B4X

Generate RSA Key for SFTP

See more SSH Key Examples

Generates an 2048-bit RSA key for SSH/SFTP. Your application will use the generated private key. The public key is to be uploaded to the server and stored in the ".ssh" directory located under the HOME directory of the SSH/SFTP user account. B4X

Dim success As Boolean = False

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

Dim key As ChilkatSshKey
key.Initialize

Dim numBits As Int = 2048
Dim exponent As Int = 65537
success = key.GenerateRsaKey(numBits, exponent)
If success <> True Then
    Log("Bad params passed to RSA key generation method.")
    Return
End If


'  Note: Generating a public/private key pair is CPU intensive
'  and may take a short amount of time (more than few seconds,
'  but less than a minute).

Dim exportedKey As String
Dim exportEncrypted As Boolean

'  Export the RSA private key to encrypted PuTTY format:
key.Password = "secret"
exportEncrypted = True
exportedKey = key.ToPuttyPrivateKey(exportEncrypted)
success = key.SaveText(exportedKey, "qa_output/rsa_privkey_putty_encrypted.ppk")

'  Export the public key to openSSH format..
exportedKey = key.ToOpenSshPublicKey
success = key.SaveText(exportedKey, "qa_output/id_rsa.pub")

'  Sample id_rsa.pub:
'  ssh-rsa
'  AAAAB3NzaC1yc2EAAAADAQABAAA.....6tK3+vjwX/YC9dIXUz2Z 

Log("Finished.  Upload the id_rsa.pub to your .ssh directory located on the SSH/SFTP server under your user account's HOME directory")
Log("(Your HOME directory is the default directory you are in when you login via an SSH terminal.)")

'  After the id_rsa.pub is uploaded to your user account on the SSH/SFTP server, you can authenticate using the private key.
'  Your application will load the private key (.ppk) as shown here: Load SSH/SFTP Private Key .ppk
'  and then authenticate by calling AuthenticatePk (or AuthenticatePwPk).