1/**
2 * AES CTR routines supporting the Power 7+ Nest Accelerators driver
3 *
4 * Copyright (C) 2011-2012 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/aes.h>
23#include <crypto/ctr.h>
24#include <crypto/algapi.h>
25#include <linux/module.h>
26#include <linux/types.h>
27#include <linux/crypto.h>
28#include <asm/vio.h>
29
30#include "nx_csbcpb.h"
31#include "nx.h"
32
33
34static int ctr_aes_nx_set_key(struct crypto_tfm *tfm,
35			      const u8          *in_key,
36			      unsigned int       key_len)
37{
38	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
39	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
40
41	nx_ctx_init(nx_ctx, HCOP_FC_AES);
42
43	switch (key_len) {
44	case AES_KEYSIZE_128:
45		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
46		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
47		break;
48	case AES_KEYSIZE_192:
49		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
50		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
51		break;
52	case AES_KEYSIZE_256:
53		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
54		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
55		break;
56	default:
57		return -EINVAL;
58	}
59
60	csbcpb->cpb.hdr.mode = NX_MODE_AES_CTR;
61	memcpy(csbcpb->cpb.aes_ctr.key, in_key, key_len);
62
63	return 0;
64}
65
66static int ctr3686_aes_nx_set_key(struct crypto_tfm *tfm,
67				  const u8          *in_key,
68				  unsigned int       key_len)
69{
70	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
71
72	if (key_len < CTR_RFC3686_NONCE_SIZE)
73		return -EINVAL;
74
75	memcpy(nx_ctx->priv.ctr.nonce,
76	       in_key + key_len - CTR_RFC3686_NONCE_SIZE,
77	       CTR_RFC3686_NONCE_SIZE);
78
79	key_len -= CTR_RFC3686_NONCE_SIZE;
80
81	return ctr_aes_nx_set_key(tfm, in_key, key_len);
82}
83
84static int ctr_aes_nx_crypt(struct blkcipher_desc *desc,
85			    struct scatterlist    *dst,
86			    struct scatterlist    *src,
87			    unsigned int           nbytes)
88{
89	struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
90	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
91	unsigned long irq_flags;
92	unsigned int processed = 0, to_process;
93	int rc;
94
95	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
96
97	do {
98		to_process = nbytes - processed;
99
100		rc = nx_build_sg_lists(nx_ctx, desc, dst, src, &to_process,
101				       processed, csbcpb->cpb.aes_ctr.iv);
102		if (rc)
103			goto out;
104
105		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
106			rc = -EINVAL;
107			goto out;
108		}
109
110		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
111				   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
112		if (rc)
113			goto out;
114
115		memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
116
117		atomic_inc(&(nx_ctx->stats->aes_ops));
118		atomic64_add(csbcpb->csb.processed_byte_count,
119			     &(nx_ctx->stats->aes_bytes));
120
121		processed += to_process;
122	} while (processed < nbytes);
123out:
124	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
125	return rc;
126}
127
128static int ctr3686_aes_nx_crypt(struct blkcipher_desc *desc,
129				struct scatterlist    *dst,
130				struct scatterlist    *src,
131				unsigned int           nbytes)
132{
133	struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
134	u8 iv[16];
135
136	memcpy(iv, nx_ctx->priv.ctr.nonce, CTR_RFC3686_IV_SIZE);
137	memcpy(iv + CTR_RFC3686_NONCE_SIZE,
138	       desc->info, CTR_RFC3686_IV_SIZE);
139	iv[12] = iv[13] = iv[14] = 0;
140	iv[15] = 1;
141
142	desc->info = iv;
143
144	return ctr_aes_nx_crypt(desc, dst, src, nbytes);
145}
146
147struct crypto_alg nx_ctr_aes_alg = {
148	.cra_name        = "ctr(aes)",
149	.cra_driver_name = "ctr-aes-nx",
150	.cra_priority    = 300,
151	.cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
152	.cra_blocksize   = 1,
153	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
154	.cra_type        = &crypto_blkcipher_type,
155	.cra_module      = THIS_MODULE,
156	.cra_init        = nx_crypto_ctx_aes_ctr_init,
157	.cra_exit        = nx_crypto_ctx_exit,
158	.cra_blkcipher = {
159		.min_keysize = AES_MIN_KEY_SIZE,
160		.max_keysize = AES_MAX_KEY_SIZE,
161		.ivsize      = AES_BLOCK_SIZE,
162		.setkey      = ctr_aes_nx_set_key,
163		.encrypt     = ctr_aes_nx_crypt,
164		.decrypt     = ctr_aes_nx_crypt,
165	}
166};
167
168struct crypto_alg nx_ctr3686_aes_alg = {
169	.cra_name        = "rfc3686(ctr(aes))",
170	.cra_driver_name = "rfc3686-ctr-aes-nx",
171	.cra_priority    = 300,
172	.cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
173	.cra_blocksize   = 1,
174	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
175	.cra_type        = &crypto_blkcipher_type,
176	.cra_module      = THIS_MODULE,
177	.cra_init        = nx_crypto_ctx_aes_ctr_init,
178	.cra_exit        = nx_crypto_ctx_exit,
179	.cra_blkcipher = {
180		.min_keysize = AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
181		.max_keysize = AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
182		.ivsize      = CTR_RFC3686_IV_SIZE,
183		.geniv       = "seqiv",
184		.setkey      = ctr3686_aes_nx_set_key,
185		.encrypt     = ctr3686_aes_nx_crypt,
186		.decrypt     = ctr3686_aes_nx_crypt,
187	}
188};
189