Add current version of libSRTP from CVS.

libsrtp/test/srtp_driver.c

+/*
+ * srtp_driver.c
+ * 
+ * a test driver for libSRTP
+ *
+ * David A. McGrew
+ * Cisco Systems, Inc.
+ */
+/*
+ *      
+ * Copyright (c) 2001-2006, 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 <string.h>   /* for memcpy()          */
+#include <time.h>     /* for clock()           */
+#include <stdlib.h>   /* for malloc(), free()  */
+#include <stdio.h>    /* for print(), fflush() */
+#include "getopt_s.h" /* for local getopt()    */
+
+#include "srtp_priv.h"
+
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#elif defined HAVE_WINSOCK2_H
+# include <winsock2.h>
+#endif
+
+#define PRINT_REFERENCE_PACKET 1
+
+err_status_t
+srtp_validate(void);
+
+err_status_t
+srtp_validate_aes_256(void);
+
+err_status_t
+srtp_create_big_policy(srtp_policy_t **list);
+
+err_status_t
+srtp_dealloc_big_policy(srtp_policy_t *list);
+
+err_status_t
+srtp_test_remove_stream(void);
+
+double
+srtp_bits_per_second(int msg_len_octets, const srtp_policy_t *policy);
+
+double
+srtp_rejections_per_second(int msg_len_octets, const srtp_policy_t *policy);
+
+void
+srtp_do_timing(const srtp_policy_t *policy);
+
+void
+srtp_do_rejection_timing(const srtp_policy_t *policy);
+
+err_status_t
+srtp_test(const srtp_policy_t *policy);
+
+err_status_t
+srtcp_test(const srtp_policy_t *policy);
+
+err_status_t
+srtp_session_print_policy(srtp_t srtp);
+
+err_status_t
+srtp_print_policy(const srtp_policy_t *policy); 
+
+char *
+srtp_packet_to_string(srtp_hdr_t *hdr, int packet_len);
+
+double
+mips_estimate(int num_trials, int *ignore);
+
+extern uint8_t test_key[30];
+
+void
+usage(char *prog_name) {
+  printf("usage: %s [ -t ][ -c ][ -v ][-d <debug_module> ]* [ -l ]\n"
+         "  -t         run timing test\n"
+         "  -r         run rejection timing test\n"
+         "  -c         run codec timing test\n"
+         "  -v         run validation tests\n"
+         "  -d <mod>   turn on debugging module <mod>\n"
+         "  -l         list debugging modules\n", prog_name);
+  exit(1);
+}
+
+/*
+ * The policy_array is a null-terminated array of policy structs. it
+ * is declared at the end of this file
+ */
+
+extern const srtp_policy_t *policy_array[];
+
+
+/* the wildcard_policy is declared below; it has a wildcard ssrc */
+
+extern const srtp_policy_t wildcard_policy;
+
+/*
+ * mod_driver debug module - debugging module for this test driver
+ *
+ * we use the crypto_kernel debugging system in this driver, which 
+ * makes the interface uniform and increases portability
+ */ 
+
+debug_module_t mod_driver = {
+  0,                  /* debugging is off by default */
+  "driver"            /* printable name for module   */
+};
+
+int
+main (int argc, char *argv[]) {
+  int q;
+  unsigned do_timing_test    = 0;
+  unsigned do_rejection_test = 0;
+  unsigned do_codec_timing   = 0;
+  unsigned do_validation     = 0;
+  unsigned do_list_mods      = 0;
+  err_status_t status;
+
+  /* 
+   * verify that the compiler has interpreted the header data
+   * structure srtp_hdr_t correctly
+   */
+  if (sizeof(srtp_hdr_t) != 12) {
+     printf("error: srtp_hdr_t has incorrect size"
+            "(size is %ld bytes, expected 12)\n", 
+            (long)sizeof(srtp_hdr_t));
+    exit(1);
+  }
+
+  /* initialize srtp library */
+  status = srtp_init();
+  if (status) {
+    printf("error: srtp init failed with error code %d\n", status);
+    exit(1);
+  }
+
+  /*  load srtp_driver debug module */
+  status = crypto_kernel_load_debug_module(&mod_driver);
+    if (status) {
+    printf("error: load of srtp_driver debug module failed "
+           "with error code %d\n", status);
+    exit(1);   
+  }
+
+  /* process input arguments */
+  while (1) {
+    q = getopt_s(argc, argv, "trcvld:");
+    if (q == -1) 
+      break;
+    switch (q) {
+    case 't':
+      do_timing_test = 1;
+      break;
+    case 'r':
+      do_rejection_test = 1;
+      break;
+    case 'c':
+      do_codec_timing = 1;
+      break;
+    case 'v':
+      do_validation = 1;
+      break;
+    case 'l':
+      do_list_mods = 1;
+      break;
+    case 'd':
+      status = crypto_kernel_set_debug_module(optarg_s, 1);
+      if (status) {
+        printf("error: set debug module (%s) failed\n", optarg_s);
+        exit(1);
+      }  
+      break;
+    default:
+      usage(argv[0]);
+    }    
+  }
+
+  if (!do_validation && !do_timing_test && !do_codec_timing 
+      && !do_list_mods && !do_rejection_test)
+    usage(argv[0]);
+
+  if (do_list_mods) {
+    status = crypto_kernel_list_debug_modules();
+    if (status) {
+      printf("error: list of debug modules failed\n");
+      exit(1);
+    }
+  }
+  
+  if (do_validation) {
+    const srtp_policy_t **policy = policy_array;
+    srtp_policy_t *big_policy;
+
+    /* loop over policy array, testing srtp and srtcp for each policy */
+    while (*policy != NULL) {
+      printf("testing srtp_protect and srtp_unprotect\n");
+      if (srtp_test(*policy) == err_status_ok)
+        printf("passed\n\n");
+      else {
+        printf("failed\n");
+        exit(1);
+      }
+      printf("testing srtp_protect_rtcp and srtp_unprotect_rtcp\n");
+      if (srtcp_test(*policy) == err_status_ok)
+        printf("passed\n\n");
+      else {
+        printf("failed\n");
+        exit(1);
+      }
+      policy++;
+    }
+
+    /* create a big policy list and run tests on it */
+    status = srtp_create_big_policy(&big_policy);
+    if (status) {
+      printf("unexpected failure with error code %d\n", status);
+      exit(1);
+    }
+    printf("testing srtp_protect and srtp_unprotect with big policy\n");
+    if (srtp_test(big_policy) == err_status_ok)
+      printf("passed\n\n");
+    else {
+      printf("failed\n");
+      exit(1);
+    }
+    status = srtp_dealloc_big_policy(big_policy);
+    if (status) {
+      printf("unexpected failure with error code %d\n", status);
+      exit(1);
+    }
+
+    /* run test on wildcard policy */
+    printf("testing srtp_protect and srtp_unprotect on "
+           "wildcard ssrc policy\n");
+    if (srtp_test(&wildcard_policy) == err_status_ok)
+      printf("passed\n\n");
+    else {
+      printf("failed\n");
+      exit(1);
+    }   
+
+    /*
+     * run validation test against the reference packets - note 
+     * that this test only covers the default policy
+     */
+    printf("testing srtp_protect and srtp_unprotect against "
+           "reference packets\n");
+    if (srtp_validate() == err_status_ok) 
+      printf("passed\n\n");
+    else {
+      printf("failed\n");
+       exit(1); 
+    }
+
+    /*
+     * run validation test against the reference packets for
+     * AES-256
+     */
+    printf("testing srtp_protect and srtp_unprotect against "
+           "reference packets (AES-256)\n");
+    if (srtp_validate_aes_256() == err_status_ok) 
+      printf("passed\n\n");
+    else {
+      printf("failed\n");
+       exit(1); 
+    }
+
+    /*
+     * test the function srtp_remove_stream()
+     */
+    printf("testing srtp_remove_stream()...");
+    if (srtp_test_remove_stream() == err_status_ok)
+      printf("passed\n");
+    else {
+      printf("failed\n");
+      exit(1);
+    }
+  }
+  
+  if (do_timing_test) {
+    const srtp_policy_t **policy = policy_array;
+    
+    /* loop over policies, run timing test for each */
+    while (*policy != NULL) {
+      srtp_print_policy(*policy);
+      srtp_do_timing(*policy);
+      policy++;
+    }
+  }
+
+  if (do_rejection_test) {
+    const srtp_policy_t **policy = policy_array;
+    
+    /* loop over policies, run rejection timing test for each */
+    while (*policy != NULL) {
+      srtp_print_policy(*policy);
+      srtp_do_rejection_timing(*policy);
+      policy++;
+    }
+  }
+  
+  if (do_codec_timing) {
+    srtp_policy_t policy;
+    int ignore;
+    double mips = mips_estimate(1000000000, &ignore);
+
+    crypto_policy_set_rtp_default(&policy.rtp);
+    crypto_policy_set_rtcp_default(&policy.rtcp);
+    policy.ssrc.type  = ssrc_specific;
+    policy.ssrc.value = 0xdecafbad;
+    policy.key  = test_key;
+    policy.ekt = NULL;
+    policy.window_size = 128;
+    policy.allow_repeat_tx = 0;
+    policy.next = NULL;
+
+    printf("mips estimate: %e\n", mips);
+
+    printf("testing srtp processing time for voice codecs:\n");
+    printf("codec\t\tlength (octets)\t\tsrtp instructions/second\n");
+    printf("G.711\t\t%d\t\t\t%e\n", 80, 
+           (double) mips * (80 * 8) / 
+           srtp_bits_per_second(80, &policy) / .01 );
+    printf("G.711\t\t%d\t\t\t%e\n", 160, 
+           (double) mips * (160 * 8) / 
+           srtp_bits_per_second(160, &policy) / .02);
+    printf("G.726-32\t%d\t\t\t%e\n", 40, 
+           (double) mips * (40 * 8) / 
+           srtp_bits_per_second(40, &policy) / .01 );
+    printf("G.726-32\t%d\t\t\t%e\n", 80, 
+           (double) mips * (80 * 8) / 
+           srtp_bits_per_second(80, &policy) / .02);
+    printf("G.729\t\t%d\t\t\t%e\n", 10, 
+           (double) mips * (10 * 8) / 
+           srtp_bits_per_second(10, &policy) / .01 );
+    printf("G.729\t\t%d\t\t\t%e\n", 20, 
+           (double) mips * (20 * 8) /
+           srtp_bits_per_second(20, &policy) / .02 );
+    printf("Wideband\t%d\t\t\t%e\n", 320, 
+           (double) mips * (320 * 8) /
+           srtp_bits_per_second(320, &policy) / .01 );
+    printf("Wideband\t%d\t\t\t%e\n", 640, 
+           (double) mips * (640 * 8) /
+           srtp_bits_per_second(640, &policy) / .02 );
+  }
+
+  status = srtp_shutdown();
+  if (status) {
+    printf("error: srtp shutdown failed with error code %d\n", status);
+    exit(1);
+  }
+
+  return 0;  
+}
+
+
+
+/*
+ * srtp_create_test_packet(len, ssrc) returns a pointer to a
+ * (malloced) example RTP packet whose data field has the length given
+ * by pkt_octet_len and the SSRC value ssrc.  The total length of the
+ * packet is twelve octets longer, since the header is at the
+ * beginning.  There is room at the end of the packet for a trailer,
+ * and the four octets following the packet are filled with 0xff
+ * values to enable testing for overwrites.
+ *
+ * note that the location of the test packet can (and should) be
+ * deallocated with the free() call once it is no longer needed.
+ */
+
+srtp_hdr_t *
+srtp_create_test_packet(int pkt_octet_len, uint32_t ssrc) {
+  int i;
+  uint8_t *buffer;
+  srtp_hdr_t *hdr;
+  int bytes_in_hdr = 12;
+
+  /* allocate memory for test packet */
+  hdr = (srtp_hdr_t*) malloc(pkt_octet_len + bytes_in_hdr
+               + SRTP_MAX_TRAILER_LEN + 4);
+  if (!hdr)
+    return NULL;
+  
+  hdr->version = 2;              /* RTP version two     */
+  hdr->p    = 0;                 /* no padding needed   */
+  hdr->x    = 0;                 /* no header extension */
+  hdr->cc   = 0;                 /* no CSRCs            */
+  hdr->m    = 0;                 /* marker bit          */
+  hdr->pt   = 0xf;               /* payload type        */
+  hdr->seq  = htons(0x1234);     /* sequence number     */
+  hdr->ts   = htonl(0xdecafbad); /* timestamp           */
+  hdr->ssrc = htonl(ssrc);       /* synch. source       */
+
+  buffer = (uint8_t *)hdr;
+  buffer += bytes_in_hdr;
+
+  /* set RTP data to 0xab */
+  for (i=0; i < pkt_octet_len; i++)
+    *buffer++ = 0xab;
+
+  /* set post-data value to 0xffff to enable overrun checking */
+  for (i=0; i < SRTP_MAX_TRAILER_LEN+4; i++)
+    *buffer++ = 0xff;
+
+  return hdr;
+}
+
+void
+srtp_do_timing(const srtp_policy_t *policy) {
+  int len;
+
+  /*
+   * note: the output of this function is formatted so that it
+   * can be used in gnuplot.  '#' indicates a comment, and "\r\n"
+   * terminates a record
+   */
+  
+  printf("# testing srtp throughput:\r\n");
+  printf("# mesg length (octets)\tthroughput (megabits per second)\r\n");
+  
+  for (len=16; len <= 2048; len *= 2)
+    printf("%d\t\t\t%f\r\n", len, 
+           srtp_bits_per_second(len, policy) / 1.0E6);
+  
+  /* these extra linefeeds let gnuplot know that a dataset is done */
+  printf("\r\n\r\n");  
+
+}
+
+void
+srtp_do_rejection_timing(const srtp_policy_t *policy) {
+  int len;
+
+  /*
+   * note: the output of this function is formatted so that it
+   * can be used in gnuplot.  '#' indicates a comment, and "\r\n"
+   * terminates a record
+   */
+  
+  printf("# testing srtp rejection throughput:\r\n");
+  printf("# mesg length (octets)\trejections per second\r\n");
+  
+  for (len=8; len <= 2048; len *= 2)
+    printf("%d\t\t\t%e\r\n", len, srtp_rejections_per_second(len, policy));
+  
+  /* these extra linefeeds let gnuplot know that a dataset is done */
+  printf("\r\n\r\n");  
+
+}
+
+
+#define MAX_MSG_LEN 1024
+
+double
+srtp_bits_per_second(int msg_len_octets, const srtp_policy_t *policy) {
+  srtp_t srtp;
+  srtp_hdr_t *mesg;  
+  int i;
+  clock_t timer;
+  int num_trials = 100000;
+  int len;
+  uint32_t ssrc;
+  err_status_t status;
+
+  /*
+   * allocate and initialize an srtp session
+   */
+  status = srtp_create(&srtp, policy);
+  if (status) {
+    printf("error: srtp_create() failed with error code %d\n", status);
+    exit(1);
+  }
+
+  /*
+   * if the ssrc is unspecified, use a predetermined one
+   */
+  if (policy->ssrc.type != ssrc_specific) {
+    ssrc = 0xdeadbeef;
+  } else {
+    ssrc = policy->ssrc.value;
+  }
+
+  /*
+   * create a test packet
+   */
+  mesg = srtp_create_test_packet(msg_len_octets, ssrc);
+  if (mesg == NULL)
+    return 0.0;   /* indicate failure by returning zero */
+  
+  timer = clock();
+  for (i=0; i < num_trials; i++) {
+    len = msg_len_octets + 12;  /* add in rtp header length */
+    
+    /* srtp protect message */
+    status = srtp_protect(srtp, mesg, &len);
+    if (status) {
+      printf("error: srtp_protect() failed with error code %d\n", status);
+      exit(1);
+    }
+
+    /* increment message number */
+    {
+      /* hack sequence to avoid problems with macros for htons/ntohs on some systems */
+      short new_seq = ntohs(mesg->seq) + 1;
+      mesg->seq = htons(new_seq);
+    }
+  }
+  timer = clock() - timer;
+
+  free(mesg);
+
+  status = srtp_dealloc(srtp);
+  if (status) {
+    printf("error: srtp_dealloc() failed with error code %d\n", status);
+    exit(1);
+  }
+  
+  return (double) (msg_len_octets) * 8 *
+                  num_trials * CLOCKS_PER_SEC / timer;   
+}
+
+double
+srtp_rejections_per_second(int msg_len_octets, const srtp_policy_t *policy) {
+  srtp_ctx_t *srtp;
+  srtp_hdr_t *mesg; 
+  int i;
+  int len;
+  clock_t timer;
+  int num_trials = 1000000;
+  uint32_t ssrc = policy->ssrc.value;
+  err_status_t status;
+
+  /*
+   * allocate and initialize an srtp session
+   */
+  status = srtp_create(&srtp, policy);
+  if (status) {
+    printf("error: srtp_create() failed with error code %d\n", status);
+    exit(1);
+  } 
+
+  mesg = srtp_create_test_packet(msg_len_octets, ssrc);
+  if (mesg == NULL)
+    return 0.0;  /* indicate failure by returning zero */
+  
+  len = msg_len_octets;  
+  srtp_protect(srtp, (srtp_hdr_t *)mesg, &len);
+  
+  timer = clock();
+  for (i=0; i < num_trials; i++) {
+    len = msg_len_octets;
+    srtp_unprotect(srtp, (srtp_hdr_t *)mesg, &len);
+  }
+  timer = clock() - timer;
+
+  free(mesg);
+
+  status = srtp_dealloc(srtp);
+  if (status) {
+    printf("error: srtp_dealloc() failed with error code %d\n", status);
+    exit(1);
+  }
+
+  return (double) num_trials * CLOCKS_PER_SEC / timer;   
+}
+
+
+void
+err_check(err_status_t s) {
+  if (s == err_status_ok) 
+    return;
+  else
+    fprintf(stderr, "error: unexpected srtp failure (code %d)\n", s);
+  exit (1);
+}
+
+err_status_t
+srtp_test(const srtp_policy_t *policy) {
+  int i;
+  srtp_t srtp_sender;
+  srtp_t srtp_rcvr;
+  err_status_t status = err_status_ok;
+  srtp_hdr_t *hdr, *hdr2;
+  uint8_t hdr_enc[64];
+  uint8_t *pkt_end;
+  int msg_len_octets, msg_len_enc;
+  int len;
+  int tag_length = policy->rtp.auth_tag_len; 
+  uint32_t ssrc;
+  srtp_policy_t *rcvr_policy;
+
+  err_check(srtp_create(&srtp_sender, policy));
+
+  /* print out policy */
+  err_check(srtp_session_print_policy(srtp_sender)); 
+
+  /*
+   * initialize data buffer, using the ssrc in the policy unless that
+   * value is a wildcard, in which case we'll just use an arbitrary
+   * one
+   */
+  if (policy->ssrc.type != ssrc_specific)
+    ssrc = 0xdecafbad;
+  else
+    ssrc = policy->ssrc.value;
+  msg_len_octets = 28;
+  hdr = srtp_create_test_packet(msg_len_octets, ssrc);
+
+  if (hdr == NULL)
+    return err_status_alloc_fail;
+  hdr2 = srtp_create_test_packet(msg_len_octets, ssrc);
+  if (hdr2 == NULL) {
+    free(hdr);
+    return err_status_alloc_fail;
+  }
+
+  /* set message length */
+  len = msg_len_octets;
+
+  debug_print(mod_driver, "before protection:\n%s",           
+              srtp_packet_to_string(hdr, len));
+
+#if PRINT_REFERENCE_PACKET
+  debug_print(mod_driver, "reference packet before protection:\n%s",          
+              octet_string_hex_string((uint8_t *)hdr, len));
+#endif
+  err_check(srtp_protect(srtp_sender, hdr, &len));
+
+  debug_print(mod_driver, "after protection:\n%s",            
+              srtp_packet_to_string(hdr, len));
+#if PRINT_REFERENCE_PACKET
+  debug_print(mod_driver, "after protection:\n%s",            
+              octet_string_hex_string((uint8_t *)hdr, len));
+#endif
+
+  /* save protected message and length */
+  memcpy(hdr_enc, hdr, len);
+  msg_len_enc = len;
+
+  /* 
+   * check for overrun of the srtp_protect() function
+   *
+   * The packet is followed by a value of 0xfffff; if the value of the
+   * data following the packet is different, then we know that the
+   * protect function is overwriting the end of the packet.
+   */
+  pkt_end = (uint8_t *)hdr + sizeof(srtp_hdr_t) 
+    + msg_len_octets + tag_length;
+  for (i = 0; i < 4; i++)
+    if (pkt_end[i] != 0xff) {
+      fprintf(stdout, "overwrite in srtp_protect() function "
+              "(expected %x, found %x in trailing octet %d)\n",
+              0xff, ((uint8_t *)hdr)[i], i);
+      free(hdr);
+      free(hdr2);
+      return err_status_algo_fail;
+    }  
+
+  /*
+   * if the policy includes confidentiality, check that ciphertext is
+   * different than plaintext
+   * 
+   * Note that this check will give false negatives, with some small
+   * probability, especially if the packets are short.  For that
+   * reason, we skip this check if the plaintext is less than four
+   * octets long.
+   */
+  if ((policy->rtp.sec_serv & sec_serv_conf) && (msg_len_octets >= 4)) {
+    printf("testing that ciphertext is distinct from plaintext...");
+    status = err_status_algo_fail;
+    for (i=12; i < msg_len_octets+12; i++)
+      if (((uint8_t *)hdr)[i] != ((uint8_t *)hdr2)[i]) {
+        status = err_status_ok;
+      }
+    if (status) {
+      printf("failed\n");
+      free(hdr);
+      free(hdr2);
+      return status;
+    }
+    printf("passed\n");
+  }
+  
+  /*
+   * if the policy uses a 'wildcard' ssrc, then we need to make a copy
+   * of the policy that changes the direction to inbound
+   *
+   * we always copy the policy into the rcvr_policy, since otherwise
+   * the compiler would fret about the constness of the policy
+   */
+  rcvr_policy = (srtp_policy_t*) malloc(sizeof(srtp_policy_t));
+  if (rcvr_policy == NULL) {
+    free(hdr);
+    free(hdr2);
+    return err_status_alloc_fail;
+  }
+  memcpy(rcvr_policy, policy, sizeof(srtp_policy_t));
+  if (policy->ssrc.type == ssrc_any_outbound) {
+    rcvr_policy->ssrc.type = ssrc_any_inbound;       
+  } 
+
+  err_check(srtp_create(&srtp_rcvr, rcvr_policy));
+   
+  err_check(srtp_unprotect(srtp_rcvr, hdr, &len));
+
+  debug_print(mod_driver, "after unprotection:\n%s",          
+              srtp_packet_to_string(hdr, len));
+
+  /* verify that the unprotected packet matches the origial one */
+  for (i=0; i < msg_len_octets; i++)
+    if (((uint8_t *)hdr)[i] != ((uint8_t *)hdr2)[i]) {
+      fprintf(stdout, "mismatch at octet %d\n", i);
+      status = err_status_algo_fail;
+    }
+  if (status) {
+    free(hdr);
+    free(hdr2);
+    free(rcvr_policy);
+    return status;
+  }
+
+  /* 
+   * if the policy includes authentication, then test for false positives
+   */  
+  if (policy->rtp.sec_serv & sec_serv_auth) {
+    char *data = ((char *)hdr) + 12;
+    
+    printf("testing for false positives in replay check...");
+
+    /* set message length */
+    len = msg_len_enc;
+
+    /* unprotect a second time - should fail with a replay error */
+    status = srtp_unprotect(srtp_rcvr, hdr_enc, &len);
+    if (status != err_status_replay_fail) {
+      printf("failed with error code %d\n", status);
+      free(hdr); 
+      free(hdr2);
+      free(rcvr_policy);
+      return status;
+    } else {
+      printf("passed\n");
+    }
+
+    printf("testing for false positives in auth check...");
+
+    /* increment sequence number in header */
+    hdr->seq++; 
+
+    /* set message length */
+    len = msg_len_octets;
+
+    /* apply protection */
+    err_check(srtp_protect(srtp_sender, hdr, &len));
+    
+    /* flip bits in packet */
+    data[0] ^= 0xff;
+
+    /* unprotect, and check for authentication failure */
+    status = srtp_unprotect(srtp_rcvr, hdr, &len);
+    if (status != err_status_auth_fail) {
+      printf("failed\n");
+      free(hdr); 
+      free(hdr2);
+      free(rcvr_policy);
+      return status;
+    } else {
+      printf("passed\n");
+    }
+            
+  }
+
+  err_check(srtp_dealloc(srtp_sender));
+  err_check(srtp_dealloc(srtp_rcvr));
+
+  free(hdr);
+  free(hdr2);
+  free(rcvr_policy);
+  return err_status_ok;
+}
+
+
+err_status_t
+srtcp_test(const srtp_policy_t *policy) {
+  int i;
+  srtp_t srtcp_sender;
+  srtp_t srtcp_rcvr;
+  err_status_t status = err_status_ok;
+  srtp_hdr_t *hdr, *hdr2;
+  uint8_t hdr_enc[64];
+  uint8_t *pkt_end;
+  int msg_len_octets, msg_len_enc;
+  int len;
+  int tag_length = policy->rtp.auth_tag_len; 
+  uint32_t ssrc;
+  srtp_policy_t *rcvr_policy;
+
+  err_check(srtp_create(&srtcp_sender, policy));
+
+  /* print out policy */
+  err_check(srtp_session_print_policy(srtcp_sender)); 
+
+  /*
+   * initialize data buffer, using the ssrc in the policy unless that
+   * value is a wildcard, in which case we'll just use an arbitrary
+   * one
+   */
+  if (policy->ssrc.type != ssrc_specific)
+    ssrc = 0xdecafbad;
+  else
+    ssrc = policy->ssrc.value;
+  msg_len_octets = 28;
+  hdr = srtp_create_test_packet(msg_len_octets, ssrc);
+
+  if (hdr == NULL)
+    return err_status_alloc_fail;
+  hdr2 = srtp_create_test_packet(msg_len_octets, ssrc);
+  if (hdr2 == NULL) {
+    free(hdr);
+    return err_status_alloc_fail;
+  }
+
+  /* set message length */
+  len = msg_len_octets;
+
+  debug_print(mod_driver, "before protection:\n%s",           
+              srtp_packet_to_string(hdr, len));
+
+#if PRINT_REFERENCE_PACKET
+  debug_print(mod_driver, "reference packet before protection:\n%s",          
+              octet_string_hex_string((uint8_t *)hdr, len));
+#endif
+  err_check(srtp_protect_rtcp(srtcp_sender, hdr, &len));
+
+  debug_print(mod_driver, "after protection:\n%s",            
+              srtp_packet_to_string(hdr, len));
+#if PRINT_REFERENCE_PACKET
+  debug_print(mod_driver, "after protection:\n%s",            
+              octet_string_hex_string((uint8_t *)hdr, len));
+#endif
+
+  /* save protected message and length */
+  memcpy(hdr_enc, hdr, len);
+  msg_len_enc = len;
+
+  /* 
+   * check for overrun of the srtp_protect() function
+   *
+   * The packet is followed by a value of 0xfffff; if the value of the
+   * data following the packet is different, then we know that the
+   * protect function is overwriting the end of the packet.
+   */
+  pkt_end = (uint8_t *)hdr + sizeof(srtp_hdr_t) 
+    + msg_len_octets + tag_length;
+  for (i = 0; i < 4; i++)
+    if (pkt_end[i] != 0xff) {
+      fprintf(stdout, "overwrite in srtp_protect_rtcp() function "
+              "(expected %x, found %x in trailing octet %d)\n",
+              0xff, ((uint8_t *)hdr)[i], i);
+      free(hdr);
+      free(hdr2);
+      return err_status_algo_fail;
+    }  
+
+  /*
+   * if the policy includes confidentiality, check that ciphertext is
+   * different than plaintext
+   * 
+   * Note that this check will give false negatives, with some small
+   * probability, especially if the packets are short.  For that
+   * reason, we skip this check if the plaintext is less than four
+   * octets long.
+   */
+  if ((policy->rtp.sec_serv & sec_serv_conf) && (msg_len_octets >= 4)) {
+    printf("testing that ciphertext is distinct from plaintext...");
+    status = err_status_algo_fail;
+    for (i=12; i < msg_len_octets+12; i++)
+      if (((uint8_t *)hdr)[i] != ((uint8_t *)hdr2)[i]) {
+        status = err_status_ok;
+      }
+    if (status) {
+      printf("failed\n");
+      free(hdr);
+      free(hdr2);
+      return status;
+    }
+    printf("passed\n");
+  }
+  
+  /*
+   * if the policy uses a 'wildcard' ssrc, then we need to make a copy
+   * of the policy that changes the direction to inbound
+   *
+   * we always copy the policy into the rcvr_policy, since otherwise
+   * the compiler would fret about the constness of the policy
+   */
+  rcvr_policy = (srtp_policy_t*) malloc(sizeof(srtp_policy_t));
+  if (rcvr_policy == NULL)
+    return err_status_alloc_fail;
+  memcpy(rcvr_policy, policy, sizeof(srtp_policy_t));
+  if (policy->ssrc.type == ssrc_any_outbound) {
+    rcvr_policy->ssrc.type = ssrc_any_inbound;       
+  } 
+
+  err_check(srtp_create(&srtcp_rcvr, rcvr_policy));
+   
+  err_check(srtp_unprotect_rtcp(srtcp_rcvr, hdr, &len));
+
+  debug_print(mod_driver, "after unprotection:\n%s",          
+              srtp_packet_to_string(hdr, len));
+
+  /* verify that the unprotected packet matches the origial one */
+  for (i=0; i < msg_len_octets; i++)
+    if (((uint8_t *)hdr)[i] != ((uint8_t *)hdr2)[i]) {
+      fprintf(stdout, "mismatch at octet %d\n", i);
+      status = err_status_algo_fail;
+    }
+  if (status) {
+    free(hdr);
+    free(hdr2);
+    free(rcvr_policy);
+    return status;
+  }
+
+  /* 
+   * if the policy includes authentication, then test for false positives
+   */  
+  if (policy->rtp.sec_serv & sec_serv_auth) {
+    char *data = ((char *)hdr) + 12;
+    
+    printf("testing for false positives in replay check...");
+
+    /* set message length */
+    len = msg_len_enc;
+
+    /* unprotect a second time - should fail with a replay error */
+    status = srtp_unprotect_rtcp(srtcp_rcvr, hdr_enc, &len);
+    if (status != err_status_replay_fail) {
+      printf("failed with error code %d\n", status);
+      free(hdr); 
+      free(hdr2);
+      free(rcvr_policy);
+      return status;
+    } else {
+      printf("passed\n");
+    }
+
+    printf("testing for false positives in auth check...");
+
+    /* increment sequence number in header */
+    hdr->seq++; 
+
+    /* set message length */
+    len = msg_len_octets;
+
+    /* apply protection */
+    err_check(srtp_protect_rtcp(srtcp_sender, hdr, &len));
+    
+    /* flip bits in packet */
+    data[0] ^= 0xff;
+
+    /* unprotect, and check for authentication failure */
+    status = srtp_unprotect_rtcp(srtcp_rcvr, hdr, &len);
+    if (status != err_status_auth_fail) {
+      printf("failed\n");
+      free(hdr); 
+      free(hdr2);
+      free(rcvr_policy);
+      return status;
+    } else {
+      printf("passed\n");
+    }
+            
+  }
+
+  err_check(srtp_dealloc(srtcp_sender));
+  err_check(srtp_dealloc(srtcp_rcvr));
+
+  free(hdr);
+  free(hdr2);
+  free(rcvr_policy);
+  return err_status_ok;
+}
+
+
+err_status_t
+srtp_session_print_policy(srtp_t srtp) {
+  char *serv_descr[4] = {
+    "none",
+    "confidentiality",
+    "authentication",
+    "confidentiality and authentication"
+  };
+  char *direction[3] = {
+    "unknown",
+    "outbound",
+    "inbound"
+  };
+  srtp_stream_t stream;
+
+  /* sanity checking */
+  if (srtp == NULL)
+    return err_status_fail;
+
+  /* if there's a template stream, print it out */
+  if (srtp->stream_template != NULL) {
+    stream = srtp->stream_template;
+    printf("# SSRC:          any %s\r\n"
+           "# rtp cipher:    %s\r\n"
+           "# rtp auth:      %s\r\n"
+           "# rtp services:  %s\r\n" 
+           "# rtcp cipher:   %s\r\n"
+           "# rtcp auth:     %s\r\n"
+           "# rtcp services: %s\r\n"
+           "# window size:   %lu\r\n"
+           "# tx rtx allowed:%s\r\n",
+           direction[stream->direction],
+           stream->rtp_cipher->type->description,
+           stream->rtp_auth->type->description,
+           serv_descr[stream->rtp_services],
+           stream->rtcp_cipher->type->description,
+           stream->rtcp_auth->type->description,
+           serv_descr[stream->rtcp_services],
+           rdbx_get_window_size(&stream->rtp_rdbx),
+           stream->allow_repeat_tx ? "true" : "false");
+  }
+
+  /* loop over streams in session, printing the policy of each */
+  stream = srtp->stream_list;
+  while (stream != NULL) {
+    if (stream->rtp_services > sec_serv_conf_and_auth)
+      return err_status_bad_param;
+    
+    printf("# SSRC:          0x%08x\r\n"
+           "# rtp cipher:    %s\r\n"
+           "# rtp auth:      %s\r\n"
+           "# rtp services:  %s\r\n" 
+           "# rtcp cipher:   %s\r\n"
+           "# rtcp auth:     %s\r\n"
+           "# rtcp services: %s\r\n"
+           "# window size:   %lu\r\n"
+           "# tx rtx allowed:%s\r\n",
+           stream->ssrc,
+           stream->rtp_cipher->type->description,
+           stream->rtp_auth->type->description,
+           serv_descr[stream->rtp_services],
+           stream->rtcp_cipher->type->description,
+           stream->rtcp_auth->type->description,
+           serv_descr[stream->rtcp_services],
+           rdbx_get_window_size(&stream->rtp_rdbx),
+           stream->allow_repeat_tx ? "true" : "false");
+
+    /* advance to next stream in the list */
+    stream = stream->next;
+  } 
+  return err_status_ok;
+}
+
+err_status_t
+srtp_print_policy(const srtp_policy_t *policy) {
+  err_status_t status;
+  srtp_t session;
+
+  status = srtp_create(&session, policy);
+  if (status)
+    return status;
+  status = srtp_session_print_policy(session);
+  if (status)
+    return status;
+  status = srtp_dealloc(session);
+  if (status)
+    return status;
+  return err_status_ok;
+}
+
+/* 
+ * srtp_print_packet(...) is for debugging only 
+ * it prints an RTP packet to the stdout
+ *
+ * note that this function is *not* threadsafe
+ */
+
+#include <stdio.h>
+
+#define MTU 2048
+
+char packet_string[MTU];
+
+char *
+srtp_packet_to_string(srtp_hdr_t *hdr, int pkt_octet_len) {
+  int octets_in_rtp_header = 12;
+  uint8_t *data = ((uint8_t *)hdr)+octets_in_rtp_header;
+  int hex_len = pkt_octet_len-octets_in_rtp_header;
+
+  /* sanity checking */
+  if ((hdr == NULL) || (pkt_octet_len > MTU))
+    return NULL;
+
+  /* write packet into string */
+  sprintf(packet_string, 
+          "(s)rtp packet: {\n"
+          "   version:\t%d\n" 
+          "   p:\t\t%d\n"     
+          "   x:\t\t%d\n"     
+          "   cc:\t\t%d\n"    
+          "   m:\t\t%d\n"     
+          "   pt:\t\t%x\n"    
+          "   seq:\t\t%x\n"   
+          "   ts:\t\t%x\n"    
+          "   ssrc:\t%x\n"    
+          "   data:\t%s\n"    
+          "} (%d octets in total)\n", 
+          hdr->version,  
+          hdr->p,              
+          hdr->x,              
+          hdr->cc,       
+          hdr->m,              
+          hdr->pt,       
+          hdr->seq,      
+          hdr->ts,       
+          hdr->ssrc,      
+          octet_string_hex_string(data, hex_len),
+          pkt_octet_len);
+
+  return packet_string;
+}
+
+/*
+ * mips_estimate() is a simple function to estimate the number of
+ * instructions per second that the host can perform.  note that this
+ * function can be grossly wrong; you may want to have a manual sanity
+ * check of its output!
+ *
+ * the 'ignore' pointer is there to convince the compiler to not just
+ * optimize away the function
+ */
+
+double
+mips_estimate(int num_trials, int *ignore) {
+  clock_t t;
+  volatile int i, sum;
+
+  sum = 0;
+  t = clock();
+  for (i=0; i<num_trials; i++)
+    sum += i;
+  t = clock() - t;
+
+/*   printf("%d\n", sum); */
+  *ignore = sum;
+
+  return (double) num_trials * CLOCKS_PER_SEC / t;
+}
+
+
+/*
+ * srtp_validate() verifies the correctness of libsrtp by comparing
+ * some computed packets against some pre-computed reference values.
+ * These packets were made with the default SRTP policy.
+ */
+
+
+err_status_t
+srtp_validate() {
+  uint8_t srtp_plaintext_ref[28] = {
+    0x80, 0x0f, 0x12, 0x34, 0xde, 0xca, 0xfb, 0xad, 
+    0xca, 0xfe, 0xba, 0xbe, 0xab, 0xab, 0xab, 0xab,
+    0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 
+    0xab, 0xab, 0xab, 0xab
+  };
+  uint8_t srtp_plaintext[38] = {
+    0x80, 0x0f, 0x12, 0x34, 0xde, 0xca, 0xfb, 0xad, 
+    0xca, 0xfe, 0xba, 0xbe, 0xab, 0xab, 0xab, 0xab,
+    0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 
+    0xab, 0xab, 0xab, 0xab, 0x00, 0x00, 0x00, 0x00, 
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+  };
+  uint8_t srtp_ciphertext[38] = {
+    0x80, 0x0f, 0x12, 0x34, 0xde, 0xca, 0xfb, 0xad, 
+    0xca, 0xfe, 0xba, 0xbe, 0x4e, 0x55, 0xdc, 0x4c,
+    0xe7, 0x99, 0x78, 0xd8, 0x8c, 0xa4, 0xd2, 0x15, 
+    0x94, 0x9d, 0x24, 0x02, 0xb7, 0x8d, 0x6a, 0xcc,
+    0x99, 0xea, 0x17, 0x9b, 0x8d, 0xbb
+  };
+  srtp_t srtp_snd, srtp_recv;
+  err_status_t status;
+  int len;
+  srtp_policy_t policy;
+  
+  /*
+   * create a session with a single stream using the default srtp
+   * policy and with the SSRC value 0xcafebabe
+   */
+  crypto_policy_set_rtp_default(&policy.rtp);
+  crypto_policy_set_rtcp_default(&policy.rtcp);
+  policy.ssrc.type  = ssrc_specific;
+  policy.ssrc.value = 0xcafebabe;
+  policy.key  = test_key;
+  policy.ekt = NULL;
+  policy.window_size = 128;
+  policy.allow_repeat_tx = 0;
+  policy.next = NULL;
+
+  status = srtp_create(&srtp_snd, &policy);
+  if (status)
+    return status;
+ 
+  /* 
+   * protect plaintext, then compare with ciphertext 
+   */
+  len = 28;
+  status = srtp_protect(srtp_snd, srtp_plaintext, &len);
+  if (status || (len != 38))
+    return err_status_fail;
+
+  debug_print(mod_driver, "ciphertext:\n  %s",        
+              octet_string_hex_string(srtp_plaintext, len));
+  debug_print(mod_driver, "ciphertext reference:\n  %s",              
+              octet_string_hex_string(srtp_ciphertext, len));
+
+  if (octet_string_is_eq(srtp_plaintext, srtp_ciphertext, len))
+    return err_status_fail;
+  
+  /*
+   * create a receiver session context comparable to the one created
+   * above - we need to do this so that the replay checking doesn't
+   * complain
+   */
+  status = srtp_create(&srtp_recv, &policy);
+  if (status)
+    return status;
+
+  /*
+   * unprotect ciphertext, then compare with plaintext 
+   */
+  status = srtp_unprotect(srtp_recv, srtp_ciphertext, &len);
+  if (status || (len != 28))
+    return status;
+  
+  if (octet_string_is_eq(srtp_ciphertext, srtp_plaintext_ref, len))
+    return err_status_fail;
+
+  status = srtp_dealloc(srtp_snd);
+  if (status)
+    return status;
+
+  status = srtp_dealloc(srtp_recv);
+  if (status)
+    return status;
+
+  return err_status_ok;
+}
+
+
+/*
+ * srtp_validate_aes_256() verifies the correctness of libsrtp by comparing
+ * some computed packets against some pre-computed reference values.
+ * These packets were made with the AES-CM-256/HMAC-SHA-1-80 policy.
+ */
+
+
+err_status_t
+srtp_validate_aes_256() {
+  unsigned char aes_256_test_key[46] = {
+    0xf0, 0xf0, 0x49, 0x14, 0xb5, 0x13, 0xf2, 0x76,
+    0x3a, 0x1b, 0x1f, 0xa1, 0x30, 0xf1, 0x0e, 0x29,
+    0x98, 0xf6, 0xf6, 0xe4, 0x3e, 0x43, 0x09, 0xd1,
+    0xe6, 0x22, 0xa0, 0xe3, 0x32, 0xb9, 0xf1, 0xb6,
+
+    0x3b, 0x04, 0x80, 0x3d, 0xe5, 0x1e, 0xe7, 0xc9,
+    0x64, 0x23, 0xab, 0x5b, 0x78, 0xd2
+  };
+  uint8_t srtp_plaintext_ref[28] = {
+    0x80, 0x0f, 0x12, 0x34, 0xde, 0xca, 0xfb, 0xad, 
+    0xca, 0xfe, 0xba, 0xbe, 0xab, 0xab, 0xab, 0xab,
+    0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 
+    0xab, 0xab, 0xab, 0xab
+  };
+  uint8_t srtp_plaintext[38] = {
+    0x80, 0x0f, 0x12, 0x34, 0xde, 0xca, 0xfb, 0xad, 
+    0xca, 0xfe, 0xba, 0xbe, 0xab, 0xab, 0xab, 0xab,
+    0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 
+    0xab, 0xab, 0xab, 0xab, 0x00, 0x00, 0x00, 0x00, 
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+  };
+  uint8_t srtp_ciphertext[38] = {
+    0x80, 0x0f, 0x12, 0x34, 0xde, 0xca, 0xfb, 0xad, 
+    0xca, 0xfe, 0xba, 0xbe, 0xf1, 0xd9, 0xde, 0x17, 
+    0xff, 0x25, 0x1f, 0xf1, 0xaa, 0x00, 0x77, 0x74, 
+    0xb0, 0xb4, 0xb4, 0x0d, 0xa0, 0x8d, 0x9d, 0x9a, 
+    0x5b, 0x3a, 0x55, 0xd8, 0x87, 0x3b
+  };
+  srtp_t srtp_snd, srtp_recv;
+  err_status_t status;
+  int len;
+  srtp_policy_t policy;
+  
+  /*
+   * create a session with a single stream using the default srtp
+   * policy and with the SSRC value 0xcafebabe
+   */
+  crypto_policy_set_aes_cm_256_hmac_sha1_80(&policy.rtp);
+  crypto_policy_set_aes_cm_256_hmac_sha1_80(&policy.rtcp);
+  policy.ssrc.type  = ssrc_specific;
+  policy.ssrc.value = 0xcafebabe;
+  policy.key  = aes_256_test_key;
+  policy.ekt = NULL;
+  policy.window_size = 128;
+  policy.allow_repeat_tx = 0;
+  policy.next = NULL;
+
+  status = srtp_create(&srtp_snd, &policy);
+  if (status)
+    return status;
+ 
+  /* 
+   * protect plaintext, then compare with ciphertext 
+   */
+  len = 28;
+  status = srtp_protect(srtp_snd, srtp_plaintext, &len);
+  if (status || (len != 38))
+    return err_status_fail;
+
+  debug_print(mod_driver, "ciphertext:\n  %s",        
+              octet_string_hex_string(srtp_plaintext, len));
+  debug_print(mod_driver, "ciphertext reference:\n  %s",              
+              octet_string_hex_string(srtp_ciphertext, len));
+
+  if (octet_string_is_eq(srtp_plaintext, srtp_ciphertext, len))
+    return err_status_fail;
+  
+  /*
+   * create a receiver session context comparable to the one created
+   * above - we need to do this so that the replay checking doesn't
+   * complain
+   */
+  status = srtp_create(&srtp_recv, &policy);
+  if (status)
+    return status;
+
+  /*
+   * unprotect ciphertext, then compare with plaintext 
+   */
+  status = srtp_unprotect(srtp_recv, srtp_ciphertext, &len);
+  if (status || (len != 28))
+    return status;
+  
+  if (octet_string_is_eq(srtp_ciphertext, srtp_plaintext_ref, len))
+    return err_status_fail;
+
+  status = srtp_dealloc(srtp_snd);
+  if (status)
+    return status;
+
+  status = srtp_dealloc(srtp_recv);
+  if (status)
+    return status;
+
+  return err_status_ok;
+}
+
+
+err_status_t
+srtp_create_big_policy(srtp_policy_t **list) {
+  extern const srtp_policy_t *policy_array[];
+  srtp_policy_t *p, *tmp;
+  int i = 0;
+  uint32_t ssrc = 0;
+
+  /* sanity checking */
+  if ((list == NULL) || (policy_array[0] == NULL))
+    return err_status_bad_param;
+
+  /* 
+   * loop over policy list, mallocing a new list and copying values
+   * into it (and incrementing the SSRC value as we go along)
+   */
+  tmp = NULL;
+  while (policy_array[i] != NULL) {
+    p  = (srtp_policy_t*) malloc(sizeof(srtp_policy_t));
+    if (p == NULL)
+      return err_status_bad_param;
+    memcpy(p, policy_array[i], sizeof(srtp_policy_t));
+    p->ssrc.type = ssrc_specific;
+    p->ssrc.value = ssrc++;
+    p->next = tmp;
+    tmp = p;
+    i++;
+  }
+  *list = p;
+ 
+  return err_status_ok;
+}
+
+err_status_t
+srtp_dealloc_big_policy(srtp_policy_t *list) {
+  srtp_policy_t *p, *next;
+
+  for (p = list; p != NULL; p = next) {
+    next = p->next;
+    free(p);
+  }
+
+  return err_status_ok;
+}
+
+
+err_status_t
+srtp_test_remove_stream() { 
+  err_status_t status;
+  srtp_policy_t *policy_list, policy;
+  srtp_t session;
+  srtp_stream_t stream;
+  /* 
+   * srtp_get_stream() is a libSRTP internal function that we declare
+   * here so that we can use it to verify the correct operation of the
+   * library
+   */ 
+  extern srtp_stream_t srtp_get_stream(srtp_t srtp, uint32_t ssrc);
+  
+
+  status = srtp_create_big_policy(&policy_list);
+  if (status)
+    return status;
+
+  status = srtp_create(&session, policy_list);
+  if (status)
+    return status;
+
+  /*
+   * check for false positives by trying to remove a stream that's not
+   * in the session
+   */
+  status = srtp_remove_stream(session, htonl(0xaaaaaaaa));
+  if (status != err_status_no_ctx)
+    return err_status_fail;
+  
+  /* 
+   * check for false negatives by removing stream 0x1, then
+   * searching for streams 0x0 and 0x2
+   */
+  status = srtp_remove_stream(session, htonl(0x1));
+  if (status != err_status_ok)
+    return err_status_fail;
+  stream = srtp_get_stream(session, htonl(0x0));
+  if (stream == NULL)
+    return err_status_fail;
+  stream = srtp_get_stream(session, htonl(0x2));
+  if (stream == NULL)
+    return err_status_fail;  
+
+  status = srtp_dealloc(session);
+  if (status != err_status_ok)
+    return status;
+
+  status = srtp_dealloc_big_policy(policy_list);
+  if (status != err_status_ok)
+    return status;
+
+  /* Now test adding and removing a single stream */
+  crypto_policy_set_rtp_default(&policy.rtp);
+  crypto_policy_set_rtcp_default(&policy.rtcp);
+  policy.ssrc.type  = ssrc_specific;
+  policy.ssrc.value = 0xcafebabe;
+  policy.key  = test_key;
+  policy.ekt = NULL;
+  policy.window_size = 128;
+  policy.allow_repeat_tx = 0;
+  policy.next = NULL;
+
+  status = srtp_create(&session, NULL);
+  if (status != err_status_ok)
+    return status;
+  
+  status = srtp_add_stream(session, &policy);
+  if (status != err_status_ok)
+    return status;
+
+  status = srtp_remove_stream(session, htonl(0xcafebabe));
+  if (status != err_status_ok)
+    return status;
+
+  status = srtp_dealloc(session);
+  if (status != err_status_ok)
+    return status;
+
+  return err_status_ok;  
+}
+
+/*
+ * srtp policy definitions - these definitions are used above
+ */
+
+unsigned char test_key[30] = {
+    0xe1, 0xf9, 0x7a, 0x0d, 0x3e, 0x01, 0x8b, 0xe0,
+    0xd6, 0x4f, 0xa3, 0x2c, 0x06, 0xde, 0x41, 0x39,
+    0x0e, 0xc6, 0x75, 0xad, 0x49, 0x8a, 0xfe, 0xeb,
+    0xb6, 0x96, 0x0b, 0x3a, 0xab, 0xe6
+};
+
+
+const srtp_policy_t default_policy = {
+  { ssrc_any_outbound, 0 },  /* SSRC                           */
+  {                      /* SRTP policy                    */                  
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    16,                     /* auth key length in octets   */
+    10,                     /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  {                      /* SRTCP policy                   */
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    16,                     /* auth key length in octets   */
+    10,                     /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  test_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+const srtp_policy_t aes_tmmh_policy = {
+  { ssrc_any_outbound, 0 },     /* SSRC                        */
+  { 
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    UST_TMMHv2,             /* authentication func type    */
+    94,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  { 
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    UST_TMMHv2,             /* authentication func type    */
+    94,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  test_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+const srtp_policy_t tmmh_only_policy = {
+  { ssrc_any_outbound, 0 },     /* SSRC                        */
+  {
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    UST_TMMHv2,             /* authentication func type    */
+    94,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_auth           /* security services flag      */
+  },
+  {
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    UST_TMMHv2,             /* authentication func type    */
+    94,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_auth           /* security services flag      */
+  },
+  test_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+const srtp_policy_t aes_only_policy = {
+  { ssrc_any_outbound, 0 },     /* SSRC                        */ 
+  {
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    NULL_AUTH,              /* authentication func type    */
+    0,                      /* auth key length in octets   */
+    0,                      /* auth tag length in octets   */
+    sec_serv_conf           /* security services flag      */
+  },
+  {
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    NULL_AUTH,              /* authentication func type    */
+    0,                      /* auth key length in octets   */
+    0,                      /* auth tag length in octets   */
+    sec_serv_conf           /* security services flag      */
+  },
+  test_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+const srtp_policy_t hmac_only_policy = {
+  { ssrc_any_outbound, 0 },     /* SSRC                        */
+  {
+    NULL_CIPHER,            /* cipher type                 */
+    0,                      /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    20,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_auth           /* security services flag      */
+  },  
+  {
+    NULL_CIPHER,            /* cipher type                 */
+    0,                      /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    20,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_auth           /* security services flag      */
+  },
+  test_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+const srtp_policy_t null_policy = {
+  { ssrc_any_outbound, 0 },     /* SSRC                        */ 
+  {
+    NULL_CIPHER,            /* cipher type                 */
+    0,                      /* cipher key length in octets */
+    NULL_AUTH,              /* authentication func type    */
+    0,                      /* auth key length in octets   */
+    0,                      /* auth tag length in octets   */
+    sec_serv_none           /* security services flag      */  
+  },
+  {
+    NULL_CIPHER,            /* cipher type                 */
+    0,                      /* cipher key length in octets */
+    NULL_AUTH,              /* authentication func type    */
+    0,                      /* auth key length in octets   */
+    0,                      /* auth tag length in octets   */
+    sec_serv_none           /* security services flag      */  
+  },
+  test_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+unsigned char test_256_key[46] = {
+        0xf0, 0xf0, 0x49, 0x14, 0xb5, 0x13, 0xf2, 0x76,
+        0x3a, 0x1b, 0x1f, 0xa1, 0x30, 0xf1, 0x0e, 0x29,
+        0x98, 0xf6, 0xf6, 0xe4, 0x3e, 0x43, 0x09, 0xd1,
+        0xe6, 0x22, 0xa0, 0xe3, 0x32, 0xb9, 0xf1, 0xb6,
+
+        0x3b, 0x04, 0x80, 0x3d, 0xe5, 0x1e, 0xe7, 0xc9,
+        0x64, 0x23, 0xab, 0x5b, 0x78, 0xd2
+};
+
+const srtp_policy_t aes_256_hmac_policy = {
+  { ssrc_any_outbound, 0 },  /* SSRC                           */
+  {                      /* SRTP policy                    */                  
+    AES_ICM,                /* cipher type                 */
+    46,                     /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    20,                     /* auth key length in octets   */
+    10,                     /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  {                      /* SRTCP policy                   */
+    AES_ICM,                /* cipher type                 */
+    46,                     /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    20,                     /* auth key length in octets   */
+    10,                     /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  test_256_key,
+  NULL,        /* indicates that EKT is not in use */
+  128,         /* replay window size */
+  0,           /* retransmission not allowed */
+  NULL
+};
+
+uint8_t ekt_test_key[16] = {
+  0x77, 0x26, 0x9d, 0xac, 0x16, 0xa3, 0x28, 0xca, 
+  0x8e, 0xc9, 0x68, 0x4b, 0xcc, 0xc4, 0xd2, 0x1b
+};
+
+#include "ekt.h"
+
+ekt_policy_ctx_t ekt_test_policy = {
+  0xa5a5,                   /* SPI */
+  EKT_CIPHER_AES_128_ECB,
+  ekt_test_key,
+  NULL
+};
+
+const srtp_policy_t hmac_only_with_ekt_policy = {
+  { ssrc_any_outbound, 0 },     /* SSRC                        */
+  {
+    NULL_CIPHER,            /* cipher type                 */
+    0,                      /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    20,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_auth           /* security services flag      */
+  },  
+  {
+    NULL_CIPHER,            /* cipher type                 */
+    0,                      /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    20,                     /* auth key length in octets   */
+    4,                      /* auth tag length in octets   */
+    sec_serv_auth           /* security services flag      */
+  },
+  test_key,
+  &ekt_test_policy,        /* indicates that EKT is not in use */
+  128,                     /* replay window size */
+  0,                       /* retransmission not allowed */
+  NULL
+};
+
+
+/*
+ * an array of pointers to the policies listed above
+ *
+ * This array is used to test various aspects of libSRTP for
+ * different cryptographic policies.  The order of the elements
+ * matters - the timing test generates output that can be used
+ * in a plot (see the gnuplot script file 'timing').  If you 
+ * add to this list, you should do it at the end.
+ */
+
+#define USE_TMMH 0
+
+const srtp_policy_t *
+policy_array[] = {
+  &hmac_only_policy,
+#if USE_TMMH
+  &tmmh_only_policy,
+#endif
+  &aes_only_policy,
+#if USE_TMMH
+  &aes_tmmh_policy,
+#endif
+  &default_policy,
+  &null_policy,
+  &aes_256_hmac_policy,
+  &hmac_only_with_ekt_policy,
+  NULL
+};
+
+const srtp_policy_t wildcard_policy = {
+  { ssrc_any_outbound, 0 }, /* SSRC                        */
+  {                      /* SRTP policy                    */                  
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    16,                     /* auth key length in octets   */
+    10,                     /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  {                      /* SRTCP policy                   */
+    AES_128_ICM,            /* cipher type                 */
+    30,                     /* cipher key length in octets */
+    HMAC_SHA1,              /* authentication func type    */
+    16,                     /* auth key length in octets   */
+    10,                     /* auth tag length in octets   */
+    sec_serv_conf_and_auth  /* security services flag      */
+  },
+  test_key,
+  NULL,
+  128,                   /* replay window size */
+  0,                     /* retransmission not allowed */
+  NULL
+};