B4X Requires Chilkat v11.0.0+

Convert RSA Private Key to Public Key

See more RSA Examples

Demonstrates how to get a public RSA key from a private RSA key. B4X

Dim success As Boolean = False

Dim privKey As ChilkatPrivateKey
privKey.Initialize("privKey")

'  Step 1: Load the private key from a source.
'  (Chilkat can load private keys from all types of formats, and from in-memory bytes or encoded strings.
'  see the online reference documentation for more options.)
success = privKey.LoadPemFile("qa_data/pem/VP_Private.pem")
If success = False Then
    Log(privKey.LastErrorText)
    Return
End If


'  Step 2: Get the public key object from the private key object.
Dim pubKey As ChilkatPublicKey
pubKey.Initialize
privKey.ToPublicKey(pubKey)

'  Step 3: Save the public key in a desired format. 
'  (Chilkat can load or save public and private keys in many different formats.  See
'  the online reference documentation for more options.)

'  Saves to a PKCS8 PEM file.
Dim bPreferPkcs1 As Boolean = False
success = pubKey.SavePemFile(bPreferPkcs1, "qa_data/pem/VP_Public.pem")
If pubKey.LastMethodSuccess = False Then
    Log(pubKey.LastErrorText)
    Return
End If


Log("Extracted and saved public key from private key.")