pop3s_probe.go

// POP3S Tester
//
// The POP3S tester connects to a remote host and ensures that this
// succeeds.  If you supply a username & password a login will be
// made, and the test will fail if this login fails.
//
// This test is invoked via input like so:
//
//    host.example.com must run pop3 [with username 'steve@steve' with password 'secret']
//
// Because POP3S uses TLS it will test the validity of the certificate as
// part of the test, if you wish to disable this add `with tls insecure`.
//

package protocols

import (
	"crypto/tls"
	"fmt"
	"strconv"
	"strings"

	"github.com/simia-tech/go-pop3"
	"github.com/skx/overseer/test"
)

// POP3STest is our object
type POP3STest struct {
}

// Arguments returns the names of arguments which this protocol-test
// understands, along with corresponding regular-expressions to validate
// their values.
func (s *POP3STest) Arguments() map[string]string {
	known := map[string]string{
		"port":     "^[0-9]+$",
		"tls":      "insecure",
		"username": ".*",
		"password": ".*",
	}
	return known
}

// Example returns sample usage-instructions for self-documentation purposes.
func (s *POP3STest) Example() string {
	str := `
POP3S Tester
------------
 The POP3S tester connects to a remote host and ensures that this
 succeeds.  If you supply a username & password a login will be
 made, and the test will fail if this login fails.

 This test is invoked via input like so:

    host.example.com must run pop3

 Because POP3S uses TLS it will test the validity of the certificate as
 part of the test, if you wish to disable this add 'with tls insecure'.
`
	return str
}

// RunTest is the part of our API which is invoked to actually execute a
// test against the given target.
//
// In this case we make a POP3 connection to the specified host, and if
// a username + password were specified we then attempt to authenticate
// to the remote host too.
func (s *POP3STest) RunTest(tst test.Test, target string, opts test.Options) error {
	var err error

	//
	// The default port to connect to.
	//
	port := 995

	//
	// If the user specified a different port update to use it.
	//
	if tst.Arguments["port"] != "" {
		port, err = strconv.Atoi(tst.Arguments["port"])
		if err != nil {
			return err
		}
	}

	//
	// Should we skip validation of the SSL certificate?
	//
	insecure := false
	if tst.Arguments["tls"] == "insecure" {
		insecure = true
	}

	//
	// Default to connecting to an IPv4-address
	//
	address := fmt.Sprintf("%s:%d", target, port)

	//
	// If we find a ":" we know it is an IPv6 address though
	//
	if strings.Contains(target, ":") {
		address = fmt.Sprintf("[%s]:%d", target, port)
	}

	//
	// Setup the default TLS config.
	//
	// We need to setup the hostname that the TLS certificate
	// will verify upon, from our input-line.
	//
	data := strings.Fields(tst.Input)
	tlsSetup := &tls.Config{ServerName: data[0]}

	//
	// If we're being insecure then remove the verification
	//
	if insecure {
		tlsSetup = &tls.Config{
			InsecureSkipVerify: true,
		}
	}

	//
	// Connect
	//
	c, err := pop3.Dial(address, pop3.UseTLS(tlsSetup), pop3.UseTimeout(opts.Timeout))
	if err != nil {
		return err
	}

	//
	// Did we get a username/password?  If so try to authenticate
	// with them
	//
	if (tst.Arguments["username"] != "") && (tst.Arguments["password"] != "") {
		err = c.Auth(tst.Arguments["username"], tst.Arguments["password"])
		if err != nil {
			return err
		}
	}

	//
	// Quit and return
	//
	c.Quit()

	return nil
}

//
// Register our protocol-tester.
//
func init() {
	Register("pop3s", func() ProtocolTest {
		return &POP3STest{}
	})
}