pam: web app access #151
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,200 @@ | ||
| package webapp | ||
|
|
||
| import ( | ||
| "bufio" | ||
| "bytes" | ||
| "context" | ||
| "crypto/tls" | ||
| "errors" | ||
| "fmt" | ||
| "io" | ||
| "net" | ||
| "net/http" | ||
| "time" | ||
|
|
||
| "github.com/Infisical/infisical-merge/packages/pam/session" | ||
| "github.com/google/uuid" | ||
| "github.com/rs/zerolog/log" | ||
| ) | ||
|
|
||
| type WebAppProxyConfig struct { | ||
| TargetAddr string | ||
| Protocol string // "http" or "https" | ||
| TLSConfig *tls.Config | ||
| SessionID string | ||
| SessionLogger session.SessionLogger | ||
| } | ||
|
|
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| type WebAppProxy struct { | ||
| config WebAppProxyConfig | ||
| } | ||
|
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| func NewWebAppProxy(config WebAppProxyConfig) *WebAppProxy { | ||
| return &WebAppProxy{config: config} | ||
| } | ||
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| func (p *WebAppProxy) HandleConnection(ctx context.Context, clientConn net.Conn) error { | ||
| defer clientConn.Close() | ||
|
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| sessionID := p.config.SessionID | ||
| l := log.With().Str("sessionID", sessionID).Logger() | ||
| defer func() { | ||
| if err := p.config.SessionLogger.Close(); err != nil { | ||
| l.Error().Err(err).Msg("Failed to close session logger") | ||
| } | ||
| }() | ||
|
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| l.Info(). | ||
| Str("targetAddr", p.config.TargetAddr). | ||
| Str("protocol", p.config.Protocol). | ||
| Msg("New WebApp connection for PAM session") | ||
|
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| reader := bufio.NewReader(clientConn) | ||
|
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| // Loop to handle multiple HTTP requests on the same keep-alive connection | ||
| for { | ||
| select { | ||
| case <-ctx.Done(): | ||
| l.Info().Msg("Context cancelled, closing WebApp proxy connection") | ||
| return ctx.Err() | ||
| default: | ||
| } | ||
|
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| // Read request in a goroutine so we can cancel it | ||
| reqCh := make(chan *http.Request, 1) | ||
| errCh := make(chan error, 1) | ||
|
|
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| go func() { | ||
| req, err := http.ReadRequest(reader) | ||
| if err != nil { | ||
| errCh <- err | ||
| } else { | ||
| reqCh <- req | ||
| } | ||
| }() | ||
|
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| var req *http.Request | ||
| select { | ||
| case <-ctx.Done(): | ||
| l.Info().Msg("Context cancelled while reading HTTP request") | ||
| return ctx.Err() | ||
| case err := <-errCh: | ||
| if errors.Is(err, io.EOF) { | ||
| l.Info().Msg("Client closed connection") | ||
| return nil | ||
| } | ||
| l.Error().Err(err).Msg("Failed to read HTTP request") | ||
| return fmt.Errorf("failed to read HTTP request: %w", err) | ||
| case req = <-reqCh: | ||
| // Successfully received request | ||
| } | ||
|
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| requestId := uuid.New().String() | ||
| l.Info(). | ||
| Str("url", req.URL.String()). | ||
| Str("method", req.Method). | ||
| Str("reqId", requestId). | ||
| Msg("Received HTTP request from tunnel") | ||
|
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| // Read request body | ||
| reqBody, err := io.ReadAll(req.Body) | ||
| if err != nil { | ||
| l.Error().Err(err).Msg("Failed to read request body") | ||
| writeErrorResponse(clientConn, "failed to read request body") | ||
| continue | ||
| } | ||
| req.Body.Close() | ||
|
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| // Log the request | ||
| if logErr := p.config.SessionLogger.LogHttpEvent(session.HttpEvent{ | ||
| Timestamp: time.Now(), | ||
| RequestId: requestId, | ||
| EventType: session.HttpEventRequest, | ||
| URL: req.URL.String(), | ||
| Method: req.Method, | ||
| Headers: req.Header, | ||
| Body: reqBody, | ||
| }); logErr != nil { | ||
| l.Error().Err(logErr).Msg("Failed to log HTTP request event") | ||
| } | ||
|
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| // Connect to target and forward request | ||
| targetURL := fmt.Sprintf("%s://%s%s", p.config.Protocol, p.config.TargetAddr, req.URL.RequestURI()) | ||
|
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| proxyReq, err := http.NewRequest(req.Method, targetURL, bytes.NewReader(reqBody)) | ||
| if err != nil { | ||
| l.Error().Err(err).Msg("Failed to create proxy request") | ||
| writeErrorResponse(clientConn, "failed to create proxy request") | ||
| continue | ||
| } | ||
| proxyReq.Header = req.Header.Clone() | ||
|
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| transport := &http.Transport{ | ||
| DisableKeepAlives: false, | ||
| MaxIdleConns: 10, | ||
| IdleConnTimeout: 30 * time.Second, | ||
| TLSClientConfig: p.config.TLSConfig, | ||
| } | ||
| client := &http.Client{ | ||
| Transport: transport, | ||
| Timeout: 30 * time.Second, | ||
| // Don't follow redirects — let the client handle them | ||
| CheckRedirect: func(req *http.Request, via []*http.Request) error { | ||
| return http.ErrUseLastResponse | ||
| }, | ||
| } | ||
|
Comment on lines
+132
to
+145
Contributor
There was a problem hiding this comment. HTTP transport and client created per request A new
The transport and client should be created once per proxy instance (e.g., in // In WebAppProxy struct
type WebAppProxy struct {
config WebAppProxyConfig
transport *http.Transport
client *http.Client
}
func NewWebAppProxy(config WebAppProxyConfig) *WebAppProxy {
transport := &http.Transport{
DisableKeepAlives: false,
MaxIdleConns: 10,
IdleConnTimeout: 30 * time.Second,
TLSClientConfig: config.TLSConfig,
}
client := &http.Client{
Transport: transport,
Timeout: 30 * time.Second,
CheckRedirect: func(req *http.Request, via []*http.Request) error {
return http.ErrUseLastResponse
},
}
return &WebAppProxy{config: config, transport: transport, client: client}
} |
||
|
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| resp, err := client.Do(proxyReq) | ||
| if err != nil { | ||
| l.Error().Err(err).Msg("Failed to forward request to target") | ||
| writeErrorResponse(clientConn, fmt.Sprintf("failed to reach target: %s", err.Error())) | ||
| continue | ||
| } | ||
|
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| // Tee the body for logging | ||
| var bodyCopy bytes.Buffer | ||
| resp.Body = struct { | ||
| io.ReadCloser | ||
| }{ | ||
| ReadCloser: io.NopCloser(io.TeeReader(resp.Body, &bodyCopy)), | ||
| } | ||
|
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| // Write response back to tunnel client | ||
| resp.Header.Del("Connection") | ||
| if err := resp.Write(clientConn); err != nil { | ||
| if errors.Is(err, io.EOF) { | ||
| l.Info().Msg("Client closed connection during response write") | ||
| } else { | ||
| l.Error().Err(err).Msg("Failed to write response to connection") | ||
| } | ||
| resp.Body.Close() | ||
| return fmt.Errorf("failed to write response: %w", err) | ||
| } | ||
| resp.Body.Close() | ||
|
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| // Log the response | ||
| if logErr := p.config.SessionLogger.LogHttpEvent(session.HttpEvent{ | ||
| Timestamp: time.Now(), | ||
| RequestId: requestId, | ||
| EventType: session.HttpEventResponse, | ||
| Status: resp.Status, | ||
| Headers: resp.Header, | ||
| Body: bodyCopy.Bytes(), | ||
| }); logErr != nil { | ||
| l.Error().Err(logErr).Msg("Failed to log HTTP response event") | ||
| } | ||
|
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| l.Info(). | ||
| Str("reqId", requestId). | ||
| Str("status", resp.Status). | ||
| Msg("Forwarded response back to tunnel") | ||
| } | ||
| } | ||
|
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| func writeErrorResponse(conn net.Conn, message string) { | ||
| errResp := fmt.Sprintf( | ||
| "HTTP/1.1 502 Bad Gateway\r\nContent-Type: application/json\r\n\r\n{\"message\": \"gateway: %s\"}", | ||
| message, | ||
| ) | ||
| conn.Write([]byte(errResp)) | ||
| } | ||
|
Comment on lines
+194
to
+200
Contributor
There was a problem hiding this comment. JSON injection in error response body The For example, the call at line 150: writeErrorResponse(clientConn, fmt.Sprintf("failed to reach target: %s", err.Error()))could produce: Use func writeErrorResponse(conn net.Conn, message string) {
type errBody struct {
Message string `json:"message"`
}
body, _ := json.Marshal(errBody{Message: "gateway: " + message})
errResp := fmt.Sprintf(
"HTTP/1.1 502 Bad Gateway\r\nContent-Type: application/json\r\nContent-Length: %d\r\n\r\n%s",
len(body), body,
)
conn.Write([]byte(errResp))
} |
||
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No request body size limit (potential DoS)
io.ReadAll(req.Body)reads the entire request body into memory with no upper bound. A malicious or misbehaving client could send an extremely large body (e.g., a multi-GB upload) causing memory exhaustion on the gateway process. Consider wrapping the body withhttp.MaxBytesReaderbefore reading:Note:
http.MaxBytesReaderrequires anhttp.ResponseWriteras its first argument; if that doesn't fit here, you can instead useio.LimitReader: