zig/lib/std/crypto/tls/Client.zig
Jacob Young eaa6218f09 x86_64: fix errors compiling the compiler
This fixes issues targetting both `x86_64-linux` and `x86_64-macos` with
the self-hosted backend.
2024-02-04 22:58:38 -05:00

1469 lines
71 KiB
Zig

const std = @import("../../std.zig");
const tls = std.crypto.tls;
const Client = @This();
const net = std.net;
const mem = std.mem;
const crypto = std.crypto;
const assert = std.debug.assert;
const Certificate = std.crypto.Certificate;
const max_ciphertext_len = tls.max_ciphertext_len;
const hkdfExpandLabel = tls.hkdfExpandLabel;
const int2 = tls.int2;
const int3 = tls.int3;
const array = tls.array;
const enum_array = tls.enum_array;
read_seq: u64,
write_seq: u64,
/// The starting index of cleartext bytes inside `partially_read_buffer`.
partial_cleartext_idx: u15,
/// The ending index of cleartext bytes inside `partially_read_buffer` as well
/// as the starting index of ciphertext bytes.
partial_ciphertext_idx: u15,
/// The ending index of ciphertext bytes inside `partially_read_buffer`.
partial_ciphertext_end: u15,
/// When this is true, the stream may still not be at the end because there
/// may be data in `partially_read_buffer`.
received_close_notify: bool,
/// By default, reaching the end-of-stream when reading from the server will
/// cause `error.TlsConnectionTruncated` to be returned, unless a close_notify
/// message has been received. By setting this flag to `true`, instead, the
/// end-of-stream will be forwarded to the application layer above TLS.
/// This makes the application vulnerable to truncation attacks unless the
/// application layer itself verifies that the amount of data received equals
/// the amount of data expected, such as HTTP with the Content-Length header.
allow_truncation_attacks: bool = false,
application_cipher: tls.ApplicationCipher,
/// The size is enough to contain exactly one TLSCiphertext record.
/// This buffer is segmented into four parts:
/// 0. unused
/// 1. cleartext
/// 2. ciphertext
/// 3. unused
/// The fields `partial_cleartext_idx`, `partial_ciphertext_idx`, and
/// `partial_ciphertext_end` describe the span of the segments.
partially_read_buffer: [tls.max_ciphertext_record_len]u8,
/// This is an example of the type that is needed by the read and write
/// functions. It can have any fields but it must at least have these
/// functions.
///
/// Note that `std.net.Stream` conforms to this interface.
///
/// This declaration serves as documentation only.
pub const StreamInterface = struct {
/// Can be any error set.
pub const ReadError = error{};
/// Returns the number of bytes read. The number read may be less than the
/// buffer space provided. End-of-stream is indicated by a return value of 0.
///
/// The `iovecs` parameter is mutable because so that function may to
/// mutate the fields in order to handle partial reads from the underlying
/// stream layer.
pub fn readv(this: @This(), iovecs: []std.os.iovec) ReadError!usize {
_ = .{ this, iovecs };
@panic("unimplemented");
}
/// Can be any error set.
pub const WriteError = error{};
/// Returns the number of bytes read, which may be less than the buffer
/// space provided. A short read does not indicate end-of-stream.
pub fn writev(this: @This(), iovecs: []const std.os.iovec_const) WriteError!usize {
_ = .{ this, iovecs };
@panic("unimplemented");
}
/// Returns the number of bytes read, which may be less than the buffer
/// space provided, indicating end-of-stream.
/// The `iovecs` parameter is mutable in case this function needs to mutate
/// the fields in order to handle partial writes from the underlying layer.
pub fn writevAll(this: @This(), iovecs: []std.os.iovec_const) WriteError!usize {
// This can be implemented in terms of writev, or specialized if desired.
_ = .{ this, iovecs };
@panic("unimplemented");
}
};
pub fn InitError(comptime Stream: type) type {
return std.mem.Allocator.Error || Stream.WriteError || Stream.ReadError || tls.AlertDescription.Error || error{
InsufficientEntropy,
DiskQuota,
LockViolation,
NotOpenForWriting,
TlsUnexpectedMessage,
TlsIllegalParameter,
TlsDecryptFailure,
TlsRecordOverflow,
TlsBadRecordMac,
CertificateFieldHasInvalidLength,
CertificateHostMismatch,
CertificatePublicKeyInvalid,
CertificateExpired,
CertificateFieldHasWrongDataType,
CertificateIssuerMismatch,
CertificateNotYetValid,
CertificateSignatureAlgorithmMismatch,
CertificateSignatureAlgorithmUnsupported,
CertificateSignatureInvalid,
CertificateSignatureInvalidLength,
CertificateSignatureNamedCurveUnsupported,
CertificateSignatureUnsupportedBitCount,
TlsCertificateNotVerified,
TlsBadSignatureScheme,
TlsBadRsaSignatureBitCount,
InvalidEncoding,
IdentityElement,
SignatureVerificationFailed,
TlsDecryptError,
TlsConnectionTruncated,
TlsDecodeError,
UnsupportedCertificateVersion,
CertificateTimeInvalid,
CertificateHasUnrecognizedObjectId,
CertificateHasInvalidBitString,
MessageTooLong,
NegativeIntoUnsigned,
TargetTooSmall,
BufferTooSmall,
InvalidSignature,
NotSquare,
NonCanonical,
WeakPublicKey,
};
}
/// Initiates a TLS handshake and establishes a TLSv1.3 session with `stream`, which
/// must conform to `StreamInterface`.
///
/// `host` is only borrowed during this function call.
pub fn init(stream: anytype, ca_bundle: Certificate.Bundle, host: []const u8) InitError(@TypeOf(stream))!Client {
const host_len: u16 = @intCast(host.len);
var random_buffer: [128]u8 = undefined;
crypto.random.bytes(&random_buffer);
const hello_rand = random_buffer[0..32].*;
const legacy_session_id = random_buffer[32..64].*;
const x25519_kp_seed = random_buffer[64..96].*;
const secp256r1_kp_seed = random_buffer[96..128].*;
const x25519_kp = crypto.dh.X25519.KeyPair.create(x25519_kp_seed) catch |err| switch (err) {
// Only possible to happen if the private key is all zeroes.
error.IdentityElement => return error.InsufficientEntropy,
};
const secp256r1_kp = crypto.sign.ecdsa.EcdsaP256Sha256.KeyPair.create(secp256r1_kp_seed) catch |err| switch (err) {
// Only possible to happen if the private key is all zeroes.
error.IdentityElement => return error.InsufficientEntropy,
};
const kyber768_kp = crypto.kem.kyber_d00.Kyber768.KeyPair.create(null) catch {};
const extensions_payload =
tls.extension(.supported_versions, [_]u8{
0x02, // byte length of supported versions
0x03, 0x04, // TLS 1.3
}) ++ tls.extension(.signature_algorithms, enum_array(tls.SignatureScheme, &.{
.ecdsa_secp256r1_sha256,
.ecdsa_secp384r1_sha384,
.rsa_pss_rsae_sha256,
.rsa_pss_rsae_sha384,
.rsa_pss_rsae_sha512,
.ed25519,
})) ++ tls.extension(.supported_groups, enum_array(tls.NamedGroup, &.{
.x25519_kyber768d00,
.secp256r1,
.x25519,
})) ++ tls.extension(
.key_share,
array(1, int2(@intFromEnum(tls.NamedGroup.x25519)) ++
array(1, x25519_kp.public_key) ++
int2(@intFromEnum(tls.NamedGroup.secp256r1)) ++
array(1, secp256r1_kp.public_key.toUncompressedSec1()) ++
int2(@intFromEnum(tls.NamedGroup.x25519_kyber768d00)) ++
array(1, x25519_kp.public_key ++ kyber768_kp.public_key.toBytes())),
) ++
int2(@intFromEnum(tls.ExtensionType.server_name)) ++
int2(host_len + 5) ++ // byte length of this extension payload
int2(host_len + 3) ++ // server_name_list byte count
[1]u8{0x00} ++ // name_type
int2(host_len);
const extensions_header =
int2(@intCast(extensions_payload.len + host_len)) ++
extensions_payload;
const legacy_compression_methods = 0x0100;
const client_hello =
int2(@intFromEnum(tls.ProtocolVersion.tls_1_2)) ++
hello_rand ++
[1]u8{32} ++ legacy_session_id ++
cipher_suites ++
int2(legacy_compression_methods) ++
extensions_header;
const out_handshake =
[_]u8{@intFromEnum(tls.HandshakeType.client_hello)} ++
int3(@intCast(client_hello.len + host_len)) ++
client_hello;
const plaintext_header = [_]u8{
@intFromEnum(tls.ContentType.handshake),
0x03, 0x01, // legacy_record_version
} ++ int2(@intCast(out_handshake.len + host_len)) ++ out_handshake;
{
var iovecs = [_]std.os.iovec_const{
.{
.iov_base = &plaintext_header,
.iov_len = plaintext_header.len,
},
.{
.iov_base = host.ptr,
.iov_len = host.len,
},
};
try stream.writevAll(&iovecs);
}
const client_hello_bytes1 = plaintext_header[5..];
var handshake_cipher: tls.HandshakeCipher = undefined;
var handshake_buffer: [8000]u8 = undefined;
var d: tls.Decoder = .{ .buf = &handshake_buffer };
{
try d.readAtLeastOurAmt(stream, tls.record_header_len);
const ct = d.decode(tls.ContentType);
d.skip(2); // legacy_record_version
const record_len = d.decode(u16);
try d.readAtLeast(stream, record_len);
const server_hello_fragment = d.buf[d.idx..][0..record_len];
var ptd = try d.sub(record_len);
switch (ct) {
.alert => {
try ptd.ensure(2);
const level = ptd.decode(tls.AlertLevel);
const desc = ptd.decode(tls.AlertDescription);
_ = level;
// if this isn't a error alert, then it's a closure alert, which makes no sense in a handshake
try desc.toError();
// TODO: handle server-side closures
return error.TlsUnexpectedMessage;
},
.handshake => {
try ptd.ensure(4);
const handshake_type = ptd.decode(tls.HandshakeType);
if (handshake_type != .server_hello) return error.TlsUnexpectedMessage;
const length = ptd.decode(u24);
var hsd = try ptd.sub(length);
try hsd.ensure(2 + 32 + 1 + 32 + 2 + 1 + 2);
const legacy_version = hsd.decode(u16);
const random = hsd.array(32);
if (mem.eql(u8, random, &tls.hello_retry_request_sequence)) {
// This is a HelloRetryRequest message. This client implementation
// does not expect to get one.
return error.TlsUnexpectedMessage;
}
const legacy_session_id_echo_len = hsd.decode(u8);
if (legacy_session_id_echo_len != 32) return error.TlsIllegalParameter;
const legacy_session_id_echo = hsd.array(32);
if (!mem.eql(u8, legacy_session_id_echo, &legacy_session_id))
return error.TlsIllegalParameter;
const cipher_suite_tag = hsd.decode(tls.CipherSuite);
hsd.skip(1); // legacy_compression_method
const extensions_size = hsd.decode(u16);
var all_extd = try hsd.sub(extensions_size);
var supported_version: u16 = 0;
var shared_key: []const u8 = undefined;
var have_shared_key = false;
while (!all_extd.eof()) {
try all_extd.ensure(2 + 2);
const et = all_extd.decode(tls.ExtensionType);
const ext_size = all_extd.decode(u16);
var extd = try all_extd.sub(ext_size);
switch (et) {
.supported_versions => {
if (supported_version != 0) return error.TlsIllegalParameter;
try extd.ensure(2);
supported_version = extd.decode(u16);
},
.key_share => {
if (have_shared_key) return error.TlsIllegalParameter;
have_shared_key = true;
try extd.ensure(4);
const named_group = extd.decode(tls.NamedGroup);
const key_size = extd.decode(u16);
try extd.ensure(key_size);
switch (named_group) {
.x25519_kyber768d00 => {
const xksl = crypto.dh.X25519.public_length;
const hksl = xksl + crypto.kem.kyber_d00.Kyber768.ciphertext_length;
if (key_size != hksl)
return error.TlsIllegalParameter;
const server_ks = extd.array(hksl);
shared_key = &((crypto.dh.X25519.scalarmult(
x25519_kp.secret_key,
server_ks[0..xksl].*,
) catch return error.TlsDecryptFailure) ++ (kyber768_kp.secret_key.decaps(
server_ks[xksl..hksl],
) catch return error.TlsDecryptFailure));
},
.x25519 => {
const ksl = crypto.dh.X25519.public_length;
if (key_size != ksl) return error.TlsIllegalParameter;
const server_pub_key = extd.array(ksl);
shared_key = &(crypto.dh.X25519.scalarmult(
x25519_kp.secret_key,
server_pub_key.*,
) catch return error.TlsDecryptFailure);
},
.secp256r1 => {
const server_pub_key = extd.slice(key_size);
const PublicKey = crypto.sign.ecdsa.EcdsaP256Sha256.PublicKey;
const pk = PublicKey.fromSec1(server_pub_key) catch {
return error.TlsDecryptFailure;
};
const mul = pk.p.mulPublic(secp256r1_kp.secret_key.bytes, .big) catch {
return error.TlsDecryptFailure;
};
shared_key = &mul.affineCoordinates().x.toBytes(.big);
},
else => {
return error.TlsIllegalParameter;
},
}
},
else => {},
}
}
if (!have_shared_key) return error.TlsIllegalParameter;
const tls_version = if (supported_version == 0) legacy_version else supported_version;
if (tls_version != @intFromEnum(tls.ProtocolVersion.tls_1_3))
return error.TlsIllegalParameter;
switch (cipher_suite_tag) {
inline .AES_128_GCM_SHA256,
.AES_256_GCM_SHA384,
.CHACHA20_POLY1305_SHA256,
.AEGIS_256_SHA512,
.AEGIS_128L_SHA256,
=> |tag| {
const P = std.meta.TagPayloadByName(tls.HandshakeCipher, @tagName(tag));
handshake_cipher = @unionInit(tls.HandshakeCipher, @tagName(tag), .{
.handshake_secret = undefined,
.master_secret = undefined,
.client_handshake_key = undefined,
.server_handshake_key = undefined,
.client_finished_key = undefined,
.server_finished_key = undefined,
.client_handshake_iv = undefined,
.server_handshake_iv = undefined,
.transcript_hash = P.Hash.init(.{}),
});
const p = &@field(handshake_cipher, @tagName(tag));
p.transcript_hash.update(client_hello_bytes1); // Client Hello part 1
p.transcript_hash.update(host); // Client Hello part 2
p.transcript_hash.update(server_hello_fragment);
const hello_hash = p.transcript_hash.peek();
const zeroes = [1]u8{0} ** P.Hash.digest_length;
const early_secret = P.Hkdf.extract(&[1]u8{0}, &zeroes);
const empty_hash = tls.emptyHash(P.Hash);
const hs_derived_secret = hkdfExpandLabel(P.Hkdf, early_secret, "derived", &empty_hash, P.Hash.digest_length);
p.handshake_secret = P.Hkdf.extract(&hs_derived_secret, shared_key);
const ap_derived_secret = hkdfExpandLabel(P.Hkdf, p.handshake_secret, "derived", &empty_hash, P.Hash.digest_length);
p.master_secret = P.Hkdf.extract(&ap_derived_secret, &zeroes);
const client_secret = hkdfExpandLabel(P.Hkdf, p.handshake_secret, "c hs traffic", &hello_hash, P.Hash.digest_length);
const server_secret = hkdfExpandLabel(P.Hkdf, p.handshake_secret, "s hs traffic", &hello_hash, P.Hash.digest_length);
p.client_finished_key = hkdfExpandLabel(P.Hkdf, client_secret, "finished", "", P.Hmac.key_length);
p.server_finished_key = hkdfExpandLabel(P.Hkdf, server_secret, "finished", "", P.Hmac.key_length);
p.client_handshake_key = hkdfExpandLabel(P.Hkdf, client_secret, "key", "", P.AEAD.key_length);
p.server_handshake_key = hkdfExpandLabel(P.Hkdf, server_secret, "key", "", P.AEAD.key_length);
p.client_handshake_iv = hkdfExpandLabel(P.Hkdf, client_secret, "iv", "", P.AEAD.nonce_length);
p.server_handshake_iv = hkdfExpandLabel(P.Hkdf, server_secret, "iv", "", P.AEAD.nonce_length);
},
else => {
return error.TlsIllegalParameter;
},
}
},
else => return error.TlsUnexpectedMessage,
}
}
// This is used for two purposes:
// * Detect whether a certificate is the first one presented, in which case
// we need to verify the host name.
// * Flip back and forth between the two cleartext buffers in order to keep
// the previous certificate in memory so that it can be verified by the
// next one.
var cert_index: usize = 0;
var read_seq: u64 = 0;
var prev_cert: Certificate.Parsed = undefined;
// Set to true once a trust chain has been established from the first
// certificate to a root CA.
const HandshakeState = enum {
/// In this state we expect only an encrypted_extensions message.
encrypted_extensions,
/// In this state we expect certificate messages.
certificate,
/// In this state we expect certificate or certificate_verify messages.
/// certificate messages are ignored since the trust chain is already
/// established.
trust_chain_established,
/// In this state, we expect only the finished message.
finished,
};
var handshake_state: HandshakeState = .encrypted_extensions;
var cleartext_bufs: [2][8000]u8 = undefined;
var main_cert_pub_key_algo: Certificate.AlgorithmCategory = undefined;
var main_cert_pub_key_buf: [600]u8 = undefined;
var main_cert_pub_key_len: u16 = undefined;
const now_sec = std.time.timestamp();
while (true) {
try d.readAtLeastOurAmt(stream, tls.record_header_len);
const record_header = d.buf[d.idx..][0..5];
const ct = d.decode(tls.ContentType);
d.skip(2); // legacy_version
const record_len = d.decode(u16);
try d.readAtLeast(stream, record_len);
var record_decoder = try d.sub(record_len);
switch (ct) {
.change_cipher_spec => {
try record_decoder.ensure(1);
if (record_decoder.decode(u8) != 0x01) return error.TlsIllegalParameter;
},
.application_data => {
const cleartext_buf = &cleartext_bufs[cert_index % 2];
const cleartext = switch (handshake_cipher) {
inline else => |*p| c: {
const P = @TypeOf(p.*);
const ciphertext_len = record_len - P.AEAD.tag_length;
try record_decoder.ensure(ciphertext_len + P.AEAD.tag_length);
const ciphertext = record_decoder.slice(ciphertext_len);
if (ciphertext.len > cleartext_buf.len) return error.TlsRecordOverflow;
const cleartext = cleartext_buf[0..ciphertext.len];
const auth_tag = record_decoder.array(P.AEAD.tag_length).*;
const nonce = if (builtin.zig_backend == .stage2_x86_64 and
P.AEAD.nonce_length > comptime std.simd.suggestVectorLength(u8) orelse 1)
nonce: {
var nonce = p.server_handshake_iv;
const operand = std.mem.readInt(u64, nonce[nonce.len - 8 ..], .big);
std.mem.writeInt(u64, nonce[nonce.len - 8 ..], operand ^ read_seq, .big);
break :nonce nonce;
} else nonce: {
const V = @Vector(P.AEAD.nonce_length, u8);
const pad = [1]u8{0} ** (P.AEAD.nonce_length - 8);
const operand: V = pad ++ @as([8]u8, @bitCast(big(read_seq)));
break :nonce @as(V, p.server_handshake_iv) ^ operand;
};
read_seq += 1;
P.AEAD.decrypt(cleartext, ciphertext, auth_tag, record_header, nonce, p.server_handshake_key) catch
return error.TlsBadRecordMac;
break :c cleartext;
},
};
const inner_ct: tls.ContentType = @enumFromInt(cleartext[cleartext.len - 1]);
if (inner_ct != .handshake) return error.TlsUnexpectedMessage;
var ctd = tls.Decoder.fromTheirSlice(cleartext[0 .. cleartext.len - 1]);
while (true) {
try ctd.ensure(4);
const handshake_type = ctd.decode(tls.HandshakeType);
const handshake_len = ctd.decode(u24);
var hsd = try ctd.sub(handshake_len);
const wrapped_handshake = ctd.buf[ctd.idx - handshake_len - 4 .. ctd.idx];
const handshake = ctd.buf[ctd.idx - handshake_len .. ctd.idx];
switch (handshake_type) {
.encrypted_extensions => {
if (handshake_state != .encrypted_extensions) return error.TlsUnexpectedMessage;
handshake_state = .certificate;
switch (handshake_cipher) {
inline else => |*p| p.transcript_hash.update(wrapped_handshake),
}
try hsd.ensure(2);
const total_ext_size = hsd.decode(u16);
var all_extd = try hsd.sub(total_ext_size);
while (!all_extd.eof()) {
try all_extd.ensure(4);
const et = all_extd.decode(tls.ExtensionType);
const ext_size = all_extd.decode(u16);
const extd = try all_extd.sub(ext_size);
_ = extd;
switch (et) {
.server_name => {},
else => {},
}
}
},
.certificate => cert: {
switch (handshake_cipher) {
inline else => |*p| p.transcript_hash.update(wrapped_handshake),
}
switch (handshake_state) {
.certificate => {},
.trust_chain_established => break :cert,
else => return error.TlsUnexpectedMessage,
}
try hsd.ensure(1 + 4);
const cert_req_ctx_len = hsd.decode(u8);
if (cert_req_ctx_len != 0) return error.TlsIllegalParameter;
const certs_size = hsd.decode(u24);
var certs_decoder = try hsd.sub(certs_size);
while (!certs_decoder.eof()) {
try certs_decoder.ensure(3);
const cert_size = certs_decoder.decode(u24);
const certd = try certs_decoder.sub(cert_size);
const subject_cert: Certificate = .{
.buffer = certd.buf,
.index = @intCast(certd.idx),
};
const subject = try subject_cert.parse();
if (cert_index == 0) {
// Verify the host on the first certificate.
try subject.verifyHostName(host);
// Keep track of the public key for the
// certificate_verify message later.
main_cert_pub_key_algo = subject.pub_key_algo;
const pub_key = subject.pubKey();
if (pub_key.len > main_cert_pub_key_buf.len)
return error.CertificatePublicKeyInvalid;
@memcpy(main_cert_pub_key_buf[0..pub_key.len], pub_key);
main_cert_pub_key_len = @intCast(pub_key.len);
} else {
try prev_cert.verify(subject, now_sec);
}
if (ca_bundle.verify(subject, now_sec)) |_| {
handshake_state = .trust_chain_established;
break :cert;
} else |err| switch (err) {
error.CertificateIssuerNotFound => {},
else => |e| return e,
}
prev_cert = subject;
cert_index += 1;
try certs_decoder.ensure(2);
const total_ext_size = certs_decoder.decode(u16);
const all_extd = try certs_decoder.sub(total_ext_size);
_ = all_extd;
}
},
.certificate_verify => {
switch (handshake_state) {
.trust_chain_established => handshake_state = .finished,
.certificate => return error.TlsCertificateNotVerified,
else => return error.TlsUnexpectedMessage,
}
try hsd.ensure(4);
const scheme = hsd.decode(tls.SignatureScheme);
const sig_len = hsd.decode(u16);
try hsd.ensure(sig_len);
const encoded_sig = hsd.slice(sig_len);
const max_digest_len = 64;
var verify_buffer: [64 + 34 + max_digest_len]u8 =
([1]u8{0x20} ** 64) ++
"TLS 1.3, server CertificateVerify\x00".* ++
@as([max_digest_len]u8, undefined);
const verify_bytes = switch (handshake_cipher) {
inline else => |*p| v: {
const transcript_digest = p.transcript_hash.peek();
verify_buffer[verify_buffer.len - max_digest_len ..][0..transcript_digest.len].* = transcript_digest;
p.transcript_hash.update(wrapped_handshake);
break :v verify_buffer[0 .. verify_buffer.len - max_digest_len + transcript_digest.len];
},
};
const main_cert_pub_key = main_cert_pub_key_buf[0..main_cert_pub_key_len];
switch (scheme) {
inline .ecdsa_secp256r1_sha256,
.ecdsa_secp384r1_sha384,
=> |comptime_scheme| {
if (main_cert_pub_key_algo != .X9_62_id_ecPublicKey)
return error.TlsBadSignatureScheme;
const Ecdsa = SchemeEcdsa(comptime_scheme);
const sig = try Ecdsa.Signature.fromDer(encoded_sig);
const key = try Ecdsa.PublicKey.fromSec1(main_cert_pub_key);
try sig.verify(verify_bytes, key);
},
inline .rsa_pss_rsae_sha256,
.rsa_pss_rsae_sha384,
.rsa_pss_rsae_sha512,
=> |comptime_scheme| {
if (main_cert_pub_key_algo != .rsaEncryption)
return error.TlsBadSignatureScheme;
const Hash = SchemeHash(comptime_scheme);
const rsa = Certificate.rsa;
const components = try rsa.PublicKey.parseDer(main_cert_pub_key);
const exponent = components.exponent;
const modulus = components.modulus;
switch (modulus.len) {
inline 128, 256, 512 => |modulus_len| {
const key = try rsa.PublicKey.fromBytes(exponent, modulus);
const sig = rsa.PSSSignature.fromBytes(modulus_len, encoded_sig);
try rsa.PSSSignature.verify(modulus_len, sig, verify_bytes, key, Hash);
},
else => {
return error.TlsBadRsaSignatureBitCount;
},
}
},
inline .ed25519 => |comptime_scheme| {
if (main_cert_pub_key_algo != .curveEd25519) return error.TlsBadSignatureScheme;
const Eddsa = SchemeEddsa(comptime_scheme);
if (encoded_sig.len != Eddsa.Signature.encoded_length) return error.InvalidEncoding;
const sig = Eddsa.Signature.fromBytes(encoded_sig[0..Eddsa.Signature.encoded_length].*);
if (main_cert_pub_key.len != Eddsa.PublicKey.encoded_length) return error.InvalidEncoding;
const key = try Eddsa.PublicKey.fromBytes(main_cert_pub_key[0..Eddsa.PublicKey.encoded_length].*);
try sig.verify(verify_bytes, key);
},
else => {
return error.TlsBadSignatureScheme;
},
}
},
.finished => {
if (handshake_state != .finished) return error.TlsUnexpectedMessage;
// This message is to trick buggy proxies into behaving correctly.
const client_change_cipher_spec_msg = [_]u8{
@intFromEnum(tls.ContentType.change_cipher_spec),
0x03, 0x03, // legacy protocol version
0x00, 0x01, // length
0x01,
};
const app_cipher = switch (handshake_cipher) {
inline else => |*p, tag| c: {
const P = @TypeOf(p.*);
const finished_digest = p.transcript_hash.peek();
p.transcript_hash.update(wrapped_handshake);
const expected_server_verify_data = tls.hmac(P.Hmac, &finished_digest, p.server_finished_key);
if (!mem.eql(u8, &expected_server_verify_data, handshake))
return error.TlsDecryptError;
const handshake_hash = p.transcript_hash.finalResult();
const verify_data = tls.hmac(P.Hmac, &handshake_hash, p.client_finished_key);
const out_cleartext = [_]u8{
@intFromEnum(tls.HandshakeType.finished),
0, 0, verify_data.len, // length
} ++ verify_data ++ [1]u8{@intFromEnum(tls.ContentType.handshake)};
const wrapped_len = out_cleartext.len + P.AEAD.tag_length;
var finished_msg = [_]u8{
@intFromEnum(tls.ContentType.application_data),
0x03, 0x03, // legacy protocol version
0, wrapped_len, // byte length of encrypted record
} ++ @as([wrapped_len]u8, undefined);
const ad = finished_msg[0..5];
const ciphertext = finished_msg[5..][0..out_cleartext.len];
const auth_tag = finished_msg[finished_msg.len - P.AEAD.tag_length ..];
const nonce = p.client_handshake_iv;
P.AEAD.encrypt(ciphertext, auth_tag, &out_cleartext, ad, nonce, p.client_handshake_key);
const both_msgs = client_change_cipher_spec_msg ++ finished_msg;
var both_msgs_vec = [_]std.os.iovec_const{.{
.iov_base = &both_msgs,
.iov_len = both_msgs.len,
}};
try stream.writevAll(&both_msgs_vec);
const client_secret = hkdfExpandLabel(P.Hkdf, p.master_secret, "c ap traffic", &handshake_hash, P.Hash.digest_length);
const server_secret = hkdfExpandLabel(P.Hkdf, p.master_secret, "s ap traffic", &handshake_hash, P.Hash.digest_length);
break :c @unionInit(tls.ApplicationCipher, @tagName(tag), .{
.client_secret = client_secret,
.server_secret = server_secret,
.client_key = hkdfExpandLabel(P.Hkdf, client_secret, "key", "", P.AEAD.key_length),
.server_key = hkdfExpandLabel(P.Hkdf, server_secret, "key", "", P.AEAD.key_length),
.client_iv = hkdfExpandLabel(P.Hkdf, client_secret, "iv", "", P.AEAD.nonce_length),
.server_iv = hkdfExpandLabel(P.Hkdf, server_secret, "iv", "", P.AEAD.nonce_length),
});
},
};
const leftover = d.rest();
var client: Client = .{
.read_seq = 0,
.write_seq = 0,
.partial_cleartext_idx = 0,
.partial_ciphertext_idx = 0,
.partial_ciphertext_end = @intCast(leftover.len),
.received_close_notify = false,
.application_cipher = app_cipher,
.partially_read_buffer = undefined,
};
@memcpy(client.partially_read_buffer[0..leftover.len], leftover);
return client;
},
else => {
return error.TlsUnexpectedMessage;
},
}
if (ctd.eof()) break;
}
},
else => {
return error.TlsUnexpectedMessage;
},
}
}
}
/// Sends TLS-encrypted data to `stream`, which must conform to `StreamInterface`.
/// Returns the number of plaintext bytes sent, which may be fewer than `bytes.len`.
pub fn write(c: *Client, stream: anytype, bytes: []const u8) !usize {
return writeEnd(c, stream, bytes, false);
}
/// Sends TLS-encrypted data to `stream`, which must conform to `StreamInterface`.
pub fn writeAll(c: *Client, stream: anytype, bytes: []const u8) !void {
var index: usize = 0;
while (index < bytes.len) {
index += try c.write(stream, bytes[index..]);
}
}
/// Sends TLS-encrypted data to `stream`, which must conform to `StreamInterface`.
/// If `end` is true, then this function additionally sends a `close_notify` alert,
/// which is necessary for the server to distinguish between a properly finished
/// TLS session, or a truncation attack.
pub fn writeAllEnd(c: *Client, stream: anytype, bytes: []const u8, end: bool) !void {
var index: usize = 0;
while (index < bytes.len) {
index += try c.writeEnd(stream, bytes[index..], end);
}
}
/// Sends TLS-encrypted data to `stream`, which must conform to `StreamInterface`.
/// Returns the number of plaintext bytes sent, which may be fewer than `bytes.len`.
/// If `end` is true, then this function additionally sends a `close_notify` alert,
/// which is necessary for the server to distinguish between a properly finished
/// TLS session, or a truncation attack.
pub fn writeEnd(c: *Client, stream: anytype, bytes: []const u8, end: bool) !usize {
var ciphertext_buf: [tls.max_ciphertext_record_len * 4]u8 = undefined;
var iovecs_buf: [6]std.os.iovec_const = undefined;
var prepared = prepareCiphertextRecord(c, &iovecs_buf, &ciphertext_buf, bytes, .application_data);
if (end) {
prepared.iovec_end += prepareCiphertextRecord(
c,
iovecs_buf[prepared.iovec_end..],
ciphertext_buf[prepared.ciphertext_end..],
&tls.close_notify_alert,
.alert,
).iovec_end;
}
const iovec_end = prepared.iovec_end;
const overhead_len = prepared.overhead_len;
// Ideally we would call writev exactly once here, however, we must ensure
// that we don't return with a record partially written.
var i: usize = 0;
var total_amt: usize = 0;
while (true) {
var amt = try stream.writev(iovecs_buf[i..iovec_end]);
while (amt >= iovecs_buf[i].iov_len) {
const encrypted_amt = iovecs_buf[i].iov_len;
total_amt += encrypted_amt - overhead_len;
amt -= encrypted_amt;
i += 1;
// Rely on the property that iovecs delineate records, meaning that
// if amt equals zero here, we have fortunately found ourselves
// with a short read that aligns at the record boundary.
if (i >= iovec_end) return total_amt;
// We also cannot return on a vector boundary if the final close_notify is
// not sent; otherwise the caller would not know to retry the call.
if (amt == 0 and (!end or i < iovec_end - 1)) return total_amt;
}
iovecs_buf[i].iov_base += amt;
iovecs_buf[i].iov_len -= amt;
}
}
fn prepareCiphertextRecord(
c: *Client,
iovecs: []std.os.iovec_const,
ciphertext_buf: []u8,
bytes: []const u8,
inner_content_type: tls.ContentType,
) struct {
iovec_end: usize,
ciphertext_end: usize,
/// How many bytes are taken up by overhead per record.
overhead_len: usize,
} {
// Due to the trailing inner content type byte in the ciphertext, we need
// an additional buffer for storing the cleartext into before encrypting.
var cleartext_buf: [max_ciphertext_len]u8 = undefined;
var ciphertext_end: usize = 0;
var iovec_end: usize = 0;
var bytes_i: usize = 0;
switch (c.application_cipher) {
inline else => |*p| {
const P = @TypeOf(p.*);
const overhead_len = tls.record_header_len + P.AEAD.tag_length + 1;
const close_notify_alert_reserved = tls.close_notify_alert.len + overhead_len;
while (true) {
const encrypted_content_len: u16 = @intCast(@min(
@min(bytes.len - bytes_i, tls.max_cipertext_inner_record_len),
ciphertext_buf.len -|
(close_notify_alert_reserved + overhead_len + ciphertext_end),
));
if (encrypted_content_len == 0) return .{
.iovec_end = iovec_end,
.ciphertext_end = ciphertext_end,
.overhead_len = overhead_len,
};
@memcpy(cleartext_buf[0..encrypted_content_len], bytes[bytes_i..][0..encrypted_content_len]);
cleartext_buf[encrypted_content_len] = @intFromEnum(inner_content_type);
bytes_i += encrypted_content_len;
const ciphertext_len = encrypted_content_len + 1;
const cleartext = cleartext_buf[0..ciphertext_len];
const record_start = ciphertext_end;
const ad = ciphertext_buf[ciphertext_end..][0..5];
ad.* =
[_]u8{@intFromEnum(tls.ContentType.application_data)} ++
int2(@intFromEnum(tls.ProtocolVersion.tls_1_2)) ++
int2(ciphertext_len + P.AEAD.tag_length);
ciphertext_end += ad.len;
const ciphertext = ciphertext_buf[ciphertext_end..][0..ciphertext_len];
ciphertext_end += ciphertext_len;
const auth_tag = ciphertext_buf[ciphertext_end..][0..P.AEAD.tag_length];
ciphertext_end += auth_tag.len;
const nonce = if (builtin.zig_backend == .stage2_x86_64 and
P.AEAD.nonce_length > comptime std.simd.suggestVectorLength(u8) orelse 1)
nonce: {
var nonce = p.client_iv;
const operand = std.mem.readInt(u64, nonce[nonce.len - 8 ..], .big);
std.mem.writeInt(u64, nonce[nonce.len - 8 ..], operand ^ c.write_seq, .big);
break :nonce nonce;
} else nonce: {
const V = @Vector(P.AEAD.nonce_length, u8);
const pad = [1]u8{0} ** (P.AEAD.nonce_length - 8);
const operand: V = pad ++ @as([8]u8, @bitCast(big(c.write_seq)));
break :nonce @as(V, p.client_iv) ^ operand;
};
c.write_seq += 1; // TODO send key_update on overflow
P.AEAD.encrypt(ciphertext, auth_tag, cleartext, ad, nonce, p.client_key);
const record = ciphertext_buf[record_start..ciphertext_end];
iovecs[iovec_end] = .{
.iov_base = record.ptr,
.iov_len = record.len,
};
iovec_end += 1;
}
},
}
}
pub fn eof(c: Client) bool {
return c.received_close_notify and
c.partial_cleartext_idx >= c.partial_ciphertext_idx and
c.partial_ciphertext_idx >= c.partial_ciphertext_end;
}
/// Receives TLS-encrypted data from `stream`, which must conform to `StreamInterface`.
/// Returns the number of bytes read, calling the underlying read function the
/// minimal number of times until the buffer has at least `len` bytes filled.
/// If the number read is less than `len` it means the stream reached the end.
/// Reaching the end of the stream is not an error condition.
pub fn readAtLeast(c: *Client, stream: anytype, buffer: []u8, len: usize) !usize {
var iovecs = [1]std.os.iovec{.{ .iov_base = buffer.ptr, .iov_len = buffer.len }};
return readvAtLeast(c, stream, &iovecs, len);
}
/// Receives TLS-encrypted data from `stream`, which must conform to `StreamInterface`.
pub fn read(c: *Client, stream: anytype, buffer: []u8) !usize {
return readAtLeast(c, stream, buffer, 1);
}
/// Receives TLS-encrypted data from `stream`, which must conform to `StreamInterface`.
/// Returns the number of bytes read. If the number read is smaller than
/// `buffer.len`, it means the stream reached the end. Reaching the end of the
/// stream is not an error condition.
pub fn readAll(c: *Client, stream: anytype, buffer: []u8) !usize {
return readAtLeast(c, stream, buffer, buffer.len);
}
/// Receives TLS-encrypted data from `stream`, which must conform to `StreamInterface`.
/// Returns the number of bytes read. If the number read is less than the space
/// provided it means the stream reached the end. Reaching the end of the
/// stream is not an error condition.
/// The `iovecs` parameter is mutable because this function needs to mutate the fields in
/// order to handle partial reads from the underlying stream layer.
pub fn readv(c: *Client, stream: anytype, iovecs: []std.os.iovec) !usize {
return readvAtLeast(c, stream, iovecs, 1);
}
/// Receives TLS-encrypted data from `stream`, which must conform to `StreamInterface`.
/// Returns the number of bytes read, calling the underlying read function the
/// minimal number of times until the iovecs have at least `len` bytes filled.
/// If the number read is less than `len` it means the stream reached the end.
/// Reaching the end of the stream is not an error condition.
/// The `iovecs` parameter is mutable because this function needs to mutate the fields in
/// order to handle partial reads from the underlying stream layer.
pub fn readvAtLeast(c: *Client, stream: anytype, iovecs: []std.os.iovec, len: usize) !usize {
if (c.eof()) return 0;
var off_i: usize = 0;
var vec_i: usize = 0;
while (true) {
var amt = try c.readvAdvanced(stream, iovecs[vec_i..]);
off_i += amt;
if (c.eof() or off_i >= len) return off_i;
while (amt >= iovecs[vec_i].iov_len) {
amt -= iovecs[vec_i].iov_len;
vec_i += 1;
}
iovecs[vec_i].iov_base += amt;
iovecs[vec_i].iov_len -= amt;
}
}
/// Receives TLS-encrypted data from `stream`, which must conform to `StreamInterface`.
/// Returns number of bytes that have been read, populated inside `iovecs`. A
/// return value of zero bytes does not mean end of stream. Instead, check the `eof()`
/// for the end of stream. The `eof()` may be true after any call to
/// `read`, including when greater than zero bytes are returned, and this
/// function asserts that `eof()` is `false`.
/// See `readv` for a higher level function that has the same, familiar API as
/// other read functions, such as `std.fs.File.read`.
pub fn readvAdvanced(c: *Client, stream: anytype, iovecs: []const std.os.iovec) !usize {
var vp: VecPut = .{ .iovecs = iovecs };
// Give away the buffered cleartext we have, if any.
const partial_cleartext = c.partially_read_buffer[c.partial_cleartext_idx..c.partial_ciphertext_idx];
if (partial_cleartext.len > 0) {
const amt: u15 = @intCast(vp.put(partial_cleartext));
c.partial_cleartext_idx += amt;
if (c.partial_cleartext_idx == c.partial_ciphertext_idx and
c.partial_ciphertext_end == c.partial_ciphertext_idx)
{
// The buffer is now empty.
c.partial_cleartext_idx = 0;
c.partial_ciphertext_idx = 0;
c.partial_ciphertext_end = 0;
}
if (c.received_close_notify) {
c.partial_ciphertext_end = 0;
assert(vp.total == amt);
return amt;
} else if (amt > 0) {
// We don't need more data, so don't call read.
assert(vp.total == amt);
return amt;
}
}
assert(!c.received_close_notify);
// Ideally, this buffer would never be used. It is needed when `iovecs` are
// too small to fit the cleartext, which may be as large as `max_ciphertext_len`.
var cleartext_stack_buffer: [max_ciphertext_len]u8 = undefined;
// Temporarily stores ciphertext before decrypting it and giving it to `iovecs`.
var in_stack_buffer: [max_ciphertext_len * 4]u8 = undefined;
// How many bytes left in the user's buffer.
const free_size = vp.freeSize();
// The amount of the user's buffer that we need to repurpose for storing
// ciphertext. The end of the buffer will be used for such purposes.
const ciphertext_buf_len = (free_size / 2) -| in_stack_buffer.len;
// The amount of the user's buffer that will be used to give cleartext. The
// beginning of the buffer will be used for such purposes.
const cleartext_buf_len = free_size - ciphertext_buf_len;
// Recoup `partially_read_buffer space`. This is necessary because it is assumed
// below that `frag0` is big enough to hold at least one record.
limitedOverlapCopy(c.partially_read_buffer[0..c.partial_ciphertext_end], c.partial_ciphertext_idx);
c.partial_ciphertext_end -= c.partial_ciphertext_idx;
c.partial_ciphertext_idx = 0;
c.partial_cleartext_idx = 0;
const first_iov = c.partially_read_buffer[c.partial_ciphertext_end..];
var ask_iovecs_buf: [2]std.os.iovec = .{
.{
.iov_base = first_iov.ptr,
.iov_len = first_iov.len,
},
.{
.iov_base = &in_stack_buffer,
.iov_len = in_stack_buffer.len,
},
};
// Cleartext capacity of output buffer, in records. Minimum one full record.
const buf_cap = @max(cleartext_buf_len / max_ciphertext_len, 1);
const wanted_read_len = buf_cap * (max_ciphertext_len + tls.record_header_len);
const ask_len = @max(wanted_read_len, cleartext_stack_buffer.len);
const ask_iovecs = limitVecs(&ask_iovecs_buf, ask_len);
const actual_read_len = try stream.readv(ask_iovecs);
if (actual_read_len == 0) {
// This is either a truncation attack, a bug in the server, or an
// intentional omission of the close_notify message due to truncation
// detection handled above the TLS layer.
if (c.allow_truncation_attacks) {
c.received_close_notify = true;
} else {
return error.TlsConnectionTruncated;
}
}
// There might be more bytes inside `in_stack_buffer` that need to be processed,
// but at least frag0 will have one complete ciphertext record.
const frag0_end = @min(c.partially_read_buffer.len, c.partial_ciphertext_end + actual_read_len);
const frag0 = c.partially_read_buffer[c.partial_ciphertext_idx..frag0_end];
var frag1 = in_stack_buffer[0..actual_read_len -| first_iov.len];
// We need to decipher frag0 and frag1 but there may be a ciphertext record
// straddling the boundary. We can handle this with two memcpy() calls to
// assemble the straddling record in between handling the two sides.
var frag = frag0;
var in: usize = 0;
while (true) {
if (in == frag.len) {
// Perfect split.
if (frag.ptr == frag1.ptr) {
c.partial_ciphertext_end = c.partial_ciphertext_idx;
return vp.total;
}
frag = frag1;
in = 0;
continue;
}
if (in + tls.record_header_len > frag.len) {
if (frag.ptr == frag1.ptr)
return finishRead(c, frag, in, vp.total);
const first = frag[in..];
if (frag1.len < tls.record_header_len)
return finishRead2(c, first, frag1, vp.total);
// A record straddles the two fragments. Copy into the now-empty first fragment.
const record_len_byte_0: u16 = straddleByte(frag, frag1, in + 3);
const record_len_byte_1: u16 = straddleByte(frag, frag1, in + 4);
const record_len = (record_len_byte_0 << 8) | record_len_byte_1;
if (record_len > max_ciphertext_len) return error.TlsRecordOverflow;
const full_record_len = record_len + tls.record_header_len;
const second_len = full_record_len - first.len;
if (frag1.len < second_len)
return finishRead2(c, first, frag1, vp.total);
limitedOverlapCopy(frag, in);
@memcpy(frag[first.len..][0..second_len], frag1[0..second_len]);
frag = frag[0..full_record_len];
frag1 = frag1[second_len..];
in = 0;
continue;
}
const ct: tls.ContentType = @enumFromInt(frag[in]);
in += 1;
const legacy_version = mem.readInt(u16, frag[in..][0..2], .big);
in += 2;
_ = legacy_version;
const record_len = mem.readInt(u16, frag[in..][0..2], .big);
if (record_len > max_ciphertext_len) return error.TlsRecordOverflow;
in += 2;
const end = in + record_len;
if (end > frag.len) {
// We need the record header on the next iteration of the loop.
in -= tls.record_header_len;
if (frag.ptr == frag1.ptr)
return finishRead(c, frag, in, vp.total);
// A record straddles the two fragments. Copy into the now-empty first fragment.
const first = frag[in..];
const full_record_len = record_len + tls.record_header_len;
const second_len = full_record_len - first.len;
if (frag1.len < second_len)
return finishRead2(c, first, frag1, vp.total);
limitedOverlapCopy(frag, in);
@memcpy(frag[first.len..][0..second_len], frag1[0..second_len]);
frag = frag[0..full_record_len];
frag1 = frag1[second_len..];
in = 0;
continue;
}
switch (ct) {
.alert => {
if (in + 2 > frag.len) return error.TlsDecodeError;
const level: tls.AlertLevel = @enumFromInt(frag[in]);
const desc: tls.AlertDescription = @enumFromInt(frag[in + 1]);
_ = level;
try desc.toError();
// TODO: handle server-side closures
return error.TlsUnexpectedMessage;
},
.application_data => {
const cleartext = switch (c.application_cipher) {
inline else => |*p| c: {
const P = @TypeOf(p.*);
const ad = frag[in - 5 ..][0..5];
const ciphertext_len = record_len - P.AEAD.tag_length;
const ciphertext = frag[in..][0..ciphertext_len];
in += ciphertext_len;
const auth_tag = frag[in..][0..P.AEAD.tag_length].*;
const nonce = if (builtin.zig_backend == .stage2_x86_64 and
P.AEAD.nonce_length > comptime std.simd.suggestVectorLength(u8) orelse 1)
nonce: {
var nonce = p.server_iv;
const operand = std.mem.readInt(u64, nonce[nonce.len - 8 ..], .big);
std.mem.writeInt(u64, nonce[nonce.len - 8 ..], operand ^ c.read_seq, .big);
break :nonce nonce;
} else nonce: {
const V = @Vector(P.AEAD.nonce_length, u8);
const pad = [1]u8{0} ** (P.AEAD.nonce_length - 8);
const operand: V = pad ++ @as([8]u8, @bitCast(big(c.read_seq)));
break :nonce @as(V, p.server_iv) ^ operand;
};
const out_buf = vp.peek();
const cleartext_buf = if (ciphertext.len <= out_buf.len)
out_buf
else
&cleartext_stack_buffer;
const cleartext = cleartext_buf[0..ciphertext.len];
P.AEAD.decrypt(cleartext, ciphertext, auth_tag, ad, nonce, p.server_key) catch
return error.TlsBadRecordMac;
break :c cleartext;
},
};
c.read_seq = try std.math.add(u64, c.read_seq, 1);
const inner_ct: tls.ContentType = @enumFromInt(cleartext[cleartext.len - 1]);
switch (inner_ct) {
.alert => {
const level: tls.AlertLevel = @enumFromInt(cleartext[0]);
const desc: tls.AlertDescription = @enumFromInt(cleartext[1]);
if (desc == .close_notify) {
c.received_close_notify = true;
c.partial_ciphertext_end = c.partial_ciphertext_idx;
return vp.total;
}
_ = level;
try desc.toError();
// TODO: handle server-side closures
return error.TlsUnexpectedMessage;
},
.handshake => {
var ct_i: usize = 0;
while (true) {
const handshake_type: tls.HandshakeType = @enumFromInt(cleartext[ct_i]);
ct_i += 1;
const handshake_len = mem.readInt(u24, cleartext[ct_i..][0..3], .big);
ct_i += 3;
const next_handshake_i = ct_i + handshake_len;
if (next_handshake_i > cleartext.len - 1)
return error.TlsBadLength;
const handshake = cleartext[ct_i..next_handshake_i];
switch (handshake_type) {
.new_session_ticket => {
// This client implementation ignores new session tickets.
},
.key_update => {
switch (c.application_cipher) {
inline else => |*p| {
const P = @TypeOf(p.*);
const server_secret = hkdfExpandLabel(P.Hkdf, p.server_secret, "traffic upd", "", P.Hash.digest_length);
p.server_secret = server_secret;
p.server_key = hkdfExpandLabel(P.Hkdf, server_secret, "key", "", P.AEAD.key_length);
p.server_iv = hkdfExpandLabel(P.Hkdf, server_secret, "iv", "", P.AEAD.nonce_length);
},
}
c.read_seq = 0;
switch (@as(tls.KeyUpdateRequest, @enumFromInt(handshake[0]))) {
.update_requested => {
switch (c.application_cipher) {
inline else => |*p| {
const P = @TypeOf(p.*);
const client_secret = hkdfExpandLabel(P.Hkdf, p.client_secret, "traffic upd", "", P.Hash.digest_length);
p.client_secret = client_secret;
p.client_key = hkdfExpandLabel(P.Hkdf, client_secret, "key", "", P.AEAD.key_length);
p.client_iv = hkdfExpandLabel(P.Hkdf, client_secret, "iv", "", P.AEAD.nonce_length);
},
}
c.write_seq = 0;
},
.update_not_requested => {},
_ => return error.TlsIllegalParameter,
}
},
else => {
return error.TlsUnexpectedMessage;
},
}
ct_i = next_handshake_i;
if (ct_i >= cleartext.len - 1) break;
}
},
.application_data => {
// Determine whether the output buffer or a stack
// buffer was used for storing the cleartext.
if (cleartext.ptr == &cleartext_stack_buffer) {
// Stack buffer was used, so we must copy to the output buffer.
const msg = cleartext[0 .. cleartext.len - 1];
if (c.partial_ciphertext_idx > c.partial_cleartext_idx) {
// We have already run out of room in iovecs. Continue
// appending to `partially_read_buffer`.
@memcpy(
c.partially_read_buffer[c.partial_ciphertext_idx..][0..msg.len],
msg,
);
c.partial_ciphertext_idx = @intCast(c.partial_ciphertext_idx + msg.len);
} else {
const amt = vp.put(msg);
if (amt < msg.len) {
const rest = msg[amt..];
c.partial_cleartext_idx = 0;
c.partial_ciphertext_idx = @intCast(rest.len);
@memcpy(c.partially_read_buffer[0..rest.len], rest);
}
}
} else {
// Output buffer was used directly which means no
// memory copying needs to occur, and we can move
// on to the next ciphertext record.
vp.next(cleartext.len - 1);
}
},
else => {
return error.TlsUnexpectedMessage;
},
}
},
else => {
return error.TlsUnexpectedMessage;
},
}
in = end;
}
}
fn finishRead(c: *Client, frag: []const u8, in: usize, out: usize) usize {
const saved_buf = frag[in..];
if (c.partial_ciphertext_idx > c.partial_cleartext_idx) {
// There is cleartext at the beginning already which we need to preserve.
c.partial_ciphertext_end = @intCast(c.partial_ciphertext_idx + saved_buf.len);
@memcpy(c.partially_read_buffer[c.partial_ciphertext_idx..][0..saved_buf.len], saved_buf);
} else {
c.partial_cleartext_idx = 0;
c.partial_ciphertext_idx = 0;
c.partial_ciphertext_end = @intCast(saved_buf.len);
@memcpy(c.partially_read_buffer[0..saved_buf.len], saved_buf);
}
return out;
}
/// Note that `first` usually overlaps with `c.partially_read_buffer`.
fn finishRead2(c: *Client, first: []const u8, frag1: []const u8, out: usize) usize {
if (c.partial_ciphertext_idx > c.partial_cleartext_idx) {
// There is cleartext at the beginning already which we need to preserve.
c.partial_ciphertext_end = @intCast(c.partial_ciphertext_idx + first.len + frag1.len);
// TODO: eliminate this call to copyForwards
std.mem.copyForwards(u8, c.partially_read_buffer[c.partial_ciphertext_idx..][0..first.len], first);
@memcpy(c.partially_read_buffer[c.partial_ciphertext_idx + first.len ..][0..frag1.len], frag1);
} else {
c.partial_cleartext_idx = 0;
c.partial_ciphertext_idx = 0;
c.partial_ciphertext_end = @intCast(first.len + frag1.len);
// TODO: eliminate this call to copyForwards
std.mem.copyForwards(u8, c.partially_read_buffer[0..first.len], first);
@memcpy(c.partially_read_buffer[first.len..][0..frag1.len], frag1);
}
return out;
}
fn limitedOverlapCopy(frag: []u8, in: usize) void {
const first = frag[in..];
if (first.len <= in) {
// A single, non-overlapping memcpy suffices.
@memcpy(frag[0..first.len], first);
} else {
// One memcpy call would overlap, so just do this instead.
std.mem.copyForwards(u8, frag, first);
}
}
fn straddleByte(s1: []const u8, s2: []const u8, index: usize) u8 {
if (index < s1.len) {
return s1[index];
} else {
return s2[index - s1.len];
}
}
const builtin = @import("builtin");
const native_endian = builtin.cpu.arch.endian();
inline fn big(x: anytype) @TypeOf(x) {
return switch (native_endian) {
.big => x,
.little => @byteSwap(x),
};
}
fn SchemeEcdsa(comptime scheme: tls.SignatureScheme) type {
return switch (scheme) {
.ecdsa_secp256r1_sha256 => crypto.sign.ecdsa.EcdsaP256Sha256,
.ecdsa_secp384r1_sha384 => crypto.sign.ecdsa.EcdsaP384Sha384,
else => @compileError("bad scheme"),
};
}
fn SchemeHash(comptime scheme: tls.SignatureScheme) type {
return switch (scheme) {
.rsa_pss_rsae_sha256 => crypto.hash.sha2.Sha256,
.rsa_pss_rsae_sha384 => crypto.hash.sha2.Sha384,
.rsa_pss_rsae_sha512 => crypto.hash.sha2.Sha512,
else => @compileError("bad scheme"),
};
}
fn SchemeEddsa(comptime scheme: tls.SignatureScheme) type {
return switch (scheme) {
.ed25519 => crypto.sign.Ed25519,
else => @compileError("bad scheme"),
};
}
/// Abstraction for sending multiple byte buffers to a slice of iovecs.
const VecPut = struct {
iovecs: []const std.os.iovec,
idx: usize = 0,
off: usize = 0,
total: usize = 0,
/// Returns the amount actually put which is always equal to bytes.len
/// unless the vectors ran out of space.
fn put(vp: *VecPut, bytes: []const u8) usize {
if (vp.idx >= vp.iovecs.len) return 0;
var bytes_i: usize = 0;
while (true) {
const v = vp.iovecs[vp.idx];
const dest = v.iov_base[vp.off..v.iov_len];
const src = bytes[bytes_i..][0..@min(dest.len, bytes.len - bytes_i)];
@memcpy(dest[0..src.len], src);
bytes_i += src.len;
vp.off += src.len;
if (vp.off >= v.iov_len) {
vp.off = 0;
vp.idx += 1;
if (vp.idx >= vp.iovecs.len) {
vp.total += bytes_i;
return bytes_i;
}
}
if (bytes_i >= bytes.len) {
vp.total += bytes_i;
return bytes_i;
}
}
}
/// Returns the next buffer that consecutive bytes can go into.
fn peek(vp: VecPut) []u8 {
if (vp.idx >= vp.iovecs.len) return &.{};
const v = vp.iovecs[vp.idx];
return v.iov_base[vp.off..v.iov_len];
}
// After writing to the result of peek(), one can call next() to
// advance the cursor.
fn next(vp: *VecPut, len: usize) void {
vp.total += len;
vp.off += len;
if (vp.off >= vp.iovecs[vp.idx].iov_len) {
vp.off = 0;
vp.idx += 1;
}
}
fn freeSize(vp: VecPut) usize {
if (vp.idx >= vp.iovecs.len) return 0;
var total: usize = 0;
total += vp.iovecs[vp.idx].iov_len - vp.off;
if (vp.idx + 1 >= vp.iovecs.len) return total;
for (vp.iovecs[vp.idx + 1 ..]) |v| total += v.iov_len;
return total;
}
};
/// Limit iovecs to a specific byte size.
fn limitVecs(iovecs: []std.os.iovec, len: usize) []std.os.iovec {
var bytes_left: usize = len;
for (iovecs, 0..) |*iovec, vec_i| {
if (bytes_left <= iovec.iov_len) {
iovec.iov_len = bytes_left;
return iovecs[0 .. vec_i + 1];
}
bytes_left -= iovec.iov_len;
}
return iovecs;
}
/// The priority order here is chosen based on what crypto algorithms Zig has
/// available in the standard library as well as what is faster. Following are
/// a few data points on the relative performance of these algorithms.
///
/// Measurement taken with 0.11.0-dev.810+c2f5848fe
/// on x86_64-linux Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz:
/// zig run .lib/std/crypto/benchmark.zig -OReleaseFast
/// aegis-128l: 15382 MiB/s
/// aegis-256: 9553 MiB/s
/// aes128-gcm: 3721 MiB/s
/// aes256-gcm: 3010 MiB/s
/// chacha20Poly1305: 597 MiB/s
///
/// Measurement taken with 0.11.0-dev.810+c2f5848fe
/// on x86_64-linux Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz:
/// zig run .lib/std/crypto/benchmark.zig -OReleaseFast -mcpu=baseline
/// aegis-128l: 629 MiB/s
/// chacha20Poly1305: 529 MiB/s
/// aegis-256: 461 MiB/s
/// aes128-gcm: 138 MiB/s
/// aes256-gcm: 120 MiB/s
const cipher_suites = if (crypto.core.aes.has_hardware_support)
enum_array(tls.CipherSuite, &.{
.AEGIS_128L_SHA256,
.AEGIS_256_SHA512,
.AES_128_GCM_SHA256,
.AES_256_GCM_SHA384,
.CHACHA20_POLY1305_SHA256,
})
else
enum_array(tls.CipherSuite, &.{
.CHACHA20_POLY1305_SHA256,
.AEGIS_128L_SHA256,
.AEGIS_256_SHA512,
.AES_128_GCM_SHA256,
.AES_256_GCM_SHA384,
});
test {
_ = StreamInterface;
}