null-auth.c

srtp 1.0.1 比较适用于头一次看。其他版本的有需要也可以传上来。

/*
 * null-auth.c
 *
 * implements the do-nothing auth algorithm
 *
 * David A. McGrew
 * Cisco Systems, Inc.
 *
 */

/*
 *	
 * Copyright  (c) 2001, 2002, Cisco Systems, Inc.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 *   Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 *   Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 * 
 *   Neither the name of the Cisco Systems, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */


#include "null-auth.h" 


err_status_t
null_auth_alloc(auth_t **a, int key_len, int out_len) {
  extern auth_type_t null_auth;
  octet_t *pointer;

  /* allocate memory for auth and null_auth_ctx_t structures */
  pointer = malloc(sizeof(null_auth_ctx_t) + sizeof(auth_t));
  if (pointer == NULL)
    return err_status_alloc_fail;

  /* set pointers */
  *a = (auth_t *)pointer;
  (*a)->type = &null_auth;
  (*a)->state = pointer + sizeof (auth_t);  
  (*a)->out_len = out_len;
  (*a)->key_len = key_len;

  /* increment global count of all null_auth uses */
  null_auth.ref_count++;

  return err_status_ok;
}

err_status_t
null_auth_dealloc(auth_t *a) {
  extern auth_type_t null_auth;
  
  /* free memory */
  free(a);
  
  /* decrement global count of all null_auth uses */
  null_auth.ref_count--;

  return err_status_ok;
}

err_status_t
null_auth_init(null_auth_ctx_t *state, const octet_t *key, int key_len) {

  /* accept any length of key, and do nothing */
  
  return err_status_ok;
}

err_status_t
null_auth_compute (null_auth_ctx_t *state, octet_t *message,
		   int msg_octets, octet_t *result) {

  return err_status_ok;
}

char null_auth_description[] = "null authentication function";

auth_type_t
null_auth  = {
  (auth_alloc_func)      null_auth_alloc,
  (auth_dealloc_func)    null_auth_dealloc,
  (auth_init_func)       null_auth_init,
  (auth_compute_func)    null_auth_compute,
  (char *)               null_auth_description,
  (int)                  0  /* instance count */
};