1  /*
  2   * Copyright (c) 1997 - 2002 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_error_code
 37  _krb5_mk_req_internal(krb5_context context,
 38  		      krb5_auth_context *auth_context,
 39  		      const krb5_flags ap_req_options,
 40  		      krb5_data *in_data,
 41  		      krb5_ccache ccache,
 42  		      krb5_creds *in_creds,
 43  		      krb5_data *outbuf,
 44  		      krb5_key_usage checksum_usage,
 45  		      krb5_key_usage encrypt_usage)
 46  {
 47      krb5_error_code ret;
 48      krb5_data authenticator;
 49      Checksum c;
 50      Checksum *c_opt;
 51      krb5_auth_context ac;
 52  
 53      if(auth_context) {
 54  	if(*auth_context == NULL)
 55  	    ret = krb5_auth_con_init(context, auth_context);
 56  	else
 57  	    ret = 0;
 58  	ac = *auth_context;
 59      } else
 60  	ret = krb5_auth_con_init(context, &ac);
 61      if(ret)
 62  	return ret;
 63  
 64      if(ac->local_subkey == NULL && (ap_req_options & AP_OPTS_USE_SUBKEY)) {
 65  	ret = krb5_auth_con_generatelocalsubkey(context,
 66  						ac,
 67  						&in_creds->session);
 68  	if(ret)
 69  	    goto out;
 70      }
 71  
 72      krb5_free_keyblock(context, ac->keyblock);
 73      ret = krb5_copy_keyblock(context, &in_creds->session, &ac->keyblock);
 74      if (ret)
 75  	goto out;
 76  
 77      /*
 78       * Now that we know the enctype, setup PFS if possible
 79       */
 80      if (auth_context && (ap_req_options & AP_OPTS_USE_PFS) != 0) {
 81  	ret = _krb5_auth_con_setup_pfs(context, ac, ac->keyblock->keytype);
 82  	if (ret)
 83  	    goto out;
 84      }
 85  
 86      /* it's unclear what type of checksum we can use.  try the best one, except:
 87       * a) if it's configured differently for the current realm, or
 88       * b) if the session key is des-cbc-crc
 89       */
 90  
 91      if (in_data) {
 92  	if(ac->keyblock->keytype == ETYPE_DES_CBC_CRC) {
 93  	    /* this is to make DCE secd (and older MIT kdcs?) happy */
 94  	    ret = krb5_create_checksum(context,
 95  				       NULL,
 96  				       0,
 97  				       CKSUMTYPE_RSA_MD4,
 98  				       in_data->data,
 99  				       in_data->length,
100  				       &c);
101  	} else if(ac->keyblock->keytype == ETYPE_ARCFOUR_HMAC_MD5 ||
102  		  ac->keyblock->keytype == ETYPE_ARCFOUR_HMAC_MD5_56 ||
103  		  ac->keyblock->keytype == ETYPE_DES_CBC_MD4 ||
104  		  ac->keyblock->keytype == ETYPE_DES_CBC_MD5) {
105  	    /* this is to make MS kdc happy */
106  	    ret = krb5_create_checksum(context,
107  				       NULL,
108  				       0,
109  				       CKSUMTYPE_RSA_MD5,
110  				       in_data->data,
111  				       in_data->length,
112  				       &c);
113  	} else {
114  	    krb5_crypto crypto;
115  
116  	    ret = krb5_crypto_init(context, ac->keyblock, 0, &crypto);
117  	    if (ret)
118  		goto out;
119  	    ret = krb5_create_checksum(context,
120  				       crypto,
121  				       checksum_usage,
122  				       0,
123  				       in_data->data,
124  				       in_data->length,
125  				       &c);
126  	    krb5_crypto_destroy(context, crypto);
127  	}
128  	c_opt = &c;
129      } else {
130  	c_opt = NULL;
131      }
132  
133      if (ret)
134  	goto out;
135  
136      ret = _krb5_build_authenticator(context,
137  				    ac,
138  				    ac->keyblock->keytype,
139  				    in_creds,
140  				    c_opt,
141  				    &authenticator,
142  				    encrypt_usage);
143      if (c_opt)
144  	free_Checksum (c_opt);
145      if (ret)
146  	goto out;
147  
148      ret = krb5_build_ap_req(context, ac->keyblock->keytype,
149  			    in_creds, ap_req_options, authenticator, outbuf);
150  out:
151      if(auth_context == NULL)
152  	krb5_auth_con_free(context, ac);
153      return ret;
154  }
155  
156  KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
157  krb5_mk_req_extended(krb5_context context,
158  		     krb5_auth_context *auth_context,
159  		     const krb5_flags ap_req_options,
160  		     krb5_data *in_data,
161  		     krb5_creds *in_creds,
162  		     krb5_data *outbuf)
163  {
164      return _krb5_mk_req_internal(context,
165  				 auth_context,
166  				 ap_req_options,
167  				 in_data,
168  				 NULL,
169  				 in_creds,
170  				 outbuf,
171  				 KRB5_KU_AP_REQ_AUTH_CKSUM,
172  				 KRB5_KU_AP_REQ_AUTH);
173  }