1 /* 2 * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the Institute nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include "krb5_locl.h" 35 36 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 37 krb5_mk_safe(krb5_context context, 38 krb5_auth_context auth_context, 39 const krb5_data *userdata, 40 krb5_data *outbuf, 41 krb5_replay_data *outdata) 42 { 43 krb5_error_code ret; 44 KRB_SAFE s; 45 u_char *buf = NULL; 46 size_t buf_size; 47 size_t len = 0; 48 krb5_crypto crypto; 49 krb5_keyblock *key; 50 krb5_replay_data rdata; 51 52 if ((auth_context->flags & 53 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) && 54 outdata == NULL) 55 return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */ 56 57 if (auth_context->local_subkey) 58 key = auth_context->local_subkey; 59 else if (auth_context->remote_subkey) 60 key = auth_context->remote_subkey; 61 else 62 key = auth_context->keyblock; 63 64 s.pvno = 5; 65 s.msg_type = krb_safe; 66 67 memset(&rdata, 0, sizeof(rdata)); 68 69 s.safe_body.user_data = *userdata; 70 71 krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec); 72 73 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 74 s.safe_body.timestamp = &rdata.timestamp; 75 s.safe_body.usec = &rdata.usec; 76 } else { 77 s.safe_body.timestamp = NULL; 78 s.safe_body.usec = NULL; 79 } 80 81 if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) { 82 outdata->timestamp = rdata.timestamp; 83 outdata->usec = rdata.usec; 84 } 85 86 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) { 87 rdata.seq = auth_context->local_seqnumber; 88 s.safe_body.seq_number = &rdata.seq; 89 } else 90 s.safe_body.seq_number = NULL; 91 92 if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE) 93 outdata->seq = auth_context->local_seqnumber; 94 95 s.safe_body.s_address = auth_context->local_address; 96 s.safe_body.r_address = auth_context->remote_address; 97 98 s.cksum.cksumtype = 0; 99 s.cksum.checksum.data = NULL; 100 s.cksum.checksum.length = 0; 101 102 ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, &s, &len, ret); 103 if (ret) 104 return ret; 105 if(buf_size != len) 106 krb5_abortx(context, "internal error in ASN.1 encoder"); 107 ret = krb5_crypto_init(context, key, 0, &crypto); 108 if (ret) { 109 free (buf); 110 return ret; 111 } 112 ret = krb5_create_checksum(context, 113 crypto, 114 KRB5_KU_KRB_SAFE_CKSUM, 115 0, 116 buf, 117 len, 118 &s.cksum); 119 krb5_crypto_destroy(context, crypto); 120 if (ret) { 121 free (buf); 122 return ret; 123 } 124 125 free(buf); 126 ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, &s, &len, ret); 127 free_Checksum (&s.cksum); 128 if(ret) 129 return ret; 130 if(buf_size != len) 131 krb5_abortx(context, "internal error in ASN.1 encoder"); 132 133 outbuf->length = len; 134 outbuf->data = buf; 135 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) 136 auth_context->local_seqnumber = 137 (auth_context->local_seqnumber + 1) & 0xFFFFFFFF; 138 return 0; 139 } 140