Haskell STUN (Session Traversal Utilities for NAT) implementation

Protocol specifications:

STUN:

• RFC5389: Session Traversal Utilities for NAT (STUN)
• RFC5780: NAT Behavior Discovery Using Session Traversal Utilities for NAT (STUN)

TURN:

• RFC5766: Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)
• RFC5928: Traversal Using Relays around NAT (TURN) Resolution Mechanism

Even moar:

• RFC7350: Datagram Transport Layer Security (DTLS) as Transport for Session Traversal Utilities for NAT (STUN)

Observed in the wild

Chrome's TURN

• C: Allocate Request [Requested-Transport]
• S: Allocate Error [Error-Code, Nonce, Realm, Software, Fingerprint]
• C: Allocate Request [Request-Transport, Username, Realm, Nonce, Message-Integrity]
• S: Allocate Success [XOR-Relayed-Address, XOR-Mapped-Address, Lifetime, Software, Message-Integrity, Fingerprint]
• C: Refresh Request [Lifetime, Username, Realm, Nonce, Message-Integrity]
• S: Refresh Success [Lifetime, Software, Message-Integrity, Fingerprint]

Firefox's TURN

• C: Allocate Request [Requested-Transport]
• S: Allocate Error [Error-Code, Nonce, Realm, Software, Fingerprint]
• C: Allocate Request [Request-Transport, Username, Realm, Nonce, Message-Integrity]
• S: Allocate Success [XOR-Relayed-Address, XOR-Mapped-Address, Lifetime, Software, Message-Integrity, Fingerprint]
• C: Refresh Request [Lifetime, Username, Realm, Nonce, Message-Integrity]
• S: Refresh Success [Lifetime, Software, Message-Integrity, Fingerprint]