HkdfSha256 class

HKDF-SHA256 (RFC 5869): extract-then-expand key derivation.

Deterministic — the same (ikm, salt, info, length) always yields the same output, so two parties holding the same input key material derive identical sub-keys without communicating (e.g. a shared group secret's per-label export, or NoPorts session keys).

Constructors

HkdfSha256()

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

deriveKey(Uint8List ikm, {Uint8List? salt, Uint8List? info, required int length}) → Uint8List

Derives length bytes from input-key-material ikm, optionally keyed by salt (defaults to all-zeros, per RFC 5869) and bound to a context info (defaults to empty).

expand(Uint8List prk, {Uint8List? info, required int length}) → Uint8List

RFC 5869 Expand on its own: T(i) = HMAC-SHA256(prk, T(i-1) || info || i), truncated to length.

extract(Uint8List ikm, {Uint8List? salt}) → Uint8List

RFC 5869 Extract on its own: PRK = HMAC-SHA256(salt, ikm).

Constants

hashLen → const int

SHA-256 output size in bytes; the per-block expand step yields this much.