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xs/hkexshd/hkexshd.go

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// hkexshd server
//
// Copyright (c) 2017-2018 Russell Magee
// Licensed under the terms of the MIT license (see LICENSE.mit in this
// distribution)
//
// golang implementation by Russ Magee (rmagee_at_gmail.com)
package main
import (
"bytes"
"crypto/rand"
"encoding/binary"
"encoding/hex"
"errors"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"os"
"os/exec"
"os/signal"
"os/user"
"path"
"sync"
"syscall"
"unsafe"
"blitter.com/go/goutmp"
hkexsh "blitter.com/go/hkexsh"
"blitter.com/go/hkexsh/hkexnet"
"blitter.com/go/hkexsh/logger"
"github.com/kr/pty"
)
var (
version string
gitCommit string // set in -ldflags by build
useSysLogin bool
// Log - syslog output (with no -d)
Log *logger.Writer
)
func ioctl(fd, request, argp uintptr) error {
if _, _, e := syscall.Syscall6(syscall.SYS_IOCTL, fd, request, argp, 0, 0, 0); e != 0 {
return e
}
return nil
}
func ptsName(fd uintptr) (string, error) {
var n uintptr
err := ioctl(fd, syscall.TIOCGPTN, uintptr(unsafe.Pointer(&n)))
if err != nil {
return "", err
}
return fmt.Sprintf("/dev/pts/%d", n), nil
}
/* -------------------------------------------------------------- */
// Perform a client->server copy
func runClientToServerCopyAs(who, ttype string, conn *hkexnet.Conn, fpath string, chaffing bool) (exitStatus uint32, err error) {
u, _ := user.Lookup(who) // nolint: gosec
var uid, gid uint32
fmt.Sscanf(u.Uid, "%d", &uid) // nolint: gosec,errcheck
fmt.Sscanf(u.Gid, "%d", &gid) // nolint: gosec,errcheck
log.Println("uid:", uid, "gid:", gid)
// Need to clear server's env and set key vars of the
// target user. This isn't perfect (TERM doesn't seem to
// work 100%; ANSI/xterm colour isn't working even
// if we set "xterm" or "ansi" here; and line count
// reported by 'stty -a' defaults to 24 regardless
// of client shell window used to run client.
// Investigate -- rlm 2018-01-26)
os.Clearenv()
os.Setenv("HOME", u.HomeDir) // nolint: gosec,errcheck
os.Setenv("TERM", ttype) // nolint: gosec,errcheck
os.Setenv("HKEXSH", "1") // nolint: gosec,errcheck
var c *exec.Cmd
cmdName := "/bin/tar"
var destDir string
if path.IsAbs(fpath) {
destDir = fpath
} else {
destDir = path.Join(u.HomeDir, fpath)
}
cmdArgs := []string{"-xz", "-C", destDir}
// NOTE the lack of quotes around --xform option's sed expression.
// When args are passed in exec() format, no quoting is required
// (as this isn't input from a shell) (right? -rlm 20180823)
//cmdArgs := []string{"-x", "-C", destDir, `--xform=s#.*/\(.*\)#\1#`}
c = exec.Command(cmdName, cmdArgs...) // nolint: gosec
c.Dir = destDir
//If os.Clearenv() isn't called by server above these will be seen in the
//client's session env.
//c.Env = []string{"HOME=" + u.HomeDir, "SUDO_GID=", "SUDO_UID=", "SUDO_USER=", "SUDO_COMMAND=", "MAIL=", "LOGNAME="+who}
//c.Dir = u.HomeDir
c.SysProcAttr = &syscall.SysProcAttr{}
c.SysProcAttr.Credential = &syscall.Credential{Uid: uid, Gid: gid}
c.Stdin = conn
c.Stdout = os.Stdout
c.Stderr = os.Stderr
if chaffing {
conn.EnableChaff()
}
defer conn.DisableChaff()
defer conn.ShutdownChaff()
// Start the command (no pty)
log.Printf("[%v %v]\n", cmdName, cmdArgs)
err = c.Start() // returns immediately
/////////////
// NOTE: There is, apparently, a bug in Go stdlib here. Start()
// can actually return immediately, on a command which *does*
// start but exits quickly, with c.Wait() error
// "c.Wait status: exec: not started".
// As in this example, attempting a client->server copy to
// a nonexistent remote dir (it's tar exiting right away, exitStatus
// 2, stderr
// /bin/tar -xz -C /home/someuser/nosuchdir
// stderr: fork/exec /bin/tar: no such file or directory
//
// In this case, c.Wait() won't give us the real
// exit status (is it lost?).
/////////////
if err != nil {
log.Println("cmd exited immediately. Cannot get cmd.Wait().ExitStatus()")
err = errors.New("cmd exited prematurely")
//exitStatus = uint32(254)
exitStatus = hkexnet.CSEExecFail
} else {
if err := c.Wait(); err != nil {
//fmt.Println("*** c.Wait() done ***")
if exiterr, ok := err.(*exec.ExitError); ok {
// The program has exited with an exit code != 0
// This works on both Unix and Windows. Although package
// syscall is generally platform dependent, WaitStatus is
// defined for both Unix and Windows and in both cases has
// an ExitStatus() method with the same signature.
if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
exitStatus = uint32(status.ExitStatus())
//err = errors.New("cmd returned nonzero status")
log.Printf("Exit Status: %d\n", exitStatus)
}
}
}
log.Println("*** client->server cp finished ***")
}
return
}
// Perform a server->client copy
func runServerToClientCopyAs(who, ttype string, conn *hkexnet.Conn, srcPath string, chaffing bool) (exitStatus uint32, err error) {
u, err := user.Lookup(who)
if err != nil {
exitStatus = 1
return
}
var uid, gid uint32
_, _ = fmt.Sscanf(u.Uid, "%d", &uid) // nolint: gosec
_, _ = fmt.Sscanf(u.Gid, "%d", &gid) // nolint: gosec
log.Println("uid:", uid, "gid:", gid)
// Need to clear server's env and set key vars of the
// target user. This isn't perfect (TERM doesn't seem to
// work 100%; ANSI/xterm colour isn't working even
// if we set "xterm" or "ansi" here; and line count
// reported by 'stty -a' defaults to 24 regardless
// of client shell window used to run client.
// Investigate -- rlm 2018-01-26)
os.Clearenv()
_ = os.Setenv("HOME", u.HomeDir) // nolint: gosec
_ = os.Setenv("TERM", ttype) // nolint: gosec
_ = os.Setenv("HKEXSH", "1") // nolint: gosec
var c *exec.Cmd
cmdName := "/bin/tar"
if !path.IsAbs(srcPath) {
srcPath = fmt.Sprintf("%s%c%s", u.HomeDir, os.PathSeparator, srcPath)
}
srcDir, srcBase := path.Split(srcPath)
cmdArgs := []string{"-cz", "-C", srcDir, "-f", "-", srcBase}
c = exec.Command(cmdName, cmdArgs...) // nolint: gosec
//If os.Clearenv() isn't called by server above these will be seen in the
//client's session env.
//c.Env = []string{"HOME=" + u.HomeDir, "SUDO_GID=", "SUDO_UID=", "SUDO_USER=", "SUDO_COMMAND=", "MAIL=", "LOGNAME="+who}
c.Dir = u.HomeDir
c.SysProcAttr = &syscall.SysProcAttr{}
c.SysProcAttr.Credential = &syscall.Credential{Uid: uid, Gid: gid}
c.Stdout = conn
// Stderr sinkholing (or buffering to something other than stdout)
// is important. Any extraneous output to tarpipe messes up remote
// side as it's expecting pure tar data.
// (For example, if user specifies abs paths, tar outputs
// "Removing leading '/' from path names")
stdErrBuffer := new(bytes.Buffer)
c.Stderr = stdErrBuffer
//c.Stderr = nil
if chaffing {
conn.EnableChaff()
}
//defer conn.Close()
defer conn.DisableChaff()
defer conn.ShutdownChaff()
// Start the command (no pty)
log.Printf("[%v %v]\n", cmdName, cmdArgs)
err = c.Start() // returns immediately
if err != nil {
log.Printf("Command finished with error: %v", err)
return hkexnet.CSEExecFail, err // !?
}
if err := c.Wait(); err != nil {
//fmt.Println("*** c.Wait() done ***")
if exiterr, ok := err.(*exec.ExitError); ok {
// The program has exited with an exit code != 0
// This works on both Unix and Windows. Although package
// syscall is generally platform dependent, WaitStatus is
// defined for both Unix and Windows and in both cases has
// an ExitStatus() method with the same signature.
if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
exitStatus = uint32(status.ExitStatus())
if len(stdErrBuffer.Bytes()) > 0 {
log.Print(stdErrBuffer)
}
log.Printf("Exit Status: %d", exitStatus)
}
}
}
//fmt.Println("*** server->client cp finished ***")
return
}
// Run a command (via default shell) as a specific user
//
// Uses ptys to support commands which expect a terminal.
// nolint: gocyclo
func runShellAs(who, hname, ttype, cmd string, interactive bool, conn *hkexnet.Conn, chaffing bool) (exitStatus uint32, err error) {
var wg sync.WaitGroup
u, err := user.Lookup(who)
if err != nil {
exitStatus = 1
return
}
var uid, gid uint32
_, _ = fmt.Sscanf(u.Uid, "%d", &uid) // nolint: gosec
_, _ = fmt.Sscanf(u.Gid, "%d", &gid) // nolint: gosec
log.Println("uid:", uid, "gid:", gid)
// Need to clear server's env and set key vars of the
// target user. This isn't perfect (TERM doesn't seem to
// work 100%; ANSI/xterm colour isn't working even
// if we set "xterm" or "ansi" here; and line count
// reported by 'stty -a' defaults to 24 regardless
// of client shell window used to run client.
// Investigate -- rlm 2018-01-26)
os.Clearenv()
_ = os.Setenv("HOME", u.HomeDir) // nolint: gosec
_ = os.Setenv("TERM", ttype) // nolint: gosec
_ = os.Setenv("HKEXSH", "1") // nolint: gosec
var c *exec.Cmd
if interactive {
if useSysLogin {
// Use the server's login binary (post-auth
// which is still done via our own bcrypt file)
// Things UNIX login does, like print the 'motd',
// and use the shell specified by /etc/passwd, will be done
// automagically, at the cost of another external tool
// dependency.
//
c = exec.Command("/bin/login", "-f", "-p", who) // nolint: gosec
} else {
c = exec.Command("/bin/bash", "-i", "-l") // nolint: gosec
}
} else {
c = exec.Command("/bin/bash", "-c", cmd) // nolint: gosec
}
//If os.Clearenv() isn't called by server above these will be seen in the
//client's session env.
//c.Env = []string{"HOME=" + u.HomeDir, "SUDO_GID=", "SUDO_UID=", "SUDO_USER=", "SUDO_COMMAND=", "MAIL=", "LOGNAME="+who}
c.Dir = u.HomeDir
c.SysProcAttr = &syscall.SysProcAttr{}
if useSysLogin {
// If using server's login binary, drop to user creds
// is taken care of by it.
c.SysProcAttr.Credential = &syscall.Credential{}
} else {
c.SysProcAttr.Credential = &syscall.Credential{Uid: uid, Gid: gid}
}
c.Stdin = conn
c.Stdout = conn
c.Stderr = conn
// Start the command with a pty.
ptmx, err := pty.Start(c) // returns immediately with ptmx file
if err != nil {
log.Println(err)
return hkexnet.CSEPtyExecFail, err
}
// Make sure to close the pty at the end.
// #gv:s/label=\"runShellAs\$1\"/label=\"deferPtmxClose\"/
defer func() {
//logger.LogDebug(fmt.Sprintf("[Exited process was %d]", c.Process.Pid))
_ = ptmx.Close()
}() // nolint: gosec
// get pty info for system accounting (who, lastlog)
pts, pe := ptsName(ptmx.Fd())
if pe != nil {
return hkexnet.CSEPtyGetNameFail, err
}
utmpx := goutmp.Put_utmp(who, pts, hname)
defer func() { goutmp.Unput_utmp(utmpx) }()
goutmp.Put_lastlog_entry("hkexsh", who, pts, hname)
log.Printf("[%s]\n", cmd)
if err != nil {
log.Printf("Command finished with error: %v", err)
} else {
// Watch for term resizes
// #gv:s/label=\"runShellAs\$2\"/label=\"termResizeWatcher\"/
go func() {
for sz := range conn.WinCh {
log.Printf("[Setting term size to: %v %v]\n", sz.Rows, sz.Cols)
pty.Setsize(ptmx, &pty.Winsize{Rows: sz.Rows, Cols: sz.Cols}) // nolint: gosec,errcheck
}
log.Println("*** WinCh goroutine done ***")
}()
// Copy stdin to the pty.. (bgnd goroutine)
// #gv:s/label=\"runShellAs\$3\"/label=\"stdinToPtyWorker\"/
go func() {
_, e := io.Copy(ptmx, conn)
if e != nil {
log.Println("** stdin->pty ended **:", e.Error())
} else {
log.Println("*** stdin->pty goroutine done ***")
}
}()
if chaffing {
conn.EnableChaff()
}
// #gv:s/label=\"runShellAs\$4\"/label=\"deferChaffShutdown\"/
defer func() {
conn.DisableChaff()
conn.ShutdownChaff()
}()
// ..and the pty to stdout.
// This may take some time exceeding that of the
// actual command's lifetime, so the c.Wait() below
// must synchronize with the completion of this goroutine
// to ensure all stdout data gets to the client before
// connection is closed.
wg.Add(1)
// #gv:s/label=\"runShellAs\$5\"/label=\"ptyToStdoutWorker\"/
go func() {
defer wg.Done()
_, e := io.Copy(conn, ptmx)
if e != nil {
log.Println("** pty->stdout ended **:", e.Error())
} else {
// The above io.Copy() will exit when the command attached
// to the pty exits
log.Println("*** pty->stdout goroutine done ***")
}
}()
if err := c.Wait(); err != nil {
//fmt.Println("*** c.Wait() done ***")
if exiterr, ok := err.(*exec.ExitError); ok {
// The program has exited with an exit code != 0
// This works on both Unix and Windows. Although package
// syscall is generally platform dependent, WaitStatus is
// defined for both Unix and Windows and in both cases has
// an ExitStatus() method with the same signature.
if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
exitStatus = uint32(status.ExitStatus())
log.Printf("Exit Status: %d", exitStatus)
}
}
conn.SetStatus(hkexnet.CSOType(exitStatus))
} else {
logger.LogDebug("*** Main proc has exited. ***")
// Background jobs still may be running; close the
// pty anyway, so the client can return before
// wg.Wait() below completes (Issue #18)
if interactive {
_ = ptmx.Close()
}
}
wg.Wait() // Wait on pty->stdout completion to client
}
return
}
// GenAuthToken generates a pseudorandom auth token for a specific
// user from a specific host to allow non-interactive logins.
func GenAuthToken(who string, connhost string) string {
//tokenA, e := os.Hostname()
//if e != nil {
// tokenA = "badhost"
//}
tokenA := connhost
tokenB := make([]byte, 64)
_, _ = rand.Read(tokenB) // nolint: gosec
return fmt.Sprintf("%s:%s", tokenA, hex.EncodeToString(tokenB))
}
// Demo of a simple server that listens and spawns goroutines for each
// connecting client. Note this code is identical to standard tcp
// server code, save for declaring 'hkex' rather than 'net'
// Listener and Conns. The KEx and encrypt/decrypt is done within the type.
// Compare to 'serverp.go' in this directory to see the equivalence.
// TODO: reduce gocyclo
func main() {
var vopt bool
var chaffEnabled bool
var chaffFreqMin uint
var chaffFreqMax uint
var chaffBytesMax uint
var dbg bool
var laddr string
flag.BoolVar(&vopt, "v", false, "show version")
flag.StringVar(&laddr, "l", ":2000", "interface[:port] to listen")
flag.BoolVar(&useSysLogin, "L", false, "use system login")
flag.BoolVar(&chaffEnabled, "e", true, "enable chaff pkts")
flag.UintVar(&chaffFreqMin, "f", 100, "chaff pkt freq min (msecs)")
flag.UintVar(&chaffFreqMax, "F", 5000, "chaff pkt freq max (msecs)")
flag.UintVar(&chaffBytesMax, "B", 64, "chaff pkt size max (bytes)")
flag.BoolVar(&dbg, "d", false, "debug logging")
flag.Parse()
if vopt {
fmt.Printf("version %s (%s)\n", version, gitCommit)
os.Exit(0)
}
{
me, e := user.Current()
if e != nil || me.Uid != "0" {
log.Fatal("Must run as root.")
}
}
// Enforce some sane min/max vals on chaff flags
if chaffFreqMin < 2 {
chaffFreqMin = 2
}
if chaffFreqMax == 0 {
chaffFreqMax = chaffFreqMin + 1
}
if chaffBytesMax == 0 || chaffBytesMax > 4096 {
chaffBytesMax = 64
}
Log, _ = logger.New(logger.LOG_DAEMON|logger.LOG_DEBUG|logger.LOG_NOTICE|logger.LOG_ERR, "hkexshd") // nolint: gosec
hkexnet.Init(dbg, "hkexshd", logger.LOG_DAEMON|logger.LOG_DEBUG|logger.LOG_NOTICE|logger.LOG_ERR)
if dbg {
log.SetOutput(Log)
} else {
log.SetOutput(ioutil.Discard)
}
// Set up handler for daemon signalling
exitCh := make(chan os.Signal, 1)
signal.Notify(exitCh, os.Signal(syscall.SIGTERM), os.Signal(syscall.SIGINT), os.Signal(syscall.SIGHUP), os.Signal(syscall.SIGUSR1), os.Signal(syscall.SIGUSR2))
go func() {
for {
sig := <-exitCh
switch sig.String() {
case "terminated":
logger.LogNotice(fmt.Sprintf("[Got signal: %s]", sig)) // nolint: gosec,errcheck
signal.Reset()
syscall.Kill(0, syscall.SIGTERM) // nolint: gosec,errcheck
case "interrupt":
logger.LogNotice(fmt.Sprintf("[Got signal: %s]", sig)) // nolint: gosec,errcheck
signal.Reset()
syscall.Kill(0, syscall.SIGINT) // nolint: gosec,errcheck
case "hangup":
logger.LogNotice(fmt.Sprintf("[Got signal: %s - nop]", sig)) // nolint:gosec,errcheck
default:
logger.LogNotice(fmt.Sprintf("[Got signal: %s - ignored]", sig)) // nolint: gosec,errcheck
}
}
}()
// Listen on TCP port 2000 on all available unicast and
// anycast IP addresses of the local system.
l, err := hkexnet.Listen("tcp", laddr)
if err != nil {
log.Fatal(err)
}
defer l.Close() // nolint: errcheck
log.Println("Serving on", laddr)
for {
// Wait for a connection.
conn, err := l.Accept()
if err != nil {
log.Printf("Accept() got error(%v), hanging up.\n", err)
} else {
log.Println("Accepted client")
// Set up chaffing to client
// Will only start when runShellAs() is called
// after stdin/stdout are hooked up
conn.SetupChaff(chaffFreqMin, chaffFreqMax, chaffBytesMax) // configure server->client chaffing
// Handle the connection in a new goroutine.
// The loop then returns to accepting, so that
// multiple connections may be served concurrently.
go func(hc *hkexnet.Conn) (e error) {
defer hc.Close() // nolint: errcheck
//We use io.ReadFull() here to guarantee we consume
//just the data we want for the hkexsh.Session, and no more.
//Otherwise data will be sitting in the channel that isn't
//passed down to the command handlers.
var rec hkexsh.Session
var len1, len2, len3, len4, len5, len6 uint32
n, err := fmt.Fscanf(hc, "%d %d %d %d %d %d\n", &len1, &len2, &len3, &len4, &len5, &len6)
log.Printf("hkexsh.Session read:%d %d %d %d %d %d\n", len1, len2, len3, len4, len5, len6)
if err != nil || n < 6 {
log.Println("[Bad hkexsh.Session fmt]")
return err
}
tmp := make([]byte, len1)
_, err = io.ReadFull(hc, tmp)
if err != nil {
log.Println("[Bad hkexsh.Session.Op]")
return err
}
rec.SetOp(tmp)
tmp = make([]byte, len2)
_, err = io.ReadFull(hc, tmp)
if err != nil {
log.Println("[Bad hkexsh.Session.Who]")
return err
}
rec.SetWho(tmp)
tmp = make([]byte, len3)
_, err = io.ReadFull(hc, tmp)
if err != nil {
log.Println("[Bad hkexsh.Session.ConnHost]")
return err
}
rec.SetConnHost(tmp)
tmp = make([]byte, len4)
_, err = io.ReadFull(hc, tmp)
if err != nil {
log.Println("[Bad hkexsh.Session.TermType]")
return err
}
rec.SetTermType(tmp)
tmp = make([]byte, len5)
_, err = io.ReadFull(hc, tmp)
if err != nil {
log.Println("[Bad hkexsh.Session.Cmd]")
return err
}
rec.SetCmd(tmp)
tmp = make([]byte, len6)
_, err = io.ReadFull(hc, tmp)
if err != nil {
log.Println("[Bad hkexsh.Session.AuthCookie]")
return err
}
rec.SetAuthCookie(tmp)
log.Printf("[hkexsh.Session: op:%c who:%s connhost:%s cmd:%s auth:****]\n",
rec.Op()[0], string(rec.Who()), string(rec.ConnHost()), string(rec.Cmd()))
var valid bool
var allowedCmds string // Currently unused
if hkexsh.AuthUserByToken(string(rec.Who()), string(rec.ConnHost()), string(rec.AuthCookie(true))) {
valid = true
} else {
valid, allowedCmds = hkexsh.AuthUserByPasswd(string(rec.Who()), string(rec.AuthCookie(true)), "/etc/hkexsh.passwd")
}
// Security scrub
rec.ClearAuthCookie()
// Tell client if auth was valid
if valid {
hc.Write([]byte{1}) // nolint: gosec,errcheck
} else {
logger.LogNotice(fmt.Sprintln("Invalid user", string(rec.Who()))) // nolint: errcheck,gosec
hc.Write([]byte{0}) // nolint: gosec,errcheck
return
}
log.Printf("[allowedCmds:%s]\n", allowedCmds)
if rec.Op()[0] == 'A' {
// Generate automated login token
addr := hc.RemoteAddr()
hname := goutmp.GetHost(addr.String())
logger.LogNotice(fmt.Sprintf("[Generating autologin token for [%s@%s]]\n", rec.Who(), hname)) // nolint: gosec,errcheck
token := GenAuthToken(string(rec.Who()), string(rec.ConnHost()))
tokenCmd := fmt.Sprintf("echo \"%s\" | tee -a ~/.hkexsh_id", token)
cmdStatus, runErr := runShellAs(string(rec.Who()), hname, string(rec.TermType()), tokenCmd, false, hc, chaffEnabled)
// Returned hopefully via an EOF or exit/logout;
// Clear current op so user can enter next, or EOF
rec.SetOp([]byte{0})
if runErr != nil {
logger.LogErr(fmt.Sprintf("[Error generating autologin token for %s@%s]\n", rec.Who(), hname)) // nolint: gosec,errcheck
} else {
log.Printf("[Autologin token generation completed for %s@%s, status %d]\n", rec.Who(), hname, cmdStatus)
hc.SetStatus(hkexnet.CSOType(cmdStatus))
}
} else if rec.Op()[0] == 'c' {
// Non-interactive command
addr := hc.RemoteAddr()
hname := goutmp.GetHost(addr.String())
logger.LogNotice(fmt.Sprintf("[Running command for [%s@%s]]\n", rec.Who(), hname)) // nolint: gosec,errcheck
cmdStatus, runErr := runShellAs(string(rec.Who()), hname, string(rec.TermType()), string(rec.Cmd()), false, hc, chaffEnabled)
// Returned hopefully via an EOF or exit/logout;
// Clear current op so user can enter next, or EOF
rec.SetOp([]byte{0})
if runErr != nil {
logger.LogErr(fmt.Sprintf("[Error spawning cmd for %s@%s]\n", rec.Who(), hname)) // nolint: gosec,errcheck
} else {
logger.LogNotice(fmt.Sprintf("[Command completed for %s@%s, status %d]\n", rec.Who(), hname, cmdStatus)) // nolint: gosec,errcheck
hc.SetStatus(hkexnet.CSOType(cmdStatus))
}
} else if rec.Op()[0] == 's' {
// Interactive session
addr := hc.RemoteAddr()
hname := goutmp.GetHost(addr.String())
logger.LogNotice(fmt.Sprintf("[Running shell for [%s@%s]]\n", rec.Who(), hname)) // nolint: gosec,errcheck
cmdStatus, runErr := runShellAs(string(rec.Who()), hname, string(rec.TermType()), string(rec.Cmd()), true, hc, chaffEnabled)
// Returned hopefully via an EOF or exit/logout;
// Clear current op so user can enter next, or EOF
rec.SetOp([]byte{0})
if runErr != nil {
Log.Err(fmt.Sprintf("[Error spawning shell for %s@%s]\n", rec.Who(), hname)) // nolint: gosec,errcheck
} else {
logger.LogNotice(fmt.Sprintf("[Shell completed for %s@%s, status %d]\n", rec.Who(), hname, cmdStatus)) // nolint: gosec,errcheck
hc.SetStatus(hkexnet.CSOType(cmdStatus))
}
} else if rec.Op()[0] == 'D' {
// File copy (destination) operation - client copy to server
log.Printf("[Client->Server copy]\n")
addr := hc.RemoteAddr()
hname := goutmp.GetHost(addr.String())
logger.LogNotice(fmt.Sprintf("[Running copy for [%s@%s]]\n", rec.Who(), hname)) // nolint: gosec,errcheck
cmdStatus, runErr := runClientToServerCopyAs(string(rec.Who()), string(rec.TermType()), hc, string(rec.Cmd()), chaffEnabled)
// Returned hopefully via an EOF or exit/logout;
// Clear current op so user can enter next, or EOF
rec.SetOp([]byte{0})
if runErr != nil {
logger.LogErr(fmt.Sprintf("[Error running cp for %s@%s]\n", rec.Who(), hname)) // nolint: gosec,errcheck
} else {
logger.LogNotice(fmt.Sprintf("[Command completed for %s@%s, status %d]\n", rec.Who(), hname, cmdStatus)) // nolint: gosec,errcheck
}
hc.SetStatus(hkexnet.CSOType(cmdStatus))
// Send CSOExitStatus *before* client closes channel
s := make([]byte, 4)
binary.BigEndian.PutUint32(s, cmdStatus)
log.Printf("** cp writing closeStat %d at Close()\n", cmdStatus)
hc.WritePacket(s, hkexnet.CSOExitStatus) // nolint: gosec,errcheck
} else if rec.Op()[0] == 'S' {
// File copy (src) operation - server copy to client
log.Printf("[Server->Client copy]\n")
addr := hc.RemoteAddr()
hname := goutmp.GetHost(addr.String())
logger.LogNotice(fmt.Sprintf("[Running copy for [%s@%s]]\n", rec.Who(), hname)) // nolint: gosec,errcheck
cmdStatus, runErr := runServerToClientCopyAs(string(rec.Who()), string(rec.TermType()), hc, string(rec.Cmd()), chaffEnabled)
if runErr != nil {
logger.LogErr(fmt.Sprintf("[Error spawning cp for %s@%s]\n", rec.Who(), hname)) // nolint: gosec,errcheck
} else {
// Returned hopefully via an EOF or exit/logout;
logger.LogNotice(fmt.Sprintf("[Command completed for %s@%s, status %d]\n", rec.Who(), hname, cmdStatus)) // nolint: gosec,errcheck
}
// Clear current op so user can enter next, or EOF
rec.SetOp([]byte{0})
hc.SetStatus(hkexnet.CSOType(cmdStatus))
//fmt.Println("Waiting for EOF from other end.")
//_, _ = hc.Read(nil /*ackByte*/)
//fmt.Println("Got remote end ack.")
} else {
logger.LogErr(fmt.Sprintln("[Bad hkexsh.Session]")) // nolint: gosec,errcheck
}
return
}(&conn) // nolint: errcheck
} // Accept() success
} //endfor
//logger.LogNotice(fmt.Sprintln("[Exiting]")) // nolint: gosec,errcheck
}
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