155682Smarkm/* 2233294Sstas * Copyright (c) 1997-2007 Kungliga Tekniska H��gskolan 3233294Sstas * (Royal Institute of Technology, Stockholm, Sweden). 4233294Sstas * All rights reserved. 555682Smarkm * 6233294Sstas * Redistribution and use in source and binary forms, with or without 7233294Sstas * modification, are permitted provided that the following conditions 8233294Sstas * are met: 955682Smarkm * 10233294Sstas * 1. Redistributions of source code must retain the above copyright 11233294Sstas * notice, this list of conditions and the following disclaimer. 1255682Smarkm * 13233294Sstas * 2. Redistributions in binary form must reproduce the above copyright 14233294Sstas * notice, this list of conditions and the following disclaimer in the 15233294Sstas * documentation and/or other materials provided with the distribution. 1655682Smarkm * 17233294Sstas * 3. Neither the name of the Institute nor the names of its contributors 18233294Sstas * may be used to endorse or promote products derived from this software 19233294Sstas * without specific prior written permission. 2055682Smarkm * 21233294Sstas * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22233294Sstas * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23233294Sstas * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24233294Sstas * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25233294Sstas * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26233294Sstas * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27233294Sstas * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28233294Sstas * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29233294Sstas * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30233294Sstas * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31233294Sstas * SUCH DAMAGE. 3255682Smarkm */ 3355682Smarkm 34233294Sstas#include "krb5_locl.h" 3555682Smarkm 36233294SstasKRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 3755682Smarkmkrb5_rd_priv(krb5_context context, 3855682Smarkm krb5_auth_context auth_context, 3955682Smarkm const krb5_data *inbuf, 4055682Smarkm krb5_data *outbuf, 41178825Sdfr krb5_replay_data *outdata) 4255682Smarkm{ 43178825Sdfr krb5_error_code ret; 44178825Sdfr KRB_PRIV priv; 45178825Sdfr EncKrbPrivPart part; 46178825Sdfr size_t len; 47178825Sdfr krb5_data plain; 48178825Sdfr krb5_keyblock *key; 49178825Sdfr krb5_crypto crypto; 5055682Smarkm 51233294Sstas krb5_data_zero(outbuf); 5255682Smarkm 53233294Sstas if ((auth_context->flags & 54233294Sstas (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) 55233294Sstas { 56233294Sstas if (outdata == NULL) { 57233294Sstas krb5_clear_error_message (context); 58233294Sstas return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */ 59233294Sstas } 60233294Sstas /* if these fields are not present in the priv-part, silently 61233294Sstas return zero */ 62233294Sstas memset(outdata, 0, sizeof(*outdata)); 63178825Sdfr } 6455682Smarkm 65178825Sdfr memset(&priv, 0, sizeof(priv)); 66178825Sdfr ret = decode_KRB_PRIV (inbuf->data, inbuf->length, &priv, &len); 67178825Sdfr if (ret) { 68233294Sstas krb5_clear_error_message (context); 69178825Sdfr goto failure; 70178825Sdfr } 71178825Sdfr if (priv.pvno != 5) { 72233294Sstas krb5_clear_error_message (context); 73178825Sdfr ret = KRB5KRB_AP_ERR_BADVERSION; 74178825Sdfr goto failure; 75178825Sdfr } 76178825Sdfr if (priv.msg_type != krb_priv) { 77233294Sstas krb5_clear_error_message (context); 78178825Sdfr ret = KRB5KRB_AP_ERR_MSG_TYPE; 79178825Sdfr goto failure; 80178825Sdfr } 8155682Smarkm 82178825Sdfr if (auth_context->remote_subkey) 83178825Sdfr key = auth_context->remote_subkey; 84178825Sdfr else if (auth_context->local_subkey) 85178825Sdfr key = auth_context->local_subkey; 86178825Sdfr else 87178825Sdfr key = auth_context->keyblock; 88178825Sdfr 89178825Sdfr ret = krb5_crypto_init(context, key, 0, &crypto); 90178825Sdfr if (ret) 91178825Sdfr goto failure; 92178825Sdfr ret = krb5_decrypt_EncryptedData(context, 93178825Sdfr crypto, 94178825Sdfr KRB5_KU_KRB_PRIV, 95178825Sdfr &priv.enc_part, 96178825Sdfr &plain); 97178825Sdfr krb5_crypto_destroy(context, crypto); 98233294Sstas if (ret) 99178825Sdfr goto failure; 100178825Sdfr 101178825Sdfr ret = decode_EncKrbPrivPart (plain.data, plain.length, &part, &len); 102178825Sdfr krb5_data_free (&plain); 103178825Sdfr if (ret) { 104233294Sstas krb5_clear_error_message (context); 105178825Sdfr goto failure; 106178825Sdfr } 107233294Sstas 108178825Sdfr /* check sender address */ 10955682Smarkm 110178825Sdfr if (part.s_address 111178825Sdfr && auth_context->remote_address 112178825Sdfr && !krb5_address_compare (context, 113178825Sdfr auth_context->remote_address, 114178825Sdfr part.s_address)) { 115233294Sstas krb5_clear_error_message (context); 116178825Sdfr ret = KRB5KRB_AP_ERR_BADADDR; 117178825Sdfr goto failure_part; 118178825Sdfr } 11955682Smarkm 120178825Sdfr /* check receiver address */ 12155682Smarkm 122178825Sdfr if (part.r_address 123178825Sdfr && auth_context->local_address 124178825Sdfr && !krb5_address_compare (context, 125178825Sdfr auth_context->local_address, 126178825Sdfr part.r_address)) { 127233294Sstas krb5_clear_error_message (context); 128178825Sdfr ret = KRB5KRB_AP_ERR_BADADDR; 129178825Sdfr goto failure_part; 130178825Sdfr } 13155682Smarkm 132178825Sdfr /* check timestamp */ 133178825Sdfr if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 134178825Sdfr krb5_timestamp sec; 13555682Smarkm 136178825Sdfr krb5_timeofday (context, &sec); 137178825Sdfr if (part.timestamp == NULL || 138178825Sdfr part.usec == NULL || 139178825Sdfr abs(*part.timestamp - sec) > context->max_skew) { 140233294Sstas krb5_clear_error_message (context); 141178825Sdfr ret = KRB5KRB_AP_ERR_SKEW; 142178825Sdfr goto failure_part; 143178825Sdfr } 144178825Sdfr } 14555682Smarkm 146178825Sdfr /* XXX - check replay cache */ 14755682Smarkm 148178825Sdfr /* check sequence number. since MIT krb5 cannot generate a sequence 149178825Sdfr number of zero but instead generates no sequence number, we accept that 150178825Sdfr */ 15172445Sassar 152178825Sdfr if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) { 153178825Sdfr if ((part.seq_number == NULL 154178825Sdfr && auth_context->remote_seqnumber != 0) 155178825Sdfr || (part.seq_number != NULL 156178825Sdfr && *part.seq_number != auth_context->remote_seqnumber)) { 157233294Sstas krb5_clear_error_message (context); 158178825Sdfr ret = KRB5KRB_AP_ERR_BADORDER; 159178825Sdfr goto failure_part; 160178825Sdfr } 161178825Sdfr auth_context->remote_seqnumber++; 162178825Sdfr } 16355682Smarkm 164178825Sdfr ret = krb5_data_copy (outbuf, part.user_data.data, part.user_data.length); 165178825Sdfr if (ret) 166178825Sdfr goto failure_part; 16755682Smarkm 168233294Sstas if ((auth_context->flags & 169178825Sdfr (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) { 170178825Sdfr if(part.timestamp) 171178825Sdfr outdata->timestamp = *part.timestamp; 172178825Sdfr if(part.usec) 173178825Sdfr outdata->usec = *part.usec; 174178825Sdfr if(part.seq_number) 175178825Sdfr outdata->seq = *part.seq_number; 176178825Sdfr } 17755682Smarkm 178178825Sdfr failure_part: 179178825Sdfr free_EncKrbPrivPart (&part); 18055682Smarkm 181178825Sdfr failure: 182178825Sdfr free_KRB_PRIV (&priv); 183178825Sdfr return ret; 18455682Smarkm} 185