ddn.net.dtls.client13
DTLS 1.3 client handshake state machine (RFC 9147).
Drives the DTLS 1.3 client handshake as a resumable state machine. Adapts the TLS 1.3 handshake for datagram transports with:
- DTLS record framing (13-byte header)
- DTLS handshake framing (12-byte header with message_seq)
- Flight-based retransmission with exponential backoff
- DTLS 1.3 key schedule with "dtls13 " label prefix
- Encrypted handshake messages after ServerHello
Uses Tls13KeySchedule for cryptographic key derivation, DtlsTranscriptHash for transcript hashing, and Dtls13ClientKeySchedule for the "dtls13 " HKDF label prefix.
Types 2
DTLS 1.3 key schedule with "dtls13 " HKDF label prefix.
Overrides hkdfExpandLabel to use "dtls13 " instead of "tls13 " per RFC 9147 §5.
Fields
HKDF hkdf13_size_t hashLen13_Methods
void setCipherSuite(ushort cipherSuite)Reconfigures the hash algorithm based on the negotiated cipher suite.ubyte[] hkdfExpandLabel(const(ubyte)[] secret, string label,
const(ubyte)[] context, size_t length)HKDF-Expand-Label with "dtls13 " prefix for DTLS 1.3.Constructors
this()Constructs a DTLS 1.3 key schedule.classDtls13Client
DTLS 1.3 client handshake engine.
Drives the client side of a DTLS 1.3 handshake over a datagram transport. Uses flight-based retransmission with exponential backoff and supports the HelloRetryRequest cookie exchange.
Call handshake() repeatedly until it returns TlsProgress.DONE. Between calls, wait for socket readiness as indicated by the return value.
Fields
DtlsTransport transport_DtlsTimerSink timer_DatagramEndpoint serverAddr_Dtls13ClientPhase phase_ushort messageSeq_ushort epoch_ulong recordSeq_SecureRandom rng_DtlsFlight pendingFlight_int retryCount_ubyte[32] clientRandom_ubyte[32] serverRandom_ubyte[] sharedSecret_ubyte[] receivedCookie_X25519PrivateKey ecdhePrivate_NamedGroup selectedGroup_string serverName_DtlsVersion minVersion_DtlsVersion maxVersion_string[] alpnProtocols_SrtpProfile[] srtpProfiles_string negotiatedAlpn_CipherSuiteId negotiatedCipher_DtlsVersion negotiatedVersion_SrtpProfile negotiatedSrtpProfile_bool cidEnabled_ubyte localCidLength_DtlsConnectionId localCid_DtlsConnectionId peerCid_bool cidNegotiated_Dtls13ClientKeySchedule keySchedule_DtlsTranscriptHash transcript_TlsAead writeAead_TlsAead readAead_X509Certificate[] peerX509Certs_TlsCertificateChain peerCerts_TlsVerifyMode verifyMode_DtlsVerifyCallback verifyCallback_NativeTlsTrustStore trustStore_DtlsFragmentBuffer reassembly_ubyte[] pendingDatagram_DtlsSessionInfo resumptionSession_bool resumptionAttempt_bool resumptionAccepted_TlsAead earlyDataAead_bool earlyDataSent_ulong earlyDataRecordSeq_ubyte[] chBody_Methods
void setCidConfig(bool enabled, ubyte cidLength = DtlsCidConstants.DEFAULT_CID_LENGTH) @safe pure nothrow @nogcEnables Connection ID and sets the local CID length.DtlsConnectionId localCid() @property @safe pure nothrow @nogcReturns: The local Connection ID (set after negotiation).DtlsConnectionId peerCid() @property @safe pure nothrow @nogcReturns: The peer's Connection ID (set after ServerHello).void setResumptionSession(scope ref const DtlsSessionInfo session) @safe pure nothrowSets the session to resume.bool resumptionAccepted() @property const @safe pure nothrow @nogcReturns: true if resumption was attempted and accepted.bool resumptionAttempt() @property const @safe pure nothrow @nogcReturns: true if a resumption attempt will be made.bool earlyDataSent() @property const @safe pure nothrow @nogcReturns: true if early data has been sent.void initEarlyDataKeys()Initializes early traffic keys for 0-RTT.size_t writeEarlyData(const(ubyte)[] data)Writes early data (0-RTT) to the server.void setVerifyMode(TlsVerifyMode mode) @safe pure nothrow @nogcSets the certificate verification mode.void setVerifyCallback(DtlsVerifyCallback callback) @safe pure nothrowSets a custom certificate verification callback.void setTrustStore(NativeTlsTrustStore trustStore) @safe pure nothrowSets the trust store for certificate chain validation.ubyte[] buildClientHello(const(ubyte)[] cookie)Builds a DTLS 1.3 ClientHello handshake message.bool processServerHello(const(ubyte)[] datagram)Process a datagram containing a ServerHello.void parseServerHello(const(ubyte)[] body)Parse a ServerHello message body.void processServerHelloExtensions(const(ubyte)[] extData)Process extensions from a ServerHello.bool processHelloRetry(const(ubyte)[] datagram)Process a datagram that may contain a HelloRetryRequest.const(ubyte)[] extractHelloRetryCookie(const(ubyte)[] body)Extract the cookie from a HelloRetryRequest body.bool processEncryptedFlight(const(ubyte)[] datagram)Process an encrypted flight of handshake messages.ubyte[] decryptRecordPayload(const(ubyte)[] payload, DtlsRecordHeader header)Decrypt a record payload using the read AEAD.bool processHandshakePayload(const(ubyte)[] payload)Process a handshake payload from an encrypted record.bool dispatchHandshakeType(HandshakeType msgType, const(ubyte)[] body)Dispatch a complete handshake message to the appropriate handler.void processEncryptedExtensions(const(ubyte)[] body)Process an EncryptedExtensions message body.void processCertificate(const(ubyte)[] body)Process a Certificate message body.void processCertificateVerify(const(ubyte)[] body)Process a CertificateVerify message body.void performKeyExchange(NamedGroup group, const(ubyte)[] peerPubKey)Perform ECDHE key exchange.void deriveHandshakeKeys()Derives handshake traffic keys from the shared secret.void deriveAppKeys()Derives application traffic keys.size_t cipherKeyLength(CipherSuiteId cs) @safe pure nothrow @nogcReturns the AEAD key length for the given cipher suite.void processServerFinished(const(ubyte)[] body)Process a server Finished message body.ubyte[] buildClientFinished()Builds and encrypts a client Finished message.ubyte[] wrapHandshakeMessage(HandshakeType msgType, const(ubyte)[] body)Wraps a handshake message body in a DTLS handshake header.ubyte[] wrapInRecord(ContentType contentType, const(ubyte)[] payload)Wraps a handshake message in a DTLS record.ubyte[] buildDtlsRecord(ContentType contentType, const(ubyte)[] payload)Builds a complete DTLS record with 13-byte header.ubyte[] encryptRecord(ContentType contentType, const(ubyte)[] plaintext)Encrypts a record payload using the current write AEAD.const(ubyte)[] receiveDatagram()Receive a single datagram from the transport.void sendDatagram(const(ubyte)[] data)Send a datagram via the transport.void sendFlight(ubyte[][] records)Send a flight of records as one or more datagrams.void scheduleRetransmit()Schedule retransmission timer for the current flight.void retransmitFlight()Retransmit the pending flight.Dtls13ClientPhase phase() @property const @safe pure nothrow @nogcReturns: The current handshake phase.CipherSuiteId negotiatedCipher() @property const @safe pure nothrow @nogcReturns: The negotiated cipher suite.DtlsVersion negotiatedVersion() @property const @safe pure nothrow @nogcReturns: The negotiated DTLS version.Constructors
this(DtlsTransport transport, DtlsTimerSink timer,
DatagramEndpoint serverAddr, string serverName)Constructs a DTLS 1.3 client handshake engine.Variables 1
enumvar
DTLS_1_3_RECORD_VERSION = [0xFE, 0xFD]DTLS 1.3 record version used on the wire.
DTLS 1.3 uses the same record layer version as DTLS 1.2 (0xFEFD) for backwards compatibility per RFC 9147.