1 // SPDX-License-Identifier: GPL-2.0-or-later 1
2 /*
3 * PCBC: Propagating Cipher Block Chaining mod
4 *
5 * Copyright (C) 2006 Red Hat, Inc. All Rights
6 * Written by David Howells (dhowells@redhat.c
7 *
8 * Derived from cbc.c
9 * - Copyright (c) 2006 Herbert Xu <herbert@go
10 */
11
12 #include <crypto/algapi.h>
13 #include <crypto/internal/cipher.h>
14 #include <crypto/internal/skcipher.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19
20 static int crypto_pcbc_encrypt_segment(struct
21 struct
22 struct
23 {
24 int bsize = crypto_cipher_blocksize(tf
25 unsigned int nbytes = walk->nbytes;
26 u8 *src = walk->src.virt.addr;
27 u8 *dst = walk->dst.virt.addr;
28 u8 * const iv = walk->iv;
29
30 do {
31 crypto_xor(iv, src, bsize);
32 crypto_cipher_encrypt_one(tfm,
33 crypto_xor_cpy(iv, dst, src, b
34
35 src += bsize;
36 dst += bsize;
37 } while ((nbytes -= bsize) >= bsize);
38
39 return nbytes;
40 }
41
42 static int crypto_pcbc_encrypt_inplace(struct
43 struct
44 struct
45 {
46 int bsize = crypto_cipher_blocksize(tf
47 unsigned int nbytes = walk->nbytes;
48 u8 *src = walk->src.virt.addr;
49 u8 * const iv = walk->iv;
50 u8 tmpbuf[MAX_CIPHER_BLOCKSIZE];
51
52 do {
53 memcpy(tmpbuf, src, bsize);
54 crypto_xor(iv, src, bsize);
55 crypto_cipher_encrypt_one(tfm,
56 crypto_xor_cpy(iv, tmpbuf, src
57
58 src += bsize;
59 } while ((nbytes -= bsize) >= bsize);
60
61 return nbytes;
62 }
63
64 static int crypto_pcbc_encrypt(struct skcipher
65 {
66 struct crypto_skcipher *tfm = crypto_s
67 struct crypto_cipher *cipher = skciphe
68 struct skcipher_walk walk;
69 unsigned int nbytes;
70 int err;
71
72 err = skcipher_walk_virt(&walk, req, f
73
74 while (walk.nbytes) {
75 if (walk.src.virt.addr == walk
76 nbytes = crypto_pcbc_e
77
78 else
79 nbytes = crypto_pcbc_e
80
81 err = skcipher_walk_done(&walk
82 }
83
84 return err;
85 }
86
87 static int crypto_pcbc_decrypt_segment(struct
88 struct
89 struct
90 {
91 int bsize = crypto_cipher_blocksize(tf
92 unsigned int nbytes = walk->nbytes;
93 u8 *src = walk->src.virt.addr;
94 u8 *dst = walk->dst.virt.addr;
95 u8 * const iv = walk->iv;
96
97 do {
98 crypto_cipher_decrypt_one(tfm,
99 crypto_xor(dst, iv, bsize);
100 crypto_xor_cpy(iv, dst, src, b
101
102 src += bsize;
103 dst += bsize;
104 } while ((nbytes -= bsize) >= bsize);
105
106 return nbytes;
107 }
108
109 static int crypto_pcbc_decrypt_inplace(struct
110 struct
111 struct
112 {
113 int bsize = crypto_cipher_blocksize(tf
114 unsigned int nbytes = walk->nbytes;
115 u8 *src = walk->src.virt.addr;
116 u8 * const iv = walk->iv;
117 u8 tmpbuf[MAX_CIPHER_BLOCKSIZE] __alig
118
119 do {
120 memcpy(tmpbuf, src, bsize);
121 crypto_cipher_decrypt_one(tfm,
122 crypto_xor(src, iv, bsize);
123 crypto_xor_cpy(iv, src, tmpbuf
124
125 src += bsize;
126 } while ((nbytes -= bsize) >= bsize);
127
128 return nbytes;
129 }
130
131 static int crypto_pcbc_decrypt(struct skcipher
132 {
133 struct crypto_skcipher *tfm = crypto_s
134 struct crypto_cipher *cipher = skciphe
135 struct skcipher_walk walk;
136 unsigned int nbytes;
137 int err;
138
139 err = skcipher_walk_virt(&walk, req, f
140
141 while (walk.nbytes) {
142 if (walk.src.virt.addr == walk
143 nbytes = crypto_pcbc_d
144
145 else
146 nbytes = crypto_pcbc_d
147
148 err = skcipher_walk_done(&walk
149 }
150
151 return err;
152 }
153
154 static int crypto_pcbc_create(struct crypto_te
155 {
156 struct skcipher_instance *inst;
157 int err;
158
159 inst = skcipher_alloc_instance_simple(
160 if (IS_ERR(inst))
161 return PTR_ERR(inst);
162
163 inst->alg.encrypt = crypto_pcbc_encryp
164 inst->alg.decrypt = crypto_pcbc_decryp
165
166 err = skcipher_register_instance(tmpl,
167 if (err)
168 inst->free(inst);
169
170 return err;
171 }
172
173 static struct crypto_template crypto_pcbc_tmpl
174 .name = "pcbc",
175 .create = crypto_pcbc_create,
176 .module = THIS_MODULE,
177 };
178
179 static int __init crypto_pcbc_module_init(void
180 {
181 return crypto_register_template(&crypt
182 }
183
184 static void __exit crypto_pcbc_module_exit(voi
185 {
186 crypto_unregister_template(&crypto_pcb
187 }
188
189 subsys_initcall(crypto_pcbc_module_init);
190 module_exit(crypto_pcbc_module_exit);
191
192 MODULE_LICENSE("GPL");
193 MODULE_DESCRIPTION("PCBC block cipher mode of
194 MODULE_ALIAS_CRYPTO("pcbc");
195 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
196
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