Function derive_key 

pub fn derive_key(
    out: &mut [u8],
    password: &[u8],
    salt: &[u8],
    secret: &[u8],
    ad: &[u8],
    params: &Params,
) -> Result<(), Argon2Error>

Derive a key using Argon2id (RFC 9106).

This is the main entry point for Argon2id key derivation. The derived key is written into out; its length determines the Argon2 output length and must be at least 4 bytes.

Arguments

• out - Output buffer for the derived key. Its length is the tag length.
• password - The password to hash
• salt - Salt (recommended 16 bytes)
• secret - Optional secret key (can be empty)
• ad - Optional associated data (can be empty)
• params - Argon2id parameters

Errors

Returns Argon2Error::InvalidParams if out is shorter than 4 bytes or if params is invalid.

Example

use crypto::argon2::{derive_key, Params};

let mut tag = [0u8; 32];
derive_key(
    &mut tag,
    b"correct horse battery staple",
    b"randomsalt123456",
    &[],  // no secret
    &[],  // no associated data
    &Params { iterations: 3, memory: 65536, parallelism: 4 },
).unwrap();
assert_eq!(tag.len(), 32);