1 /* $NetBSD: rd_priv.c,v 1.1.1.1 2011/04/13 18:15:37 elric Exp $ */ 2 3 /* 4 * Copyright (c) 1997-2007 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 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 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "krb5_locl.h" 37 38 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 39 krb5_rd_priv(krb5_context context, 40 krb5_auth_context auth_context, 41 const krb5_data *inbuf, 42 krb5_data *outbuf, 43 krb5_replay_data *outdata) 44 { 45 krb5_error_code ret; 46 KRB_PRIV priv; 47 EncKrbPrivPart part; 48 size_t len; 49 krb5_data plain; 50 krb5_keyblock *key; 51 krb5_crypto crypto; 52 53 krb5_data_zero(outbuf); 54 55 if ((auth_context->flags & 56 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) 57 { 58 if (outdata == NULL) { 59 krb5_clear_error_message (context); 60 return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */ 61 } 62 /* if these fields are not present in the priv-part, silently 63 return zero */ 64 memset(outdata, 0, sizeof(*outdata)); 65 } 66 67 memset(&priv, 0, sizeof(priv)); 68 ret = decode_KRB_PRIV (inbuf->data, inbuf->length, &priv, &len); 69 if (ret) { 70 krb5_clear_error_message (context); 71 goto failure; 72 } 73 if (priv.pvno != 5) { 74 krb5_clear_error_message (context); 75 ret = KRB5KRB_AP_ERR_BADVERSION; 76 goto failure; 77 } 78 if (priv.msg_type != krb_priv) { 79 krb5_clear_error_message (context); 80 ret = KRB5KRB_AP_ERR_MSG_TYPE; 81 goto failure; 82 } 83 84 if (auth_context->remote_subkey) 85 key = auth_context->remote_subkey; 86 else if (auth_context->local_subkey) 87 key = auth_context->local_subkey; 88 else 89 key = auth_context->keyblock; 90 91 ret = krb5_crypto_init(context, key, 0, &crypto); 92 if (ret) 93 goto failure; 94 ret = krb5_decrypt_EncryptedData(context, 95 crypto, 96 KRB5_KU_KRB_PRIV, 97 &priv.enc_part, 98 &plain); 99 krb5_crypto_destroy(context, crypto); 100 if (ret) 101 goto failure; 102 103 ret = decode_EncKrbPrivPart (plain.data, plain.length, &part, &len); 104 krb5_data_free (&plain); 105 if (ret) { 106 krb5_clear_error_message (context); 107 goto failure; 108 } 109 110 /* check sender address */ 111 112 if (part.s_address 113 && auth_context->remote_address 114 && !krb5_address_compare (context, 115 auth_context->remote_address, 116 part.s_address)) { 117 krb5_clear_error_message (context); 118 ret = KRB5KRB_AP_ERR_BADADDR; 119 goto failure_part; 120 } 121 122 /* check receiver address */ 123 124 if (part.r_address 125 && auth_context->local_address 126 && !krb5_address_compare (context, 127 auth_context->local_address, 128 part.r_address)) { 129 krb5_clear_error_message (context); 130 ret = KRB5KRB_AP_ERR_BADADDR; 131 goto failure_part; 132 } 133 134 /* check timestamp */ 135 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 136 krb5_timestamp sec; 137 138 krb5_timeofday (context, &sec); 139 if (part.timestamp == NULL || 140 part.usec == NULL || 141 abs(*part.timestamp - sec) > context->max_skew) { 142 krb5_clear_error_message (context); 143 ret = KRB5KRB_AP_ERR_SKEW; 144 goto failure_part; 145 } 146 } 147 148 /* XXX - check replay cache */ 149 150 /* check sequence number. since MIT krb5 cannot generate a sequence 151 number of zero but instead generates no sequence number, we accept that 152 */ 153 154 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) { 155 if ((part.seq_number == NULL 156 && auth_context->remote_seqnumber != 0) 157 || (part.seq_number != NULL 158 && *part.seq_number != auth_context->remote_seqnumber)) { 159 krb5_clear_error_message (context); 160 ret = KRB5KRB_AP_ERR_BADORDER; 161 goto failure_part; 162 } 163 auth_context->remote_seqnumber++; 164 } 165 166 ret = krb5_data_copy (outbuf, part.user_data.data, part.user_data.length); 167 if (ret) 168 goto failure_part; 169 170 if ((auth_context->flags & 171 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) { 172 if(part.timestamp) 173 outdata->timestamp = *part.timestamp; 174 if(part.usec) 175 outdata->usec = *part.usec; 176 if(part.seq_number) 177 outdata->seq = *part.seq_number; 178 } 179 180 failure_part: 181 free_EncKrbPrivPart (&part); 182 183 failure: 184 free_KRB_PRIV (&priv); 185 return ret; 186 } 187