From 90e2e053d25feabd2dcf384dfc262a8bcdbe3ab8 Mon Sep 17 00:00:00 2001
From: Cody Hiar <cody@hiar.ca>
Date: Sat, 5 Mar 2022 12:53:15 -0700
Subject: Initial Commit

---
 termshare/internal/client.go_       | 86 +++++++++++++++++++++++++++++++++++++
 termshare/internal/daemon/daemon.go | 56 ++++++++++++++++++++++++
 termshare/internal/forwarder.go_    | 37 ++++++++++++++++
 3 files changed, 179 insertions(+)
 create mode 100644 termshare/internal/client.go_
 create mode 100644 termshare/internal/daemon/daemon.go
 create mode 100644 termshare/internal/forwarder.go_

(limited to 'termshare/internal')

diff --git a/termshare/internal/client.go_ b/termshare/internal/client.go_
new file mode 100644
index 0000000..1845a15
--- /dev/null
+++ b/termshare/internal/client.go_
@@ -0,0 +1,86 @@
+package main
+
+import (
+	"fmt"
+	"golang.org/x/crypto/ssh"
+	"log"
+	"os"
+	// Uncomment to store output in variable
+	//"bytes"
+)
+
+func main() {
+
+	username := "root"
+	password := ""
+	hostname := "127.0.0.1"
+	port := "2222"
+
+	// SSH client config
+	config := &ssh.ClientConfig{
+		User: username,
+		Auth: []ssh.AuthMethod{
+			ssh.Password(password),
+		},
+		// Non-production only
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+	}
+
+	// Connect to host
+	client, err := ssh.Dial("tcp", hostname+":"+port, config)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Close()
+
+	// Create sesssion
+	sess, err := client.NewSession()
+	if err != nil {
+		log.Fatal("Failed to create session: ", err)
+	}
+	defer sess.Close()
+
+	// StdinPipe for commands
+	stdin, err := sess.StdinPipe()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Uncomment to store output in variable
+	//var b bytes.Buffer
+	//sess.Stdout = &b
+	//sess.Stderr = &b
+
+	// Enable system stdout
+	// Comment these if you uncomment to store in variable
+	sess.Stdout = os.Stdout
+	sess.Stderr = os.Stderr
+
+	// Start remote shell
+	err = sess.Shell()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// send the commands
+	commands := []string{
+		"whoami",
+		"exit",
+	}
+	for _, cmd := range commands {
+		_, err = fmt.Fprintf(stdin, "%s\n", cmd)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	// Wait for sess to finish
+	err = sess.Wait()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Uncomment to store in variable
+	//fmt.Println(b.String())
+
+}
diff --git a/termshare/internal/daemon/daemon.go b/termshare/internal/daemon/daemon.go
new file mode 100644
index 0000000..465cdff
--- /dev/null
+++ b/termshare/internal/daemon/daemon.go
@@ -0,0 +1,56 @@
+package daemon
+
+import (
+	"fmt"
+    "bufio"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"syscall"
+    "strconv"
+	"unsafe"
+
+	"github.com/gliderlabs/ssh"
+	"github.com/creack/pty"
+)
+
+func setWinsize(f *os.File, w, h int) {
+	syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), uintptr(syscall.TIOCSWINSZ),
+		uintptr(unsafe.Pointer(&struct{ h, w, x, y uint16 }{uint16(h), uint16(w), 0, 0})))
+}
+
+func RunDaemon(port string) {
+	ssh.Handle(func(s ssh.Session) {
+		cmd := exec.Command("bash")
+		ptyReq, winCh, isPty := s.Pty()
+		if isPty {
+			cmd.Env = append(cmd.Env, fmt.Sprintf("TERM=%s", ptyReq.Term))
+			f, err := pty.Start(cmd)
+			if err != nil {
+				panic(err)
+			}
+			go func() {
+				for win := range winCh {
+					setWinsize(f, win.Width, win.Height)
+				}
+			}()
+			go func() {
+				io.Copy(f, s) // stdin
+			}()
+			io.Copy(s, f) // stdout
+			cmd.Wait()
+		} else {
+			io.WriteString(s, "No PTY requested.\n")
+            reader := bufio.NewReader(s)
+            for {
+                input, _, _ := reader.ReadRune()
+                io.WriteString(os.Stdout, strconv.QuoteRune(input))
+            }
+			s.Exit(1)
+		}
+	})
+
+	log.Println("starting ssh server on port " + port + " ...")
+  log.Fatal(ssh.ListenAndServe(":" + port, nil))
+}
diff --git a/termshare/internal/forwarder.go_ b/termshare/internal/forwarder.go_
new file mode 100644
index 0000000..2ce866f
--- /dev/null
+++ b/termshare/internal/forwarder.go_
@@ -0,0 +1,37 @@
+package main
+
+import (
+	"io"
+	"log"
+
+	"github.com/gliderlabs/ssh"
+)
+
+func main() {
+
+	log.Println("starting ssh server on port 2222...")
+
+	forwardHandler := &ssh.ForwardedTCPHandler{}
+
+	server := ssh.Server{
+		LocalPortForwardingCallback: ssh.LocalPortForwardingCallback(func(ctx ssh.Context, dhost string, dport uint32) bool {
+			log.Println("Accepted forward", dhost, dport)
+			return true
+		}),
+		Addr: ":2222",
+		Handler: ssh.Handler(func(s ssh.Session) {
+			io.WriteString(s, "Remote forwarding available...\n")
+			select {}
+		}),
+		ReversePortForwardingCallback: ssh.ReversePortForwardingCallback(func(ctx ssh.Context, host string, port uint32) bool {
+			log.Println("attempt to bind", host, port, "granted")
+			return true
+		}),
+		RequestHandlers: map[string]ssh.RequestHandler{
+			"tcpip-forward":        forwardHandler.HandleSSHRequest,
+			"cancel-tcpip-forward": forwardHandler.HandleSSHRequest,
+		},
+	}
+
+	log.Fatal(server.ListenAndServe())
+}
-- 
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