(Visual Basic 6.0) Generate RSA Key and Export to PKCS1 / PKCS8

Visual Basic 6.0 example code showing how to generate an RSA public/private key and save to PKCS1 and PKCS8 format files. In a PKCS1 or PKCS8 formatted file, the key is stored in binary ASN.1 format (and ASN.1 is itself written according to DER -- Distinguished Encoding Rules). A PEM file simply contains the binary ASN.1 base64 encoded and delimited by BEGIN/END lines. PKCS1 format files are never encrypted. PKCS8 can be encrypted or unencrypted. Public keys are never encrypted (there is no need). Private keys *should* always be encrypted - unless perhaps the unencrypted private key is obtained and itself stored in some sort of secure place.

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

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

Dim rsa As New ChilkatRsa

' Generate a 2048-bit key.  Chilkat RSA supports
' key sizes ranging from 512 bits to 8192 bits.
Dim success As Long
success = rsa.GenerateKey(2048)
If (success <> 1) Then
    Debug.Print rsa.LastErrorText
    Exit Sub
End If

' Get the public and private key parts:
Dim pubKey As PublicKey
Set pubKey = rsa.ExportPublicKeyObj()
Dim privKey As PrivateKey
Set privKey = rsa.ExportPrivateKeyObj()

' Get the public key as a PKCS8 PEM string
Dim pubKeyPem As String
pubKeyPem = pubKey.GetPem(0)
Debug.Print pubKeyPem

' Get the public key in PKCS8 format, in a Base64 encoded string.
Dim pubKeyPkcs8Base64 As String
pubKeyPkcs8Base64 = pubKey.GetEncoded(0,"base64")
Debug.Print pubKeyPkcs8Base64

' Get the public key in PKCS1 format, in a Base64 encoded string.
Dim pubKeyPkcs1Base64 As String
pubKeyPkcs1Base64 = pubKey.GetEncoded(1,"base64")
Debug.Print pubKeyPkcs1Base64

' Get the private key in a PKCS8 PEM string.
Dim privKeyPem As String
privKeyPem = privKey.GetPkcs8Pem()
Debug.Print privKeyPem

' Get the private key in a PKCS8 encrypted PEM string.
Dim privKeyEncPem As String
privKeyEncPem = privKey.GetPkcs8EncryptedPem("myPassword")
Debug.Print privKeyEncPem

' Get the private key in PKCS1 Base64 format
Dim privKeyPkcs1Base64 As String
privKeyPkcs1Base64 = privKey.GetPkcs1ENC("base64")
Debug.Print privKeyPkcs1Base64

' Get the private key in PKCS8 Base64 format
Dim privKeyPkcs8Base64 As String
privKeyPkcs8Base64 = privKey.GetPkcs8ENC("base64")
Debug.Print privKeyPkcs8Base64

' Save to PKCS1 / PKCS8 / PEM files...

' Save the public key to PKCS8 binary DER
success = pubKey.SaveDerFile(0,"pubKey_pkcs8.der")

' Save the public key to PKCS1 binary DER
success = pubKey.SaveDerFile("pubKey_pkcs1.der")

' Save the private key to unencrypted binary PKCS1 DER.
' Note: PKCS1 is never found in an encrypted format. 
success = privKey.SavePkcs1File("privKey_pkcs1.der")

' Save the private key to unencrypted binary PKCS8
success = privKey.SavePkcs8File("privKey_pkcs8.der")

' Save the private key to encrypted binary PKCS8
success = privKey.SavePkcs8EncryptedFile("myPassword","privKey_enc_pkcs8.der")

' Save the private key to unencrypted PKCS8 PEM
success = privKey.SavePkcs8PemFile("privKey.pem")

' Save the private key to encrypted PKCS8 PEM
success = privKey.SavePkcs8EncryptedPemFile("myPassword","privKey_enc.pem")