Types
Tls13Suite = enum tlsAes128GcmSha256, ## `TLS_AES_128_GCM_SHA256` (HKDF-SHA-256). tlsAes256GcmSha384, ## `TLS_AES_256_GCM_SHA384` (HKDF-SHA-384). tlsChacha20Poly1305Sha256 ## `TLS_CHACHA20_POLY1305_SHA256` (HKDF-SHA-256).
Procs
proc hkdfExpandLabel(secret: openArray[byte]; label: string; context: openArray[byte]; outLen: Natural; hashLen: Natural): seq[ byte] {....raises: [ValueError], tags: [], forbids: [].}
- HKDF-Expand-Label(Secret, Label, Context, Length) with the "tls13 " prefix. hashLen selects SHA-256 (32) or SHA-384 (48).
proc nextTrafficSecret(secret: openArray[byte]; hashLen: Natural): seq[byte] {. ...raises: [ValueError], tags: [], forbids: [].}
- Advance a traffic secret on KeyUpdate (RFC 8446 §7.2).
proc parseTls13Suite(name: string): Tls13Suite {....raises: [ValueError], tags: [], forbids: [].}
- Parse an OpenSSL-style suite name (TLS_AES_128_GCM_SHA256, …).
proc suiteCipher(s: Tls13Suite): CipherSuite {....raises: [], tags: [], forbids: [].}
proc suiteHashLen(s: Tls13Suite): Natural {....raises: [], tags: [], forbids: [].}
proc toKeyMaterial(suite: Tls13Suite; secret: openArray[byte]; recSeq: array[8, byte] = [0'u8, 0, 0, 0, 0, 0, 0, 0]): KeyMaterial {. ...raises: [ValueError, KtlsError], tags: [], forbids: [].}
- Expand a TLS 1.3 traffic secret into kernel KeyMaterial, splitting the 12-byte IV into the kernel's salt + iv layout (ChaCha20-Poly1305 keeps the full 12-byte IV, empty salt).
proc trafficIv(secret: openArray[byte]; hashLen: Natural): array[12, byte] {. ...raises: [ValueError], tags: [], forbids: [].}
- Derive the 12-byte iv for a traffic secret.
proc trafficKey(secret: openArray[byte]; hashLen: Natural; keyLen: Natural): seq[ byte] {....raises: [ValueError], tags: [], forbids: [].}
- Derive the key for a traffic secret.