diff -r ebc84c812384 -r 46218c8b8afa Symbian3/PDK/Source/GUID-922F292E-9420-593B-B226-2764C5F29DF9.dita --- a/Symbian3/PDK/Source/GUID-922F292E-9420-593B-B226-2764C5F29DF9.dita Thu Mar 11 15:24:26 2010 +0000 +++ b/Symbian3/PDK/Source/GUID-922F292E-9420-593B-B226-2764C5F29DF9.dita Thu Mar 11 18:02:22 2010 +0000 @@ -1,83 +1,83 @@ - - - - - -Encrypting -RTP Packet Data

SRTP generates SRTP packets from the RTP stream and forwards -the packets to the receiver. SRTP transforms incoming SRTP packets to RTP -packets and passes them up the stack. To ensure the confidentiality of the -packet content, data encryption is used.

The data packet consists -of payload and header. The payload is encrypted. An authentication is performed -collectively on the header and the encrypted payload.

Encrypted RTP -packet data is encapsulated for transmission in a single lower-layer packet -as a unit. The encrypted SRTP packet consists of the encrypted RTP payload -and RTP header. The encrypted packet may be the exact size of the plain packet -or larger.

The presence of encryption and the correct usage of key -are confirmed by the receiver through header and payload validity checks. -

An SRTP session must be created and initialized before an application -requests for a RTP payload encryption.

- -An application requests -for encryption of RTP packet. - -The SRTP DLL checks -for the cryptographic context of the input stream. If a match is not found, -SRTP DLL checks for the cryptographic context of the session. - - -The packet is encrypted using ProtectRTPL() API -of the class CSRTPSession.The session -keys in the cryptographic context of the current SRTP session are used for -encryption. - - -The prototype for the API ProtectRTPL() is -as described below. - - IMPORT_C HBufC8* ProtectRTPL(TUint aSSRC, const TDesC8& aPacket); - - -This API is invoked if the session finds a match stream and protect -stream. -aSSRC is the input parameter that contains the Synchronisation Source -(SSRC). Synchronisation Source is the source for stream of RTP packets identified -by a 32 bit numeric. SSRC identifier is a part of the RTP packet header. -aPacket is the input parameter that contains the packet to be protected(encrypted). -The packet includes RTP header and the paleout. The length of descriptor should -match the actual data length. A mismatch in the length descriptor and actual -length may lead to incorrect encryption. -HBufC8 is the output parameter that contains the encrypted packet. -The API leaves, if a matching stream is not found. - - - -The SRTP DLL updates -the count of packets encrypted. - - -

On successful execution of the API, encrypted data is returned.

- -Creating -an SRTP Session -Creating -a Cryptographic Context -Creating -an SRTP Stream -Encrypting - RTCP Packet Data -Decrypting -RTP Packet Data -Decrypting - RTCP Packet Data -Updating -Master Key -Managing - Master Key + + + + + +Encrypting +RTP Packet Data

SRTP generates SRTP packets from the RTP stream and forwards +the packets to the receiver. SRTP transforms incoming SRTP packets to RTP +packets and passes them up the stack. To ensure the confidentiality of the +packet content, data encryption is used.

The data packet consists +of payload and header. The payload is encrypted. An authentication is performed +collectively on the header and the encrypted payload.

Encrypted RTP +packet data is encapsulated for transmission in a single lower-layer packet +as a unit. The encrypted SRTP packet consists of the encrypted RTP payload +and RTP header. The encrypted packet may be the exact size of the plain packet +or larger.

The presence of encryption and the correct usage of key +are confirmed by the receiver through header and payload validity checks. +

An SRTP session must be created and initialized before an application +requests for a RTP payload encryption.

+ +An application requests +for encryption of RTP packet. + +The SRTP DLL checks +for the cryptographic context of the input stream. If a match is not found, +SRTP DLL checks for the cryptographic context of the session. + + +The packet is encrypted using ProtectRTPL() API +of the class CSRTPSession.The session +keys in the cryptographic context of the current SRTP session are used for +encryption. + + +The prototype for the API ProtectRTPL() is +as described below. + + IMPORT_C HBufC8* ProtectRTPL(TUint aSSRC, const TDesC8& aPacket); + + +This API is invoked if the session finds a match stream and protect +stream. +aSSRC is the input parameter that contains the Synchronisation Source +(SSRC). Synchronisation Source is the source for stream of RTP packets identified +by a 32 bit numeric. SSRC identifier is a part of the RTP packet header. +aPacket is the input parameter that contains the packet to be protected(encrypted). +The packet includes RTP header and the paleout. The length of descriptor should +match the actual data length. A mismatch in the length descriptor and actual +length may lead to incorrect encryption. +HBufC8 is the output parameter that contains the encrypted packet. +The API leaves, if a matching stream is not found. + + + +The SRTP DLL updates +the count of packets encrypted. + + +

On successful execution of the API, encrypted data is returned.

+ +Creating +an SRTP Session +Creating +a Cryptographic Context +Creating +an SRTP Stream +Encrypting + RTCP Packet Data +Decrypting +RTP Packet Data +Decrypting + RTCP Packet Data +Updating +Master Key +Managing + Master Key \ No newline at end of file