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authorKent Yoder <key@linux.vnet.ibm.com>2012-05-14 07:05:23 -0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-05-16 01:05:42 -0400
commita00bd6e60a341d6d21f9dfed89a8a7cf82383389 (patch)
treece6129c627296d7b92cd16ea2a2f82fd3a7a742e /drivers/crypto/nx
parent856d673476e31c1dfe568777956036637d53902d (diff)
powerpc/crypto: AES-CCM mode routines for nx encryption
These routines add support for AES in CCM mode on the Power7+ CPU's in-Nest accelerator driver. Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'drivers/crypto/nx')
-rw-r--r--drivers/crypto/nx/nx-aes-ccm.c468
1 files changed, 468 insertions, 0 deletions
diff --git a/drivers/crypto/nx/nx-aes-ccm.c b/drivers/crypto/nx/nx-aes-ccm.c
new file mode 100644
index 000000000000..7aeac678b9c0
--- /dev/null
+++ b/drivers/crypto/nx/nx-aes-ccm.c
@@ -0,0 +1,468 @@
1/**
2 * AES CCM routines supporting the Power 7+ Nest Accelerators driver
3 *
4 * Copyright (C) 2012 International Business Machines Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 only.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 *
19 * Author: Kent Yoder <yoder1@us.ibm.com>
20 */
21
22#include <crypto/internal/aead.h>
23#include <crypto/aes.h>
24#include <crypto/algapi.h>
25#include <crypto/scatterwalk.h>
26#include <linux/module.h>
27#include <linux/types.h>
28#include <linux/crypto.h>
29#include <asm/vio.h>
30
31#include "nx_csbcpb.h"
32#include "nx.h"
33
34
35static int ccm_aes_nx_set_key(struct crypto_aead *tfm,
36 const u8 *in_key,
37 unsigned int key_len)
38{
39 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
40 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
41 struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
42
43 nx_ctx_init(nx_ctx, HCOP_FC_AES);
44
45 switch (key_len) {
46 case AES_KEYSIZE_128:
47 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
48 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
49 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
50 break;
51 default:
52 return -EINVAL;
53 }
54
55 csbcpb->cpb.hdr.mode = NX_MODE_AES_CCM;
56 memcpy(csbcpb->cpb.aes_ccm.key, in_key, key_len);
57
58 csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_CCA;
59 memcpy(csbcpb_aead->cpb.aes_cca.key, in_key, key_len);
60
61 return 0;
62
63}
64
65static int ccm4309_aes_nx_set_key(struct crypto_aead *tfm,
66 const u8 *in_key,
67 unsigned int key_len)
68{
69 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
70
71 if (key_len < 3)
72 return -EINVAL;
73
74 key_len -= 3;
75
76 memcpy(nx_ctx->priv.ccm.nonce, in_key + key_len, 3);
77
78 return ccm_aes_nx_set_key(tfm, in_key, key_len);
79}
80
81static int ccm_aes_nx_setauthsize(struct crypto_aead *tfm,
82 unsigned int authsize)
83{
84 switch (authsize) {
85 case 4:
86 case 6:
87 case 8:
88 case 10:
89 case 12:
90 case 14:
91 case 16:
92 break;
93 default:
94 return -EINVAL;
95 }
96
97 crypto_aead_crt(tfm)->authsize = authsize;
98
99 return 0;
100}
101
102static int ccm4309_aes_nx_setauthsize(struct crypto_aead *tfm,
103 unsigned int authsize)
104{
105 switch (authsize) {
106 case 8:
107 case 12:
108 case 16:
109 break;
110 default:
111 return -EINVAL;
112 }
113
114 crypto_aead_crt(tfm)->authsize = authsize;
115
116 return 0;
117}
118
119/* taken from crypto/ccm.c */
120static int set_msg_len(u8 *block, unsigned int msglen, int csize)
121{
122 __be32 data;
123
124 memset(block, 0, csize);
125 block += csize;
126
127 if (csize >= 4)
128 csize = 4;
129 else if (msglen > (unsigned int)(1 << (8 * csize)))
130 return -EOVERFLOW;
131
132 data = cpu_to_be32(msglen);
133 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
134
135 return 0;
136}
137
138/* taken from crypto/ccm.c */
139static inline int crypto_ccm_check_iv(const u8 *iv)
140{
141 /* 2 <= L <= 8, so 1 <= L' <= 7. */
142 if (1 > iv[0] || iv[0] > 7)
143 return -EINVAL;
144
145 return 0;
146}
147
148/* based on code from crypto/ccm.c */
149static int generate_b0(u8 *iv, unsigned int assoclen, unsigned int authsize,
150 unsigned int cryptlen, u8 *b0)
151{
152 unsigned int l, lp, m = authsize;
153 int rc;
154
155 memcpy(b0, iv, 16);
156
157 lp = b0[0];
158 l = lp + 1;
159
160 /* set m, bits 3-5 */
161 *b0 |= (8 * ((m - 2) / 2));
162
163 /* set adata, bit 6, if associated data is used */
164 if (assoclen)
165 *b0 |= 64;
166
167 rc = set_msg_len(b0 + 16 - l, cryptlen, l);
168
169 return rc;
170}
171
172static int generate_pat(u8 *iv,
173 struct aead_request *req,
174 struct nx_crypto_ctx *nx_ctx,
175 unsigned int authsize,
176 unsigned int nbytes,
177 u8 *out)
178{
179 struct nx_sg *nx_insg = nx_ctx->in_sg;
180 struct nx_sg *nx_outsg = nx_ctx->out_sg;
181 unsigned int iauth_len = 0;
182 struct vio_pfo_op *op = NULL;
183 u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL;
184 int rc;
185
186 /* zero the ctr value */
187 memset(iv + 15 - iv[0], 0, iv[0] + 1);
188
189 if (!req->assoclen) {
190 b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
191 } else if (req->assoclen <= 14) {
192 /* if associated data is 14 bytes or less, we do 1 GCM
193 * operation on 2 AES blocks, B0 (stored in the csbcpb) and B1,
194 * which is fed in through the source buffers here */
195 b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
196 b1 = nx_ctx->priv.ccm.iauth_tag;
197 iauth_len = req->assoclen;
198
199 nx_insg = nx_build_sg_list(nx_insg, b1, 16, nx_ctx->ap->sglen);
200 nx_outsg = nx_build_sg_list(nx_outsg, tmp, 16,
201 nx_ctx->ap->sglen);
202
203 /* inlen should be negative, indicating to phyp that its a
204 * pointer to an sg list */
205 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) *
206 sizeof(struct nx_sg);
207 nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) *
208 sizeof(struct nx_sg);
209
210 NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT;
211 NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE;
212
213 op = &nx_ctx->op;
214 result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac;
215 } else if (req->assoclen <= 65280) {
216 /* if associated data is less than (2^16 - 2^8), we construct
217 * B1 differently and feed in the associated data to a CCA
218 * operation */
219 b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
220 b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
221 iauth_len = 14;
222
223 /* remaining assoc data must have scatterlist built for it */
224 nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen,
225 req->assoc, iauth_len,
226 req->assoclen - iauth_len);
227 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) *
228 sizeof(struct nx_sg);
229
230 op = &nx_ctx->op_aead;
231 result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0;
232 } else {
233 /* if associated data is less than (2^32), we construct B1
234 * differently yet again and feed in the associated data to a
235 * CCA operation */
236 pr_err("associated data len is %u bytes (returning -EINVAL)\n",
237 req->assoclen);
238 rc = -EINVAL;
239 }
240
241 rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0);
242 if (rc)
243 goto done;
244
245 if (b1) {
246 memset(b1, 0, 16);
247 *(u16 *)b1 = (u16)req->assoclen;
248
249 scatterwalk_map_and_copy(b1 + 2, req->assoc, 0,
250 iauth_len, SCATTERWALK_FROM_SG);
251
252 rc = nx_hcall_sync(nx_ctx, op,
253 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
254 if (rc)
255 goto done;
256
257 atomic_inc(&(nx_ctx->stats->aes_ops));
258 atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes));
259
260 memcpy(out, result, AES_BLOCK_SIZE);
261 }
262done:
263 return rc;
264}
265
266static int ccm_nx_decrypt(struct aead_request *req,
267 struct blkcipher_desc *desc)
268{
269 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
270 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
271 unsigned int nbytes = req->cryptlen;
272 unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
273 struct nx_ccm_priv *priv = &nx_ctx->priv.ccm;
274 int rc = -1;
275
276 if (nbytes > nx_ctx->ap->databytelen)
277 return -EINVAL;
278
279 nbytes -= authsize;
280
281 /* copy out the auth tag to compare with later */
282 scatterwalk_map_and_copy(priv->oauth_tag,
283 req->src, nbytes, authsize,
284 SCATTERWALK_FROM_SG);
285
286 rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes,
287 csbcpb->cpb.aes_ccm.in_pat_or_b0);
288 if (rc)
289 goto out;
290
291 rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes,
292 csbcpb->cpb.aes_ccm.iv_or_ctr);
293 if (rc)
294 goto out;
295
296 NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
297 NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_INTERMEDIATE;
298
299 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
300 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
301 if (rc)
302 goto out;
303
304 atomic_inc(&(nx_ctx->stats->aes_ops));
305 atomic64_add(csbcpb->csb.processed_byte_count,
306 &(nx_ctx->stats->aes_bytes));
307
308 rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag,
309 authsize) ? -EBADMSG : 0;
310out:
311 return rc;
312}
313
314static int ccm_nx_encrypt(struct aead_request *req,
315 struct blkcipher_desc *desc)
316{
317 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
318 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
319 unsigned int nbytes = req->cryptlen;
320 unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
321 int rc = -1;
322
323 if (nbytes > nx_ctx->ap->databytelen)
324 return -EINVAL;
325
326 rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes,
327 csbcpb->cpb.aes_ccm.in_pat_or_b0);
328 if (rc)
329 goto out;
330
331 rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes,
332 csbcpb->cpb.aes_ccm.iv_or_ctr);
333 if (rc)
334 goto out;
335
336 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
337 NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
338
339 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
340 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
341 if (rc)
342 goto out;
343
344 atomic_inc(&(nx_ctx->stats->aes_ops));
345 atomic64_add(csbcpb->csb.processed_byte_count,
346 &(nx_ctx->stats->aes_bytes));
347
348 /* copy out the auth tag */
349 scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac,
350 req->dst, nbytes, authsize,
351 SCATTERWALK_TO_SG);
352out:
353 return rc;
354}
355
356static int ccm4309_aes_nx_encrypt(struct aead_request *req)
357{
358 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
359 struct blkcipher_desc desc;
360 u8 *iv = nx_ctx->priv.ccm.iv;
361
362 iv[0] = 3;
363 memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3);
364 memcpy(iv + 4, req->iv, 8);
365
366 desc.info = iv;
367 desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
368
369 return ccm_nx_encrypt(req, &desc);
370}
371
372static int ccm_aes_nx_encrypt(struct aead_request *req)
373{
374 struct blkcipher_desc desc;
375 int rc;
376
377 desc.info = req->iv;
378 desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
379
380 rc = crypto_ccm_check_iv(desc.info);
381 if (rc)
382 return rc;
383
384 return ccm_nx_encrypt(req, &desc);
385}
386
387static int ccm4309_aes_nx_decrypt(struct aead_request *req)
388{
389 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
390 struct blkcipher_desc desc;
391 u8 *iv = nx_ctx->priv.ccm.iv;
392
393 iv[0] = 3;
394 memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3);
395 memcpy(iv + 4, req->iv, 8);
396
397 desc.info = iv;
398 desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
399
400 return ccm_nx_decrypt(req, &desc);
401}
402
403static int ccm_aes_nx_decrypt(struct aead_request *req)
404{
405 struct blkcipher_desc desc;
406 int rc;
407
408 desc.info = req->iv;
409 desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
410
411 rc = crypto_ccm_check_iv(desc.info);
412 if (rc)
413 return rc;
414
415 return ccm_nx_decrypt(req, &desc);
416}
417
418/* tell the block cipher walk routines that this is a stream cipher by
419 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
420 * during encrypt/decrypt doesn't solve this problem, because it calls
421 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
422 * but instead uses this tfm->blocksize. */
423struct crypto_alg nx_ccm_aes_alg = {
424 .cra_name = "ccm(aes)",
425 .cra_driver_name = "ccm-aes-nx",
426 .cra_priority = 300,
427 .cra_flags = CRYPTO_ALG_TYPE_AEAD |
428 CRYPTO_ALG_NEED_FALLBACK,
429 .cra_blocksize = 1,
430 .cra_ctxsize = sizeof(struct nx_crypto_ctx),
431 .cra_type = &crypto_aead_type,
432 .cra_module = THIS_MODULE,
433 .cra_list = LIST_HEAD_INIT(nx_ccm_aes_alg.cra_list),
434 .cra_init = nx_crypto_ctx_aes_ccm_init,
435 .cra_exit = nx_crypto_ctx_exit,
436 .cra_aead = {
437 .ivsize = AES_BLOCK_SIZE,
438 .maxauthsize = AES_BLOCK_SIZE,
439 .setkey = ccm_aes_nx_set_key,
440 .setauthsize = ccm_aes_nx_setauthsize,
441 .encrypt = ccm_aes_nx_encrypt,
442 .decrypt = ccm_aes_nx_decrypt,
443 }
444};
445
446struct crypto_alg nx_ccm4309_aes_alg = {
447 .cra_name = "rfc4309(ccm(aes))",
448 .cra_driver_name = "rfc4309-ccm-aes-nx",
449 .cra_priority = 300,
450 .cra_flags = CRYPTO_ALG_TYPE_AEAD |
451 CRYPTO_ALG_NEED_FALLBACK,
452 .cra_blocksize = 1,
453 .cra_ctxsize = sizeof(struct nx_crypto_ctx),
454 .cra_type = &crypto_nivaead_type,
455 .cra_module = THIS_MODULE,
456 .cra_list = LIST_HEAD_INIT(nx_ccm4309_aes_alg.cra_list),
457 .cra_init = nx_crypto_ctx_aes_ccm_init,
458 .cra_exit = nx_crypto_ctx_exit,
459 .cra_aead = {
460 .ivsize = 8,
461 .maxauthsize = AES_BLOCK_SIZE,
462 .setkey = ccm4309_aes_nx_set_key,
463 .setauthsize = ccm4309_aes_nx_setauthsize,
464 .encrypt = ccm4309_aes_nx_encrypt,
465 .decrypt = ccm4309_aes_nx_decrypt,
466 .geniv = "seqiv",
467 }
468};