Implement interactive shell #24

asimfarooq5 · 2025-09-20T11:24:45Z

No description provided.

muzzammilshahid · 2025-09-20T12:35:21Z

cmd/wshd/main.go

+			cmd := exec.Command("bash")
+			newPtmx, err := pty.Start(cmd)
+			if err != nil {
+				return xconn.NewInvocationError("io.xconn.error", err.Error())
+			}
+
+			ptmx = newPtmx
+			p.Lock()
+			p.ptmx[caller] = newPtmx
+			p.Unlock()
+
+			go func(inv *xconn.Invocation, ptmx *os.File) {
+				buf := make([]byte, 4096)
+				for {
+					n, err := ptmx.Read(buf)
+					if n > 0 {
+						ciphertext, nonce, errEnc := berncrypt.EncryptChaCha20Poly1305(buf[:n], key.Send)
+						if errEnc != nil {
+							log.Printf("Encryption failed in shell output: %v", errEnc)
+							break
+						}
+						payload := append(nonce, ciphertext...)
+						_ = inv.SendProgress([]any{payload}, nil)
+					}
+
+					if err != nil {
+						_ = inv.SendProgress(nil, nil)
+						break
+					}
+				}
+
+			}(inv, ptmx)
+			return xconn.NewInvocationError(xconn.ErrNoResult)
+


we can create a separate function for this may be called startPty or startTerminal

muzzammilshahid · 2025-09-20T12:41:00Z

cmd/wshd/main.go

-	var stdout, stderr bytes.Buffer
-	command := exec.Command(cmd, args...)
-	command.Stdout = &stdout
-	command.Stderr = &stderr
-	err := command.Run()
+	fullCmd := cmd
+	if len(args) > 0 {
+		fullCmd += " " + strings.Join(args, " ")
+	}
+	c := exec.Command("bash", "-ic", fullCmd)
+	ptmx, err := pty.Start(c)
 	if err != nil {
-		return stderr.Bytes(), err
+		return nil, err
 	}
+	defer func() { _ = ptmx.Close() }()
+
+	var stdout bytes.Buffer
+	_, _ = stdout.ReadFrom(ptmx)
+


not needed in this PR we already have a PR for that

muzzammilshahid · 2025-09-20T12:42:56Z

cmd/wsh/main.go

+	defer func(fd int, oldState *term.State) {
+		_ = term.Restore(fd, oldState)
+	}(fd, oldState)


Suggested change

defer func(fd int, oldState *term.State) {

_ = term.Restore(fd, oldState)

}(fd, oldState)

defer func() { _ = term.Restore(fd, oldState)}()

muzzammilshahid · 2025-09-20T12:44:06Z

cmd/wsh/main.go

+
+				plain, err := berncrypt.DecryptChaCha20Poly1305(encData[12:], encData[:12], keys.receive)
+				if err != nil {
+					panic(err)


return error instead

muzzammilshahid · 2025-09-20T12:47:08Z

cmd/wsh/main.go

+	}
+}
+
+func runCommand(session *xconn.Session, keys *keyPair, args []string) {


Suggested change

func runCommand(session *xconn.Session, keys *keyPair, args []string) {

func runCommand(session *xconn.Session, keys *keyPair, args []string) error {

muzzammilshahid · 2025-09-20T12:50:07Z

cmd/wsh/main.go

 	if err != nil {
-		fmt.Printf("Error creating crypto sign authenticator: %v\n", err)
+		fmt.Printf("Error creating crypto sign authenticator: %v", err)
 		os.Exit(1)


We can use log.Fatal

muzzammilshahid · 2025-09-22T07:36:00Z

cmd/wshd/main.go

+	p.ptmx[caller] = ptmx
+	p.Unlock()
+
+	p.startOutputReader(caller, inv, ptmx, sendKey)


Suggested change

p.startOutputReader(caller, inv, ptmx, sendKey)

go p.startOutputReader(inv, ptmx, sendKey)

and then we can remove the go routine inside the function

muzzammilshahid · 2025-09-22T07:43:20Z

cmd/wshd/main.go

+func (p *interactiveShellSession) startOutputReader(caller uint64,
+	inv *xconn.Invocation, ptmx *os.File, sendKey []byte) {
+	go func() {
+		defer func() {
+			p.Lock()
+			if stored, exists := p.ptmx[caller]; exists && stored == ptmx {
+				delete(p.ptmx, caller)
+			}
+			p.Unlock()
+			if err := ptmx.Close(); err != nil {
+				log.Printf("Error closing PTY for caller %d: %v", caller, err)
+			}
+		}()
+
+		buf := make([]byte, 4096)
+		for {
+			n, err := ptmx.Read(buf)
+			if n > 0 {
+				ciphertext, nonce, errEnc := berncrypt.EncryptChaCha20Poly1305(buf[:n], sendKey)
+				if errEnc != nil {
+					log.Printf("Encryption failed in shell output for caller %d: %v", caller, errEnc)
+					return
+				}
+				payload := append(nonce, ciphertext...)
+				_ = inv.SendProgress([]any{payload}, nil)
+			}
+			if err != nil {
+				_ = inv.SendProgress(nil, nil)
+				return
+			}
+		}
+	}()
+}


Suggested change

func (p *interactiveShellSession) startOutputReader(caller uint64,

inv *xconn.Invocation, ptmx *os.File, sendKey []byte) {

go func() {

defer func() {

p.Lock()

if stored, exists := p.ptmx[caller]; exists && stored == ptmx {

delete(p.ptmx, caller)

}

p.Unlock()

if err := ptmx.Close(); err != nil {

log.Printf("Error closing PTY for caller %d: %v", caller, err)

}

}()

buf := make([]byte, 4096)

for {

n, err := ptmx.Read(buf)

if n > 0 {

ciphertext, nonce, errEnc := berncrypt.EncryptChaCha20Poly1305(buf[:n], sendKey)

if errEnc != nil {

log.Printf("Encryption failed in shell output for caller %d: %v", caller, errEnc)

return

}

payload := append(nonce, ciphertext...)

_ = inv.SendProgress([]any{payload}, nil)

}

if err != nil {

_ = inv.SendProgress(nil, nil)

return

}

}

}()

}

func (p *interactiveShellSession) startOutputReader(inv *xconn.Invocation, ptmx *os.File, sendKey []byte) {

caller := inv.Caller()

defer func() {

p.Lock()

if stored, exists := p.ptmx[caller]; exists && stored == ptmx {

delete(p.ptmx, caller)

}

p.Unlock()

if err := ptmx.Close(); err != nil {

log.Printf("Error closing PTY for caller %d: %v", caller, err)

}

}()

buf := make([]byte, 4096)

for {

n, err := ptmx.Read(buf)

if n > 0 {

ciphertext, nonce, errEnc := berncrypt.EncryptChaCha20Poly1305(buf[:n], sendKey)

if errEnc != nil {

log.Printf("Encryption failed in shell output for caller %d: %v", caller, errEnc)

return

}

payload := append(nonce, ciphertext...)

_ = inv.SendProgress([]any{payload}, nil)

}

if err != nil {

_ = inv.SendProgress(nil, nil)

return

}

}

}

muzzammilshahid · 2025-09-22T07:44:10Z

cmd/wshd/main.go

+func (p *interactiveShellSession) startPtySession(caller uint64,
+	inv *xconn.Invocation, sendKey []byte) (*os.File, error) {
+	cmd := exec.Command("bash")
+	ptmx, err := pty.Start(cmd)
+	if err != nil {
+		return nil, fmt.Errorf("failed to start PTY: %w", err)
+	}
+
+	p.Lock()
+	p.ptmx[caller] = ptmx
+	p.Unlock()


Suggested change

func (p *interactiveShellSession) startPtySession(caller uint64,

inv *xconn.Invocation, sendKey []byte) (*os.File, error) {

cmd := exec.Command("bash")

ptmx, err := pty.Start(cmd)

if err != nil {

return nil, fmt.Errorf("failed to start PTY: %w", err)

}

p.Lock()

p.ptmx[caller] = ptmx

p.Unlock()

func (p *interactiveShellSession) startPtySession(inv *xconn.Invocation, sendKey []byte) (*os.File, error) {

cmd := exec.Command("bash")

ptmx, err := pty.Start(cmd)

if err != nil {

return nil, fmt.Errorf("failed to start PTY: %w", err)

}

p.Lock()

p.ptmx[inv.Caller()] = ptmx

p.Unlock()

muzzammilshahid · 2025-09-23T13:33:11Z

cmd/wshd/main.go

+		if stored, exists := p.ptmx[caller]; exists && stored == ptmx {
+			delete(p.ptmx, caller)
+		}


Suggested change

if stored, exists := p.ptmx[caller]; exists && stored == ptmx {

delete(p.ptmx, caller)

}

delete(p.ptmx, caller)

muzzammilshahid · 2025-09-23T13:35:37Z

cmd/wshd/main.go

+		}
+
+		p.Lock()
+		ptmx, ok = p.ptmx[caller]


Suggested change

ptmx, ok = p.ptmx[caller]

muzzammilshahid · 2025-09-23T13:36:43Z

cmd/wsh/main.go

 	}, nil
 }

+func startInteractiveShell(session *xconn.Session, keys *keyPair) {


Suggested change

func startInteractiveShell(session *xconn.Session, keys *keyPair) {

func startInteractiveShell(session *xconn.Session, keys *keyPair) error {

and change function accordingly

muzzammilshahid · 2025-09-23T13:38:27Z

cmd/wsh/main.go

+	}
+}
+
+func runCommand(session *xconn.Session, keys *keyPair, args []string) {


Suggested change

func runCommand(session *xconn.Session, keys *keyPair, args []string) {

func runCommand(session *xconn.Session, keys *keyPair, args []string) error {

and change function accordingly

asimfarooq5 requested review from muzzammilshahid and om26er September 20, 2025 11:25

muzzammilshahid requested changes Sep 20, 2025

View reviewed changes

om26er changed the title ~~Implement interactive shell support~~ Implement interactive shell Sep 20, 2025

asimfarooq5 requested a review from muzzammilshahid September 20, 2025 15:22

om26er force-pushed the feat/interactive-shell branch from ff45169 to 306e1da Compare September 21, 2025 19:16

asimfarooq5 added 4 commits September 22, 2025 00:29

Implement interactive shell support

7052870

Extract PTY session creation into startPtySession function

a80119c

refactor: errors

757724e

make lint happy

218b68d

om26er force-pushed the feat/interactive-shell branch from 306e1da to 218b68d Compare September 21, 2025 19:29

muzzammilshahid requested changes Sep 22, 2025

View reviewed changes

Implement interactive shell support

112bfc4

asimfarooq5 changed the title ~~Implement interactive shell~~ refactor: Suggested changes Sep 23, 2025

asimfarooq5 requested a review from muzzammilshahid September 23, 2025 13:06

asimfarooq5 changed the title ~~refactor: Suggested changes~~ Implement interactive shell Sep 23, 2025

muzzammilshahid requested changes Sep 23, 2025

View reviewed changes

Merge branch 'main' into feat/interactive-shell

2df0904

asimfarooq5 requested a review from muzzammilshahid September 23, 2025 15:00

muzzammilshahid approved these changes Sep 23, 2025

View reviewed changes

om26er merged commit 3e45ca3 into main Sep 23, 2025
1 check passed

om26er deleted the feat/interactive-shell branch September 23, 2025 15:16

	func runCommand(session xconn.Session, keys keyPair, args []string) {
	func runCommand(session xconn.Session, keys keyPair, args []string) error {

	p.startOutputReader(caller, inv, ptmx, sendKey)
	go p.startOutputReader(inv, ptmx, sendKey)

	func startInteractiveShell(session xconn.Session, keys keyPair) {
	func startInteractiveShell(session xconn.Session, keys keyPair) error {

Implement interactive shell #24

Implement interactive shell #24

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asimfarooq5 commented Sep 20, 2025

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muzzammilshahid Sep 22, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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muzzammilshahid Sep 22, 2025 •

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