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10#define pr_fmt(fmt) "PKEY: "fmt
11#include <linux/module.h>
12#include <linux/export.h>
13#include <linux/kernel.h>
14#include <linux/slab.h>
15#include <linux/seq_file.h>
16#include <linux/scatterlist.h>
17#include <linux/asn1.h>
18#include <keys/asymmetric-subtype.h>
19#include <crypto/public_key.h>
20#include <crypto/akcipher.h>
21#include <crypto/sm2.h>
22#include <crypto/sm3_base.h>
23
24MODULE_DESCRIPTION("In-software asymmetric public-key subtype");
25MODULE_AUTHOR("Red Hat, Inc.");
26MODULE_LICENSE("GPL");
27
28
29
30
31static void public_key_describe(const struct key *asymmetric_key,
32 struct seq_file *m)
33{
34 struct public_key *key = asymmetric_key->payload.data[asym_crypto];
35
36 if (key)
37 seq_printf(m, "%s.%s", key->id_type, key->pkey_algo);
38}
39
40
41
42
43void public_key_free(struct public_key *key)
44{
45 if (key) {
46 kfree(key->key);
47 kfree(key->params);
48 kfree(key);
49 }
50}
51EXPORT_SYMBOL_GPL(public_key_free);
52
53
54
55
56static void public_key_destroy(void *payload0, void *payload3)
57{
58 public_key_free(payload0);
59 public_key_signature_free(payload3);
60}
61
62
63
64
65static
66int software_key_determine_akcipher(const char *encoding,
67 const char *hash_algo,
68 const struct public_key *pkey,
69 char alg_name[CRYPTO_MAX_ALG_NAME])
70{
71 int n;
72
73 if (strcmp(encoding, "pkcs1") == 0) {
74
75
76
77
78 if (!hash_algo)
79 n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME,
80 "pkcs1pad(%s)",
81 pkey->pkey_algo);
82 else
83 n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME,
84 "pkcs1pad(%s,%s)",
85 pkey->pkey_algo, hash_algo);
86 return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0;
87 }
88
89 if (strcmp(encoding, "raw") == 0 ||
90 strcmp(encoding, "x962") == 0) {
91 strcpy(alg_name, pkey->pkey_algo);
92 return 0;
93 }
94
95 return -ENOPKG;
96}
97
98static u8 *pkey_pack_u32(u8 *dst, u32 val)
99{
100 memcpy(dst, &val, sizeof(val));
101 return dst + sizeof(val);
102}
103
104
105
106
107static int software_key_query(const struct kernel_pkey_params *params,
108 struct kernel_pkey_query *info)
109{
110 struct crypto_akcipher *tfm;
111 struct public_key *pkey = params->key->payload.data[asym_crypto];
112 char alg_name[CRYPTO_MAX_ALG_NAME];
113 u8 *key, *ptr;
114 int ret, len;
115
116 ret = software_key_determine_akcipher(params->encoding,
117 params->hash_algo,
118 pkey, alg_name);
119 if (ret < 0)
120 return ret;
121
122 tfm = crypto_alloc_akcipher(alg_name, 0, 0);
123 if (IS_ERR(tfm))
124 return PTR_ERR(tfm);
125
126 ret = -ENOMEM;
127 key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen,
128 GFP_KERNEL);
129 if (!key)
130 goto error_free_tfm;
131 memcpy(key, pkey->key, pkey->keylen);
132 ptr = key + pkey->keylen;
133 ptr = pkey_pack_u32(ptr, pkey->algo);
134 ptr = pkey_pack_u32(ptr, pkey->paramlen);
135 memcpy(ptr, pkey->params, pkey->paramlen);
136
137 if (pkey->key_is_private)
138 ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen);
139 else
140 ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen);
141 if (ret < 0)
142 goto error_free_key;
143
144 len = crypto_akcipher_maxsize(tfm);
145 info->key_size = len * 8;
146 info->max_data_size = len;
147 info->max_sig_size = len;
148 info->max_enc_size = len;
149 info->max_dec_size = len;
150 info->supported_ops = (KEYCTL_SUPPORTS_ENCRYPT |
151 KEYCTL_SUPPORTS_VERIFY);
152 if (pkey->key_is_private)
153 info->supported_ops |= (KEYCTL_SUPPORTS_DECRYPT |
154 KEYCTL_SUPPORTS_SIGN);
155 ret = 0;
156
157error_free_key:
158 kfree(key);
159error_free_tfm:
160 crypto_free_akcipher(tfm);
161 pr_devel("<==%s() = %d\n", __func__, ret);
162 return ret;
163}
164
165
166
167
168static int software_key_eds_op(struct kernel_pkey_params *params,
169 const void *in, void *out)
170{
171 const struct public_key *pkey = params->key->payload.data[asym_crypto];
172 struct akcipher_request *req;
173 struct crypto_akcipher *tfm;
174 struct crypto_wait cwait;
175 struct scatterlist in_sg, out_sg;
176 char alg_name[CRYPTO_MAX_ALG_NAME];
177 char *key, *ptr;
178 int ret;
179
180 pr_devel("==>%s()\n", __func__);
181
182 ret = software_key_determine_akcipher(params->encoding,
183 params->hash_algo,
184 pkey, alg_name);
185 if (ret < 0)
186 return ret;
187
188 tfm = crypto_alloc_akcipher(alg_name, 0, 0);
189 if (IS_ERR(tfm))
190 return PTR_ERR(tfm);
191
192 ret = -ENOMEM;
193 req = akcipher_request_alloc(tfm, GFP_KERNEL);
194 if (!req)
195 goto error_free_tfm;
196
197 key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen,
198 GFP_KERNEL);
199 if (!key)
200 goto error_free_req;
201
202 memcpy(key, pkey->key, pkey->keylen);
203 ptr = key + pkey->keylen;
204 ptr = pkey_pack_u32(ptr, pkey->algo);
205 ptr = pkey_pack_u32(ptr, pkey->paramlen);
206 memcpy(ptr, pkey->params, pkey->paramlen);
207
208 if (pkey->key_is_private)
209 ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen);
210 else
211 ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen);
212 if (ret)
213 goto error_free_key;
214
215 sg_init_one(&in_sg, in, params->in_len);
216 sg_init_one(&out_sg, out, params->out_len);
217 akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
218 params->out_len);
219 crypto_init_wait(&cwait);
220 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
221 CRYPTO_TFM_REQ_MAY_SLEEP,
222 crypto_req_done, &cwait);
223
224
225 switch (params->op) {
226 case kernel_pkey_encrypt:
227 ret = crypto_akcipher_encrypt(req);
228 break;
229 case kernel_pkey_decrypt:
230 ret = crypto_akcipher_decrypt(req);
231 break;
232 case kernel_pkey_sign:
233 ret = crypto_akcipher_sign(req);
234 break;
235 default:
236 BUG();
237 }
238
239 ret = crypto_wait_req(ret, &cwait);
240 if (ret == 0)
241 ret = req->dst_len;
242
243error_free_key:
244 kfree(key);
245error_free_req:
246 akcipher_request_free(req);
247error_free_tfm:
248 crypto_free_akcipher(tfm);
249 pr_devel("<==%s() = %d\n", __func__, ret);
250 return ret;
251}
252
253#if IS_REACHABLE(CONFIG_CRYPTO_SM2)
254static int cert_sig_digest_update(const struct public_key_signature *sig,
255 struct crypto_akcipher *tfm_pkey)
256{
257 struct crypto_shash *tfm;
258 struct shash_desc *desc;
259 size_t desc_size;
260 unsigned char dgst[SM3_DIGEST_SIZE];
261 int ret;
262
263 BUG_ON(!sig->data);
264
265 ret = sm2_compute_z_digest(tfm_pkey, SM2_DEFAULT_USERID,
266 SM2_DEFAULT_USERID_LEN, dgst);
267 if (ret)
268 return ret;
269
270 tfm = crypto_alloc_shash(sig->hash_algo, 0, 0);
271 if (IS_ERR(tfm))
272 return PTR_ERR(tfm);
273
274 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
275 desc = kzalloc(desc_size, GFP_KERNEL);
276 if (!desc) {
277 ret = -ENOMEM;
278 goto error_free_tfm;
279 }
280
281 desc->tfm = tfm;
282
283 ret = crypto_shash_init(desc);
284 if (ret < 0)
285 goto error_free_desc;
286
287 ret = crypto_shash_update(desc, dgst, SM3_DIGEST_SIZE);
288 if (ret < 0)
289 goto error_free_desc;
290
291 ret = crypto_shash_finup(desc, sig->data, sig->data_size, sig->digest);
292
293error_free_desc:
294 kfree(desc);
295error_free_tfm:
296 crypto_free_shash(tfm);
297 return ret;
298}
299#else
300static inline int cert_sig_digest_update(
301 const struct public_key_signature *sig,
302 struct crypto_akcipher *tfm_pkey)
303{
304 return -ENOTSUPP;
305}
306#endif
307
308
309
310
311int public_key_verify_signature(const struct public_key *pkey,
312 const struct public_key_signature *sig)
313{
314 struct crypto_wait cwait;
315 struct crypto_akcipher *tfm;
316 struct akcipher_request *req;
317 struct scatterlist src_sg[2];
318 char alg_name[CRYPTO_MAX_ALG_NAME];
319 char *key, *ptr;
320 int ret;
321
322 pr_devel("==>%s()\n", __func__);
323
324 BUG_ON(!pkey);
325 BUG_ON(!sig);
326 BUG_ON(!sig->s);
327
328 ret = software_key_determine_akcipher(sig->encoding,
329 sig->hash_algo,
330 pkey, alg_name);
331 if (ret < 0)
332 return ret;
333
334 tfm = crypto_alloc_akcipher(alg_name, 0, 0);
335 if (IS_ERR(tfm))
336 return PTR_ERR(tfm);
337
338 ret = -ENOMEM;
339 req = akcipher_request_alloc(tfm, GFP_KERNEL);
340 if (!req)
341 goto error_free_tfm;
342
343 key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen,
344 GFP_KERNEL);
345 if (!key)
346 goto error_free_req;
347
348 memcpy(key, pkey->key, pkey->keylen);
349 ptr = key + pkey->keylen;
350 ptr = pkey_pack_u32(ptr, pkey->algo);
351 ptr = pkey_pack_u32(ptr, pkey->paramlen);
352 memcpy(ptr, pkey->params, pkey->paramlen);
353
354 if (pkey->key_is_private)
355 ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen);
356 else
357 ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen);
358 if (ret)
359 goto error_free_key;
360
361 if (sig->pkey_algo && strcmp(sig->pkey_algo, "sm2") == 0 &&
362 sig->data_size) {
363 ret = cert_sig_digest_update(sig, tfm);
364 if (ret)
365 goto error_free_key;
366 }
367
368 sg_init_table(src_sg, 2);
369 sg_set_buf(&src_sg[0], sig->s, sig->s_size);
370 sg_set_buf(&src_sg[1], sig->digest, sig->digest_size);
371 akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size,
372 sig->digest_size);
373 crypto_init_wait(&cwait);
374 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
375 CRYPTO_TFM_REQ_MAY_SLEEP,
376 crypto_req_done, &cwait);
377 ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
378
379error_free_key:
380 kfree(key);
381error_free_req:
382 akcipher_request_free(req);
383error_free_tfm:
384 crypto_free_akcipher(tfm);
385 pr_devel("<==%s() = %d\n", __func__, ret);
386 if (WARN_ON_ONCE(ret > 0))
387 ret = -EINVAL;
388 return ret;
389}
390EXPORT_SYMBOL_GPL(public_key_verify_signature);
391
392static int public_key_verify_signature_2(const struct key *key,
393 const struct public_key_signature *sig)
394{
395 const struct public_key *pk = key->payload.data[asym_crypto];
396 return public_key_verify_signature(pk, sig);
397}
398
399
400
401
402struct asymmetric_key_subtype public_key_subtype = {
403 .owner = THIS_MODULE,
404 .name = "public_key",
405 .name_len = sizeof("public_key") - 1,
406 .describe = public_key_describe,
407 .destroy = public_key_destroy,
408 .query = software_key_query,
409 .eds_op = software_key_eds_op,
410 .verify_signature = public_key_verify_signature_2,
411};
412EXPORT_SYMBOL_GPL(public_key_subtype);
413
