CmpTlsAccept (FUN) ¶ FUNCTION CmpTlsAccept : RTS_IEC_RESULT Starts handshaking on the server side. The client has to initiate the handshaking. This is the first function call on the serverside after establishing the unterlaying connection. Data has to be received first. This function will is likley to read and write data. InOut: Scope Name Type Comment Return CmpTlsAccept RTS_IEC_RESULT Result of this operation. May be one of these values: ERR_OK: No error. Everything worked as expected. ERR_NOTINITIALIZED: The TLS component was not initialized proberly. ERR_TLS_CONNECTION_CLOSED: The TLS connection is closed. Use TlsShutdown to shutdown locally. ERR_TLS_WANT_READ: The operation needs TO read data FROM the IO system. There is no data available. ERR_TLS_WANT_WRITE: The operation needs to write data to the IO system. This is not possible. ERR_TLS_RETRY_OPERATION: Something went wrong. Try the same function call again ERR_TLS_IO_SYSTEM: An error in the unterlaying IO system. ERR_TLS_INTERNAL: An internal Error of the TLS Component ERR_FAILED: Unknown error. Input hTlsConn RTS_IEC_HANDLE Handle of the TLS connection, created with one of the TLSxxxOpen functions

CmpTlsBufferDataReceived (FUN) ¶ FUNCTION CmpTlsBufferDataReceived : RTS_IEC_RESULT This function is used to indicate that the Rx buffer contains new TLS data. Call this function is new data have arrived. All data of the buffer has to be consumed by the TLS implementation before overwritting the existing data and calling this funciton. Call TlsRead until the corresponding error code is returned. If not all data is consumed the TLS stream will be broken and the data can’t be decrypted anymore. The Rx buffer will not be changed. InOut: Scope Name Type Comment Return CmpTlsBufferDataReceived RTS_IEC_RESULT Input hTlsConn RTS_IEC_HANDLE Handle to the TLS connection. Must have been created with CmpTlsBufferOpen

CmpTlsBufferDataSent (FUN) ¶ FUNCTION CmpTlsBufferDataSent : RTS_IEC_RESULT This function is used to indicate that the data written by the TLS implementation has been sent to the peer. If this function is called the TLS implementation will start writing it’s output at the beginning of the Tx buffer again. Call this function if the data of the Tx buffer has been sent. The length parameter of the Tx buffer will be set to 0. InOut: Scope Name Type Comment Return CmpTlsBufferDataSent RTS_IEC_RESULT Input hTlsConn RTS_IEC_HANDLE Handle to the TLS connection. Must have been created with CmpTlsBufferOpen

CmpTlsBufferDataToSendAvailable (FUN) ¶ FUNCTION CmpTlsBufferDataToSendAvailable : BOOL This function is called to determine if the tx buffer contains data which should be sent to the peer. InOut: Scope Name Type Comment Return CmpTlsBufferDataToSendAvailable BOOL Input hTlsConn RTS_IEC_HANDLE Handle to the TLS connection. Must have been created with CmpTlsBufferOpen

CmpTlsBufferOpen (FUN) ¶ FUNCTION CmpTlsBufferOpen : RTS_IEC_HANDLE Create a TLS connection around any existing transport media. There are two buffers needed: a send and a receive buffer. Put the data received from the peer to the Rx buffer. The data written by the TLS implementation will be put to the Tx buffer. This buffer has to be sent to the peer after calling the connect, accept or write functions. Maybe after calling the read function the buffer has to be sent too. This depends on internal TLS protocol stuff (change of session keys etc) which may occur at any time. This will be indicated throuth the corresponding returned flag. The TLS connection will be established explicit by calling TSLConnect, or on the server side by calling the Accept function. If the handshaking hasn’t finished the read and write functions will internally finish the handshaking until the connection is established. The implementation will start writing at the beginning at each call. If the function indicated that the the data must be sent the next call will overwrite the data in the Tx buffer. So the caller must handle the data before calling the next TLS function. The buffers given here contain raw TLS protocol data. This data has to be transferred to the peer using a reliable way. The packages have to arrive completely and in the right order. Otherwise TLS won’t work. To read or to write the corresponding plaintext data use the TlsRead and TlsWrite functions. Handling is done as follows: Received data: The bytestrings pointer will point to the beginning of the data. The bytestrings max length will hold the buffers size The bytestrings length will hold the current available amount of data. The function ResetRx will not change any of the byte string. Only the internal read position will be set to the beginning of the buffer Transmit data: The bytestrings pointer will point to the of the empty writing buffer. The bytestrings max length will hold the buffer size The bytestrings length will contain the amount of data written by the TLS implementation. The function ResetTx will reset the internal write position. The length of the bytestring will be set to 0. InOut: Scope Name Type Comment Return CmpTlsBufferOpen RTS_IEC_HANDLE The handle to the created TLS connection, or RTS_INVALID_HANDLE, if operation failed. Input hTlsContext RTS_IEC_HANDLE Handle to the TLS configuration context. Create by CmpTlsCreateContext pRxBuffer POINTER TO RtsByteString Pointer to the buffer containing the data received from the peer. pTxBuffer POINTER TO RtsByteString Pointer to the buffer containing the data to be sent to the peer. pResult POINTER TO RTS_IEC_RESULT Result of this operation. Possible values: ERR_OK: The TLS connection was created successful. ERR_NOMEMORY: The TLS connection could not be created. No memory available ERR_INVALID_HANDLE: The TLS connection could not be created. The given context handle is invalid. ERR_PARAMETER: Some parameters where inconsistent or wrong.

CmpTlsClose (FUN) ¶ FUNCTION CmpTlsClose : RTS_IEC_RESULT lose the TLS connection. All data will be cleand up. The handle used for creating the connection will be closed too. No shutdown is done here. This is allowed by the TLS protocol. InOut: Scope Name Type Comment Return CmpTlsClose RTS_IEC_RESULT Result of this operation. May be one of these values: ERR_OK: No error. Everything worked as expected. ERR_FAILED: Unknown error. Input hTlsConn RTS_IEC_HANDLE Handle of the TLS connection, created with one of the TLSxxxOpen functions

CmpTlsConnect (FUN) ¶ FUNCTION CmpTlsConnect : RTS_IEC_RESULT Starts handshaking on the client side. This data is likley to read and write data. InOut: Scope Name Type Comment Return CmpTlsConnect RTS_IEC_RESULT Result of this operation. May be one of these values: ERR_OK: No error. Everything worked as expected. ERR_NOTINITIALIZED: The TLS component was not initialized proberly. ERR_TLS_CONNECTION_CLOSED: The TLS connection is closed. Use TlsShutdown to shutdown locally. ERR_TLS_WANT_READ: The operation needs TO read data FROM the IO system. There is no data available. ERR_TLS_WANT_WRITE: The operation needs to write data to the IO system. This is not possible. ERR_TLS_RETRY_OPERATION: Something went wrong. Try the same function call again ERR_TLS_IO_SYSTEM: An error in the unterlaying IO system. ERR_TLS_INTERNAL: An internal Error of the TLS Component ERR_FAILED: Unknown error. Input hTlsConn RTS_IEC_HANDLE Handle of the TLS connection, created with one of the TLSNewConn functions

CmpTlsCreateContext (FUN) ¶ FUNCTION CmpTlsCreateContext : RTS_IEC_HANDLE This function create a TLS context. This context is needed to perform TLS communication using the SysSocket2 library. The context contains all informaiton how to handle this TLS connection. InOut: Scope Name Type Initial Comment Return CmpTlsCreateContext RTS_IEC_HANDLE Handle to the new accepted socket or RTS_INVALID_HANDLE if failed. Input hCert RTS_IEC_HANDLE RTS_INVALID_HANDLE Handle to a certificate. The private key of this certificate has to be available. Can be RTS_INVALID_HANDLE for client connections. If the server requires a client certificate the connection will fail in these case. tlsMethod CmpTls_Interfaces.CmpTlsMethod Protocol version and role in the communication. TLS1.2 is suggested for new implementations. Default will be TLS1.2 client. cipherList POINTER TO STRING 0 Allowed chipers used by this connection. Leave 0 to get default. Default will result in ciphers with HIGH encryption strength and Diffie Hellman key exchange. verifyMode DWORD Set up how to verify the peer. The settings differ between client and server. See CmpTlsVerifyMode for details. Default results in: Client -> Verify the peer. Server -> Do not Verify Peer The options of CmpTlsConstans can be combined by adding them. pResult POINTER TO RTS_IEC_RESULT Operations Result

CmpTlsCreateContext2 (FUN) ¶ FUNCTION CmpTlsCreateContext2 : RTS_IEC_HANDLE This function create a TLS context. This context is needed to perform TLS communication using the SysSocket2 library. The context contains all informaiton how to handle this TLS connection. InOut: Scope Name Type Initial Comment Return CmpTlsCreateContext2 RTS_IEC_HANDLE Handle to the new accepted socket or RTS_INVALID_HANDLE if failed. Input hCert RTS_IEC_HANDLE RTS_INVALID_HANDLE Handle to a certificate. The private key of this certificate has to be available. Can be RTS_INVALID_HANDLE for client connections. If the server requires a client certificate the connection will fail in these case. tlsMethod CmpTls_Interfaces.CmpTlsMethod Protocol version and role in the communication. TLS1.2 is suggested for new implementations. Default will be TLS1.2 client. cipherList POINTER TO STRING 0 Allowed chipers used by this connection. Leave 0 to get default. Default will result in ciphers with HIGH encryption strength and Diffie Hellman key exchange. verifyMode DWORD Set up how to verify the peer. The settings differ between client and server. See CmpTlsVerifyMode for details. Default results in: Client -> Verify the peer. Server -> Do not Verify Peer The options of CmpTlsConstans can be combined by adding them. verifyCallback CmpTls_Interfaces.IVerifyCertCallback This callback is called after the pre verification of the peers certificate. All possible checks (validity, trust chain, etc.) have been done already. The result of this check is passed to the callback. The callback allows to do futher checks (e.g. check the certificate host name, key usage etc.) depending on the use case of the connection. pResult POINTER TO RTS_IEC_RESULT Operations Result

CmpTlsFreeContext (FUN) ¶ FUNCTION CmpTlsFreeContext : RTS_IEC_RESULT This function cleans up the TLS context created with CmpTlsCreateContext. InOut: Scope Name Type Comment Return CmpTlsFreeContext RTS_IEC_RESULT Input hTlsContext RTS_IEC_HANDLE Handle to the context to clean up