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crypto.salsa20: make the number of rounds a comptime parameter (#13442)
...instead of hard-coding it to 20. - This is consistent with the ChaCha implementation - NaCl and libsodium, that this API is designed to interop with, also support 8 and 12 round variants. The 12 round variant, in particular, provides the same security level as the 20 round variant, but is obviously faster. - scrypt currently uses its own non optimized version of Salsa, just because it use 8 rounds instead of 20. This will help remove code duplication. No behavior nor public API changes. The Salsa20 and XSalsa20 still represent the 20-round variant.
This commit is contained in:
Frank Denis
Andrew Kelley
parent
8d488246da
commit
30d392a87e
@ -147,6 +147,8 @@ pub const stream = struct {
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};
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pub const salsa = struct {
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pub const Salsa = @import("crypto/salsa20.zig").Salsa;
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pub const XSalsa = @import("crypto/salsa20.zig").XSalsa;
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pub const Salsa20 = @import("crypto/salsa20.zig").Salsa20;
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pub const XSalsa20 = @import("crypto/salsa20.zig").XSalsa20;
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};
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@ -14,297 +14,293 @@ const AuthenticationError = crypto.errors.AuthenticationError;
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const IdentityElementError = crypto.errors.IdentityElementError;
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const WeakPublicKeyError = crypto.errors.WeakPublicKeyError;
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const Salsa20VecImpl = struct {
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const Lane = @Vector(4, u32);
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const Half = @Vector(2, u32);
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const BlockVec = [4]Lane;
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/// The Salsa cipher with 20 rounds.
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pub const Salsa20 = Salsa(20);
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fn initContext(key: [8]u32, d: [4]u32) BlockVec {
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const c = "expand 32-byte k";
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const constant_le = comptime [4]u32{
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mem.readIntLittle(u32, c[0..4]),
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mem.readIntLittle(u32, c[4..8]),
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mem.readIntLittle(u32, c[8..12]),
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mem.readIntLittle(u32, c[12..16]),
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};
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return BlockVec{
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Lane{ key[0], key[1], key[2], key[3] },
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Lane{ key[4], key[5], key[6], key[7] },
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Lane{ constant_le[0], constant_le[1], constant_le[2], constant_le[3] },
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Lane{ d[0], d[1], d[2], d[3] },
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};
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}
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/// The XSalsa cipher with 20 rounds.
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pub const XSalsa20 = XSalsa(20);
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inline fn salsa20Core(x: *BlockVec, input: BlockVec, comptime feedback: bool) void {
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const n1n2n3n0 = Lane{ input[3][1], input[3][2], input[3][3], input[3][0] };
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const n1n2 = Half{ n1n2n3n0[0], n1n2n3n0[1] };
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const n3n0 = Half{ n1n2n3n0[2], n1n2n3n0[3] };
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const k0k1 = Half{ input[0][0], input[0][1] };
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const k2k3 = Half{ input[0][2], input[0][3] };
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const k4k5 = Half{ input[1][0], input[1][1] };
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const k6k7 = Half{ input[1][2], input[1][3] };
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const n0k0 = Half{ n3n0[1], k0k1[0] };
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const k0n0 = Half{ n0k0[1], n0k0[0] };
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const k4k5k0n0 = Lane{ k4k5[0], k4k5[1], k0n0[0], k0n0[1] };
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const k1k6 = Half{ k0k1[1], k6k7[0] };
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const k6k1 = Half{ k1k6[1], k1k6[0] };
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const n1n2k6k1 = Lane{ n1n2[0], n1n2[1], k6k1[0], k6k1[1] };
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const k7n3 = Half{ k6k7[1], n3n0[0] };
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const n3k7 = Half{ k7n3[1], k7n3[0] };
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const k2k3n3k7 = Lane{ k2k3[0], k2k3[1], n3k7[0], n3k7[1] };
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fn SalsaVecImpl(comptime rounds: comptime_int) type {
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return struct {
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const Lane = @Vector(4, u32);
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const Half = @Vector(2, u32);
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const BlockVec = [4]Lane;
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var diag0 = input[2];
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var diag1 = @shuffle(u32, k4k5k0n0, undefined, [_]i32{ 1, 2, 3, 0 });
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var diag2 = @shuffle(u32, n1n2k6k1, undefined, [_]i32{ 1, 2, 3, 0 });
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var diag3 = @shuffle(u32, k2k3n3k7, undefined, [_]i32{ 1, 2, 3, 0 });
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const start0 = diag0;
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const start1 = diag1;
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const start2 = diag2;
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const start3 = diag3;
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var i: usize = 0;
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while (i < 20) : (i += 2) {
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var a0 = diag1 +% diag0;
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diag3 ^= math.rotl(Lane, a0, 7);
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var a1 = diag0 +% diag3;
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diag2 ^= math.rotl(Lane, a1, 9);
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var a2 = diag3 +% diag2;
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diag1 ^= math.rotl(Lane, a2, 13);
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var a3 = diag2 +% diag1;
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diag0 ^= math.rotl(Lane, a3, 18);
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var diag3_shift = @shuffle(u32, diag3, undefined, [_]i32{ 3, 0, 1, 2 });
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var diag2_shift = @shuffle(u32, diag2, undefined, [_]i32{ 2, 3, 0, 1 });
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var diag1_shift = @shuffle(u32, diag1, undefined, [_]i32{ 1, 2, 3, 0 });
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diag3 = diag3_shift;
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diag2 = diag2_shift;
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diag1 = diag1_shift;
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a0 = diag3 +% diag0;
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diag1 ^= math.rotl(Lane, a0, 7);
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a1 = diag0 +% diag1;
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diag2 ^= math.rotl(Lane, a1, 9);
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a2 = diag1 +% diag2;
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diag3 ^= math.rotl(Lane, a2, 13);
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a3 = diag2 +% diag3;
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diag0 ^= math.rotl(Lane, a3, 18);
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diag1_shift = @shuffle(u32, diag1, undefined, [_]i32{ 3, 0, 1, 2 });
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diag2_shift = @shuffle(u32, diag2, undefined, [_]i32{ 2, 3, 0, 1 });
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diag3_shift = @shuffle(u32, diag3, undefined, [_]i32{ 1, 2, 3, 0 });
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diag1 = diag1_shift;
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diag2 = diag2_shift;
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diag3 = diag3_shift;
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fn initContext(key: [8]u32, d: [4]u32) BlockVec {
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const c = "expand 32-byte k";
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const constant_le = comptime [4]u32{
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mem.readIntLittle(u32, c[0..4]),
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mem.readIntLittle(u32, c[4..8]),
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mem.readIntLittle(u32, c[8..12]),
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mem.readIntLittle(u32, c[12..16]),
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};
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return BlockVec{
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Lane{ key[0], key[1], key[2], key[3] },
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Lane{ key[4], key[5], key[6], key[7] },
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Lane{ constant_le[0], constant_le[1], constant_le[2], constant_le[3] },
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Lane{ d[0], d[1], d[2], d[3] },
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};
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}
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if (feedback) {
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diag0 +%= start0;
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diag1 +%= start1;
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diag2 +%= start2;
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diag3 +%= start3;
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}
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inline fn salsaCore(x: *BlockVec, input: BlockVec, comptime feedback: bool) void {
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const n1n2n3n0 = Lane{ input[3][1], input[3][2], input[3][3], input[3][0] };
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const n1n2 = Half{ n1n2n3n0[0], n1n2n3n0[1] };
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const n3n0 = Half{ n1n2n3n0[2], n1n2n3n0[3] };
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const k0k1 = Half{ input[0][0], input[0][1] };
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const k2k3 = Half{ input[0][2], input[0][3] };
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const k4k5 = Half{ input[1][0], input[1][1] };
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const k6k7 = Half{ input[1][2], input[1][3] };
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const n0k0 = Half{ n3n0[1], k0k1[0] };
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const k0n0 = Half{ n0k0[1], n0k0[0] };
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const k4k5k0n0 = Lane{ k4k5[0], k4k5[1], k0n0[0], k0n0[1] };
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const k1k6 = Half{ k0k1[1], k6k7[0] };
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const k6k1 = Half{ k1k6[1], k1k6[0] };
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const n1n2k6k1 = Lane{ n1n2[0], n1n2[1], k6k1[0], k6k1[1] };
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const k7n3 = Half{ k6k7[1], n3n0[0] };
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const n3k7 = Half{ k7n3[1], k7n3[0] };
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const k2k3n3k7 = Lane{ k2k3[0], k2k3[1], n3k7[0], n3k7[1] };
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const x0x1x10x11 = Lane{ diag0[0], diag1[1], diag0[2], diag1[3] };
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const x12x13x6x7 = Lane{ diag1[0], diag2[1], diag1[2], diag2[3] };
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const x8x9x2x3 = Lane{ diag2[0], diag3[1], diag2[2], diag3[3] };
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const x4x5x14x15 = Lane{ diag3[0], diag0[1], diag3[2], diag0[3] };
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var diag0 = input[2];
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var diag1 = @shuffle(u32, k4k5k0n0, undefined, [_]i32{ 1, 2, 3, 0 });
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var diag2 = @shuffle(u32, n1n2k6k1, undefined, [_]i32{ 1, 2, 3, 0 });
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var diag3 = @shuffle(u32, k2k3n3k7, undefined, [_]i32{ 1, 2, 3, 0 });
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x[0] = Lane{ x0x1x10x11[0], x0x1x10x11[1], x8x9x2x3[2], x8x9x2x3[3] };
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x[1] = Lane{ x4x5x14x15[0], x4x5x14x15[1], x12x13x6x7[2], x12x13x6x7[3] };
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x[2] = Lane{ x8x9x2x3[0], x8x9x2x3[1], x0x1x10x11[2], x0x1x10x11[3] };
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x[3] = Lane{ x12x13x6x7[0], x12x13x6x7[1], x4x5x14x15[2], x4x5x14x15[3] };
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}
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const start0 = diag0;
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const start1 = diag1;
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const start2 = diag2;
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const start3 = diag3;
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fn hashToBytes(out: *[64]u8, x: BlockVec) void {
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var i: usize = 0;
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while (i < 4) : (i += 1) {
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mem.writeIntLittle(u32, out[16 * i + 0 ..][0..4], x[i][0]);
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mem.writeIntLittle(u32, out[16 * i + 4 ..][0..4], x[i][1]);
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mem.writeIntLittle(u32, out[16 * i + 8 ..][0..4], x[i][2]);
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mem.writeIntLittle(u32, out[16 * i + 12 ..][0..4], x[i][3]);
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}
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}
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var i: usize = 0;
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while (i < rounds) : (i += 2) {
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diag3 ^= math.rotl(Lane, diag1 +% diag0, 7);
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diag2 ^= math.rotl(Lane, diag0 +% diag3, 9);
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diag1 ^= math.rotl(Lane, diag3 +% diag2, 13);
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diag0 ^= math.rotl(Lane, diag2 +% diag1, 18);
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fn salsa20Xor(out: []u8, in: []const u8, key: [8]u32, d: [4]u32) void {
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var ctx = initContext(key, d);
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var x: BlockVec = undefined;
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var buf: [64]u8 = undefined;
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var i: usize = 0;
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while (i + 64 <= in.len) : (i += 64) {
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salsa20Core(x[0..], ctx, true);
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hashToBytes(buf[0..], x);
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var xout = out[i..];
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const xin = in[i..];
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var j: usize = 0;
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while (j < 64) : (j += 1) {
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xout[j] = xin[j];
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diag3 = @shuffle(u32, diag3, undefined, [_]i32{ 3, 0, 1, 2 });
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diag2 = @shuffle(u32, diag2, undefined, [_]i32{ 2, 3, 0, 1 });
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diag1 = @shuffle(u32, diag1, undefined, [_]i32{ 1, 2, 3, 0 });
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diag1 ^= math.rotl(Lane, diag3 +% diag0, 7);
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diag2 ^= math.rotl(Lane, diag0 +% diag1, 9);
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diag3 ^= math.rotl(Lane, diag1 +% diag2, 13);
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diag0 ^= math.rotl(Lane, diag2 +% diag3, 18);
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diag1 = @shuffle(u32, diag1, undefined, [_]i32{ 3, 0, 1, 2 });
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diag2 = @shuffle(u32, diag2, undefined, [_]i32{ 2, 3, 0, 1 });
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diag3 = @shuffle(u32, diag3, undefined, [_]i32{ 1, 2, 3, 0 });
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}
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j = 0;
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while (j < 64) : (j += 1) {
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xout[j] ^= buf[j];
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if (feedback) {
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diag0 +%= start0;
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diag1 +%= start1;
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diag2 +%= start2;
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diag3 +%= start3;
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}
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ctx[3][2] +%= 1;
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if (ctx[3][2] == 0) {
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ctx[3][3] += 1;
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const x0x1x10x11 = Lane{ diag0[0], diag1[1], diag0[2], diag1[3] };
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const x12x13x6x7 = Lane{ diag1[0], diag2[1], diag1[2], diag2[3] };
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const x8x9x2x3 = Lane{ diag2[0], diag3[1], diag2[2], diag3[3] };
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const x4x5x14x15 = Lane{ diag3[0], diag0[1], diag3[2], diag0[3] };
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x[0] = Lane{ x0x1x10x11[0], x0x1x10x11[1], x8x9x2x3[2], x8x9x2x3[3] };
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x[1] = Lane{ x4x5x14x15[0], x4x5x14x15[1], x12x13x6x7[2], x12x13x6x7[3] };
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x[2] = Lane{ x8x9x2x3[0], x8x9x2x3[1], x0x1x10x11[2], x0x1x10x11[3] };
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x[3] = Lane{ x12x13x6x7[0], x12x13x6x7[1], x4x5x14x15[2], x4x5x14x15[3] };
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}
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fn hashToBytes(out: *[64]u8, x: BlockVec) void {
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var i: usize = 0;
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while (i < 4) : (i += 1) {
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mem.writeIntLittle(u32, out[16 * i + 0 ..][0..4], x[i][0]);
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mem.writeIntLittle(u32, out[16 * i + 4 ..][0..4], x[i][1]);
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mem.writeIntLittle(u32, out[16 * i + 8 ..][0..4], x[i][2]);
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mem.writeIntLittle(u32, out[16 * i + 12 ..][0..4], x[i][3]);
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}
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}
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if (i < in.len) {
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salsa20Core(x[0..], ctx, true);
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hashToBytes(buf[0..], x);
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var xout = out[i..];
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const xin = in[i..];
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var j: usize = 0;
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while (j < in.len % 64) : (j += 1) {
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xout[j] = xin[j] ^ buf[j];
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fn salsaXor(out: []u8, in: []const u8, key: [8]u32, d: [4]u32) void {
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var ctx = initContext(key, d);
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var x: BlockVec = undefined;
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var buf: [64]u8 = undefined;
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var i: usize = 0;
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while (i + 64 <= in.len) : (i += 64) {
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salsaCore(x[0..], ctx, true);
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hashToBytes(buf[0..], x);
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var xout = out[i..];
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const xin = in[i..];
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var j: usize = 0;
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while (j < 64) : (j += 1) {
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xout[j] = xin[j];
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}
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j = 0;
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while (j < 64) : (j += 1) {
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xout[j] ^= buf[j];
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}
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ctx[3][2] +%= 1;
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if (ctx[3][2] == 0) {
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ctx[3][3] += 1;
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}
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}
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if (i < in.len) {
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salsaCore(x[0..], ctx, true);
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hashToBytes(buf[0..], x);
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var xout = out[i..];
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const xin = in[i..];
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var j: usize = 0;
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while (j < in.len % 64) : (j += 1) {
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xout[j] = xin[j] ^ buf[j];
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}
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}
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}
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}
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fn hsalsa20(input: [16]u8, key: [32]u8) [32]u8 {
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var c: [4]u32 = undefined;
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for (c) |_, i| {
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c[i] = mem.readIntLittle(u32, input[4 * i ..][0..4]);
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fn hsalsa(input: [16]u8, key: [32]u8) [32]u8 {
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var c: [4]u32 = undefined;
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for (c) |_, i| {
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c[i] = mem.readIntLittle(u32, input[4 * i ..][0..4]);
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}
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const ctx = initContext(keyToWords(key), c);
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var x: BlockVec = undefined;
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salsaCore(x[0..], ctx, false);
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var out: [32]u8 = undefined;
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mem.writeIntLittle(u32, out[0..4], x[0][0]);
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mem.writeIntLittle(u32, out[4..8], x[1][1]);
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mem.writeIntLittle(u32, out[8..12], x[2][2]);
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mem.writeIntLittle(u32, out[12..16], x[3][3]);
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mem.writeIntLittle(u32, out[16..20], x[1][2]);
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mem.writeIntLittle(u32, out[20..24], x[1][3]);
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mem.writeIntLittle(u32, out[24..28], x[2][0]);
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mem.writeIntLittle(u32, out[28..32], x[2][1]);
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return out;
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}
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const ctx = initContext(keyToWords(key), c);
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var x: BlockVec = undefined;
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salsa20Core(x[0..], ctx, false);
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var out: [32]u8 = undefined;
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mem.writeIntLittle(u32, out[0..4], x[0][0]);
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mem.writeIntLittle(u32, out[4..8], x[1][1]);
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mem.writeIntLittle(u32, out[8..12], x[2][2]);
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mem.writeIntLittle(u32, out[12..16], x[3][3]);
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mem.writeIntLittle(u32, out[16..20], x[1][2]);
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mem.writeIntLittle(u32, out[20..24], x[1][3]);
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mem.writeIntLittle(u32, out[24..28], x[2][0]);
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mem.writeIntLittle(u32, out[28..32], x[2][1]);
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return out;
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}
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};
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const Salsa20NonVecImpl = struct {
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const BlockVec = [16]u32;
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|
||||
fn initContext(key: [8]u32, d: [4]u32) BlockVec {
|
||||
const c = "expand 32-byte k";
|
||||
const constant_le = comptime [4]u32{
|
||||
mem.readIntLittle(u32, c[0..4]),
|
||||
mem.readIntLittle(u32, c[4..8]),
|
||||
mem.readIntLittle(u32, c[8..12]),
|
||||
mem.readIntLittle(u32, c[12..16]),
|
||||
};
|
||||
return BlockVec{
|
||||
constant_le[0], key[0], key[1], key[2],
|
||||
key[3], constant_le[1], d[0], d[1],
|
||||
d[2], d[3], constant_le[2], key[4],
|
||||
key[5], key[6], key[7], constant_le[3],
|
||||
};
|
||||
}
|
||||
|
||||
const QuarterRound = struct {
|
||||
a: usize,
|
||||
b: usize,
|
||||
c: usize,
|
||||
d: u6,
|
||||
};
|
||||
}
|
||||
|
||||
inline fn Rp(a: usize, b: usize, c: usize, d: u6) QuarterRound {
|
||||
return QuarterRound{
|
||||
.a = a,
|
||||
.b = b,
|
||||
.c = c,
|
||||
.d = d,
|
||||
fn SalsaNonVecImpl(comptime rounds: comptime_int) type {
|
||||
return struct {
|
||||
const BlockVec = [16]u32;
|
||||
|
||||
fn initContext(key: [8]u32, d: [4]u32) BlockVec {
|
||||
const c = "expand 32-byte k";
|
||||
const constant_le = comptime [4]u32{
|
||||
mem.readIntLittle(u32, c[0..4]),
|
||||
mem.readIntLittle(u32, c[4..8]),
|
||||
mem.readIntLittle(u32, c[8..12]),
|
||||
mem.readIntLittle(u32, c[12..16]),
|
||||
};
|
||||
return BlockVec{
|
||||
constant_le[0], key[0], key[1], key[2],
|
||||
key[3], constant_le[1], d[0], d[1],
|
||||
d[2], d[3], constant_le[2], key[4],
|
||||
key[5], key[6], key[7], constant_le[3],
|
||||
};
|
||||
}
|
||||
|
||||
const QuarterRound = struct {
|
||||
a: usize,
|
||||
b: usize,
|
||||
c: usize,
|
||||
d: u6,
|
||||
};
|
||||
}
|
||||
|
||||
inline fn salsa20Core(x: *BlockVec, input: BlockVec, comptime feedback: bool) void {
|
||||
const arx_steps = comptime [_]QuarterRound{
|
||||
Rp(4, 0, 12, 7), Rp(8, 4, 0, 9), Rp(12, 8, 4, 13), Rp(0, 12, 8, 18),
|
||||
Rp(9, 5, 1, 7), Rp(13, 9, 5, 9), Rp(1, 13, 9, 13), Rp(5, 1, 13, 18),
|
||||
Rp(14, 10, 6, 7), Rp(2, 14, 10, 9), Rp(6, 2, 14, 13), Rp(10, 6, 2, 18),
|
||||
Rp(3, 15, 11, 7), Rp(7, 3, 15, 9), Rp(11, 7, 3, 13), Rp(15, 11, 7, 18),
|
||||
Rp(1, 0, 3, 7), Rp(2, 1, 0, 9), Rp(3, 2, 1, 13), Rp(0, 3, 2, 18),
|
||||
Rp(6, 5, 4, 7), Rp(7, 6, 5, 9), Rp(4, 7, 6, 13), Rp(5, 4, 7, 18),
|
||||
Rp(11, 10, 9, 7), Rp(8, 11, 10, 9), Rp(9, 8, 11, 13), Rp(10, 9, 8, 18),
|
||||
Rp(12, 15, 14, 7), Rp(13, 12, 15, 9), Rp(14, 13, 12, 13), Rp(15, 14, 13, 18),
|
||||
};
|
||||
x.* = input;
|
||||
var j: usize = 0;
|
||||
while (j < 20) : (j += 2) {
|
||||
inline for (arx_steps) |r| {
|
||||
x[r.a] ^= math.rotl(u32, x[r.b] +% x[r.c], r.d);
|
||||
}
|
||||
inline fn Rp(a: usize, b: usize, c: usize, d: u6) QuarterRound {
|
||||
return QuarterRound{
|
||||
.a = a,
|
||||
.b = b,
|
||||
.c = c,
|
||||
.d = d,
|
||||
};
|
||||
}
|
||||
if (feedback) {
|
||||
j = 0;
|
||||
while (j < 16) : (j += 1) {
|
||||
x[j] +%= input[j];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn hashToBytes(out: *[64]u8, x: BlockVec) void {
|
||||
for (x) |w, i| {
|
||||
mem.writeIntLittle(u32, out[i * 4 ..][0..4], w);
|
||||
}
|
||||
}
|
||||
|
||||
fn salsa20Xor(out: []u8, in: []const u8, key: [8]u32, d: [4]u32) void {
|
||||
var ctx = initContext(key, d);
|
||||
var x: BlockVec = undefined;
|
||||
var buf: [64]u8 = undefined;
|
||||
var i: usize = 0;
|
||||
while (i + 64 <= in.len) : (i += 64) {
|
||||
salsa20Core(x[0..], ctx, true);
|
||||
hashToBytes(buf[0..], x);
|
||||
var xout = out[i..];
|
||||
const xin = in[i..];
|
||||
inline fn salsaCore(x: *BlockVec, input: BlockVec, comptime feedback: bool) void {
|
||||
const arx_steps = comptime [_]QuarterRound{
|
||||
Rp(4, 0, 12, 7), Rp(8, 4, 0, 9), Rp(12, 8, 4, 13), Rp(0, 12, 8, 18),
|
||||
Rp(9, 5, 1, 7), Rp(13, 9, 5, 9), Rp(1, 13, 9, 13), Rp(5, 1, 13, 18),
|
||||
Rp(14, 10, 6, 7), Rp(2, 14, 10, 9), Rp(6, 2, 14, 13), Rp(10, 6, 2, 18),
|
||||
Rp(3, 15, 11, 7), Rp(7, 3, 15, 9), Rp(11, 7, 3, 13), Rp(15, 11, 7, 18),
|
||||
Rp(1, 0, 3, 7), Rp(2, 1, 0, 9), Rp(3, 2, 1, 13), Rp(0, 3, 2, 18),
|
||||
Rp(6, 5, 4, 7), Rp(7, 6, 5, 9), Rp(4, 7, 6, 13), Rp(5, 4, 7, 18),
|
||||
Rp(11, 10, 9, 7), Rp(8, 11, 10, 9), Rp(9, 8, 11, 13), Rp(10, 9, 8, 18),
|
||||
Rp(12, 15, 14, 7), Rp(13, 12, 15, 9), Rp(14, 13, 12, 13), Rp(15, 14, 13, 18),
|
||||
};
|
||||
x.* = input;
|
||||
var j: usize = 0;
|
||||
while (j < 64) : (j += 1) {
|
||||
xout[j] = xin[j];
|
||||
while (j < rounds) : (j += 2) {
|
||||
inline for (arx_steps) |r| {
|
||||
x[r.a] ^= math.rotl(u32, x[r.b] +% x[r.c], r.d);
|
||||
}
|
||||
}
|
||||
j = 0;
|
||||
while (j < 64) : (j += 1) {
|
||||
xout[j] ^= buf[j];
|
||||
}
|
||||
ctx[9] += @boolToInt(@addWithOverflow(u32, ctx[8], 1, &ctx[8]));
|
||||
}
|
||||
if (i < in.len) {
|
||||
salsa20Core(x[0..], ctx, true);
|
||||
hashToBytes(buf[0..], x);
|
||||
|
||||
var xout = out[i..];
|
||||
const xin = in[i..];
|
||||
var j: usize = 0;
|
||||
while (j < in.len % 64) : (j += 1) {
|
||||
xout[j] = xin[j] ^ buf[j];
|
||||
if (feedback) {
|
||||
j = 0;
|
||||
while (j < 16) : (j += 1) {
|
||||
x[j] +%= input[j];
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn hsalsa20(input: [16]u8, key: [32]u8) [32]u8 {
|
||||
var c: [4]u32 = undefined;
|
||||
for (c) |_, i| {
|
||||
c[i] = mem.readIntLittle(u32, input[4 * i ..][0..4]);
|
||||
fn hashToBytes(out: *[64]u8, x: BlockVec) void {
|
||||
for (x) |w, i| {
|
||||
mem.writeIntLittle(u32, out[i * 4 ..][0..4], w);
|
||||
}
|
||||
}
|
||||
const ctx = initContext(keyToWords(key), c);
|
||||
var x: BlockVec = undefined;
|
||||
salsa20Core(x[0..], ctx, false);
|
||||
var out: [32]u8 = undefined;
|
||||
mem.writeIntLittle(u32, out[0..4], x[0]);
|
||||
mem.writeIntLittle(u32, out[4..8], x[5]);
|
||||
mem.writeIntLittle(u32, out[8..12], x[10]);
|
||||
mem.writeIntLittle(u32, out[12..16], x[15]);
|
||||
mem.writeIntLittle(u32, out[16..20], x[6]);
|
||||
mem.writeIntLittle(u32, out[20..24], x[7]);
|
||||
mem.writeIntLittle(u32, out[24..28], x[8]);
|
||||
mem.writeIntLittle(u32, out[28..32], x[9]);
|
||||
return out;
|
||||
}
|
||||
};
|
||||
|
||||
const Salsa20Impl = if (builtin.cpu.arch == .x86_64) Salsa20VecImpl else Salsa20NonVecImpl;
|
||||
fn salsaXor(out: []u8, in: []const u8, key: [8]u32, d: [4]u32) void {
|
||||
var ctx = initContext(key, d);
|
||||
var x: BlockVec = undefined;
|
||||
var buf: [64]u8 = undefined;
|
||||
var i: usize = 0;
|
||||
while (i + 64 <= in.len) : (i += 64) {
|
||||
salsaCore(x[0..], ctx, true);
|
||||
hashToBytes(buf[0..], x);
|
||||
var xout = out[i..];
|
||||
const xin = in[i..];
|
||||
var j: usize = 0;
|
||||
while (j < 64) : (j += 1) {
|
||||
xout[j] = xin[j];
|
||||
}
|
||||
j = 0;
|
||||
while (j < 64) : (j += 1) {
|
||||
xout[j] ^= buf[j];
|
||||
}
|
||||
ctx[9] += @boolToInt(@addWithOverflow(u32, ctx[8], 1, &ctx[8]));
|
||||
}
|
||||
if (i < in.len) {
|
||||
salsaCore(x[0..], ctx, true);
|
||||
hashToBytes(buf[0..], x);
|
||||
|
||||
var xout = out[i..];
|
||||
const xin = in[i..];
|
||||
var j: usize = 0;
|
||||
while (j < in.len % 64) : (j += 1) {
|
||||
xout[j] = xin[j] ^ buf[j];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn hsalsa(input: [16]u8, key: [32]u8) [32]u8 {
|
||||
var c: [4]u32 = undefined;
|
||||
for (c) |_, i| {
|
||||
c[i] = mem.readIntLittle(u32, input[4 * i ..][0..4]);
|
||||
}
|
||||
const ctx = initContext(keyToWords(key), c);
|
||||
var x: BlockVec = undefined;
|
||||
salsaCore(x[0..], ctx, false);
|
||||
var out: [32]u8 = undefined;
|
||||
mem.writeIntLittle(u32, out[0..4], x[0]);
|
||||
mem.writeIntLittle(u32, out[4..8], x[5]);
|
||||
mem.writeIntLittle(u32, out[8..12], x[10]);
|
||||
mem.writeIntLittle(u32, out[12..16], x[15]);
|
||||
mem.writeIntLittle(u32, out[16..20], x[6]);
|
||||
mem.writeIntLittle(u32, out[20..24], x[7]);
|
||||
mem.writeIntLittle(u32, out[24..28], x[8]);
|
||||
mem.writeIntLittle(u32, out[28..32], x[9]);
|
||||
return out;
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
const SalsaImpl = if (builtin.cpu.arch == .x86_64) SalsaVecImpl else SalsaNonVecImpl;
|
||||
|
||||
fn keyToWords(key: [32]u8) [8]u32 {
|
||||
var k: [8]u32 = undefined;
|
||||
@ -315,52 +311,56 @@ fn keyToWords(key: [32]u8) [8]u32 {
|
||||
return k;
|
||||
}
|
||||
|
||||
fn extend(key: [32]u8, nonce: [24]u8) struct { key: [32]u8, nonce: [8]u8 } {
|
||||
fn extend(comptime rounds: comptime_int, key: [32]u8, nonce: [24]u8) struct { key: [32]u8, nonce: [8]u8 } {
|
||||
return .{
|
||||
.key = Salsa20Impl.hsalsa20(nonce[0..16].*, key),
|
||||
.key = SalsaImpl(rounds).hsalsa(nonce[0..16].*, key),
|
||||
.nonce = nonce[16..24].*,
|
||||
};
|
||||
}
|
||||
|
||||
/// The Salsa20 stream cipher.
|
||||
pub const Salsa20 = struct {
|
||||
/// Nonce length in bytes.
|
||||
pub const nonce_length = 8;
|
||||
/// Key length in bytes.
|
||||
pub const key_length = 32;
|
||||
/// The Salsa stream cipher.
|
||||
pub fn Salsa(comptime rounds: comptime_int) type {
|
||||
return struct {
|
||||
/// Nonce length in bytes.
|
||||
pub const nonce_length = 8;
|
||||
/// Key length in bytes.
|
||||
pub const key_length = 32;
|
||||
|
||||
/// Add the output of the Salsa20 stream cipher to `in` and stores the result into `out`.
|
||||
/// WARNING: This function doesn't provide authenticated encryption.
|
||||
/// Using the AEAD or one of the `box` versions is usually preferred.
|
||||
pub fn xor(out: []u8, in: []const u8, counter: u64, key: [key_length]u8, nonce: [nonce_length]u8) void {
|
||||
debug.assert(in.len == out.len);
|
||||
/// Add the output of the Salsa stream cipher to `in` and stores the result into `out`.
|
||||
/// WARNING: This function doesn't provide authenticated encryption.
|
||||
/// Using the AEAD or one of the `box` versions is usually preferred.
|
||||
pub fn xor(out: []u8, in: []const u8, counter: u64, key: [key_length]u8, nonce: [nonce_length]u8) void {
|
||||
debug.assert(in.len == out.len);
|
||||
|
||||
var d: [4]u32 = undefined;
|
||||
d[0] = mem.readIntLittle(u32, nonce[0..4]);
|
||||
d[1] = mem.readIntLittle(u32, nonce[4..8]);
|
||||
d[2] = @truncate(u32, counter);
|
||||
d[3] = @truncate(u32, counter >> 32);
|
||||
Salsa20Impl.salsa20Xor(out, in, keyToWords(key), d);
|
||||
}
|
||||
};
|
||||
var d: [4]u32 = undefined;
|
||||
d[0] = mem.readIntLittle(u32, nonce[0..4]);
|
||||
d[1] = mem.readIntLittle(u32, nonce[4..8]);
|
||||
d[2] = @truncate(u32, counter);
|
||||
d[3] = @truncate(u32, counter >> 32);
|
||||
SalsaImpl(rounds).salsaXor(out, in, keyToWords(key), d);
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
/// The XSalsa20 stream cipher.
|
||||
pub const XSalsa20 = struct {
|
||||
/// Nonce length in bytes.
|
||||
pub const nonce_length = 24;
|
||||
/// Key length in bytes.
|
||||
pub const key_length = 32;
|
||||
/// The XSalsa stream cipher.
|
||||
pub fn XSalsa(comptime rounds: comptime_int) type {
|
||||
return struct {
|
||||
/// Nonce length in bytes.
|
||||
pub const nonce_length = 24;
|
||||
/// Key length in bytes.
|
||||
pub const key_length = 32;
|
||||
|
||||
/// Add the output of the XSalsa20 stream cipher to `in` and stores the result into `out`.
|
||||
/// WARNING: This function doesn't provide authenticated encryption.
|
||||
/// Using the AEAD or one of the `box` versions is usually preferred.
|
||||
pub fn xor(out: []u8, in: []const u8, counter: u64, key: [key_length]u8, nonce: [nonce_length]u8) void {
|
||||
const extended = extend(key, nonce);
|
||||
Salsa20.xor(out, in, counter, extended.key, extended.nonce);
|
||||
}
|
||||
};
|
||||
/// Add the output of the XSalsa stream cipher to `in` and stores the result into `out`.
|
||||
/// WARNING: This function doesn't provide authenticated encryption.
|
||||
/// Using the AEAD or one of the `box` versions is usually preferred.
|
||||
pub fn xor(out: []u8, in: []const u8, counter: u64, key: [key_length]u8, nonce: [nonce_length]u8) void {
|
||||
const extended = extend(rounds, key, nonce);
|
||||
Salsa(rounds).xor(out, in, counter, extended.key, extended.nonce);
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
/// The XSalsa20 stream cipher, combined with the Poly1305 MAC
|
||||
/// The XSalsa stream cipher, combined with the Poly1305 MAC
|
||||
pub const XSalsa20Poly1305 = struct {
|
||||
/// Authentication tag length in bytes.
|
||||
pub const tag_length = Poly1305.mac_length;
|
||||
@ -369,6 +369,8 @@ pub const XSalsa20Poly1305 = struct {
|
||||
/// Key length in bytes.
|
||||
pub const key_length = XSalsa20.key_length;
|
||||
|
||||
const rounds = 20;
|
||||
|
||||
/// c: ciphertext: output buffer should be of size m.len
|
||||
/// tag: authentication tag: output MAC
|
||||
/// m: message
|
||||
@ -377,7 +379,7 @@ pub const XSalsa20Poly1305 = struct {
|
||||
/// k: private key
|
||||
pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, k: [key_length]u8) void {
|
||||
debug.assert(c.len == m.len);
|
||||
const extended = extend(k, npub);
|
||||
const extended = extend(rounds, k, npub);
|
||||
var block0 = [_]u8{0} ** 64;
|
||||
const mlen0 = math.min(32, m.len);
|
||||
mem.copy(u8, block0[32..][0..mlen0], m[0..mlen0]);
|
||||
@ -398,7 +400,7 @@ pub const XSalsa20Poly1305 = struct {
|
||||
/// k: private key
|
||||
pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, k: [key_length]u8) AuthenticationError!void {
|
||||
debug.assert(c.len == m.len);
|
||||
const extended = extend(k, npub);
|
||||
const extended = extend(rounds, k, npub);
|
||||
var block0 = [_]u8{0} ** 64;
|
||||
const mlen0 = math.min(32, c.len);
|
||||
mem.copy(u8, block0[32..][0..mlen0], c[0..mlen0]);
|
||||
@ -482,7 +484,7 @@ pub const Box = struct {
|
||||
pub fn createSharedSecret(public_key: [public_length]u8, secret_key: [secret_length]u8) (IdentityElementError || WeakPublicKeyError)![shared_length]u8 {
|
||||
const p = try X25519.scalarmult(secret_key, public_key);
|
||||
const zero = [_]u8{0} ** 16;
|
||||
return Salsa20Impl.hsalsa20(zero, p);
|
||||
return SalsaImpl(20).hsalsa(zero, p);
|
||||
}
|
||||
|
||||
/// Encrypt and authenticate a message using a recipient's public key `public_key` and a sender's `secret_key`.
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user