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 RCSID("$Id$");
  37
  38 static krb5_error_code
  39 make_etypelist(krb5_context context,
  40                krb5_authdata **auth_data)
  41 {
  42     EtypeList etypes;
  43     krb5_error_code ret;
  44     krb5_authdata ad;
  45     u_char *buf;
  46     size_t len;
  47     size_t buf_size;
  48
  49     ret = krb5_init_etype(context, &etypes.len, &etypes.val, 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         krb5_set_error_string(context, "malloc: out of memory");
  66         return ENOMEM;
  67     }
  68
  69     ad.val[0].ad_type = KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION;
  70     ad.val[0].ad_data.length = len;
  71     ad.val[0].ad_data.data = buf;
  72
  73     ASN1_MALLOC_ENCODE(AD_IF_RELEVANT, buf, buf_size, &ad, &len, ret);
  74     if (ret) {
  75         free_AuthorizationData(&ad);
  76         return ret;
  77     }
  78     if(buf_size != len)
  79         krb5_abortx(context, "internal error in ASN.1 encoder");
  80     free_AuthorizationData(&ad);
  81
  82     ALLOC(*auth_data, 1);
  83     if (*auth_data == NULL) {
  84         krb5_set_error_string(context, "malloc: out of memory");
  85         return ENOMEM;
  86     }
  87
  88     ALLOC_SEQ(*auth_data, 1);
  89     if ((*auth_data)->val == NULL) {
  90         free(buf);
  91         krb5_set_error_string(context, "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                           Authenticator **auth_result,
 109                           krb5_data *result,
 110                           krb5_key_usage usage)
 111 {
 112     Authenticator *auth;
 113     u_char *buf = NULL;
 114     size_t buf_size;
 115     size_t len;
 116     krb5_error_code ret;
 117     krb5_crypto crypto;
 118
 119     auth = calloc(1, sizeof(*auth));
 120     if (auth == NULL) {
 121         krb5_set_error_string(context, "malloc: out of memory");
 122         return ENOMEM;
 123     }
 124
 125     auth->authenticator_vno = 5;
 126     copy_Realm(&cred->client->realm, &auth->crealm);
 127     copy_PrincipalName(&cred->client->name, &auth->cname);
 128
 129     krb5_us_timeofday (context, &auth->ctime, &auth->cusec);
 130
 131     ret = krb5_auth_con_getlocalsubkey(context, auth_context, &auth->subkey);
 132     if(ret)
 133         goto fail;
 134
 135     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
 136         if(auth_context->local_seqnumber == 0)
 137             krb5_generate_seq_number (context,
 138                                       &cred->session,
 139                                       &auth_context->local_seqnumber);
 140         ALLOC(auth->seq_number, 1);
 141         if(auth->seq_number == NULL) {
 142             ret = ENOMEM;
 143             goto fail;
 144         }
 145         *auth->seq_number = auth_context->local_seqnumber;
 146     } else
 147         auth->seq_number = NULL;
 148     auth->authorization_data = NULL;
 149     auth->cksum = cksum;
 150
 151     if (cksum != NULL && cksum->cksumtype == CKSUMTYPE_GSSAPI) {
 152         /*
 153          * This is not GSS-API specific, we only enable it for
 154          * GSS for now
 155          */
 156         ret = make_etypelist(context, &auth->authorization_data);
 157         if (ret)
 158             goto fail;
 159     }
 160
 161     /* XXX - Copy more to auth_context? */
 162
 163     auth_context->authenticator->ctime = auth->ctime;
 164     auth_context->authenticator->cusec = auth->cusec;
 165
 166     ASN1_MALLOC_ENCODE(Authenticator, buf, buf_size, auth, &len, ret);
 167     if (ret)
 168         goto fail;
 169     if(buf_size != len)
 170         krb5_abortx(context, "internal error in ASN.1 encoder");
 171
 172     ret = krb5_crypto_init(context, &cred->session, enctype, &crypto);
 173     if (ret)
 174         goto fail;
 175     ret = krb5_encrypt (context,
 176                         crypto,
 177                         usage /* KRB5_KU_AP_REQ_AUTH */,
 178                         buf + buf_size - len,
 179                         len,
 180                         result);
 181     krb5_crypto_destroy(context, crypto);
 182
 183     if (ret)
 184         goto fail;
 185
 186     free (buf);
 187
 188     if (auth_result)
 189         *auth_result = auth;
 190     else {
 191         /* Don't free the `cksum', it's allocated by the caller */
 192         auth->cksum = NULL;
 193         free_Authenticator (auth);
 194         free (auth);
 195     }
 196     return ret;
 197   fail:
 198     free_Authenticator (auth);
 199     free (auth);
 200     free (buf);
 201     return ret;
 202 }