[client,signal,management] Add browser client support (#4415)

client/wasm/internal/rdp/cert_validation.go

@@ -0,0 +1,96 @@
+//go:build js
+
+package rdp
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"syscall/js"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	certValidationTimeout = 60 * time.Second
+)
+
+func (p *RDCleanPathProxy) validateCertificateWithJS(conn *proxyConnection, certChain [][]byte) (bool, error) {
+	if !conn.wsHandlers.Get("onCertificateRequest").Truthy() {
+		return false, fmt.Errorf("certificate validation handler not configured")
+	}
+
+	certInfo := js.Global().Get("Object").New()
+	certInfo.Set("ServerAddr", conn.destination)
+
+	certArray := js.Global().Get("Array").New()
+	for i, certBytes := range certChain {
+		uint8Array := js.Global().Get("Uint8Array").New(len(certBytes))
+		js.CopyBytesToJS(uint8Array, certBytes)
+		certArray.SetIndex(i, uint8Array)
+	}
+	certInfo.Set("ServerCertChain", certArray)
+	if len(certChain) > 0 {
+		cert, err := x509.ParseCertificate(certChain[0])
+		if err == nil {
+			info := js.Global().Get("Object").New()
+			info.Set("subject", cert.Subject.String())
+			info.Set("issuer", cert.Issuer.String())
+			info.Set("validFrom", cert.NotBefore.Format(time.RFC3339))
+			info.Set("validTo", cert.NotAfter.Format(time.RFC3339))
+			info.Set("serialNumber", cert.SerialNumber.String())
+			certInfo.Set("CertificateInfo", info)
+		}
+	}
+
+	promise := conn.wsHandlers.Call("onCertificateRequest", certInfo)
+
+	resultChan := make(chan bool)
+	errorChan := make(chan error)
+
+	promise.Call("then", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+		result := args[0].Bool()
+		resultChan <- result
+		return nil
+	})).Call("catch", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+		errorChan <- fmt.Errorf("certificate validation failed")
+		return nil
+	}))
+
+	select {
+	case result := <-resultChan:
+		if result {
+			log.Info("Certificate accepted by user")
+		} else {
+			log.Info("Certificate rejected by user")
+		}
+		return result, nil
+	case err := <-errorChan:
+		return false, err
+	case <-time.After(certValidationTimeout):
+		return false, fmt.Errorf("certificate validation timeout")
+	}
+}
+
+func (p *RDCleanPathProxy) getTLSConfigWithValidation(conn *proxyConnection) *tls.Config {
+	return &tls.Config{
+		InsecureSkipVerify: true, // We'll validate manually after handshake
+		VerifyConnection: func(cs tls.ConnectionState) error {
+			var certChain [][]byte
+			for _, cert := range cs.PeerCertificates {
+				certChain = append(certChain, cert.Raw)
+			}
+
+			accepted, err := p.validateCertificateWithJS(conn, certChain)
+			if err != nil {
+				return err
+			}
+			if !accepted {
+				return fmt.Errorf("certificate rejected by user")
+			}
+
+			return nil
+		},
+	}
+}