 a684e001ba
			
		
	
	a684e001ba
	
	
	
		
			
			Our initiator supports configuration-driven delegation of destination
TGTs.
This commit adds acceptor-side handling of destination TGT policy to
reject storing of non-destination TGTs when destination TGTs are
desired.
Currently we use the same appdefault for this.
Background:
    A root TGT is one of the form krbtgt/REALM@SAME-REALM.
    A destination TGT is a root TGT for the same realm as the acceptor
    service's realm.
    Normally clients delegate a root TGT for the client's realm.
    In some deployments clients may want to delegate destination TGTs as
    a form of constrained delegation: so that the destination service
    cannot use the delegated credential to impersonate the client
    principal to services in its home realm (due to KDC lineage/transit
    checks).  In those deployments there may not even be a route back to
    the KDCs of the client's realm, and attempting to use a
    non-destination TGT might even lead to timeouts.
		
	
		
			
				
	
	
		
			280 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			280 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2009 Kungliga Tekniska Högskolan
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|  * (Royal Institute of Technology, Stockholm, Sweden).
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  *
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  *
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *
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|  * 3. Neither the name of the Institute nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #include "gsskrb5_locl.h"
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| 
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| OM_uint32 GSSAPI_CALLCONV
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| _gsskrb5_export_cred(OM_uint32 *minor_status,
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| 		     gss_cred_id_t cred_handle,
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| 		     gss_buffer_t cred_token)
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| {
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|     gsskrb5_cred handle = (gsskrb5_cred)cred_handle;
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|     krb5_context context;
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|     krb5_error_code ret;
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|     krb5_storage *sp;
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|     krb5_data data, mech;
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|     const char *type;
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|     char *str;
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| 
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|     GSSAPI_KRB5_INIT (&context);
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| 
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|     if (handle->usage != GSS_C_INITIATE && handle->usage != GSS_C_BOTH) {
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| 	*minor_status = GSS_KRB5_S_G_BAD_USAGE;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     sp = krb5_storage_emem();
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|     if (sp == NULL) {
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| 	*minor_status = ENOMEM;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     type = krb5_cc_get_type(context, handle->ccache);
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|     if (strcmp(type, "MEMORY") == 0) {
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| 	krb5_creds *creds;
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| 	krb5_data config_start_realm;
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| 	char *start_realm;
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| 
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| 	ret = krb5_store_uint32(sp, 0);
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| 	if (ret) {
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| 	    krb5_storage_free(sp);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_cc_get_config(context, handle->ccache, NULL, "start_realm",
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| 				 &config_start_realm);
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| 	if (ret == 0) {
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| 	    start_realm = strndup(config_start_realm.data,
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| 				  config_start_realm.length);
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| 	    krb5_data_free(&config_start_realm);
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| 	} else {
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| 	    start_realm = strdup(krb5_principal_get_realm(context,
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| 							  handle->principal));
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| 	}
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| 	if (start_realm == NULL) {
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| 	    *minor_status = krb5_enomem(context);
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| 	    krb5_storage_free(sp);
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = _krb5_get_krbtgt(context, handle->ccache, start_realm, &creds);
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| 	free(start_realm);
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| 	start_realm = NULL;
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| 	if (ret) {
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| 	    krb5_storage_free(sp);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_store_creds(sp, creds);
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| 	krb5_free_creds(context, creds);
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| 	if (ret) {
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| 	    krb5_storage_free(sp);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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|     } else {
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| 	ret = krb5_store_uint32(sp, 1);
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| 	if (ret) {
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| 	    krb5_storage_free(sp);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_cc_get_full_name(context, handle->ccache, &str);
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| 	if (ret) {
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| 	    krb5_storage_free(sp);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_store_string(sp, str);
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| 	free(str);
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| 	if (ret) {
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| 	    krb5_storage_free(sp);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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|     }
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|     ret = krb5_storage_to_data(sp, &data);
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|     krb5_storage_free(sp);
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|     if (ret) {
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| 	*minor_status = ret;
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| 	return GSS_S_FAILURE;
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|     }
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|     sp = krb5_storage_emem();
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|     if (sp == NULL) {
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| 	krb5_data_free(&data);
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| 	*minor_status = ENOMEM;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     mech.data = GSS_KRB5_MECHANISM->elements;
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|     mech.length = GSS_KRB5_MECHANISM->length;
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| 
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|     ret = krb5_store_data(sp, mech);
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|     if (ret) {
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| 	krb5_data_free(&data);
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| 	krb5_storage_free(sp);
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| 	*minor_status = ret;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     ret = krb5_store_data(sp, data);
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|     krb5_data_free(&data);
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|     if (ret) {
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| 	krb5_storage_free(sp);
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| 	*minor_status = ret;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     ret = krb5_storage_to_data(sp, &data);
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|     krb5_storage_free(sp);
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|     if (ret) {
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| 	*minor_status = ret;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     cred_token->value = data.data;
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|     cred_token->length = data.length;
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| 
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|     return GSS_S_COMPLETE;
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| }
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| 
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| OM_uint32 GSSAPI_CALLCONV
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| _gsskrb5_import_cred(OM_uint32 * minor_status,
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| 		     gss_buffer_t cred_token,
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| 		     gss_cred_id_t * cred_handle)
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| {
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|     krb5_context context;
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|     krb5_error_code ret;
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|     gsskrb5_cred handle;
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|     krb5_ccache id;
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|     krb5_storage *sp;
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|     char *str;
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|     uint32_t type;
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|     int flags = 0;
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| 
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|     *cred_handle = GSS_C_NO_CREDENTIAL;
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| 
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|     GSSAPI_KRB5_INIT (&context);
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| 
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|     sp = krb5_storage_from_mem(cred_token->value, cred_token->length);
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|     if (sp == NULL) {
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| 	*minor_status = ENOMEM;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     ret = krb5_ret_uint32(sp, &type);
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|     if (ret) {
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| 	krb5_storage_free(sp);
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| 	*minor_status = ret;
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| 	return GSS_S_FAILURE;
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|     }
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|     switch (type) {
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|     case 0: {
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| 	krb5_creds creds;
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| 
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| 	ret = krb5_ret_creds(sp, &creds);
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| 	krb5_storage_free(sp);
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| 	if (ret) {
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_cc_new_unique(context, "MEMORY", NULL, &id);
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| 	if (ret) {
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_cc_initialize(context, id, creds.client);
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| 	if (ret) {
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| 	    krb5_cc_destroy(context, id);
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_cc_store_cred(context, id, &creds);
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| 	krb5_free_cred_contents(context, &creds);
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| 	if (ret) {
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
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| 
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| 	break;
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|     }
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|     case 1:
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| 	ret = krb5_ret_string(sp, &str);
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| 	krb5_storage_free(sp);
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| 	if (ret) {
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 
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| 	ret = krb5_cc_resolve(context, str, &id);
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| 	krb5_xfree(str);
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| 	if (ret) {
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| 	    *minor_status = ret;
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| 	    return GSS_S_FAILURE;
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| 	}
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| 	break;
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| 
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|     default:
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| 	krb5_storage_free(sp);
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| 	*minor_status = 0;
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| 	return GSS_S_NO_CRED;
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|     }
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| 
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|     handle = calloc(1, sizeof(*handle));
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|     if (handle == NULL) {
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| 	krb5_cc_close(context, id);
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| 	*minor_status = ENOMEM;
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| 	return GSS_S_FAILURE;
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|     }
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| 
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|     handle->usage = GSS_C_INITIATE;
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|     handle->destination_realm = NULL;
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|     krb5_cc_get_principal(context, id, &handle->principal);
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|     handle->ccache = id;
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|     handle->cred_flags = flags;
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| 
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|     *cred_handle = (gss_cred_id_t)handle;
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| 
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|     return GSS_S_COMPLETE;
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| }
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