start adding ssh support

Signed-off-by: Jeff Carr <jcarr@wit.com>

ssh.go

@@ -0,0 +1,129 @@
+package shell
+
+import "bufio"
+import "log"
+import "fmt"
+import "os"
+import "os/user"
+import "io/ioutil"
+import "path/filepath"
+import "strings"
+import "time"
+
+import "golang.org/x/crypto/ssh"
+import "github.com/tmc/scp"
+
+func SSH(hostname string, port int, username string, pass string) *ssh.Session {
+//	username := "jcarr"
+//	pass := "tryme"
+	// cmd  := "ps"
+
+	// get host public key
+	// hostKey := getHostKey(host)
+	// log.Println("hostkey =", hostKey)
+
+	user, _ := user.Current()
+
+	publicKey, err := PublicKeyFile(user.HomeDir + "/.ssh/id_ed25519")
+	if (err != nil) {
+		log.Println("PublicKeyFile() error =", err)
+	}
+
+	// ssh client config
+	config := ssh.ClientConfig{
+		User: username,
+		Auth: []ssh.AuthMethod{
+			ssh.Password(pass),
+			publicKey,
+		},
+		// allow any host key to be used (non-prod)
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+
+		// verify host public key
+		// HostKeyCallback: ssh.FixedHostKey(hostKey),
+		// optional host key algo list
+		HostKeyAlgorithms: []string{
+			ssh.KeyAlgoRSA,
+			ssh.KeyAlgoDSA,
+			ssh.KeyAlgoECDSA256,
+			ssh.KeyAlgoECDSA384,
+			ssh.KeyAlgoECDSA521,
+			ssh.KeyAlgoED25519,
+		},
+		// optional tcp connect timeout
+		Timeout:         5 * time.Second,
+	}
+
+	sport := fmt.Sprintf("%d", port)
+	// connect
+	client, err := ssh.Dial("tcp", hostname+":"+sport, &config)
+	if err != nil {
+		log.Fatal(err)
+	}
+	// defer client.Close()
+
+	// start session
+	sess, err := client.NewSession()
+	if err != nil {
+		log.Fatal(err)
+	}
+	// defer sess.Close()
+	return sess
+}
+
+func Scp(sess *ssh.Session, localfile string, remotefile string) {
+	err := scp.CopyPath(localfile, remotefile, sess)
+	log.Println("scp.CopyPath() err =", err)
+}
+
+func getHostKey(host string) ssh.PublicKey {
+	// parse OpenSSH known_hosts file
+	// ssh or use ssh-keyscan to get initial key
+	file, err := os.Open(filepath.Join(os.Getenv("HOME"), ".ssh", "known_hosts"))
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	var hostKey ssh.PublicKey
+	for scanner.Scan() {
+		fields := strings.Split(scanner.Text(), " ")
+		if len(fields) != 3 {
+			continue
+		}
+		if strings.Contains(fields[0], host) {
+			var err error
+			hostKey, _, _, _, err = ssh.ParseAuthorizedKey(scanner.Bytes())
+			if err != nil {
+				log.Fatalf("error parsing %q: %v", fields[2], err)
+			}
+			break
+		}
+	}
+
+	// 9enFJdMhb8eHN/6qfHSU/jww2Mo=|pcsWQCvAyve9QXBhjL+w/LhkcHU= ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBMQx8BJXxD+vk3wyjy7Irzw4FA6xxJvqUP7Hb+Z+ygpOuidYj9G8x6gHEXFUnABn5YirePrWh5tNsk4Rqs48VwU=
+	hostKey, _, _, _, err = ssh.ParseAuthorizedKey([]byte("9enFJdMhb8eHN/6qfHSU/jww2Mo=|pcsWQCvAyve9QXBhjL+w/LhkcHU= ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBMQx8BJXxD+vk3wyjy7Irzw4FA6xxJvqUP7Hb+Z+ygpOuidYj9G8x6gHEXFUnABn5YirePrWh5tNsk4Rqs48VwU="))
+	log.Println("hostkey err =", err)
+	log.Println("hostkey =", hostKey)
+	if hostKey == nil {
+		log.Println("no hostkey found err =", err)
+		log.Fatalf("no hostkey found for %s", host)
+	}
+
+	return hostKey
+}
+
+func PublicKeyFile(file string) (ssh.AuthMethod, error) {
+	buffer, err := ioutil.ReadFile(file)
+	log.Println("buffer =", string(buffer))
+	if err != nil {
+		return nil, err
+	}
+
+	key, err := ssh.ParsePrivateKey(buffer)
+	if err != nil {
+		return nil, err
+	}
+	return ssh.PublicKeys(key), nil
+}