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   1//! AEGIS is a very fast authenticated encryption system built on top of the core AES function.
   2//!
   3//! The AEGIS-128* variants have a 128 bit key and a 128 bit nonce.
   4//! The AEGIS-256* variants have a 256 bit key and a 256 bit nonce.
   5//! All of them can compute 128 and 256 bit authentication tags.
   6//!
   7//! The AEGIS cipher family offers performance that significantly exceeds that of AES-GCM with
   8//! hardware support for parallelizable AES block encryption.
   9//!
  10//! On high-end Intel CPUs with AVX-512 support, AEGIS-128X4 and AEGIS-256X4 are the fastest options.
  11//! On other modern server, desktop and mobile CPUs, AEGIS-128X2 and AEGIS-256X2 are usually the fastest options.
  12//! AEGIS-128L and AEGIS-256 perform well on a broad range of platforms, including WebAssembly.
  13//!
  14//! Unlike with AES-GCM, nonces can be safely chosen at random with no practical limit when using AEGIS-256*.
  15//! AEGIS-128* also allows for more messages to be safely encrypted when using random nonces.
  16//!
  17//! Unless the associated data can be fully controled by an adversary, AEGIS is believed to be key-committing,
  18//! making it a safer choice than most other AEADs when the key has low entropy, or can be controlled by an attacker.
  19//!
  20//! Finally, leaking the state does not leak the key.
  21//!
  22//! https://datatracker.ietf.org/doc/draft-irtf-cfrg-aegis-aead/
  23
  24const std = @import("std");
  25const crypto = std.crypto;
  26const mem = std.mem;
  27const assert = std.debug.assert;
  28const AuthenticationError = crypto.errors.AuthenticationError;
  29
  30/// AEGIS-128X4 with a 128 bit tag
  31pub const Aegis128X4 = Aegis128XGeneric(4, 128);
  32/// AEGIS-128X2 with a 128 bit tag
  33pub const Aegis128X2 = Aegis128XGeneric(2, 128);
  34/// AEGIS-128L with a 128 bit tag
  35pub const Aegis128L = Aegis128XGeneric(1, 128);
  36
  37/// AEGIS-256X4 with a 128 bit tag
  38pub const Aegis256X4 = Aegis256XGeneric(4, 128);
  39/// AEGIS-256X2 with a 128 bit tag
  40pub const Aegis256X2 = Aegis256XGeneric(2, 128);
  41/// AEGIS-256 with a 128 bit tag
  42pub const Aegis256 = Aegis256XGeneric(1, 128);
  43
  44/// AEGIS-128X4 with a 256 bit tag
  45pub const Aegis128X4_256 = Aegis128XGeneric(4, 256);
  46/// AEGIS-128X2 with a 256 bit tag
  47pub const Aegis128X2_256 = Aegis128XGeneric(2, 256);
  48/// AEGIS-128L with a 256 bit tag
  49pub const Aegis128L_256 = Aegis128XGeneric(1, 256);
  50
  51/// AEGIS-256X4 with a 256 bit tag
  52pub const Aegis256X4_256 = Aegis256XGeneric(4, 256);
  53/// AEGIS-256X2 with a 256 bit tag
  54pub const Aegis256X2_256 = Aegis256XGeneric(2, 256);
  55/// AEGIS-256 with a 256 bit tag
  56pub const Aegis256_256 = Aegis256XGeneric(1, 256);
  57
  58fn State128X(comptime degree: u7) type {
  59    return struct {
  60        const AesBlockVec = crypto.core.aes.BlockVec(degree);
  61        const State = @This();
  62
  63        blocks: [8]AesBlockVec,
  64
  65        const aes_block_length = AesBlockVec.block_length;
  66        const rate = aes_block_length * 2;
  67        const alignment = AesBlockVec.native_word_size;
  68
  69        fn init(key: [16]u8, nonce: [16]u8) State {
  70            const c1 = AesBlockVec.fromBytes(&[16]u8{ 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1, 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd } ** degree);
  71            const c2 = AesBlockVec.fromBytes(&[16]u8{ 0x0, 0x1, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62 } ** degree);
  72            const key_block = AesBlockVec.fromBytes(&(key ** degree));
  73            const nonce_block = AesBlockVec.fromBytes(&(nonce ** degree));
  74            const blocks = [8]AesBlockVec{
  75                key_block.xorBlocks(nonce_block),
  76                c1,
  77                c2,
  78                c1,
  79                key_block.xorBlocks(nonce_block),
  80                key_block.xorBlocks(c2),
  81                key_block.xorBlocks(c1),
  82                key_block.xorBlocks(c2),
  83            };
  84            var state = State{ .blocks = blocks };
  85            if (degree > 1) {
  86                const context_block = ctx: {
  87                    var contexts_bytes = [_]u8{0} ** aes_block_length;
  88                    for (0..degree) |i| {
  89                        contexts_bytes[i * 16] = @intCast(i);
  90                        contexts_bytes[i * 16 + 1] = @intCast(degree - 1);
  91                    }
  92                    break :ctx AesBlockVec.fromBytes(&contexts_bytes);
  93                };
  94                for (0..10) |_| {
  95                    state.blocks[3] = state.blocks[3].xorBlocks(context_block);
  96                    state.blocks[7] = state.blocks[7].xorBlocks(context_block);
  97                    state.update(nonce_block, key_block);
  98                }
  99            } else {
 100                for (0..10) |_| {
 101                    state.update(nonce_block, key_block);
 102                }
 103            }
 104            return state;
 105        }
 106
 107        fn update(state: *State, d1: AesBlockVec, d2: AesBlockVec) void {
 108            const blocks = &state.blocks;
 109            const tmp = blocks[7];
 110            comptime var i: usize = 7;
 111            inline while (i > 0) : (i -= 1) {
 112                blocks[i] = blocks[i - 1].encrypt(blocks[i]);
 113            }
 114            blocks[0] = tmp.encrypt(blocks[0]);
 115            blocks[0] = blocks[0].xorBlocks(d1);
 116            blocks[4] = blocks[4].xorBlocks(d2);
 117        }
 118
 119        fn absorb(state: *State, src: *const [rate]u8) void {
 120            const msg0 = AesBlockVec.fromBytes(src[0..aes_block_length]);
 121            const msg1 = AesBlockVec.fromBytes(src[aes_block_length..rate]);
 122            state.update(msg0, msg1);
 123        }
 124
 125        fn enc(state: *State, dst: *[rate]u8, src: *const [rate]u8) void {
 126            const blocks = &state.blocks;
 127            const msg0 = AesBlockVec.fromBytes(src[0..aes_block_length]);
 128            const msg1 = AesBlockVec.fromBytes(src[aes_block_length..rate]);
 129            var tmp0 = msg0.xorBlocks(blocks[6]).xorBlocks(blocks[1]);
 130            var tmp1 = msg1.xorBlocks(blocks[2]).xorBlocks(blocks[5]);
 131            tmp0 = tmp0.xorBlocks(blocks[2].andBlocks(blocks[3]));
 132            tmp1 = tmp1.xorBlocks(blocks[6].andBlocks(blocks[7]));
 133            dst[0..aes_block_length].* = tmp0.toBytes();
 134            dst[aes_block_length..rate].* = tmp1.toBytes();
 135            state.update(msg0, msg1);
 136        }
 137
 138        fn dec(state: *State, dst: *[rate]u8, src: *const [rate]u8) void {
 139            const blocks = &state.blocks;
 140            var msg0 = AesBlockVec.fromBytes(src[0..aes_block_length]).xorBlocks(blocks[6]).xorBlocks(blocks[1]);
 141            var msg1 = AesBlockVec.fromBytes(src[aes_block_length..rate]).xorBlocks(blocks[2]).xorBlocks(blocks[5]);
 142            msg0 = msg0.xorBlocks(blocks[2].andBlocks(blocks[3]));
 143            msg1 = msg1.xorBlocks(blocks[6].andBlocks(blocks[7]));
 144            dst[0..aes_block_length].* = msg0.toBytes();
 145            dst[aes_block_length..rate].* = msg1.toBytes();
 146            state.update(msg0, msg1);
 147        }
 148
 149        fn decLast(state: *State, dst: []u8, src: []const u8) void {
 150            const blocks = &state.blocks;
 151            const z0 = blocks[6].xorBlocks(blocks[1]).xorBlocks(blocks[2].andBlocks(blocks[3]));
 152            const z1 = blocks[2].xorBlocks(blocks[5]).xorBlocks(blocks[6].andBlocks(blocks[7]));
 153            var pad = [_]u8{0} ** rate;
 154            pad[0..aes_block_length].* = z0.toBytes();
 155            pad[aes_block_length..].* = z1.toBytes();
 156            for (pad[0..src.len], src) |*p, x| p.* ^= x;
 157            @memcpy(dst, pad[0..src.len]);
 158            @memset(pad[src.len..], 0);
 159            const msg0 = AesBlockVec.fromBytes(pad[0..aes_block_length]);
 160            const msg1 = AesBlockVec.fromBytes(pad[aes_block_length..rate]);
 161            state.update(msg0, msg1);
 162        }
 163
 164        fn finalize(state: *State, comptime tag_bits: u9, adlen: usize, mlen: usize) [tag_bits / 8]u8 {
 165            const blocks = &state.blocks;
 166            var sizes: [aes_block_length]u8 = undefined;
 167            mem.writeInt(u64, sizes[0..8], @as(u64, adlen) * 8, .little);
 168            mem.writeInt(u64, sizes[8..16], @as(u64, mlen) * 8, .little);
 169            for (1..degree) |i| {
 170                @memcpy(sizes[i * 16 ..][0..16], sizes[0..16]);
 171            }
 172            const tmp = AesBlockVec.fromBytes(&sizes).xorBlocks(blocks[2]);
 173            for (0..7) |_| {
 174                state.update(tmp, tmp);
 175            }
 176            switch (tag_bits) {
 177                128 => {
 178                    var tag_multi = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).xorBlocks(blocks[5]).xorBlocks(blocks[6]).toBytes();
 179                    var tag = tag_multi[0..16].*;
 180                    @memcpy(tag[0..], tag_multi[0..16]);
 181                    for (1..degree) |d| {
 182                        for (0..16) |i| {
 183                            tag[i] ^= tag_multi[d * 16 + i];
 184                        }
 185                    }
 186                    return tag;
 187                },
 188                256 => {
 189                    const tag_multi_1 = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).toBytes();
 190                    const tag_multi_2 = blocks[4].xorBlocks(blocks[5]).xorBlocks(blocks[6]).xorBlocks(blocks[7]).toBytes();
 191                    var tag = tag_multi_1[0..16].* ++ tag_multi_2[0..16].*;
 192                    for (1..degree) |d| {
 193                        for (0..16) |i| {
 194                            tag[i] ^= tag_multi_1[d * 16 + i];
 195                            tag[i + 16] ^= tag_multi_2[d * 16 + i];
 196                        }
 197                    }
 198                    return tag;
 199                },
 200                else => unreachable,
 201            }
 202        }
 203
 204        fn finalizeMac(state: *State, comptime tag_bits: u9, datalen: usize) [tag_bits / 8]u8 {
 205            const blocks = &state.blocks;
 206            var sizes: [aes_block_length]u8 = undefined;
 207            mem.writeInt(u64, sizes[0..8], @as(u64, datalen) * 8, .little);
 208            mem.writeInt(u64, sizes[8..16], tag_bits, .little);
 209            for (1..degree) |i| {
 210                @memcpy(sizes[i * 16 ..][0..16], sizes[0..16]);
 211            }
 212            var t = blocks[2].xorBlocks(AesBlockVec.fromBytes(&sizes));
 213            for (0..7) |_| {
 214                state.update(t, t);
 215            }
 216            if (degree > 1) {
 217                var v = [_]u8{0} ** rate;
 218                switch (tag_bits) {
 219                    128 => {
 220                        const tags = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).xorBlocks(blocks[5]).xorBlocks(blocks[6]).toBytes();
 221                        for (0..degree / 2) |d| {
 222                            v[0..16].* = tags[d * 32 ..][0..16].*;
 223                            v[rate / 2 ..][0..16].* = tags[d * 32 ..][16..32].*;
 224                            state.absorb(&v);
 225                        }
 226                    },
 227                    256 => {
 228                        const tags_0 = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).toBytes();
 229                        const tags_1 = blocks[4].xorBlocks(blocks[5]).xorBlocks(blocks[6]).xorBlocks(blocks[7]).toBytes();
 230                        for (1..degree) |d| {
 231                            v[0..16].* = tags_0[d * 16 ..][0..16].*;
 232                            v[rate / 2 ..][0..16].* = tags_1[d * 16 ..][0..16].*;
 233                            state.absorb(&v);
 234                        }
 235                    },
 236                    else => unreachable,
 237                }
 238                mem.writeInt(u64, sizes[0..8], degree, .little);
 239                mem.writeInt(u64, sizes[8..16], tag_bits, .little);
 240                t = blocks[2].xorBlocks(AesBlockVec.fromBytes(&sizes));
 241                for (0..7) |_| {
 242                    state.update(t, t);
 243                }
 244            }
 245            switch (tag_bits) {
 246                128 => {
 247                    const tags = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).xorBlocks(blocks[5]).xorBlocks(blocks[6]).toBytes();
 248                    return tags[0..16].*;
 249                },
 250                256 => {
 251                    const tags_0 = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).toBytes();
 252                    const tags_1 = blocks[4].xorBlocks(blocks[5]).xorBlocks(blocks[6]).xorBlocks(blocks[7]).toBytes();
 253                    return tags_0[0..16].* ++ tags_1[0..16].*;
 254                },
 255                else => unreachable,
 256            }
 257        }
 258    };
 259}
 260
 261/// AEGIS is a very fast authenticated encryption system built on top of the core AES function.
 262///
 263/// The 128 bits variants of AEGIS have a 128 bit key and a 128 bit nonce.
 264///
 265/// https://datatracker.ietf.org/doc/draft-irtf-cfrg-aegis-aead/
 266fn Aegis128XGeneric(comptime degree: u7, comptime tag_bits: u9) type {
 267    comptime assert(degree > 0); // degree must be greater than 0
 268    comptime assert(tag_bits == 128 or tag_bits == 256); // tag must be 128 or 256 bits
 269
 270    return struct {
 271        const State = State128X(degree);
 272
 273        pub const tag_length = tag_bits / 8;
 274        pub const nonce_length = 16;
 275        pub const key_length = 16;
 276        pub const block_length = State.rate;
 277
 278        const alignment = State.alignment;
 279
 280        /// c: ciphertext: output buffer should be of size m.len
 281        /// tag: authentication tag: output MAC
 282        /// m: message
 283        /// ad: Associated Data
 284        /// npub: public nonce
 285        /// k: private key
 286        pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) void {
 287            assert(c.len == m.len);
 288            var state = State.init(key, npub);
 289            var src: [block_length]u8 align(alignment) = undefined;
 290            var dst: [block_length]u8 align(alignment) = undefined;
 291            var i: usize = 0;
 292            while (i + block_length <= ad.len) : (i += block_length) {
 293                state.absorb(ad[i..][0..block_length]);
 294            }
 295            if (ad.len % block_length != 0) {
 296                @memset(src[0..], 0);
 297                @memcpy(src[0 .. ad.len % block_length], ad[i..][0 .. ad.len % block_length]);
 298                state.absorb(&src);
 299            }
 300            i = 0;
 301            while (i + block_length <= m.len) : (i += block_length) {
 302                state.enc(c[i..][0..block_length], m[i..][0..block_length]);
 303            }
 304            if (m.len % block_length != 0) {
 305                @memset(src[0..], 0);
 306                @memcpy(src[0 .. m.len % block_length], m[i..][0 .. m.len % block_length]);
 307                state.enc(&dst, &src);
 308                @memcpy(c[i..][0 .. m.len % block_length], dst[0 .. m.len % block_length]);
 309            }
 310            tag.* = state.finalize(tag_bits, ad.len, m.len);
 311        }
 312
 313        /// `m`: Message
 314        /// `c`: Ciphertext
 315        /// `tag`: Authentication tag
 316        /// `ad`: Associated data
 317        /// `npub`: Public nonce
 318        /// `k`: Private key
 319        /// Asserts `c.len == m.len`.
 320        ///
 321        /// Contents of `m` are undefined if an error is returned.
 322        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 {
 323            assert(c.len == m.len);
 324            var state = State.init(key, npub);
 325            var src: [block_length]u8 align(alignment) = undefined;
 326            var i: usize = 0;
 327            while (i + block_length <= ad.len) : (i += block_length) {
 328                state.absorb(ad[i..][0..block_length]);
 329            }
 330            if (ad.len % block_length != 0) {
 331                @memset(src[0..], 0);
 332                @memcpy(src[0 .. ad.len % block_length], ad[i..][0 .. ad.len % block_length]);
 333                state.absorb(&src);
 334            }
 335            i = 0;
 336            while (i + block_length <= m.len) : (i += block_length) {
 337                state.dec(m[i..][0..block_length], c[i..][0..block_length]);
 338            }
 339            if (m.len % block_length != 0) {
 340                state.decLast(m[i..], c[i..]);
 341            }
 342            var computed_tag = state.finalize(tag_bits, ad.len, m.len);
 343            const verify = crypto.timing_safe.eql([tag_length]u8, computed_tag, tag);
 344            if (!verify) {
 345                crypto.secureZero(u8, &computed_tag);
 346                @memset(m, undefined);
 347                return error.AuthenticationFailed;
 348            }
 349        }
 350    };
 351}
 352
 353fn State256X(comptime degree: u7) type {
 354    return struct {
 355        const AesBlockVec = crypto.core.aes.BlockVec(degree);
 356        const State = @This();
 357
 358        blocks: [6]AesBlockVec,
 359
 360        const aes_block_length = AesBlockVec.block_length;
 361        const rate = aes_block_length;
 362        const alignment = AesBlockVec.native_word_size;
 363
 364        fn init(key: [32]u8, nonce: [32]u8) State {
 365            const c1 = AesBlockVec.fromBytes(&[16]u8{ 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1, 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd } ** degree);
 366            const c2 = AesBlockVec.fromBytes(&[16]u8{ 0x0, 0x1, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62 } ** degree);
 367            const key_block1 = AesBlockVec.fromBytes(key[0..16] ** degree);
 368            const key_block2 = AesBlockVec.fromBytes(key[16..32] ** degree);
 369            const nonce_block1 = AesBlockVec.fromBytes(nonce[0..16] ** degree);
 370            const nonce_block2 = AesBlockVec.fromBytes(nonce[16..32] ** degree);
 371            const kxn1 = key_block1.xorBlocks(nonce_block1);
 372            const kxn2 = key_block2.xorBlocks(nonce_block2);
 373            const blocks = [6]AesBlockVec{
 374                kxn1,
 375                kxn2,
 376                c1,
 377                c2,
 378                key_block1.xorBlocks(c2),
 379                key_block2.xorBlocks(c1),
 380            };
 381            var state = State{ .blocks = blocks };
 382            if (degree > 1) {
 383                const context_block = ctx: {
 384                    var contexts_bytes = [_]u8{0} ** aes_block_length;
 385                    for (0..degree) |i| {
 386                        contexts_bytes[i * 16] = @intCast(i);
 387                        contexts_bytes[i * 16 + 1] = @intCast(degree - 1);
 388                    }
 389                    break :ctx AesBlockVec.fromBytes(&contexts_bytes);
 390                };
 391                for (0..4) |_| {
 392                    state.blocks[3] = state.blocks[3].xorBlocks(context_block);
 393                    state.blocks[5] = state.blocks[5].xorBlocks(context_block);
 394                    state.update(key_block1);
 395                    state.blocks[3] = state.blocks[3].xorBlocks(context_block);
 396                    state.blocks[5] = state.blocks[5].xorBlocks(context_block);
 397                    state.update(key_block2);
 398                    state.blocks[3] = state.blocks[3].xorBlocks(context_block);
 399                    state.blocks[5] = state.blocks[5].xorBlocks(context_block);
 400                    state.update(kxn1);
 401                    state.blocks[3] = state.blocks[3].xorBlocks(context_block);
 402                    state.blocks[5] = state.blocks[5].xorBlocks(context_block);
 403                    state.update(kxn2);
 404                }
 405            } else {
 406                for (0..4) |_| {
 407                    state.update(key_block1);
 408                    state.update(key_block2);
 409                    state.update(kxn1);
 410                    state.update(kxn2);
 411                }
 412            }
 413            return state;
 414        }
 415
 416        fn update(state: *State, d: AesBlockVec) void {
 417            const blocks = &state.blocks;
 418            const tmp = blocks[5].encrypt(blocks[0]);
 419            comptime var i: usize = 5;
 420            inline while (i > 0) : (i -= 1) {
 421                blocks[i] = blocks[i - 1].encrypt(blocks[i]);
 422            }
 423            blocks[0] = tmp.xorBlocks(d);
 424        }
 425
 426        fn absorb(state: *State, src: *const [rate]u8) void {
 427            const msg = AesBlockVec.fromBytes(src);
 428            state.update(msg);
 429        }
 430
 431        fn enc(state: *State, dst: *[rate]u8, src: *const [rate]u8) void {
 432            const blocks = &state.blocks;
 433            const msg = AesBlockVec.fromBytes(src);
 434            var tmp = msg.xorBlocks(blocks[5]).xorBlocks(blocks[4]).xorBlocks(blocks[1]);
 435            tmp = tmp.xorBlocks(blocks[2].andBlocks(blocks[3]));
 436            dst.* = tmp.toBytes();
 437            state.update(msg);
 438        }
 439
 440        fn dec(state: *State, dst: *[rate]u8, src: *const [rate]u8) void {
 441            const blocks = &state.blocks;
 442            var msg = AesBlockVec.fromBytes(src).xorBlocks(blocks[5]).xorBlocks(blocks[4]).xorBlocks(blocks[1]);
 443            msg = msg.xorBlocks(blocks[2].andBlocks(blocks[3]));
 444            dst.* = msg.toBytes();
 445            state.update(msg);
 446        }
 447
 448        fn decLast(state: *State, dst: []u8, src: []const u8) void {
 449            const blocks = &state.blocks;
 450            const z = blocks[5].xorBlocks(blocks[4]).xorBlocks(blocks[1]).xorBlocks(blocks[2].andBlocks(blocks[3]));
 451            var pad = z.toBytes();
 452            for (pad[0..src.len], src) |*p, x| p.* ^= x;
 453            @memcpy(dst, pad[0..src.len]);
 454            @memset(pad[src.len..], 0);
 455            const msg = AesBlockVec.fromBytes(pad[0..]);
 456            state.update(msg);
 457        }
 458
 459        fn finalize(state: *State, comptime tag_bits: u9, adlen: usize, mlen: usize) [tag_bits / 8]u8 {
 460            const blocks = &state.blocks;
 461            var sizes: [aes_block_length]u8 = undefined;
 462            mem.writeInt(u64, sizes[0..8], @as(u64, adlen) * 8, .little);
 463            mem.writeInt(u64, sizes[8..16], @as(u64, mlen) * 8, .little);
 464            for (1..degree) |i| {
 465                @memcpy(sizes[i * 16 ..][0..16], sizes[0..16]);
 466            }
 467            const tmp = AesBlockVec.fromBytes(&sizes).xorBlocks(blocks[3]);
 468            for (0..7) |_| {
 469                state.update(tmp);
 470            }
 471            switch (tag_bits) {
 472                128 => {
 473                    var tag_multi = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).xorBlocks(blocks[5]).toBytes();
 474                    var tag = tag_multi[0..16].*;
 475                    @memcpy(tag[0..], tag_multi[0..16]);
 476                    for (1..degree) |d| {
 477                        for (0..16) |i| {
 478                            tag[i] ^= tag_multi[d * 16 + i];
 479                        }
 480                    }
 481                    return tag;
 482                },
 483                256 => {
 484                    const tag_multi_1 = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).toBytes();
 485                    const tag_multi_2 = blocks[3].xorBlocks(blocks[4]).xorBlocks(blocks[5]).toBytes();
 486                    var tag = tag_multi_1[0..16].* ++ tag_multi_2[0..16].*;
 487                    for (1..degree) |d| {
 488                        for (0..16) |i| {
 489                            tag[i] ^= tag_multi_1[d * 16 + i];
 490                            tag[i + 16] ^= tag_multi_2[d * 16 + i];
 491                        }
 492                    }
 493                    return tag;
 494                },
 495                else => unreachable,
 496            }
 497        }
 498
 499        fn finalizeMac(state: *State, comptime tag_bits: u9, datalen: usize) [tag_bits / 8]u8 {
 500            const blocks = &state.blocks;
 501            var sizes: [aes_block_length]u8 = undefined;
 502            mem.writeInt(u64, sizes[0..8], @as(u64, datalen) * 8, .little);
 503            mem.writeInt(u64, sizes[8..16], tag_bits, .little);
 504            for (1..degree) |i| {
 505                @memcpy(sizes[i * 16 ..][0..16], sizes[0..16]);
 506            }
 507            var t = blocks[3].xorBlocks(AesBlockVec.fromBytes(&sizes));
 508            for (0..7) |_| {
 509                state.update(t);
 510            }
 511            if (degree > 1) {
 512                var v = [_]u8{0} ** rate;
 513                switch (tag_bits) {
 514                    128 => {
 515                        const tags = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).xorBlocks(blocks[5]).toBytes();
 516                        for (1..degree) |d| {
 517                            v[0..16].* = tags[d * 16 ..][0..16].*;
 518                            state.absorb(&v);
 519                        }
 520                    },
 521                    256 => {
 522                        const tags_0 = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).toBytes();
 523                        const tags_1 = blocks[3].xorBlocks(blocks[4]).xorBlocks(blocks[5]).toBytes();
 524                        for (1..degree) |d| {
 525                            v[0..16].* = tags_0[d * 16 ..][0..16].*;
 526                            state.absorb(&v);
 527                            v[0..16].* = tags_1[d * 16 ..][0..16].*;
 528                            state.absorb(&v);
 529                        }
 530                    },
 531                    else => unreachable,
 532                }
 533                mem.writeInt(u64, sizes[0..8], degree, .little);
 534                mem.writeInt(u64, sizes[8..16], tag_bits, .little);
 535                t = blocks[3].xorBlocks(AesBlockVec.fromBytes(&sizes));
 536                for (0..7) |_| {
 537                    state.update(t);
 538                }
 539            }
 540            switch (tag_bits) {
 541                128 => {
 542                    const tags = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).xorBlocks(blocks[5]).toBytes();
 543                    return tags[0..16].*;
 544                },
 545                256 => {
 546                    const tags_0 = blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).toBytes();
 547                    const tags_1 = blocks[3].xorBlocks(blocks[4]).xorBlocks(blocks[5]).toBytes();
 548                    return tags_0[0..16].* ++ tags_1[0..16].*;
 549                },
 550                else => unreachable,
 551            }
 552        }
 553    };
 554}
 555
 556/// AEGIS is a very fast authenticated encryption system built on top of the core AES function.
 557///
 558/// The 256 bits variants of AEGIS have a 256 bit key and a 256 bit nonce.
 559///
 560/// https://datatracker.ietf.org/doc/draft-irtf-cfrg-aegis-aead/
 561fn Aegis256XGeneric(comptime degree: u7, comptime tag_bits: u9) type {
 562    comptime assert(degree > 0); // degree must be greater than 0
 563    comptime assert(tag_bits == 128 or tag_bits == 256); // tag must be 128 or 256 bits
 564
 565    return struct {
 566        const State = State256X(degree);
 567
 568        pub const tag_length = tag_bits / 8;
 569        pub const nonce_length = 32;
 570        pub const key_length = 32;
 571        pub const block_length = State.rate;
 572
 573        const alignment = State.alignment;
 574
 575        /// c: ciphertext: output buffer should be of size m.len
 576        /// tag: authentication tag: output MAC
 577        /// m: message
 578        /// ad: Associated Data
 579        /// npub: public nonce
 580        /// k: private key
 581        pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) void {
 582            assert(c.len == m.len);
 583            var state = State.init(key, npub);
 584            var src: [block_length]u8 align(alignment) = undefined;
 585            var dst: [block_length]u8 align(alignment) = undefined;
 586            var i: usize = 0;
 587            while (i + block_length <= ad.len) : (i += block_length) {
 588                state.absorb(ad[i..][0..block_length]);
 589            }
 590            if (ad.len % block_length != 0) {
 591                @memset(src[0..], 0);
 592                @memcpy(src[0 .. ad.len % block_length], ad[i..][0 .. ad.len % block_length]);
 593                state.absorb(&src);
 594            }
 595            i = 0;
 596            while (i + block_length <= m.len) : (i += block_length) {
 597                state.enc(c[i..][0..block_length], m[i..][0..block_length]);
 598            }
 599            if (m.len % block_length != 0) {
 600                @memset(src[0..], 0);
 601                @memcpy(src[0 .. m.len % block_length], m[i..][0 .. m.len % block_length]);
 602                state.enc(&dst, &src);
 603                @memcpy(c[i..][0 .. m.len % block_length], dst[0 .. m.len % block_length]);
 604            }
 605            tag.* = state.finalize(tag_bits, ad.len, m.len);
 606        }
 607
 608        /// `m`: Message
 609        /// `c`: Ciphertext
 610        /// `tag`: Authentication tag
 611        /// `ad`: Associated data
 612        /// `npub`: Public nonce
 613        /// `k`: Private key
 614        /// Asserts `c.len == m.len`.
 615        ///
 616        /// Contents of `m` are undefined if an error is returned.
 617        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 {
 618            assert(c.len == m.len);
 619            var state = State.init(key, npub);
 620            var src: [block_length]u8 align(alignment) = undefined;
 621            var i: usize = 0;
 622            while (i + block_length <= ad.len) : (i += block_length) {
 623                state.absorb(ad[i..][0..block_length]);
 624            }
 625            if (ad.len % block_length != 0) {
 626                @memset(src[0..], 0);
 627                @memcpy(src[0 .. ad.len % block_length], ad[i..][0 .. ad.len % block_length]);
 628                state.absorb(&src);
 629            }
 630            i = 0;
 631            while (i + block_length <= m.len) : (i += block_length) {
 632                state.dec(m[i..][0..block_length], c[i..][0..block_length]);
 633            }
 634            if (m.len % block_length != 0) {
 635                state.decLast(m[i..], c[i..]);
 636            }
 637            var computed_tag = state.finalize(tag_bits, ad.len, m.len);
 638            const verify = crypto.timing_safe.eql([tag_length]u8, computed_tag, tag);
 639            if (!verify) {
 640                crypto.secureZero(u8, &computed_tag);
 641                @memset(m, undefined);
 642                return error.AuthenticationFailed;
 643            }
 644        }
 645    };
 646}
 647
 648/// The `Aegis128X4Mac` message authentication function outputs 256 bit tags.
 649/// In addition to being extremely fast, its large state, non-linearity
 650/// and non-invertibility provides the following properties:
 651/// - 128 bit security, stronger than GHash/Polyval/Poly1305.
 652/// - Recovering the secret key from the state would require ~2^128 attempts,
 653///   which is infeasible for any practical adversary.
 654/// - It has a large security margin against internal collisions.
 655pub const Aegis128X4Mac = AegisMac(Aegis128X4_256);
 656
 657/// The `Aegis128X2Mac` message authentication function outputs 256 bit tags.
 658/// In addition to being extremely fast, its large state, non-linearity
 659/// and non-invertibility provides the following properties:
 660/// - 128 bit security, stronger than GHash/Polyval/Poly1305.
 661/// - Recovering the secret key from the state would require ~2^128 attempts,
 662///   which is infeasible for any practical adversary.
 663/// - It has a large security margin against internal collisions.
 664pub const Aegis128X2Mac = AegisMac(Aegis128X2_256);
 665
 666/// The `Aegis128LMac` message authentication function outputs 256 bit tags.
 667/// In addition to being extremely fast, its large state, non-linearity
 668/// and non-invertibility provides the following properties:
 669/// - 128 bit security, stronger than GHash/Polyval/Poly1305.
 670/// - Recovering the secret key from the state would require ~2^128 attempts,
 671///   which is infeasible for any practical adversary.
 672/// - It has a large security margin against internal collisions.
 673pub const Aegis128LMac = AegisMac(Aegis128L_256);
 674
 675/// The `Aegis256X4Mac` message authentication function has a 256-bit key size,
 676/// and outputs 256 bit tags.
 677/// The key size is the main practical difference with `Aegis128X4Mac`.
 678/// AEGIS' large state, non-linearity and non-invertibility provides the
 679/// following properties:
 680/// - 256 bit security against forgery.
 681/// - Recovering the secret key from the state would require ~2^256 attempts,
 682///   which is infeasible for any practical adversary.
 683/// - It has a large security margin against internal collisions.
 684pub const Aegis256X4Mac = AegisMac(Aegis256X4_256);
 685
 686/// The `Aegis256X2Mac` message authentication function has a 256-bit key size,
 687/// and outputs 256 bit tags.
 688/// The key size is the main practical difference with `Aegis128X2Mac`.
 689/// AEGIS' large state, non-linearity and non-invertibility provides the
 690/// following properties:
 691/// - 256 bit security against forgery.
 692/// - Recovering the secret key from the state would require ~2^256 attempts,
 693///   which is infeasible for any practical adversary.
 694/// - It has a large security margin against internal collisions.
 695pub const Aegis256X2Mac = AegisMac(Aegis256X2_256);
 696
 697/// The `Aegis256Mac` message authentication function has a 256-bit key size,
 698/// and outputs 256 bit tags.
 699/// The key size is the main practical difference with `Aegis128LMac`.
 700/// AEGIS' large state, non-linearity and non-invertibility provides the
 701/// following properties:
 702/// - 256 bit security against forgery.
 703/// - Recovering the secret key from the state would require ~2^256 attempts,
 704///   which is infeasible for any practical adversary.
 705/// - It has a large security margin against internal collisions.
 706pub const Aegis256Mac = AegisMac(Aegis256_256);
 707
 708/// AEGIS-128X4 MAC with 128-bit tags
 709pub const Aegis128X4Mac_128 = AegisMac(Aegis128X4);
 710
 711/// AEGIS-128X2 MAC with 128-bit tags
 712pub const Aegis128X2Mac_128 = AegisMac(Aegis128X2);
 713
 714/// AEGIS-128L MAC with 128-bit tags
 715pub const Aegis128LMac_128 = AegisMac(Aegis128L);
 716
 717/// AEGIS-256X4 MAC with 128-bit tags
 718pub const Aegis256X4Mac_128 = AegisMac(Aegis256X4);
 719
 720/// AEGIS-256X2 MAC with 128-bit tags
 721pub const Aegis256X2Mac_128 = AegisMac(Aegis256X2);
 722
 723/// AEGIS-256 MAC with 128-bit tags
 724pub const Aegis256Mac_128 = AegisMac(Aegis256);
 725
 726fn AegisMac(comptime T: type) type {
 727    return struct {
 728        const Mac = @This();
 729
 730        pub const mac_length = T.tag_length;
 731        pub const key_length = T.key_length;
 732        pub const nonce_length = T.nonce_length;
 733        pub const block_length = T.block_length;
 734
 735        state: T.State,
 736        buf: [block_length]u8 = undefined,
 737        off: usize = 0,
 738        msg_len: usize = 0,
 739
 740        /// Initialize a state for the MAC function, with a key and a nonce
 741        pub fn initWithNonce(key: *const [key_length]u8, nonce: *const [nonce_length]u8) Mac {
 742            return Mac{
 743                .state = T.State.init(key.*, nonce.*),
 744            };
 745        }
 746
 747        /// Initialize a state for the MAC function, with a default nonce
 748        pub fn init(key: *const [key_length]u8) Mac {
 749            return Mac{
 750                .state = T.State.init(key.*, [_]u8{0} ** nonce_length),
 751            };
 752        }
 753
 754        /// Add data to the state
 755        pub fn update(self: *Mac, b: []const u8) void {
 756            self.msg_len += b.len;
 757
 758            const len_partial = @min(b.len, block_length - self.off);
 759            @memcpy(self.buf[self.off..][0..len_partial], b[0..len_partial]);
 760            self.off += len_partial;
 761            if (self.off < block_length) {
 762                return;
 763            }
 764            self.state.absorb(&self.buf);
 765
 766            var i = len_partial;
 767            self.off = 0;
 768            while (i + block_length * 2 <= b.len) : (i += block_length * 2) {
 769                self.state.absorb(b[i..][0..block_length]);
 770                self.state.absorb(b[i..][block_length .. block_length * 2]);
 771            }
 772            while (i + block_length <= b.len) : (i += block_length) {
 773                self.state.absorb(b[i..][0..block_length]);
 774            }
 775            if (i != b.len) {
 776                self.off = b.len - i;
 777                @memcpy(self.buf[0..self.off], b[i..]);
 778            }
 779        }
 780
 781        /// Return an authentication tag for the current state
 782        pub fn final(self: *Mac, out: *[mac_length]u8) void {
 783            if (self.off > 0) {
 784                var pad = [_]u8{0} ** block_length;
 785                @memcpy(pad[0..self.off], self.buf[0..self.off]);
 786                self.state.absorb(&pad);
 787            }
 788            out.* = self.state.finalizeMac(T.tag_length * 8, self.msg_len);
 789        }
 790
 791        /// Return an authentication tag for a message, a key and a nonce
 792        pub fn createWithNonce(out: *[mac_length]u8, msg: []const u8, key: *const [key_length]u8, nonce: *const [nonce_length]u8) void {
 793            var ctx = Mac.initWithNonce(key, nonce);
 794            ctx.update(msg);
 795            ctx.final(out);
 796        }
 797
 798        /// Return an authentication tag for a message and a key
 799        pub fn create(out: *[mac_length]u8, msg: []const u8, key: *const [key_length]u8) void {
 800            var ctx = Mac.init(key);
 801            ctx.update(msg);
 802            ctx.final(out);
 803        }
 804    };
 805}
 806
 807const htest = @import("test.zig");
 808const testing = std.testing;
 809
 810test "Aegis128L test vector 1" {
 811    const key: [Aegis128L.key_length]u8 = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** 14;
 812    const nonce: [Aegis128L.nonce_length]u8 = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** 13;
 813    const ad = [8]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
 814    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 };
 815    var c: [m.len]u8 = undefined;
 816    var m2: [m.len]u8 = undefined;
 817    var tag: [Aegis128L.tag_length]u8 = undefined;
 818
 819    Aegis128L.encrypt(&c, &tag, &m, &ad, nonce, key);
 820    try Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key);
 821    try testing.expectEqualSlices(u8, &m, &m2);
 822
 823    try htest.assertEqual("79d94593d8c2119d7e8fd9b8fc77845c5c077a05b2528b6ac54b563aed8efe84", &c);
 824    try htest.assertEqual("cc6f3372f6aa1bb82388d695c3962d9a", &tag);
 825
 826    c[0] +%= 1;
 827    try testing.expectError(error.AuthenticationFailed, Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key));
 828    c[0] -%= 1;
 829    tag[0] +%= 1;
 830    try testing.expectError(error.AuthenticationFailed, Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key));
 831}
 832
 833test "Aegis128L test vector 2" {
 834    const key: [Aegis128L.key_length]u8 = [_]u8{0x00} ** 16;
 835    const nonce: [Aegis128L.nonce_length]u8 = [_]u8{0x00} ** 16;
 836    const ad = [_]u8{};
 837    const m = [_]u8{0x00} ** 16;
 838    var c: [m.len]u8 = undefined;
 839    var m2: [m.len]u8 = undefined;
 840    var tag: [Aegis128L.tag_length]u8 = undefined;
 841
 842    Aegis128L.encrypt(&c, &tag, &m, &ad, nonce, key);
 843    try Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key);
 844    try testing.expectEqualSlices(u8, &m, &m2);
 845
 846    try htest.assertEqual("41de9000a7b5e40e2d68bb64d99ebb19", &c);
 847    try htest.assertEqual("f4d997cc9b94227ada4fe4165422b1c8", &tag);
 848}
 849
 850test "Aegis128L test vector 3" {
 851    const key: [Aegis128L.key_length]u8 = [_]u8{0x00} ** 16;
 852    const nonce: [Aegis128L.nonce_length]u8 = [_]u8{0x00} ** 16;
 853    const ad = [_]u8{};
 854    const m = [_]u8{};
 855    var c: [m.len]u8 = undefined;
 856    var m2: [m.len]u8 = undefined;
 857    var tag: [Aegis128L.tag_length]u8 = undefined;
 858
 859    Aegis128L.encrypt(&c, &tag, &m, &ad, nonce, key);
 860    try Aegis128L.decrypt(&m2, &c, tag, &ad, nonce, key);
 861    try testing.expectEqualSlices(u8, &m, &m2);
 862
 863    try htest.assertEqual("83cc600dc4e3e7e62d4055826174f149", &tag);
 864}
 865
 866test "Aegis128X2 test vector 1" {
 867    const key: [Aegis128X2.key_length]u8 = [_]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
 868    const nonce: [Aegis128X2.nonce_length]u8 = [_]u8{ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f };
 869    var empty = [_]u8{};
 870    var tag: [Aegis128X2.tag_length]u8 = undefined;
 871    var tag256: [Aegis128X2_256.tag_length]u8 = undefined;
 872
 873    Aegis128X2.encrypt(&empty, &tag, &empty, &empty, nonce, key);
 874    Aegis128X2_256.encrypt(&empty, &tag256, &empty, &empty, nonce, key);
 875    try htest.assertEqual("63117dc57756e402819a82e13eca8379", &tag);
 876    try htest.assertEqual("b92c71fdbd358b8a4de70b27631ace90cffd9b9cfba82028412bac41b4f53759", &tag256);
 877    tag[0] +%= 1;
 878    try testing.expectError(error.AuthenticationFailed, Aegis128X2.decrypt(&empty, &empty, tag, &empty, nonce, key));
 879    tag256[0] +%= 1;
 880    try testing.expectError(error.AuthenticationFailed, Aegis128X2_256.decrypt(&empty, &empty, tag256, &empty, nonce, key));
 881}
 882
 883test "Aegis256 test vector 1" {
 884    const key: [Aegis256.key_length]u8 = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** 30;
 885    const nonce: [Aegis256.nonce_length]u8 = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** 29;
 886    const ad = [8]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
 887    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 };
 888    var c: [m.len]u8 = undefined;
 889    var m2: [m.len]u8 = undefined;
 890    var tag: [Aegis256.tag_length]u8 = undefined;
 891
 892    Aegis256.encrypt(&c, &tag, &m, &ad, nonce, key);
 893    try Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key);
 894    try testing.expectEqualSlices(u8, &m, &m2);
 895
 896    try htest.assertEqual("f373079ed84b2709faee373584585d60accd191db310ef5d8b11833df9dec711", &c);
 897    try htest.assertEqual("8d86f91ee606e9ff26a01b64ccbdd91d", &tag);
 898
 899    c[0] +%= 1;
 900    try testing.expectError(error.AuthenticationFailed, Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key));
 901    c[0] -%= 1;
 902    tag[0] +%= 1;
 903    try testing.expectError(error.AuthenticationFailed, Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key));
 904}
 905
 906test "Aegis256 test vector 2" {
 907    const key: [Aegis256.key_length]u8 = [_]u8{0x00} ** 32;
 908    const nonce: [Aegis256.nonce_length]u8 = [_]u8{0x00} ** 32;
 909    const ad = [_]u8{};
 910    const m = [_]u8{0x00} ** 16;
 911    var c: [m.len]u8 = undefined;
 912    var m2: [m.len]u8 = undefined;
 913    var tag: [Aegis256.tag_length]u8 = undefined;
 914
 915    Aegis256.encrypt(&c, &tag, &m, &ad, nonce, key);
 916    try Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key);
 917    try testing.expectEqualSlices(u8, &m, &m2);
 918
 919    try htest.assertEqual("b98f03a947807713d75a4fff9fc277a6", &c);
 920    try htest.assertEqual("478f3b50dc478ef7d5cf2d0f7cc13180", &tag);
 921}
 922
 923test "Aegis256 test vector 3" {
 924    const key: [Aegis256.key_length]u8 = [_]u8{0x00} ** 32;
 925    const nonce: [Aegis256.nonce_length]u8 = [_]u8{0x00} ** 32;
 926    const ad = [_]u8{};
 927    const m = [_]u8{};
 928    var c: [m.len]u8 = undefined;
 929    var m2: [m.len]u8 = undefined;
 930    var tag: [Aegis256.tag_length]u8 = undefined;
 931
 932    Aegis256.encrypt(&c, &tag, &m, &ad, nonce, key);
 933    try Aegis256.decrypt(&m2, &c, tag, &ad, nonce, key);
 934    try testing.expectEqualSlices(u8, &m, &m2);
 935
 936    try htest.assertEqual("f7a0878f68bd083e8065354071fc27c3", &tag);
 937}
 938
 939test "Aegis256X4 test vector 1" {
 940    const key: [Aegis256X4.key_length]u8 = [_]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 };
 941    const nonce: [Aegis256X4.nonce_length]u8 = [_]u8{ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f };
 942    var empty = [_]u8{};
 943    var tag: [Aegis256X4.tag_length]u8 = undefined;
 944    var tag256: [Aegis256X4_256.tag_length]u8 = undefined;
 945
 946    Aegis256X4.encrypt(&empty, &tag, &empty, &empty, nonce, key);
 947    Aegis256X4_256.encrypt(&empty, &tag256, &empty, &empty, nonce, key);
 948    try htest.assertEqual("3b7fee6cee7bf17888ad11ed2397beb4", &tag);
 949    try htest.assertEqual("6093a1a8aab20ec635dc1ca71745b01b5bec4fc444c9ffbebd710d4a34d20eaf", &tag256);
 950    tag[0] +%= 1;
 951    try testing.expectError(error.AuthenticationFailed, Aegis256X4.decrypt(&empty, &empty, tag, &empty, nonce, key));
 952    tag256[0] +%= 1;
 953    try testing.expectError(error.AuthenticationFailed, Aegis256X4_256.decrypt(&empty, &empty, tag256, &empty, nonce, key));
 954}
 955
 956test "Aegis MAC" {
 957    const key = [_]u8{0x00} ** Aegis128LMac.key_length;
 958    var msg: [64]u8 = undefined;
 959    for (&msg, 0..) |*m, i| {
 960        m.* = @as(u8, @truncate(i));
 961    }
 962    const st_init = Aegis128LMac.init(&key);
 963    var st = st_init;
 964    var tag: [Aegis128LMac.mac_length]u8 = undefined;
 965
 966    st.update(msg[0..32]);
 967    st.update(msg[32..]);
 968    st.final(&tag);
 969    try htest.assertEqual("f5eb88d90b7d31c9a679eb94ed1374cd14816b19cdb77930d1a5158f8595983b", &tag);
 970
 971    st = st_init;
 972    st.update(msg[0..31]);
 973    st.update(msg[31..]);
 974    st.final(&tag);
 975    try htest.assertEqual("f5eb88d90b7d31c9a679eb94ed1374cd14816b19cdb77930d1a5158f8595983b", &tag);
 976
 977    st = st_init;
 978    st.update(msg[0..14]);
 979    st.update(msg[14..30]);
 980    st.update(msg[30..]);
 981    st.final(&tag);
 982    try htest.assertEqual("f5eb88d90b7d31c9a679eb94ed1374cd14816b19cdb77930d1a5158f8595983b", &tag);
 983
 984    // An update whose size is not a multiple of the block size
 985    st = st_init;
 986    st.update(msg[0..33]);
 987    st.final(&tag);
 988    try htest.assertEqual("07b3ba5ad9ceee5ef1906e3396f0fa540fbcd2f33833ef97c35bdc2ae9ae0535", &tag);
 989}
 990
 991test "AEGISMAC-128* test vectors" {
 992    const key = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** (16 - 2);
 993    const nonce = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** (16 - 3);
 994    var msg: [35]u8 = undefined;
 995    for (&msg, 0..) |*byte, i| byte.* = @truncate(i);
 996    var mac128: [16]u8 = undefined;
 997    var mac256: [32]u8 = undefined;
 998
 999    Aegis128LMac.createWithNonce(&mac256, &msg, &key, &nonce);
1000    Aegis128LMac_128.createWithNonce(&mac128, &msg, &key, &nonce);
1001    try htest.assertEqual("d3f09b2842ad301687d6902c921d7818", &mac128);
1002    try htest.assertEqual("9490e7c89d420c9f37417fa625eb38e8cad53c5cbec55285e8499ea48377f2a3", &mac256);
1003
1004    Aegis128X2Mac.createWithNonce(&mac256, &msg, &key, &nonce);
1005    Aegis128X2Mac_128.createWithNonce(&mac128, &msg, &key, &nonce);
1006    try htest.assertEqual("6873ee34e6b5c59143b6d35c5e4f2c6e", &mac128);
1007    try htest.assertEqual("afcba3fc2d63c8d6c7f2d63f3ec8fbbbaf022e15ac120e78ffa7755abccd959c", &mac256);
1008
1009    Aegis128X4Mac.createWithNonce(&mac256, &msg, &key, &nonce);
1010    Aegis128X4Mac_128.createWithNonce(&mac128, &msg, &key, &nonce);
1011    try htest.assertEqual("c45a98fd9ab8956ce616eb008cfe4e53", &mac128);
1012    try htest.assertEqual("26fdc76f41b1da7aec7779f6e964beae8904e662f05aca8345ae3befb357412a", &mac256);
1013}
1014
1015test "AEGISMAC-256* test vectors" {
1016    const key = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** (32 - 2);
1017    const nonce = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** (32 - 3);
1018    var msg: [35]u8 = undefined;
1019    for (&msg, 0..) |*byte, i| byte.* = @truncate(i);
1020    var mac128: [16]u8 = undefined;
1021    var mac256: [32]u8 = undefined;
1022
1023    Aegis256Mac.createWithNonce(&mac256, &msg, &key, &nonce);
1024    Aegis256Mac_128.createWithNonce(&mac128, &msg, &key, &nonce);
1025    try htest.assertEqual("c08e20cfc56f27195a46c9cef5c162d4", &mac128);
1026    try htest.assertEqual("a5c906ede3d69545c11e20afa360b221f936e946ed2dba3d7c75ad6dc2784126", &mac256);
1027
1028    Aegis256X2Mac.createWithNonce(&mac256, &msg, &key, &nonce);
1029    Aegis256X2Mac_128.createWithNonce(&mac128, &msg, &key, &nonce);
1030    try htest.assertEqual("fb319cb6dd728a764606fb14d37f2a5e", &mac128);
1031    try htest.assertEqual("0844b20ed5147ceae89c7a160263afd4b1382d6b154ecf560ce8a342cb6a8fd1", &mac256);
1032
1033    Aegis256X4Mac.createWithNonce(&mac256, &msg, &key, &nonce);
1034    Aegis256X4Mac_128.createWithNonce(&mac128, &msg, &key, &nonce);
1035    try htest.assertEqual("a51f9bc5beae60cce77f0dbc60761edd", &mac128);
1036    try htest.assertEqual("b36a16ef07c36d75a91f437502f24f545b8dfa88648ed116943c29fead3bf10c", &mac256);
1037}