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Ignore client connection closing - simpler challenge response error handling #18

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merged 1 commit into from
Mar 22, 2024
Merged

Ignore client connection closing - simpler challenge response error handling #18

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10 changes: 5 additions & 5 deletions docker-compose.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -15,8 +15,8 @@ services:
max-size: 10m
ports:
- '3000:3000'
image: 856da056de3abb7b317e59481bd500c27eb0f3b2a4c2432e8db930c1d20e71bf
container_name: ssh-sync-server-debug
image: b44427a64de93c20123c068387b0adc0434434ba709fbd91dd03d33ade489c3e
container_name: sshdbg
ssh-sync-db:
image: therealpaulgg/ssh-sync-db:latest
container_name: ssh-sync-db-debug
Expand All @@ -26,17 +26,17 @@ services:
- POSTGRES_DB=sshsync
restart: always
ssh-sync:
image: 9065faaa7a20a821f7323f42cbddac1b594f7d01d57f8b2a2837e433769b86f4
image: 62eab8fb32b34e0a2cf36e8635d810c20a38baa2d7beaf5b6918139339e23c23
container_name: ssh-sync
stdin_open: true # Allows Docker container to keep STDIN open
tty: true # Allocates a pseudo-TTY
ssh-sync-2:
image: 9065faaa7a20a821f7323f42cbddac1b594f7d01d57f8b2a2837e433769b86f4
image: 62eab8fb32b34e0a2cf36e8635d810c20a38baa2d7beaf5b6918139339e23c23
container_name: ssh-sync-2
stdin_open: true # Allows Docker container to keep STDIN open
tty: true # Allocates a pseudo-TTY
ssh-sync-3:
image: 9065faaa7a20a821f7323f42cbddac1b594f7d01d57f8b2a2837e433769b86f4
image: 62eab8fb32b34e0a2cf36e8635d810c20a38baa2d7beaf5b6918139339e23c23
container_name: ssh-sync-3
stdin_open: true # Allows Docker container to keep STDIN open
tty: true # Allocates a pseudo-TTY
Expand Down
60 changes: 18 additions & 42 deletions pkg/web/live/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,6 @@ package live
import (
"database/sql"
"errors"
"io"
"net"
"net/http"
"strings"
Expand Down Expand Up @@ -35,7 +34,7 @@ type ChallengeResponse struct {
ResponseChannel chan bool
}

type Something struct {
type ChallengeSession struct {
Username string
ChallengeAccepted chan bool
ChallengerChannel chan []byte
Expand All @@ -44,18 +43,18 @@ type Something struct {

type SafeChallengeResponseDict struct {
mux sync.Mutex
dict map[string]Something
dict map[string]ChallengeSession
}

// Utility method for safely writing to the dict
func (c *SafeChallengeResponseDict) WriteChallenge(challengePhrase string, data Something) {
func (c *SafeChallengeResponseDict) WriteChallenge(challengePhrase string, data ChallengeSession) {
c.mux.Lock()
c.dict[challengePhrase] = data
c.mux.Unlock()
}

// Utility method for safely reading from the dict
func (c *SafeChallengeResponseDict) ReadChallenge(challengePhrase string) (Something, bool) {
func (c *SafeChallengeResponseDict) ReadChallenge(challengePhrase string) (ChallengeSession, bool) {
c.mux.Lock()
data, exists := c.dict[challengePhrase]
c.mux.Unlock()
Expand All @@ -64,7 +63,7 @@ func (c *SafeChallengeResponseDict) ReadChallenge(challengePhrase string) (Somet

var ChallengeResponseChannel = make(chan ChallengeResponse)
var ChallengeResponseDict = SafeChallengeResponseDict{
dict: make(map[string]Something),
dict: make(map[string]ChallengeSession),
}

func MachineChallengeResponse(i *do.Injector, r *http.Request, w http.ResponseWriter) error {
Expand Down Expand Up @@ -107,6 +106,13 @@ func MachineChallengeResponseHandler(i *do.Injector, r *http.Request, w http.Res
// need a channel that both threads can access so that machine B can send public key to machine A
// and machine A can send back encrypted master key
key := <-chalChan.ChallengerChannel
if key == nil {
log.Debug().Msg("Response from challenger channel - key is nil. Exiting.")
if err := utils.WriteServerError[dto.ChallengeSuccessEncryptedKeyDto](&conn, "Error responding to challenge - client abruptly closed connection."); err != nil {
log.Err(err).Msg("Error writing server error")
}
return
}
keys := dto.ChallengeSuccessEncryptedKeyDto{
PublicKey: key,
}
Expand All @@ -133,25 +139,6 @@ func NewMachineChallenge(i *do.Injector, r *http.Request, w http.ResponseWriter)

func NewMachineChallengeHandler(i *do.Injector, r *http.Request, w http.ResponseWriter, c *net.Conn) {
conn := *c
defer conn.Close()
closeChan := make(chan struct{}) // Channel to signal connection closure

// Start a goroutine to monitor connection for closure
go func() {
buf := make([]byte, 1)

for {
_, err := conn.Read(buf)
if err != nil {
if err == io.EOF {
close(closeChan)
} else {
close(closeChan)
}
return
}
}
}()
// first message sent should be JSON payload
userMachine, err := utils.ReadClientMessage[dto.UserMachineDto](&conn)
if err != nil {
Expand Down Expand Up @@ -207,7 +194,7 @@ func NewMachineChallengeHandler(i *do.Injector, r *http.Request, w http.Response
// Computer A will receive the public key, decrypt the master key, encrypt the master key with the public key, and send it back to the server.
// At this point Computer B will be able to communicate freely.

ChallengeResponseDict.WriteChallenge(challengePhrase, Something{
ChallengeResponseDict.WriteChallenge(challengePhrase, ChallengeSession{
Username: user.Username,
ChallengeAccepted: make(chan bool),
ChallengerChannel: make(chan []byte),
Expand All @@ -225,6 +212,7 @@ func NewMachineChallengeHandler(i *do.Injector, r *http.Request, w http.Response
}
}()
timer := time.NewTimer(30 * time.Second)
challengeResponse := make(chan bool)
go func() {
var challengeAcceptedChan chan bool

Expand All @@ -243,26 +231,14 @@ func NewMachineChallengeHandler(i *do.Injector, r *http.Request, w http.Response
for {
select {
case <-timer.C:
ChallengeResponseDict.mux.Lock()
// Check if the challenge still exists before sending to the channel
if _, exists := ChallengeResponseDict.dict[challengePhrase]; exists {
ChallengeResponseDict.dict[challengePhrase].ChallengeAccepted <- false
}
ChallengeResponseDict.mux.Unlock()
challengeResponse <- false
return
case chalWon := <-challengeAcceptedChan:
log.Debug().Msg("Gorountine received challenge response")
if chalWon {
timer.Stop()
}
return
case <-closeChan:
log.Debug().Msg("Connection closed by client")
ChallengeResponseDict.mux.Lock()
// Check if the challenge still exists before sending to the channel
if _, exists := ChallengeResponseDict.dict[challengePhrase]; exists {
ChallengeResponseDict.dict[challengePhrase].ChallengeAccepted <- false
}
ChallengeResponseDict.mux.Unlock()
challengeResponse <- chalWon
return
}
}
Expand All @@ -272,7 +248,7 @@ func NewMachineChallengeHandler(i *do.Injector, r *http.Request, w http.Response
log.Err(err).Msg("Error getting challenge from dict")
return
}
challengeResult := <-cha.ChallengeAccepted
challengeResult := <-challengeResponse

if !challengeResult {
if err := utils.WriteServerError[dto.MessageDto](&conn, "Challenge timed out"); err != nil {
Expand Down
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