zig/lib/std/crypto/aegis.zig
Frank Denis 10f2d62789
std/crypto: use finer-grained error sets in function signatures (#8558)
std/crypto: use finer-grained error sets in function signatures

Returning the `crypto.Error` error set for all crypto operations
was very convenient to ensure that errors were used consistently,
and to avoid having multiple error names for the same thing.

The flipside is that callers were forced to always handle all
possible errors, even those that could never be returned by a
function.

This PR makes all functions return union sets of the actual errors
they can return.

The error sets themselves are all limited to a single error.

Larger sets are useful for platform-specific APIs, but we don't have
any of these in `std/crypto`, and I couldn't find any meaningful way
to build larger sets.
2021-04-20 19:57:27 +02:00

455 lines
18 KiB
Zig

// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2021 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 std = @import("std");
const mem = std.mem;
const assert = std.debug.assert;
const AesBlock = std.crypto.core.aes.Block;
const AuthenticationError = std.crypto.errors.AuthenticationError;
const State128L = struct {
blocks: [8]AesBlock,
fn init(key: [16]u8, nonce: [16]u8) State128L {
const c1 = AesBlock.fromBytes(&[16]u8{ 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1, 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd });
const c2 = AesBlock.fromBytes(&[16]u8{ 0x0, 0x1, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62 });
const key_block = AesBlock.fromBytes(&key);
const nonce_block = AesBlock.fromBytes(&nonce);
const blocks = [8]AesBlock{
key_block.xorBlocks(nonce_block),
c1,
c2,
c1,
key_block.xorBlocks(nonce_block),
key_block.xorBlocks(c2),
key_block.xorBlocks(c1),
key_block.xorBlocks(c2),
};
var state = State128L{ .blocks = blocks };
var i: usize = 0;
while (i < 10) : (i += 1) {
state.update(nonce_block, key_block);
}
return state;
}
fn update(state: *State128L, d1: AesBlock, d2: AesBlock) callconv(.Inline) void {
const blocks = &state.blocks;
const tmp = blocks[7];
comptime var i: usize = 7;
inline while (i > 0) : (i -= 1) {
blocks[i] = blocks[i - 1].encrypt(blocks[i]);
}
blocks[0] = tmp.encrypt(blocks[0]);
blocks[0] = blocks[0].xorBlocks(d1);
blocks[4] = blocks[4].xorBlocks(d2);
}
fn enc(state: *State128L, dst: *[32]u8, src: *const [32]u8) void {
const blocks = &state.blocks;
const msg0 = AesBlock.fromBytes(src[0..16]);
const msg1 = AesBlock.fromBytes(src[16..32]);
var tmp0 = msg0.xorBlocks(blocks[6]).xorBlocks(blocks[1]);
var tmp1 = msg1.xorBlocks(blocks[2]).xorBlocks(blocks[5]);
tmp0 = tmp0.xorBlocks(blocks[2].andBlocks(blocks[3]));
tmp1 = tmp1.xorBlocks(blocks[6].andBlocks(blocks[7]));
dst[0..16].* = tmp0.toBytes();
dst[16..32].* = tmp1.toBytes();
state.update(msg0, msg1);
}
fn dec(state: *State128L, dst: *[32]u8, src: *const [32]u8) void {
const blocks = &state.blocks;
var msg0 = AesBlock.fromBytes(src[0..16]).xorBlocks(blocks[6]).xorBlocks(blocks[1]);
var msg1 = AesBlock.fromBytes(src[16..32]).xorBlocks(blocks[2]).xorBlocks(blocks[5]);
msg0 = msg0.xorBlocks(blocks[2].andBlocks(blocks[3]));
msg1 = msg1.xorBlocks(blocks[6].andBlocks(blocks[7]));
dst[0..16].* = msg0.toBytes();
dst[16..32].* = msg1.toBytes();
state.update(msg0, msg1);
}
fn mac(state: *State128L, adlen: usize, mlen: usize) [16]u8 {
const blocks = &state.blocks;
var sizes: [16]u8 = undefined;
mem.writeIntLittle(u64, sizes[0..8], adlen * 8);
mem.writeIntLittle(u64, sizes[8..16], mlen * 8);
const tmp = AesBlock.fromBytes(&sizes).xorBlocks(blocks[2]);
var i: usize = 0;
while (i < 7) : (i += 1) {
state.update(tmp, tmp);
}
return blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4])
.xorBlocks(blocks[5]).xorBlocks(blocks[6]).toBytes();
}
};
/// AEGIS is a very fast authenticated encryption system built on top of the core AES function.
///
/// The 128L variant of AEGIS has a 128 bit key, a 128 bit nonce, and processes 256 bit message blocks.
/// It was designed to fully exploit the parallelism and built-in AES support of recent Intel and ARM CPUs.
///
/// https://competitions.cr.yp.to/round3/aegisv11.pdf
pub const Aegis128L = struct {
pub const tag_length = 16;
pub const nonce_length = 16;
pub const key_length = 16;
/// c: ciphertext: output buffer should be of size m.len
/// tag: authentication tag: output MAC
/// m: message
/// ad: Associated Data
/// npub: public nonce
/// k: private key
pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) void {
assert(c.len == m.len);
var state = State128L.init(key, npub);
var src: [32]u8 align(16) = undefined;
var dst: [32]u8 align(16) = undefined;
var i: usize = 0;
while (i + 32 <= ad.len) : (i += 32) {
state.enc(&dst, ad[i..][0..32]);
}
if (ad.len % 32 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. ad.len % 32], ad[i .. i + ad.len % 32]);
state.enc(&dst, &src);
}
i = 0;
while (i + 32 <= m.len) : (i += 32) {
state.enc(c[i..][0..32], m[i..][0..32]);
}
if (m.len % 32 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. m.len % 32], m[i .. i + m.len % 32]);
state.enc(&dst, &src);
mem.copy(u8, c[i .. i + m.len % 32], dst[0 .. m.len % 32]);
}
tag.* = state.mac(ad.len, m.len);
}
/// m: message: output buffer should be of size c.len
/// c: ciphertext
/// tag: authentication tag
/// ad: Associated Data
/// npub: public nonce
/// k: private key
pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) AuthenticationError!void {
assert(c.len == m.len);
var state = State128L.init(key, npub);
var src: [32]u8 align(16) = undefined;
var dst: [32]u8 align(16) = undefined;
var i: usize = 0;
while (i + 32 <= ad.len) : (i += 32) {
state.enc(&dst, ad[i..][0..32]);
}
if (ad.len % 32 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. ad.len % 32], ad[i .. i + ad.len % 32]);
state.enc(&dst, &src);
}
i = 0;
while (i + 32 <= m.len) : (i += 32) {
state.dec(m[i..][0..32], c[i..][0..32]);
}
if (m.len % 32 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. m.len % 32], c[i .. i + m.len % 32]);
state.dec(&dst, &src);
mem.copy(u8, m[i .. i + m.len % 32], dst[0 .. m.len % 32]);
mem.set(u8, dst[0 .. m.len % 32], 0);
const blocks = &state.blocks;
blocks[0] = blocks[0].xorBlocks(AesBlock.fromBytes(dst[0..16]));
blocks[4] = blocks[4].xorBlocks(AesBlock.fromBytes(dst[16..32]));
}
const computed_tag = state.mac(ad.len, m.len);
var acc: u8 = 0;
for (computed_tag) |_, j| {
acc |= (computed_tag[j] ^ tag[j]);
}
if (acc != 0) {
mem.set(u8, m, 0xaa);
return error.AuthenticationFailed;
}
}
};
const State256 = struct {
blocks: [6]AesBlock,
fn init(key: [32]u8, nonce: [32]u8) State256 {
const c1 = AesBlock.fromBytes(&[16]u8{ 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1, 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd });
const c2 = AesBlock.fromBytes(&[16]u8{ 0x0, 0x1, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62 });
const key_block1 = AesBlock.fromBytes(key[0..16]);
const key_block2 = AesBlock.fromBytes(key[16..32]);
const nonce_block1 = AesBlock.fromBytes(nonce[0..16]);
const nonce_block2 = AesBlock.fromBytes(nonce[16..32]);
const kxn1 = key_block1.xorBlocks(nonce_block1);
const kxn2 = key_block2.xorBlocks(nonce_block2);
const blocks = [6]AesBlock{
kxn1,
kxn2,
c1,
c2,
key_block1.xorBlocks(c2),
key_block2.xorBlocks(c1),
};
var state = State256{ .blocks = blocks };
var i: usize = 0;
while (i < 4) : (i += 1) {
state.update(key_block1);
state.update(key_block2);
state.update(kxn1);
state.update(kxn2);
}
return state;
}
fn update(state: *State256, d: AesBlock) callconv(.Inline) void {
const blocks = &state.blocks;
const tmp = blocks[5].encrypt(blocks[0]);
comptime var i: usize = 5;
inline while (i > 0) : (i -= 1) {
blocks[i] = blocks[i - 1].encrypt(blocks[i]);
}
blocks[0] = tmp.xorBlocks(d);
}
fn enc(state: *State256, dst: *[16]u8, src: *const [16]u8) void {
const blocks = &state.blocks;
const msg = AesBlock.fromBytes(src);
var tmp = msg.xorBlocks(blocks[5]).xorBlocks(blocks[4]).xorBlocks(blocks[1]);
tmp = tmp.xorBlocks(blocks[2].andBlocks(blocks[3]));
dst.* = tmp.toBytes();
state.update(msg);
}
fn dec(state: *State256, dst: *[16]u8, src: *const [16]u8) void {
const blocks = &state.blocks;
var msg = AesBlock.fromBytes(src).xorBlocks(blocks[5]).xorBlocks(blocks[4]).xorBlocks(blocks[1]);
msg = msg.xorBlocks(blocks[2].andBlocks(blocks[3]));
dst.* = msg.toBytes();
state.update(msg);
}
fn mac(state: *State256, adlen: usize, mlen: usize) [16]u8 {
const blocks = &state.blocks;
var sizes: [16]u8 = undefined;
mem.writeIntLittle(u64, sizes[0..8], adlen * 8);
mem.writeIntLittle(u64, sizes[8..16], mlen * 8);
const tmp = AesBlock.fromBytes(&sizes).xorBlocks(blocks[3]);
var i: usize = 0;
while (i < 7) : (i += 1) {
state.update(tmp);
}
return blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4])
.xorBlocks(blocks[5]).toBytes();
}
};
/// AEGIS is a very fast authenticated encryption system built on top of the core AES function.
///
/// The 256 bit variant of AEGIS has a 256 bit key, a 256 bit nonce, and processes 128 bit message blocks.
///
/// https://competitions.cr.yp.to/round3/aegisv11.pdf
pub const Aegis256 = struct {
pub const tag_length = 16;
pub const nonce_length = 32;
pub const key_length = 32;
/// c: ciphertext: output buffer should be of size m.len
/// tag: authentication tag: output MAC
/// m: message
/// ad: Associated Data
/// npub: public nonce
/// k: private key
pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) void {
assert(c.len == m.len);
var state = State256.init(key, npub);
var src: [16]u8 align(16) = undefined;
var dst: [16]u8 align(16) = undefined;
var i: usize = 0;
while (i + 16 <= ad.len) : (i += 16) {
state.enc(&dst, ad[i..][0..16]);
}
if (ad.len % 16 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. ad.len % 16], ad[i .. i + ad.len % 16]);
state.enc(&dst, &src);
}
i = 0;
while (i + 16 <= m.len) : (i += 16) {
state.enc(c[i..][0..16], m[i..][0..16]);
}
if (m.len % 16 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. m.len % 16], m[i .. i + m.len % 16]);
state.enc(&dst, &src);
mem.copy(u8, c[i .. i + m.len % 16], dst[0 .. m.len % 16]);
}
tag.* = state.mac(ad.len, m.len);
}
/// m: message: output buffer should be of size c.len
/// c: ciphertext
/// tag: authentication tag
/// ad: Associated Data
/// npub: public nonce
/// k: private key
pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) AuthenticationError!void {
assert(c.len == m.len);
var state = State256.init(key, npub);
var src: [16]u8 align(16) = undefined;
var dst: [16]u8 align(16) = undefined;
var i: usize = 0;
while (i + 16 <= ad.len) : (i += 16) {
state.enc(&dst, ad[i..][0..16]);
}
if (ad.len % 16 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. ad.len % 16], ad[i .. i + ad.len % 16]);
state.enc(&dst, &src);
}
i = 0;
while (i + 16 <= m.len) : (i += 16) {
state.dec(m[i..][0..16], c[i..][0..16]);
}
if (m.len % 16 != 0) {
mem.set(u8, src[0..], 0);
mem.copy(u8, src[0 .. m.len % 16], c[i .. i + m.len % 16]);
state.dec(&dst, &src);
mem.copy(u8, m[i .. i + m.len % 16], dst[0 .. m.len % 16]);
mem.set(u8, dst[0 .. m.len % 16], 0);
const blocks = &state.blocks;
blocks[0] = blocks[0].xorBlocks(AesBlock.fromBytes(&dst));
}
const computed_tag = state.mac(ad.len, m.len);
var acc: u8 = 0;
for (computed_tag) |_, j| {
acc |= (computed_tag[j] ^ tag[j]);
}
if (acc != 0) {
mem.set(u8, m, 0xaa);
return error.AuthenticationFailed;
}
}
};
const htest = @import("test.zig");
const testing = std.testing;
test "Aegis128L test vector 1" {
const key: [Aegis128L.key_length]u8 = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** 14;
const nonce: [Aegis128L.nonce_length]u8 = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** 13;
const ad = [8]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
const m = [32]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f };
var c: [m.len]u8 = undefined;
var m2: [m.len]u8 = undefined;
var tag: [Aegis128L.tag_length]u8 = undefined;
Aegis128L.encrypt(&c, &tag, &m, &ad, nonce, key);
try Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key);
testing.expectEqualSlices(u8, &m, &m2);
htest.assertEqual("79d94593d8c2119d7e8fd9b8fc77845c5c077a05b2528b6ac54b563aed8efe84", &c);
htest.assertEqual("cc6f3372f6aa1bb82388d695c3962d9a", &tag);
c[0] +%= 1;
testing.expectError(error.AuthenticationFailed, Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key));
c[0] -%= 1;
tag[0] +%= 1;
testing.expectError(error.AuthenticationFailed, Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key));
}
test "Aegis128L test vector 2" {
const key: [Aegis128L.key_length]u8 = [_]u8{0x00} ** 16;
const nonce: [Aegis128L.nonce_length]u8 = [_]u8{0x00} ** 16;
const ad = [_]u8{};
const m = [_]u8{0x00} ** 16;
var c: [m.len]u8 = undefined;
var m2: [m.len]u8 = undefined;
var tag: [Aegis128L.tag_length]u8 = undefined;
Aegis128L.encrypt(&c, &tag, &m, &ad, nonce, key);
try Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key);
testing.expectEqualSlices(u8, &m, &m2);
htest.assertEqual("41de9000a7b5e40e2d68bb64d99ebb19", &c);
htest.assertEqual("f4d997cc9b94227ada4fe4165422b1c8", &tag);
}
test "Aegis128L test vector 3" {
const key: [Aegis128L.key_length]u8 = [_]u8{0x00} ** 16;
const nonce: [Aegis128L.nonce_length]u8 = [_]u8{0x00} ** 16;
const ad = [_]u8{};
const m = [_]u8{};
var c: [m.len]u8 = undefined;
var m2: [m.len]u8 = undefined;
var tag: [Aegis128L.tag_length]u8 = undefined;
Aegis128L.encrypt(&c, &tag, &m, &ad, nonce, key);
try Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key);
testing.expectEqualSlices(u8, &m, &m2);
htest.assertEqual("83cc600dc4e3e7e62d4055826174f149", &tag);
}
test "Aegis256 test vector 1" {
const key: [Aegis256.key_length]u8 = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** 30;
const nonce: [Aegis256.nonce_length]u8 = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** 29;
const ad = [8]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
const m = [32]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f };
var c: [m.len]u8 = undefined;
var m2: [m.len]u8 = undefined;
var tag: [Aegis256.tag_length]u8 = undefined;
Aegis256.encrypt(&c, &tag, &m, &ad, nonce, key);
try Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key);
testing.expectEqualSlices(u8, &m, &m2);
htest.assertEqual("f373079ed84b2709faee373584585d60accd191db310ef5d8b11833df9dec711", &c);
htest.assertEqual("8d86f91ee606e9ff26a01b64ccbdd91d", &tag);
c[0] +%= 1;
testing.expectError(error.AuthenticationFailed, Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key));
c[0] -%= 1;
tag[0] +%= 1;
testing.expectError(error.AuthenticationFailed, Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key));
}
test "Aegis256 test vector 2" {
const key: [Aegis256.key_length]u8 = [_]u8{0x00} ** 32;
const nonce: [Aegis256.nonce_length]u8 = [_]u8{0x00} ** 32;
const ad = [_]u8{};
const m = [_]u8{0x00} ** 16;
var c: [m.len]u8 = undefined;
var m2: [m.len]u8 = undefined;
var tag: [Aegis256.tag_length]u8 = undefined;
Aegis256.encrypt(&c, &tag, &m, &ad, nonce, key);
try Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key);
testing.expectEqualSlices(u8, &m, &m2);
htest.assertEqual("b98f03a947807713d75a4fff9fc277a6", &c);
htest.assertEqual("478f3b50dc478ef7d5cf2d0f7cc13180", &tag);
}
test "Aegis256 test vector 3" {
const key: [Aegis256.key_length]u8 = [_]u8{0x00} ** 32;
const nonce: [Aegis256.nonce_length]u8 = [_]u8{0x00} ** 32;
const ad = [_]u8{};
const m = [_]u8{};
var c: [m.len]u8 = undefined;
var m2: [m.len]u8 = undefined;
var tag: [Aegis256.tag_length]u8 = undefined;
Aegis256.encrypt(&c, &tag, &m, &ad, nonce, key);
try Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key);
testing.expectEqualSlices(u8, &m, &m2);
htest.assertEqual("f7a0878f68bd083e8065354071fc27c3", &tag);
}