12::connect(const String& hostname, int port)
+{
+    set_sni(hostname);
+    return Core::Socket::connect(hostname, port);
+}
+
+bool TLSv12::common_connect(const struct sockaddr* saddr, socklen_t length)
+{
+    if (m_context.critical_error)
+        return false;
+
+    if (Core::Socket::is_connected()) {
+        if (is_established()) {
+            ASSERT_NOT_REACHED();
+        } else {
+            Core::Socket::close(); // reuse?
+        }
+    }
+
+    Core::Socket::on_connected = [this] {
+        Core::Socket::on_ready_to_read = [this] {
+            read_from_socket();
+        };
+
+        auto packet = build_hello();
+        write_packet(packet);
+
+        deferred_invoke([&](auto&) {
+            m_handshake_timeout_timer = Core::Timer::create_single_shot(
+                m_max_wait_time_for_handshake_in_seconds * 1000, [&] {
+                    auto timeout_diff = Core::DateTime::now().timestamp() - m_context.handshake_initiation_timestamp;
+                    // If the timeout duration was actually within the max wait time (with a margin of error),
+                    // we're not operating slow, so the server timed out.
+                    // otherwise, it's our fault that the negotiation is taking too long, so extend the timer :P
+                    if (timeout_diff < m_max_wait_time_for_handshake_in_seconds + 1) {
+                        // The server did not respond fast enough,
+                        // time the connection out.
+                        alert(AlertLevel::Critical, AlertDescription::UserCanceled);
+                        m_context.connection_finished = true;
+                        m_context.tls_buffer.clear();
+                        m_context.error_code = Error::TimedOut;
+                        m_context.critical_error = (u8)Error::TimedOut;
+                        check_connection_state(false); // Notify the client.
+                    } else {
+                        // Extend the timer, we are too slow.
+                        m_handshake_timeout_timer->restart(m_max_wait_time_for_handshake_in_seconds * 1000);
+                    }
+                },
+                this);
+            write_into_socket();
+            m_handshake_timeout_timer->start();
+            m_context.handshake_initiation_timestamp = Core::DateTime::now().timestamp();
+        });
+        m_has_scheduled_write_flush = true;
+
+        if (on_tls_connected)
+            on_tls_connected();
+    };
+    bool success = Core::Socket::common_connect(saddr, length);
+    if (!success)
+        return false;
+
+    return true;
+}
+
+void TLSv12::read_from_socket()
+{
+    if (m_context.application_buffer.size() > 0) {
+        deferred_invoke([&](auto&) { read_from_socket(); });
+        if (on_tls_ready_to_read)
+            on_tls_ready_to_read(*this);
+    }
+
+    if (!check_connection_state(true))
+        return;
+
+    consume(Core::Socket::read(4096));
+}
+
+void TLSv12::write_into_socket()
+{
+#ifdef TLS_DEBUG
+    dbg() << "Flushing cached records: " << m_context.tls_buffer.size() << " established? " << is_established();
+#endif
+    m_has_scheduled_write_flush = false;
+    if (!check_connection_state(false))
+        return;
+    flush();
+
+    if (!is_established())
+        return;
+
+    if (!m_context.application_buffer.size()) // hey client, you still have stuff to read...
+        if (on_tls_ready_to_write)
+            on_tls_ready_to_write(*this);
+}
+
+bool TLSv12::check_connection_state(bool read)
+{
+    if (!Core::Socket::is_open() || !Core::Socket::is_connected() || Core::Socket::eof()) {
+        // an abrupt closure (the server is a jerk)
+#ifdef TLS_DEBUG
+        dbgln("Socket not open, assuming abrupt closure");
+#endif
+        m_context.connection_finished = true;
+    }
+    if (m_context.critical_error) {
+#ifdef TLS_DEBUG
+        dbg() << "CRITICAL ERROR " << m_context.critical_error << " :(";
+#endif
+        if (on_tls_error)
+            on_tls_error((AlertDescription)m_context.critical_error);
+        return false;
+    }
+    if (((read && m_context.application_buffer.size() == 0) || !read) && m_context.connection_finished) {
+        if (m_context.application_buffer.size() == 0) {
+            if (on_tls_finished)
+                on_tls_finished();
+        }
+        if (m_context.tls_buffer.size()) {
+#ifdef TLS_DEBUG
+            dbg() << "connection closed without finishing data transfer, " << m_context.tls_buffer.size() << " bytes still in buffer & " << m_context.application_buffer.size() << " bytes in application buffer";
+#endif
+        } else {
+            m_context.connection_finished = false;
+#ifdef TLS_DEBUG
+            dbgln("FINISHED");
+#endif
+        }
+        if (!m_context.application_buffer.size()) {
+            m_context.connection_status = ConnectionStatus::Disconnected;
+            return false;
+        }
+    }
+    return true;
+}
+
+bool TLSv12::flush()
+{
+    auto out_buffer = write_buffer().data();
+    size_t out_buffer_index { 0 };
+    size_t out_buffer_length = write_buffer().size();
+
+    if (out_buffer_length == 0)
+        return true;
+
+#ifdef TLS_DEBUG
+    dbgln("SENDING...");
+    print_buffer(out_buffer, out_buffer_length);
+#endif
+    if (Core::Socket::write(&out_buffer[out_buffer_index], out_buffer_length)) {
+        write_buffer().clear();
+        return true;
+    }
+    if (m_context.send_retries++ == 10) {
+        // drop the records, we can't send
+#ifdef TLS_DEBUG
+        dbg() << "Dropping " << write_buffer().size() << " bytes worth of TLS records as max retries has been reached";
+#endif
+        write_buffer().clear();
+        m_context.send_retries = 0;
+    }
+    return false;
+}
+
+}

Userland/Libraries/LibTLS/TLSPacketBuilder.h

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/Endian.h>
+#include <AK/Types.h>
+
+namespace TLS {
+
+enum class MessageType : u8 {
+    ChangeCipher = 0x14,
+    Alert = 0x15,
+    Handshake = 0x16,
+    ApplicationData = 0x17,
+};
+
+enum class Version : u16 {
+    V10 = 0x0301,
+    V11 = 0x0302,
+    V12 = 0x0303,
+    V13 = 0x0304
+};
+
+class PacketBuilder {
+public:
+    PacketBuilder(MessageType type, u16 version, size_t size_hint = 0xfdf)
+        : PacketBuilder(type, (Version)version, size_hint)
+    {
+    }
+
+    PacketBuilder(MessageType type, Version version, size_t size_hint = 0xfdf)
+    {
+        m_packet_data = ByteBuffer::create_uninitialized(size_hint + 16);
+        m_current_length = 5;
+        m_packet_data[0] = (u8)type;
+        *(u16*)m_packet_data.offset_pointer(1) = AK::convert_between_host_and_network_endian((u16)version);
+    }
+
+    inline void append(u16 value)
+    {
+        value = AK::convert_between_host_and_network_endian(value);
+        append((const u8*)&value, sizeof(value));
+    }
+    inline void append(u8 value)
+    {
+        append((const u8*)&value, sizeof(value));
+    }
+    inline void append(ReadonlyBytes data)
+    {
+        append(data.data(), data.size());
+    }
+    inline void append_u24(u32 value)
+    {
+        u8 buf[3];
+        buf[0] = value / 0x10000;
+        value %= 0x10000;
+        buf[1] = value / 0x100;
+        value %= 0x100;
+        buf[2] = value;
+
+        append(buf, 3);
+    }
+    inline void append(const u8* data, size_t bytes)
+    {
+        if (bytes == 0)
+            return;
+
+        auto old_length = m_current_length;
+        m_current_length += bytes;
+
+        if (m_packet_data.size() < m_current_length) {
+            m_packet_data.grow(m_current_length);
+        }
+
+        m_packet_data.overwrite(old_length, data, bytes);
+    }
+    inline ByteBuffer build()
+    {
+        auto length = m_current_length;
+        m_current_length = 0;
+        return m_packet_data.slice(0, length);
+    }
+    inline void set(size_t offset, u8 value)
+    {
+        ASSERT(offset < m_current_length);
+        m_packet_data[offset] = value;
+    }
+    size_t length() const { return m_current_length; }
+
+private:
+    ByteBuffer m_packet_data;
+    size_t m_current_length;
+};
+
+}

Userland/Libraries/LibTLS/TLSv12.cpp

@@ -0,0 +1,887 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Endian.h>
+#include <LibCore/ConfigFile.h>
+#include <LibCore/DateTime.h>
+#include <LibCore/Timer.h>
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/ASN1/PEM.h>
+#include <LibCrypto/PK/Code/EMSA_PSS.h>
+#include <LibTLS/TLSv12.h>
+
+#ifndef SOCK_NONBLOCK
+#    include <sys/ioctl.h>
+#endif
+
+//#define TLS_DEBUG
+
+namespace {
+struct OIDChain {
+    OIDChain* root { nullptr };
+    u8* oid { nullptr };
+};
+}
+
+namespace TLS {
+
+// "for now" q&d implementation of ASN1
+namespace {
+
+static bool _asn1_is_field_present(const u32* fields, const u32* prefix)
+{
+    size_t i = 0;
+    while (prefix[i]) {
+        if (fields[i] != prefix[i])
+            return false;
+        ++i;
+    }
+    return true;
+}
+
+static bool _asn1_is_oid(const u8* oid, const u8* compare, size_t length = 3)
+{
+    size_t i = 0;
+    while (oid[i] && i < length) {
+        if (oid[i] != compare[i])
+            return false;
+        ++i;
+    }
+    return true;
+}
+
+static bool _asn1_is_oid_in_chain(OIDChain* reference_chain, const u8* lookup, size_t lookup_length = 3)
+{
+    auto is_oid = [](const u8* oid, size_t oid_length, const u8* compare, size_t compare_length) {
+        if (oid_length < compare_length)
+            compare_length = oid_length;
+        for (size_t i = 0; i < compare_length; i++) {
+            if (oid[i] != compare[i])
+                return false;
+        }
+        return true;
+    };
+    for (; reference_chain; reference_chain = reference_chain->root) {
+        if (reference_chain->oid)
+            if (is_oid(reference_chain->oid, 16, lookup, lookup_length))
+                return true;
+    }
+    return false;
+}
+
+static bool _set_algorithm(CertificateKeyAlgorithm& algorithm, const u8* value, size_t length)
+{
+    if (length == 7) {
+        // Elliptic Curve pubkey
+        dbgln("Cert.algorithm: EC, unsupported");
+        return false;
+    }
+
+    if (length == 8) {
+        // named EC key
+        dbg() << "Cert.algorithm: Named EC (" << *value << "), unsupported";
+        return false;
+    }
+
+    if (length == 5) {
+        // named EC SECP key
+        dbg() << "Cert.algorithm: Named EC secp (" << *value << "), unsupported";
+        return false;
+    }
+
+    if (length != 9) {
+        dbgln("Invalid certificate algorithm");
+        return false;
+    }
+
+    if (_asn1_is_oid(value, Constants::RSA_SIGN_RSA_OID, 9)) {
+        algorithm = CertificateKeyAlgorithm::RSA_RSA;
+        return true;
+    }
+
+    if (_asn1_is_oid(value, Constants::RSA_SIGN_SHA256_OID, 9)) {
+        algorithm = CertificateKeyAlgorithm::RSA_SHA256;
+        return true;
+    }
+
+    if (_asn1_is_oid(value, Constants::RSA_SIGN_SHA512_OID, 9)) {
+        algorithm = CertificateKeyAlgorithm::RSA_SHA512;
+        return true;
+    }
+
+    if (_asn1_is_oid(value, Constants::RSA_SIGN_SHA1_OID, 9)) {
+        algorithm = CertificateKeyAlgorithm::RSA_SHA1;
+        return true;
+    }
+
+    if (_asn1_is_oid(value, Constants::RSA_SIGN_MD5_OID, 9)) {
+        algorithm = CertificateKeyAlgorithm::RSA_MD5;
+        return true;
+    }
+
+    dbg() << "Unsupported RSA Signature mode " << value[8];
+    return false;
+}
+
+static size_t _get_asn1_length(const u8* buffer, size_t length, size_t& octets)
+{
+    octets = 0;
+    if (length < 1)
+        return 0;
+
+    u8 size = buffer[0];
+    if (size & 0x80) {
+        octets = size & 0x7f;
+        if (octets > length - 1) {
+            return 0;
+        }
+        auto reference_octets = octets;
+        if (octets > 4)
+            reference_octets = 4;
+        size_t long_size = 0, coeff = 1;
+        for (auto i = reference_octets; i > 0; --i) {
+            long_size += buffer[i] * coeff;
+            coeff *= 0x100;
+        }
+        ++octets;
+        return long_size;
+    }
+    ++octets;
+    return size;
+}
+
+static ssize_t _parse_asn1(const Context& context, Certificate& cert, const u8* buffer, size_t size, int level, u32* fields, u8* has_key, int client_cert, u8* root_oid, OIDChain* chain)
+{
+    OIDChain local_chain;
+    local_chain.root = chain;
+    size_t position = 0;
+
+    // parse DER...again
+    size_t index = 0;
+    u8 oid[16] { 0 };
+
+    local_chain.oid = oid;
+    if (has_key)
+        *has_key = 0;
+
+    u8 local_has_key = 0;
+    const u8* cert_data = nullptr;
+    size_t cert_length = 0;
+    while (position < size) {
+        size_t start_position = position;
+        if (size - position < 2) {
+            dbgln("not enough data for certificate size");
+            return (i8)Error::NeedMoreData;
+        }
+        u8 first = buffer[position++];
+        u8 type = first & 0x1f;
+        u8 constructed = first & 0x20;
+        size_t octets = 0;
+        u32 temp;
+        index++;
+
+        if (level <= 0xff)
+            fields[level - 1] = index;
+
+        size_t length = _get_asn1_length((const u8*)&buffer[position], size - position, octets);
+
+        if (octets > 4 || octets > size - position) {
+#ifdef TLS_DEBUG
+            dbgln("could not read the certificate");
+#endif
+            return position;
+        }
+
+        position += octets;
+        if (size - position < length) {
+#ifdef TLS_DEBUG
+            dbgln("not enough data for sequence");
+#endif
+            return (i8)Error::NeedMoreData;
+        }
+
+        if (length && constructed) {
+            switch (type) {
+            case 0x03:
+                break;
+            case 0x10:
+                if (level == 2 && index == 1) {
+                    cert_length = length + position - start_position;
+                    cert_data = buffer + start_position;
+                }
+                // public key data
+                if (!cert.version && _asn1_is_field_present(fields, Constants::priv_der_id)) {
+                    temp = length + position - start_position;
+                    if (cert.der.size() < temp) {
+                        cert.der.grow(temp);
+                    } else {
+                        cert.der.trim(temp);
+                    }
+                    cert.der.overwrite(0, buffer + start_position, temp);
+                }
+                break;
+
+            default:
+                break;
+            }
+            local_has_key = false;
+            _parse_asn1(context, cert, buffer + position, length, level + 1, fields, &local_has_key, client_cert, root_oid, &local_chain);
+            if ((local_has_key && (!context.is_server || client_cert)) || (client_cert || _asn1_is_field_present(fields, Constants::pk_id))) {
+                temp = length + position - start_position;
+                if (cert.der.size() < temp) {
+                    cert.der.grow(temp);
+                } else {
+                    cert.der.trim(temp);
+                }
+                cert.der.overwrite(0, buffer + start_position, temp);
+            }
+        } else {
+            switch (type) {
+            case 0x00:
+                return position;
+                break;
+            case 0x01:
+                temp = buffer[position];
+                break;
+            case 0x02:
+                if (_asn1_is_field_present(fields, Constants::pk_id)) {
+                    if (has_key)
+                        *has_key = true;
+
+                    if (index == 1)
+                        cert.public_key.set(
+                            Crypto::UnsignedBigInteger::import_data(buffer + position, length),
+                            cert.public_key.public_exponent());
+                    else if (index == 2)
+                        cert.public_key.set(
+                            cert.public_key.modulus(),
+                            Crypto::UnsignedBigInteger::import_data(buffer + position, length));
+                } else if (_asn1_is_field_present(fields, Constants::serial_id)) {
+                    cert.serial_number = Crypto::UnsignedBigInteger::import_data(buffer + position, length);
+                }
+                if (_asn1_is_field_present(fields, Constants::version_id)) {
+                    if (length == 1)
+                        cert.version = buffer[position];
+                }
+                if (chain && length > 2) {
+                    if (_asn1_is_oid_in_chain(chain, Constants::san_oid)) {
+                        StringView alt_name { &buffer[position], length };
+                        cert.SAN.append(alt_name);
+                    }
+                }
+                // print_buffer(ReadonlyBytes { buffer + position, length });
+                break;
+            case 0x03:
+                if (_asn1_is_field_present(fields, Constants::pk_id)) {
+                    if (has_key)
+                        *has_key = true;
+                }
+                if (_asn1_is_field_present(fields, Constants::sign_id)) {
+                    auto* value = buffer + position;
+                    auto len = length;
+                    if (!value[0] && len % 2) {
+                        ++value;
+                        --len;
+                    }
+                    cert.sign_key = ByteBuffer::copy(value, len);
+                } else {
+                    if (buffer[position] == 0 && length > 256) {
+                        _parse_asn1(context, cert, buffer + position + 1, length - 1, level + 1, fields, &local_has_key, client_cert, root_oid, &local_chain);
+                    } else {
+                        _parse_asn1(context, cert, buffer + position, length, level + 1, fields, &local_has_key, client_cert, root_oid, &local_chain);
+                    }
+                }
+                break;
+            case 0x04:
+                _parse_asn1(context, cert, buffer + position, length, level + 1, fields, &local_has_key, client_cert, root_oid, &local_chain);
+                break;
+            case 0x05:
+                break;
+            case 0x06:
+                if (_asn1_is_field_present(fields, Constants::pk_id)) {
+                    _set_algorithm(cert.key_algorithm, buffer + position, length);
+                }
+                if (_asn1_is_field_present(fields, Constants::algorithm_id)) {
+                    _set_algorithm(cert.algorithm, buffer + position, length);
+                }
+
+                if (length < 16)
+                    memcpy(oid, buffer + position, length);
+                else
+                    memcpy(oid, buffer + position, 16);
+                if (root_oid)
+                    memcpy(root_oid, oid, 16);
+                break;
+            case 0x09:
+                break;
+            case 0x17:
+            case 0x018:
+                // time
+                // ignore
+                break;
+            case 0x013:
+            case 0x0c:
+            case 0x14:
+            case 0x15:
+            case 0x16:
+            case 0x19:
+            case 0x1a:
+            case 0x1b:
+            case 0x1c:
+            case 0x1d:
+            case 0x1e:
+                // printable string and such
+                if (_asn1_is_field_present(fields, Constants::issurer_id)) {
+                    if (_asn1_is_oid(oid, Constants::country_oid)) {
+                        cert.issuer_country = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::state_oid)) {
+                        cert.issuer_state = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::location_oid)) {
+                        cert.issuer_location = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::entity_oid)) {
+                        cert.issuer_entity = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::subject_oid)) {
+                        cert.issuer_subject = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::unit_oid)) {
+                        cert.issuer_unit = String { (const char*)buffer + position, length };
+                    }
+                } else if (_asn1_is_field_present(fields, Constants::owner_id)) {
+                    if (_asn1_is_oid(oid, Constants::country_oid)) {
+                        cert.country = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::state_oid)) {
+                        cert.state = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::location_oid)) {
+                        cert.location = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::entity_oid)) {
+                        cert.entity = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::subject_oid)) {
+                        cert.subject = String { (const char*)buffer + position, length };
+                    } else if (_asn1_is_oid(oid, Constants::unit_oid)) {
+                        cert.unit = String { (const char*)buffer + position, length };
+                    }
+                }
+                break;
+            default:
+                // dbg() << "unused field " << type;
+                break;
+            }
+        }
+        position += length;
+    }
+    if (level == 2 && cert.sign_key.size() && cert_length && cert_data) {
+        cert.fingerprint.clear();
+        Crypto::Hash::Manager hash;
+        switch (cert.key_algorithm) {
+        case CertificateKeyAlgorithm::RSA_MD5:
+            hash.initialize(Crypto::Hash::HashKind::MD5);
+            break;
+        case CertificateKeyAlgorithm::RSA_SHA1:
+            hash.initialize(Crypto::Hash::HashKind::SHA1);
+            break;
+        case CertificateKeyAlgorithm::RSA_SHA256:
+            hash.initialize(Crypto::Hash::HashKind::SHA256);
+            break;
+        case CertificateKeyAlgorithm::RSA_SHA512:
+            hash.initialize(Crypto::Hash::HashKind::SHA512);
+            break;
+        default:
+#ifdef TLS_DEBUG
+            dbg() << "Unsupported hash mode " << (u32)cert.key_algorithm;
+#endif
+            // fallback to md5, it will fail later
+            hash.initialize(Crypto::Hash::HashKind::MD5);
+            break;
+        }
+        hash.update(cert_data, cert_length);
+        auto fingerprint = hash.digest();
+        cert.fingerprint.grow(fingerprint.data_length());
+        cert.fingerprint.overwrite(0, fingerprint.immutable_data(), fingerprint.data_length());
+#ifdef TLS_DEBUG
+        dbgln("Certificate fingerprint:");
+        print_buffer(cert.fingerprint);
+#endif
+    }
+    return position;
+}
+}
+
+Optional<Certificate> TLSv12::parse_asn1(ReadonlyBytes buffer, bool) const
+{
+    // FIXME: Our ASN.1 parser is not quite up to the task of
+    //        parsing this X.509 certificate, so for the
+    //        time being, we will "parse" the certificate
+    //        manually right here.
+
+    Certificate cert;
+    u32 fields[0xff];
+
+    _parse_asn1(m_context, cert, buffer.data(), buffer.size(), 1, fields, nullptr, 0, nullptr, nullptr);
+
+#ifdef TLS_DEBUG
+    dbg() << "Certificate issued for " << cert.subject << " by " << cert.issuer_subject;
+#endif
+
+    return cert;
+}
+
+ssize_t TLSv12::handle_certificate(ReadonlyBytes buffer)
+{
+    ssize_t res = 0;
+
+    if (buffer.size() < 3) {
+#ifdef 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];
+
+#ifdef TLS_DEBUG
+    dbg() << "total length: " << certificate_total_length;
+#endif
+
+    if (certificate_total_length <= 4)
+        return 3 * certificate_total_length;
+
+    res += 3;
+
+    if (certificate_total_length > buffer.size() - res) {
+#ifdef 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) {
+#ifdef 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) {
+#ifdef 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) {
+                dbg() << "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) {
+                dbg() << "invalid certificate size (expected " << remaining << " but got " << 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) {
+            dbg() << "extraneous " << remaining << " bytes left over after parsing certificates";
+        }
+        size -= certificate_size + 3;
+        res += certificate_size;
+    }
+    if (!valid_certificate)
+        return (i8)Error::UnsupportedCertificate;
+
+    if ((size_t)res != buffer.size())
+        dbg() << "some data left unread: " << (size_t)res << " bytes out of " << buffer.size();
+
+    return res;
+}
+
+void TLSv12::consume(ReadonlyBytes record)
+{
+    if (m_context.critical_error) {
+        dbg() << "There has been a critical error (" << (i8)m_context.critical_error << "), refusing to continue";
+        return;
+    }
+
+    if (record.size() == 0) {
+        return;
+    }
+
+#ifdef TLS_DEBUG
+    dbg() << "Consuming " << record.size() << " bytes";
+#endif
+
+    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 };
+#ifdef TLS_DEBUG
+    dbg() << "message buffer length " << buffer_length;
+#endif
+    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) {
+#ifdef TLS_DEBUG
+            dbg() << "Need more data: " << length << " | " << buffer_length;
+#endif
+            break;
+        }
+        auto consumed = handle_message(m_context.message_buffer.bytes().slice(index, length));
+
+#ifdef TLS_DEBUG
+        if (consumed > 0)
+            dbg() << "consumed " << (size_t)consumed << " bytes";
+        else
+            dbg() << "error: " << (int)consumed;
+#endif
+
+        if (consumed != (i8)Error::NeedMoreData) {
+            if (consumed < 0) {
+                dbg() << "Consumed an error: " << (int)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) {
+        dbg() << "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:
+        dbg() << "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 (!not_before.is_empty()) {
+        if (now.is_before(not_before)) {
+            dbg() << "certificate expired (not yet valid, signed for " << not_before << ")";
+            return false;
+        }
+    }
+
+    if (!not_after.is_empty()) {
+        if (!now.is_before(not_after)) {
+            dbg() << "certificate expired (expiry date " << not_after << ")";
+            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) {
+            dbg() << "- No cipher suite in common with " << m_context.SNI;
+        } else {
+            dbgln("- Unknown internal issue");
+        }
+        break;
+    case AlertDescription::InsufficientSecurity:
+        dbg() << "- No cipher suite in common with " << m_context.SNI << " (the server is oh so secure)";
+        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())
+            dbg() << "Certificate for " << cert.subject << " by " << cert.issuer_subject << " is invalid, things may or may not work!";
+        // FIXME: Figure out what we should do when our root certs are invalid.
+    }
+    m_context.root_ceritificates = move(certificates);
+}
+
+bool Context::verify_chain() const
+{
+    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);
+        chain.set(cert.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, 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))
+                dbg() << "Self-signed warning: Certificate for " << it.key << " is self-signed";
+            continue;
+        }
+
+        auto ref = chain.get(it.value);
+        if (!ref.has_value()) {
+            dbg() << "Certificate for " << it.key << " is not signed by anyone we trust (" << it.value << ")";
+            return false;
+        }
+
+        if (ref.value() == it.key) // Allow (but warn about) mutually recursively signed cert A <-> B.
+            dbg() << "Co-dependency warning: Certificate for " << ref.value() << " is issued by " << it.key << ", which itself is issued by " << 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))
+            return i;
+        for (auto& san : cert.SAN) {
+            if (wildcard_matches(host, san))
+                return i;
+        }
+    }
+
+    return {};
+}
+
+TLSv12::TLSv12(Core::Object* parent, Version version)
+    : Core::Socket(Core::Socket::Type::TCP, parent)
+{
+    m_context.version = version;
+    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, 0);
+    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");
+    for (auto& entity : config->groups()) {
+        Certificate cert;
+        cert.subject = entity;
+        cert.issuer_subject = config->read_entry(entity, "issuer_subject", entity);
+        cert.country = config->read_entry(entity, "country");
+        m_ca_certificates.append(move(cert));
+    }
+}
+
+}

Userland/Libraries/LibTLS/TLSv12.h

@@ -0,0 +1,509 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Certificate.h"
+#include <AK/IPv4Address.h>
+#include <AK/WeakPtr.h>
+#include <LibCore/Notifier.h>
+#include <LibCore/Socket.h>
+#include <LibCore/TCPSocket.h>
+#include <LibCrypto/Authentication/HMAC.h>
+#include <LibCrypto/BigInt/UnsignedBigInteger.h>
+#include <LibCrypto/Cipher/AES.h>
+#include <LibCrypto/Hash/HashManager.h>
+#include <LibCrypto/PK/RSA.h>
+#include <LibTLS/TLSPacketBuilder.h>
+
+namespace TLS {
+
+inline void print_buffer(ReadonlyBytes buffer)
+{
+    for (size_t i { 0 }; i < buffer.size(); ++i)
+        dbgprintf("%02x ", buffer[i]);
+    dbgprintf("\n");
+}
+
+inline void print_buffer(const ByteBuffer& buffer)
+{
+    print_buffer(buffer.bytes());
+}
+
+inline void print_buffer(const u8* buffer, size_t size)
+{
+    print_buffer(ReadonlyBytes { buffer, size });
+}
+
+class Socket;
+
+enum class CipherSuite {
+    Invalid = 0,
+    AES_128_GCM_SHA256 = 0x1301,
+    AES_256_GCM_SHA384 = 0x1302,
+    AES_128_CCM_SHA256 = 0x1304,
+    AES_128_CCM_8_SHA256 = 0x1305,
+
+    // We support these
+    RSA_WITH_AES_128_CBC_SHA = 0x002F,
+    RSA_WITH_AES_256_CBC_SHA = 0x0035,
+    RSA_WITH_AES_128_CBC_SHA256 = 0x003C,
+    RSA_WITH_AES_256_CBC_SHA256 = 0x003D,
+    // TODO
+    RSA_WITH_AES_128_GCM_SHA256 = 0x009C,
+    RSA_WITH_AES_256_GCM_SHA384 = 0x009D,
+};
+
+#define ENUMERATE_ALERT_DESCRIPTIONS                        \
+    ENUMERATE_ALERT_DESCRIPTION(CloseNotify, 0)             \
+    ENUMERATE_ALERT_DESCRIPTION(UnexpectedMessage, 10)      \
+    ENUMERATE_ALERT_DESCRIPTION(BadRecordMAC, 20)           \
+    ENUMERATE_ALERT_DESCRIPTION(DecryptionFailed, 21)       \
+    ENUMERATE_ALERT_DESCRIPTION(RecordOverflow, 22)         \
+    ENUMERATE_ALERT_DESCRIPTION(DecompressionFailure, 30)   \
+    ENUMERATE_ALERT_DESCRIPTION(HandshakeFailure, 40)       \
+    ENUMERATE_ALERT_DESCRIPTION(NoCertificate, 41)          \
+    ENUMERATE_ALERT_DESCRIPTION(BadCertificate, 42)         \
+    ENUMERATE_ALERT_DESCRIPTION(UnsupportedCertificate, 43) \
+    ENUMERATE_ALERT_DESCRIPTION(CertificateRevoked, 44)     \
+    ENUMERATE_ALERT_DESCRIPTION(CertificateExpired, 45)     \
+    ENUMERATE_ALERT_DESCRIPTION(CertificateUnknown, 46)     \
+    ENUMERATE_ALERT_DESCRIPTION(IllegalParameter, 47)       \
+    ENUMERATE_ALERT_DESCRIPTION(UnknownCA, 48)              \
+    ENUMERATE_ALERT_DESCRIPTION(AccessDenied, 49)           \
+    ENUMERATE_ALERT_DESCRIPTION(DecodeError, 50)            \
+    ENUMERATE_ALERT_DESCRIPTION(DecryptError, 51)           \
+    ENUMERATE_ALERT_DESCRIPTION(ExportRestriction, 60)      \
+    ENUMERATE_ALERT_DESCRIPTION(ProtocolVersion, 70)        \
+    ENUMERATE_ALERT_DESCRIPTION(InsufficientSecurity, 71)   \
+    ENUMERATE_ALERT_DESCRIPTION(InternalError, 80)          \
+    ENUMERATE_ALERT_DESCRIPTION(InappropriateFallback, 86)  \
+    ENUMERATE_ALERT_DESCRIPTION(UserCanceled, 90)           \
+    ENUMERATE_ALERT_DESCRIPTION(NoRenegotiation, 100)       \
+    ENUMERATE_ALERT_DESCRIPTION(UnsupportedExtension, 110)  \
+    ENUMERATE_ALERT_DESCRIPTION(NoError, 255)
+
+enum class AlertDescription : u8 {
+#define ENUMERATE_ALERT_DESCRIPTION(name, value) name = value,
+    ENUMERATE_ALERT_DESCRIPTIONS
+#undef ENUMERATE_ALERT_DESCRIPTION
+};
+
+constexpr static const char* alert_name(AlertDescription descriptor)
+{
+#define ENUMERATE_ALERT_DESCRIPTION(name, value) \
+    case AlertDescription::name:                 \
+        return #name;
+
+    switch (descriptor) {
+        ENUMERATE_ALERT_DESCRIPTIONS
+    }
+
+    return "Unknown";
+#undef ENUMERATE_ALERT_DESCRIPTION
+}
+
+enum class Error : i8 {
+    NoError = 0,
+    UnknownError = -1,
+    BrokenPacket = -2,
+    NotUnderstood = -3,
+    NoCommonCipher = -5,
+    UnexpectedMessage = -6,
+    CloseConnection = -7,
+    CompressionNotSupported = -8,
+    NotVerified = -9,
+    NotSafe = -10,
+    IntegrityCheckFailed = -11,
+    ErrorAlert = -12,
+    BrokenConnection = -13,
+    BadCertificate = -14,
+    UnsupportedCertificate = -15,
+    NoRenegotiation = -16,
+    FeatureNotSupported = -17,
+    DecryptionFailed = -20,
+    NeedMoreData = -21,
+    TimedOut = -22,
+};
+
+enum class AlertLevel : u8 {
+    Warning = 0x01,
+    Critical = 0x02
+};
+
+enum HandshakeType {
+    HelloRequest = 0x00,
+    ClientHello = 0x01,
+    ServerHello = 0x02,
+    HelloVerifyRequest = 0x03,
+    CertificateMessage = 0x0b,
+    ServerKeyExchange = 0x0c,
+    CertificateRequest = 0x0d,
+    ServerHelloDone = 0x0e,
+    CertificateVerify = 0x0f,
+    ClientKeyExchange = 0x10,
+    Finished = 0x14
+};
+
+enum class HandshakeExtension : u16 {
+    ServerName = 0x00,
+    ApplicationLayerProtocolNegotiation = 0x10,
+    SignatureAlgorithms = 0x0d,
+};
+
+enum class WritePacketStage {
+    Initial = 0,
+    ClientHandshake = 1,
+    ServerHandshake = 2,
+    Finished = 3,
+};
+
+enum class ConnectionStatus {
+    Disconnected,
+    Negotiating,
+    KeyExchange,
+    Renegotiating,
+    Established,
+};
+
+enum ClientVerificationStaus {
+    Verified,
+    VerificationNeeded,
+};
+
+struct Context {
+    String to_string() const;
+    bool verify() const;
+    bool verify_chain() const;
+
+    static void print_file(const StringView& fname);
+
+    u8 remote_random[32];
+    // To be predictable
+    u8 local_random[32];
+    u8 session_id[32];
+    u8 session_id_size { 0 };
+    CipherSuite cipher;
+    Version version;
+    bool is_server { false };
+    Vector<Certificate> certificates;
+    Certificate private_key;
+    Vector<Certificate> client_certificates;
+    ByteBuffer master_key;
+    ByteBuffer premaster_key;
+    u8 cipher_spec_set { 0 };
+    struct {
+        int created { 0 };
+        u8 remote_mac[32];
+        u8 local_mac[32];
+        u8 local_iv[16];
+        u8 remote_iv[16];
+        u8 local_aead_iv[4];
+        u8 remote_aead_iv[4];
+    } crypto;
+
+    Crypto::Hash::Manager handshake_hash;
+
+    ByteBuffer message_buffer;
+    u64 remote_sequence_number { 0 };
+    u64 local_sequence_number { 0 };
+
+    ConnectionStatus connection_status { ConnectionStatus::Disconnected };
+    u8 critical_error { 0 };
+    Error error_code { Error::NoError };
+
+    ByteBuffer tls_buffer;
+
+    ByteBuffer application_buffer;
+
+    bool is_child { false };
+
+    String SNI; // I hate your existence
+
+    u8 request_client_certificate { 0 };
+
+    ByteBuffer cached_handshake;
+
+    ClientVerificationStaus client_verified { Verified };
+
+    bool connection_finished { false };
+
+    // message flags
+    u8 handshake_messages[11] { 0 };
+    ByteBuffer user_data;
+    Vector<Certificate> root_ceritificates;
+
+    Vector<String> alpn;
+    StringView negotiated_alpn;
+
+    size_t send_retries { 0 };
+
+    time_t handshake_initiation_timestamp { 0 };
+};
+
+class TLSv12 : public Core::Socket {
+    C_OBJECT(TLSv12)
+public:
+    ByteBuffer& write_buffer() { return m_context.tls_buffer; }
+    bool is_established() const { return m_context.connection_status == ConnectionStatus::Established; }
+    virtual bool connect(const String&, int) override;
+
+    void set_sni(const StringView& sni)
+    {
+        if (m_context.is_server || m_context.critical_error || m_context.connection_status != ConnectionStatus::Disconnected) {
+            dbgln("invalid state for set_sni");
+            return;
+        }
+        m_context.SNI = sni;
+    }
+
+    Optional<Certificate> parse_asn1(ReadonlyBytes, bool client_cert = false) const;
+    bool load_certificates(ReadonlyBytes pem_buffer);
+    bool load_private_key(ReadonlyBytes pem_buffer);
+
+    void set_root_certificates(Vector<Certificate>);
+
+    bool add_client_key(ReadonlyBytes certificate_pem_buffer, ReadonlyBytes key_pem_buffer);
+    bool add_client_key(Certificate certificate)
+    {
+        m_context.client_certificates.append(move(certificate));
+        return true;
+    }
+
+    ByteBuffer finish_build();
+
+    const StringView& alpn() const { return m_context.negotiated_alpn; }
+    void add_alpn(const StringView& alpn);
+    bool has_alpn(const StringView& alpn) const;
+
+    bool supports_cipher(CipherSuite suite) const
+    {
+        return suite == CipherSuite::RSA_WITH_AES_128_CBC_SHA256
+            || suite == CipherSuite::RSA_WITH_AES_256_CBC_SHA256
+            || suite == CipherSuite::RSA_WITH_AES_128_CBC_SHA
+            || suite == CipherSuite::RSA_WITH_AES_256_CBC_SHA
+            || suite == CipherSuite::RSA_WITH_AES_128_GCM_SHA256;
+    }
+
+    bool supports_version(Version v) const
+    {
+        return v == Version::V12;
+    }
+
+    Optional<ByteBuffer> read();
+    ByteBuffer read(size_t max_size);
+
+    bool write(ReadonlyBytes);
+    void alert(AlertLevel, AlertDescription);
+
+    bool can_read_line() const { return m_context.application_buffer.size() && memchr(m_context.application_buffer.data(), '\n', m_context.application_buffer.size()); }
+    bool can_read() const { return m_context.application_buffer.size() > 0; }
+    String read_line(size_t max_size);
+
+    Function<void(TLSv12&)> on_tls_ready_to_read;
+    Function<void(TLSv12&)> on_tls_ready_to_write;
+    Function<void(AlertDescription)> on_tls_error;
+    Function<void()> on_tls_connected;
+    Function<void()> on_tls_finished;
+    Function<void(TLSv12&)> on_tls_certificate_request;
+
+private:
+    explicit TLSv12(Core::Object* parent, Version version = Version::V12);
+
+    virtual bool common_connect(const struct sockaddr*, socklen_t) override;
+
+    void consume(ReadonlyBytes record);
+
+    ByteBuffer hmac_message(const ReadonlyBytes& buf, const Optional<ReadonlyBytes> buf2, size_t mac_length, bool local = false);
+    void ensure_hmac(size_t digest_size, bool local);
+
+    void update_packet(ByteBuffer& packet);
+    void update_hash(ReadonlyBytes in);
+
+    void write_packet(ByteBuffer& packet);
+
+    ByteBuffer build_client_key_exchange();
+    ByteBuffer build_server_key_exchange();
+
+    ByteBuffer build_hello();
+    ByteBuffer build_finished();
+    ByteBuffer build_certificate();
+    ByteBuffer build_done();
+    ByteBuffer build_alert(bool critical, u8 code);
+    ByteBuffer build_change_cipher_spec();
+    ByteBuffer build_verify_request();
+    void build_random(PacketBuilder&);
+
+    bool flush();
+    void write_into_socket();
+    void read_from_socket();
+
+    bool check_connection_state(bool read);
+
+    ssize_t handle_hello(ReadonlyBytes, WritePacketStage&);
+    ssize_t handle_finished(ReadonlyBytes, WritePacketStage&);
+    ssize_t handle_certificate(ReadonlyBytes);
+    ssize_t handle_server_key_exchange(ReadonlyBytes);
+    ssize_t handle_server_hello_done(ReadonlyBytes);
+    ssize_t handle_verify(ReadonlyBytes);
+    ssize_t handle_payload(ReadonlyBytes);
+    ssize_t handle_message(ReadonlyBytes);
+    ssize_t handle_random(ReadonlyBytes);
+
+    size_t asn1_length(ReadonlyBytes, size_t* octets);
+
+    void pseudorandom_function(Bytes output, ReadonlyBytes secret, const u8* label, size_t label_length, ReadonlyBytes seed, ReadonlyBytes seed_b);
+
+    size_t key_length() const
+    {
+        switch (m_context.cipher) {
+        case CipherSuite::AES_128_CCM_8_SHA256:
+        case CipherSuite::AES_128_CCM_SHA256:
+        case CipherSuite::AES_128_GCM_SHA256:
+        case CipherSuite::Invalid:
+        case CipherSuite::RSA_WITH_AES_128_CBC_SHA256:
+        case CipherSuite::RSA_WITH_AES_128_CBC_SHA:
+        case CipherSuite::RSA_WITH_AES_128_GCM_SHA256:
+        default:
+            return 128 / 8;
+        case CipherSuite::AES_256_GCM_SHA384:
+        case CipherSuite::RSA_WITH_AES_256_CBC_SHA:
+        case CipherSuite::RSA_WITH_AES_256_CBC_SHA256:
+        case CipherSuite::RSA_WITH_AES_256_GCM_SHA384:
+            return 256 / 8;
+        }
+    }
+    size_t mac_length() const
+    {
+        switch (m_context.cipher) {
+        case CipherSuite::RSA_WITH_AES_128_CBC_SHA:
+        case CipherSuite::RSA_WITH_AES_256_CBC_SHA:
+            return Crypto::Hash::SHA1::digest_size();
+        case CipherSuite::AES_256_GCM_SHA384:
+        case CipherSuite::RSA_WITH_AES_256_GCM_SHA384:
+            return Crypto::Hash::SHA512::digest_size();
+        case CipherSuite::AES_128_CCM_8_SHA256:
+        case CipherSuite::AES_128_CCM_SHA256:
+        case CipherSuite::AES_128_GCM_SHA256:
+        case CipherSuite::Invalid:
+        case CipherSuite::RSA_WITH_AES_128_CBC_SHA256:
+        case CipherSuite::RSA_WITH_AES_128_GCM_SHA256:
+        case CipherSuite::RSA_WITH_AES_256_CBC_SHA256:
+        default:
+            return Crypto::Hash::SHA256::digest_size();
+        }
+    }
+    size_t iv_length() const
+    {
+        switch (m_context.cipher) {
+        case CipherSuite::AES_128_CCM_8_SHA256:
+        case CipherSuite::AES_128_CCM_SHA256:
+        case CipherSuite::Invalid:
+        case CipherSuite::RSA_WITH_AES_128_CBC_SHA256:
+        case CipherSuite::RSA_WITH_AES_128_CBC_SHA:
+        case CipherSuite::RSA_WITH_AES_256_CBC_SHA256:
+        case CipherSuite::RSA_WITH_AES_256_CBC_SHA:
+        default:
+            return 16;
+        case CipherSuite::AES_128_GCM_SHA256:
+        case CipherSuite::AES_256_GCM_SHA384:
+        case CipherSuite::RSA_WITH_AES_128_GCM_SHA256:
+        case CipherSuite::RSA_WITH_AES_256_GCM_SHA384:
+            return 8; // 4 bytes of fixed IV, 8 random (nonce) bytes, 4 bytes for counter
+                      // GCM specifically asks us to transmit only the nonce, the counter is zero
+                      // and the fixed IV is derived from the premaster key.
+        }
+    }
+
+    bool is_aead() const
+    {
+        switch (m_context.cipher) {
+        case CipherSuite::AES_128_GCM_SHA256:
+        case CipherSuite::AES_256_GCM_SHA384:
+        case CipherSuite::RSA_WITH_AES_128_GCM_SHA256:
+        case CipherSuite::RSA_WITH_AES_256_GCM_SHA384:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    bool expand_key();
+
+    bool compute_master_secret(size_t length);
+
+    Optional<size_t> verify_chain_and_get_matching_certificate(const StringView& host) const;
+
+    void try_disambiguate_error() const;
+
+    Context m_context;
+
+    OwnPtr<Crypto::Authentication::HMAC<Crypto::Hash::Manager>> m_hmac_local;
+    OwnPtr<Crypto::Authentication::HMAC<Crypto::Hash::Manager>> m_hmac_remote;
+
+    struct {
+        OwnPtr<Crypto::Cipher::AESCipher::CBCMode> cbc;
+        OwnPtr<Crypto::Cipher::AESCipher::GCMMode> gcm;
+    } m_aes_local, m_aes_remote;
+
+    bool m_has_scheduled_write_flush { false };
+    i32 m_max_wait_time_for_handshake_in_seconds { 10 };
+
+    RefPtr<Core::Timer> m_handshake_timeout_timer;
+};
+
+namespace Constants {
+constexpr static const u32 version_id[] { 1, 1, 1, 0 };
+constexpr static const u32 pk_id[] { 1, 1, 7, 0 };
+constexpr static const u32 serial_id[] { 1, 1, 2, 1, 0 };
+constexpr static const u32 issurer_id[] { 1, 1, 4, 0 };
+constexpr static const u32 owner_id[] { 1, 1, 6, 0 };
+constexpr static const u32 validity_id[] { 1, 1, 5, 0 };
+constexpr static const u32 algorithm_id[] { 1, 1, 3, 0 };
+constexpr static const u32 sign_id[] { 1, 3, 2, 1, 0 };
+constexpr static const u32 priv_id[] { 1, 4, 0 };
+constexpr static const u32 priv_der_id[] { 1, 3, 1, 0 };
+constexpr static const u32 ecc_priv_id[] { 1, 2, 0 };
+
+constexpr static const u8 country_oid[] { 0x55, 0x04, 0x06, 0x00 };
+constexpr static const u8 state_oid[] { 0x55, 0x04, 0x08, 0x00 };
+constexpr static const u8 location_oid[] { 0x55, 0x04, 0x07, 0x00 };
+constexpr static const u8 entity_oid[] { 0x55, 0x04, 0x0A, 0x00 };
+constexpr static const u8 subject_oid[] { 0x55, 0x04, 0x03, 0x00 };
+constexpr static const u8 unit_oid[] { 0x55, 0x04, 0x0B, 0x00 };
+constexpr static const u8 san_oid[] { 0x55, 0x1D, 0x11, 0x00 };
+constexpr static const u8 ocsp_oid[] { 0x2B, 0x06, 0x01, 0x05, 0x05, 0x07, 0x30, 0x01, 0x00 };
+
+static constexpr const u8 RSA_SIGN_RSA_OID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x00 };
+static constexpr const u8 RSA_SIGN_MD5_OID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x04, 0x00 };
+static constexpr const u8 RSA_SIGN_SHA1_OID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x05, 0x00 };
+static constexpr const u8 RSA_SIGN_SHA256_OID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x00 };
+static constexpr const u8 RSA_SIGN_SHA384_OID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0c, 0x00 };
+static constexpr const u8 RSA_SIGN_SHA512_OID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0d, 0x00 };
+
+}
+
+}