ic-kdf — key derivation

• [hkdf] — RFC 5869 extract-and-expand (SP 800-56C two-step).
• [pbkdf2()] — SP 800-132 password-based derivation.
• [kbkdf] — SP 800-108 counter-mode KDF over HMAC.
• [argon2()] — RFC 9106 memory-hard password hashing.

The HMAC-based functions are generic over the instantiation, so the same code path serves SHA-256, SHA-384, SHA-512, and the SHA-3 family.

Choosing between the two password KDFs

[pbkdf2()] is the only approved option and is not memory-hard, so a GPU attacks it far faster than a CPU defends it. [argon2()] is memory-hard and is what RFC 9106 recommends, but is not FIPS-approved. If you have a FIPS obligation the choice is made for you; otherwise reach for Argon2id.

use ic_kdf::hkdf::Hkdf;
use ic_core::traits::Kdf;
use ic_mac::HmacSha256;

let mut key = [0u8; 32];
Hkdf::<HmacSha256>::derive(b"input keying material", b"salt", b"app v1", &mut key)?;
# Ok::<(), ic_core::Error>(())