authorgravatar for 124872+jedisct1@users.noreply.github.comFrank Denis <124872+jedisct1@users.noreply.github.com> 2025-12-01 11:16:26+01:00
committergravatar for 124872+jedisct1@users.noreply.github.comFrank Denis <124872+jedisct1@users.noreply.github.com> 2025-12-01 11:16:26+01:00
log1d1e2b77802c75b3abb793599aefe4c772a7cfb8
tree12a4aa03dc649a9d9448285328ecdc1f121b914d
parentbfe3317059131ab552f7583b88d6bc82609d198c
parent5e00a0c9b5627195ae9b6e09a9be3e186d4f76d5

Merge pull request 'std.crypto.aes: expose the inverse MixColumns operation' (#30052) from jedisct1/zig:invmixcolumns into master

Reviewed-on: https://codeberg.org/ziglang/zig/pulls/30052

4 files changed, 101 insertions(+), 0 deletions(-)

lib/std/crypto/aes.zig+30
...@@ -108,6 +108,36 @@ test "expand 128-bit key" {...@@ -108,6 +108,36 @@ test "expand 128-bit key" {
108 }108 }
109}109}
110110
111test "invMixColumns" {
112 const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
113 const enc_ctx = Aes128.initEnc(key);
114 const dec_ctx = Aes128.initDec(key);
115
116 for (1..10) |i| {
117 const enc_rk = enc_ctx.key_schedule.round_keys[10 - i];
118 const dec_rk = dec_ctx.key_schedule.round_keys[i];
119 const computed = enc_rk.invMixColumns();
120 try testing.expectEqualSlices(u8, &dec_rk.toBytes(), &computed.toBytes());
121 }
122}
123
124test "BlockVec invMixColumns" {
125 const input = [_]u8{
126 0x5f, 0x57, 0xf7, 0x1d, 0x72, 0xf5, 0xbe, 0xb9, 0x64, 0xbc, 0x3b, 0xf9, 0x15, 0x92, 0x29, 0x1a,
127 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c,
128 };
129
130 const vec2 = BlockVec(2).fromBytes(&input);
131 const result_vec = vec2.invMixColumns();
132 const result_bytes = result_vec.toBytes();
133
134 for (0..2) |i| {
135 const block = Block.fromBytes(input[i * 16 ..][0..16]);
136 const expected = block.invMixColumns().toBytes();
137 try testing.expectEqualSlices(u8, &expected, result_bytes[i * 16 ..][0..16]);
138 }
139}
140
111test "expand 256-bit key" {141test "expand 256-bit key" {
112 const key = [_]u8{142 const key = [_]u8{
113 0x60, 0x3d, 0xeb, 0x10,143 0x60, 0x3d, 0xeb, 0x10,
lib/std/crypto/aes/aesni.zig+22
...@@ -96,6 +96,17 @@ pub const Block = struct {...@@ -96,6 +96,17 @@ pub const Block = struct {
96 return Block{ .repr = block1.repr | block2.repr };96 return Block{ .repr = block1.repr | block2.repr };
97 }97 }
9898
99 /// Apply the inverse MixColumns operation to a block.
100 pub fn invMixColumns(block: Block) Block {
101 return Block{
102 .repr = asm (
103 \\ vaesimc %[in], %[out]
104 : [out] "=x" (-> Repr),
105 : [in] "x" (block.repr),
106 ),
107 };
108 }
109
99 /// Perform operations on multiple blocks in parallel.110 /// Perform operations on multiple blocks in parallel.
100 pub const parallel = struct {111 pub const parallel = struct {
101 const cpu = std.Target.x86.cpu;112 const cpu = std.Target.x86.cpu;
...@@ -308,6 +319,17 @@ pub fn BlockVec(comptime blocks_count: comptime_int) type {...@@ -308,6 +319,17 @@ pub fn BlockVec(comptime blocks_count: comptime_int) type {
308 }319 }
309 return out;320 return out;
310 }321 }
322
323 /// Apply the inverse MixColumns operation to each block in the vector.
324 pub fn invMixColumns(block_vec: Self) Self {
325 var out_bytes: [blocks_count * 16]u8 = undefined;
326 const in_bytes = block_vec.toBytes();
327 inline for (0..blocks_count) |i| {
328 const block = Block.fromBytes(in_bytes[i * 16 ..][0..16]);
329 out_bytes[i * 16 ..][0..16].* = block.invMixColumns().toBytes();
330 }
331 return fromBytes(&out_bytes);
332 }
311 };333 };
312}334}
313335
lib/std/crypto/aes/armcrypto.zig+20
...@@ -99,6 +99,17 @@ pub const Block = struct {...@@ -99,6 +99,17 @@ pub const Block = struct {
99 return Block{ .repr = block1.repr | block2.repr };99 return Block{ .repr = block1.repr | block2.repr };
100 }100 }
101101
102 /// Apply the inverse MixColumns operation to a block.
103 pub fn invMixColumns(block: Block) Block {
104 return Block{
105 .repr = asm (
106 \\ aesimc %[out].16b, %[in].16b
107 : [out] "=x" (-> Repr),
108 : [in] "x" (block.repr),
109 ),
110 };
111 }
112
102 /// Perform operations on multiple blocks in parallel.113 /// Perform operations on multiple blocks in parallel.
103 pub const parallel = struct {114 pub const parallel = struct {
104 /// The recommended number of AES encryption/decryption to perform in parallel for the chosen implementation.115 /// The recommended number of AES encryption/decryption to perform in parallel for the chosen implementation.
...@@ -275,6 +286,15 @@ pub fn BlockVec(comptime blocks_count: comptime_int) type {...@@ -275,6 +286,15 @@ pub fn BlockVec(comptime blocks_count: comptime_int) type {
275 }286 }
276 return out;287 return out;
277 }288 }
289
290 /// Apply the inverse MixColumns operation to each block in the vector.
291 pub fn invMixColumns(block_vec: Self) Self {
292 var out: Self = undefined;
293 inline for (0..native_words) |i| {
294 out.repr[i] = block_vec.repr[i].invMixColumns();
295 }
296 return out;
297 }
278 };298 };
279}299}
280300
lib/std/crypto/aes/soft.zig+29
...@@ -265,6 +265,26 @@ pub const Block = struct {...@@ -265,6 +265,26 @@ pub const Block = struct {
265 return Block{ .repr = x };265 return Block{ .repr = x };
266 }266 }
267267
268 /// Apply the inverse MixColumns operation to a block.
269 pub fn invMixColumns(block: Block) Block {
270 var out: Repr = undefined;
271 inline for (0..4) |i| {
272 const col = block.repr[i];
273 const b0: u8 = @truncate(col);
274 const b1: u8 = @truncate(col >> 8);
275 const b2: u8 = @truncate(col >> 16);
276 const b3: u8 = @truncate(col >> 24);
277
278 const r0 = mul(0x0e, b0) ^ mul(0x0b, b1) ^ mul(0x0d, b2) ^ mul(0x09, b3);
279 const r1 = mul(0x09, b0) ^ mul(0x0e, b1) ^ mul(0x0b, b2) ^ mul(0x0d, b3);
280 const r2 = mul(0x0d, b0) ^ mul(0x09, b1) ^ mul(0x0e, b2) ^ mul(0x0b, b3);
281 const r3 = mul(0x0b, b0) ^ mul(0x0d, b1) ^ mul(0x09, b2) ^ mul(0x0e, b3);
282
283 out[i] = @as(u32, r0) | (@as(u32, r1) << 8) | (@as(u32, r2) << 16) | (@as(u32, r3) << 24);
284 }
285 return Block{ .repr = out };
286 }
287
268 /// Perform operations on multiple blocks in parallel.288 /// Perform operations on multiple blocks in parallel.
269 pub const parallel = struct {289 pub const parallel = struct {
270 /// The recommended number of AES encryption/decryption to perform in parallel for the chosen implementation.290 /// The recommended number of AES encryption/decryption to perform in parallel for the chosen implementation.
...@@ -441,6 +461,15 @@ pub fn BlockVec(comptime blocks_count: comptime_int) type {...@@ -441,6 +461,15 @@ pub fn BlockVec(comptime blocks_count: comptime_int) type {
441 }461 }
442 return out;462 return out;
443 }463 }
464
465 /// Apply the inverse MixColumns operation to each block in the vector.
466 pub fn invMixColumns(block_vec: Self) Self {
467 var out: Self = undefined;
468 for (0..native_words) |i| {
469 out.repr[i] = block_vec.repr[i].invMixColumns();
470 }
471 return out;
472 }
444 };473 };
445}474}
446475