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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Public Key Encryption
4 *
5 * Copyright (c) 2015, Intel Corporation
6 * Authors: Tadeusz Struk <[email protected]>
7 */
8#include <crypto/internal/akcipher.h>
9#include <linux/cryptouser.h>
10#include <linux/errno.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/scatterlist.h>
14#include <linux/seq_file.h>
15#include <linux/slab.h>
16#include <linux/string.h>
17#include <net/netlink.h>
18
19#include "internal.h"
20
21#define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e
22
23struct crypto_akcipher_sync_data {
24 struct crypto_akcipher *tfm;
25 const void *src;
26 void *dst;
27 unsigned int slen;
28 unsigned int dlen;
29
30 struct akcipher_request *req;
31 struct crypto_wait cwait;
32 struct scatterlist sg;
33 u8 *buf;
34};
35
36static int __maybe_unused crypto_akcipher_report(
37 struct sk_buff *skb, struct crypto_alg *alg)
38{
39 struct crypto_report_akcipher rakcipher = {
40 .type = "akcipher",
41 };
42
43 return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
44 sizeof(rakcipher), &rakcipher);
45}
46
47static void __maybe_unused crypto_akcipher_show(struct seq_file *m,
48 struct crypto_alg *alg)
49{
50 seq_puts(m, "type : akcipher\n");
51}
52
53static void crypto_akcipher_exit_tfm(struct crypto_tfm *tfm)
54{
55 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm);
56 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher);
57
58 alg->exit(akcipher);
59}
60
61static int crypto_akcipher_init_tfm(struct crypto_tfm *tfm)
62{
63 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm);
64 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher);
65
66 if (alg->exit)
67 akcipher->base.exit = crypto_akcipher_exit_tfm;
68
69 if (alg->init)
70 return alg->init(akcipher);
71
72 return 0;
73}
74
75static void crypto_akcipher_free_instance(struct crypto_instance *inst)
76{
77 struct akcipher_instance *akcipher = akcipher_instance(inst);
78
79 akcipher->free(akcipher);
80}
81
82static const struct crypto_type crypto_akcipher_type = {
83 .extsize = crypto_alg_extsize,
84 .init_tfm = crypto_akcipher_init_tfm,
85 .free = crypto_akcipher_free_instance,
86#ifdef CONFIG_PROC_FS
87 .show = crypto_akcipher_show,
88#endif
89#if IS_ENABLED(CONFIG_CRYPTO_USER)
90 .report = crypto_akcipher_report,
91#endif
92 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
93 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
94 .type = CRYPTO_ALG_TYPE_AKCIPHER,
95 .tfmsize = offsetof(struct crypto_akcipher, base),
96 .algsize = offsetof(struct akcipher_alg, base),
97};
98
99int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn,
100 struct crypto_instance *inst,
101 const char *name, u32 type, u32 mask)
102{
103 spawn->base.frontend = &crypto_akcipher_type;
104 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
105}
106EXPORT_SYMBOL_GPL(crypto_grab_akcipher);
107
108struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
109 u32 mask)
110{
111 return crypto_alloc_tfm(alg_name, &crypto_akcipher_type, type, mask);
112}
113EXPORT_SYMBOL_GPL(crypto_alloc_akcipher);
114
115static void akcipher_prepare_alg(struct akcipher_alg *alg)
116{
117 struct crypto_alg *base = &alg->base;
118
119 base->cra_type = &crypto_akcipher_type;
120 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
121 base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER;
122}
123
124static int akcipher_default_op(struct akcipher_request *req)
125{
126 return -ENOSYS;
127}
128
129static int akcipher_default_set_key(struct crypto_akcipher *tfm,
130 const void *key, unsigned int keylen)
131{
132 return -ENOSYS;
133}
134
135int crypto_register_akcipher(struct akcipher_alg *alg)
136{
137 struct crypto_alg *base = &alg->base;
138
139 if (!alg->encrypt)
140 alg->encrypt = akcipher_default_op;
141 if (!alg->decrypt)
142 alg->decrypt = akcipher_default_op;
143 if (!alg->set_priv_key)
144 alg->set_priv_key = akcipher_default_set_key;
145
146 akcipher_prepare_alg(alg);
147 return crypto_register_alg(base);
148}
149EXPORT_SYMBOL_GPL(crypto_register_akcipher);
150
151void crypto_unregister_akcipher(struct akcipher_alg *alg)
152{
153 crypto_unregister_alg(&alg->base);
154}
155EXPORT_SYMBOL_GPL(crypto_unregister_akcipher);
156
157int akcipher_register_instance(struct crypto_template *tmpl,
158 struct akcipher_instance *inst)
159{
160 if (WARN_ON(!inst->free))
161 return -EINVAL;
162 akcipher_prepare_alg(&inst->alg);
163 return crypto_register_instance(tmpl, akcipher_crypto_instance(inst));
164}
165EXPORT_SYMBOL_GPL(akcipher_register_instance);
166
167static int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data)
168{
169 unsigned int reqsize = crypto_akcipher_reqsize(data->tfm);
170 struct akcipher_request *req;
171 struct scatterlist *sg;
172 unsigned int mlen;
173 unsigned int len;
174 u8 *buf;
175
176 mlen = max(data->slen, data->dlen);
177
178 len = sizeof(*req) + reqsize + mlen;
179 if (len < mlen)
180 return -EOVERFLOW;
181
182 req = kzalloc(len, GFP_KERNEL);
183 if (!req)
184 return -ENOMEM;
185
186 data->req = req;
187 akcipher_request_set_tfm(req, data->tfm);
188
189 buf = (u8 *)(req + 1) + reqsize;
190 data->buf = buf;
191 memcpy(buf, data->src, data->slen);
192
193 sg = &data->sg;
194 sg_init_one(sg, buf, mlen);
195 akcipher_request_set_crypt(req, sg, sg, data->slen, data->dlen);
196
197 crypto_init_wait(&data->cwait);
198 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
199 crypto_req_done, &data->cwait);
200
201 return 0;
202}
203
204static int crypto_akcipher_sync_post(struct crypto_akcipher_sync_data *data,
205 int err)
206{
207 err = crypto_wait_req(err, &data->cwait);
208 memcpy(data->dst, data->buf, data->dlen);
209 data->dlen = data->req->dst_len;
210 kfree_sensitive(data->req);
211 return err;
212}
213
214int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm,
215 const void *src, unsigned int slen,
216 void *dst, unsigned int dlen)
217{
218 struct crypto_akcipher_sync_data data = {
219 .tfm = tfm,
220 .src = src,
221 .dst = dst,
222 .slen = slen,
223 .dlen = dlen,
224 };
225
226 return crypto_akcipher_sync_prep(&data) ?:
227 crypto_akcipher_sync_post(&data,
228 crypto_akcipher_encrypt(data.req));
229}
230EXPORT_SYMBOL_GPL(crypto_akcipher_sync_encrypt);
231
232int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm,
233 const void *src, unsigned int slen,
234 void *dst, unsigned int dlen)
235{
236 struct crypto_akcipher_sync_data data = {
237 .tfm = tfm,
238 .src = src,
239 .dst = dst,
240 .slen = slen,
241 .dlen = dlen,
242 };
243
244 return crypto_akcipher_sync_prep(&data) ?:
245 crypto_akcipher_sync_post(&data,
246 crypto_akcipher_decrypt(data.req)) ?:
247 data.dlen;
248}
249EXPORT_SYMBOL_GPL(crypto_akcipher_sync_decrypt);
250
251MODULE_LICENSE("GPL");
252MODULE_DESCRIPTION("Generic public key cipher type");