summaryrefslogtreecommitdiffstats
path: root/drivers/crypto/nx/nx-aes-gcm.c
blob: 6cca6c392b00f34fa65ad4663b1725bd7b3842fe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
/**
 * AES GCM routines supporting the Power 7+ Nest Accelerators driver
 *
 * Copyright (C) 2012 International Business Machines Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 only.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Author: Kent Yoder <yoder1@us.ibm.com>
 */

#include <crypto/internal/aead.h>
#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/crypto.h>
#include <asm/vio.h>

#include "nx_csbcpb.h"
#include "nx.h"


static int gcm_aes_nx_set_key(struct crypto_aead *tfm,
			      const u8           *in_key,
			      unsigned int        key_len)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
	struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;

	nx_ctx_init(nx_ctx, HCOP_FC_AES);

	switch (key_len) {
	case AES_KEYSIZE_128:
		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
		NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
		break;
	case AES_KEYSIZE_192:
		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
		NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192);
		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
		break;
	case AES_KEYSIZE_256:
		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
		NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_256);
		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
		break;
	default:
		return -EINVAL;
	}

	csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
	memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len);

	csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA;
	memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len);

	return 0;
}

static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm,
				  const u8           *in_key,
				  unsigned int        key_len)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
	char *nonce = nx_ctx->priv.gcm.nonce;
	int rc;

	if (key_len < 4)
		return -EINVAL;

	key_len -= 4;

	rc = gcm_aes_nx_set_key(tfm, in_key, key_len);
	if (rc)
		goto out;

	memcpy(nonce, in_key + key_len, 4);
out:
	return rc;
}

static int gcm_aes_nx_setauthsize(struct crypto_aead *tfm,
				  unsigned int authsize)
{
	if (authsize > crypto_aead_alg(tfm)->maxauthsize)
		return -EINVAL;

	crypto_aead_crt(tfm)->authsize = authsize;

	return 0;
}

static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm,
				      unsigned int authsize)
{
	switch (authsize) {
	case 8:
	case 12:
	case 16:
		break;
	default:
		return -EINVAL;
	}

	crypto_aead_crt(tfm)->authsize = authsize;

	return 0;
}

static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
		  struct aead_request   *req,
		  u8                    *out)
{
	struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
	int rc = -EINVAL;
	struct scatter_walk walk;
	struct nx_sg *nx_sg = nx_ctx->in_sg;

	if (req->assoclen > nx_ctx->ap->databytelen)
		goto out;

	if (req->assoclen <= AES_BLOCK_SIZE) {
		scatterwalk_start(&walk, req->assoc);
		scatterwalk_copychunks(out, &walk, req->assoclen,
				       SCATTERWALK_FROM_SG);
		scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0);

		rc = 0;
		goto out;
	}

	nx_sg = nx_walk_and_build(nx_sg, nx_ctx->ap->sglen, req->assoc, 0,
				  req->assoclen);
	nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg) * sizeof(struct nx_sg);

	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,
			   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
	if (rc)
		goto out;

	atomic_inc(&(nx_ctx->stats->aes_ops));
	atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes));

	memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE);
out:
	return rc;
}

static int gcm_aes_nx_crypt(struct aead_request *req, int enc)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
	struct blkcipher_desc desc;
	unsigned int nbytes = req->cryptlen;
	int rc = -EINVAL;

	if (nbytes > nx_ctx->ap->databytelen)
		goto out;

	desc.info = nx_ctx->priv.gcm.iv;
	/* initialize the counter */
	*(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;

	/* For scenarios where the input message is zero length, AES CTR mode
	 * may be used. Set the source data to be a single block (16B) of all
	 * zeros, and set the input IV value to be the same as the GMAC IV
	 * value. - nx_wb 4.8.1.3 */
	if (nbytes == 0) {
		char src[AES_BLOCK_SIZE] = {};
		struct scatterlist sg;

		desc.tfm = crypto_alloc_blkcipher("ctr(aes)", 0, 0);
		if (IS_ERR(desc.tfm)) {
			rc = -ENOMEM;
			goto out;
		}

		crypto_blkcipher_setkey(desc.tfm, csbcpb->cpb.aes_gcm.key,
			NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_128 ? 16 :
			NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_192 ? 24 : 32);

		sg_init_one(&sg, src, AES_BLOCK_SIZE);
		if (enc)
			crypto_blkcipher_encrypt_iv(&desc, req->dst, &sg,
						    AES_BLOCK_SIZE);
		else
			crypto_blkcipher_decrypt_iv(&desc, req->dst, &sg,
						    AES_BLOCK_SIZE);
		crypto_free_blkcipher(desc.tfm);

		rc = 0;
		goto out;
	}

	desc.tfm = (struct crypto_blkcipher *)req->base.tfm;

	csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8;

	if (req->assoclen) {
		rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad);
		if (rc)
			goto out;
	}

	if (enc)
		NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
	else
		nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));

	csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;

	rc = nx_build_sg_lists(nx_ctx, &desc, req->dst, req->src, nbytes,
			       csbcpb->cpb.aes_gcm.iv_or_cnt);
	if (rc)
		goto out;

	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
			   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
	if (rc)
		goto out;

	atomic_inc(&(nx_ctx->stats->aes_ops));
	atomic64_add(csbcpb->csb.processed_byte_count,
		     &(nx_ctx->stats->aes_bytes));

	if (enc) {
		/* copy out the auth tag */
		scatterwalk_map_and_copy(csbcpb->cpb.aes_gcm.out_pat_or_mac,
				 req->dst, nbytes,
				 crypto_aead_authsize(crypto_aead_reqtfm(req)),
				 SCATTERWALK_TO_SG);
	} else if (req->assoclen) {
		u8 *itag = nx_ctx->priv.gcm.iauth_tag;
		u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;

		scatterwalk_map_and_copy(itag, req->dst, nbytes,
				 crypto_aead_authsize(crypto_aead_reqtfm(req)),
				 SCATTERWALK_FROM_SG);
		rc = memcmp(itag, otag,
			    crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
		     -EBADMSG : 0;
	}
out:
	return rc;
}

static int gcm_aes_nx_encrypt(struct aead_request *req)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
	char *iv = nx_ctx->priv.gcm.iv;

	memcpy(iv, req->iv, 12);

	return gcm_aes_nx_crypt(req, 1);
}

static int gcm_aes_nx_decrypt(struct aead_request *req)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
	char *iv = nx_ctx->priv.gcm.iv;

	memcpy(iv, req->iv, 12);

	return gcm_aes_nx_crypt(req, 0);
}

static int gcm4106_aes_nx_encrypt(struct aead_request *req)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
	char *iv = nx_ctx->priv.gcm.iv;
	char *nonce = nx_ctx->priv.gcm.nonce;

	memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
	memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);

	return gcm_aes_nx_crypt(req, 1);
}

static int gcm4106_aes_nx_decrypt(struct aead_request *req)
{
	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
	char *iv = nx_ctx->priv.gcm.iv;
	char *nonce = nx_ctx->priv.gcm.nonce;

	memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
	memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);

	return gcm_aes_nx_crypt(req, 0);
}

/* tell the block cipher walk routines that this is a stream cipher by
 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
 * during encrypt/decrypt doesn't solve this problem, because it calls
 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
 * but instead uses this tfm->blocksize. */
struct crypto_alg nx_gcm_aes_alg = {
	.cra_name        = "gcm(aes)",
	.cra_driver_name = "gcm-aes-nx",
	.cra_priority    = 300,
	.cra_flags       = CRYPTO_ALG_TYPE_AEAD,
	.cra_blocksize   = 1,
	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
	.cra_type        = &crypto_aead_type,
	.cra_module      = THIS_MODULE,
	.cra_init        = nx_crypto_ctx_aes_gcm_init,
	.cra_exit        = nx_crypto_ctx_exit,
	.cra_aead = {
		.ivsize      = AES_BLOCK_SIZE,
		.maxauthsize = AES_BLOCK_SIZE,
		.setkey      = gcm_aes_nx_set_key,
		.setauthsize = gcm_aes_nx_setauthsize,
		.encrypt     = gcm_aes_nx_encrypt,
		.decrypt     = gcm_aes_nx_decrypt,
	}
};

struct crypto_alg nx_gcm4106_aes_alg = {
	.cra_name        = "rfc4106(gcm(aes))",
	.cra_driver_name = "rfc4106-gcm-aes-nx",
	.cra_priority    = 300,
	.cra_flags       = CRYPTO_ALG_TYPE_AEAD,
	.cra_blocksize   = 1,
	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
	.cra_type        = &crypto_nivaead_type,
	.cra_module      = THIS_MODULE,
	.cra_init        = nx_crypto_ctx_aes_gcm_init,
	.cra_exit        = nx_crypto_ctx_exit,
	.cra_aead = {
		.ivsize      = 8,
		.maxauthsize = AES_BLOCK_SIZE,
		.geniv       = "seqiv",
		.setkey      = gcm4106_aes_nx_set_key,
		.setauthsize = gcm4106_aes_nx_setauthsize,
		.encrypt     = gcm4106_aes_nx_encrypt,
		.decrypt     = gcm4106_aes_nx_decrypt,
	}
};
OpenPOWER on IntegriCloud