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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 | /* RSA asymmetric public-key algorithm [RFC3447] * * Copyright (c) 2015, Intel Corporation * Authors: Tadeusz Struk <tadeusz.struk@intel.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #include <linux/module.h> #include <crypto/internal/rsa.h> #include <crypto/internal/akcipher.h> #include <crypto/akcipher.h> /* * RSAEP function [RFC3447 sec 5.1.1] * c = m^e mod n; */ static int _rsa_enc(const struct rsa_key *key, MPI c, MPI m) { /* (1) Validate 0 <= m < n */ if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0) return -EINVAL; /* (2) c = m^e mod n */ return mpi_powm(c, m, key->e, key->n); } /* * RSADP function [RFC3447 sec 5.1.2] * m = c^d mod n; */ static int _rsa_dec(const struct rsa_key *key, MPI m, MPI c) { /* (1) Validate 0 <= c < n */ if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0) return -EINVAL; /* (2) m = c^d mod n */ return mpi_powm(m, c, key->d, key->n); } /* * RSASP1 function [RFC3447 sec 5.2.1] * s = m^d mod n */ static int _rsa_sign(const struct rsa_key *key, MPI s, MPI m) { /* (1) Validate 0 <= m < n */ if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0) return -EINVAL; /* (2) s = m^d mod n */ return mpi_powm(s, m, key->d, key->n); } /* * RSAVP1 function [RFC3447 sec 5.2.2] * m = s^e mod n; */ static int _rsa_verify(const struct rsa_key *key, MPI m, MPI s) { /* (1) Validate 0 <= s < n */ if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0) return -EINVAL; /* (2) m = s^e mod n */ return mpi_powm(m, s, key->e, key->n); } static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm) { return akcipher_tfm_ctx(tfm); } static int rsa_enc(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); const struct rsa_key *pkey = rsa_get_key(tfm); MPI m, c = mpi_alloc(0); int ret = 0; int sign; if (!c) return -ENOMEM; if (unlikely(!pkey->n || !pkey->e)) { ret = -EINVAL; goto err_free_c; } if (req->dst_len < mpi_get_size(pkey->n)) { req->dst_len = mpi_get_size(pkey->n); ret = -EOVERFLOW; goto err_free_c; } ret = -ENOMEM; m = mpi_read_raw_from_sgl(req->src, req->src_len); if (!m) goto err_free_c; ret = _rsa_enc(pkey, c, m); if (ret) goto err_free_m; ret = mpi_write_to_sgl(c, req->dst, &req->dst_len, &sign); if (ret) goto err_free_m; if (sign < 0) ret = -EBADMSG; err_free_m: mpi_free(m); err_free_c: mpi_free(c); return ret; } static int rsa_dec(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); const struct rsa_key *pkey = rsa_get_key(tfm); MPI c, m = mpi_alloc(0); int ret = 0; int sign; if (!m) return -ENOMEM; if (unlikely(!pkey->n || !pkey->d)) { ret = -EINVAL; goto err_free_m; } if (req->dst_len < mpi_get_size(pkey->n)) { req->dst_len = mpi_get_size(pkey->n); ret = -EOVERFLOW; goto err_free_m; } ret = -ENOMEM; c = mpi_read_raw_from_sgl(req->src, req->src_len); if (!c) goto err_free_m; ret = _rsa_dec(pkey, m, c); if (ret) goto err_free_c; ret = mpi_write_to_sgl(m, req->dst, &req->dst_len, &sign); if (ret) goto err_free_c; if (sign < 0) ret = -EBADMSG; err_free_c: mpi_free(c); err_free_m: mpi_free(m); return ret; } static int rsa_sign(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); const struct rsa_key *pkey = rsa_get_key(tfm); MPI m, s = mpi_alloc(0); int ret = 0; int sign; if (!s) return -ENOMEM; if (unlikely(!pkey->n || !pkey->d)) { ret = -EINVAL; goto err_free_s; } if (req->dst_len < mpi_get_size(pkey->n)) { req->dst_len = mpi_get_size(pkey->n); ret = -EOVERFLOW; goto err_free_s; } ret = -ENOMEM; m = mpi_read_raw_from_sgl(req->src, req->src_len); if (!m) goto err_free_s; ret = _rsa_sign(pkey, s, m); if (ret) goto err_free_m; ret = mpi_write_to_sgl(s, req->dst, &req->dst_len, &sign); if (ret) goto err_free_m; if (sign < 0) ret = -EBADMSG; err_free_m: mpi_free(m); err_free_s: mpi_free(s); return ret; } static int rsa_verify(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); const struct rsa_key *pkey = rsa_get_key(tfm); MPI s, m = mpi_alloc(0); int ret = 0; int sign; if (!m) return -ENOMEM; if (unlikely(!pkey->n || !pkey->e)) { ret = -EINVAL; goto err_free_m; } if (req->dst_len < mpi_get_size(pkey->n)) { req->dst_len = mpi_get_size(pkey->n); ret = -EOVERFLOW; goto err_free_m; } ret = -ENOMEM; s = mpi_read_raw_from_sgl(req->src, req->src_len); if (!s) { ret = -ENOMEM; goto err_free_m; } ret = _rsa_verify(pkey, m, s); if (ret) goto err_free_s; ret = mpi_write_to_sgl(m, req->dst, &req->dst_len, &sign); if (ret) goto err_free_s; if (sign < 0) ret = -EBADMSG; err_free_s: mpi_free(s); err_free_m: mpi_free(m); return ret; } static int rsa_check_key_length(unsigned int len) { switch (len) { case 512: case 1024: case 1536: case 2048: case 3072: case 4096: return 0; } return -EINVAL; } static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsigned int keylen) { struct rsa_key *pkey = akcipher_tfm_ctx(tfm); int ret; ret = rsa_parse_pub_key(pkey, key, keylen); if (ret) return ret; if (rsa_check_key_length(mpi_get_size(pkey->n) << 3)) { rsa_free_key(pkey); ret = -EINVAL; } return ret; } static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key, unsigned int keylen) { struct rsa_key *pkey = akcipher_tfm_ctx(tfm); int ret; ret = rsa_parse_priv_key(pkey, key, keylen); if (ret) return ret; if (rsa_check_key_length(mpi_get_size(pkey->n) << 3)) { rsa_free_key(pkey); ret = -EINVAL; } return ret; } static int rsa_max_size(struct crypto_akcipher *tfm) { struct rsa_key *pkey = akcipher_tfm_ctx(tfm); return pkey->n ? mpi_get_size(pkey->n) : -EINVAL; } static void rsa_exit_tfm(struct crypto_akcipher *tfm) { struct rsa_key *pkey = akcipher_tfm_ctx(tfm); rsa_free_key(pkey); } static struct akcipher_alg rsa = { .encrypt = rsa_enc, .decrypt = rsa_dec, .sign = rsa_sign, .verify = rsa_verify, .set_priv_key = rsa_set_priv_key, .set_pub_key = rsa_set_pub_key, .max_size = rsa_max_size, .exit = rsa_exit_tfm, .base = { .cra_name = "rsa", .cra_driver_name = "rsa-generic", .cra_priority = 100, .cra_module = THIS_MODULE, .cra_ctxsize = sizeof(struct rsa_key), }, }; static int rsa_init(void) { return crypto_register_akcipher(&rsa); } static void rsa_exit(void) { crypto_unregister_akcipher(&rsa); } module_init(rsa_init); module_exit(rsa_exit); MODULE_ALIAS_CRYPTO("rsa"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("RSA generic algorithm"); |