(Visual Basic 6.0) Export a Certificate's Private Key to Various Formats

Loads a digital certificate and private key from a PFX file (also known as PKCS#12) and exports the private key to various formats: (1) PKCS8 Encrypted, (2) PKCS8 Encrypted PEM, (3) PKCS8 unencrypted, (4) PKCS8 PEM unencrypted, (5) RSA DER unencrypted, (6) RSA PEM unencrypted, (7) XML.

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

Dim cert As New ChilkatCert

' Load from the PFX file
Dim pfxFilename As String
pfxFilename = "/Users/chilkat/testData/pfx/chilkat_ssl_pwd_is_test.pfx"
Dim pfxPassword As String
pfxPassword = "test"

' A PFX typically contains certificates in the chain of authentication.
' The Chilkat cert object will choose the certificate w/
' private key farthest from the root authority cert.
' To access all the certificates in a PFX, use the 
' Chilkat certificate store object instead.
Dim success As Long
success = cert.LoadPfxFile(pfxFilename,pfxPassword)
If (success <> 1) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Get the private key...
Dim privKey As PrivateKey
Set privKey = cert.ExportPrivateKey()
If (cert.LastMethodSuccess = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Export to various formats:

Dim password As String
password = "secret"
Dim path As String

' PKCS8 Encrypted DER
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.der"
success = privKey.SavePkcs8EncryptedFile(password,path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

' PKCS8 Encrypted PEM
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.pem"
success = privKey.SavePkcs8EncryptedPemFile(password,path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

' PKCS8 Unencrypted DER
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8.der"
success = privKey.SavePkcs8File(path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

' PKCS8 Unencrypted PEM
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8.pem"
success = privKey.SavePkcs8PemFile(path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

'  RSA DER (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat_rsa.der"
success = privKey.SavePkcs1File(path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

' RSA PEM (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat_rsa.pem"
success = privKey.SavePemFile(path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

' XML (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat.xml"
success = privKey.SaveXmlFile(path)
If (success <> 1) Then
    Debug.Print privKey.LastErrorText

    Exit Sub
End If

Debug.Print "Private key exported to all formats."