DataFlex

Blowfish OFB Output Feedback Mode Encryption

See more Encryption Examples

Demonstrates how to encrypt using Blowfish OFB (Output Feedback) mode. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoCrypt
    String sIvHex
    String sKeyHex
    String sEncStr
    Handle hoDecrypt
    String sDecStr

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

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End

    // Use "blowfish2" to produce correct results that match published blowfish test vectors.
    Set ComCryptAlgorithm Of hoCrypt To "blowfish2"
    // Set the cipher mode to Output Feedback
    Set ComCipherMode Of hoCrypt To "ofb"
    Set ComKeyLength Of hoCrypt To 256

    // EncodingMode specifies the encoding of the output for
    // encryption, and the input for decryption.
    // It may be "hex", "url", "base64", "quoted-printable", or many other choices.
    Set ComEncodingMode Of hoCrypt To "hex"

    // The block size of the blowfish algoirthm is 8 bytes, therefore the IV is 8 bytes.
    Move "0001020304050607" To sIvHex
    Send ComSetEncodedIV To hoCrypt sIvHex "hex"

    // The secret key must equal the size of the key.  For
    // 256-bit encryption, the binary secret key is 32 bytes.
    Move "603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4" To sKeyHex
    Send ComSetEncodedKey To hoCrypt sKeyHex "hex"

    // Encrypt a string...
    Get ComEncryptStringENC Of hoCrypt "Emergencies have always been the pretext on which the safeguards of individual liberty have been eroded. -- Friedrich Hayek" To sEncStr
    Showln sEncStr

    Get Create (RefClass(cComChilkatCrypt2)) To hoDecrypt
    If (Not(IsComObjectCreated(hoDecrypt))) Begin
        Send CreateComObject of hoDecrypt
    End
    Set ComCryptAlgorithm Of hoDecrypt To "blowfish2"
    Set ComCipherMode Of hoDecrypt To "ofb"
    Set ComKeyLength Of hoDecrypt To 256
    Set ComEncodingMode Of hoDecrypt To "hex"
    Send ComSetEncodedIV To hoDecrypt sIvHex "hex"
    Send ComSetEncodedKey To hoDecrypt sKeyHex "hex"

    // Now decrypt:
    Get ComDecryptStringENC Of hoDecrypt sEncStr To sDecStr
    Showln sDecStr


End_Procedure