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
ccp_aes_cmac_complete(struct crypto_async_request * async_req,int ret)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(async_req);
27 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
28 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(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(rctx->buf, rctx->src,
39 offset, rctx->hash_rem, 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
ccp_do_cmac_update(struct ahash_request * req,unsigned int nbytes,unsigned int final)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(tfm);
60 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
61 struct scatterlist *sg, *cmac_key_sg = NULL;
62 unsigned int block_size =
63 crypto_tfm_alg_blocksize(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(rctx->buf + rctx->buf_count, req->src,
79 0, nbytes, 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(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(&rctx->data_sg, &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(&rctx->data_sg, 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(&rctx->data_sg, &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(&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->base, &rctx->cmd);
174
175 return ret;
176
177 e_free:
178 sg_free_table(&rctx->data_sg);
179
180 return ret;
181 }
182
ccp_aes_cmac_init(struct ahash_request * req)183 static int ccp_aes_cmac_init(struct ahash_request *req)
184 {
185 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
186
187 memset(rctx, 0, sizeof(*rctx));
188
189 rctx->null_msg = 1;
190
191 return 0;
192 }
193
ccp_aes_cmac_update(struct ahash_request * req)194 static int ccp_aes_cmac_update(struct ahash_request *req)
195 {
196 return ccp_do_cmac_update(req, req->nbytes, 0);
197 }
198
ccp_aes_cmac_final(struct ahash_request * req)199 static int ccp_aes_cmac_final(struct ahash_request *req)
200 {
201 return ccp_do_cmac_update(req, 0, 1);
202 }
203
ccp_aes_cmac_finup(struct ahash_request * req)204 static int ccp_aes_cmac_finup(struct ahash_request *req)
205 {
206 return ccp_do_cmac_update(req, req->nbytes, 1);
207 }
208
ccp_aes_cmac_digest(struct ahash_request * req)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
ccp_aes_cmac_export(struct ahash_request * req,void * out)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(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
ccp_aes_cmac_import(struct ahash_request * req,const void * in)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(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
ccp_aes_cmac_setkey(struct crypto_ahash * tfm,const u8 * key,unsigned int key_len)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_tfm_ctx(crypto_ahash_tfm(tfm));
260 struct ccp_crypto_ahash_alg *alg =
261 ccp_crypto_ahash_alg(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(&aes, 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(&aes, ctx->u.aes.key, ctx->u.aes.key);
294 memzero_explicit(&aes, 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
ccp_aes_cmac_cra_init(struct crypto_tfm * tfm)335 static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm)
336 {
337 struct ccp_ctx *ctx = crypto_tfm_ctx(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(ahash, sizeof(struct ccp_aes_cmac_req_ctx));
344
345 return 0;
346 }
347
ccp_register_aes_cmac_algs(struct list_head * head)348 int ccp_register_aes_cmac_algs(struct list_head *head)
349 {
350 struct ccp_crypto_ahash_alg *ccp_alg;
351 struct ahash_alg *alg;
352 struct hash_alg_common *halg;
353 struct crypto_alg *base;
354 int ret;
355
356 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
357 if (!ccp_alg)
358 return -ENOMEM;
359
360 INIT_LIST_HEAD(&ccp_alg->entry);
361 ccp_alg->mode = CCP_AES_MODE_CMAC;
362
363 alg = &ccp_alg->alg;
364 alg->init = ccp_aes_cmac_init;
365 alg->update = ccp_aes_cmac_update;
366 alg->final = ccp_aes_cmac_final;
367 alg->finup = ccp_aes_cmac_finup;
368 alg->digest = ccp_aes_cmac_digest;
369 alg->export = ccp_aes_cmac_export;
370 alg->import = ccp_aes_cmac_import;
371 alg->setkey = ccp_aes_cmac_setkey;
372
373 halg = &alg->halg;
374 halg->digestsize = AES_BLOCK_SIZE;
375 halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx);
376
377 base = &halg->base;
378 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)");
379 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp");
380 base->cra_flags = CRYPTO_ALG_ASYNC |
381 CRYPTO_ALG_ALLOCATES_MEMORY |
382 CRYPTO_ALG_KERN_DRIVER_ONLY |
383 CRYPTO_ALG_NEED_FALLBACK;
384 base->cra_blocksize = AES_BLOCK_SIZE;
385 base->cra_ctxsize = sizeof(struct ccp_ctx);
386 base->cra_priority = CCP_CRA_PRIORITY;
387 base->cra_init = ccp_aes_cmac_cra_init;
388 base->cra_module = THIS_MODULE;
389
390 ret = crypto_register_ahash(alg);
391 if (ret) {
392 pr_err("%s ahash algorithm registration error (%d)\n",
393 base->cra_name, ret);
394 kfree(ccp_alg);
395 return ret;
396 }
397
398 list_add(&ccp_alg->entry, head);
399
400 return 0;
401 }
402