(Excel) Duplicate openssl smime -decrypt -in some_file.dat.enc -binary -inform DER -inkey private.key -out some_file.dat

Demonstrates how to decrypt binary DER that was encrypted using the following openssl command:

openssl smime -encrypt -binary -aes-256-cbc -in some_file.dat -out some_file.dat.enc -outform DER cert.crt

Download Excel Class Modules Chilkat Excel Class Modules

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

' Duplicates the following openssl command:
' openssl smime -decrypt -in hello.txt.enc -binary -inform DER -inkey private.key -out hello.txt

Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert

success = cert.LoadFromFile("qa_data/openssl/EE.cer")
If (success = False) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

Dim bd As Chilkat.BinData
Set bd = Chilkat.NewBinData
success = bd.LoadFile("qa_data/openssl/EE.key")
' Assuming success..

Dim privKey As Chilkat.PrivateKey
Set privKey = Chilkat.NewPrivateKey
success = privKey.LoadAnyFormat(bd,"")
If (success = False) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

Dim crypt As Chilkat.Crypt2
Set crypt = Chilkat.NewCrypt2
success = crypt.SetDecryptCert2(cert,privKey)
If (success = False) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

crypt.CryptAlgorithm = "PKI"
success = crypt.CkDecryptFile("qa_data/openssl/hello.txt.enc","qa_output/hello.txt")
If (success = False) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

Debug.Print "Success."