1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AES CTR routines supporting the Power 7+ Nest Accelerators driver
4 *
5 * Copyright (C) 2011-2012 International Business Machines Inc.
6 *
7 * Author: Kent Yoder <yoder1@us.ibm.com>
8 */
9
10#include <crypto/aes.h>
11#include <crypto/ctr.h>
12#include <crypto/algapi.h>
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/crypto.h>
16#include <asm/vio.h>
17
18#include "nx_csbcpb.h"
19#include "nx.h"
20
21
22static int ctr_aes_nx_set_key(struct crypto_skcipher *tfm,
23			      const u8               *in_key,
24			      unsigned int            key_len)
25{
26	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
27	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
28
29	nx_ctx_init(nx_ctx, HCOP_FC_AES);
30
31	switch (key_len) {
32	case AES_KEYSIZE_128:
33		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
34		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
35		break;
36	case AES_KEYSIZE_192:
37		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
38		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
39		break;
40	case AES_KEYSIZE_256:
41		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
42		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
43		break;
44	default:
45		return -EINVAL;
46	}
47
48	csbcpb->cpb.hdr.mode = NX_MODE_AES_CTR;
49	memcpy(csbcpb->cpb.aes_ctr.key, in_key, key_len);
50
51	return 0;
52}
53
54static int ctr3686_aes_nx_set_key(struct crypto_skcipher *tfm,
55				  const u8               *in_key,
56				  unsigned int            key_len)
57{
58	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
59
60	if (key_len < CTR_RFC3686_NONCE_SIZE)
61		return -EINVAL;
62
63	memcpy(nx_ctx->priv.ctr.nonce,
64	       in_key + key_len - CTR_RFC3686_NONCE_SIZE,
65	       CTR_RFC3686_NONCE_SIZE);
66
67	key_len -= CTR_RFC3686_NONCE_SIZE;
68
69	return ctr_aes_nx_set_key(tfm, in_key, key_len);
70}
71
72static int ctr_aes_nx_crypt(struct skcipher_request *req, u8 *iv)
73{
74	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
75	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
76	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
77	unsigned long irq_flags;
78	unsigned int processed = 0, to_process;
79	int rc;
80
81	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
82
83	do {
84		to_process = req->cryptlen - processed;
85
86		rc = nx_build_sg_lists(nx_ctx, iv, req->dst, req->src,
87				       &to_process, processed,
88				       csbcpb->cpb.aes_ctr.iv);
89		if (rc)
90			goto out;
91
92		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
93			rc = -EINVAL;
94			goto out;
95		}
96
97		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
98				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
99		if (rc)
100			goto out;
101
102		memcpy(iv, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
103
104		atomic_inc(&(nx_ctx->stats->aes_ops));
105		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
106			     &(nx_ctx->stats->aes_bytes));
107
108		processed += to_process;
109	} while (processed < req->cryptlen);
110out:
111	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
112	return rc;
113}
114
115static int ctr3686_aes_nx_crypt(struct skcipher_request *req)
116{
117	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
118	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
119	u8 iv[16];
120
121	memcpy(iv, nx_ctx->priv.ctr.nonce, CTR_RFC3686_NONCE_SIZE);
122	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
123	iv[12] = iv[13] = iv[14] = 0;
124	iv[15] = 1;
125
126	return ctr_aes_nx_crypt(req, iv);
127}
128
129struct skcipher_alg nx_ctr3686_aes_alg = {
130	.base.cra_name		= "rfc3686(ctr(aes))",
131	.base.cra_driver_name	= "rfc3686-ctr-aes-nx",
132	.base.cra_priority	= 300,
133	.base.cra_blocksize	= 1,
134	.base.cra_ctxsize	= sizeof(struct nx_crypto_ctx),
135	.base.cra_module	= THIS_MODULE,
136	.init			= nx_crypto_ctx_aes_ctr_init,
137	.exit			= nx_crypto_ctx_skcipher_exit,
138	.min_keysize		= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
139	.max_keysize		= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
140	.ivsize			= CTR_RFC3686_IV_SIZE,
141	.setkey			= ctr3686_aes_nx_set_key,
142	.encrypt		= ctr3686_aes_nx_crypt,
143	.decrypt		= ctr3686_aes_nx_crypt,
144	.chunksize		= AES_BLOCK_SIZE,
145};
146