(VB.NET) Duplicate openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

1. Creates a SHA256 digest of the contents of the input file
2. Signs the SHA256 digest using the private key.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim pkey As New Chilkat.PrivateKey

' Load the private key from an PEM file:
Dim success As Boolean = pkey.LoadPemFile("private.pem")
If (success <> True) Then
    Debug.WriteLine(pkey.LastErrorText)
    Exit Sub
End If


Dim rsa As New Chilkat.Rsa

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


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

' Load the file to be signed.
Dim bdFileData As New Chilkat.BinData
success = bdFileData.LoadFile("in.dat")

Dim bdSig As New Chilkat.BinData
success = rsa.SignBd(bdFileData,"sha256",bdSig)
If (success <> True) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If


' Save the binary signature to a file.
success = bdSig.WriteFile("signature.sig")
If (success <> True) Then
    Debug.WriteLine("Failed to write signature.sig.")
    Exit Sub
End If


Debug.WriteLine("Success.")