(VBScript) Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

1. Creates a SHA256 digest of the contents of the input file.
2. Verifies the SHA256 digest using the public key.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

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

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.PublicKey")
set pubKey = CreateObject("Chilkat.PublicKey")

' Load the public key from an PEM file:
success = pubKey.LoadFromFile("pubKey.pem")
If (success <> 1) Then
    outFile.WriteLine(pubKey.LastErrorText)
    WScript.Quit
End If

' Load the data of the original file that was signed.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.BinData")
set bdFileData = CreateObject("Chilkat.BinData")
success = bdFileData.LoadFile("in.dat")

' Load the signature.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.BinData")
set bdSig = CreateObject("Chilkat.BinData")
success = bdSig.LoadFile("signature.sig")

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Rsa")
set rsa = CreateObject("Chilkat.Rsa")

' Import the public key into the RSA component:
success = rsa.ImportPublicKeyObj(pubKey)
If (success <> 1) Then
    outFile.WriteLine(rsa.LastErrorText)
    WScript.Quit
End If

' OpenSSL uses big-endian.
rsa.LittleEndian = 0

success = rsa.VerifyBd(bdFileData,"sha256",bdSig)
If (success <> 1) Then
    outFile.WriteLine(rsa.LastErrorText)
    outFile.WriteLine("The signature was invalid.")
    WScript.Quit
End If

outFile.WriteLine("The signature was verified.")

outFile.Close