Update libsrtp to version 2.0

srtp/README

-Secure RTP (SRTP) Reference Implementation
-David A. McGrew
-Cisco Systems, Inc.
-mcgrew@cisco.com
-
-
-This package provides an implementation of the Secure Real-time
-Transport Protocol (SRTP), the Universal Security Transform (UST), and
-a supporting cryptographic kernel.  These mechanisms are documented in
-the Internet Drafts in the doc/ subdirectory.  The SRTP API is
-documented in include/srtp.h, and the library is in libsrtp.a (after
-compilation).  An overview and reference manual is available in
-doc/libsrtp.pdf.  The PDF documentation is more up to date than this
-file.
-
-
-Installation:
-
-./configure [ options ]       # GNU autoconf script 
-make                          # or gmake if needed; use GNU make
-
-The configure script accepts the following options:
-
-   --help              provides a usage summary
-   --disable-debug     compile without the runtime debugging system
-   --enable-syslog     use syslog for error reporting
-   --disable-stdout    use stdout for error reporting
-   --enable-console    use /dev/console for error reporting
-   --enable-openssl    use OpenSSL crypto primitives
-   --gdoi              use GDOI key management (disabled at present)
-
-By default, debugging is enabled and stdout is used for debugging.
-You can use the above configure options to have the debugging output
-sent to syslog or the system console.  Alternatively, you can define
-ERR_REPORTING_FILE in include/conf.h to be any other file that can be
-opened by libSRTP, and debug messages will be sent to it.  
-
-This package has been tested on Mac OS X (powerpc-apple-darwin1.4),
-Cygwin (i686-pc-cygwin), and Sparc (sparc-sun-solaris2.6).  Previous
-versions have been tested on Linux and OpenBSD on both x86 and sparc
-platforms.
-
-A quick tour of this package:
-
-Makefile                targets: all, clean, ...
-README                  this file
-CHANGES                 change log 
-VERSION                 version number of this package
-LICENSE                 legal details (it's a BSD-like license)
-crypto/ciphers/         ciphers (null, aes_icm, ...)
-crypto/math/            crypto math routines
-crypto/hash/            crypto hashing (hmac, tmmhv2, ...)
-crypto/replay/          replay protection
-doc/                    documentation: rfcs, apis, and suchlike
-include/                include files for all code in distribution
-srtp/                   secure real-time transport protocol implementation
-tables/                 apps for generating tables (useful in porting)
-test/                   test drivers 
-
-
-Applications
-
-  Several test drivers and a simple and portable srtp application
-  are included in the test/ subdirectory.
-
-  test driver   function tested 
-  -------------------------------------------------------------
-  kernel_driver crypto kernel (ciphers, auth funcs, rng)
-  srtp_driver   srtp in-memory tests (does not use the network)
-  rdbx_driver   rdbx (extended replay database)
-  roc_driver    extended sequence number functions 
-  replay_driver replay database (n.b. not used in libsrtp)
-  cipher_driver ciphers 
-  auth_driver   hash functions 
-
-  The app rtpw is a simple rtp application which reads words from
-  /usr/dict/words and then sends them out one at a time using [s]rtp.
-  Manual srtp keying uses the -k option; automated key management
-  using gdoi will be added later.
-
-usage: rtpw [-d <debug>]* [-k|b <key> [-a][-e <key size>][-g]] [-s | -r] dest_ip dest_port
-or     rtpw -l
-
-  Either the -s (sender) or -r (receiver) option must be chosen.
-
-  The values dest_ip, dest_port are the ip address and udp port to
-  which the dictionary will be sent, respectively.  
-
-  options:
-
-  -s            (s)rtp sender - causes app to send words
-
-  -r            (s)rtp receive - causes app to receive words
-
-  -k <key>      use srtp master key <key>, where the
-                key is a hexadecimal value (without the
-                leading "0x")
-
-  -b <key>      same as -k but with base64 encoded key
-
-  -e <keysize>  encrypt/decrypt (for data confidentiality)
-                (requires use of -k option as well)
-                (use 128, 192, or 256 for keysize)
-
-  -g            use AES-GCM mode (must be used with -e) 
-
-  -a            message authentication 
-                (requires use of -k option as well)
-
-  -l            list debug modules
-
-  -d <debug>    turn on debugging for module <debug>
-  -i            specify input/output file 
-                (instead of using dictionary file)
-
-
-In order to get random 30-byte values for use as key/salt pairs , you
-can use the following bash function to format the output of
-/dev/random (where that device is available).
-
-function randhex() {
-   cat /dev/random | od --read-bytes=32 --width=32 -x | awk '{ print $2 $3 $4 $5 $6 $7 $8 $9 $10 $11 $12 $13 $14 $15 $16 }'
-}
-
-
-An example of an SRTP session using two rtpw programs follows:
-
-set k=c1eec3717da76195bb878578790af71c4ee9f859e197a414a78d5abc7451
-
-[sh1]$ test/rtpw -s -k $k -e 128 -a 0.0.0.0 9999 
-Security services: confidentiality message authentication
-set master key/salt to C1EEC3717DA76195BB878578790AF71C/4EE9F859E197A414A78D5ABC7451
-setting SSRC to 2078917053
-sending word: A
-sending word: a
-sending word: aa
-sending word: aal
-...
-
-[sh2]$ test/rtpw -r -k $k -e 128 -a 0.0.0.0 9999 
-security services: confidentiality message authentication
-set master key/salt to C1EEC3717DA76195BB878578790AF71C/4EE9F859E197A414A78D5ABC7451
-19 octets received from SSRC 2078917053 word: A
-19 octets received from SSRC 2078917053 word: a
-20 octets received from SSRC 2078917053 word: aa
-21 octets received from SSRC 2078917053 word: aal
-...
-
-Implementation Notes
-
-  * The srtp_protect() function assumes that the buffer holding the
-    rtp packet has enough storage allocated that the authentication 
-    tag can be written to the end of that packet.  If this assumption
-    is not valid, memory corruption will ensue.  
-
-  * Automated tests for the crypto functions are provided through
-    the cipher_type_self_test() and auth_type_self_test() functions.
-    These functions should be used to test each port of this code 
-    to a new platform.
-
-  * Replay protection is contained in the crypto engine, and
-    tests for it are provided.
-
-  * This implementation provides calls to initialize, protect, and
-    unprotect RTP packets, and makes as few as possible assumptions
-    about how these functions will be called.  For example, the
-    caller is not expected to provide packets in order (though if
-    they're called more than 65k out of sequence, synchronization
-    will be lost).
-    
-  * The sequence number in the rtp packet is used as the low 16 bits
-    of the sender's local packet index. Note that RTP will start its
-    sequence number in a random place, and the SRTP layer just jumps
-    forward to that number at its first invocation.  An earlier
-    version of this library used initial sequence numbers that are
-    less than 32,768; this trick is no longer required as the
-    rdbx_estimate_index(...) function has been made smarter.
-
-  * The replay window is 128 bits in length, and is hard-coded to this
-    value for now.  
-
-