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

client/wasm/internal/ssh/key.go

@@ -0,0 +1,50 @@
+//go:build js
+
+package ssh
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/crypto/ssh"
+)
+
+// parseSSHPrivateKey parses a private key in either SSH or PKCS8 format
+func parseSSHPrivateKey(keyPEM []byte) (ssh.Signer, error) {
+	keyStr := string(keyPEM)
+	if !strings.Contains(keyStr, "-----BEGIN") {
+		keyPEM = []byte("-----BEGIN PRIVATE KEY-----\n" + keyStr + "\n-----END PRIVATE KEY-----")
+	}
+
+	signer, err := ssh.ParsePrivateKey(keyPEM)
+	if err == nil {
+		return signer, nil
+	}
+	logrus.Debugf("SSH: Failed to parse as SSH format: %v", err)
+
+	block, _ := pem.Decode(keyPEM)
+	if block == nil {
+		keyPreview := string(keyPEM)
+		if len(keyPreview) > 100 {
+			keyPreview = keyPreview[:100]
+		}
+		return nil, fmt.Errorf("decode PEM block from key: %s", keyPreview)
+	}
+
+	key, err := x509.ParsePKCS8PrivateKey(block.Bytes)
+	if err != nil {
+		logrus.Debugf("SSH: Failed to parse as PKCS8: %v", err)
+		if rsaKey, err := x509.ParsePKCS1PrivateKey(block.Bytes); err == nil {
+			return ssh.NewSignerFromKey(rsaKey)
+		}
+		if ecKey, err := x509.ParseECPrivateKey(block.Bytes); err == nil {
+			return ssh.NewSignerFromKey(ecKey)
+		}
+		return nil, fmt.Errorf("parse private key: %w", err)
+	}
+
+	return ssh.NewSignerFromKey(key)
+}