1 /* 2 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* 7 * Copyright (C) 1998 by the FundsXpress, INC. 8 * 9 * All rights reserved. 10 * 11 * Export of this software from the United States of America may require 12 * a specific license from the United States Government. It is the 13 * responsibility of any person or organization contemplating export to 14 * obtain such a license before exporting. 15 * 16 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 17 * distribute this software and its documentation for any purpose and 18 * without fee is hereby granted, provided that the above copyright 19 * notice appear in all copies and that both that copyright notice and 20 * this permission notice appear in supporting documentation, and that 21 * the name of FundsXpress. not be used in advertising or publicity pertaining 22 * to distribution of the software without specific, written prior 23 * permission. FundsXpress makes no representations about the suitability of 24 * this software for any purpose. It is provided "as is" without express 25 * or implied warranty. 26 * 27 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 29 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 30 */ 31 32 #include "k5-int.h" 33 #include "dk.h" 34 35 #define K5CLENGTH 5 /* 32 bit net byte order integer + one byte seed */ 36 37 /* 38 * Search for a derived key based on the input key, 39 * the usage constant and the dkid byte. 40 * 41 * Return *derived key on success, NULL on failure. 42 */ 43 krb5_keyblock * 44 find_derived_key(krb5_keyusage usage, uchar_t dkid, 45 krb5_keyblock *key) 46 { 47 krb5_dk_node *dknode = key->dk_list; 48 49 while (dknode != NULL) { 50 if (usage == dknode->usage && 51 dkid == dknode->dkid) { 52 KRB5_LOG1(KRB5_INFO, 53 "find_derived_key - MATCH FOUND %d 0x%0x", 54 usage, dkid); 55 return(dknode->derived_key); 56 } 57 dknode = dknode->next; 58 } 59 KRB5_LOG0(KRB5_INFO, "find_derived_key - no match"); 60 return(NULL); 61 } 62 63 /* 64 * Add a derived key to the dk_list for the indicated key. 65 */ 66 krb5_error_code 67 add_derived_key(krb5_keyblock *key, 68 krb5_keyusage usage, uchar_t dkid, 69 krb5_keyblock *derived_key) 70 { 71 krb5_dk_node *dknode; 72 KRB5_LOG1(KRB5_INFO, "add_derived_key: %d 0x%0x", 73 usage, dkid); 74 75 if (key->dk_list == NULL) { 76 key->dk_list = MALLOC(sizeof(krb5_dk_node)); 77 if (key->dk_list == NULL) 78 return (ENOMEM); 79 dknode = key->dk_list; 80 } else { 81 dknode = key->dk_list; 82 /* 83 * Find last derived key in list 84 */ 85 while (dknode->next != NULL) 86 dknode = dknode->next; 87 dknode->next = MALLOC(sizeof(krb5_dk_node)); 88 if (dknode->next == NULL) 89 return (ENOMEM); 90 dknode = dknode->next; 91 } 92 dknode->usage = usage; 93 dknode->dkid = dkid; 94 dknode->derived_key = derived_key; 95 dknode->next = NULL; 96 97 return (0); 98 } 99 100 /* 101 * Utility function to create a new keyblock 102 * Return NULL on failure. 103 */ 104 krb5_keyblock * 105 krb5_create_derived_keyblock(int keysize) 106 { 107 krb5_keyblock *key = MALLOC(sizeof(krb5_keyblock)); 108 109 KRB5_LOG0(KRB5_INFO, "krb5_create_derived_keyblock()"); 110 if (key == NULL) 111 return (NULL); 112 113 bzero(key, sizeof(krb5_keyblock)); 114 115 key->length = keysize; 116 key->contents = (uchar_t *)MALLOC(key->length); 117 if (key->contents == NULL) { 118 FREE(key, sizeof(krb5_keyblock)); 119 return (NULL); 120 } 121 122 bzero(key->contents, key->length); 123 #ifdef _KERNEL 124 key->kef_mt = CRYPTO_MECH_INVALID; 125 key->key_tmpl = NULL; 126 #else 127 key->hKey = CK_INVALID_HANDLE; 128 #endif /* _KERNEL */ 129 return(key); 130 } 131 132 /* 133 * initialize the derived key values in the context. 134 */ 135 krb5_error_code 136 init_derived_keydata(krb5_context context, 137 const struct krb5_enc_provider *enc, 138 krb5_keyblock *key, 139 krb5_keyusage usage, 140 krb5_keyblock **d_encr_key, 141 krb5_keyblock **d_hmac_key) 142 { 143 krb5_error_code rv = 0; 144 unsigned char constantdata[K5CLENGTH]; 145 krb5_keyblock *cached_key; 146 krb5_data d1; 147 148 KRB5_LOG0(KRB5_INFO,"init_ef_derived_keydata()."); 149 150 /* 151 * Get a derived encryption key, either from the cache 152 * or by calculation. 153 */ 154 cached_key = find_derived_key(usage, DK_ENCR_KEY_BYTE, key); 155 if (cached_key != NULL) 156 *d_encr_key = cached_key; 157 else { 158 *d_encr_key = krb5_create_derived_keyblock(key->length); 159 if (*d_encr_key == NULL) { 160 return (ENOMEM); 161 } 162 163 (*d_encr_key)->enctype = key->enctype; 164 165 constantdata[0] = (usage>>24)&0xff; 166 constantdata[1] = (usage>>16)&0xff; 167 constantdata[2] = (usage>>8)&0xff; 168 constantdata[3] = usage&0xff; 169 constantdata[4] = DK_ENCR_KEY_BYTE; 170 171 d1.data = (char *)constantdata; 172 d1.length = sizeof(constantdata); 173 rv = krb5_derive_key(context, enc, key, 174 *d_encr_key, &d1); 175 if (rv != 0) { 176 krb5_free_keyblock(context, *d_encr_key); 177 *d_encr_key = NULL; 178 return (rv); 179 } 180 rv = add_derived_key(key, usage, DK_ENCR_KEY_BYTE, 181 *d_encr_key); 182 183 if (rv != 0) { 184 krb5_free_keyblock(context, *d_encr_key); 185 *d_encr_key = NULL; 186 return (rv); 187 } 188 } 189 190 /* 191 * Get a derived HMAC key, either from the cache 192 * or by calculation. 193 */ 194 cached_key = find_derived_key(usage, DK_HASH_KEY_BYTE, key); 195 if (cached_key != NULL) 196 *d_hmac_key = cached_key; 197 else { 198 *d_hmac_key = krb5_create_derived_keyblock(key->length); 199 if (*d_hmac_key == NULL) { 200 return (ENOMEM); 201 } 202 (*d_hmac_key)->enctype = key->enctype; 203 204 constantdata[0] = (usage>>24)&0xff; 205 constantdata[1] = (usage>>16)&0xff; 206 constantdata[2] = (usage>>8)&0xff; 207 constantdata[3] = usage&0xff; 208 constantdata[4] = DK_HASH_KEY_BYTE; 209 210 d1.data = (char *)constantdata; 211 d1.length = sizeof(constantdata); 212 rv = krb5_derive_key(context, enc, key, *d_hmac_key, &d1); 213 if (rv != 0) { 214 krb5_free_keyblock(context, *d_hmac_key); 215 *d_hmac_key = NULL; 216 return (rv); 217 } 218 #ifdef _KERNEL 219 /* 220 * By default, derived keys get the "mech_type" 221 * that was associated with their parent. 222 * we need to switch the mech type of the derived HMAC key 223 * to correspond to the mech type for the hmac key. 224 */ 225 if ((*d_hmac_key)->kef_mt != context->kef_hash_mt) { 226 (*d_hmac_key)->kef_mt = context->kef_hash_mt; 227 228 if ((*d_hmac_key)->key_tmpl != NULL) { 229 crypto_destroy_ctx_template((*d_hmac_key)->key_tmpl); 230 (*d_hmac_key)->key_tmpl = NULL; 231 } 232 rv = update_key_template(*d_hmac_key); 233 234 if (rv != 0) { 235 krb5_free_keyblock(context, *d_hmac_key); 236 *d_hmac_key = NULL; 237 return (rv); 238 } 239 } 240 #endif /* _KERNEL */ 241 if (rv == 0) { 242 rv = add_derived_key(key, usage, DK_HASH_KEY_BYTE, 243 *d_hmac_key); 244 if (rv != 0) { 245 krb5_free_keyblock(context, *d_hmac_key); 246 *d_hmac_key = NULL; 247 return (rv); 248 } 249 } 250 } 251 KRB5_LOG0(KRB5_INFO,"init_ef_derived_keydata() end."); 252 return (rv); 253 } 254 255 256 krb5_error_code 257 krb5_derive_key(context, enc, inkey, outkey, in_constant) 258 krb5_context context; 259 krb5_const struct krb5_enc_provider *enc; 260 krb5_const krb5_keyblock *inkey; 261 krb5_keyblock *outkey; 262 krb5_const krb5_data *in_constant; 263 { 264 size_t blocksize, keybytes, keylength, n; 265 unsigned char *inblockdata, *outblockdata, *rawkey; 266 krb5_data inblock, outblock; 267 krb5_error_code ret = 0; 268 269 KRB5_LOG0(KRB5_INFO, "krb5_derive_key() start"); 270 271 blocksize = enc->block_size; 272 keybytes = enc->keybytes; 273 keylength = enc->keylength; 274 275 276 if ((inkey->length != keylength) || 277 (outkey->length != keylength)) 278 return(KRB5_CRYPTO_INTERNAL); 279 280 /* allocate and set up buffers */ 281 if ((inblockdata = (unsigned char *) MALLOC(blocksize)) == NULL) 282 return(ENOMEM); 283 284 if ((outblockdata = (unsigned char *) MALLOC(blocksize)) == NULL) { 285 FREE(inblockdata, blocksize); 286 return(ENOMEM); 287 } 288 289 if ((rawkey = (unsigned char *) MALLOC(keybytes)) == NULL) { 290 FREE(outblockdata, blocksize); 291 FREE(inblockdata, blocksize); 292 return(ENOMEM); 293 } 294 295 inblock.data = (char *) inblockdata; 296 inblock.length = blocksize; 297 298 outblock.data = (char *) outblockdata; 299 outblock.length = blocksize; 300 301 /* initialize the input block */ 302 if (in_constant->length == inblock.length) { 303 (void) memcpy(inblock.data, in_constant->data, inblock.length); 304 } else { 305 krb5_nfold(in_constant->length*8, 306 (krb5_const unsigned char *) in_constant->data, 307 inblock.length*8, (unsigned char *) inblock.data); 308 } 309 310 /* loop encrypting the blocks until enough key bytes are generated */ 311 n = 0; 312 while (n < keybytes) { 313 ret = (*(enc->encrypt))(context, inkey, 0, &inblock, &outblock); 314 315 if (ret) { 316 KRB5_LOG(KRB5_INFO, "krb5_derive_key() encrypt error: %d", ret); 317 goto cleanup; 318 } 319 320 if ((keybytes - n) <= outblock.length) { 321 (void) memcpy(rawkey+n, outblock.data, (keybytes - n)); 322 break; 323 } 324 325 (void) memcpy(rawkey+n, outblock.data, outblock.length); 326 (void) memcpy(inblock.data, outblock.data, outblock.length); 327 n += outblock.length; 328 } 329 330 /* postprocess the key */ 331 inblock.data = (char *) rawkey; 332 inblock.length = keybytes; 333 334 outkey->enctype = inkey->enctype; 335 ret = (*(enc->make_key))(context, &inblock, outkey); 336 337 /* clean memory, free resources and exit */ 338 cleanup: 339 (void) memset(inblockdata, 0, blocksize); 340 (void) memset(outblockdata, 0, blocksize); 341 (void) memset(rawkey, 0, keybytes); 342 343 FREE(rawkey, keybytes); 344 FREE(outblockdata, blocksize); 345 FREE(inblockdata, blocksize); 346 347 KRB5_LOG0(KRB5_INFO, "krb5_derive_key() end"); 348 return(ret); 349 } 350