1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * AMD Cryptographic Coprocessor (CCP) AES CMAC crypto API support |
4 | * |
5 | * Copyright (C) 2013,2018 Advanced Micro Devices, Inc. |
6 | * |
7 | * Author: Tom Lendacky <thomas.lendacky@amd.com> |
8 | */ |
9 | |
10 | #include <linux/module.h> |
11 | #include <linux/sched.h> |
12 | #include <linux/delay.h> |
13 | #include <linux/scatterlist.h> |
14 | #include <linux/crypto.h> |
15 | #include <crypto/algapi.h> |
16 | #include <crypto/aes.h> |
17 | #include <crypto/hash.h> |
18 | #include <crypto/internal/hash.h> |
19 | #include <crypto/scatterwalk.h> |
20 | |
21 | #include "ccp-crypto.h" |
22 | |
23 | static int ccp_aes_cmac_complete(struct crypto_async_request *async_req, |
24 | int ret) |
25 | { |
26 | struct ahash_request *req = ahash_request_cast(req: async_req); |
27 | struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); |
28 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); |
29 | unsigned int digest_size = crypto_ahash_digestsize(tfm); |
30 | |
31 | if (ret) |
32 | goto e_free; |
33 | |
34 | if (rctx->hash_rem) { |
35 | /* Save remaining data to buffer */ |
36 | unsigned int offset = rctx->nbytes - rctx->hash_rem; |
37 | |
38 | scatterwalk_map_and_copy(buf: rctx->buf, sg: rctx->src, |
39 | start: offset, nbytes: rctx->hash_rem, out: 0); |
40 | rctx->buf_count = rctx->hash_rem; |
41 | } else { |
42 | rctx->buf_count = 0; |
43 | } |
44 | |
45 | /* Update result area if supplied */ |
46 | if (req->result && rctx->final) |
47 | memcpy(req->result, rctx->iv, digest_size); |
48 | |
49 | e_free: |
50 | sg_free_table(&rctx->data_sg); |
51 | |
52 | return ret; |
53 | } |
54 | |
55 | static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes, |
56 | unsigned int final) |
57 | { |
58 | struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); |
59 | struct ccp_ctx *ctx = crypto_ahash_ctx_dma(tfm); |
60 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); |
61 | struct scatterlist *sg, *cmac_key_sg = NULL; |
62 | unsigned int block_size = |
63 | crypto_tfm_alg_blocksize(tfm: crypto_ahash_tfm(tfm)); |
64 | unsigned int need_pad, sg_count; |
65 | gfp_t gfp; |
66 | u64 len; |
67 | int ret; |
68 | |
69 | if (!ctx->u.aes.key_len) |
70 | return -EINVAL; |
71 | |
72 | if (nbytes) |
73 | rctx->null_msg = 0; |
74 | |
75 | len = (u64)rctx->buf_count + (u64)nbytes; |
76 | |
77 | if (!final && (len <= block_size)) { |
78 | scatterwalk_map_and_copy(buf: rctx->buf + rctx->buf_count, sg: req->src, |
79 | start: 0, nbytes, out: 0); |
80 | rctx->buf_count += nbytes; |
81 | |
82 | return 0; |
83 | } |
84 | |
85 | rctx->src = req->src; |
86 | rctx->nbytes = nbytes; |
87 | |
88 | rctx->final = final; |
89 | rctx->hash_rem = final ? 0 : len & (block_size - 1); |
90 | rctx->hash_cnt = len - rctx->hash_rem; |
91 | if (!final && !rctx->hash_rem) { |
92 | /* CCP can't do zero length final, so keep some data around */ |
93 | rctx->hash_cnt -= block_size; |
94 | rctx->hash_rem = block_size; |
95 | } |
96 | |
97 | if (final && (rctx->null_msg || (len & (block_size - 1)))) |
98 | need_pad = 1; |
99 | else |
100 | need_pad = 0; |
101 | |
102 | sg_init_one(&rctx->iv_sg, rctx->iv, sizeof(rctx->iv)); |
103 | |
104 | /* Build the data scatterlist table - allocate enough entries for all |
105 | * possible data pieces (buffer, input data, padding) |
106 | */ |
107 | sg_count = (nbytes) ? sg_nents(sg: req->src) + 2 : 2; |
108 | gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? |
109 | GFP_KERNEL : GFP_ATOMIC; |
110 | ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp); |
111 | if (ret) |
112 | return ret; |
113 | |
114 | sg = NULL; |
115 | if (rctx->buf_count) { |
116 | sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); |
117 | sg = ccp_crypto_sg_table_add(table: &rctx->data_sg, sg_add: &rctx->buf_sg); |
118 | if (!sg) { |
119 | ret = -EINVAL; |
120 | goto e_free; |
121 | } |
122 | } |
123 | |
124 | if (nbytes) { |
125 | sg = ccp_crypto_sg_table_add(table: &rctx->data_sg, sg_add: req->src); |
126 | if (!sg) { |
127 | ret = -EINVAL; |
128 | goto e_free; |
129 | } |
130 | } |
131 | |
132 | if (need_pad) { |
133 | int pad_length = block_size - (len & (block_size - 1)); |
134 | |
135 | rctx->hash_cnt += pad_length; |
136 | |
137 | memset(rctx->pad, 0, sizeof(rctx->pad)); |
138 | rctx->pad[0] = 0x80; |
139 | sg_init_one(&rctx->pad_sg, rctx->pad, pad_length); |
140 | sg = ccp_crypto_sg_table_add(table: &rctx->data_sg, sg_add: &rctx->pad_sg); |
141 | if (!sg) { |
142 | ret = -EINVAL; |
143 | goto e_free; |
144 | } |
145 | } |
146 | if (sg) { |
147 | sg_mark_end(sg); |
148 | sg = rctx->data_sg.sgl; |
149 | } |
150 | |
151 | /* Initialize the K1/K2 scatterlist */ |
152 | if (final) |
153 | cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg |
154 | : &ctx->u.aes.k1_sg; |
155 | |
156 | memset(&rctx->cmd, 0, sizeof(rctx->cmd)); |
157 | INIT_LIST_HEAD(list: &rctx->cmd.entry); |
158 | rctx->cmd.engine = CCP_ENGINE_AES; |
159 | rctx->cmd.u.aes.type = ctx->u.aes.type; |
160 | rctx->cmd.u.aes.mode = ctx->u.aes.mode; |
161 | rctx->cmd.u.aes.action = CCP_AES_ACTION_ENCRYPT; |
162 | rctx->cmd.u.aes.key = &ctx->u.aes.key_sg; |
163 | rctx->cmd.u.aes.key_len = ctx->u.aes.key_len; |
164 | rctx->cmd.u.aes.iv = &rctx->iv_sg; |
165 | rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE; |
166 | rctx->cmd.u.aes.src = sg; |
167 | rctx->cmd.u.aes.src_len = rctx->hash_cnt; |
168 | rctx->cmd.u.aes.dst = NULL; |
169 | rctx->cmd.u.aes.cmac_key = cmac_key_sg; |
170 | rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len; |
171 | rctx->cmd.u.aes.cmac_final = final; |
172 | |
173 | ret = ccp_crypto_enqueue_request(req: &req->base, cmd: &rctx->cmd); |
174 | |
175 | return ret; |
176 | |
177 | e_free: |
178 | sg_free_table(&rctx->data_sg); |
179 | |
180 | return ret; |
181 | } |
182 | |
183 | static int ccp_aes_cmac_init(struct ahash_request *req) |
184 | { |
185 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); |
186 | |
187 | memset(rctx, 0, sizeof(*rctx)); |
188 | |
189 | rctx->null_msg = 1; |
190 | |
191 | return 0; |
192 | } |
193 | |
194 | static int ccp_aes_cmac_update(struct ahash_request *req) |
195 | { |
196 | return ccp_do_cmac_update(req, nbytes: req->nbytes, final: 0); |
197 | } |
198 | |
199 | static int ccp_aes_cmac_final(struct ahash_request *req) |
200 | { |
201 | return ccp_do_cmac_update(req, nbytes: 0, final: 1); |
202 | } |
203 | |
204 | static int ccp_aes_cmac_finup(struct ahash_request *req) |
205 | { |
206 | return ccp_do_cmac_update(req, nbytes: req->nbytes, final: 1); |
207 | } |
208 | |
209 | static int ccp_aes_cmac_digest(struct ahash_request *req) |
210 | { |
211 | int ret; |
212 | |
213 | ret = ccp_aes_cmac_init(req); |
214 | if (ret) |
215 | return ret; |
216 | |
217 | return ccp_aes_cmac_finup(req); |
218 | } |
219 | |
220 | static int ccp_aes_cmac_export(struct ahash_request *req, void *out) |
221 | { |
222 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); |
223 | struct ccp_aes_cmac_exp_ctx state; |
224 | |
225 | /* Don't let anything leak to 'out' */ |
226 | memset(&state, 0, sizeof(state)); |
227 | |
228 | state.null_msg = rctx->null_msg; |
229 | memcpy(state.iv, rctx->iv, sizeof(state.iv)); |
230 | state.buf_count = rctx->buf_count; |
231 | memcpy(state.buf, rctx->buf, sizeof(state.buf)); |
232 | |
233 | /* 'out' may not be aligned so memcpy from local variable */ |
234 | memcpy(out, &state, sizeof(state)); |
235 | |
236 | return 0; |
237 | } |
238 | |
239 | static int ccp_aes_cmac_import(struct ahash_request *req, const void *in) |
240 | { |
241 | struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); |
242 | struct ccp_aes_cmac_exp_ctx state; |
243 | |
244 | /* 'in' may not be aligned so memcpy to local variable */ |
245 | memcpy(&state, in, sizeof(state)); |
246 | |
247 | memset(rctx, 0, sizeof(*rctx)); |
248 | rctx->null_msg = state.null_msg; |
249 | memcpy(rctx->iv, state.iv, sizeof(rctx->iv)); |
250 | rctx->buf_count = state.buf_count; |
251 | memcpy(rctx->buf, state.buf, sizeof(rctx->buf)); |
252 | |
253 | return 0; |
254 | } |
255 | |
256 | static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key, |
257 | unsigned int key_len) |
258 | { |
259 | struct ccp_ctx *ctx = crypto_ahash_ctx_dma(tfm); |
260 | struct ccp_crypto_ahash_alg *alg = |
261 | ccp_crypto_ahash_alg(tfm: crypto_ahash_tfm(tfm)); |
262 | u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo; |
263 | u64 rb_hi = 0x00, rb_lo = 0x87; |
264 | struct crypto_aes_ctx aes; |
265 | __be64 *gk; |
266 | int ret; |
267 | |
268 | switch (key_len) { |
269 | case AES_KEYSIZE_128: |
270 | ctx->u.aes.type = CCP_AES_TYPE_128; |
271 | break; |
272 | case AES_KEYSIZE_192: |
273 | ctx->u.aes.type = CCP_AES_TYPE_192; |
274 | break; |
275 | case AES_KEYSIZE_256: |
276 | ctx->u.aes.type = CCP_AES_TYPE_256; |
277 | break; |
278 | default: |
279 | return -EINVAL; |
280 | } |
281 | ctx->u.aes.mode = alg->mode; |
282 | |
283 | /* Set to zero until complete */ |
284 | ctx->u.aes.key_len = 0; |
285 | |
286 | /* Set the key for the AES cipher used to generate the keys */ |
287 | ret = aes_expandkey(ctx: &aes, in_key: key, key_len); |
288 | if (ret) |
289 | return ret; |
290 | |
291 | /* Encrypt a block of zeroes - use key area in context */ |
292 | memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); |
293 | aes_encrypt(ctx: &aes, out: ctx->u.aes.key, in: ctx->u.aes.key); |
294 | memzero_explicit(s: &aes, count: sizeof(aes)); |
295 | |
296 | /* Generate K1 and K2 */ |
297 | k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key)); |
298 | k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1)); |
299 | |
300 | k1_hi = (k0_hi << 1) | (k0_lo >> 63); |
301 | k1_lo = k0_lo << 1; |
302 | if (ctx->u.aes.key[0] & 0x80) { |
303 | k1_hi ^= rb_hi; |
304 | k1_lo ^= rb_lo; |
305 | } |
306 | gk = (__be64 *)ctx->u.aes.k1; |
307 | *gk = cpu_to_be64(k1_hi); |
308 | gk++; |
309 | *gk = cpu_to_be64(k1_lo); |
310 | |
311 | k2_hi = (k1_hi << 1) | (k1_lo >> 63); |
312 | k2_lo = k1_lo << 1; |
313 | if (ctx->u.aes.k1[0] & 0x80) { |
314 | k2_hi ^= rb_hi; |
315 | k2_lo ^= rb_lo; |
316 | } |
317 | gk = (__be64 *)ctx->u.aes.k2; |
318 | *gk = cpu_to_be64(k2_hi); |
319 | gk++; |
320 | *gk = cpu_to_be64(k2_lo); |
321 | |
322 | ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1); |
323 | sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1)); |
324 | sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2)); |
325 | |
326 | /* Save the supplied key */ |
327 | memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); |
328 | memcpy(ctx->u.aes.key, key, key_len); |
329 | ctx->u.aes.key_len = key_len; |
330 | sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); |
331 | |
332 | return ret; |
333 | } |
334 | |
335 | static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm) |
336 | { |
337 | struct ccp_ctx *ctx = crypto_tfm_ctx_dma(tfm); |
338 | struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); |
339 | |
340 | ctx->complete = ccp_aes_cmac_complete; |
341 | ctx->u.aes.key_len = 0; |
342 | |
343 | crypto_ahash_set_reqsize_dma(ahash, |
344 | reqsize: sizeof(struct ccp_aes_cmac_req_ctx)); |
345 | |
346 | return 0; |
347 | } |
348 | |
349 | int ccp_register_aes_cmac_algs(struct list_head *head) |
350 | { |
351 | struct ccp_crypto_ahash_alg *ccp_alg; |
352 | struct ahash_alg *alg; |
353 | struct hash_alg_common *halg; |
354 | struct crypto_alg *base; |
355 | int ret; |
356 | |
357 | ccp_alg = kzalloc(size: sizeof(*ccp_alg), GFP_KERNEL); |
358 | if (!ccp_alg) |
359 | return -ENOMEM; |
360 | |
361 | INIT_LIST_HEAD(list: &ccp_alg->entry); |
362 | ccp_alg->mode = CCP_AES_MODE_CMAC; |
363 | |
364 | alg = &ccp_alg->alg; |
365 | alg->init = ccp_aes_cmac_init; |
366 | alg->update = ccp_aes_cmac_update; |
367 | alg->final = ccp_aes_cmac_final; |
368 | alg->finup = ccp_aes_cmac_finup; |
369 | alg->digest = ccp_aes_cmac_digest; |
370 | alg->export = ccp_aes_cmac_export; |
371 | alg->import = ccp_aes_cmac_import; |
372 | alg->setkey = ccp_aes_cmac_setkey; |
373 | |
374 | halg = &alg->halg; |
375 | halg->digestsize = AES_BLOCK_SIZE; |
376 | halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx); |
377 | |
378 | base = &halg->base; |
379 | snprintf(buf: base->cra_name, CRYPTO_MAX_ALG_NAME, fmt: "cmac(aes)" ); |
380 | snprintf(buf: base->cra_driver_name, CRYPTO_MAX_ALG_NAME, fmt: "cmac-aes-ccp" ); |
381 | base->cra_flags = CRYPTO_ALG_ASYNC | |
382 | CRYPTO_ALG_ALLOCATES_MEMORY | |
383 | CRYPTO_ALG_KERN_DRIVER_ONLY | |
384 | CRYPTO_ALG_NEED_FALLBACK; |
385 | base->cra_blocksize = AES_BLOCK_SIZE; |
386 | base->cra_ctxsize = sizeof(struct ccp_ctx) + crypto_dma_padding(); |
387 | base->cra_priority = CCP_CRA_PRIORITY; |
388 | base->cra_init = ccp_aes_cmac_cra_init; |
389 | base->cra_module = THIS_MODULE; |
390 | |
391 | ret = crypto_register_ahash(alg); |
392 | if (ret) { |
393 | pr_err("%s ahash algorithm registration error (%d)\n" , |
394 | base->cra_name, ret); |
395 | kfree(objp: ccp_alg); |
396 | return ret; |
397 | } |
398 | |
399 | list_add(new: &ccp_alg->entry, head); |
400 | |
401 | return 0; |
402 | } |
403 | |