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;
  45     size_t buf_size;
  46
  47     ret = krb5_init_etype(context, &etypes.len, &etypes.val, NULL);
  48     if (ret)
  49         return ret;
  50
  51     ASN1_MALLOC_ENCODE(EtypeList, buf, buf_size, &etypes, &len, ret);
  52     if (ret) {
  53         free_EtypeList(&etypes);
  54         return ret;
  55     }
  56     if(buf_size != len)
  57         krb5_abortx(context, "internal error in ASN.1 encoder");
  58     free_EtypeList(&etypes);
  59
  60     ALLOC_SEQ(&ad, 1);
  61     if (ad.val == NULL) {
  62         free(buf);
  63         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
  64         return ENOMEM;
  65     }
  66
  67     ad.val[0].ad_type = KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION;
  68     ad.val[0].ad_data.length = len;
  69     ad.val[0].ad_data.data = buf;
  70
  71     ASN1_MALLOC_ENCODE(AD_IF_RELEVANT, buf, buf_size, &ad, &len, ret);
  72     if (ret) {
  73         free_AuthorizationData(&ad);
  74         return ret;
  75     }
  76     if(buf_size != len)
  77         krb5_abortx(context, "internal error in ASN.1 encoder");
  78     free_AuthorizationData(&ad);
  79
  80     ALLOC(*auth_data, 1);
  81     if (*auth_data == NULL) {
  82         free(buf);
  83         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
  84         return ENOMEM;
  85     }
  86
  87     ALLOC_SEQ(*auth_data, 1);
  88     if ((*auth_data)->val == NULL) {
  89         free(*auth_data);
  90         free(buf);
  91         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
  92         return ENOMEM;
  93     }
  94
  95     (*auth_data)->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
  96     (*auth_data)->val[0].ad_data.length = len;
  97     (*auth_data)->val[0].ad_data.data = buf;
  98
  99     return 0;
 100 }
 101
 102 krb5_error_code KRB5_LIB_FUNCTION
 103 _krb5_build_authenticator(krb5_context context,
 104                           krb5_auth_context auth_context,
 105                           krb5_enctype enctype,
 106                           krb5_creds *cred,
 107                           Checksum *cksum,
 108                           krb5_data *result,
 109                           krb5_key_usage usage)
 110 {
 111     Authenticator auth;
 112     u_char *buf = NULL;
 113     size_t buf_size;
 114     size_t len;
 115     krb5_error_code ret;
 116     krb5_crypto crypto;
 117
 118     memset(&auth, 0, sizeof(auth));
 119
 120     auth.authenticator_vno = 5;
 121     copy_Realm(&cred->client->realm, &auth.crealm);
 122     copy_PrincipalName(&cred->client->name, &auth.cname);
 123
 124     krb5_us_timeofday (context, &auth.ctime, &auth.cusec);
 125
 126     ret = krb5_auth_con_getlocalsubkey(context, auth_context, &auth.subkey);
 127     if(ret)
 128         goto fail;
 129
 130     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
 131         if(auth_context->local_seqnumber == 0)
 132             krb5_generate_seq_number (context,
 133                                       &cred->session,
 134                                       &auth_context->local_seqnumber);
 135         ALLOC(auth.seq_number, 1);
 136         if(auth.seq_number == NULL) {
 137             ret = ENOMEM;
 138             goto fail;
 139         }
 140         *auth.seq_number = auth_context->local_seqnumber;
 141     } else
 142         auth.seq_number = NULL;
 143     auth.authorization_data = NULL;
 144
 145     if (cksum) {
 146         ALLOC(auth.cksum, 1);
 147         if (auth.cksum == NULL) {
 148             ret = ENOMEM;
 149             goto fail;
 150         }
 151         ret = copy_Checksum(cksum, auth.cksum);
 152         if (ret)
 153             goto fail;
 154
 155         if (auth.cksum->cksumtype == CKSUMTYPE_GSSAPI) {
 156             /*
 157              * This is not GSS-API specific, we only enable it for
 158              * GSS for now
 159              */
 160             ret = make_etypelist(context, &auth.authorization_data);
 161             if (ret)
 162                 goto fail;
 163         }
 164     }
 165
 166     /* XXX - Copy more to auth_context? */
 167
 168     auth_context->authenticator->ctime = auth.ctime;
 169     auth_context->authenticator->cusec = auth.cusec;
 170
 171     ASN1_MALLOC_ENCODE(Authenticator, buf, buf_size, &auth, &len, ret);
 172     if (ret)
 173         goto fail;
 174     if(buf_size != len)
 175         krb5_abortx(context, "internal error in ASN.1 encoder");
 176
 177     ret = krb5_crypto_init(context, &cred->session, enctype, &crypto);
 178     if (ret)
 179         goto fail;
 180     ret = krb5_encrypt (context,
 181                         crypto,
 182                         usage /* KRB5_KU_AP_REQ_AUTH */,
 183                         buf,
 184                         len,
 185                         result);
 186     krb5_crypto_destroy(context, crypto);
 187
 188     if (ret)
 189         goto fail;
 190
 191  fail:
 192     free_Authenticator (&auth);
 193     free (buf);
 194
 195     return ret;
 196 }