1 /* 2 * Copyright (c) 1997-2007 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_rd_priv(krb5_context context, 38 krb5_auth_context auth_context, 39 const krb5_data *inbuf, 40 krb5_data *outbuf, 41 krb5_replay_data *outdata) 42 { 43 krb5_error_code ret; 44 KRB_PRIV priv; 45 EncKrbPrivPart part; 46 size_t len; 47 krb5_data plain; 48 krb5_keyblock *key; 49 krb5_crypto crypto; 50 51 krb5_data_zero(outbuf); 52 53 if ((auth_context->flags & 54 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) 55 { 56 if (outdata == NULL) { 57 krb5_clear_error_message (context); 58 return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */ 59 } 60 /* if these fields are not present in the priv-part, silently 61 return zero */ 62 memset(outdata, 0, sizeof(*outdata)); 63 } 64 65 memset(&priv, 0, sizeof(priv)); 66 ret = decode_KRB_PRIV (inbuf->data, inbuf->length, &priv, &len); 67 if (ret) { 68 krb5_clear_error_message (context); 69 goto failure; 70 } 71 if (priv.pvno != 5) { 72 krb5_clear_error_message (context); 73 ret = KRB5KRB_AP_ERR_BADVERSION; 74 goto failure; 75 } 76 if (priv.msg_type != krb_priv) { 77 krb5_clear_error_message (context); 78 ret = KRB5KRB_AP_ERR_MSG_TYPE; 79 goto failure; 80 } 81 82 if (auth_context->remote_subkey) 83 key = auth_context->remote_subkey; 84 else if (auth_context->local_subkey) 85 key = auth_context->local_subkey; 86 else 87 key = auth_context->keyblock; 88 89 ret = krb5_crypto_init(context, key, 0, &crypto); 90 if (ret) 91 goto failure; 92 ret = krb5_decrypt_EncryptedData(context, 93 crypto, 94 KRB5_KU_KRB_PRIV, 95 &priv.enc_part, 96 &plain); 97 krb5_crypto_destroy(context, crypto); 98 if (ret) 99 goto failure; 100 101 ret = decode_EncKrbPrivPart (plain.data, plain.length, &part, &len); 102 krb5_data_free (&plain); 103 if (ret) { 104 krb5_clear_error_message (context); 105 goto failure; 106 } 107 108 /* check sender address */ 109 110 if (part.s_address 111 && auth_context->remote_address 112 && !krb5_address_compare (context, 113 auth_context->remote_address, 114 part.s_address)) { 115 krb5_clear_error_message (context); 116 ret = KRB5KRB_AP_ERR_BADADDR; 117 goto failure_part; 118 } 119 120 /* check receiver address */ 121 122 if (part.r_address 123 && auth_context->local_address 124 && !krb5_address_compare (context, 125 auth_context->local_address, 126 part.r_address)) { 127 krb5_clear_error_message (context); 128 ret = KRB5KRB_AP_ERR_BADADDR; 129 goto failure_part; 130 } 131 132 /* check timestamp */ 133 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 134 krb5_timestamp sec; 135 136 krb5_timeofday (context, &sec); 137 if (part.timestamp == NULL || 138 part.usec == NULL || 139 abs(*part.timestamp - sec) > context->max_skew) { 140 krb5_clear_error_message (context); 141 ret = KRB5KRB_AP_ERR_SKEW; 142 goto failure_part; 143 } 144 } 145 146 /* XXX - check replay cache */ 147 148 /* check sequence number. since MIT krb5 cannot generate a sequence 149 number of zero but instead generates no sequence number, we accept that 150 */ 151 152 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) { 153 if ((part.seq_number == NULL 154 && auth_context->remote_seqnumber != 0) 155 || (part.seq_number != NULL 156 && *part.seq_number != auth_context->remote_seqnumber)) { 157 krb5_clear_error_message (context); 158 ret = KRB5KRB_AP_ERR_BADORDER; 159 goto failure_part; 160 } 161 auth_context->remote_seqnumber++; 162 } 163 164 ret = krb5_data_copy (outbuf, part.user_data.data, part.user_data.length); 165 if (ret) 166 goto failure_part; 167 168 if ((auth_context->flags & 169 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) { 170 if(part.timestamp) 171 outdata->timestamp = *part.timestamp; 172 if(part.usec) 173 outdata->usec = *part.usec; 174 if(part.seq_number) 175 outdata->seq = *part.seq_number; 176 } 177 178 failure_part: 179 free_EncKrbPrivPart (&part); 180 181 failure: 182 free_KRB_PRIV (&priv); 183 return ret; 184 } 185