CONTROL
- Introduction to CTRL
- CONTROL Classes
- Types of Control Functions
- Control graphics
- CONTROL Functions
  - Funtions A
  - Funtions B
  - Funtions C
  - Funtions D
  - Functions E
    - exit()
      Terminates a manager and passes the exit code to the operating system.
    - errorDialog()
      Displays an error dialog.
    - ecdhGetPublicKey()
      The function stores the public key of the key pair for the ECDH key exchange.
    - errorText()
      Returns the text for the error code. This function should not be used anymore but remains included for reasons of compatibility. Instead of this function, use the functions getCatStr() or getErrorText(). These functions allow the definition of own error messages dependent on specific error codes. The error codes are saved in the file _errors.cat in the directory <wincc_oa_path>/msg/<lang>, respectively in the same file in the project directory.
    - ecdhDeriveSharedSecret()
      Generates a shared secret based on the key pair for an ECDH key exchange.
    - enumValues()
      The function returns the values of an enumeration as mapping.
    - execJsFunction()
      The function allows to call a JavaScript function from within the WebView EWO JavaScript code directly from CTRL.
    - eventPort()
      Returns the port number of the Event manager.
    - enableSound()
      Switches the sound of a wave file during runtime (see Configuration file).
    - execScriptRestricted()
      This function, like execScript(), allows for execution of a script during runtime. Use this function to run void main-functions which have no return value. Contrasting to execScript() the functions that can be used inside the executed script are limited to provide better security against insertion of malicious code.
    - ecdhReleaseKeyPair()
      The function releases a private/public key pair for an ECDH key exchange.
    - emSendMail() - obsolete
      This function allows sending mails.
    - execJsFunctionDyn()
      The function allows to call a JavaScript function from within the WebView EWO JavaScript code directly from CTRL.
    - evalScript()
      Allows to execute a script during runtime and to write the return value of the script in retVal.
    - enableMenuItem() - obsolete
      Supports disabling of menus (obsolete from version 3.5 up).
    - execScript()
      Allows to execute a script during runtime. Use this function for void main-functions (without return value).
    - emRetrieveMail()
      The function connects to a POP3 server and checks wether there are mails. If there are, the function retrieves the mails and deletes the mail at the server.
    - enumKeys()
      The function returns the list of keys that are available within the enumeration.
    - exp()
      Exponential function
    - eventHost()
      Returns the host name the event manager is running on.
    - evalScriptRestricted()
      Allows to execute a script during runtime and to write the return value of the script in target. Compared to the unrestricted function evalScript() only a more limited set of functions is allowed to provide better security.
    - ecdhGenerateKeyPair()
      The function generates a random private/public key pair for an ECDH key exchange.
  - Functions F
  - Functions G
  - Functions H
  - Functions I
  - Functions J
  - Functions K
  - Functions L
  - Functions M
  - Functions N
  - Functions O
  - Functions P
  - Functions Q
  - Functions R
  - Functions S
  - Functions T
  - Functions U
  - Functions V
  - Functions W
  - Functions X
  - Functions Y
  - Functions Z
- CTRL-Debugger
  Der CTRL-Debugger ermöglicht ein Debuggen der Pogrammiersprache Control.
- CtrlExtension

ecdhDeriveSharedSecret()

Generates a shared secret based on the key pair for an ECDH key exchange.

Synopsis

int ecdhDeriveSharedSecret(int keyPairId, blob &peerPublicKey, blob &sharedSecret)

Parameters


Parameter	Meaning
keyPairId	The key pair Id, generated with ecdhReleaseKeyPair().
peerPublicKey	The public key, extracted with ecdhGetPublicKey().
sharedSecret	Stores the shared secret.

Return value

The function returns 0 on success.

Error

In case of an error, an exception is thrown.

Description

Generates a shared secret based on the key pair with given ID, using the public key transferred from the peer as second argument. The shared secret will be stored in the third argument. If done correctly, the shared secret will be the same for both peers. Instead of using the secret directly, it should be hashed with cryptoHash() to achieve a better distribution of the generated data (for this, both peers need to use the same algorithm).

Anmerkung: The name of the ECDH curve to use can be configured with the already existing config entry [allSections] ECDHCurve.

Assignment

Communication functions

Availability

CTRL