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Demonstrate RSA Encrypt/Decrypt using BinData

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Demonstrates how to RSA encrypt and decrypt data contained in a Chilkat BinData object. AutoIt

Local $bSuccess = False

; The RSA public key is used for encryption, and the private key for decryption.

; The public key's role is to make encryption accessible to anyone while ensuring that
; only the private key holder can decrypt the messages.
; The public key is designed to be widely distributed so anyone can use it to encrypt messages
; intended for the owner of the private key.

; Load our 2048-bit RSA public key.
$oPubKey = ObjCreate("Chilkat.PublicKey")
; In all Chilkat methods expecting a path, you pass either absolute or relative paths.
$bSuccess = $oPubKey.LoadFromFile("rsaKeys/myTestRsaPublic.pem")
If ($bSuccess = False) Then
    ConsoleWrite($oPubKey.LastErrorText & @CRLF)
    Exit
EndIf

$oRsa = ObjCreate("Chilkat.Rsa")

; Tell RSA to use the public key.
$oRsa.UsePublicKey($oPubKey)

; RSA encryption is for small amounts of data, on the order of 200 bytes or less.
; The maximum number of bytes that can be RSA encrypted depends
; on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
; For specific limits, see: RSA Encryption Maximum Number of Bytes

; Create some binary data to encrypt.
$oBd = ObjCreate("Chilkat.BinData")
Local $i = 0
For $i = 0 To 49
    $oBd.AppendByte($i)
Next

; Show the bytes to be encrypted in hex format:
ConsoleWrite("To be encrypted: " & $oBd.GetEncoded("hex") & @CRLF)

; To be encrypted: 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F3031

; RSA encrypt the contents of the bd, replacing the contents with the RSA encrypted data.
$oRsa.EncryptBd($oBd,False)

; Now it is encrypted.
ConsoleWrite("Encrypted size = " & $oBd.NumBytes & @CRLF)
ConsoleWrite($oBd.GetEncoded("hex") & @CRLF)

; Encrypted size = 256
; 749ED9D0A8767C06C09AD9697F654F86B145F966722F9714902C4175BDBD02E68984ECF111D4D461
; EDB4A8E677D399D19CCA60F35C6DE9972F4262880FE9D77DB75915393E8E7DB80AAB5E383013FAEB
; 60C77D1E6FECC9A7C8426976416C6218FE7DA998EE063CE709E79C240F8625F4A56A0A33AFD63F7A
; BA26F2A692B42E878C53B78602C725FE63FF961A46A2B9D436E5E3D9D64AE3F1D1F5AD5F5B47FCD69
; 447306B77F2FD6D766CCAA1A110A3371586B43DF0D7FFE2220D1B305CF9371AC342F849FB0C90CD99E
; C176928D877FE1C0DE1A7CB6EB824FEC7E1DCF90EF2C6BA9F1DFD3EBFBE89C51AF074DC6AE02E544A78
; 5018C36D3D48B2EF5202AF61AC

; ------------------------------------------------------------------------------------------------------------------------
; Let's decrypt, which requires the matching private key...

; Load the matching 2048-bit RSA private key.
$oPrivKey = ObjCreate("Chilkat.PrivateKey")
Local $sPassword = "secret"
$bSuccess = $oPrivKey.LoadAnyFormatFile("rsaKeys/myTestRsaPrivate.pem",$sPassword)
If ($bSuccess = False) Then
    ConsoleWrite($oPrivKey.LastErrorText & @CRLF)
    Exit
EndIf

; Tell the RSA object to use the private key.
$oRsa.UsePrivateKey($oPrivKey)

; Decrypt
$bSuccess = $oRsa.DecryptBd($oBd,True)
If ($bSuccess = False) Then
    ConsoleWrite($oRsa.LastErrorText & @CRLF)
    Exit
EndIf

; Examine the contents of bd to see if it now contains the unencrypted original data.
ConsoleWrite("Decrypted: " & $oBd.GetEncoded("hex") & @CRLF)

; Decrypted: 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F3031