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-rw-r--r--crypto/skcipher.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c
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1/*
2 * Symmetric key cipher operations.
3 *
4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
5 * multiple page boundaries by using temporary blocks. In user context,
6 * the kernel is given a chance to schedule us once per page.
7 *
8 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
12 * Software Foundation; either version 2 of the License, or (at your option)
13 * any later version.
14 *
15 */
16
17#include <crypto/internal/skcipher.h>
18#include <linux/bug.h>
19#include <linux/module.h>
20
21#include "internal.h"
22
23static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
24{
25 if (alg->cra_type == &crypto_blkcipher_type)
26 return sizeof(struct crypto_blkcipher *);
27
28 BUG_ON(alg->cra_type != &crypto_ablkcipher_type &&
29 alg->cra_type != &crypto_givcipher_type);
30
31 return sizeof(struct crypto_ablkcipher *);
32}
33
34static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
35 const u8 *key, unsigned int keylen)
36{
37 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
38 struct crypto_blkcipher *blkcipher = *ctx;
39 int err;
40
41 crypto_blkcipher_clear_flags(blkcipher, ~0);
42 crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
43 CRYPTO_TFM_REQ_MASK);
44 err = crypto_blkcipher_setkey(blkcipher, key, keylen);
45 crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
46 CRYPTO_TFM_RES_MASK);
47
48 return err;
49}
50
51static int skcipher_crypt_blkcipher(struct skcipher_request *req,
52 int (*crypt)(struct blkcipher_desc *,
53 struct scatterlist *,
54 struct scatterlist *,
55 unsigned int))
56{
57 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
58 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
59 struct blkcipher_desc desc = {
60 .tfm = *ctx,
61 .info = req->iv,
62 .flags = req->base.flags,
63 };
64
65
66 return crypt(&desc, req->dst, req->src, req->cryptlen);
67}
68
69static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
70{
71 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
72 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
73 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
74
75 return skcipher_crypt_blkcipher(req, alg->encrypt);
76}
77
78static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
79{
80 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
81 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
82 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
83
84 return skcipher_crypt_blkcipher(req, alg->decrypt);
85}
86
87static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
88{
89 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
90
91 crypto_free_blkcipher(*ctx);
92}
93
94int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
95{
96 struct crypto_alg *calg = tfm->__crt_alg;
97 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
98 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
99 struct crypto_blkcipher *blkcipher;
100 struct crypto_tfm *btfm;
101
102 if (!crypto_mod_get(calg))
103 return -EAGAIN;
104
105 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
106 CRYPTO_ALG_TYPE_MASK);
107 if (IS_ERR(btfm)) {
108 crypto_mod_put(calg);
109 return PTR_ERR(btfm);
110 }
111
112 blkcipher = __crypto_blkcipher_cast(btfm);
113 *ctx = blkcipher;
114 tfm->exit = crypto_exit_skcipher_ops_blkcipher;
115
116 skcipher->setkey = skcipher_setkey_blkcipher;
117 skcipher->encrypt = skcipher_encrypt_blkcipher;
118 skcipher->decrypt = skcipher_decrypt_blkcipher;
119
120 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
121
122 return 0;
123}
124
125static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
126 const u8 *key, unsigned int keylen)
127{
128 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
129 struct crypto_ablkcipher *ablkcipher = *ctx;
130 int err;
131
132 crypto_ablkcipher_clear_flags(ablkcipher, ~0);
133 crypto_ablkcipher_set_flags(ablkcipher,
134 crypto_skcipher_get_flags(tfm) &
135 CRYPTO_TFM_REQ_MASK);
136 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
137 crypto_skcipher_set_flags(tfm,
138 crypto_ablkcipher_get_flags(ablkcipher) &
139 CRYPTO_TFM_RES_MASK);
140
141 return err;
142}
143
144static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
145 int (*crypt)(struct ablkcipher_request *))
146{
147 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
148 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
149 struct ablkcipher_request *subreq = skcipher_request_ctx(req);
150
151 ablkcipher_request_set_tfm(subreq, *ctx);
152 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
153 req->base.complete, req->base.data);
154 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
155 req->iv);
156
157 return crypt(subreq);
158}
159
160static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
161{
162 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
163 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
164 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
165
166 return skcipher_crypt_ablkcipher(req, alg->encrypt);
167}
168
169static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
170{
171 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
172 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
173 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
174
175 return skcipher_crypt_ablkcipher(req, alg->decrypt);
176}
177
178static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
179{
180 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
181
182 crypto_free_ablkcipher(*ctx);
183}
184
185int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
186{
187 struct crypto_alg *calg = tfm->__crt_alg;
188 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
189 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
190 struct crypto_ablkcipher *ablkcipher;
191 struct crypto_tfm *abtfm;
192
193 if (!crypto_mod_get(calg))
194 return -EAGAIN;
195
196 abtfm = __crypto_alloc_tfm(calg, 0, 0);
197 if (IS_ERR(abtfm)) {
198 crypto_mod_put(calg);
199 return PTR_ERR(abtfm);
200 }
201
202 ablkcipher = __crypto_ablkcipher_cast(abtfm);
203 *ctx = ablkcipher;
204 tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
205
206 skcipher->setkey = skcipher_setkey_ablkcipher;
207 skcipher->encrypt = skcipher_encrypt_ablkcipher;
208 skcipher->decrypt = skcipher_decrypt_ablkcipher;
209
210 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
211 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
212 sizeof(struct ablkcipher_request);
213
214 return 0;
215}
216
217static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
218{
219 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
220 return crypto_init_skcipher_ops_blkcipher(tfm);
221
222 BUG_ON(tfm->__crt_alg->cra_type != &crypto_ablkcipher_type &&
223 tfm->__crt_alg->cra_type != &crypto_givcipher_type);
224
225 return crypto_init_skcipher_ops_ablkcipher(tfm);
226}
227
228static const struct crypto_type crypto_skcipher_type2 = {
229 .extsize = crypto_skcipher_extsize,
230 .init_tfm = crypto_skcipher_init_tfm,
231 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
232 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
233 .type = CRYPTO_ALG_TYPE_BLKCIPHER,
234 .tfmsize = offsetof(struct crypto_skcipher, base),
235};
236
237struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
238 u32 type, u32 mask)
239{
240 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
241}
242EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
243
244MODULE_LICENSE("GPL");
245MODULE_DESCRIPTION("Symmetric key cipher type");
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-01 17:46:59 -0400