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 <tadeusz.struk@intel.com>
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
23 static int __maybe_unused crypto_akcipher_report(
24 struct sk_buff *skb, struct crypto_alg *alg)
25 {
26 struct crypto_report_akcipher rakcipher;
27
28 memset(&rakcipher, 0, sizeof(rakcipher));
29
30 strscpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
31
32 return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
33 sizeof(rakcipher), &rakcipher);
34 }
35
36 static void crypto_akcipher_show(struct seq_file *m, struct crypto_alg *alg)
37 __maybe_unused;
38
39 static void crypto_akcipher_show(struct seq_file *m, struct crypto_alg *alg)
40 {
41 seq_puts(m, "type : akcipher\n");
42 }
43
44 static void crypto_akcipher_exit_tfm(struct crypto_tfm *tfm)
45 {
46 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm);
47 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher);
48
49 alg->exit(akcipher);
50 }
51
52 static int crypto_akcipher_init_tfm(struct crypto_tfm *tfm)
53 {
54 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm);
55 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher);
56
57 if (alg->exit)
58 akcipher->base.exit = crypto_akcipher_exit_tfm;
59
60 if (alg->init)
61 return alg->init(akcipher);
62
63 return 0;
64 }
65
66 static void crypto_akcipher_free_instance(struct crypto_instance *inst)
67 {
68 struct akcipher_instance *akcipher = akcipher_instance(inst);
69
70 akcipher->free(akcipher);
71 }
72
73 static const struct crypto_type crypto_akcipher_type = {
74 .extsize = crypto_alg_extsize,
75 .init_tfm = crypto_akcipher_init_tfm,
76 .free = crypto_akcipher_free_instance,
77 #ifdef CONFIG_PROC_FS
78 .show = crypto_akcipher_show,
79 #endif
80 #if IS_ENABLED(CONFIG_CRYPTO_USER)
81 .report = crypto_akcipher_report,
82 #endif
83 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
84 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
85 .type = CRYPTO_ALG_TYPE_AKCIPHER,
86 .tfmsize = offsetof(struct crypto_akcipher, base),
87 };
88
89 int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn,
90 struct crypto_instance *inst,
91 const char *name, u32 type, u32 mask)
92 {
93 spawn->base.frontend = &crypto_akcipher_type;
94 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
95 }
96 EXPORT_SYMBOL_GPL(crypto_grab_akcipher);
97
98 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
99 u32 mask)
100 {
101 return crypto_alloc_tfm(alg_name, &crypto_akcipher_type, type, mask);
102 }
103 EXPORT_SYMBOL_GPL(crypto_alloc_akcipher);
104
105 static void akcipher_prepare_alg(struct akcipher_alg *alg)
106 {
107 struct crypto_alg *base = &alg->base;
108
109 base->cra_type = &crypto_akcipher_type;
110 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
111 base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER;
112 }
113
114 static int akcipher_default_op(struct akcipher_request *req)
115 {
116 return -ENOSYS;
117 }
118
119 static int akcipher_default_set_key(struct crypto_akcipher *tfm,
120 const void *key, unsigned int keylen)
121 {
122 return -ENOSYS;
123 }
124
125 int crypto_register_akcipher(struct akcipher_alg *alg)
126 {
127 struct crypto_alg *base = &alg->base;
128
129 if (!alg->sign)
130 alg->sign = akcipher_default_op;
131 if (!alg->verify)
132 alg->verify = akcipher_default_op;
133 if (!alg->encrypt)
134 alg->encrypt = akcipher_default_op;
135 if (!alg->decrypt)
136 alg->decrypt = akcipher_default_op;
137 if (!alg->set_priv_key)
138 alg->set_priv_key = akcipher_default_set_key;
139
140 akcipher_prepare_alg(alg);
141 return crypto_register_alg(base);
142 }
143 EXPORT_SYMBOL_GPL(crypto_register_akcipher);
144
145 void crypto_unregister_akcipher(struct akcipher_alg *alg)
146 {
147 crypto_unregister_alg(&alg->base);
148 }
149 EXPORT_SYMBOL_GPL(crypto_unregister_akcipher);
150
151 int akcipher_register_instance(struct crypto_template *tmpl,
152 struct akcipher_instance *inst)
153 {
154 if (WARN_ON(!inst->free))
155 return -EINVAL;
156 akcipher_prepare_alg(&inst->alg);
157 return crypto_register_instance(tmpl, akcipher_crypto_instance(inst));
158 }
159 EXPORT_SYMBOL_GPL(akcipher_register_instance);
160
161 int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data)
162 {
163 unsigned int reqsize = crypto_akcipher_reqsize(data->tfm);
164 struct akcipher_request *req;
165 struct scatterlist *sg;
166 unsigned int mlen;
167 unsigned int len;
168 u8 *buf;
169
170 if (data->dst)
171 mlen = max(data->slen, data->dlen);
172 else
173 mlen = data->slen + data->dlen;
174
175 len = sizeof(*req) + reqsize + mlen;
176 if (len < mlen)
177 return -EOVERFLOW;
178
179 req = kzalloc(len, GFP_KERNEL);
180 if (!req)
181 return -ENOMEM;
182
183 data->req = req;
184 akcipher_request_set_tfm(req, data->tfm);
185
186 buf = (u8 *)(req + 1) + reqsize;
187 data->buf = buf;
188 memcpy(buf, data->src, data->slen);
189
190 sg = &data->sg;
191 sg_init_one(sg, buf, mlen);
192 akcipher_request_set_crypt(req, sg, data->dst ? sg : NULL,
193 data->slen, data->dlen);
194
195 crypto_init_wait(&data->cwait);
196 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
197 crypto_req_done, &data->cwait);
198
199 return 0;
200 }
201 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_prep);
202
203 int crypto_akcipher_sync_post(struct crypto_akcipher_sync_data *data, int err)
204 {
205 err = crypto_wait_req(err, &data->cwait);
206 if (data->dst)
207 memcpy(data->dst, data->buf, data->dlen);
208 data->dlen = data->req->dst_len;
209 kfree_sensitive(data->req);
210 return err;
211 }
212 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_post);
213
214 int 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 }
230 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_encrypt);
231
232 int 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 }
249 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_decrypt);
250
251 static void crypto_exit_akcipher_ops_sig(struct crypto_tfm *tfm)
252 {
253 struct crypto_akcipher **ctx = crypto_tfm_ctx(tfm);
254
255 crypto_free_akcipher(*ctx);
256 }
257
258 int crypto_init_akcipher_ops_sig(struct crypto_tfm *tfm)
259 {
260 struct crypto_akcipher **ctx = crypto_tfm_ctx(tfm);
261 struct crypto_alg *calg = tfm->__crt_alg;
262 struct crypto_akcipher *akcipher;
263
264 if (!crypto_mod_get(calg))
265 return -EAGAIN;
266
267 akcipher = crypto_create_tfm(calg, &crypto_akcipher_type);
268 if (IS_ERR(akcipher)) {
269 crypto_mod_put(calg);
270 return PTR_ERR(akcipher);
271 }
272
273 *ctx = akcipher;
274 tfm->exit = crypto_exit_akcipher_ops_sig;
275
276 return 0;
277 }
278 EXPORT_SYMBOL_GPL(crypto_init_akcipher_ops_sig);
279
280 MODULE_LICENSE("GPL");
281 MODULE_DESCRIPTION("Generic public key cipher type");
282
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