lib/krb5/build_auth.c

   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 static krb5_error_code
  37 make_etypelist(krb5_context context,
  38                krb5_authdata **auth_data)
  39 {
  40     EtypeList etypes;
  41     krb5_error_code ret;
  42     krb5_authdata ad;
  43     u_char *buf;
  44     size_t len = 0;
  45     size_t buf_size;
  46
  47     ret = _krb5_init_etype(context, KRB5_PDU_NONE,
  48                            &etypes.len, &etypes.val,
  49                            NULL);
  50     if (ret)
  51         return ret;
  52
  53     ASN1_MALLOC_ENCODE(EtypeList, buf, buf_size, &etypes, &len, ret);
  54     if (ret) {
  55         free_EtypeList(&etypes);
  56         return ret;
  57     }
  58     if(buf_size != len)
  59         krb5_abortx(context, "internal error in ASN.1 encoder");
  60     free_EtypeList(&etypes);
  61
  62     ALLOC_SEQ(&ad, 1);
  63     if (ad.val == NULL) {
  64         free(buf);
  65         return krb5_enomem(context);
  66     }
  67
  68     ad.val[0].ad_type = KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION;
  69     ad.val[0].ad_data.length = len;
  70     ad.val[0].ad_data.data = buf;
  71
  72     ASN1_MALLOC_ENCODE(AD_IF_RELEVANT, buf, buf_size, &ad, &len, ret);
  73     if (ret) {
  74         free_AuthorizationData(&ad);
  75         return ret;
  76     }
  77     if(buf_size != len)
  78         krb5_abortx(context, "internal error in ASN.1 encoder");
  79     free_AuthorizationData(&ad);
  80
  81     ALLOC(*auth_data, 1);
  82     if (*auth_data == NULL) {
  83         free(buf);
  84         return krb5_enomem(context);
  85     }
  86
  87     ALLOC_SEQ(*auth_data, 1);
  88     if ((*auth_data)->val == NULL) {
  89         free(*auth_data);
  90         free(buf);
  91         return krb5_enomem(context);
  92     }
  93
  94     (*auth_data)->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
  95     (*auth_data)->val[0].ad_data.length = len;
  96     (*auth_data)->val[0].ad_data.data = buf;
  97
  98     return 0;
  99 }
 100
 101 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 102 _krb5_build_authenticator (krb5_context context,
 103                            krb5_auth_context auth_context,
 104                            krb5_enctype enctype,
 105                            krb5_creds *cred,
 106                            Checksum *cksum,
 107                            krb5_data *result,
 108                            krb5_key_usage usage)
 109 {
 110     Authenticator auth;
 111     u_char *buf = NULL;
 112     size_t buf_size;
 113     size_t len = 0;
 114     krb5_error_code ret;
 115     krb5_crypto crypto;
 116
 117     memset(&auth, 0, sizeof(auth));
 118
 119     auth.authenticator_vno = 5;
 120     copy_Realm(&cred->client->realm, &auth.crealm);
 121     copy_PrincipalName(&cred->client->name, &auth.cname);
 122
 123     krb5_us_timeofday (context, &auth.ctime, &auth.cusec);
 124
 125     ret = krb5_auth_con_getlocalsubkey(context, auth_context, &auth.subkey);
 126     if(ret)
 127         goto fail;
 128
 129     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
 130         if(auth_context->local_seqnumber == 0)
 131             krb5_generate_seq_number (context,
 132                                       &cred->session,
 133                                       &auth_context->local_seqnumber);
 134         ALLOC(auth.seq_number, 1);
 135         if(auth.seq_number == NULL) {
 136             ret = krb5_enomem(context);
 137             goto fail;
 138         }
 139         *auth.seq_number = auth_context->local_seqnumber;
 140     } else
 141         auth.seq_number = NULL;
 142     auth.authorization_data = NULL;
 143
 144     if (cksum) {
 145         ALLOC(auth.cksum, 1);
 146         if (auth.cksum == NULL) {
 147             ret = krb5_enomem(context);
 148             goto fail;
 149         }
 150         ret = copy_Checksum(cksum, auth.cksum);
 151         if (ret)
 152             goto fail;
 153
 154         if (auth.cksum->cksumtype == CKSUMTYPE_GSSAPI) {
 155             /*
 156              * This is not GSS-API specific, we only enable it for
 157              * GSS for now
 158              */
 159             ret = make_etypelist(context, &auth.authorization_data);
 160             if (ret)
 161                 goto fail;
 162         }
 163     }
 164
 165     /* XXX - Copy more to auth_context? */
 166
 167     auth_context->authenticator->ctime = auth.ctime;
 168     auth_context->authenticator->cusec = auth.cusec;
 169
 170     ASN1_MALLOC_ENCODE(Authenticator, buf, buf_size, &auth, &len, ret);
 171     if (ret)
 172         goto fail;
 173     if(buf_size != len)
 174         krb5_abortx(context, "internal error in ASN.1 encoder");
 175
 176     ret = krb5_crypto_init(context, &cred->session, enctype, &crypto);
 177     if (ret)
 178         goto fail;
 179     ret = krb5_encrypt (context,
 180                         crypto,
 181                         usage /* KRB5_KU_AP_REQ_AUTH */,
 182                         buf,
 183                         len,
 184                         result);
 185     krb5_crypto_destroy(context, crypto);
 186
 187     if (ret)
 188         goto fail;
 189
 190  fail:
 191     free_Authenticator (&auth);
 192     free (buf);
 193
 194     return ret;
 195 }