AutoIt

RSA Signature/Verify with .key and .cer

See more RSA Examples

Demonstrates how to use a .key file (private key) and digital certificate (.cer, public key) to create and verify an RSA signature. AutoIt

Local $bSuccess = False

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

$oPrivKey = ObjCreate("Chilkat.PrivateKey")

; Load the private key from an RSA .key file:
$bSuccess = $oPrivKey.LoadPemFile("privateKey.key")
If ($bSuccess = False) Then
    ConsoleWrite($oPrivKey.LastErrorText & @CRLF)
    Exit
EndIf

$oRsa = ObjCreate("Chilkat.Rsa")

; Import the private key into the RSA component:
$bSuccess = $oRsa.UsePrivateKey($oPrivKey)
If ($bSuccess = False) Then
    ConsoleWrite($oRsa.LastErrorText & @CRLF)
    Exit
EndIf

; Create the signature as a hex string:
$oRsa.EncodingMode = "hex"

Local $strData = "This is the string to be signed."

; Sign the string using the sha256 hash algorithm.
; Other valid choices are "md2", "sha1", "sha384",
; "sha512", and "md5".
Local $sHexSig = $oRsa.SignStringENC($strData,"sha256")

ConsoleWrite($sHexSig & @CRLF)

; Load a digital certificate from a .cer file:
$oCert = ObjCreate("Chilkat.Cert")

$bSuccess = $oCert.LoadFromFile("myCert.cer")
If ($bSuccess = False) Then
    ConsoleWrite($oCert.LastErrorText & @CRLF)
    Exit
EndIf

$oPubKey = ObjCreate("Chilkat.PublicKey")
$oCert.GetPublicKey($oPubKey)

; Now verify using a new instance of the RSA object:
$oRsa2 = ObjCreate("Chilkat.Rsa")

; Import the public key into the RSA object:
$bSuccess = $oRsa2.UsePublicKey($oPubKey)
If ($bSuccess = False) Then
    ConsoleWrite($oRsa2.LastErrorText & @CRLF)
    Exit
EndIf

; The signature is a hex string, so make sure the EncodingMode is correct:
$oRsa2.EncodingMode = "hex"

; Verify the signature:
$bSuccess = $oRsa2.VerifyStringENC($strData,"sha256",$sHexSig)
If ($bSuccess = False) Then
    ConsoleWrite($oRsa2.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("Success." & @CRLF)