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/internal/skcipher.h>
13 #include <linux/err.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/spinlock.h>
17 #include <linux/string.h>
18 #include <asm/vio.h>
19 
20 #include "nx_csbcpb.h"
21 #include "nx.h"
22 
23 
24 static int ctr_aes_nx_set_key(struct crypto_skcipher *tfm,
25 			      const u8               *in_key,
26 			      unsigned int            key_len)
27 {
28 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
29 	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
30 
31 	nx_ctx_init(nx_ctx, HCOP_FC_AES);
32 
33 	switch (key_len) {
34 	case AES_KEYSIZE_128:
35 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
36 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
37 		break;
38 	case AES_KEYSIZE_192:
39 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
40 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
41 		break;
42 	case AES_KEYSIZE_256:
43 		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
44 		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
45 		break;
46 	default:
47 		return -EINVAL;
48 	}
49 
50 	csbcpb->cpb.hdr.mode = NX_MODE_AES_CTR;
51 	memcpy(csbcpb->cpb.aes_ctr.key, in_key, key_len);
52 
53 	return 0;
54 }
55 
56 static int ctr3686_aes_nx_set_key(struct crypto_skcipher *tfm,
57 				  const u8               *in_key,
58 				  unsigned int            key_len)
59 {
60 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
61 
62 	if (key_len < CTR_RFC3686_NONCE_SIZE)
63 		return -EINVAL;
64 
65 	memcpy(nx_ctx->priv.ctr.nonce,
66 	       in_key + key_len - CTR_RFC3686_NONCE_SIZE,
67 	       CTR_RFC3686_NONCE_SIZE);
68 
69 	key_len -= CTR_RFC3686_NONCE_SIZE;
70 
71 	return ctr_aes_nx_set_key(tfm, in_key, key_len);
72 }
73 
74 static int ctr_aes_nx_crypt(struct skcipher_request *req, u8 *iv)
75 {
76 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
77 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
78 	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
79 	unsigned long irq_flags;
80 	unsigned int processed = 0, to_process;
81 	int rc;
82 
83 	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
84 
85 	do {
86 		to_process = req->cryptlen - processed;
87 
88 		rc = nx_build_sg_lists(nx_ctx, iv, req->dst, req->src,
89 				       &to_process, processed,
90 				       csbcpb->cpb.aes_ctr.iv);
91 		if (rc)
92 			goto out;
93 
94 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
95 			rc = -EINVAL;
96 			goto out;
97 		}
98 
99 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
100 				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
101 		if (rc)
102 			goto out;
103 
104 		memcpy(iv, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
105 
106 		atomic_inc(&(nx_ctx->stats->aes_ops));
107 		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
108 			     &(nx_ctx->stats->aes_bytes));
109 
110 		processed += to_process;
111 	} while (processed < req->cryptlen);
112 out:
113 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
114 	return rc;
115 }
116 
117 static int ctr3686_aes_nx_crypt(struct skcipher_request *req)
118 {
119 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
120 	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
121 	u8 iv[16];
122 
123 	memcpy(iv, nx_ctx->priv.ctr.nonce, CTR_RFC3686_NONCE_SIZE);
124 	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
125 	iv[12] = iv[13] = iv[14] = 0;
126 	iv[15] = 1;
127 
128 	return ctr_aes_nx_crypt(req, iv);
129 }
130 
131 struct skcipher_alg nx_ctr3686_aes_alg = {
132 	.base.cra_name		= "rfc3686(ctr(aes))",
133 	.base.cra_driver_name	= "rfc3686-ctr-aes-nx",
134 	.base.cra_priority	= 300,
135 	.base.cra_blocksize	= 1,
136 	.base.cra_ctxsize	= sizeof(struct nx_crypto_ctx),
137 	.base.cra_module	= THIS_MODULE,
138 	.init			= nx_crypto_ctx_aes_ctr_init,
139 	.exit			= nx_crypto_ctx_skcipher_exit,
140 	.min_keysize		= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
141 	.max_keysize		= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
142 	.ivsize			= CTR_RFC3686_IV_SIZE,
143 	.setkey			= ctr3686_aes_nx_set_key,
144 	.encrypt		= ctr3686_aes_nx_crypt,
145 	.decrypt		= ctr3686_aes_nx_crypt,
146 	.chunksize		= AES_BLOCK_SIZE,
147 };
148