(DataFlex) Generate RSA Key and Sign a String

See more RSA Examples

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoRsa
    Boolean iSuccess
    String sStrData
    String sHexSig
    String sTemp1

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    Get Create (RefClass(cComChilkatRsa)) To hoRsa
    If (Not(IsComObjectCreated(hoRsa))) Begin
        Send CreateComObject of hoRsa
    End

    // Generate a 2048-bit RSA key.
    Get ComGenerateKey Of hoRsa 2048 To iSuccess

    // Return the signature in hex.
    Set ComEncodingMode Of hoRsa To "hex"

    Move "This is the string to be signed." To sStrData

    // Sign the SHA256 hash of the string.
    Get ComSignStringENC Of hoRsa sStrData "sha256" To sHexSig

    Showln sHexSig
    Get ComLastErrorText Of hoRsa To sTemp1
    Showln sTemp1

    // Now verify the signature:
    Get ComVerifyStringENC Of hoRsa sStrData "sha256" sHexSig To iSuccess
    If (iSuccess = True) Begin
        Showln "Signature verified!"
    End
    Else Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
    End

    // Try it with an invalid signature:
    Get ComVerifyStringENC Of hoRsa sStrData "sha256" "not a valid sig" To iSuccess
    If (iSuccess = True) Begin
        Showln "Signature verified!"
    End
    Else Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
    End

    // Try it with invalid data:
    Get ComVerifyStringENC Of hoRsa "Not the original data" "sha256" sHexSig To iSuccess
    If (iSuccess = True) Begin
        Showln "Signature verified!"
    End
    Else Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
    End

    // Try it with the wrong hash algorithm:
    Get ComVerifyStringENC Of hoRsa sStrData "sha-1" sHexSig To iSuccess
    If (iSuccess = True) Begin
        Showln "Signature verified!"
    End
    Else Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
    End



End_Procedure