The Tor Browser: netwerk/srtp/src/include/srtp_priv.h@b8a032363ba2 (annotated)

netwerk/srtp/src/include/srtp_priv.h@b8a032363ba2 (annotated)

netwerk/srtp/src/include/srtp_priv.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * srtp_priv.h
  *
  * private internal data structures and functions 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.
  *
  */
 #ifndef SRTP_PRIV_H
 #define SRTP_PRIV_H
 #include "srtp.h"
 #include "rdbx.h"
 #include "rdb.h"
 #include "integers.h"
 /*
  * an srtp_hdr_t represents the srtp header
  *
  * in this implementation, an srtp_hdr_t is assumed to be 32-bit aligned
  *
  * (note that this definition follows that of RFC 1889 Appendix A, but
  * is not identical)
  */
 #ifndef WORDS_BIGENDIAN
 /*
  * srtp_hdr_t represents an RTP or SRTP header.  The bit-fields in
  * this structure should be declared "unsigned int" instead of
  * "unsigned char", but doing so causes the MS compiler to not
  * fully pack the bit fields.
  */
 typedef struct {
   unsigned char cc:4;	/* CSRC count             */
   unsigned char x:1;	/* header extension flag  */
   unsigned char p:1;	/* padding flag           */
   unsigned char version:2; /* protocol version    */
   unsigned char pt:7;	/* payload type           */
   unsigned char m:1;	/* marker bit             */
   uint16_t seq;		/* sequence number        */
   uint32_t ts;		/* timestamp              */
   uint32_t ssrc;	/* synchronization source */
 } srtp_hdr_t;
 #else /*  BIG_ENDIAN */
 typedef struct {
   unsigned char version:2; /* protocol version    */
   unsigned char p:1;	/* padding flag           */
   unsigned char x:1;	/* header extension flag  */
   unsigned char cc:4;	/* CSRC count             */
   unsigned char m:1;	/* marker bit             */
   unsigned pt:7;	/* payload type           */
   uint16_t seq;		/* sequence number        */
   uint32_t ts;		/* timestamp              */
   uint32_t ssrc;	/* synchronization source */
 } srtp_hdr_t;
 #endif
 typedef struct {
   uint16_t profile_specific;    /* profile-specific info               */
   uint16_t length;              /* number of 32-bit words in extension */
 } srtp_hdr_xtnd_t;
 /*
  * srtcp_hdr_t represents a secure rtcp header
  *
  * in this implementation, an srtcp header is assumed to be 32-bit
  * alinged
  */
 #ifndef WORDS_BIGENDIAN
 typedef struct {
   unsigned char rc:5;		/* reception report count */
   unsigned char p:1;		/* padding flag           */
   unsigned char version:2;	/* protocol version       */
   unsigned char pt:8;		/* payload type           */
   uint16_t len;			/* length                 */
   uint32_t ssrc;	       	/* synchronization source */
 } srtcp_hdr_t;
 typedef struct {
   unsigned int index:31;    /* srtcp packet index in network order! */
   unsigned int e:1;         /* encrypted? 1=yes */
   /* optional mikey/etc go here */
   /* and then the variable-length auth tag */
 } srtcp_trailer_t;
 #else /*  BIG_ENDIAN */
 typedef struct {
   unsigned char version:2;	/* protocol version       */
   unsigned char p:1;		/* padding flag           */
   unsigned char rc:5;		/* reception report count */
   unsigned char pt:8;		/* payload type           */
   uint16_t len;			/* length                 */
   uint32_t ssrc;	       	/* synchronization source */
 } srtcp_hdr_t;
 typedef struct {
   unsigned int version:2;  /* protocol version                     */
   unsigned int p:1;        /* padding flag                         */
   unsigned int count:5;    /* varies by packet type                */
   unsigned int pt:8;       /* payload type                         */
   uint16_t length;         /* len of uint32s of packet less header */
 } rtcp_common_t;
 typedef struct {
   unsigned int e:1;         /* encrypted? 1=yes */
   unsigned int index:31;    /* srtcp packet index */
   /* optional mikey/etc go here */
   /* and then the variable-length auth tag */
 } srtcp_trailer_t;
 #endif
 /*
  * the following declarations are libSRTP internal functions
  */
 /*
  * srtp_get_stream(ssrc) returns a pointer to the stream corresponding
  * to ssrc, or NULL if no stream exists for that ssrc
  */
 srtp_stream_t
 srtp_get_stream(srtp_t srtp, uint32_t ssrc);
 /*
  * srtp_stream_init_keys(s, k) (re)initializes the srtp_stream_t s by
  * deriving all of the needed keys using the KDF and the key k.
  */
 err_status_t
 srtp_stream_init_keys(srtp_stream_t srtp, const void *key);
 /*
  * srtp_stream_init(s, p) initializes the srtp_stream_t s to
  * use the policy at the location p
  */
 err_status_t
 srtp_stream_init(srtp_stream_t srtp,
 		 const srtp_policy_t *p);
 /*
  * libsrtp internal datatypes
  */
 typedef enum direction_t {
   dir_unknown       = 0,
   dir_srtp_sender   = 1,
   dir_srtp_receiver = 2
 } direction_t;
 /*
  * an srtp_stream_t has its own SSRC, encryption key, authentication
  * key, sequence number, and replay database
  *
  * note that the keys might not actually be unique, in which case the
  * cipher_t and auth_t pointers will point to the same structures
  */
 typedef struct srtp_stream_ctx_t {
   uint32_t   ssrc;
   cipher_t  *rtp_cipher;
   auth_t    *rtp_auth;
   rdbx_t     rtp_rdbx;
   sec_serv_t rtp_services;
   cipher_t  *rtcp_cipher;
   auth_t    *rtcp_auth;
   rdb_t      rtcp_rdb;
   sec_serv_t rtcp_services;
   key_limit_ctx_t *limit;
   direction_t direction;
   int        allow_repeat_tx;
   ekt_stream_t ekt;
   struct srtp_stream_ctx_t *next;   /* linked list of streams */
 } srtp_stream_ctx_t;
 /*
  * an srtp_ctx_t holds a stream list and a service description
  */
 typedef struct srtp_ctx_t {
   srtp_stream_ctx_t *stream_list;     /* linked list of streams            */
   srtp_stream_ctx_t *stream_template; /* act as template for other streams */
 } srtp_ctx_t;
 /*
  * srtp_handle_event(srtp, srtm, evnt) calls the event handling
  * function, if there is one.
  *
  * This macro is not included in the documentation as it is
  * an internal-only function.
  */
 #define srtp_handle_event(srtp, strm, evnt)         \
    if(srtp_event_handler) {                         \
       srtp_event_data_t data;                       \
       data.session = srtp;                          \
       data.stream  = strm;                          \
       data.event   = evnt;                          \
       srtp_event_handler(&data);                    \
 }
 #endif /* SRTP_PRIV_H */

The Tor Browser / annotate

netwerk/srtp/src/include/srtp_priv.h@b8a032363ba2 (annotated)

netwerk/srtp/src/include/srtp_priv.h