xref: /linux/drivers/crypto/nx/nx-aes-ctr.c (revision 762f99f4f3cb41a775b5157dd761217beba65873)
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 
ctr_aes_nx_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)22 static 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 
ctr3686_aes_nx_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)54 static 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 
ctr_aes_nx_crypt(struct skcipher_request * req,u8 * iv)72 static 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);
110 out:
111 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
112 	return rc;
113 }
114 
ctr3686_aes_nx_crypt(struct skcipher_request * req)115 static 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 
129 struct 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