1 /*
2 * AMD Cryptographic Coprocessor (CCP) SHA 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/hash.h>
20 #include <crypto/internal/hash.h>
21 #include <crypto/sha.h>
22 #include <crypto/scatterwalk.h>
23
24 #include "ccp-crypto.h"
25
ccp_sha_complete(struct crypto_async_request * async_req,int ret)26 static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
27 {
28 struct ahash_request *req = ahash_request_cast(async_req);
29 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
30 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
31 unsigned int digest_size = crypto_ahash_digestsize(tfm);
32
33 if (ret)
34 goto e_free;
35
36 if (rctx->hash_rem) {
37 /* Save remaining data to buffer */
38 unsigned int offset = rctx->nbytes - rctx->hash_rem;
39
40 scatterwalk_map_and_copy(rctx->buf, rctx->src,
41 offset, rctx->hash_rem, 0);
42 rctx->buf_count = rctx->hash_rem;
43 } else {
44 rctx->buf_count = 0;
45 }
46
47 /* Update result area if supplied */
48 if (req->result)
49 memcpy(req->result, rctx->ctx, digest_size);
50
51 e_free:
52 sg_free_table(&rctx->data_sg);
53
54 return ret;
55 }
56
ccp_do_sha_update(struct ahash_request * req,unsigned int nbytes,unsigned int final)57 static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
58 unsigned int final)
59 {
60 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
61 struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
62 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
63 struct scatterlist *sg;
64 unsigned int block_size =
65 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
66 unsigned int sg_count;
67 gfp_t gfp;
68 u64 len;
69 int ret;
70
71 len = (u64)rctx->buf_count + (u64)nbytes;
72
73 if (!final && (len <= block_size)) {
74 scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
75 0, nbytes, 0);
76 rctx->buf_count += nbytes;
77
78 return 0;
79 }
80
81 rctx->src = req->src;
82 rctx->nbytes = nbytes;
83
84 rctx->final = final;
85 rctx->hash_rem = final ? 0 : len & (block_size - 1);
86 rctx->hash_cnt = len - rctx->hash_rem;
87 if (!final && !rctx->hash_rem) {
88 /* CCP can't do zero length final, so keep some data around */
89 rctx->hash_cnt -= block_size;
90 rctx->hash_rem = block_size;
91 }
92
93 /* Initialize the context scatterlist */
94 sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx));
95
96 sg = NULL;
97 if (rctx->buf_count && nbytes) {
98 /* Build the data scatterlist table - allocate enough entries
99 * for both data pieces (buffer and input data)
100 */
101 gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
102 GFP_KERNEL : GFP_ATOMIC;
103 sg_count = sg_nents(req->src) + 1;
104 ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
105 if (ret)
106 return ret;
107
108 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
109 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
110 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
111 sg_mark_end(sg);
112
113 sg = rctx->data_sg.sgl;
114 } else if (rctx->buf_count) {
115 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
116
117 sg = &rctx->buf_sg;
118 } else if (nbytes) {
119 sg = req->src;
120 }
121
122 rctx->msg_bits += (rctx->hash_cnt << 3); /* Total in bits */
123
124 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
125 INIT_LIST_HEAD(&rctx->cmd.entry);
126 rctx->cmd.engine = CCP_ENGINE_SHA;
127 rctx->cmd.u.sha.type = rctx->type;
128 rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
129 rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
130 rctx->cmd.u.sha.src = sg;
131 rctx->cmd.u.sha.src_len = rctx->hash_cnt;
132 rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
133 &ctx->u.sha.opad_sg : NULL;
134 rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
135 ctx->u.sha.opad_count : 0;
136 rctx->cmd.u.sha.first = rctx->first;
137 rctx->cmd.u.sha.final = rctx->final;
138 rctx->cmd.u.sha.msg_bits = rctx->msg_bits;
139
140 rctx->first = 0;
141
142 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
143
144 return ret;
145 }
146
ccp_sha_init(struct ahash_request * req)147 static int ccp_sha_init(struct ahash_request *req)
148 {
149 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
150 struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
151 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
152 struct ccp_crypto_ahash_alg *alg =
153 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
154 unsigned int block_size =
155 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
156
157 memset(rctx, 0, sizeof(*rctx));
158
159 rctx->type = alg->type;
160 rctx->first = 1;
161
162 if (ctx->u.sha.key_len) {
163 /* Buffer the HMAC key for first update */
164 memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
165 rctx->buf_count = block_size;
166 }
167
168 return 0;
169 }
170
ccp_sha_update(struct ahash_request * req)171 static int ccp_sha_update(struct ahash_request *req)
172 {
173 return ccp_do_sha_update(req, req->nbytes, 0);
174 }
175
ccp_sha_final(struct ahash_request * req)176 static int ccp_sha_final(struct ahash_request *req)
177 {
178 return ccp_do_sha_update(req, 0, 1);
179 }
180
ccp_sha_finup(struct ahash_request * req)181 static int ccp_sha_finup(struct ahash_request *req)
182 {
183 return ccp_do_sha_update(req, req->nbytes, 1);
184 }
185
ccp_sha_digest(struct ahash_request * req)186 static int ccp_sha_digest(struct ahash_request *req)
187 {
188 int ret;
189
190 ret = ccp_sha_init(req);
191 if (ret)
192 return ret;
193
194 return ccp_sha_finup(req);
195 }
196
ccp_sha_export(struct ahash_request * req,void * out)197 static int ccp_sha_export(struct ahash_request *req, void *out)
198 {
199 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
200 struct ccp_sha_exp_ctx state;
201
202 /* Don't let anything leak to 'out' */
203 memset(&state, 0, sizeof(state));
204
205 state.type = rctx->type;
206 state.msg_bits = rctx->msg_bits;
207 state.first = rctx->first;
208 memcpy(state.ctx, rctx->ctx, sizeof(state.ctx));
209 state.buf_count = rctx->buf_count;
210 memcpy(state.buf, rctx->buf, sizeof(state.buf));
211
212 /* 'out' may not be aligned so memcpy from local variable */
213 memcpy(out, &state, sizeof(state));
214
215 return 0;
216 }
217
ccp_sha_import(struct ahash_request * req,const void * in)218 static int ccp_sha_import(struct ahash_request *req, const void *in)
219 {
220 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
221 struct ccp_sha_exp_ctx state;
222
223 /* 'in' may not be aligned so memcpy to local variable */
224 memcpy(&state, in, sizeof(state));
225
226 memset(rctx, 0, sizeof(*rctx));
227 rctx->type = state.type;
228 rctx->msg_bits = state.msg_bits;
229 rctx->first = state.first;
230 memcpy(rctx->ctx, state.ctx, sizeof(rctx->ctx));
231 rctx->buf_count = state.buf_count;
232 memcpy(rctx->buf, state.buf, sizeof(rctx->buf));
233
234 return 0;
235 }
236
ccp_sha_setkey(struct crypto_ahash * tfm,const u8 * key,unsigned int key_len)237 static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
238 unsigned int key_len)
239 {
240 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
241 struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
242
243 SHASH_DESC_ON_STACK(sdesc, shash);
244
245 unsigned int block_size = crypto_shash_blocksize(shash);
246 unsigned int digest_size = crypto_shash_digestsize(shash);
247 int i, ret;
248
249 /* Set to zero until complete */
250 ctx->u.sha.key_len = 0;
251
252 /* Clear key area to provide zero padding for keys smaller
253 * than the block size
254 */
255 memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key));
256
257 if (key_len > block_size) {
258 /* Must hash the input key */
259 sdesc->tfm = shash;
260 sdesc->flags = crypto_ahash_get_flags(tfm) &
261 CRYPTO_TFM_REQ_MAY_SLEEP;
262
263 ret = crypto_shash_digest(sdesc, key, key_len,
264 ctx->u.sha.key);
265 if (ret) {
266 crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
267 return -EINVAL;
268 }
269
270 key_len = digest_size;
271 } else {
272 memcpy(ctx->u.sha.key, key, key_len);
273 }
274
275 for (i = 0; i < block_size; i++) {
276 ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36;
277 ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
278 }
279
280 sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
281 ctx->u.sha.opad_count = block_size;
282
283 ctx->u.sha.key_len = key_len;
284
285 return 0;
286 }
287
ccp_sha_cra_init(struct crypto_tfm * tfm)288 static int ccp_sha_cra_init(struct crypto_tfm *tfm)
289 {
290 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
291 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
292
293 ctx->complete = ccp_sha_complete;
294 ctx->u.sha.key_len = 0;
295
296 crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));
297
298 return 0;
299 }
300
ccp_sha_cra_exit(struct crypto_tfm * tfm)301 static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
302 {
303 }
304
ccp_hmac_sha_cra_init(struct crypto_tfm * tfm)305 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
306 {
307 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
308 struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
309 struct crypto_shash *hmac_tfm;
310
311 hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
312 if (IS_ERR(hmac_tfm)) {
313 pr_warn("could not load driver %s need for HMAC support\n",
314 alg->child_alg);
315 return PTR_ERR(hmac_tfm);
316 }
317
318 ctx->u.sha.hmac_tfm = hmac_tfm;
319
320 return ccp_sha_cra_init(tfm);
321 }
322
ccp_hmac_sha_cra_exit(struct crypto_tfm * tfm)323 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
324 {
325 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
326
327 if (ctx->u.sha.hmac_tfm)
328 crypto_free_shash(ctx->u.sha.hmac_tfm);
329
330 ccp_sha_cra_exit(tfm);
331 }
332
333 struct ccp_sha_def {
334 const char *name;
335 const char *drv_name;
336 enum ccp_sha_type type;
337 u32 digest_size;
338 u32 block_size;
339 };
340
341 static struct ccp_sha_def sha_algs[] = {
342 {
343 .name = "sha1",
344 .drv_name = "sha1-ccp",
345 .type = CCP_SHA_TYPE_1,
346 .digest_size = SHA1_DIGEST_SIZE,
347 .block_size = SHA1_BLOCK_SIZE,
348 },
349 {
350 .name = "sha224",
351 .drv_name = "sha224-ccp",
352 .type = CCP_SHA_TYPE_224,
353 .digest_size = SHA224_DIGEST_SIZE,
354 .block_size = SHA224_BLOCK_SIZE,
355 },
356 {
357 .name = "sha256",
358 .drv_name = "sha256-ccp",
359 .type = CCP_SHA_TYPE_256,
360 .digest_size = SHA256_DIGEST_SIZE,
361 .block_size = SHA256_BLOCK_SIZE,
362 },
363 };
364
ccp_register_hmac_alg(struct list_head * head,const struct ccp_sha_def * def,const struct ccp_crypto_ahash_alg * base_alg)365 static int ccp_register_hmac_alg(struct list_head *head,
366 const struct ccp_sha_def *def,
367 const struct ccp_crypto_ahash_alg *base_alg)
368 {
369 struct ccp_crypto_ahash_alg *ccp_alg;
370 struct ahash_alg *alg;
371 struct hash_alg_common *halg;
372 struct crypto_alg *base;
373 int ret;
374
375 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
376 if (!ccp_alg)
377 return -ENOMEM;
378
379 /* Copy the base algorithm and only change what's necessary */
380 *ccp_alg = *base_alg;
381 INIT_LIST_HEAD(&ccp_alg->entry);
382
383 strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);
384
385 alg = &ccp_alg->alg;
386 alg->setkey = ccp_sha_setkey;
387
388 halg = &alg->halg;
389
390 base = &halg->base;
391 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
392 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
393 def->drv_name);
394 base->cra_init = ccp_hmac_sha_cra_init;
395 base->cra_exit = ccp_hmac_sha_cra_exit;
396
397 ret = crypto_register_ahash(alg);
398 if (ret) {
399 pr_err("%s ahash algorithm registration error (%d)\n",
400 base->cra_name, ret);
401 kfree(ccp_alg);
402 return ret;
403 }
404
405 list_add(&ccp_alg->entry, head);
406
407 return ret;
408 }
409
ccp_register_sha_alg(struct list_head * head,const struct ccp_sha_def * def)410 static int ccp_register_sha_alg(struct list_head *head,
411 const struct ccp_sha_def *def)
412 {
413 struct ccp_crypto_ahash_alg *ccp_alg;
414 struct ahash_alg *alg;
415 struct hash_alg_common *halg;
416 struct crypto_alg *base;
417 int ret;
418
419 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
420 if (!ccp_alg)
421 return -ENOMEM;
422
423 INIT_LIST_HEAD(&ccp_alg->entry);
424
425 ccp_alg->type = def->type;
426
427 alg = &ccp_alg->alg;
428 alg->init = ccp_sha_init;
429 alg->update = ccp_sha_update;
430 alg->final = ccp_sha_final;
431 alg->finup = ccp_sha_finup;
432 alg->digest = ccp_sha_digest;
433 alg->export = ccp_sha_export;
434 alg->import = ccp_sha_import;
435
436 halg = &alg->halg;
437 halg->digestsize = def->digest_size;
438 halg->statesize = sizeof(struct ccp_sha_exp_ctx);
439
440 base = &halg->base;
441 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
442 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
443 def->drv_name);
444 base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC |
445 CRYPTO_ALG_KERN_DRIVER_ONLY |
446 CRYPTO_ALG_NEED_FALLBACK;
447 base->cra_blocksize = def->block_size;
448 base->cra_ctxsize = sizeof(struct ccp_ctx);
449 base->cra_priority = CCP_CRA_PRIORITY;
450 base->cra_type = &crypto_ahash_type;
451 base->cra_init = ccp_sha_cra_init;
452 base->cra_exit = ccp_sha_cra_exit;
453 base->cra_module = THIS_MODULE;
454
455 ret = crypto_register_ahash(alg);
456 if (ret) {
457 pr_err("%s ahash algorithm registration error (%d)\n",
458 base->cra_name, ret);
459 kfree(ccp_alg);
460 return ret;
461 }
462
463 list_add(&ccp_alg->entry, head);
464
465 ret = ccp_register_hmac_alg(head, def, ccp_alg);
466
467 return ret;
468 }
469
ccp_register_sha_algs(struct list_head * head)470 int ccp_register_sha_algs(struct list_head *head)
471 {
472 int i, ret;
473
474 for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
475 ret = ccp_register_sha_alg(head, &sha_algs[i]);
476 if (ret)
477 return ret;
478 }
479
480 return 0;
481 }
482