(Ruby) FTP Connect, Examine Server Certificate, and then Authenticate

Demonstrates how to connect to an FTP server, examine the server's SSL/TLS certificate, and then, if it meets the application's security requirements, proceed to authenticate.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example assumes Chilkat Ftp2 to have been previously unlocked.
# See Unlock Ftp2 for sample code.

ftp = Chilkat::CkFtp2.new()

ftp.put_Hostname("www.authtls-ftps-server.com")
ftp.put_Username("FTP_LOGIN")
ftp.put_Password("FTP_PASSWORD")
ftp.put_AuthTls(true)
ftp.put_Port(21)

# Connect to the FTP server using explicit TLS (AUTH TLS).
success = ftp.ConnectOnly()
if (success != true)
    print ftp.lastErrorText() + "\n";
    exit
end

# Get the FTP server's certificate.
# serverCert is a CkCert
serverCert = ftp.GetSslServerCert()
if (ftp.get_LastMethodSuccess() != true)
    print ftp.lastErrorText() + "\n";
    exit
end

# Now that we have the certificate, we can check it in any way we desire.
# (See the online reference documentation for the certificate object's methods
# and properties)...

# Assuming the certificate is OK, proceed to authenticate with the FTP server.
success = ftp.LoginAfterConnectOnly()
if (success != true)
    print ftp.lastErrorText() + "\n";
    exit
end

# 
# Proceed with uploading/download files, etc...
# 

ftp.Disconnect()
print "Success." + "\n";