Argon2 Bindings

Bindings to the Argon2 C library for Rust. The C implementation can be found at https://github.com/P-H-C/phc-winner-argon2

Example Usage

```rust fn main() { const HASHLEN: usize = 32; const SALTLEN: usize = 16; const PWD: &[u8] = b"password"; const PWDLEN: usize = 8;

// so these don't get out of sync
assert_eq!(PWD.len(), PWDLEN);

let t_cost      = 2;            // 1-pass computation
let m_cost      = 1 << 16;      // 64 mebibytes memory usage
let parallelism = 1;            // number of threads and lanes

let mut hash1   = [0u8; HASHLEN];
let mut hash2   = [0u8; HASHLEN];
let mut salt    = [0u8; SALTLEN];
let mut pwd     = [0u8; PWDLEN];

// Copy the password string into the array.
pwd.copy_from_slice(PWD);

// High-level API
argon2::i_hash_raw(t_cost, m_cost, parallelism, Some(&mut pwd), Some(&mut salt), &mut hash1).expect("Error hashing using high-level API.");

// Low-level API
let mut context = argon2::Context {
    out:        &mut hash2,
    pwd:        Some(&mut pwd),
    salt:       Some(&mut salt),
    secret:     None,
    ad:         None,
    t_cost:     t_cost,
    m_cost:     m_cost,
    lanes:      parallelism,
    threads:    parallelism,
    version:    argon2::Version::Version13,
    flags:      argon2::Flags::DEFAULT,
};
argon2::i_ctx(&mut context).expect("Error hashing using low-level API.");

assert_eq!(&hash1[0..], &hash2[0..], "Hashes do not match.");

println!("Hashes match.");

} ```