xref: /openbmc/linux/drivers/crypto/nx/nx-aes-ctr.c (revision 4419617e)
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 
22 static int ctr_aes_nx_set_key(struct crypto_tfm *tfm,
23 			      const u8          *in_key,
24 			      unsigned int       key_len)
25 {
26 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_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 
54 static int ctr3686_aes_nx_set_key(struct crypto_tfm *tfm,
55 				  const u8          *in_key,
56 				  unsigned int       key_len)
57 {
58 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_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 
72 static int ctr_aes_nx_crypt(struct blkcipher_desc *desc,
73 			    struct scatterlist    *dst,
74 			    struct scatterlist    *src,
75 			    unsigned int           nbytes)
76 {
77 	struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->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 = nbytes - processed;
87 
88 		rc = nx_build_sg_lists(nx_ctx, desc, dst, src, &to_process,
89 				       processed, csbcpb->cpb.aes_ctr.iv);
90 		if (rc)
91 			goto out;
92 
93 		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
94 			rc = -EINVAL;
95 			goto out;
96 		}
97 
98 		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
99 				   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
100 		if (rc)
101 			goto out;
102 
103 		memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
104 
105 		atomic_inc(&(nx_ctx->stats->aes_ops));
106 		atomic64_add(csbcpb->csb.processed_byte_count,
107 			     &(nx_ctx->stats->aes_bytes));
108 
109 		processed += to_process;
110 	} while (processed < nbytes);
111 out:
112 	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
113 	return rc;
114 }
115 
116 static int ctr3686_aes_nx_crypt(struct blkcipher_desc *desc,
117 				struct scatterlist    *dst,
118 				struct scatterlist    *src,
119 				unsigned int           nbytes)
120 {
121 	struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
122 	u8 iv[16];
123 
124 	memcpy(iv, nx_ctx->priv.ctr.nonce, CTR_RFC3686_IV_SIZE);
125 	memcpy(iv + CTR_RFC3686_NONCE_SIZE,
126 	       desc->info, CTR_RFC3686_IV_SIZE);
127 	iv[12] = iv[13] = iv[14] = 0;
128 	iv[15] = 1;
129 
130 	desc->info = iv;
131 
132 	return ctr_aes_nx_crypt(desc, dst, src, nbytes);
133 }
134 
135 struct crypto_alg nx_ctr3686_aes_alg = {
136 	.cra_name        = "rfc3686(ctr(aes))",
137 	.cra_driver_name = "rfc3686-ctr-aes-nx",
138 	.cra_priority    = 300,
139 	.cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
140 	.cra_blocksize   = 1,
141 	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
142 	.cra_type        = &crypto_blkcipher_type,
143 	.cra_module      = THIS_MODULE,
144 	.cra_init        = nx_crypto_ctx_aes_ctr_init,
145 	.cra_exit        = nx_crypto_ctx_exit,
146 	.cra_blkcipher = {
147 		.min_keysize = AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
148 		.max_keysize = AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
149 		.ivsize      = CTR_RFC3686_IV_SIZE,
150 		.setkey      = ctr3686_aes_nx_set_key,
151 		.encrypt     = ctr3686_aes_nx_crypt,
152 		.decrypt     = ctr3686_aes_nx_crypt,
153 	}
154 };
155