Class DtlsSrtp

DTLS-SRTP over a datagram path, e.g. an ICE pair: a DTLS 1.2 handshake with BouncyCastle that checks the peer's certificate against its signalled fingerprint, and yields the SRTP sessions of both directions.

Inheritance
object
DtlsSrtp
Implements
Inherited Members
Namespace: Uniform.Matrix.WebRtc.Dtls
Assembly: Uniform.Matrix.WebRtc.dll
Syntax
public sealed class DtlsSrtp : IDisposable
Remarks

Feed the DTLS records received, those with first bytes 20 to 63 as RFC 7983 says, to Receive(byte[]). BouncyCastle's DTLS blocks, so the handshake runs on a thread of its own, and after it a thread keeps answering retransmissions and notices the peer closing.

Constructors

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DtlsSrtp(DtlsCertificate, bool, string, Action<byte[]>)

Prepare a handshake as client or server.

Declaration
public DtlsSrtp(DtlsCertificate certificate, bool isClient, string remoteFingerprint, Action<byte[]> send)
Parameters
Type Name Description
DtlsCertificate certificate

This side's certificate, whose fingerprint the local SDP carries.
bool isClient

Whether this side is the DTLS client: a=setup:active; the other is passive.
string remoteFingerprint

The peer's a=fingerprint, e.g. sha-256 AB:CD:….
Action<byte[]> send

Sends a datagram to the peer.

Methods

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Dispose()

Send close_notify, and stop.

Declaration
public void Dispose()
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HandshakeAsync(CancellationToken)

Run the handshake; return the SRTP session that protects what this side sends, and the one that unprotects what it receives.

Declaration
public Task<(SrtpSession Outbound, SrtpSession Inbound)> HandshakeAsync(CancellationToken cancellationToken = default)
Parameters
Type Name Description
CancellationToken cancellationToken
Returns
Type Description
Task<(SrtpSession Outbound, SrtpSession Inbound)>
Exceptions
Type Condition
TlsFatalAlert

On a failed handshake, e.g. a certificate that does not match the fingerprint.
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Receive(byte[])

Give a received DTLS record to the handshake.

Declaration
public void Receive(byte[] datagram)
Parameters
Type Name Description
byte[] datagram

Events

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Closed

Raised once when the peer closes DTLS, or it fails after the handshake.

Declaration
public event Action? Closed
Event Type
Type Description
Action

Implements