1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
//! `SipHash-2-4`
use ffi;
use libc::c_ulonglong;
use randombytes::randombytes_into;

/// Number of bytes in a `Digest`.
pub const DIGESTBYTES: usize = ffi::crypto_shorthash_siphash24_BYTES;

/// Number of bytes in a `Key`.
pub const KEYBYTES: usize = ffi::crypto_shorthash_siphash24_KEYBYTES;

new_type! {
    /// `Digest` structure
    public Digest(DIGESTBYTES);
}

new_type! {
    /// `Key`
    ///
    /// When a `Key` goes out of scope its contents will be zeroed out.
    secret Key(KEYBYTES);
}

/// `gen_key()` randomly generates a key for shorthash
///
/// THREAD SAFETY: `gen_key()` is thread-safe provided that you have
/// called `sodiumoxide::init()` once before using any other function
/// from sodiumoxide.
pub fn gen_key() -> Key {
    let mut k = [0; KEYBYTES];
    randombytes_into(&mut k);
    Key(k)
}

/// `shorthash` hashes a message `m` under a key `k`. It
/// returns a hash `h`.
pub fn shorthash(m: &[u8],
                 &Key(ref k): &Key) -> Digest {
    unsafe {
        let mut h = [0; DIGESTBYTES];
        ffi::crypto_shorthash_siphash24(&mut h, m.as_ptr(),
                                        m.len() as c_ulonglong,
                                        k);
        Digest(h)
    }
}

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

    #[test]
    fn test_vectors() {
        let maxlen = 64;
        let mut m = Vec::with_capacity(64);
        for i in 0usize..64 {
            m.push(i as u8);
        }
        let h_expecteds = [[0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72]
                          ,[0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74]
                          ,[0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d]
                          ,[0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85]
                          ,[0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf]
                          ,[0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18]
                          ,[0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb]
                          ,[0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab]
                          ,[0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93]
                          ,[0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e]
                          ,[0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a]
                          ,[0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4]
                          ,[0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75]
                          ,[0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14]
                          ,[0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7]
                          ,[0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1]
                          ,[0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f]
                          ,[0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69]
                          ,[0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b]
                          ,[0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb]
                          ,[0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe]
                          ,[0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0]
                          ,[0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93]
                          ,[0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8]
                          ,[0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8]
                          ,[0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc]
                          ,[0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17]
                          ,[0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f]
                          ,[0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde]
                          ,[0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6]
                          ,[0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad]
                          ,[0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32]
                          ,[0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71]
                          ,[0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7]
                          ,[0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12]
                          ,[0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15]
                          ,[0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31]
                          ,[0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02]
                          ,[0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca]
                          ,[0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a]
                          ,[0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e]
                          ,[0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad]
                          ,[0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18]
                          ,[0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4]
                          ,[0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9]
                          ,[0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9]
                          ,[0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb]
                          ,[0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0]
                          ,[0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6]
                          ,[0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7]
                          ,[0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee]
                          ,[0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1]
                          ,[0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a]
                          ,[0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81]
                          ,[0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f]
                          ,[0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24]
                          ,[0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7]
                          ,[0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea]
                          ,[0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60]
                          ,[0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66]
                          ,[0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c]
                          ,[0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f]
                          ,[0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5]
                          ,[0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95]];
        let k = Key([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]);
        for i in 0usize..maxlen {
            let Digest(h) = shorthash(&m[..i], &k);
            assert!(h == h_expecteds[i]);
        }
    }

    #[cfg(feature = "default")]
    #[test]
    fn test_serialisation() {
        use randombytes::randombytes;
        use test_utils::round_trip;
        for i in 0..64usize {
            let k = gen_key();
            let m = randombytes(i);
            let d = shorthash(&m[..], &k);
            round_trip(k);
            round_trip(d);
        }
    }
}

#[cfg(feature = "benchmarks")]
#[cfg(test)]
mod bench {
    extern crate test;
    use randombytes::randombytes;
    use super::*;

    const BENCH_SIZES: [usize; 14] = [0, 1, 2, 4, 8, 16, 32, 64,
                                      128, 256, 512, 1024, 2048, 4096];

    #[bench]
    fn bench_shorthash(b: &mut test::Bencher) {
        let k = gen_key();
        let ms: Vec<Vec<u8>> = BENCH_SIZES.iter().map(|s| {
            randombytes(*s)
        }).collect();
        b.iter(|| {
            for m in ms.iter() {
                shorthash(m, &k);
            }
        });
    }
}