(Swift 2) Manually Duplicate SetSecretKeyViaPassword

Demonstrates how to duplicate the password string to binary secret key computation of SetSecretKeyViaPassword.

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

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

    let crypt = CkoCrypt2()

    // The password string is transformed to a binary secret key by computing the 
    // MD5 digest (of the utf-8 password) to obtain 16 bytes.  
    // If the KeyLength is greater than 16 bytes, then the MD5 digest of the Base64 encoding 
    // of the utf-8 password is added.  A max of 32 bytes of key material is generated, and 
    // this is truncated to the actual KeyLength required.

    crypt.CryptAlgorithm = "aes"
    crypt.KeyLength = 256

    var password: String? = "this is my password"
    crypt.SetSecretKeyViaPassword(password)

    // Examine the resulting SecretKey in hex:
    print("Computed Secret Key = \(crypt.GetEncodedKey("hex"))")

    // Now perform the same computation manually:
    let sb = CkoStringBuilder()

    crypt.HashAlgorithm = "md5"
    crypt.Charset = "utf-8"
    crypt.EncodingMode = "hex"
    sb.Append(crypt.HashStringENC(password))

    var passwordBase64: String? = crypt.EncodeString(password, charset: "utf-8", encoding: "base64")
    sb.Append(crypt.HashStringENC(passwordBase64))

    print("Manually Computed = \(sb.GetAsString())")

    // The output is:
    // Computed Secret Key = 210D53992DFF432EC1B1A9698AF9DA16C7E90518F90E24828F78EC9E0A413B36
    // Manually Computed = 210D53992DFF432EC1B1A9698AF9DA16C7E90518F90E24828F78EC9E0A413B36

}