1 /* 2 * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 #pragma ident "%Z%%M% %I% %E% SMI" 6 7 /* 8 * Copyright (C) 1998 by the FundsXpress, INC. 9 * 10 * All rights reserved. 11 * 12 * Export of this software from the United States of America may require 13 * a specific license from the United States Government. It is the 14 * responsibility of any person or organization contemplating export to 15 * obtain such a license before exporting. 16 * 17 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 18 * distribute this software and its documentation for any purpose and 19 * without fee is hereby granted, provided that the above copyright 20 * notice appear in all copies and that both that copyright notice and 21 * this permission notice appear in supporting documentation, and that 22 * the name of FundsXpress. not be used in advertising or publicity pertaining 23 * to distribution of the software without specific, written prior 24 * permission. FundsXpress makes no representations about the suitability of 25 * this software for any purpose. It is provided "as is" without express 26 * or implied warranty. 27 * 28 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 29 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 30 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 31 */ 32 33 #include <k5-int.h> 34 #include <etypes.h> 35 #include <dk.h> 36 37 #define K5CLENGTH 5 /* 32 bit net byte order integer + one byte seed */ 38 39 /* 40 * Derive the key for checksum calculation. 41 * This is only called (currently) for SHA1-DES3 42 * checksum types. 43 * 44 * The primary benefit here is that a KEF template 45 * is created for use when doing the HMAC operation which 46 * saves ALOT of computation cycles and improves performance. 47 */ 48 static krb5_error_code 49 derive_cksum_key(krb5_context context, 50 struct krb5_enc_provider *enc, 51 const krb5_keyblock *key, 52 krb5_keyusage usage, 53 krb5_keyblock **outkey) 54 { 55 krb5_error_code ret = 0; 56 krb5_keyblock *cached_key = NULL; 57 krb5_data d1; 58 unsigned char constantdata[K5CLENGTH]; 59 60 cached_key = find_derived_key(usage, DK_CKSUM_KEY_BYTE, 61 (krb5_keyblock *)key); 62 if (cached_key) 63 *outkey = cached_key; 64 else { 65 *outkey = krb5_create_derived_keyblock(key->length); 66 if (*outkey == NULL) 67 return (ENOMEM); 68 69 constantdata[0] = (usage>>24)&0xff; 70 constantdata[1] = (usage>>16)&0xff; 71 constantdata[2] = (usage>>8)&0xff; 72 constantdata[3] = usage&0xff; 73 constantdata[4] = DK_CKSUM_KEY_BYTE; 74 75 d1.data = (char *)constantdata; 76 d1.length = sizeof(constantdata); 77 78 ret = krb5_derive_key(context, enc, key, 79 *outkey, &d1); 80 if (ret) { 81 krb5_free_keyblock(context, *outkey); 82 *outkey = NULL; 83 return (ret); 84 } 85 #ifdef _KERNEL 86 /* 87 * By default, derived keys get the "mech_type" 88 * that was associated with their parent. 89 * we need to switch the mech_type to correspond 90 * to the checksum mech type. 91 */ 92 if (ret == 0 && 93 (*outkey)->kef_mt != context->kef_cksum_mt) { 94 (*outkey)->kef_mt = context->kef_cksum_mt; 95 if ((*outkey)->key_tmpl != NULL) { 96 crypto_destroy_ctx_template((*outkey)->key_tmpl); 97 (*outkey)->key_tmpl = NULL; 98 } 99 ret = update_key_template(*outkey); 100 } 101 #endif /* _KERNEL */ 102 if (ret == 0) 103 ret = add_derived_key((krb5_keyblock *)key, usage, 104 DK_CKSUM_KEY_BYTE, 105 *outkey); 106 } 107 finish: 108 KRB5_LOG0(KRB5_INFO, "derive_cksum_key() end."); 109 return (ret); 110 } 111 112 /* ARGSUSED */ 113 krb5_error_code 114 krb5_dk_make_checksum(context, hash, key, usage, input, output) 115 krb5_context context; 116 krb5_const struct krb5_hash_provider *hash; 117 krb5_const krb5_keyblock *key; 118 krb5_keyusage usage; 119 krb5_const krb5_data *input; 120 krb5_data *output; 121 { 122 int i; 123 krb5_error_code ret; 124 krb5_keyblock *cksum_key = NULL; 125 struct krb5_enc_provider *enc = NULL; 126 127 KRB5_LOG0(KRB5_INFO, "krb5_dk_make_checksum() start"); 128 129 for (i=0; i<krb5_enctypes_length; i++) { 130 if (krb5_enctypes_list[i].etype == key->enctype) 131 break; 132 } 133 if (i == krb5_enctypes_length) { 134 KRB5_LOG(KRB5_ERR, "krb5_ck_make_checksum bad enctype: %d", 135 key->enctype); 136 return(KRB5_BAD_ENCTYPE); 137 } 138 enc = (struct krb5_enc_provider *)krb5_enctypes_list[i].enc; 139 140 #ifdef _KERNEL 141 if (key->kef_key.ck_data == NULL && 142 (ret = init_key_kef(krb5_enctypes_list[i].kef_cipher_mt, 143 (krb5_keyblock *)key))) 144 goto cleanup; 145 #endif 146 ret = derive_cksum_key(context, enc, key, usage, &cksum_key); 147 if (ret != 0) 148 goto cleanup; 149 150 #ifdef _KERNEL 151 if ((ret = krb5_hmac(context, (krb5_keyblock *)cksum_key, 152 input, output))) { 153 KRB5_LOG(KRB5_ERR, "krb5_hmac error: %0x", ret); 154 (void) memset(output->data, 0, output->length); 155 } 156 #else 157 if ((ret = krb5_hmac(context, hash, cksum_key, 1, input, output)) != 0) { 158 KRB5_LOG(KRB5_ERR, "krb5_hmac error: %0x", ret); 159 (void) memset(output->data, 0, output->length); 160 } 161 #endif /* _KERNEL */ 162 cleanup: 163 164 KRB5_LOG0(KRB5_INFO, "krb5_dk_make_checksum() end"); 165 return(ret); 166 } 167 168