zig/lib/std/crypto/sha1.zig
Frank Denis 446597bd3c Remove the reset() function from hash functions
Justification:
- reset() is unnecessary; states that have to be reused can be copied
- reset() is error-prone. Copying a previous state prevents forgetting
  struct members.
- reset() forces implementation to store sensitive data (key, initial state)
  in memory even when they are not needed.
- reset() is confusing as it has a different meaning elsewhere in Zig.
2020-08-20 23:02:10 +02:00

306 lines
9.6 KiB
Zig

// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2020 Zig Contributors
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
// The MIT license requires this copyright notice to be included in all copies
// and substantial portions of the software.
const mem = @import("../mem.zig");
const math = @import("../math.zig");
const endian = @import("../endian.zig");
const debug = @import("../debug.zig");
const builtin = @import("builtin");
const RoundParam = struct {
a: usize,
b: usize,
c: usize,
d: usize,
e: usize,
i: u32,
};
fn Rp(a: usize, b: usize, c: usize, d: usize, e: usize, i: u32) RoundParam {
return RoundParam{
.a = a,
.b = b,
.c = c,
.d = d,
.e = e,
.i = i,
};
}
/// The SHA-1 function is now considered cryptographically broken.
/// Namely, it is feasible to find multiple inputs producing the same hash.
/// For a fast-performing, cryptographically secure hash function, see SHA512/256, BLAKE2 or BLAKE3.
pub const Sha1 = struct {
const Self = @This();
pub const block_length = 64;
pub const digest_length = 20;
s: [5]u32,
// Streaming Cache
buf: [64]u8 = undefined,
buf_len: u8 = 0,
total_len: u64 = 0,
pub fn init() Self {
return Self{
.s = [_]u32{
0x67452301,
0xEFCDAB89,
0x98BADCFE,
0x10325476,
0xC3D2E1F0,
},
};
}
pub fn hash(b: []const u8, out: []u8) void {
var d = Sha1.init();
d.update(b);
d.final(out);
}
pub fn update(d: *Self, b: []const u8) void {
var off: usize = 0;
// Partial buffer exists from previous update. Copy into buffer then hash.
if (d.buf_len != 0 and d.buf_len + b.len >= 64) {
off += 64 - d.buf_len;
mem.copy(u8, d.buf[d.buf_len..], b[0..off]);
d.round(d.buf[0..]);
d.buf_len = 0;
}
// Full middle blocks.
while (off + 64 <= b.len) : (off += 64) {
d.round(b[off .. off + 64]);
}
// Copy any remainder for next pass.
mem.copy(u8, d.buf[d.buf_len..], b[off..]);
d.buf_len += @intCast(u8, b[off..].len);
d.total_len += b.len;
}
pub fn final(d: *Self, out: []u8) void {
debug.assert(out.len >= 20);
// The buffer here will never be completely full.
mem.set(u8, d.buf[d.buf_len..], 0);
// Append padding bits.
d.buf[d.buf_len] = 0x80;
d.buf_len += 1;
// > 448 mod 512 so need to add an extra round to wrap around.
if (64 - d.buf_len < 8) {
d.round(d.buf[0..]);
mem.set(u8, d.buf[0..], 0);
}
// Append message length.
var i: usize = 1;
var len = d.total_len >> 5;
d.buf[63] = @intCast(u8, d.total_len & 0x1f) << 3;
while (i < 8) : (i += 1) {
d.buf[63 - i] = @intCast(u8, len & 0xff);
len >>= 8;
}
d.round(d.buf[0..]);
for (d.s) |s, j| {
mem.writeIntBig(u32, out[4 * j ..][0..4], s);
}
}
fn round(d: *Self, b: []const u8) void {
debug.assert(b.len == 64);
var s: [16]u32 = undefined;
var v: [5]u32 = [_]u32{
d.s[0],
d.s[1],
d.s[2],
d.s[3],
d.s[4],
};
const round0a = comptime [_]RoundParam{
Rp(0, 1, 2, 3, 4, 0),
Rp(4, 0, 1, 2, 3, 1),
Rp(3, 4, 0, 1, 2, 2),
Rp(2, 3, 4, 0, 1, 3),
Rp(1, 2, 3, 4, 0, 4),
Rp(0, 1, 2, 3, 4, 5),
Rp(4, 0, 1, 2, 3, 6),
Rp(3, 4, 0, 1, 2, 7),
Rp(2, 3, 4, 0, 1, 8),
Rp(1, 2, 3, 4, 0, 9),
Rp(0, 1, 2, 3, 4, 10),
Rp(4, 0, 1, 2, 3, 11),
Rp(3, 4, 0, 1, 2, 12),
Rp(2, 3, 4, 0, 1, 13),
Rp(1, 2, 3, 4, 0, 14),
Rp(0, 1, 2, 3, 4, 15),
};
inline for (round0a) |r| {
s[r.i] = (@as(u32, b[r.i * 4 + 0]) << 24) | (@as(u32, b[r.i * 4 + 1]) << 16) | (@as(u32, b[r.i * 4 + 2]) << 8) | (@as(u32, b[r.i * 4 + 3]) << 0);
v[r.e] = v[r.e] +% math.rotl(u32, v[r.a], @as(u32, 5)) +% 0x5A827999 +% s[r.i & 0xf] +% ((v[r.b] & v[r.c]) | (~v[r.b] & v[r.d]));
v[r.b] = math.rotl(u32, v[r.b], @as(u32, 30));
}
const round0b = comptime [_]RoundParam{
Rp(4, 0, 1, 2, 3, 16),
Rp(3, 4, 0, 1, 2, 17),
Rp(2, 3, 4, 0, 1, 18),
Rp(1, 2, 3, 4, 0, 19),
};
inline for (round0b) |r| {
const t = s[(r.i - 3) & 0xf] ^ s[(r.i - 8) & 0xf] ^ s[(r.i - 14) & 0xf] ^ s[(r.i - 16) & 0xf];
s[r.i & 0xf] = math.rotl(u32, t, @as(u32, 1));
v[r.e] = v[r.e] +% math.rotl(u32, v[r.a], @as(u32, 5)) +% 0x5A827999 +% s[r.i & 0xf] +% ((v[r.b] & v[r.c]) | (~v[r.b] & v[r.d]));
v[r.b] = math.rotl(u32, v[r.b], @as(u32, 30));
}
const round1 = comptime [_]RoundParam{
Rp(0, 1, 2, 3, 4, 20),
Rp(4, 0, 1, 2, 3, 21),
Rp(3, 4, 0, 1, 2, 22),
Rp(2, 3, 4, 0, 1, 23),
Rp(1, 2, 3, 4, 0, 24),
Rp(0, 1, 2, 3, 4, 25),
Rp(4, 0, 1, 2, 3, 26),
Rp(3, 4, 0, 1, 2, 27),
Rp(2, 3, 4, 0, 1, 28),
Rp(1, 2, 3, 4, 0, 29),
Rp(0, 1, 2, 3, 4, 30),
Rp(4, 0, 1, 2, 3, 31),
Rp(3, 4, 0, 1, 2, 32),
Rp(2, 3, 4, 0, 1, 33),
Rp(1, 2, 3, 4, 0, 34),
Rp(0, 1, 2, 3, 4, 35),
Rp(4, 0, 1, 2, 3, 36),
Rp(3, 4, 0, 1, 2, 37),
Rp(2, 3, 4, 0, 1, 38),
Rp(1, 2, 3, 4, 0, 39),
};
inline for (round1) |r| {
const t = s[(r.i - 3) & 0xf] ^ s[(r.i - 8) & 0xf] ^ s[(r.i - 14) & 0xf] ^ s[(r.i - 16) & 0xf];
s[r.i & 0xf] = math.rotl(u32, t, @as(u32, 1));
v[r.e] = v[r.e] +% math.rotl(u32, v[r.a], @as(u32, 5)) +% 0x6ED9EBA1 +% s[r.i & 0xf] +% (v[r.b] ^ v[r.c] ^ v[r.d]);
v[r.b] = math.rotl(u32, v[r.b], @as(u32, 30));
}
const round2 = comptime [_]RoundParam{
Rp(0, 1, 2, 3, 4, 40),
Rp(4, 0, 1, 2, 3, 41),
Rp(3, 4, 0, 1, 2, 42),
Rp(2, 3, 4, 0, 1, 43),
Rp(1, 2, 3, 4, 0, 44),
Rp(0, 1, 2, 3, 4, 45),
Rp(4, 0, 1, 2, 3, 46),
Rp(3, 4, 0, 1, 2, 47),
Rp(2, 3, 4, 0, 1, 48),
Rp(1, 2, 3, 4, 0, 49),
Rp(0, 1, 2, 3, 4, 50),
Rp(4, 0, 1, 2, 3, 51),
Rp(3, 4, 0, 1, 2, 52),
Rp(2, 3, 4, 0, 1, 53),
Rp(1, 2, 3, 4, 0, 54),
Rp(0, 1, 2, 3, 4, 55),
Rp(4, 0, 1, 2, 3, 56),
Rp(3, 4, 0, 1, 2, 57),
Rp(2, 3, 4, 0, 1, 58),
Rp(1, 2, 3, 4, 0, 59),
};
inline for (round2) |r| {
const t = s[(r.i - 3) & 0xf] ^ s[(r.i - 8) & 0xf] ^ s[(r.i - 14) & 0xf] ^ s[(r.i - 16) & 0xf];
s[r.i & 0xf] = math.rotl(u32, t, @as(u32, 1));
v[r.e] = v[r.e] +% math.rotl(u32, v[r.a], @as(u32, 5)) +% 0x8F1BBCDC +% s[r.i & 0xf] +% ((v[r.b] & v[r.c]) ^ (v[r.b] & v[r.d]) ^ (v[r.c] & v[r.d]));
v[r.b] = math.rotl(u32, v[r.b], @as(u32, 30));
}
const round3 = comptime [_]RoundParam{
Rp(0, 1, 2, 3, 4, 60),
Rp(4, 0, 1, 2, 3, 61),
Rp(3, 4, 0, 1, 2, 62),
Rp(2, 3, 4, 0, 1, 63),
Rp(1, 2, 3, 4, 0, 64),
Rp(0, 1, 2, 3, 4, 65),
Rp(4, 0, 1, 2, 3, 66),
Rp(3, 4, 0, 1, 2, 67),
Rp(2, 3, 4, 0, 1, 68),
Rp(1, 2, 3, 4, 0, 69),
Rp(0, 1, 2, 3, 4, 70),
Rp(4, 0, 1, 2, 3, 71),
Rp(3, 4, 0, 1, 2, 72),
Rp(2, 3, 4, 0, 1, 73),
Rp(1, 2, 3, 4, 0, 74),
Rp(0, 1, 2, 3, 4, 75),
Rp(4, 0, 1, 2, 3, 76),
Rp(3, 4, 0, 1, 2, 77),
Rp(2, 3, 4, 0, 1, 78),
Rp(1, 2, 3, 4, 0, 79),
};
inline for (round3) |r| {
const t = s[(r.i - 3) & 0xf] ^ s[(r.i - 8) & 0xf] ^ s[(r.i - 14) & 0xf] ^ s[(r.i - 16) & 0xf];
s[r.i & 0xf] = math.rotl(u32, t, @as(u32, 1));
v[r.e] = v[r.e] +% math.rotl(u32, v[r.a], @as(u32, 5)) +% 0xCA62C1D6 +% s[r.i & 0xf] +% (v[r.b] ^ v[r.c] ^ v[r.d]);
v[r.b] = math.rotl(u32, v[r.b], @as(u32, 30));
}
d.s[0] +%= v[0];
d.s[1] +%= v[1];
d.s[2] +%= v[2];
d.s[3] +%= v[3];
d.s[4] +%= v[4];
}
};
const htest = @import("test.zig");
test "sha1 single" {
htest.assertEqualHash(Sha1, "da39a3ee5e6b4b0d3255bfef95601890afd80709", "");
htest.assertEqualHash(Sha1, "a9993e364706816aba3e25717850c26c9cd0d89d", "abc");
htest.assertEqualHash(Sha1, "a49b2446a02c645bf419f995b67091253a04a259", "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu");
}
test "sha1 streaming" {
var h = Sha1.init();
var out: [20]u8 = undefined;
h.final(out[0..]);
htest.assertEqual("da39a3ee5e6b4b0d3255bfef95601890afd80709", out[0..]);
h = Sha1.init();
h.update("abc");
h.final(out[0..]);
htest.assertEqual("a9993e364706816aba3e25717850c26c9cd0d89d", out[0..]);
h = Sha1.init();
h.update("a");
h.update("b");
h.update("c");
h.final(out[0..]);
htest.assertEqual("a9993e364706816aba3e25717850c26c9cd0d89d", out[0..]);
}
test "sha1 aligned final" {
var block = [_]u8{0} ** Sha1.block_length;
var out: [Sha1.digest_length]u8 = undefined;
var h = Sha1.init();
h.update(&block);
h.final(out[0..]);
}