//! `crypto_stream_xsalsa20`, 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_xsalsa20, crypto_stream_xsalsa20_KEYBYTES, crypto_stream_xsalsa20_NONCEBYTES,
    crypto_stream_xsalsa20_xor,
};

stream_module!(
    crypto_stream_xsalsa20,
    crypto_stream_xsalsa20_xor,
    crypto_stream_xsalsa20_KEYBYTES,
    crypto_stream_xsalsa20_NONCEBYTES
);

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

    #[test]
    fn test_vector_1() {
        // corresponding to tests/stream.c and tests/stream5.cpp from NaCl
        use crate::crypto::hash::sha256::{hash, Digest};
        let firstkey = Key([
            0x1b, 0x27, 0x55, 0x64, 0x73, 0xe9, 0x85, 0xd4, 0x62, 0xcd, 0x51, 0x19, 0x7a, 0x9a,
            0x46, 0xc7, 0x60, 0x09, 0x54, 0x9e, 0xac, 0x64, 0x74, 0xf2, 0x06, 0xc4, 0xee, 0x08,
            0x44, 0xf6, 0x83, 0x89,
        ]);
        let nonce = Nonce([
            0x69, 0x69, 0x6e, 0xe9, 0x55, 0xb6, 0x2b, 0x73, 0xcd, 0x62, 0xbd, 0xa8, 0x75, 0xfc,
            0x73, 0xd6, 0x82, 0x19, 0xe0, 0x03, 0x6b, 0x7a, 0x0b, 0x37,
        ]);
        let output = stream(4194304, &nonce, &firstkey);
        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);
    }

    #[test]
    fn test_vector_2() {
        // corresponding to tests/stream3.c and tests/stream7.cpp from NaCl
        let firstkey = Key([
            0x1b, 0x27, 0x55, 0x64, 0x73, 0xe9, 0x85, 0xd4, 0x62, 0xcd, 0x51, 0x19, 0x7a, 0x9a,
            0x46, 0xc7, 0x60, 0x09, 0x54, 0x9e, 0xac, 0x64, 0x74, 0xf2, 0x06, 0xc4, 0xee, 0x08,
            0x44, 0xf6, 0x83, 0x89,
        ]);
        let nonce = Nonce([
            0x69, 0x69, 0x6e, 0xe9, 0x55, 0xb6, 0x2b, 0x73, 0xcd, 0x62, 0xbd, 0xa8, 0x75, 0xfc,
            0x73, 0xd6, 0x82, 0x19, 0xe0, 0x03, 0x6b, 0x7a, 0x0b, 0x37,
        ]);
        let rs = stream(32, &nonce, &firstkey);
        let rs_expected = vec![
            0xee, 0xa6, 0xa7, 0x25, 0x1c, 0x1e, 0x72, 0x91, 0x6d, 0x11, 0xc2, 0xcb, 0x21, 0x4d,
            0x3c, 0x25, 0x25, 0x39, 0x12, 0x1d, 0x8e, 0x23, 0x4e, 0x65, 0x2d, 0x65, 0x1f, 0xa4,
            0xc8, 0xcf, 0xf8, 0x80,
        ];
        assert!(rs == rs_expected);
    }

    #[test]
    fn test_vector_3() {
        // corresponding to tests/stream4.c and tests/stream8.cpp from NaCl
        let firstkey = Key([
            0x1b, 0x27, 0x55, 0x64, 0x73, 0xe9, 0x85, 0xd4, 0x62, 0xcd, 0x51, 0x19, 0x7a, 0x9a,
            0x46, 0xc7, 0x60, 0x09, 0x54, 0x9e, 0xac, 0x64, 0x74, 0xf2, 0x06, 0xc4, 0xee, 0x08,
            0x44, 0xf6, 0x83, 0x89,
        ]);
        let nonce = Nonce([
            0x69, 0x69, 0x6e, 0xe9, 0x55, 0xb6, 0x2b, 0x73, 0xcd, 0x62, 0xbd, 0xa8, 0x75, 0xfc,
            0x73, 0xd6, 0x82, 0x19, 0xe0, 0x03, 0x6b, 0x7a, 0x0b, 0x37,
        ]);
        let m = &[
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0xbe, 0x07, 0x5f, 0xc5, 0x3c, 0x81, 0xf2, 0xd5, 0xcf, 0x14, 0x13, 0x16, 0xeb,
            0xeb, 0x0c, 0x7b, 0x52, 0x28, 0xc5, 0x2a, 0x4c, 0x62, 0xcb, 0xd4, 0x4b, 0x66, 0x84,
            0x9b, 0x64, 0x24, 0x4f, 0xfc, 0xe5, 0xec, 0xba, 0xaf, 0x33, 0xbd, 0x75, 0x1a, 0x1a,
            0xc7, 0x28, 0xd4, 0x5e, 0x6c, 0x61, 0x29, 0x6c, 0xdc, 0x3c, 0x01, 0x23, 0x35, 0x61,
            0xf4, 0x1d, 0xb6, 0x6c, 0xce, 0x31, 0x4a, 0xdb, 0x31, 0x0e, 0x3b, 0xe8, 0x25, 0x0c,
            0x46, 0xf0, 0x6d, 0xce, 0xea, 0x3a, 0x7f, 0xa1, 0x34, 0x80, 0x57, 0xe2, 0xf6, 0x55,
            0x6a, 0xd6, 0xb1, 0x31, 0x8a, 0x02, 0x4a, 0x83, 0x8f, 0x21, 0xaf, 0x1f, 0xde, 0x04,
            0x89, 0x77, 0xeb, 0x48, 0xf5, 0x9f, 0xfd, 0x49, 0x24, 0xca, 0x1c, 0x60, 0x90, 0x2e,
            0x52, 0xf0, 0xa0, 0x89, 0xbc, 0x76, 0x89, 0x70, 0x40, 0xe0, 0x82, 0xf9, 0x37, 0x76,
            0x38, 0x48, 0x64, 0x5e, 0x07, 0x05,
        ];

        let c = stream_xor(m, &nonce, &firstkey);
        let c_expected = [
            0x8e, 0x99, 0x3b, 0x9f, 0x48, 0x68, 0x12, 0x73, 0xc2, 0x96, 0x50, 0xba, 0x32, 0xfc,
            0x76, 0xce, 0x48, 0x33, 0x2e, 0xa7, 0x16, 0x4d, 0x96, 0xa4, 0x47, 0x6f, 0xb8, 0xc5,
            0x31, 0xa1, 0x18, 0x6a, 0xc0, 0xdf, 0xc1, 0x7c, 0x98, 0xdc, 0xe8, 0x7b, 0x4d, 0xa7,
            0xf0, 0x11, 0xec, 0x48, 0xc9, 0x72, 0x71, 0xd2, 0xc2, 0x0f, 0x9b, 0x92, 0x8f, 0xe2,
            0x27, 0x0d, 0x6f, 0xb8, 0x63, 0xd5, 0x17, 0x38, 0xb4, 0x8e, 0xee, 0xe3, 0x14, 0xa7,
            0xcc, 0x8a, 0xb9, 0x32, 0x16, 0x45, 0x48, 0xe5, 0x26, 0xae, 0x90, 0x22, 0x43, 0x68,
            0x51, 0x7a, 0xcf, 0xea, 0xbd, 0x6b, 0xb3, 0x73, 0x2b, 0xc0, 0xe9, 0xda, 0x99, 0x83,
            0x2b, 0x61, 0xca, 0x01, 0xb6, 0xde, 0x56, 0x24, 0x4a, 0x9e, 0x88, 0xd5, 0xf9, 0xb3,
            0x79, 0x73, 0xf6, 0x22, 0xa4, 0x3d, 0x14, 0xa6, 0x59, 0x9b, 0x1f, 0x65, 0x4c, 0xb4,
            0x5a, 0x74, 0xe3, 0x55, 0xa5,
        ];
        assert!(&c[32..] == &c_expected[..]);
    }
}
