 59a594bad4
			
		
	
	59a594bad4
	
	
	
		
			
			git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@9559 ec53bebd-3082-4978-b11e-865c3cabbd6b
		
			
				
	
	
		
			272 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			272 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 1997 - 2001 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 "gssapi_locl.h"
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| 
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| RCSID("$Id$");
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| 
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| static OM_uint32
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| verify_mic_des
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|            (OM_uint32 * minor_status,
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|             const gss_ctx_id_t context_handle,
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|             const gss_buffer_t message_buffer,
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|             const gss_buffer_t token_buffer,
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|             gss_qop_t * qop_state,
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| 	    krb5_keyblock *key
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| 	    )
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| {
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|   u_char *p;
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|   MD5_CTX md5;
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|   u_char hash[16], seq_data[8];
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|   des_key_schedule schedule;
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|   des_cblock zero;
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|   des_cblock deskey;
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|   int32_t seq_number;
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|   OM_uint32 ret;
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| 
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|   p = token_buffer->value;
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|   ret = gssapi_krb5_verify_header (&p,
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| 				   token_buffer->length,
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| 				   "\x01\x01");
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|   if (ret)
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|       return ret;
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| 
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|   if (memcmp(p, "\x00\x00", 2) != 0)
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|       return GSS_S_BAD_SIG;
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|   p += 2;
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|   if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
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|     return GSS_S_BAD_MIC;
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|   p += 4;
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|   p += 16;
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| 
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|   /* verify checksum */
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|   MD5_Init (&md5);
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|   MD5_Update (&md5, p - 24, 8);
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|   MD5_Update (&md5, message_buffer->value,
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| 	     message_buffer->length);
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|   MD5_Final (hash, &md5);
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| 
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|   memset (&zero, 0, sizeof(zero));
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|   memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
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| 
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|   des_set_key (&deskey, schedule);
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|   des_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
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| 		 schedule, &zero);
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|   if (memcmp (p - 8, hash, 8) != 0) {
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|     memset (deskey, 0, sizeof(deskey));
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|     memset (schedule, 0, sizeof(schedule));
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|     return GSS_S_BAD_MIC;
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|   }
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| 
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|   /* verify sequence number */
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|   
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|   krb5_auth_getremoteseqnumber (gssapi_krb5_context,
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| 				context_handle->auth_context,
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| 				&seq_number);
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|   seq_data[0] = (seq_number >> 0)  & 0xFF;
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|   seq_data[1] = (seq_number >> 8)  & 0xFF;
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|   seq_data[2] = (seq_number >> 16) & 0xFF;
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|   seq_data[3] = (seq_number >> 24) & 0xFF;
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|   memset (seq_data + 4,
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| 	  (context_handle->more_flags & LOCAL) ? 0xFF : 0,
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| 	  4);
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| 
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|   p -= 16;
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|   des_set_key (&deskey, schedule);
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|   des_cbc_encrypt ((void *)p, (void *)p, 8,
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| 		   schedule, (des_cblock *)hash, DES_DECRYPT);
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| 
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|   memset (deskey, 0, sizeof(deskey));
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|   memset (schedule, 0, sizeof(schedule));
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| 
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|   if (memcmp (p, seq_data, 8) != 0) {
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|     return GSS_S_BAD_MIC;
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|   }
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| 
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|   krb5_auth_setremoteseqnumber (gssapi_krb5_context,
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| 				context_handle->auth_context,
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| 				++seq_number);
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| 
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|   return GSS_S_COMPLETE;
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| }
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| 
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| static OM_uint32
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| verify_mic_des3
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|            (OM_uint32 * minor_status,
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|             const gss_ctx_id_t context_handle,
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|             const gss_buffer_t message_buffer,
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|             const gss_buffer_t token_buffer,
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|             gss_qop_t * qop_state,
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| 	    krb5_keyblock *key
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| 	    )
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| {
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|   u_char *p;
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|   u_char seq[8];
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|   int32_t seq_number;
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|   OM_uint32 ret;
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|   krb5_crypto crypto;
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|   krb5_data seq_data;
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|   int cmp;
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|   Checksum csum;
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|   char *tmp;
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|   
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|   p = token_buffer->value;
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|   ret = gssapi_krb5_verify_header (&p,
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| 				   token_buffer->length,
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| 				   "\x01\x01");
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|   if (ret)
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|       return ret;
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| 
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|   if (memcmp(p, "\x04\x00", 2) != 0) /* SGN_ALG = HMAC SHA1 DES3-KD */
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|       return GSS_S_BAD_SIG;
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|   p += 2;
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|   if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
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|     return GSS_S_BAD_MIC;
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|   p += 4;
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| 
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|   ret = krb5_crypto_init(gssapi_krb5_context, key,
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| 			 ETYPE_DES3_CBC_NONE, &crypto);
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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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|   /* verify sequence number */
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| 
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|   ret = krb5_decrypt (gssapi_krb5_context,
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| 		      crypto,
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| 		      KRB5_KU_USAGE_SEQ,
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| 		      p, 8, &seq_data);
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|   if (ret) {
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|       krb5_crypto_destroy (gssapi_krb5_context, crypto);
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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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|   if (seq_data.length != 8) {
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|       krb5_crypto_destroy (gssapi_krb5_context, crypto);
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|       krb5_data_free (&seq_data);
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|       return GSS_S_BAD_MIC;
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|   }
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| 
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|   krb5_auth_getremoteseqnumber (gssapi_krb5_context,
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| 				context_handle->auth_context,
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| 				&seq_number);
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|   seq[0] = (seq_number >> 0)  & 0xFF;
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|   seq[1] = (seq_number >> 8)  & 0xFF;
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|   seq[2] = (seq_number >> 16) & 0xFF;
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|   seq[3] = (seq_number >> 24) & 0xFF;
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|   memset (seq + 4,
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| 	  (context_handle->more_flags & LOCAL) ? 0xFF : 0,
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| 	  4);
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|   cmp = memcmp (seq, seq_data.data, seq_data.length);
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|   krb5_data_free (&seq_data);
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|   if (cmp != 0) {
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|       krb5_crypto_destroy (gssapi_krb5_context, crypto);
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|       return GSS_S_BAD_MIC;
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|   }
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| 
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|   /* verify checksum */
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| 
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|   tmp = malloc (message_buffer->length + 8);
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|   if (tmp == NULL) {
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|       krb5_crypto_destroy (gssapi_krb5_context, crypto);
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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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|   memcpy (tmp, p - 8, 8);
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|   memcpy (tmp + 8, message_buffer->value, message_buffer->length);
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| 
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|   csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
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|   csum.checksum.length = 20;
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|   csum.checksum.data   = p + 8;
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| 
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|   ret = krb5_verify_checksum (gssapi_krb5_context, crypto,
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| 			      KRB5_KU_USAGE_SIGN,
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| 			      tmp, message_buffer->length + 8,
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| 			      &csum);
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|   free (tmp);
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|   if (ret) {
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|       krb5_crypto_destroy (gssapi_krb5_context, crypto);
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|       *minor_status = ret;
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|       return GSS_S_BAD_MIC;
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|   }
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| 
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|   krb5_auth_setremoteseqnumber (gssapi_krb5_context,
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| 				context_handle->auth_context,
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| 				++seq_number);
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| 
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|   krb5_crypto_destroy (gssapi_krb5_context, crypto);
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|   return GSS_S_COMPLETE;
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| }
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| 
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| OM_uint32
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| gss_verify_mic
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|            (OM_uint32 * minor_status,
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|             const gss_ctx_id_t context_handle,
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|             const gss_buffer_t message_buffer,
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|             const gss_buffer_t token_buffer,
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|             gss_qop_t * qop_state
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| 	    )
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| {
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|     krb5_keyblock *key;
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|     OM_uint32 ret;
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|     krb5_keytype keytype;
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| 
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|     ret = krb5_auth_con_getremotesubkey (gssapi_krb5_context,
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| 					 context_handle->auth_context,
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| 					 &key);
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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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|     krb5_enctype_to_keytype (gssapi_krb5_context, key->keytype, &keytype);
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|     switch (keytype) {
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|     case KEYTYPE_DES :
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| 	ret = verify_mic_des (minor_status, context_handle,
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| 			      message_buffer, token_buffer, qop_state, key);
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| 	break;
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|     case KEYTYPE_DES3 :
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| 	ret = verify_mic_des3 (minor_status, context_handle,
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| 			       message_buffer, token_buffer, qop_state, key);
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| 	break;
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|     default :
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| 	*minor_status = KRB5_PROG_ETYPE_NOSUPP;
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| 	ret = GSS_S_FAILURE;
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| 	break;
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|     }
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|     krb5_free_keyblock (gssapi_krb5_context, key);
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|     return ret;
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| }
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