diff options
Diffstat (limited to 'pjmedia/include/pjmedia/transport_srtp.h')
| -rw-r--r-- | pjmedia/include/pjmedia/transport_srtp.h | 54 |
1 files changed, 49 insertions, 5 deletions
diff --git a/pjmedia/include/pjmedia/transport_srtp.h b/pjmedia/include/pjmedia/transport_srtp.h index f7ea291d..d6ccc2e1 100644 --- a/pjmedia/include/pjmedia/transport_srtp.h +++ b/pjmedia/include/pjmedia/transport_srtp.h @@ -21,12 +21,52 @@ /** * @file srtp.h - * @brief transport SRTP encapsulates secure media transport. + * @brief Secure RTP (SRTP) transport. */ #include <pjmedia/transport.h> +/** + * @defgroup PJMEDIA_TRANSPORT_SRTP Secure RTP (SRTP) Transport Adapter + * @ingroup PJMEDIA_TRANSPORT + * @brief Media transport adapter to add SRTP feature to existing transports + * @{ + * + * This module implements SRTP as described by RFC 3711, using RFC 4568 as + * key exchange method. It implements \ref PJMEDIA_TRANSPORT_H to integrate + * with the rest of PJMEDIA framework. + * + * As we know, media transport is separated from the stream object (which + * does the encoding/decoding of PCM frames, (de)packetization of RTP/RTCP + * packets, and de-jitter buffering). The connection between stream and media + * transport is established when the stream is created (we need to specify + * media transport during stream creation), and the interconnection can be + * depicted from the diagram below: + * + \image html media-transport.PNG + + * I think the diagram above is self-explanatory. + * + * SRTP functionality is implemented as some kind of "adapter", which is + * plugged between the stream and the actual media transport that does + * sending/receiving RTP/RTCP packets. When SRTP is used, the interconnection + * between stream and transport is like the diagram below: + * + \image html media-srtp-transport.PNG + + * So to stream, the SRTP transport behaves as if it is a media transport + * (because it is a media transport), and to the media transport it behaves + * as if it is a stream. The SRTP object then forwards RTP packets back and + * forth between stream and the actual transport, encrypting/decrypting + * the RTP/RTCP packets as necessary. + * + * The neat thing about this design is the SRTP "adapter" then can be used + * to encrypt any kind of media transports. We currently have UDP and ICE + * media transports that can benefit SRTP, and we could add SRTP to any + * media transports that will be added in the future. + */ + PJ_BEGIN_DECL @@ -55,7 +95,7 @@ typedef struct pjmedia_srtp_crypto /** Crypto name. */ pj_str_t name; - /* Flags, bitmask from #pjmedia_srtp_crypto_option */ + /** Flags, bitmask from #pjmedia_srtp_crypto_option */ unsigned flags; } pjmedia_srtp_crypto; @@ -168,7 +208,7 @@ PJ_DECL(pj_status_t) pjmedia_transport_srtp_create( * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_transport_srtp_start( - pjmedia_transport *tp, + pjmedia_transport *srtp, const pjmedia_srtp_crypto *tx, const pjmedia_srtp_crypto *rx); @@ -181,7 +221,7 @@ PJ_DECL(pj_status_t) pjmedia_transport_srtp_start( * * @see #pjmedia_transport_srtp_start() */ -PJ_DECL(pj_status_t) pjmedia_transport_srtp_stop(pjmedia_transport *tp); +PJ_DECL(pj_status_t) pjmedia_transport_srtp_stop(pjmedia_transport *srtp); /** @@ -192,9 +232,13 @@ PJ_DECL(pj_status_t) pjmedia_transport_srtp_stop(pjmedia_transport *tp); * @return member media transport. */ PJ_DECL(pjmedia_transport*) pjmedia_transport_srtp_get_member( - pjmedia_transport *tp); + pjmedia_transport *srtp); PJ_END_DECL +/** + * @} + */ + #endif /* __PJMEDIA_TRANSPORT_SRTP_H__ */ |