B4X Requires Chilkat v11.0.0+

Generate RSA Key and Export to PKCS1 / PKCS8

See more RSA Examples

_LANGUAGE_ 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. B4X

Dim success As Boolean = False

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

Dim rsa As ChilkatRsa
rsa.Initialize

'  Generate a 2048-bit key.  Chilkat RSA supports
'  key sizes ranging from 512 bits to 8192 bits.
Dim privKey As ChilkatPrivateKey
privKey.Initialize("privKey")
success = rsa.GenKey(2048, privKey)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


'  Get the public key
Dim pubKey As ChilkatPublicKey
pubKey.Initialize
privKey.ToPublicKey(pubKey)

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

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

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

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

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

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

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

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

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