Support for SRTP

[bennylp]

Please see the documentation in SRTP wiki page.

[bennylp]

The bulk of the work was done in separate branch, you can see the detailed changelogs for that branch in ticket #452.

Detailed changelogs on trunk is below.

r1729:

• added <stdint.h> header detection in autoconf, and store the result in PJ_HAS_STDINT_H macro in <pj/compat/os_auto.h>

r1730:

• imported libsrtp into third_party directory

r1732:

• Added PJSIP_ESESSIONINSECURE error code in sip_errno.[hc] to require that secure session shall be used

r1733:

• related to this ticket: added new invite session API pjsip_inv_verify_request2() which takes additional remote SDP, to avoid parsing SDP multiple times

r1735: (the bulk of SRTP changes, back-ported from SRTP branch)

• new files in PJMEDIA: transport_srtp.[hc]
• new configuration macro: PJMEDIA_HAS_SRTP (default=1)
• modified project dependencies to include libsrtp
• modified Samples-vc.mak, add libsrtp as third party library
• modified transport interface:
  • modified transport_udp and transport_ice to follow the new interface
  • modified pjsua_media.c to use the new media transport interface
• added new PJMEDIA error codes specific to SRTP, and map libsrtp error into PJMEDIA error code
• modified PJSUA-LIB API:
  • added use_srtp and srtp_secure_signaling settings in both pjsua_config and pjsua_acc_config
• added new --use-srtp option in pjsua

[bennylp]

In r1736:

• added eVC target for SRTP and libsrtp

[bennylp]

In r1737:

• fixed crashed on SRTP error string lookup

[bennylp]

In r1738:

• SRTP will TRY to use /dev/urandom if it's usable, otherwise it will fallback to using rand()
• autoconf script is updated to detect <fcntl.h> (needed to open "/dev/urandom")

[bennylp]

In r1739:

• Fixed potential crash when performing SRTP error lookup
• added more information in SRTP transport logging

[bennylp]

r1740:

• error in CPU type detection causing libsrtp initialization error

[bennylp]

r1741:

• Fixed libsrtp random string generation on Win32 (caused by r1738 above!)

r1742:

• Return 406/Not Acceptable if SRTP negotiation failed instead of 500

[bennylp]

r1745:

• fix bug in secure signaling determination in pjsua_call.c, and added --srtp-secure option in pjsua to control signaling security requirement for SRTP"

[bennylp]

r1746:

• disable CPU_RISC as it seems to be broken (tested on ARM)

[bennylp]

r1758:

• --srtp-use option in pjsua did not change account setting

[bennylp]

r1759:

• fixed bug: unable to accept RTP/AVP offer with a=crypto attribute when use_sdp is set to zero

[nanang]

Attachment transport_srtp.patch:

• added check for opt==NULL
• added bad keys sample
• changed flow for answerer receiving AVP with crypto attr

Attachment streamutil.patch:

• moved block 'include' up, so usage/desc string recognize macro PJMEDIA_HAS_SRTP

[bennylp]

r1760:

• undo r1759 and replace it with other patches to fix unable to accept RTP/AVP offer with a=crypto attribute when use_sdp is set to zero. Also minor fix to streamutil

[bennylp]

In r1763:

• removed const from media transport's RTP and RTCP callback to allow packet to be modified in place.

[bennylp]

In r1764:

• mismatch in libsrtp output library name causing error when building samples in VC6

[bennylp]

In r1774:

• fixed signaling security level calculation in pjsua_call.c

[bennylp]

r1780:

• Removed const on on_rx_rtp() and on_rx_rtcp() functions arguments in stream.c and srtp.c

[bennylp]

r1784:

• disable SRTP support on Symbian

[bennylp]

r1803:

• crash on Win32 App because stderr is NULL. Thanks Truong Thanh Quang.

[bennylp]

r1807:

• Related to r1803 above removed fprintf()/printf() altogether and replaced it with err_report() call

[bennylp]

In r1883:

• Bug in pjsua-lib: if call is held and resumed, SRTP transport will use itself as the underlying transport.

[bennylp]

In r1884:

• Bug in previous patch which was applied to r1884. It has been rolled-back.
• This revision is the real fix for that bug in pjsua-lib: if call is held and resumed, SRTP transport will use itself as the underlying transport.

[bennylp]

Ticket reopened for porting SRTP to Symbian.

[nanang]

In r1979: enabled SRTP on Symbian, initial source.