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7c185371 TL |
1 | /* |
2 | * AMD Cryptographic Coprocessor (CCP) AES CMAC crypto API support | |
3 | * | |
4 | * Copyright (C) 2013 Advanced Micro Devices, Inc. | |
5 | * | |
6 | * Author: Tom Lendacky <thomas.lendacky@amd.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/scatterlist.h> | |
17 | #include <linux/crypto.h> | |
18 | #include <crypto/algapi.h> | |
19 | #include <crypto/aes.h> | |
20 | #include <crypto/hash.h> | |
21 | #include <crypto/internal/hash.h> | |
22 | #include <crypto/scatterwalk.h> | |
23 | ||
24 | #include "ccp-crypto.h" | |
25 | ||
7c185371 TL |
26 | static int ccp_aes_cmac_complete(struct crypto_async_request *async_req, |
27 | int ret) | |
28 | { | |
29 | struct ahash_request *req = ahash_request_cast(async_req); | |
30 | struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); | |
31 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); | |
32 | unsigned int digest_size = crypto_ahash_digestsize(tfm); | |
33 | ||
34 | if (ret) | |
35 | goto e_free; | |
36 | ||
37 | if (rctx->hash_rem) { | |
38 | /* Save remaining data to buffer */ | |
81a59f00 | 39 | unsigned int offset = rctx->nbytes - rctx->hash_rem; |
8db88467 | 40 | |
81a59f00 TL |
41 | scatterwalk_map_and_copy(rctx->buf, rctx->src, |
42 | offset, rctx->hash_rem, 0); | |
7c185371 | 43 | rctx->buf_count = rctx->hash_rem; |
8db88467 | 44 | } else { |
7c185371 | 45 | rctx->buf_count = 0; |
8db88467 | 46 | } |
7c185371 | 47 | |
393897c5 TL |
48 | /* Update result area if supplied */ |
49 | if (req->result) | |
50 | memcpy(req->result, rctx->iv, digest_size); | |
7c185371 TL |
51 | |
52 | e_free: | |
53 | sg_free_table(&rctx->data_sg); | |
54 | ||
55 | return ret; | |
56 | } | |
57 | ||
58 | static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes, | |
59 | unsigned int final) | |
60 | { | |
61 | struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); | |
62 | struct ccp_ctx *ctx = crypto_ahash_ctx(tfm); | |
63 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); | |
64 | struct scatterlist *sg, *cmac_key_sg = NULL; | |
65 | unsigned int block_size = | |
66 | crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); | |
81a59f00 | 67 | unsigned int need_pad, sg_count; |
5258de8a | 68 | gfp_t gfp; |
81a59f00 | 69 | u64 len; |
7c185371 TL |
70 | int ret; |
71 | ||
369f3dab | 72 | if (!ctx->u.aes.key_len) |
7c185371 | 73 | return -EINVAL; |
7c185371 TL |
74 | |
75 | if (nbytes) | |
76 | rctx->null_msg = 0; | |
77 | ||
81a59f00 TL |
78 | len = (u64)rctx->buf_count + (u64)nbytes; |
79 | ||
80 | if (!final && (len <= block_size)) { | |
7c185371 TL |
81 | scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src, |
82 | 0, nbytes, 0); | |
83 | rctx->buf_count += nbytes; | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
81a59f00 TL |
88 | rctx->src = req->src; |
89 | rctx->nbytes = nbytes; | |
7c185371 TL |
90 | |
91 | rctx->final = final; | |
81a59f00 TL |
92 | rctx->hash_rem = final ? 0 : len & (block_size - 1); |
93 | rctx->hash_cnt = len - rctx->hash_rem; | |
94 | if (!final && !rctx->hash_rem) { | |
7c185371 TL |
95 | /* CCP can't do zero length final, so keep some data around */ |
96 | rctx->hash_cnt -= block_size; | |
97 | rctx->hash_rem = block_size; | |
98 | } | |
99 | ||
100 | if (final && (rctx->null_msg || (len & (block_size - 1)))) | |
101 | need_pad = 1; | |
102 | else | |
103 | need_pad = 0; | |
104 | ||
105 | sg_init_one(&rctx->iv_sg, rctx->iv, sizeof(rctx->iv)); | |
106 | ||
107 | /* Build the data scatterlist table - allocate enough entries for all | |
108 | * possible data pieces (buffer, input data, padding) | |
109 | */ | |
110 | sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2; | |
5258de8a TL |
111 | gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? |
112 | GFP_KERNEL : GFP_ATOMIC; | |
113 | ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp); | |
7c185371 TL |
114 | if (ret) |
115 | return ret; | |
116 | ||
117 | sg = NULL; | |
118 | if (rctx->buf_count) { | |
119 | sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); | |
120 | sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg); | |
121 | } | |
122 | ||
123 | if (nbytes) | |
124 | sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src); | |
125 | ||
126 | if (need_pad) { | |
127 | int pad_length = block_size - (len & (block_size - 1)); | |
128 | ||
129 | rctx->hash_cnt += pad_length; | |
130 | ||
131 | memset(rctx->pad, 0, sizeof(rctx->pad)); | |
132 | rctx->pad[0] = 0x80; | |
133 | sg_init_one(&rctx->pad_sg, rctx->pad, pad_length); | |
134 | sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg); | |
135 | } | |
77dc4a51 | 136 | if (sg) { |
7c185371 | 137 | sg_mark_end(sg); |
77dc4a51 TL |
138 | sg = rctx->data_sg.sgl; |
139 | } | |
7c185371 TL |
140 | |
141 | /* Initialize the K1/K2 scatterlist */ | |
142 | if (final) | |
143 | cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg | |
144 | : &ctx->u.aes.k1_sg; | |
145 | ||
146 | memset(&rctx->cmd, 0, sizeof(rctx->cmd)); | |
147 | INIT_LIST_HEAD(&rctx->cmd.entry); | |
148 | rctx->cmd.engine = CCP_ENGINE_AES; | |
149 | rctx->cmd.u.aes.type = ctx->u.aes.type; | |
150 | rctx->cmd.u.aes.mode = ctx->u.aes.mode; | |
151 | rctx->cmd.u.aes.action = CCP_AES_ACTION_ENCRYPT; | |
152 | rctx->cmd.u.aes.key = &ctx->u.aes.key_sg; | |
153 | rctx->cmd.u.aes.key_len = ctx->u.aes.key_len; | |
154 | rctx->cmd.u.aes.iv = &rctx->iv_sg; | |
155 | rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE; | |
77dc4a51 | 156 | rctx->cmd.u.aes.src = sg; |
7c185371 TL |
157 | rctx->cmd.u.aes.src_len = rctx->hash_cnt; |
158 | rctx->cmd.u.aes.dst = NULL; | |
159 | rctx->cmd.u.aes.cmac_key = cmac_key_sg; | |
160 | rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len; | |
161 | rctx->cmd.u.aes.cmac_final = final; | |
162 | ||
163 | ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); | |
164 | ||
165 | return ret; | |
166 | } | |
167 | ||
168 | static int ccp_aes_cmac_init(struct ahash_request *req) | |
169 | { | |
170 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); | |
171 | ||
172 | memset(rctx, 0, sizeof(*rctx)); | |
173 | ||
174 | rctx->null_msg = 1; | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | static int ccp_aes_cmac_update(struct ahash_request *req) | |
180 | { | |
181 | return ccp_do_cmac_update(req, req->nbytes, 0); | |
182 | } | |
183 | ||
184 | static int ccp_aes_cmac_final(struct ahash_request *req) | |
185 | { | |
186 | return ccp_do_cmac_update(req, 0, 1); | |
187 | } | |
188 | ||
189 | static int ccp_aes_cmac_finup(struct ahash_request *req) | |
190 | { | |
191 | return ccp_do_cmac_update(req, req->nbytes, 1); | |
192 | } | |
193 | ||
194 | static int ccp_aes_cmac_digest(struct ahash_request *req) | |
195 | { | |
196 | int ret; | |
197 | ||
198 | ret = ccp_aes_cmac_init(req); | |
199 | if (ret) | |
200 | return ret; | |
201 | ||
82d1585b | 202 | return ccp_aes_cmac_finup(req); |
7c185371 TL |
203 | } |
204 | ||
205 | static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key, | |
8db88467 | 206 | unsigned int key_len) |
7c185371 TL |
207 | { |
208 | struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm)); | |
209 | struct ccp_crypto_ahash_alg *alg = | |
210 | ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm)); | |
211 | u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo; | |
212 | u64 rb_hi = 0x00, rb_lo = 0x87; | |
213 | __be64 *gk; | |
214 | int ret; | |
215 | ||
216 | switch (key_len) { | |
217 | case AES_KEYSIZE_128: | |
218 | ctx->u.aes.type = CCP_AES_TYPE_128; | |
219 | break; | |
220 | case AES_KEYSIZE_192: | |
221 | ctx->u.aes.type = CCP_AES_TYPE_192; | |
222 | break; | |
223 | case AES_KEYSIZE_256: | |
224 | ctx->u.aes.type = CCP_AES_TYPE_256; | |
225 | break; | |
226 | default: | |
227 | crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); | |
228 | return -EINVAL; | |
229 | } | |
230 | ctx->u.aes.mode = alg->mode; | |
231 | ||
232 | /* Set to zero until complete */ | |
233 | ctx->u.aes.key_len = 0; | |
234 | ||
235 | /* Set the key for the AES cipher used to generate the keys */ | |
236 | ret = crypto_cipher_setkey(ctx->u.aes.tfm_cipher, key, key_len); | |
237 | if (ret) | |
238 | return ret; | |
239 | ||
240 | /* Encrypt a block of zeroes - use key area in context */ | |
241 | memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); | |
242 | crypto_cipher_encrypt_one(ctx->u.aes.tfm_cipher, ctx->u.aes.key, | |
243 | ctx->u.aes.key); | |
244 | ||
245 | /* Generate K1 and K2 */ | |
246 | k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key)); | |
247 | k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1)); | |
248 | ||
249 | k1_hi = (k0_hi << 1) | (k0_lo >> 63); | |
250 | k1_lo = k0_lo << 1; | |
251 | if (ctx->u.aes.key[0] & 0x80) { | |
252 | k1_hi ^= rb_hi; | |
253 | k1_lo ^= rb_lo; | |
254 | } | |
255 | gk = (__be64 *)ctx->u.aes.k1; | |
256 | *gk = cpu_to_be64(k1_hi); | |
257 | gk++; | |
258 | *gk = cpu_to_be64(k1_lo); | |
259 | ||
260 | k2_hi = (k1_hi << 1) | (k1_lo >> 63); | |
261 | k2_lo = k1_lo << 1; | |
262 | if (ctx->u.aes.k1[0] & 0x80) { | |
263 | k2_hi ^= rb_hi; | |
264 | k2_lo ^= rb_lo; | |
265 | } | |
266 | gk = (__be64 *)ctx->u.aes.k2; | |
267 | *gk = cpu_to_be64(k2_hi); | |
268 | gk++; | |
269 | *gk = cpu_to_be64(k2_lo); | |
270 | ||
271 | ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1); | |
272 | sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1)); | |
273 | sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2)); | |
274 | ||
275 | /* Save the supplied key */ | |
276 | memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); | |
277 | memcpy(ctx->u.aes.key, key, key_len); | |
278 | ctx->u.aes.key_len = key_len; | |
279 | sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); | |
280 | ||
281 | return ret; | |
282 | } | |
283 | ||
284 | static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm) | |
285 | { | |
286 | struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); | |
287 | struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); | |
288 | struct crypto_cipher *cipher_tfm; | |
289 | ||
290 | ctx->complete = ccp_aes_cmac_complete; | |
291 | ctx->u.aes.key_len = 0; | |
292 | ||
293 | crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_aes_cmac_req_ctx)); | |
294 | ||
295 | cipher_tfm = crypto_alloc_cipher("aes", 0, | |
8db88467 TL |
296 | CRYPTO_ALG_ASYNC | |
297 | CRYPTO_ALG_NEED_FALLBACK); | |
7c185371 TL |
298 | if (IS_ERR(cipher_tfm)) { |
299 | pr_warn("could not load aes cipher driver\n"); | |
300 | return PTR_ERR(cipher_tfm); | |
301 | } | |
302 | ctx->u.aes.tfm_cipher = cipher_tfm; | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
307 | static void ccp_aes_cmac_cra_exit(struct crypto_tfm *tfm) | |
308 | { | |
309 | struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); | |
310 | ||
311 | if (ctx->u.aes.tfm_cipher) | |
312 | crypto_free_cipher(ctx->u.aes.tfm_cipher); | |
313 | ctx->u.aes.tfm_cipher = NULL; | |
314 | } | |
315 | ||
316 | int ccp_register_aes_cmac_algs(struct list_head *head) | |
317 | { | |
318 | struct ccp_crypto_ahash_alg *ccp_alg; | |
319 | struct ahash_alg *alg; | |
320 | struct hash_alg_common *halg; | |
321 | struct crypto_alg *base; | |
322 | int ret; | |
323 | ||
324 | ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); | |
325 | if (!ccp_alg) | |
326 | return -ENOMEM; | |
327 | ||
328 | INIT_LIST_HEAD(&ccp_alg->entry); | |
329 | ccp_alg->mode = CCP_AES_MODE_CMAC; | |
330 | ||
331 | alg = &ccp_alg->alg; | |
332 | alg->init = ccp_aes_cmac_init; | |
333 | alg->update = ccp_aes_cmac_update; | |
334 | alg->final = ccp_aes_cmac_final; | |
335 | alg->finup = ccp_aes_cmac_finup; | |
336 | alg->digest = ccp_aes_cmac_digest; | |
337 | alg->setkey = ccp_aes_cmac_setkey; | |
338 | ||
339 | halg = &alg->halg; | |
340 | halg->digestsize = AES_BLOCK_SIZE; | |
341 | ||
342 | base = &halg->base; | |
343 | snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)"); | |
344 | snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp"); | |
345 | base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | | |
346 | CRYPTO_ALG_KERN_DRIVER_ONLY | | |
347 | CRYPTO_ALG_NEED_FALLBACK; | |
348 | base->cra_blocksize = AES_BLOCK_SIZE; | |
349 | base->cra_ctxsize = sizeof(struct ccp_ctx); | |
350 | base->cra_priority = CCP_CRA_PRIORITY; | |
351 | base->cra_type = &crypto_ahash_type; | |
352 | base->cra_init = ccp_aes_cmac_cra_init; | |
353 | base->cra_exit = ccp_aes_cmac_cra_exit; | |
354 | base->cra_module = THIS_MODULE; | |
355 | ||
356 | ret = crypto_register_ahash(alg); | |
357 | if (ret) { | |
358 | pr_err("%s ahash algorithm registration error (%d)\n", | |
8db88467 | 359 | base->cra_name, ret); |
7c185371 TL |
360 | kfree(ccp_alg); |
361 | return ret; | |
362 | } | |
363 | ||
364 | list_add(&ccp_alg->entry, head); | |
365 | ||
366 | return 0; | |
367 | } |