1 // SPDX-License-Identifier: GPL-2.0-only
3 * aes-ce-glue.c - wrapper code for ARMv8 AES
5 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
10 #include <crypto/aes.h>
11 #include <crypto/internal/simd.h>
12 #include <crypto/internal/skcipher.h>
13 #include <linux/cpufeature.h>
14 #include <linux/module.h>
15 #include <crypto/xts.h>
17 MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
18 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
19 MODULE_LICENSE("GPL v2");
21 /* defined in aes-ce-core.S */
22 asmlinkage u32 ce_aes_sub(u32 input);
23 asmlinkage void ce_aes_invert(void *dst, void *src);
25 asmlinkage void ce_aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
26 int rounds, int blocks);
27 asmlinkage void ce_aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
28 int rounds, int blocks);
30 asmlinkage void ce_aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[],
31 int rounds, int blocks, u8 iv[]);
32 asmlinkage void ce_aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
33 int rounds, int blocks, u8 iv[]);
35 asmlinkage void ce_aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
36 int rounds, int blocks, u8 ctr[]);
38 asmlinkage void ce_aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[],
39 int rounds, int blocks, u8 iv[],
40 u8 const rk2[], int first);
41 asmlinkage void ce_aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[],
42 int rounds, int blocks, u8 iv[],
43 u8 const rk2[], int first);
49 static int num_rounds(struct crypto_aes_ctx *ctx)
52 * # of rounds specified by AES:
53 * 128 bit key 10 rounds
54 * 192 bit key 12 rounds
55 * 256 bit key 14 rounds
56 * => n byte key => 6 + (n/4) rounds
58 return 6 + ctx->key_length / 4;
61 static int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key,
65 * The AES key schedule round constants
67 static u8 const rcon[] = {
68 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
71 u32 kwords = key_len / sizeof(u32);
72 struct aes_block *key_enc, *key_dec;
75 if (key_len != AES_KEYSIZE_128 &&
76 key_len != AES_KEYSIZE_192 &&
77 key_len != AES_KEYSIZE_256)
80 memcpy(ctx->key_enc, in_key, key_len);
81 ctx->key_length = key_len;
84 for (i = 0; i < sizeof(rcon); i++) {
85 u32 *rki = ctx->key_enc + (i * kwords);
86 u32 *rko = rki + kwords;
88 #ifndef CONFIG_CPU_BIG_ENDIAN
89 rko[0] = ror32(ce_aes_sub(rki[kwords - 1]), 8);
90 rko[0] = rko[0] ^ rki[0] ^ rcon[i];
92 rko[0] = rol32(ce_aes_sub(rki[kwords - 1]), 8);
93 rko[0] = rko[0] ^ rki[0] ^ (rcon[i] << 24);
95 rko[1] = rko[0] ^ rki[1];
96 rko[2] = rko[1] ^ rki[2];
97 rko[3] = rko[2] ^ rki[3];
99 if (key_len == AES_KEYSIZE_192) {
102 rko[4] = rko[3] ^ rki[4];
103 rko[5] = rko[4] ^ rki[5];
104 } else if (key_len == AES_KEYSIZE_256) {
107 rko[4] = ce_aes_sub(rko[3]) ^ rki[4];
108 rko[5] = rko[4] ^ rki[5];
109 rko[6] = rko[5] ^ rki[6];
110 rko[7] = rko[6] ^ rki[7];
115 * Generate the decryption keys for the Equivalent Inverse Cipher.
116 * This involves reversing the order of the round keys, and applying
117 * the Inverse Mix Columns transformation on all but the first and
120 key_enc = (struct aes_block *)ctx->key_enc;
121 key_dec = (struct aes_block *)ctx->key_dec;
124 key_dec[0] = key_enc[j];
125 for (i = 1, j--; j > 0; i++, j--)
126 ce_aes_invert(key_dec + i, key_enc + j);
127 key_dec[i] = key_enc[0];
133 static int ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
134 unsigned int key_len)
136 struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
139 ret = ce_aes_expandkey(ctx, in_key, key_len);
143 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
147 struct crypto_aes_xts_ctx {
148 struct crypto_aes_ctx key1;
149 struct crypto_aes_ctx __aligned(8) key2;
152 static int xts_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
153 unsigned int key_len)
155 struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
158 ret = xts_verify_key(tfm, in_key, key_len);
162 ret = ce_aes_expandkey(&ctx->key1, in_key, key_len / 2);
164 ret = ce_aes_expandkey(&ctx->key2, &in_key[key_len / 2],
169 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
173 static int ecb_encrypt(struct skcipher_request *req)
175 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
176 struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
177 struct skcipher_walk walk;
181 err = skcipher_walk_virt(&walk, req, true);
184 while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
185 ce_aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
186 (u8 *)ctx->key_enc, num_rounds(ctx), blocks);
187 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
193 static int ecb_decrypt(struct skcipher_request *req)
195 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
196 struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
197 struct skcipher_walk walk;
201 err = skcipher_walk_virt(&walk, req, true);
204 while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
205 ce_aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
206 (u8 *)ctx->key_dec, num_rounds(ctx), blocks);
207 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
213 static int cbc_encrypt(struct skcipher_request *req)
215 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
216 struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
217 struct skcipher_walk walk;
221 err = skcipher_walk_virt(&walk, req, true);
224 while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
225 ce_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
226 (u8 *)ctx->key_enc, num_rounds(ctx), blocks,
228 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
234 static int cbc_decrypt(struct skcipher_request *req)
236 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
237 struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
238 struct skcipher_walk walk;
242 err = skcipher_walk_virt(&walk, req, true);
245 while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
246 ce_aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
247 (u8 *)ctx->key_dec, num_rounds(ctx), blocks,
249 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
255 static int ctr_encrypt(struct skcipher_request *req)
257 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
258 struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
259 struct skcipher_walk walk;
262 err = skcipher_walk_virt(&walk, req, true);
265 while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
266 ce_aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
267 (u8 *)ctx->key_enc, num_rounds(ctx), blocks,
269 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
272 u8 __aligned(8) tail[AES_BLOCK_SIZE];
273 unsigned int nbytes = walk.nbytes;
274 u8 *tdst = walk.dst.virt.addr;
275 u8 *tsrc = walk.src.virt.addr;
278 * Tell aes_ctr_encrypt() to process a tail block.
282 ce_aes_ctr_encrypt(tail, NULL, (u8 *)ctx->key_enc,
283 num_rounds(ctx), blocks, walk.iv);
284 crypto_xor_cpy(tdst, tsrc, tail, nbytes);
285 err = skcipher_walk_done(&walk, 0);
292 static int xts_encrypt(struct skcipher_request *req)
294 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
295 struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
296 int err, first, rounds = num_rounds(&ctx->key1);
297 struct skcipher_walk walk;
300 err = skcipher_walk_virt(&walk, req, true);
303 for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
304 ce_aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
305 (u8 *)ctx->key1.key_enc, rounds, blocks,
306 walk.iv, (u8 *)ctx->key2.key_enc, first);
307 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
314 static int xts_decrypt(struct skcipher_request *req)
316 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
317 struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
318 int err, first, rounds = num_rounds(&ctx->key1);
319 struct skcipher_walk walk;
322 err = skcipher_walk_virt(&walk, req, true);
325 for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
326 ce_aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
327 (u8 *)ctx->key1.key_dec, rounds, blocks,
328 walk.iv, (u8 *)ctx->key2.key_enc, first);
329 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
336 static struct skcipher_alg aes_algs[] = { {
338 .cra_name = "__ecb(aes)",
339 .cra_driver_name = "__ecb-aes-ce",
341 .cra_flags = CRYPTO_ALG_INTERNAL,
342 .cra_blocksize = AES_BLOCK_SIZE,
343 .cra_ctxsize = sizeof(struct crypto_aes_ctx),
344 .cra_module = THIS_MODULE,
346 .min_keysize = AES_MIN_KEY_SIZE,
347 .max_keysize = AES_MAX_KEY_SIZE,
348 .setkey = ce_aes_setkey,
349 .encrypt = ecb_encrypt,
350 .decrypt = ecb_decrypt,
353 .cra_name = "__cbc(aes)",
354 .cra_driver_name = "__cbc-aes-ce",
356 .cra_flags = CRYPTO_ALG_INTERNAL,
357 .cra_blocksize = AES_BLOCK_SIZE,
358 .cra_ctxsize = sizeof(struct crypto_aes_ctx),
359 .cra_module = THIS_MODULE,
361 .min_keysize = AES_MIN_KEY_SIZE,
362 .max_keysize = AES_MAX_KEY_SIZE,
363 .ivsize = AES_BLOCK_SIZE,
364 .setkey = ce_aes_setkey,
365 .encrypt = cbc_encrypt,
366 .decrypt = cbc_decrypt,
369 .cra_name = "__ctr(aes)",
370 .cra_driver_name = "__ctr-aes-ce",
372 .cra_flags = CRYPTO_ALG_INTERNAL,
374 .cra_ctxsize = sizeof(struct crypto_aes_ctx),
375 .cra_module = THIS_MODULE,
377 .min_keysize = AES_MIN_KEY_SIZE,
378 .max_keysize = AES_MAX_KEY_SIZE,
379 .ivsize = AES_BLOCK_SIZE,
380 .chunksize = AES_BLOCK_SIZE,
381 .setkey = ce_aes_setkey,
382 .encrypt = ctr_encrypt,
383 .decrypt = ctr_encrypt,
386 .cra_name = "__xts(aes)",
387 .cra_driver_name = "__xts-aes-ce",
389 .cra_flags = CRYPTO_ALG_INTERNAL,
390 .cra_blocksize = AES_BLOCK_SIZE,
391 .cra_ctxsize = sizeof(struct crypto_aes_xts_ctx),
392 .cra_module = THIS_MODULE,
394 .min_keysize = 2 * AES_MIN_KEY_SIZE,
395 .max_keysize = 2 * AES_MAX_KEY_SIZE,
396 .ivsize = AES_BLOCK_SIZE,
397 .setkey = xts_set_key,
398 .encrypt = xts_encrypt,
399 .decrypt = xts_decrypt,
402 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
404 static void aes_exit(void)
408 for (i = 0; i < ARRAY_SIZE(aes_simd_algs) && aes_simd_algs[i]; i++)
409 simd_skcipher_free(aes_simd_algs[i]);
411 crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
414 static int __init aes_init(void)
416 struct simd_skcipher_alg *simd;
417 const char *basename;
423 err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
427 for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
428 algname = aes_algs[i].base.cra_name + 2;
429 drvname = aes_algs[i].base.cra_driver_name + 2;
430 basename = aes_algs[i].base.cra_driver_name;
431 simd = simd_skcipher_create_compat(algname, drvname, basename);
434 goto unregister_simds;
436 aes_simd_algs[i] = simd;
446 module_cpu_feature_match(AES, aes_init);
447 module_exit(aes_exit);