(Swift 3,4,5...) AES OFB Output Feedback Mode Encryption

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

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    let crypt = CkoCrypt2()!

    crypt.cryptAlgorithm = "aes"
    // Set the cipher mode to Output Feedback
    crypt.cipherMode = "ofb"
    crypt.keyLength = 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.
    crypt.encodingMode = "hex"

    var ivHex: String? = "000102030405060708090A0B0C0D0E0F"
    crypt.setEncodedIV(ivHex, encoding: "hex")

    // The secret key must equal the size of the key.  For
    // 256-bit encryption, the binary secret key is 32 bytes.
    var keyHex: String? = "603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4"
    crypt.setEncodedKey(keyHex, encoding: "hex")

    // Encrypt a string...
    var encStr: String? = crypt.encryptStringENC("Popular opinions, on subjects not palpable to sense, are often true, but seldom or never the whole truth. -- John Stuart Mill")
    print("\(encStr!)")

    let decrypt = CkoCrypt2()!
    decrypt.cryptAlgorithm = "aes"
    decrypt.cipherMode = "ofb"
    decrypt.keyLength = 256
    decrypt.encodingMode = "hex"
    decrypt.setEncodedIV(ivHex, encoding: "hex")
    decrypt.setEncodedKey(keyHex, encoding: "hex")

    // Now decrypt:
    var decStr: String? = decrypt.decryptStringENC(encStr)
    print("\(decStr!)")

}