//! `crypto_stream_salsa20` (Salsa20/20), a particular cipher specified in
//! [Cryptography in NaCl](http://nacl.cr.yp.to/valid.html), Section 7.  This
//! cipher is conjectured to meet the standard notion of unpredictability.
use ffi::{crypto_stream_salsa20,
          crypto_stream_salsa20_xor,
          crypto_stream_salsa20_KEYBYTES,
          crypto_stream_salsa20_NONCEBYTES};

stream_module!(crypto_stream_salsa20,
               crypto_stream_salsa20_xor,
               crypto_stream_salsa20_KEYBYTES,
               crypto_stream_salsa20_NONCEBYTES);

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn test_vector_1() {
        // corresponding to tests/stream2.c and tests/stream6.cpp from NaCl
        use crypto::hash::sha256::{hash, Digest};
        let secondkey = Key([0xdc,0x90,0x8d,0xda,0x0b,0x93,0x44,0xa9
                            ,0x53,0x62,0x9b,0x73,0x38,0x20,0x77,0x88
                            ,0x80,0xf3,0xce,0xb4,0x21,0xbb,0x61,0xb9
                            ,0x1c,0xbd,0x4c,0x3e,0x66,0x25,0x6c,0xe4]);
        let noncesuffix = Nonce([0x82,0x19,0xe0,0x03,0x6b,0x7a,0x0b,0x37]);
        let output = stream(4194304, &noncesuffix, &secondkey);
        let digest_expected = [0x66, 0x2b, 0x9d, 0x0e, 0x34, 0x63, 0x02, 0x91,
                               0x56, 0x06, 0x9b, 0x12, 0xf9, 0x18, 0x69, 0x1a,
                               0x98, 0xf7, 0xdf, 0xb2, 0xca, 0x03, 0x93, 0xc9,
                               0x6b, 0xbf, 0xc6, 0xb1, 0xfb, 0xd6, 0x30, 0xa2];
        let Digest(digest) = hash(&output);
        assert!(digest == digest_expected);
    }
}
