1 /* $NetBSD: cgd_crypto.c,v 1.13 2015/04/25 12:55:04 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Roland C. Dowdeswell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Crypto Framework For cgd.c 34 * 35 * This framework is temporary and awaits a more complete 36 * kernel wide crypto implementation. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: cgd_crypto.c,v 1.13 2015/04/25 12:55:04 riastradh Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/malloc.h> 45 46 #include <dev/cgd_crypto.h> 47 48 #include <crypto/rijndael/rijndael-api-fst.h> 49 #include <crypto/des/des.h> 50 #include <crypto/blowfish/blowfish.h> 51 52 #ifdef DIAGNOSTIC 53 #define DIAGPANIC(x) panic x 54 #else 55 #define DIAGPANIC(x) 56 #endif 57 58 /* 59 * The general framework provides only one generic function. 60 * It takes the name of an algorith and returns a struct cryptfuncs * 61 * for it. It is up to the initialisation routines of the algorithm 62 * to check key size and block size. 63 */ 64 65 static cfunc_init cgd_cipher_aes_init; 66 static cfunc_destroy cgd_cipher_aes_destroy; 67 static cfunc_cipher cgd_cipher_aes_cbc; 68 69 static cfunc_init cgd_cipher_3des_init; 70 static cfunc_destroy cgd_cipher_3des_destroy; 71 static cfunc_cipher cgd_cipher_3des_cbc; 72 73 static cfunc_init cgd_cipher_bf_init; 74 static cfunc_destroy cgd_cipher_bf_destroy; 75 static cfunc_cipher cgd_cipher_bf_cbc; 76 77 static const struct cryptfuncs cf[] = { 78 { 79 .cf_name = "aes-cbc", 80 .cf_init = cgd_cipher_aes_init, 81 .cf_destroy = cgd_cipher_aes_destroy, 82 .cf_cipher = cgd_cipher_aes_cbc, 83 }, 84 { 85 .cf_name = "3des-cbc", 86 .cf_init = cgd_cipher_3des_init, 87 .cf_destroy = cgd_cipher_3des_destroy, 88 .cf_cipher = cgd_cipher_3des_cbc, 89 }, 90 { 91 .cf_name = "blowfish-cbc", 92 .cf_init = cgd_cipher_bf_init, 93 .cf_destroy = cgd_cipher_bf_destroy, 94 .cf_cipher = cgd_cipher_bf_cbc, 95 }, 96 }; 97 const struct cryptfuncs * 98 cryptfuncs_find(const char *alg) 99 { 100 101 for (size_t i = 0; i < __arraycount(cf); i++) 102 if (strcmp(cf[i].cf_name, alg) == 0) 103 return &cf[i]; 104 105 return NULL; 106 } 107 108 typedef void (*cipher_func)(void *, void *, const void *, size_t); 109 110 static void 111 cgd_cipher_uio_cbc(void *privdata, cipher_func cipher, 112 struct uio *dstuio, struct uio *srcuio); 113 114 /* 115 * cgd_cipher_uio_cbc takes a simple cbc cipher and iterates 116 * it over two struct uio's. It presumes that the cipher function 117 * that is passed to it keeps the IV state between calls. 118 * 119 * We assume that the caller has ensured that each segment is evenly 120 * divisible by the block size, which for the cgd is a valid assumption. 121 * If we were to make this code more generic, we might need to take care 122 * of this case, either by issuing an error or copying the data. 123 */ 124 125 static void 126 cgd_cipher_uio_cbc(void *privdata, cipher_func cipher, 127 struct uio *dstuio, struct uio *srcuio) 128 { 129 const struct iovec *dst; 130 const struct iovec *src; 131 int dstnum; 132 int dstoff = 0; 133 int srcnum; 134 int srcoff = 0; 135 136 dst = dstuio->uio_iov; 137 dstnum = dstuio->uio_iovcnt; 138 src = srcuio->uio_iov; 139 srcnum = srcuio->uio_iovcnt; 140 for (;;) { 141 int l = MIN(dst->iov_len - dstoff, src->iov_len - srcoff); 142 u_int8_t *d = (u_int8_t *)dst->iov_base + dstoff; 143 const u_int8_t *s = (const u_int8_t *)src->iov_base + srcoff; 144 145 cipher(privdata, d, s, l); 146 147 dstoff += l; 148 srcoff += l; 149 /* 150 * We assume that {dst,src} == {dst,src}->iov_len, 151 * because it should not be possible for it not to be. 152 */ 153 if (dstoff == dst->iov_len) { 154 dstoff = 0; 155 dstnum--; 156 dst++; 157 } 158 if (srcoff == src->iov_len) { 159 srcoff = 0; 160 srcnum--; 161 src++; 162 } 163 if (!srcnum || !dstnum) 164 break; 165 } 166 } 167 168 /* 169 * AES Framework 170 */ 171 172 /* 173 * NOTE: we do not store the blocksize in here, because it is not 174 * variable [yet], we hardcode the blocksize to 16 (128 bits). 175 */ 176 177 struct aes_privdata { 178 keyInstance ap_enckey; 179 keyInstance ap_deckey; 180 }; 181 182 struct aes_encdata { 183 keyInstance *ae_key; /* key for this direction */ 184 u_int8_t ae_iv[16]; /* Initialization Vector */ 185 }; 186 187 static void * 188 cgd_cipher_aes_init(size_t keylen, const void *key, size_t *blocksize) 189 { 190 struct aes_privdata *ap; 191 192 if (!blocksize) 193 return NULL; 194 if (keylen != 128 && keylen != 192 && keylen != 256) 195 return NULL; 196 if (*blocksize == (size_t)-1) 197 *blocksize = 128; 198 if (*blocksize != 128) 199 return NULL; 200 ap = malloc(sizeof(*ap), M_DEVBUF, 0); 201 if (!ap) 202 return NULL; 203 rijndael_makeKey(&ap->ap_enckey, DIR_ENCRYPT, keylen, key); 204 rijndael_makeKey(&ap->ap_deckey, DIR_DECRYPT, keylen, key); 205 return ap; 206 } 207 208 static void 209 cgd_cipher_aes_destroy(void *data) 210 { 211 struct aes_privdata *apd = data; 212 213 explicit_memset(apd, 0, sizeof(*apd)); 214 free(apd, M_DEVBUF); 215 } 216 217 static void 218 aes_cbc_enc_int(void *privdata, void *dst, const void *src, size_t len) 219 { 220 struct aes_encdata *ae = privdata; 221 cipherInstance cipher; 222 223 rijndael_cipherInit(&cipher, MODE_CBC, ae->ae_iv); 224 rijndael_blockEncrypt(&cipher, ae->ae_key, src, len * 8, dst); 225 (void)memcpy(ae->ae_iv, (u_int8_t *)dst + (len - 16), 16); 226 } 227 228 static void 229 aes_cbc_dec_int(void *privdata, void *dst, const void *src, size_t len) 230 { 231 struct aes_encdata *ae = privdata; 232 cipherInstance cipher; 233 234 rijndael_cipherInit(&cipher, MODE_CBC, ae->ae_iv); 235 rijndael_blockDecrypt(&cipher, ae->ae_key, src, len * 8, dst); 236 (void)memcpy(ae->ae_iv, (const u_int8_t *)src + (len - 16), 16); 237 } 238 239 static void 240 cgd_cipher_aes_cbc(void *privdata, struct uio *dstuio, 241 struct uio *srcuio, const void *iv, int dir) 242 { 243 struct aes_privdata *apd = privdata; 244 struct aes_encdata encd; 245 246 (void)memcpy(encd.ae_iv, iv, 16); 247 switch (dir) { 248 case CGD_CIPHER_ENCRYPT: 249 encd.ae_key = &apd->ap_enckey; 250 cgd_cipher_uio_cbc(&encd, aes_cbc_enc_int, dstuio, srcuio); 251 break; 252 case CGD_CIPHER_DECRYPT: 253 encd.ae_key = &apd->ap_deckey; 254 cgd_cipher_uio_cbc(&encd, aes_cbc_dec_int, dstuio, srcuio); 255 break; 256 default: 257 DIAGPANIC(("%s: unrecognised direction %d", __func__, dir)); 258 } 259 } 260 261 /* 262 * 3DES Framework 263 */ 264 265 struct c3des_privdata { 266 des_key_schedule cp_key1; 267 des_key_schedule cp_key2; 268 des_key_schedule cp_key3; 269 }; 270 271 struct c3des_encdata { 272 des_key_schedule *ce_key1; 273 des_key_schedule *ce_key2; 274 des_key_schedule *ce_key3; 275 u_int8_t ce_iv[8]; 276 }; 277 278 static void * 279 cgd_cipher_3des_init(size_t keylen, const void *key, size_t *blocksize) 280 { 281 struct c3des_privdata *cp; 282 int error = 0; 283 des_cblock *block; 284 285 if (!blocksize) 286 return NULL; 287 if (*blocksize == (size_t)-1) 288 *blocksize = 64; 289 if (keylen != (DES_KEY_SZ * 3 * 8) || *blocksize != 64) 290 return NULL; 291 cp = malloc(sizeof(*cp), M_DEVBUF, 0); 292 if (!cp) 293 return NULL; 294 block = __UNCONST(key); 295 error = des_key_sched(block, cp->cp_key1); 296 error |= des_key_sched(block + 1, cp->cp_key2); 297 error |= des_key_sched(block + 2, cp->cp_key3); 298 if (error) { 299 explicit_memset(cp, 0, sizeof(*cp)); 300 free(cp, M_DEVBUF); 301 return NULL; 302 } 303 return cp; 304 } 305 306 static void 307 cgd_cipher_3des_destroy(void *data) 308 { 309 struct c3des_privdata *cp = data; 310 311 explicit_memset(cp, 0, sizeof(*cp)); 312 free(cp, M_DEVBUF); 313 } 314 315 static void 316 c3des_cbc_enc_int(void *privdata, void *dst, const void *src, size_t len) 317 { 318 struct c3des_encdata *ce = privdata; 319 320 des_ede3_cbc_encrypt(src, dst, len, *ce->ce_key1, *ce->ce_key2, 321 *ce->ce_key3, (des_cblock *)ce->ce_iv, 1); 322 (void)memcpy(ce->ce_iv, (const u_int8_t *)dst + (len - 8), 8); 323 } 324 325 static void 326 c3des_cbc_dec_int(void *privdata, void *dst, const void *src, size_t len) 327 { 328 struct c3des_encdata *ce = privdata; 329 330 des_ede3_cbc_encrypt(src, dst, len, *ce->ce_key1, *ce->ce_key2, 331 *ce->ce_key3, (des_cblock *)ce->ce_iv, 0); 332 (void)memcpy(ce->ce_iv, (const u_int8_t *)src + (len - 8), 8); 333 } 334 335 static void 336 cgd_cipher_3des_cbc(void *privdata, struct uio *dstuio, 337 struct uio *srcuio, const void *iv, int dir) 338 { 339 struct c3des_privdata *cp = privdata; 340 struct c3des_encdata ce; 341 342 (void)memcpy(ce.ce_iv, iv, 8); 343 ce.ce_key1 = &cp->cp_key1; 344 ce.ce_key2 = &cp->cp_key2; 345 ce.ce_key3 = &cp->cp_key3; 346 switch (dir) { 347 case CGD_CIPHER_ENCRYPT: 348 cgd_cipher_uio_cbc(&ce, c3des_cbc_enc_int, dstuio, srcuio); 349 break; 350 case CGD_CIPHER_DECRYPT: 351 cgd_cipher_uio_cbc(&ce, c3des_cbc_dec_int, dstuio, srcuio); 352 break; 353 default: 354 DIAGPANIC(("%s: unrecognised direction %d", __func__, dir)); 355 } 356 } 357 358 /* 359 * Blowfish Framework 360 */ 361 362 struct bf_privdata { 363 BF_KEY bp_key; 364 }; 365 366 struct bf_encdata { 367 BF_KEY *be_key; 368 u_int8_t be_iv[8]; 369 }; 370 371 static void * 372 cgd_cipher_bf_init(size_t keylen, const void *key, size_t *blocksize) 373 { 374 struct bf_privdata *bp; 375 376 if (!blocksize) 377 return NULL; 378 if (keylen < 40 || keylen > 448 || (keylen % 8 != 0)) 379 return NULL; 380 if (*blocksize == (size_t)-1) 381 *blocksize = 64; 382 if (*blocksize != 64) 383 return NULL; 384 bp = malloc(sizeof(*bp), M_DEVBUF, 0); 385 if (!bp) 386 return NULL; 387 BF_set_key(&bp->bp_key, keylen / 8, key); 388 return bp; 389 } 390 391 static void 392 cgd_cipher_bf_destroy(void *data) 393 { 394 struct bf_privdata *bp = data; 395 396 explicit_memset(bp, 0, sizeof(*bp)); 397 free(bp, M_DEVBUF); 398 } 399 400 static void 401 bf_cbc_enc_int(void *privdata, void *dst, const void *src, size_t len) 402 { 403 struct bf_encdata *be = privdata; 404 405 BF_cbc_encrypt(src, dst, len, be->be_key, be->be_iv, 1); 406 (void)memcpy(be->be_iv, (u_int8_t *)dst + (len - 8), 8); 407 } 408 409 static void 410 bf_cbc_dec_int(void *privdata, void *dst, const void *src, size_t len) 411 { 412 struct bf_encdata *be = privdata; 413 414 BF_cbc_encrypt(src, dst, len, be->be_key, be->be_iv, 0); 415 (void)memcpy(be->be_iv, (const u_int8_t *)src + (len - 8), 8); 416 } 417 418 static void 419 cgd_cipher_bf_cbc(void *privdata, struct uio *dstuio, 420 struct uio *srcuio, const void *iv, int dir) 421 { 422 struct bf_privdata *bp = privdata; 423 struct bf_encdata be; 424 425 (void)memcpy(be.be_iv, iv, 8); 426 be.be_key = &bp->bp_key; 427 switch (dir) { 428 case CGD_CIPHER_ENCRYPT: 429 cgd_cipher_uio_cbc(&be, bf_cbc_enc_int, dstuio, srcuio); 430 break; 431 case CGD_CIPHER_DECRYPT: 432 cgd_cipher_uio_cbc(&be, bf_cbc_dec_int, dstuio, srcuio); 433 break; 434 default: 435 DIAGPANIC(("%s: unrecognised direction %d", __func__, dir)); 436 } 437 438 } 439