1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Cryptographic API.
4 *
5 * Support for OMAP AES GCM HW acceleration.
6 *
7 * Copyright (c) 2016 Texas Instruments Incorporated
8 */
9
10#include <crypto/aes.h>
11#include <crypto/engine.h>
12#include <crypto/gcm.h>
13#include <crypto/internal/aead.h>
14#include <crypto/scatterwalk.h>
15#include <crypto/skcipher.h>
16#include <linux/errno.h>
17#include <linux/dma-mapping.h>
18#include <linux/dmaengine.h>
19#include <linux/interrupt.h>
20#include <linux/kernel.h>
21#include <linux/omap-dma.h>
22#include <linux/pm_runtime.h>
23#include <linux/scatterlist.h>
24#include <linux/string.h>
25
26#include "omap-crypto.h"
27#include "omap-aes.h"
28
29static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd,
30 struct aead_request *req);
31
32static void omap_aes_gcm_finish_req(struct omap_aes_dev *dd, int ret)
33{
34 struct aead_request *req = dd->aead_req;
35
36 dd->in_sg = NULL;
37 dd->out_sg = NULL;
38
39 crypto_finalize_aead_request(engine: dd->engine, req, err: ret);
40
41 pm_runtime_mark_last_busy(dev: dd->dev);
42 pm_runtime_put_autosuspend(dev: dd->dev);
43}
44
45static void omap_aes_gcm_done_task(struct omap_aes_dev *dd)
46{
47 u8 *tag;
48 int alen, clen, i, ret = 0, nsg;
49 struct omap_aes_reqctx *rctx;
50
51 alen = ALIGN(dd->assoc_len, AES_BLOCK_SIZE);
52 clen = ALIGN(dd->total, AES_BLOCK_SIZE);
53 rctx = aead_request_ctx(req: dd->aead_req);
54
55 nsg = !!(dd->assoc_len && dd->total);
56
57 dma_sync_sg_for_device(dev: dd->dev, sg: dd->out_sg, nelems: dd->out_sg_len,
58 dir: DMA_FROM_DEVICE);
59 dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
60 dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len, DMA_FROM_DEVICE);
61 omap_aes_crypt_dma_stop(dd);
62
63 omap_crypto_cleanup(sg: dd->out_sg, orig: dd->orig_out,
64 offset: dd->aead_req->assoclen, len: dd->total,
65 FLAGS_OUT_DATA_ST_SHIFT, flags: dd->flags);
66
67 if (dd->flags & FLAGS_ENCRYPT)
68 scatterwalk_map_and_copy(buf: rctx->auth_tag,
69 sg: dd->aead_req->dst,
70 start: dd->total + dd->aead_req->assoclen,
71 nbytes: dd->authsize, out: 1);
72
73 omap_crypto_cleanup(sg: &dd->in_sgl[0], NULL, offset: 0, len: alen,
74 FLAGS_ASSOC_DATA_ST_SHIFT, flags: dd->flags);
75
76 omap_crypto_cleanup(sg: &dd->in_sgl[nsg], NULL, offset: 0, len: clen,
77 FLAGS_IN_DATA_ST_SHIFT, flags: dd->flags);
78
79 if (!(dd->flags & FLAGS_ENCRYPT)) {
80 tag = (u8 *)rctx->auth_tag;
81 for (i = 0; i < dd->authsize; i++) {
82 if (tag[i]) {
83 ret = -EBADMSG;
84 }
85 }
86 }
87
88 omap_aes_gcm_finish_req(dd, ret);
89}
90
91static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
92 struct aead_request *req)
93{
94 int alen, clen, cryptlen, assoclen, ret;
95 struct crypto_aead *aead = crypto_aead_reqtfm(req);
96 unsigned int authlen = crypto_aead_authsize(tfm: aead);
97 struct scatterlist *tmp, sg_arr[2];
98 int nsg;
99 u16 flags;
100
101 assoclen = req->assoclen;
102 cryptlen = req->cryptlen;
103
104 if (dd->flags & FLAGS_RFC4106_GCM)
105 assoclen -= 8;
106
107 if (!(dd->flags & FLAGS_ENCRYPT))
108 cryptlen -= authlen;
109
110 alen = ALIGN(assoclen, AES_BLOCK_SIZE);
111 clen = ALIGN(cryptlen, AES_BLOCK_SIZE);
112
113 nsg = !!(assoclen && cryptlen);
114
115 omap_aes_clear_copy_flags(dd);
116
117 sg_init_table(dd->in_sgl, nsg + 1);
118 if (assoclen) {
119 tmp = req->src;
120 ret = omap_crypto_align_sg(sg: &tmp, total: assoclen,
121 AES_BLOCK_SIZE, new_sg: dd->in_sgl,
122 OMAP_CRYPTO_COPY_DATA |
123 OMAP_CRYPTO_ZERO_BUF |
124 OMAP_CRYPTO_FORCE_SINGLE_ENTRY,
125 FLAGS_ASSOC_DATA_ST_SHIFT,
126 dd_flags: &dd->flags);
127 if (ret)
128 return ret;
129 }
130
131 if (cryptlen) {
132 tmp = scatterwalk_ffwd(dst: sg_arr, src: req->src, len: req->assoclen);
133
134 if (nsg)
135 sg_unmark_end(sg: dd->in_sgl);
136
137 ret = omap_crypto_align_sg(sg: &tmp, total: cryptlen,
138 AES_BLOCK_SIZE, new_sg: &dd->in_sgl[nsg],
139 OMAP_CRYPTO_COPY_DATA |
140 OMAP_CRYPTO_ZERO_BUF |
141 OMAP_CRYPTO_FORCE_SINGLE_ENTRY,
142 FLAGS_IN_DATA_ST_SHIFT,
143 dd_flags: &dd->flags);
144 if (ret)
145 return ret;
146 }
147
148 dd->in_sg = dd->in_sgl;
149 dd->total = cryptlen;
150 dd->assoc_len = assoclen;
151 dd->authsize = authlen;
152
153 dd->out_sg = req->dst;
154 dd->orig_out = req->dst;
155
156 dd->out_sg = scatterwalk_ffwd(dst: sg_arr, src: req->dst, len: req->assoclen);
157
158 flags = 0;
159 if (req->src == req->dst || dd->out_sg == sg_arr)
160 flags |= OMAP_CRYPTO_FORCE_COPY;
161
162 if (cryptlen) {
163 ret = omap_crypto_align_sg(sg: &dd->out_sg, total: cryptlen,
164 AES_BLOCK_SIZE, new_sg: &dd->out_sgl,
165 flags,
166 FLAGS_OUT_DATA_ST_SHIFT, dd_flags: &dd->flags);
167 if (ret)
168 return ret;
169 }
170
171 dd->in_sg_len = sg_nents_for_len(sg: dd->in_sg, len: alen + clen);
172 dd->out_sg_len = sg_nents_for_len(sg: dd->out_sg, len: clen);
173
174 return 0;
175}
176
177static int do_encrypt_iv(struct aead_request *req, u32 *tag, u32 *iv)
178{
179 struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm: crypto_aead_reqtfm(req));
180
181 aes_encrypt(ctx: &ctx->actx, out: (u8 *)tag, in: (u8 *)iv);
182 return 0;
183}
184
185void omap_aes_gcm_dma_out_callback(void *data)
186{
187 struct omap_aes_dev *dd = data;
188 struct omap_aes_reqctx *rctx;
189 int i, val;
190 u32 *auth_tag, tag[4];
191
192 if (!(dd->flags & FLAGS_ENCRYPT))
193 scatterwalk_map_and_copy(buf: tag, sg: dd->aead_req->src,
194 start: dd->total + dd->aead_req->assoclen,
195 nbytes: dd->authsize, out: 0);
196
197 rctx = aead_request_ctx(req: dd->aead_req);
198 auth_tag = (u32 *)rctx->auth_tag;
199 for (i = 0; i < 4; i++) {
200 val = omap_aes_read(dd, AES_REG_TAG_N(dd, i));
201 auth_tag[i] = val ^ auth_tag[i];
202 if (!(dd->flags & FLAGS_ENCRYPT))
203 auth_tag[i] = auth_tag[i] ^ tag[i];
204 }
205
206 omap_aes_gcm_done_task(dd);
207}
208
209static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd,
210 struct aead_request *req)
211{
212 if (req)
213 return crypto_transfer_aead_request_to_engine(engine: dd->engine, req);
214
215 return 0;
216}
217
218static int omap_aes_gcm_prepare_req(struct aead_request *req,
219 struct omap_aes_dev *dd)
220{
221 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
222 struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm: crypto_aead_reqtfm(req));
223 int err;
224
225 dd->aead_req = req;
226
227 rctx->mode &= FLAGS_MODE_MASK;
228 dd->flags = (dd->flags & ~FLAGS_MODE_MASK) | rctx->mode;
229
230 err = omap_aes_gcm_copy_buffers(dd, req);
231 if (err)
232 return err;
233
234 dd->ctx = &ctx->octx;
235
236 return omap_aes_write_ctrl(dd);
237}
238
239static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode)
240{
241 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
242 struct crypto_aead *aead = crypto_aead_reqtfm(req);
243 unsigned int authlen = crypto_aead_authsize(tfm: aead);
244 struct omap_aes_dev *dd;
245 __be32 counter = cpu_to_be32(1);
246 int err, assoclen;
247
248 memset(rctx->auth_tag, 0, sizeof(rctx->auth_tag));
249 memcpy(rctx->iv + GCM_AES_IV_SIZE, &counter, 4);
250
251 err = do_encrypt_iv(req, tag: (u32 *)rctx->auth_tag, iv: (u32 *)rctx->iv);
252 if (err)
253 return err;
254
255 if (mode & FLAGS_RFC4106_GCM)
256 assoclen = req->assoclen - 8;
257 else
258 assoclen = req->assoclen;
259 if (assoclen + req->cryptlen == 0) {
260 scatterwalk_map_and_copy(buf: rctx->auth_tag, sg: req->dst, start: 0, nbytes: authlen,
261 out: 1);
262 return 0;
263 }
264
265 dd = omap_aes_find_dev(rctx);
266 if (!dd)
267 return -ENODEV;
268 rctx->mode = mode;
269
270 return omap_aes_gcm_handle_queue(dd, req);
271}
272
273int omap_aes_gcm_encrypt(struct aead_request *req)
274{
275 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
276
277 memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
278 return omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM);
279}
280
281int omap_aes_gcm_decrypt(struct aead_request *req)
282{
283 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
284
285 memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
286 return omap_aes_gcm_crypt(req, FLAGS_GCM);
287}
288
289int omap_aes_4106gcm_encrypt(struct aead_request *req)
290{
291 struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm: crypto_aead_reqtfm(req));
292 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
293
294 memcpy(rctx->iv, ctx->octx.nonce, 4);
295 memcpy(rctx->iv + 4, req->iv, 8);
296 return crypto_ipsec_check_assoclen(assoclen: req->assoclen) ?:
297 omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM |
298 FLAGS_RFC4106_GCM);
299}
300
301int omap_aes_4106gcm_decrypt(struct aead_request *req)
302{
303 struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm: crypto_aead_reqtfm(req));
304 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
305
306 memcpy(rctx->iv, ctx->octx.nonce, 4);
307 memcpy(rctx->iv + 4, req->iv, 8);
308 return crypto_ipsec_check_assoclen(assoclen: req->assoclen) ?:
309 omap_aes_gcm_crypt(req, FLAGS_GCM | FLAGS_RFC4106_GCM);
310}
311
312int omap_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
313 unsigned int keylen)
314{
315 struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
316 int ret;
317
318 ret = aes_expandkey(ctx: &ctx->actx, in_key: key, key_len: keylen);
319 if (ret)
320 return ret;
321
322 memcpy(ctx->octx.key, key, keylen);
323 ctx->octx.keylen = keylen;
324
325 return 0;
326}
327
328int omap_aes_4106gcm_setkey(struct crypto_aead *tfm, const u8 *key,
329 unsigned int keylen)
330{
331 struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
332 int ret;
333
334 if (keylen < 4)
335 return -EINVAL;
336 keylen -= 4;
337
338 ret = aes_expandkey(ctx: &ctx->actx, in_key: key, key_len: keylen);
339 if (ret)
340 return ret;
341
342 memcpy(ctx->octx.key, key, keylen);
343 memcpy(ctx->octx.nonce, key + keylen, 4);
344 ctx->octx.keylen = keylen;
345
346 return 0;
347}
348
349int omap_aes_gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
350{
351 return crypto_gcm_check_authsize(authsize);
352}
353
354int omap_aes_4106gcm_setauthsize(struct crypto_aead *parent,
355 unsigned int authsize)
356{
357 return crypto_rfc4106_check_authsize(authsize);
358}
359
360int omap_aes_gcm_crypt_req(struct crypto_engine *engine, void *areq)
361{
362 struct aead_request *req = container_of(areq, struct aead_request,
363 base);
364 struct omap_aes_reqctx *rctx = aead_request_ctx(req);
365 struct omap_aes_dev *dd = rctx->dd;
366 int ret;
367
368 if (!dd)
369 return -ENODEV;
370
371 ret = omap_aes_gcm_prepare_req(req, dd);
372 if (ret)
373 return ret;
374
375 if (dd->in_sg_len)
376 ret = omap_aes_crypt_dma_start(dd);
377 else
378 omap_aes_gcm_dma_out_callback(data: dd);
379
380 return ret;
381}
382
383int omap_aes_gcm_cra_init(struct crypto_aead *tfm)
384{
385 crypto_aead_set_reqsize(aead: tfm, reqsize: sizeof(struct omap_aes_reqctx));
386
387 return 0;
388}
389

source code of linux/drivers/crypto/omap-aes-gcm.c