2 * linux/arch/arm/crypto/aesbs-glue.c - glue code for NEON bit sliced AES
4 * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
12 #include <crypto/aes.h>
13 #include <crypto/cbc.h>
14 #include <crypto/internal/simd.h>
15 #include <crypto/internal/skcipher.h>
16 #include <linux/module.h>
17 #include <crypto/xts.h>
21 #define BIT_SLICED_KEY_MAXSIZE (128 * (AES_MAXNR - 1) + 2 * AES_BLOCK_SIZE)
26 u8 __aligned(8) bs[BIT_SLICED_KEY_MAXSIZE];
29 asmlinkage void bsaes_enc_key_convert(u8 out[], struct AES_KEY const *in);
30 asmlinkage void bsaes_dec_key_convert(u8 out[], struct AES_KEY const *in);
32 asmlinkage void bsaes_cbc_encrypt(u8 const in[], u8 out[], u32 bytes,
33 struct BS_KEY *key, u8 iv[]);
35 asmlinkage void bsaes_ctr32_encrypt_blocks(u8 const in[], u8 out[], u32 blocks,
36 struct BS_KEY *key, u8 const iv[]);
38 asmlinkage void bsaes_xts_encrypt(u8 const in[], u8 out[], u32 bytes,
39 struct BS_KEY *key, u8 tweak[]);
41 asmlinkage void bsaes_xts_decrypt(u8 const in[], u8 out[], u32 bytes,
42 struct BS_KEY *key, u8 tweak[]);
44 struct aesbs_cbc_ctx {
49 struct aesbs_ctr_ctx {
53 struct aesbs_xts_ctx {
59 static int aesbs_cbc_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
62 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
63 int bits = key_len * 8;
65 if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc)) {
66 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
69 ctx->dec.rk = ctx->enc;
70 private_AES_set_decrypt_key(in_key, bits, &ctx->dec.rk);
71 ctx->dec.converted = 0;
75 static int aesbs_ctr_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
78 struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
79 int bits = key_len * 8;
81 if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc.rk)) {
82 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
85 ctx->enc.converted = 0;
89 static int aesbs_xts_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
92 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
93 int bits = key_len * 4;
96 err = xts_verify_key(tfm, in_key, key_len);
100 if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc.rk)) {
101 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
104 ctx->dec.rk = ctx->enc.rk;
105 private_AES_set_decrypt_key(in_key, bits, &ctx->dec.rk);
106 private_AES_set_encrypt_key(in_key + key_len / 2, bits, &ctx->twkey);
107 ctx->enc.converted = ctx->dec.converted = 0;
111 static inline void aesbs_encrypt_one(struct crypto_skcipher *tfm,
112 const u8 *src, u8 *dst)
114 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
116 AES_encrypt(src, dst, &ctx->enc);
119 static int aesbs_cbc_encrypt(struct skcipher_request *req)
121 return crypto_cbc_encrypt_walk(req, aesbs_encrypt_one);
124 static inline void aesbs_decrypt_one(struct crypto_skcipher *tfm,
125 const u8 *src, u8 *dst)
127 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
129 AES_decrypt(src, dst, &ctx->dec.rk);
132 static int aesbs_cbc_decrypt(struct skcipher_request *req)
134 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
135 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
136 struct skcipher_walk walk;
140 for (err = skcipher_walk_virt(&walk, req, false);
141 (nbytes = walk.nbytes); err = skcipher_walk_done(&walk, nbytes)) {
142 u32 blocks = nbytes / AES_BLOCK_SIZE;
143 u8 *dst = walk.dst.virt.addr;
144 u8 *src = walk.src.virt.addr;
149 bsaes_cbc_encrypt(src, dst, nbytes, &ctx->dec, iv);
151 nbytes %= AES_BLOCK_SIZE;
155 nbytes = crypto_cbc_decrypt_blocks(&walk, tfm,
161 static void inc_be128_ctr(__be32 ctr[], u32 addend)
165 for (i = 3; i >= 0; i--, addend = 1) {
166 u32 n = be32_to_cpu(ctr[i]) + addend;
168 ctr[i] = cpu_to_be32(n);
174 static int aesbs_ctr_encrypt(struct skcipher_request *req)
176 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
177 struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
178 struct skcipher_walk walk;
182 err = skcipher_walk_virt(&walk, req, false);
184 while ((blocks = walk.nbytes / AES_BLOCK_SIZE)) {
185 u32 tail = walk.nbytes % AES_BLOCK_SIZE;
186 __be32 *ctr = (__be32 *)walk.iv;
187 u32 headroom = UINT_MAX - be32_to_cpu(ctr[3]);
189 /* avoid 32 bit counter overflow in the NEON code */
190 if (unlikely(headroom < blocks)) {
191 blocks = headroom + 1;
192 tail = walk.nbytes - blocks * AES_BLOCK_SIZE;
195 bsaes_ctr32_encrypt_blocks(walk.src.virt.addr,
196 walk.dst.virt.addr, blocks,
199 inc_be128_ctr(ctr, blocks);
201 err = skcipher_walk_done(&walk, tail);
204 u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
205 u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
206 u8 ks[AES_BLOCK_SIZE];
208 AES_encrypt(walk.iv, ks, &ctx->enc.rk);
210 memcpy(tdst, tsrc, walk.nbytes);
211 crypto_xor(tdst, ks, walk.nbytes);
212 err = skcipher_walk_done(&walk, 0);
217 static int aesbs_xts_encrypt(struct skcipher_request *req)
219 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
220 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
221 struct skcipher_walk walk;
224 err = skcipher_walk_virt(&walk, req, false);
226 /* generate the initial tweak */
227 AES_encrypt(walk.iv, walk.iv, &ctx->twkey);
229 while (walk.nbytes) {
231 bsaes_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
232 walk.nbytes, &ctx->enc, walk.iv);
234 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
239 static int aesbs_xts_decrypt(struct skcipher_request *req)
241 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
242 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
243 struct skcipher_walk walk;
246 err = skcipher_walk_virt(&walk, req, false);
248 /* generate the initial tweak */
249 AES_encrypt(walk.iv, walk.iv, &ctx->twkey);
251 while (walk.nbytes) {
253 bsaes_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
254 walk.nbytes, &ctx->dec, walk.iv);
256 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
261 static struct skcipher_alg aesbs_algs[] = { {
263 .cra_name = "__cbc(aes)",
264 .cra_driver_name = "__cbc-aes-neonbs",
266 .cra_flags = CRYPTO_ALG_INTERNAL,
267 .cra_blocksize = AES_BLOCK_SIZE,
268 .cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
270 .cra_module = THIS_MODULE,
272 .min_keysize = AES_MIN_KEY_SIZE,
273 .max_keysize = AES_MAX_KEY_SIZE,
274 .ivsize = AES_BLOCK_SIZE,
275 .setkey = aesbs_cbc_set_key,
276 .encrypt = aesbs_cbc_encrypt,
277 .decrypt = aesbs_cbc_decrypt,
280 .cra_name = "__ctr(aes)",
281 .cra_driver_name = "__ctr-aes-neonbs",
283 .cra_flags = CRYPTO_ALG_INTERNAL,
285 .cra_ctxsize = sizeof(struct aesbs_ctr_ctx),
287 .cra_module = THIS_MODULE,
289 .min_keysize = AES_MIN_KEY_SIZE,
290 .max_keysize = AES_MAX_KEY_SIZE,
291 .ivsize = AES_BLOCK_SIZE,
292 .chunksize = AES_BLOCK_SIZE,
293 .setkey = aesbs_ctr_set_key,
294 .encrypt = aesbs_ctr_encrypt,
295 .decrypt = aesbs_ctr_encrypt,
298 .cra_name = "__xts(aes)",
299 .cra_driver_name = "__xts-aes-neonbs",
301 .cra_flags = CRYPTO_ALG_INTERNAL,
302 .cra_blocksize = AES_BLOCK_SIZE,
303 .cra_ctxsize = sizeof(struct aesbs_xts_ctx),
305 .cra_module = THIS_MODULE,
307 .min_keysize = 2 * AES_MIN_KEY_SIZE,
308 .max_keysize = 2 * AES_MAX_KEY_SIZE,
309 .ivsize = AES_BLOCK_SIZE,
310 .setkey = aesbs_xts_set_key,
311 .encrypt = aesbs_xts_encrypt,
312 .decrypt = aesbs_xts_decrypt,
315 struct simd_skcipher_alg *aesbs_simd_algs[ARRAY_SIZE(aesbs_algs)];
317 static void aesbs_mod_exit(void)
321 for (i = 0; i < ARRAY_SIZE(aesbs_simd_algs) && aesbs_simd_algs[i]; i++)
322 simd_skcipher_free(aesbs_simd_algs[i]);
324 crypto_unregister_skciphers(aesbs_algs, ARRAY_SIZE(aesbs_algs));
327 static int __init aesbs_mod_init(void)
329 struct simd_skcipher_alg *simd;
330 const char *basename;
339 err = crypto_register_skciphers(aesbs_algs, ARRAY_SIZE(aesbs_algs));
343 for (i = 0; i < ARRAY_SIZE(aesbs_algs); i++) {
344 algname = aesbs_algs[i].base.cra_name + 2;
345 drvname = aesbs_algs[i].base.cra_driver_name + 2;
346 basename = aesbs_algs[i].base.cra_driver_name;
347 simd = simd_skcipher_create_compat(algname, drvname, basename);
350 goto unregister_simds;
352 aesbs_simd_algs[i] = simd;
362 module_init(aesbs_mod_init);
363 module_exit(aesbs_mod_exit);
365 MODULE_DESCRIPTION("Bit sliced AES in CBC/CTR/XTS modes using NEON");
366 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
367 MODULE_LICENSE("GPL");