.. | .. |
---|
| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
---|
1 | 2 | /* In-software asymmetric public-key crypto subtype |
---|
2 | 3 | * |
---|
3 | | - * See Documentation/crypto/asymmetric-keys.txt |
---|
| 4 | + * See Documentation/crypto/asymmetric-keys.rst |
---|
4 | 5 | * |
---|
5 | 6 | * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. |
---|
6 | 7 | * Written by David Howells (dhowells@redhat.com) |
---|
7 | | - * |
---|
8 | | - * This program is free software; you can redistribute it and/or |
---|
9 | | - * modify it under the terms of the GNU General Public Licence |
---|
10 | | - * as published by the Free Software Foundation; either version |
---|
11 | | - * 2 of the Licence, or (at your option) any later version. |
---|
12 | 8 | */ |
---|
13 | 9 | |
---|
14 | 10 | #define pr_fmt(fmt) "PKEY: "fmt |
---|
.. | .. |
---|
21 | 17 | #include <keys/asymmetric-subtype.h> |
---|
22 | 18 | #include <crypto/public_key.h> |
---|
23 | 19 | #include <crypto/akcipher.h> |
---|
| 20 | +#include <crypto/sm2.h> |
---|
| 21 | +#include <crypto/sm3_base.h> |
---|
24 | 22 | |
---|
25 | 23 | MODULE_DESCRIPTION("In-software asymmetric public-key subtype"); |
---|
26 | 24 | MODULE_AUTHOR("Red Hat, Inc."); |
---|
.. | .. |
---|
45 | 43 | { |
---|
46 | 44 | if (key) { |
---|
47 | 45 | kfree(key->key); |
---|
| 46 | + kfree(key->params); |
---|
48 | 47 | kfree(key); |
---|
49 | 48 | } |
---|
50 | 49 | } |
---|
.. | .. |
---|
60 | 59 | } |
---|
61 | 60 | |
---|
62 | 61 | /* |
---|
63 | | - * Verify a signature using a public key. |
---|
| 62 | + * Determine the crypto algorithm name. |
---|
64 | 63 | */ |
---|
65 | | -int public_key_verify_signature(const struct public_key *pkey, |
---|
66 | | - const struct public_key_signature *sig) |
---|
| 64 | +static |
---|
| 65 | +int software_key_determine_akcipher(const char *encoding, |
---|
| 66 | + const char *hash_algo, |
---|
| 67 | + const struct public_key *pkey, |
---|
| 68 | + char alg_name[CRYPTO_MAX_ALG_NAME]) |
---|
67 | 69 | { |
---|
68 | | - struct crypto_wait cwait; |
---|
69 | | - struct crypto_akcipher *tfm; |
---|
70 | | - struct akcipher_request *req; |
---|
71 | | - struct scatterlist sig_sg, digest_sg; |
---|
72 | | - const char *alg_name; |
---|
73 | | - char alg_name_buf[CRYPTO_MAX_ALG_NAME]; |
---|
74 | | - void *output; |
---|
75 | | - unsigned int outlen; |
---|
76 | | - int ret; |
---|
| 70 | + int n; |
---|
77 | 71 | |
---|
78 | | - pr_devel("==>%s()\n", __func__); |
---|
79 | | - |
---|
80 | | - BUG_ON(!pkey); |
---|
81 | | - BUG_ON(!sig); |
---|
82 | | - BUG_ON(!sig->s); |
---|
83 | | - |
---|
84 | | - if (!sig->digest) |
---|
85 | | - return -ENOPKG; |
---|
86 | | - |
---|
87 | | - alg_name = sig->pkey_algo; |
---|
88 | | - if (strcmp(sig->pkey_algo, "rsa") == 0) { |
---|
| 72 | + if (strcmp(encoding, "pkcs1") == 0) { |
---|
89 | 73 | /* The data wangled by the RSA algorithm is typically padded |
---|
90 | 74 | * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447 |
---|
91 | 75 | * sec 8.2]. |
---|
92 | 76 | */ |
---|
93 | | - if (snprintf(alg_name_buf, CRYPTO_MAX_ALG_NAME, |
---|
94 | | - "pkcs1pad(rsa,%s)", sig->hash_algo |
---|
95 | | - ) >= CRYPTO_MAX_ALG_NAME) |
---|
96 | | - return -EINVAL; |
---|
97 | | - alg_name = alg_name_buf; |
---|
| 77 | + if (!hash_algo) |
---|
| 78 | + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, |
---|
| 79 | + "pkcs1pad(%s)", |
---|
| 80 | + pkey->pkey_algo); |
---|
| 81 | + else |
---|
| 82 | + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, |
---|
| 83 | + "pkcs1pad(%s,%s)", |
---|
| 84 | + pkey->pkey_algo, hash_algo); |
---|
| 85 | + return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0; |
---|
98 | 86 | } |
---|
| 87 | + |
---|
| 88 | + if (strcmp(encoding, "raw") == 0) { |
---|
| 89 | + strcpy(alg_name, pkey->pkey_algo); |
---|
| 90 | + return 0; |
---|
| 91 | + } |
---|
| 92 | + |
---|
| 93 | + return -ENOPKG; |
---|
| 94 | +} |
---|
| 95 | + |
---|
| 96 | +static u8 *pkey_pack_u32(u8 *dst, u32 val) |
---|
| 97 | +{ |
---|
| 98 | + memcpy(dst, &val, sizeof(val)); |
---|
| 99 | + return dst + sizeof(val); |
---|
| 100 | +} |
---|
| 101 | + |
---|
| 102 | +/* |
---|
| 103 | + * Query information about a key. |
---|
| 104 | + */ |
---|
| 105 | +static int software_key_query(const struct kernel_pkey_params *params, |
---|
| 106 | + struct kernel_pkey_query *info) |
---|
| 107 | +{ |
---|
| 108 | + struct crypto_akcipher *tfm; |
---|
| 109 | + struct public_key *pkey = params->key->payload.data[asym_crypto]; |
---|
| 110 | + char alg_name[CRYPTO_MAX_ALG_NAME]; |
---|
| 111 | + u8 *key, *ptr; |
---|
| 112 | + int ret, len; |
---|
| 113 | + |
---|
| 114 | + ret = software_key_determine_akcipher(params->encoding, |
---|
| 115 | + params->hash_algo, |
---|
| 116 | + pkey, alg_name); |
---|
| 117 | + if (ret < 0) |
---|
| 118 | + return ret; |
---|
| 119 | + |
---|
| 120 | + tfm = crypto_alloc_akcipher(alg_name, 0, 0); |
---|
| 121 | + if (IS_ERR(tfm)) |
---|
| 122 | + return PTR_ERR(tfm); |
---|
| 123 | + |
---|
| 124 | + ret = -ENOMEM; |
---|
| 125 | + key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, |
---|
| 126 | + GFP_KERNEL); |
---|
| 127 | + if (!key) |
---|
| 128 | + goto error_free_tfm; |
---|
| 129 | + memcpy(key, pkey->key, pkey->keylen); |
---|
| 130 | + ptr = key + pkey->keylen; |
---|
| 131 | + ptr = pkey_pack_u32(ptr, pkey->algo); |
---|
| 132 | + ptr = pkey_pack_u32(ptr, pkey->paramlen); |
---|
| 133 | + memcpy(ptr, pkey->params, pkey->paramlen); |
---|
| 134 | + |
---|
| 135 | + if (pkey->key_is_private) |
---|
| 136 | + ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen); |
---|
| 137 | + else |
---|
| 138 | + ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen); |
---|
| 139 | + if (ret < 0) |
---|
| 140 | + goto error_free_key; |
---|
| 141 | + |
---|
| 142 | + len = crypto_akcipher_maxsize(tfm); |
---|
| 143 | + info->key_size = len * 8; |
---|
| 144 | + info->max_data_size = len; |
---|
| 145 | + info->max_sig_size = len; |
---|
| 146 | + info->max_enc_size = len; |
---|
| 147 | + info->max_dec_size = len; |
---|
| 148 | + info->supported_ops = (KEYCTL_SUPPORTS_ENCRYPT | |
---|
| 149 | + KEYCTL_SUPPORTS_VERIFY); |
---|
| 150 | + if (pkey->key_is_private) |
---|
| 151 | + info->supported_ops |= (KEYCTL_SUPPORTS_DECRYPT | |
---|
| 152 | + KEYCTL_SUPPORTS_SIGN); |
---|
| 153 | + ret = 0; |
---|
| 154 | + |
---|
| 155 | +error_free_key: |
---|
| 156 | + kfree(key); |
---|
| 157 | +error_free_tfm: |
---|
| 158 | + crypto_free_akcipher(tfm); |
---|
| 159 | + pr_devel("<==%s() = %d\n", __func__, ret); |
---|
| 160 | + return ret; |
---|
| 161 | +} |
---|
| 162 | + |
---|
| 163 | +/* |
---|
| 164 | + * Do encryption, decryption and signing ops. |
---|
| 165 | + */ |
---|
| 166 | +static int software_key_eds_op(struct kernel_pkey_params *params, |
---|
| 167 | + const void *in, void *out) |
---|
| 168 | +{ |
---|
| 169 | + const struct public_key *pkey = params->key->payload.data[asym_crypto]; |
---|
| 170 | + struct akcipher_request *req; |
---|
| 171 | + struct crypto_akcipher *tfm; |
---|
| 172 | + struct crypto_wait cwait; |
---|
| 173 | + struct scatterlist in_sg, out_sg; |
---|
| 174 | + char alg_name[CRYPTO_MAX_ALG_NAME]; |
---|
| 175 | + char *key, *ptr; |
---|
| 176 | + int ret; |
---|
| 177 | + |
---|
| 178 | + pr_devel("==>%s()\n", __func__); |
---|
| 179 | + |
---|
| 180 | + ret = software_key_determine_akcipher(params->encoding, |
---|
| 181 | + params->hash_algo, |
---|
| 182 | + pkey, alg_name); |
---|
| 183 | + if (ret < 0) |
---|
| 184 | + return ret; |
---|
99 | 185 | |
---|
100 | 186 | tfm = crypto_alloc_akcipher(alg_name, 0, 0); |
---|
101 | 187 | if (IS_ERR(tfm)) |
---|
.. | .. |
---|
106 | 192 | if (!req) |
---|
107 | 193 | goto error_free_tfm; |
---|
108 | 194 | |
---|
109 | | - ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen); |
---|
| 195 | + key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, |
---|
| 196 | + GFP_KERNEL); |
---|
| 197 | + if (!key) |
---|
| 198 | + goto error_free_req; |
---|
| 199 | + |
---|
| 200 | + memcpy(key, pkey->key, pkey->keylen); |
---|
| 201 | + ptr = key + pkey->keylen; |
---|
| 202 | + ptr = pkey_pack_u32(ptr, pkey->algo); |
---|
| 203 | + ptr = pkey_pack_u32(ptr, pkey->paramlen); |
---|
| 204 | + memcpy(ptr, pkey->params, pkey->paramlen); |
---|
| 205 | + |
---|
| 206 | + if (pkey->key_is_private) |
---|
| 207 | + ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen); |
---|
| 208 | + else |
---|
| 209 | + ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen); |
---|
110 | 210 | if (ret) |
---|
111 | | - goto error_free_req; |
---|
| 211 | + goto error_free_key; |
---|
112 | 212 | |
---|
113 | | - ret = -ENOMEM; |
---|
114 | | - outlen = crypto_akcipher_maxsize(tfm); |
---|
115 | | - output = kmalloc(outlen, GFP_KERNEL); |
---|
116 | | - if (!output) |
---|
117 | | - goto error_free_req; |
---|
118 | | - |
---|
119 | | - sg_init_one(&sig_sg, sig->s, sig->s_size); |
---|
120 | | - sg_init_one(&digest_sg, output, outlen); |
---|
121 | | - akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size, |
---|
122 | | - outlen); |
---|
| 213 | + sg_init_one(&in_sg, in, params->in_len); |
---|
| 214 | + sg_init_one(&out_sg, out, params->out_len); |
---|
| 215 | + akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len, |
---|
| 216 | + params->out_len); |
---|
123 | 217 | crypto_init_wait(&cwait); |
---|
124 | 218 | akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | |
---|
125 | 219 | CRYPTO_TFM_REQ_MAY_SLEEP, |
---|
126 | 220 | crypto_req_done, &cwait); |
---|
127 | 221 | |
---|
128 | | - /* Perform the verification calculation. This doesn't actually do the |
---|
129 | | - * verification, but rather calculates the hash expected by the |
---|
130 | | - * signature and returns that to us. |
---|
131 | | - */ |
---|
132 | | - ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); |
---|
| 222 | + /* Perform the encryption calculation. */ |
---|
| 223 | + switch (params->op) { |
---|
| 224 | + case kernel_pkey_encrypt: |
---|
| 225 | + ret = crypto_akcipher_encrypt(req); |
---|
| 226 | + break; |
---|
| 227 | + case kernel_pkey_decrypt: |
---|
| 228 | + ret = crypto_akcipher_decrypt(req); |
---|
| 229 | + break; |
---|
| 230 | + case kernel_pkey_sign: |
---|
| 231 | + ret = crypto_akcipher_sign(req); |
---|
| 232 | + break; |
---|
| 233 | + default: |
---|
| 234 | + BUG(); |
---|
| 235 | + } |
---|
| 236 | + |
---|
| 237 | + ret = crypto_wait_req(ret, &cwait); |
---|
| 238 | + if (ret == 0) |
---|
| 239 | + ret = req->dst_len; |
---|
| 240 | + |
---|
| 241 | +error_free_key: |
---|
| 242 | + kfree(key); |
---|
| 243 | +error_free_req: |
---|
| 244 | + akcipher_request_free(req); |
---|
| 245 | +error_free_tfm: |
---|
| 246 | + crypto_free_akcipher(tfm); |
---|
| 247 | + pr_devel("<==%s() = %d\n", __func__, ret); |
---|
| 248 | + return ret; |
---|
| 249 | +} |
---|
| 250 | + |
---|
| 251 | +#if IS_REACHABLE(CONFIG_CRYPTO_SM2) |
---|
| 252 | +static int cert_sig_digest_update(const struct public_key_signature *sig, |
---|
| 253 | + struct crypto_akcipher *tfm_pkey) |
---|
| 254 | +{ |
---|
| 255 | + struct crypto_shash *tfm; |
---|
| 256 | + struct shash_desc *desc; |
---|
| 257 | + size_t desc_size; |
---|
| 258 | + unsigned char dgst[SM3_DIGEST_SIZE]; |
---|
| 259 | + int ret; |
---|
| 260 | + |
---|
| 261 | + BUG_ON(!sig->data); |
---|
| 262 | + |
---|
| 263 | + /* SM2 signatures always use the SM3 hash algorithm */ |
---|
| 264 | + if (!sig->hash_algo || strcmp(sig->hash_algo, "sm3") != 0) |
---|
| 265 | + return -EINVAL; |
---|
| 266 | + |
---|
| 267 | + ret = sm2_compute_z_digest(tfm_pkey, SM2_DEFAULT_USERID, |
---|
| 268 | + SM2_DEFAULT_USERID_LEN, dgst); |
---|
133 | 269 | if (ret) |
---|
134 | | - goto out_free_output; |
---|
| 270 | + return ret; |
---|
135 | 271 | |
---|
136 | | - /* Do the actual verification step. */ |
---|
137 | | - if (req->dst_len != sig->digest_size || |
---|
138 | | - memcmp(sig->digest, output, sig->digest_size) != 0) |
---|
139 | | - ret = -EKEYREJECTED; |
---|
| 272 | + tfm = crypto_alloc_shash(sig->hash_algo, 0, 0); |
---|
| 273 | + if (IS_ERR(tfm)) |
---|
| 274 | + return PTR_ERR(tfm); |
---|
140 | 275 | |
---|
141 | | -out_free_output: |
---|
142 | | - kfree(output); |
---|
| 276 | + desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); |
---|
| 277 | + desc = kzalloc(desc_size, GFP_KERNEL); |
---|
| 278 | + if (!desc) { |
---|
| 279 | + ret = -ENOMEM; |
---|
| 280 | + goto error_free_tfm; |
---|
| 281 | + } |
---|
| 282 | + |
---|
| 283 | + desc->tfm = tfm; |
---|
| 284 | + |
---|
| 285 | + ret = crypto_shash_init(desc); |
---|
| 286 | + if (ret < 0) |
---|
| 287 | + goto error_free_desc; |
---|
| 288 | + |
---|
| 289 | + ret = crypto_shash_update(desc, dgst, SM3_DIGEST_SIZE); |
---|
| 290 | + if (ret < 0) |
---|
| 291 | + goto error_free_desc; |
---|
| 292 | + |
---|
| 293 | + ret = crypto_shash_finup(desc, sig->data, sig->data_size, sig->digest); |
---|
| 294 | + |
---|
| 295 | +error_free_desc: |
---|
| 296 | + kfree(desc); |
---|
| 297 | +error_free_tfm: |
---|
| 298 | + crypto_free_shash(tfm); |
---|
| 299 | + return ret; |
---|
| 300 | +} |
---|
| 301 | +#else |
---|
| 302 | +static inline int cert_sig_digest_update( |
---|
| 303 | + const struct public_key_signature *sig, |
---|
| 304 | + struct crypto_akcipher *tfm_pkey) |
---|
| 305 | +{ |
---|
| 306 | + return -ENOTSUPP; |
---|
| 307 | +} |
---|
| 308 | +#endif /* ! IS_REACHABLE(CONFIG_CRYPTO_SM2) */ |
---|
| 309 | + |
---|
| 310 | +/* |
---|
| 311 | + * Verify a signature using a public key. |
---|
| 312 | + */ |
---|
| 313 | +int public_key_verify_signature(const struct public_key *pkey, |
---|
| 314 | + const struct public_key_signature *sig) |
---|
| 315 | +{ |
---|
| 316 | + struct crypto_wait cwait; |
---|
| 317 | + struct crypto_akcipher *tfm; |
---|
| 318 | + struct akcipher_request *req; |
---|
| 319 | + struct scatterlist src_sg; |
---|
| 320 | + char alg_name[CRYPTO_MAX_ALG_NAME]; |
---|
| 321 | + char *buf, *ptr; |
---|
| 322 | + size_t buf_len; |
---|
| 323 | + int ret; |
---|
| 324 | + |
---|
| 325 | + pr_devel("==>%s()\n", __func__); |
---|
| 326 | + |
---|
| 327 | + BUG_ON(!pkey); |
---|
| 328 | + BUG_ON(!sig); |
---|
| 329 | + BUG_ON(!sig->s); |
---|
| 330 | + |
---|
| 331 | + ret = software_key_determine_akcipher(sig->encoding, |
---|
| 332 | + sig->hash_algo, |
---|
| 333 | + pkey, alg_name); |
---|
| 334 | + if (ret < 0) |
---|
| 335 | + return ret; |
---|
| 336 | + |
---|
| 337 | + tfm = crypto_alloc_akcipher(alg_name, 0, 0); |
---|
| 338 | + if (IS_ERR(tfm)) |
---|
| 339 | + return PTR_ERR(tfm); |
---|
| 340 | + |
---|
| 341 | + ret = -ENOMEM; |
---|
| 342 | + req = akcipher_request_alloc(tfm, GFP_KERNEL); |
---|
| 343 | + if (!req) |
---|
| 344 | + goto error_free_tfm; |
---|
| 345 | + |
---|
| 346 | + buf_len = max_t(size_t, pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, |
---|
| 347 | + sig->s_size + sig->digest_size); |
---|
| 348 | + |
---|
| 349 | + buf = kmalloc(buf_len, GFP_KERNEL); |
---|
| 350 | + if (!buf) |
---|
| 351 | + goto error_free_req; |
---|
| 352 | + |
---|
| 353 | + memcpy(buf, pkey->key, pkey->keylen); |
---|
| 354 | + ptr = buf + pkey->keylen; |
---|
| 355 | + ptr = pkey_pack_u32(ptr, pkey->algo); |
---|
| 356 | + ptr = pkey_pack_u32(ptr, pkey->paramlen); |
---|
| 357 | + memcpy(ptr, pkey->params, pkey->paramlen); |
---|
| 358 | + |
---|
| 359 | + if (pkey->key_is_private) |
---|
| 360 | + ret = crypto_akcipher_set_priv_key(tfm, buf, pkey->keylen); |
---|
| 361 | + else |
---|
| 362 | + ret = crypto_akcipher_set_pub_key(tfm, buf, pkey->keylen); |
---|
| 363 | + if (ret) |
---|
| 364 | + goto error_free_buf; |
---|
| 365 | + |
---|
| 366 | + if (strcmp(pkey->pkey_algo, "sm2") == 0 && sig->data_size) { |
---|
| 367 | + ret = cert_sig_digest_update(sig, tfm); |
---|
| 368 | + if (ret) |
---|
| 369 | + goto error_free_buf; |
---|
| 370 | + } |
---|
| 371 | + |
---|
| 372 | + memcpy(buf, sig->s, sig->s_size); |
---|
| 373 | + memcpy(buf + sig->s_size, sig->digest, sig->digest_size); |
---|
| 374 | + |
---|
| 375 | + sg_init_one(&src_sg, buf, sig->s_size + sig->digest_size); |
---|
| 376 | + akcipher_request_set_crypt(req, &src_sg, NULL, sig->s_size, |
---|
| 377 | + sig->digest_size); |
---|
| 378 | + crypto_init_wait(&cwait); |
---|
| 379 | + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | |
---|
| 380 | + CRYPTO_TFM_REQ_MAY_SLEEP, |
---|
| 381 | + crypto_req_done, &cwait); |
---|
| 382 | + ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); |
---|
| 383 | + |
---|
| 384 | +error_free_buf: |
---|
| 385 | + kfree(buf); |
---|
143 | 386 | error_free_req: |
---|
144 | 387 | akcipher_request_free(req); |
---|
145 | 388 | error_free_tfm: |
---|
.. | .. |
---|
167 | 410 | .name_len = sizeof("public_key") - 1, |
---|
168 | 411 | .describe = public_key_describe, |
---|
169 | 412 | .destroy = public_key_destroy, |
---|
| 413 | + .query = software_key_query, |
---|
| 414 | + .eds_op = software_key_eds_op, |
---|
170 | 415 | .verify_signature = public_key_verify_signature_2, |
---|
171 | 416 | }; |
---|
172 | 417 | EXPORT_SYMBOL_GPL(public_key_subtype); |
---|