(Excel) Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim pkey As Chilkat.PrivateKey
Set pkey = Chilkat.NewPrivateKey

' Load the private key from an RSA PEM file:

success = pkey.LoadPemFile("myKey.pem")

' Get the private key in XML format:
pkeyXml = pkey.GetXml()

Dim rsa As Chilkat.Rsa
Set rsa = Chilkat.NewRsa

' Import the private key into the RSA component:
success = rsa.ImportPrivateKey(pkeyXml)
If (success <> True) Then
    Debug.Print rsa.LastErrorText
    Exit Sub
End If

' OpenSSL uses BigEndian byte ordering:
rsa.LittleEndian = False

' The resulting signature will be a Base64 string:
rsa.EncodingMode = "base64"

' For simplicity, we're not loading
' the data to be signed from a file.  We are instead simply
' using a literal string value.  

strData = "This is the text to be signed."

' Hash the input using MD5, and then sign the hash:
' Other valid hash algorithm choices are "md2" and "sha-1".

base64Sig = rsa.SignStringENC(strData,"md5")

Debug.Print base64Sig

Debug.Print "Success!"