修复了一些已知问题

backend/internal/api/apikey.go

@@ -2,10 +2,10 @@ package api
 
 import (
 	"crypto/rand"
-	"crypto/sha256"
 	"crypto/subtle"
 	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"net"
 	"net/http"
 	"strconv"
@@ -13,6 +13,8 @@ import (
 	"time"
 
 	"clicd/internal/config"
+
+	"golang.org/x/crypto/argon2"
 )
 
 type ApiKey struct {
@@ -79,14 +81,23 @@ func createApiKey(w http.ResponseWriter, r *http.Request) {
 
 	// Generate key: clicd_sk_ + 32 hex chars
 	rawBytes := make([]byte, 16)
-	rand.Read(rawBytes)
+	if _, err := rand.Read(rawBytes); err != nil {
+		jsonResponse(w, http.StatusInternalServerError, APIResponse{Success: false, Message: "Failed to generate API key"})
+		return
+	}
 	rawKey := "clicd_sk_" + hex.EncodeToString(rawBytes)
 
+	keyHash, err := hashAPIKey(rawKey)
+	if err != nil {
+		jsonResponse(w, http.StatusInternalServerError, APIResponse{Success: false, Message: "Failed to store API key"})
+		return
+	}
+
 	now := time.Now().Format("2006-01-02 15:04:05")
 	key := config.ApiKeyConfig{
 		ID:          generateShortID(),
 		Name:        req.Name,
-		KeyHash:     hashKey(rawKey),
+		KeyHash:     keyHash,
 		Prefix:      rawKey[:13] + "...",
 		IPWhitelist: strings.TrimSpace(req.IPWhitelist),
 		CreatedAt:   now,
@@ -114,10 +125,59 @@ func generateShortID() string {
 	return hex.EncodeToString(b)
 }
 
-// hashKey creates a simple hash for storage (not reversible)
-func hashKey(key string) string {
-	sum := sha256.Sum256([]byte(key))
-	return hex.EncodeToString(sum[:])
+const (
+	apiKeyHashPrefix     = "argon2id"
+	apiKeyHashTime       = uint32(3)
+	apiKeyHashMemory     = uint32(64 * 1024)
+	apiKeyHashThreads    = uint8(1)
+	apiKeyHashSaltLength = 16
+	apiKeyHashKeyLength  = uint32(32)
+)
+
+// hashAPIKey stores API keys using a salted slow password-hash style function.
+func hashAPIKey(key string) (string, error) {
+	salt := make([]byte, apiKeyHashSaltLength)
+	if _, err := rand.Read(salt); err != nil {
+		return "", err
+	}
+	return hashAPIKeyWithSalt(key, salt), nil
+}
+
+func hashAPIKeyWithSalt(key string, salt []byte) string {
+	digest := argon2.IDKey([]byte(key), salt, apiKeyHashTime, apiKeyHashMemory, apiKeyHashThreads, apiKeyHashKeyLength)
+	return fmt.Sprintf("%s$v=19$m=%d,t=%d,p=%d$%s$%s",
+		apiKeyHashPrefix,
+		apiKeyHashMemory,
+		apiKeyHashTime,
+		apiKeyHashThreads,
+		hex.EncodeToString(salt),
+		hex.EncodeToString(digest),
+	)
+}
+
+func verifyAPIKeyHash(rawKey, storedHash string) bool {
+	parts := strings.Split(storedHash, "$")
+	if len(parts) != 5 || parts[0] != apiKeyHashPrefix || parts[1] != "v=19" {
+		return false
+	}
+	var memory, iterations uint32
+	var threads uint8
+	if _, err := fmt.Sscanf(parts[2], "m=%d,t=%d,p=%d", &memory, &iterations, &threads); err != nil {
+		return false
+	}
+	if memory != apiKeyHashMemory || iterations != apiKeyHashTime || threads != apiKeyHashThreads {
+		return false
+	}
+	salt, err := hex.DecodeString(parts[3])
+	if err != nil || len(salt) == 0 {
+		return false
+	}
+	expected, err := hex.DecodeString(parts[4])
+	if err != nil || len(expected) == 0 {
+		return false
+	}
+	digest := argon2.IDKey([]byte(rawKey), salt, iterations, memory, threads, uint32(len(expected)))
+	return subtle.ConstantTimeCompare(digest, expected) == 1
 }
 
 func legacyHashKey(key string) string {
@@ -128,20 +188,36 @@ func legacyHashKey(key string) string {
 	return hex.EncodeToString(b)
 }
 
-// validateApiKey checks if the given key is valid and IP is allowed
-func validateApiKey(rawKey, clientIP string) bool {
-	hashed := hashKey(rawKey)
+func matchApiKey(rawKey string) (idx int, needsRehash bool) {
 	legacyHashed := legacyHashKey(rawKey)
-	for _, k := range config.AppConfig.ApiKeys {
-		if subtle.ConstantTimeCompare([]byte(k.KeyHash), []byte(hashed)) == 1 ||
-			subtle.ConstantTimeCompare([]byte(k.KeyHash), []byte(legacyHashed)) == 1 {
-			if k.IPWhitelist == "" {
-				return true
-			}
-			return isIPAllowed(clientIP, k.IPWhitelist)
+	for i, k := range config.AppConfig.ApiKeys {
+		if verifyAPIKeyHash(rawKey, k.KeyHash) {
+			return i, false
+		}
+		if subtle.ConstantTimeCompare([]byte(k.KeyHash), []byte(legacyHashed)) == 1 {
+			return i, true
 		}
 	}
-	return false
+	return -1, false
+}
+
+// validateApiKey checks if the given key is valid and IP is allowed.
+func validateApiKey(rawKey, clientIP string) bool {
+	idx, needsRehash := matchApiKey(rawKey)
+	if idx < 0 {
+		return false
+	}
+	k := config.AppConfig.ApiKeys[idx]
+	if k.IPWhitelist != "" && !isIPAllowed(clientIP, k.IPWhitelist) {
+		return false
+	}
+	if needsRehash {
+		if newHash, err := hashAPIKey(rawKey); err == nil {
+			config.AppConfig.ApiKeys[idx].KeyHash = newHash
+			config.SaveConfig()
+		}
+	}
+	return true
 }
 
 func apiKeyFromRequest(r *http.Request) string {
@@ -228,17 +304,14 @@ func ip4ToUint32(ip net.IP) uint32 {
 	return uint32(ip[0])<<24 | uint32(ip[1])<<16 | uint32(ip[2])<<8 | uint32(ip[3])
 }
 
-// updateApiKeyLastUsed marks the key as recently used
+// updateApiKeyLastUsed marks the key as recently used.
 func updateApiKeyLastUsed(rawKey string) {
-	hashed := hashKey(rawKey)
-	now := time.Now().Format("2006-01-02 15:04:05")
-	for i := range config.AppConfig.ApiKeys {
-		if config.AppConfig.ApiKeys[i].KeyHash == hashed {
-			config.AppConfig.ApiKeys[i].LastUsed = now
-			config.SaveConfig()
-			return
-		}
+	idx, _ := matchApiKey(rawKey)
+	if idx < 0 {
+		return
 	}
+	config.AppConfig.ApiKeys[idx].LastUsed = time.Now().Format("2006-01-02 15:04:05")
+	config.SaveConfig()
 }
 
 // ApiKeyMiddleware authenticates requests via X-API-Key header or Authorization bearer.

backend/internal/api/apikey_test.go

@@ -0,0 +1,102 @@
+package api
+
+import (
+	"strings"
+	"testing"
+
+	"clicd/internal/config"
+)
+
+func TestHashAPIKeyUsesSaltedArgon2idHash(t *testing.T) {
+	raw := "clicd_sk_0123456789abcdef0123456789abcdef"
+
+	h1, err := hashAPIKey(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	h2, err := hashAPIKey(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if h1 == h2 {
+		t.Fatal("expected salted hashes to differ")
+	}
+	if !strings.HasPrefix(h1, apiKeyHashPrefix+"$") || !strings.HasPrefix(h2, apiKeyHashPrefix+"$") {
+		t.Fatalf("expected argon2id hashes, got %q and %q", h1, h2)
+	}
+	if !verifyAPIKeyHash(raw, h1) || !verifyAPIKeyHash(raw, h2) {
+		t.Fatal("argon2id hashes did not verify")
+	}
+	if verifyAPIKeyHash(raw+"x", h1) {
+		t.Fatal("argon2id hash verified wrong key")
+	}
+}
+
+func TestValidateApiKeyAllowsArgon2idAndUpdatesLastUsed(t *testing.T) {
+	raw := "clicd_sk_0123456789abcdef0123456789abcdef"
+	hash, err := hashAPIKey(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	config.AppConfig = &config.ClicdConfig{
+		ApiKeys: []config.ApiKeyConfig{{
+			ID:      "key1",
+			Name:    "test",
+			KeyHash: hash,
+		}},
+	}
+
+	if !validateApiKey(raw, "127.0.0.1") {
+		t.Fatal("validateApiKey rejected valid argon2id key")
+	}
+	updateApiKeyLastUsed(raw)
+	if config.AppConfig.ApiKeys[0].LastUsed == "" {
+		t.Fatal("LastUsed was not updated")
+	}
+}
+
+func TestValidateApiKeyMigratesLegacyHash(t *testing.T) {
+	raw := "clicd_sk_0123456789abcdef0123456789abcdef"
+	config.AppConfig = &config.ClicdConfig{
+		ApiKeys: []config.ApiKeyConfig{{
+			ID:      "legacy",
+			Name:    "legacy",
+			KeyHash: legacyHashKey(raw),
+		}},
+	}
+
+	if !validateApiKey(raw, "127.0.0.1") {
+		t.Fatal("validateApiKey rejected valid legacy key")
+	}
+	migrated := config.AppConfig.ApiKeys[0].KeyHash
+	if migrated == legacyHashKey(raw) {
+		t.Fatal("legacy key hash was not migrated")
+	}
+	if !verifyAPIKeyHash(raw, migrated) {
+		t.Fatal("migrated key hash does not verify")
+	}
+}
+
+func TestValidateApiKeyAppliesIPWhitelist(t *testing.T) {
+	raw := "clicd_sk_0123456789abcdef0123456789abcdef"
+	hash, err := hashAPIKey(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	config.AppConfig = &config.ClicdConfig{
+		ApiKeys: []config.ApiKeyConfig{{
+			ID:          "key1",
+			Name:        "test",
+			KeyHash:     hash,
+			IPWhitelist: "192.0.2.10",
+		}},
+	}
+
+	if validateApiKey(raw, "198.51.100.10") {
+		t.Fatal("validateApiKey allowed disallowed IP")
+	}
+	if !validateApiKey(raw, "192.0.2.10") {
+		t.Fatal("validateApiKey rejected allowed IP")
+	}
+}

backend/internal/cli/cli.go

@@ -20,6 +20,11 @@ import (
 
 var manager = lxc.NewManager()
 
+const (
+	clicdBackupDir     = "/root/clicd-backups"
+	clicdNewBinaryPath = "/usr/local/bin/clicd.new"
+)
+
 // Run starts the CLI interface.
 func Run() {
 	reader := bufio.NewReader(os.Stdin)
@@ -198,11 +203,18 @@ func cliCreateContainer(reader *bufio.Reader) {
 	container := config.FindContainerByName(name)
 	fmt.Printf("容器 %s 创建成功\n", name)
 	if container != nil {
-		fmt.Printf("SSH: root / %s, port %d -> 22\n", container.SSHPassword, container.SSHPort)
+		fmt.Print(formatSSHAccess(container.SSHPort))
 	}
 	restartWebPanelForConfigChange()
 }
 
+func formatSSHAccess(sshPort int) string {
+	if sshPort <= 0 {
+		return "SSH: root, 端口未分配。密码已保存，请在 Web 面板中查看或重置。\n"
+	}
+	return fmt.Sprintf("SSH: root, port %d -> 22。密码已保存，请在 Web 面板中查看或重置。\n", sshPort)
+}
+
 func cliStartContainer(reader *bufio.Reader) {
 	id, name := selectContainer(reader, "开机")
 	if id == 0 {
@@ -532,13 +544,14 @@ func upgradeFromReleaseAsset(assetURL, latest string) error {
 		return err
 	}
 
-	backupDir := "/root/clicd-backups"
+	backupDir := clicdBackupDir
 	if err := os.MkdirAll(backupDir, 0700); err != nil {
 		return err
 	}
-	backupPath := filepath.Join(backupDir, fmt.Sprintf("clicd.%s.%s", strings.TrimPrefix(latest, "v"), time.Now().Format("20060102-150405")))
+	backupName := fmt.Sprintf("clicd.%s.%s", safeReleaseBackupComponent(latest), time.Now().Format("20060102-150405"))
 	if _, err := os.Stat("/usr/local/bin/clicd"); err == nil {
-		if err := copyFile("/usr/local/bin/clicd", backupPath, 0755); err != nil {
+		backupPath, err := copyFileToBackup("/usr/local/bin/clicd", backupName, 0755)
+		if err != nil {
 			return fmt.Errorf("备份旧二进制失败: %w", err)
 		}
 		fmt.Printf("旧版本已备份: %s\n", backupPath)
@@ -548,8 +561,8 @@ func upgradeFromReleaseAsset(assetURL, latest string) error {
 	if err := stopService("clicd"); err != nil {
 		fmt.Printf("停止 Web 服务失败，继续尝试替换: %v\n", err)
 	}
-	tmpBin := "/usr/local/bin/clicd.new"
-	if err := copyFile(newBinary, tmpBin, 0755); err != nil {
+	tmpBin := clicdNewBinaryPath
+	if err := copyFileToUpgradeTemp(newBinary, 0755); err != nil {
 		return err
 	}
 	if err := os.Rename(tmpBin, "/usr/local/bin/clicd"); err != nil {
@@ -614,25 +627,69 @@ func findFile(root, name string) (string, error) {
 	return found, nil
 }
 
-func copyFile(src, dst string, mode os.FileMode) error {
+func copyFileToBackup(src, fileName string, mode os.FileMode) (string, error) {
+	if fileName == "" || strings.Contains(fileName, "/") || strings.Contains(fileName, "\\") || strings.Contains(fileName, "..") {
+		return "", fmt.Errorf("unsafe backup file name: %s", fileName)
+	}
+	dst := filepath.Join(clicdBackupDir, fileName)
+	out, err := os.OpenFile(dst, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, mode)
+	if err != nil {
+		return "", err
+	}
+	if err := copyIntoOpenFile(src, out, mode); err != nil {
+		return "", err
+	}
+	return dst, nil
+}
+
+func copyFileToUpgradeTemp(src string, mode os.FileMode) error {
+	out, err := os.OpenFile(clicdNewBinaryPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, mode)
+	if err != nil {
+		return err
+	}
+	return copyIntoOpenFile(src, out, mode)
+}
+
+func copyIntoOpenFile(src string, out *os.File, mode os.FileMode) error {
 	in, err := os.Open(src)
 	if err != nil {
+		out.Close()
 		return err
 	}
 	defer in.Close()
 
-	out, err := os.OpenFile(dst, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, mode)
-	if err != nil {
+	if _, err := io.Copy(out, in); err != nil {
+		out.Close()
 		return err
 	}
-	if _, err := io.Copy(out, in); err != nil {
+	if err := out.Chmod(mode); err != nil {
 		out.Close()
 		return err
 	}
 	if err := out.Close(); err != nil {
 		return err
 	}
-	return os.Chmod(dst, mode)
+	return nil
+}
+
+func safeReleaseBackupComponent(tag string) string {
+	tag = strings.TrimPrefix(strings.TrimSpace(tag), "v")
+	var b strings.Builder
+	for _, r := range tag {
+		if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '.' || r == '_' || r == '-' {
+			b.WriteRune(r)
+			continue
+		}
+		b.WriteByte('_')
+	}
+	component := strings.Trim(b.String(), "._-")
+	if component == "" {
+		return "unknown"
+	}
+	if len(component) > 64 {
+		return component[:64]
+	}
+	return component
 }
 
 func sameVersion(current, latest string) bool {

backend/internal/cli/cli_test.go

@@ -0,0 +1,54 @@
+package cli
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestSafeReleaseBackupComponent(t *testing.T) {
+	tests := map[string]string{
+		"v1.2.3":              "1.2.3",
+		" release/candidate ": "release_candidate",
+		"../../etc/passwd":    "etc_passwd",
+		"":                    "unknown",
+	}
+	for input, want := range tests {
+		if got := safeReleaseBackupComponent(input); got != want {
+			t.Fatalf("safeReleaseBackupComponent(%q) = %q, want %q", input, got, want)
+		}
+	}
+}
+
+func TestCopyFileToBackupRejectsUnsafeFileName(t *testing.T) {
+	unsafeNames := []string{
+		"../clicd",
+		"..\\clicd",
+		"subdir/clicd",
+		"",
+	}
+	for _, name := range unsafeNames {
+		if _, err := copyFileToBackup("missing-source", name, 0755); err == nil || !strings.Contains(err.Error(), "unsafe backup file name") {
+			t.Fatalf("copyFileToBackup(%q) error = %v, want unsafe backup file name", name, err)
+		}
+	}
+}
+
+func TestFormatSSHAccessDoesNotExposePassword(t *testing.T) {
+	out := formatSSHAccess(2222)
+	if strings.Contains(out, "/") {
+		t.Fatalf("formatSSHAccess output contains credential separator: %q", out)
+	}
+	if strings.Contains(strings.ToLower(out), "password123") {
+		t.Fatalf("formatSSHAccess output exposed password: %q", out)
+	}
+	if !strings.Contains(out, "2222 -> 22") {
+		t.Fatalf("formatSSHAccess output = %q, want SSH port mapping", out)
+	}
+}
+
+func TestFormatSSHAccessHandlesMissingPort(t *testing.T) {
+	out := formatSSHAccess(0)
+	if !strings.Contains(out, "端口未分配") {
+		t.Fatalf("formatSSHAccess output = %q, want missing port message", out)
+	}
+}

backend/internal/kvm/kvm.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/rand"
+	"crypto/sha256"
 	"encoding/base64"
 	"encoding/binary"
 	"encoding/hex"
@@ -738,10 +739,14 @@ func (m *Manager) ResetSSHPassword(id int, password string) (string, error) {
 	if err := m.EnsureSSH(id); err != nil {
 		return "", err
 	}
+	chpasswdInput, err := chpasswdStdin("root", password)
+	if err != nil {
+		return "", err
+	}
 	client, err := ssh.Dial("tcp", net.JoinHostPort(c.IP, "22"), &ssh.ClientConfig{
 		User:            "root",
 		Auth:            []ssh.AuthMethod{ssh.Password(c.SSHPassword)},
-		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		HostKeyCallback: kvmHostKeyCallback(c),
 		Timeout:         8 * time.Second,
 	})
 	if err != nil {
@@ -753,8 +758,8 @@ func (m *Manager) ResetSSHPassword(id int, password string) (string, error) {
 		return "", err
 	}
 	defer session.Close()
-	cmd := fmt.Sprintf("printf 'root:%s\\n' | chpasswd", shellQuote(password))
-	if output, err := session.CombinedOutput(cmd); err != nil {
+	session.Stdin = bytes.NewReader(chpasswdInput)
+	if output, err := session.CombinedOutput("chpasswd"); err != nil {
 		return "", fmt.Errorf("failed to reset password: %v, output: %s", err, string(output))
 	}
 	c.SSHPassword = password
@@ -2224,7 +2229,7 @@ func (m *Manager) EnsureSSH(id int) error {
 		client, err := ssh.Dial("tcp", net.JoinHostPort(c.IP, "22"), &ssh.ClientConfig{
 			User:            "root",
 			Auth:            []ssh.AuthMethod{ssh.Password(c.SSHPassword)},
-			HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+			HostKeyCallback: kvmHostKeyCallback(c),
 			Timeout:         8 * time.Second,
 		})
 		if err != nil {
@@ -3190,7 +3195,7 @@ func (m *Manager) applyGuestIPv6OverSSH(c *config.Container) error {
 	client, err := ssh.Dial("tcp", net.JoinHostPort(c.IP, "22"), &ssh.ClientConfig{
 		User:            "root",
 		Auth:            []ssh.AuthMethod{ssh.Password(c.SSHPassword)},
-		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		HostKeyCallback: kvmHostKeyCallback(c),
 		Timeout:         8 * time.Second,
 	})
 	if err != nil {
@@ -3377,6 +3382,46 @@ func shellQuote(value string) string {
 	return "'" + strings.ReplaceAll(value, "'", "'\"'\"'") + "'"
 }
 
+func chpasswdStdin(username, password string) ([]byte, error) {
+	if username == "" || strings.ContainsAny(username, ":\n\r") {
+		return nil, fmt.Errorf("invalid chpasswd username")
+	}
+	if strings.ContainsAny(password, "\n\r") {
+		return nil, fmt.Errorf("password cannot contain newlines")
+	}
+	return []byte(username + ":" + password + "\n"), nil
+}
+
+func kvmHostKeyCallback(c *config.Container) ssh.HostKeyCallback {
+	return func(hostname string, remote net.Addr, key ssh.PublicKey) error {
+		return verifyKVMHostKey(c, key, config.SaveConfig)
+	}
+}
+
+func verifyKVMHostKey(c *config.Container, key ssh.PublicKey, save func() error) error {
+	if c == nil {
+		return fmt.Errorf("KVM container is nil")
+	}
+	fingerprint := sshHostKeyFingerprint(key)
+	if c.SSHHostKey != "" && c.SSHHostKey != fingerprint {
+		return fmt.Errorf("KVM SSH host key mismatch")
+	}
+	if c.SSHHostKey == "" {
+		c.SSHHostKey = fingerprint
+		if save != nil {
+			if err := save(); err != nil {
+				return fmt.Errorf("failed to save KVM SSH host key: %v", err)
+			}
+		}
+	}
+	return nil
+}
+
+func sshHostKeyFingerprint(key ssh.PublicKey) string {
+	sum := sha256.Sum256(key.Marshal())
+	return hex.EncodeToString(sum[:])
+}
+
 func allocateDefaultEqualPorts(c *config.Container, count int) []int {
 	if count <= 0 {
 		return nil

backend/internal/kvm/kvm_test.go

@@ -0,0 +1,95 @@
+package kvm
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"reflect"
+	"testing"
+
+	"clicd/internal/config"
+
+	"golang.org/x/crypto/ssh"
+)
+
+func TestChpasswdStdinPreservesShellMetacharacters(t *testing.T) {
+	password := `pa'";$(touch /tmp/pwned); echo #\\word`
+	got, err := chpasswdStdin("root", password)
+	if err != nil {
+		t.Fatalf("chpasswdStdin returned error: %v", err)
+	}
+
+	want := []byte("root:" + password + "\n")
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("chpasswdStdin = %#v, want %#v", got, want)
+	}
+}
+
+func TestChpasswdStdinRejectsNewlines(t *testing.T) {
+	tests := []struct {
+		name     string
+		username string
+		password string
+	}{
+		{name: "username newline", username: "root\nadmin", password: "safe"},
+		{name: "username colon", username: "root:admin", password: "safe"},
+		{name: "password newline", username: "root", password: "safe\nroot:evil"},
+		{name: "password carriage return", username: "root", password: "safe\rroot:evil"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if _, err := chpasswdStdin(tc.username, tc.password); err == nil {
+				t.Fatal("chpasswdStdin returned nil error")
+			}
+		})
+	}
+}
+
+func TestVerifyKVMHostKeyCapturesAndRejectsMismatch(t *testing.T) {
+	key1 := testSSHPublicKey(t)
+	key2 := testSSHPublicKey(t)
+
+	saves := 0
+	c := &config.Container{}
+	save := func() error {
+		saves++
+		return nil
+	}
+
+	if err := verifyKVMHostKey(c, key1, save); err != nil {
+		t.Fatalf("first host key verification returned error: %v", err)
+	}
+	if c.SSHHostKey == "" {
+		t.Fatal("first host key verification did not capture fingerprint")
+	}
+	if c.SSHHostKey != sshHostKeyFingerprint(key1) {
+		t.Fatalf("captured fingerprint = %q, want %q", c.SSHHostKey, sshHostKeyFingerprint(key1))
+	}
+	if saves != 1 {
+		t.Fatalf("save count = %d, want 1", saves)
+	}
+
+	if err := verifyKVMHostKey(c, key1, save); err != nil {
+		t.Fatalf("same host key verification returned error: %v", err)
+	}
+	if saves != 1 {
+		t.Fatalf("save count after same key = %d, want 1", saves)
+	}
+
+	if err := verifyKVMHostKey(c, key2, save); err == nil {
+		t.Fatal("mismatched host key verification returned nil error")
+	}
+}
+
+func testSSHPublicKey(t *testing.T) ssh.PublicKey {
+	t.Helper()
+	_, privateKey, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	signer, err := ssh.NewSignerFromKey(privateKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return signer.PublicKey()
+}

backend/internal/lxc/lxc.go

@@ -402,9 +402,10 @@ func (m *Manager) CreateContainer(cfg ContainerConfig) error {
 
 	// Set root password AFTER shiftRootfsForUnprivileged,
 	// otherwise /etc/shadow ownership breaks and SSHD cannot authenticate.
-	setCmd := m.rootfsCommand(rootfsPath,
-		"sh", "-c", fmt.Sprintf("printf '%%s:%%s\\n' root %s | chpasswd", shellQuote(sshPassword)))
-	setCmd.Run()
+	if err := m.runRootfsCommand(rootfsPath,
+		"sh", "-c", fmt.Sprintf("printf '%%s:%%s\\n' root %s | chpasswd", shellQuote(sshPassword))); err != nil {
+		fmt.Printf("Warning: failed to set root password in %s: %v\n", lxcName, err)
+	}
 
 	fmt.Printf("Container %d (%s) created successfully\n", id, cfg.Name)
 	return nil
@@ -429,7 +430,7 @@ func (m *Manager) preconfigureNetwork(rootfsPath, templateID string) {
 		content := "auto lo\niface lo inet loopback\n\nauto eth0\niface eth0 inet dhcp\n"
 		_ = os.MkdirAll(filepath.Dir(interfaces), 0755)
 		_ = os.WriteFile(interfaces, []byte(content), 0644)
-		_ = exec.Command("chroot", rootfsPath, "rc-update", "add", "networking", "boot").Run()
+		_ = m.runRootfsCommand(rootfsPath, "rc-update", "add", "networking", "boot")
 		return
 	}
 
@@ -451,7 +452,7 @@ method=ignore
 			path := filepath.Join(nmDir, "eth0.nmconnection")
 			_ = os.WriteFile(path, []byte(keyfile), 0600)
 		}
-		_ = exec.Command("chroot", rootfsPath, "systemctl", "enable", "NetworkManager").Run()
+		_ = m.runRootfsCommand(rootfsPath, "systemctl", "enable", "NetworkManager")
 	}
 
 	networkdDir := filepath.Join(rootfsPath, "etc", "systemd", "network")
@@ -466,7 +467,7 @@ IPv6AcceptRA=no
 		_ = os.WriteFile(filepath.Join(networkdDir, "10-eth0.network"), []byte(network), 0644)
 	}
 	if !isRHELFamily {
-		_ = exec.Command("chroot", rootfsPath, "systemctl", "enable", "systemd-networkd").Run()
+		_ = m.runRootfsCommand(rootfsPath, "systemctl", "enable", "systemd-networkd")
 	}
 }
 
@@ -475,7 +476,10 @@ func (m *Manager) preconfigureSSH(rootfsPath, password, templateID string) error
 	_ = templateID
 	ctx, cancel := context.WithTimeout(context.Background(), 180*time.Second)
 	defer cancel()
-	cmd := m.rootfsCommand(rootfsPath, "sh", "-c", sshSetupScript(password, false))
+	cmd, err := m.rootfsCommand(rootfsPath, "sh", "-c", sshSetupScript(password, false))
+	if err != nil {
+		return err
+	}
 	cmd = exec.CommandContext(ctx, cmd.Path, cmd.Args[1:]...)
 	output, err := cmd.CombinedOutput()
 	if ctx.Err() == context.DeadlineExceeded {
@@ -1887,7 +1891,10 @@ func (m *Manager) ResetSSHPassword(id int, password string) (string, error) {
 		if err := m.preconfigureSSH(rootfsPath, newPassword, c.Template); err != nil {
 			return "", fmt.Errorf("failed to configure SSH: %v", err)
 		}
-		cmd := m.rootfsCommand(rootfsPath, "sh", "-c", fmt.Sprintf("printf '%%s:%%s\\n' root %s | chpasswd", shellQuote(newPassword)))
+		cmd, err := m.rootfsCommand(rootfsPath, "sh", "-c", fmt.Sprintf("printf '%%s:%%s\\n' root %s | chpasswd", shellQuote(newPassword)))
+		if err != nil {
+			return "", err
+		}
 		output, err := cmd.CombinedOutput()
 		if err != nil {
 			return "", fmt.Errorf("failed to set password: %v, output: %s", err, string(output))
@@ -1899,22 +1906,70 @@ func (m *Manager) ResetSSHPassword(id int, password string) (string, error) {
 	return newPassword, nil
 }
 
-func (m *Manager) rootfsCommand(rootfsPath string, args ...string) *exec.Cmd {
-	marker := filepath.Join(rootfsPath, ".clicd-unprivileged-shifted")
+func (m *Manager) rootfsCommand(rootfsPath string, args ...string) (*exec.Cmd, error) {
+	cleanRootfsPath, err := m.safeRootfsPath(rootfsPath)
+	if err != nil {
+		return nil, err
+	}
+
+	marker := filepath.Join(cleanRootfsPath, ".clicd-unprivileged-shifted")
 	if _, err := os.Stat(marker); err == nil {
 		uidBase, gidBase, mapErr := unprivilegedIDMap()
 		if mapErr == nil {
 			cmdArgs := []string{
 				"-m", fmt.Sprintf("u:0:%d:65536", uidBase),
 				"-m", fmt.Sprintf("g:0:%d:65536", gidBase),
-				"--", "chroot", rootfsPath,
+				"--", "chroot", "--", cleanRootfsPath,
 			}
 			cmdArgs = append(cmdArgs, args...)
-			return exec.Command("lxc-usernsexec", cmdArgs...)
+			return exec.Command("lxc-usernsexec", cmdArgs...), nil
 		}
 	}
-	cmdArgs := append([]string{rootfsPath}, args...)
-	return exec.Command("chroot", cmdArgs...)
+	cmdArgs := append([]string{"--", cleanRootfsPath}, args...)
+	return exec.Command("chroot", cmdArgs...), nil
+}
+
+func (m *Manager) runRootfsCommand(rootfsPath string, args ...string) error {
+	cmd, err := m.rootfsCommand(rootfsPath, args...)
+	if err != nil {
+		return err
+	}
+	return cmd.Run()
+}
+
+func (m *Manager) safeRootfsPath(rootfsPath string) (string, error) {
+	if rootfsPath == "" {
+		return "", fmt.Errorf("empty rootfs path")
+	}
+	if !filepath.IsAbs(rootfsPath) {
+		return "", fmt.Errorf("rootfs path must be absolute: %s", rootfsPath)
+	}
+
+	cleanRootfsPath := filepath.Clean(rootfsPath)
+	cleanLxcPath, err := filepath.Abs(m.LxcPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve LXC path: %v", err)
+	}
+	cleanLxcPath = filepath.Clean(cleanLxcPath)
+
+	if cleanRootfsPath == cleanLxcPath {
+		return "", fmt.Errorf("refusing LXC base path as rootfs: %s", cleanRootfsPath)
+	}
+	if filepath.Base(cleanRootfsPath) != "rootfs" {
+		return "", fmt.Errorf("refusing non-rootfs path: %s", cleanRootfsPath)
+	}
+	if filepath.Dir(cleanRootfsPath) == cleanLxcPath {
+		return "", fmt.Errorf("refusing rootfs directly under LXC path: %s", cleanRootfsPath)
+	}
+
+	rel, err := filepath.Rel(cleanLxcPath, cleanRootfsPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to validate rootfs path: %v", err)
+	}
+	if rel == "." || rel == ".." || strings.HasPrefix(rel, ".."+string(os.PathSeparator)) || filepath.IsAbs(rel) {
+		return "", fmt.Errorf("refusing unsafe rootfs path: %s", cleanRootfsPath)
+	}
+	return cleanRootfsPath, nil
 }
 
 func (m *Manager) cleanupContainerStorage(lxcName string) error {
@@ -2244,9 +2299,10 @@ func (m *Manager) ReinstallContainer(id int, templateID string) error {
 	if err := m.shiftRootfsForUnprivileged(lxcName); err != nil {
 		return err
 	}
-	setCmd := m.rootfsCommand(rootfsPath,
-		"sh", "-c", fmt.Sprintf("printf '%%s:%%s\\n' root %s | chpasswd", shellQuote(c.SSHPassword)))
-	setCmd.Run()
+	if err := m.runRootfsCommand(rootfsPath,
+		"sh", "-c", fmt.Sprintf("printf '%%s:%%s\\n' root %s | chpasswd", shellQuote(c.SSHPassword))); err != nil {
+		fmt.Printf("Warning: failed to set root password in %s after reinstall: %v\n", lxcName, err)
+	}
 
 	// Update template and keep everything else the same
 	c.Template = templateID

backend/internal/lxc/lxc_test.go

@@ -0,0 +1,83 @@
+package lxc
+
+import (
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestRootfsCommandAddsSeparatorAndPreservesArgs(t *testing.T) {
+	base := t.TempDir()
+	rootfs := filepath.Join(base, "ct-1", "rootfs")
+	if err := os.MkdirAll(rootfs, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	m := &Manager{LxcPath: base}
+	cmd, err := m.rootfsCommand(rootfs, "sh", "-c", "true", "--flag")
+	if err != nil {
+		t.Fatalf("rootfsCommand returned error: %v", err)
+	}
+
+	want := []string{"chroot", "--", rootfs, "sh", "-c", "true", "--flag"}
+	if !reflect.DeepEqual(cmd.Args, want) {
+		t.Fatalf("cmd.Args = %#v, want %#v", cmd.Args, want)
+	}
+}
+
+func TestRootfsCommandAllowsLeadingDashContainerName(t *testing.T) {
+	base := t.TempDir()
+	rootfs := filepath.Join(base, "-ct", "rootfs")
+	if err := os.MkdirAll(rootfs, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	m := &Manager{LxcPath: base}
+	cmd, err := m.rootfsCommand(rootfs, "true")
+	if err != nil {
+		t.Fatalf("rootfsCommand returned error: %v", err)
+	}
+
+	want := []string{"chroot", "--", rootfs, "true"}
+	if !reflect.DeepEqual(cmd.Args, want) {
+		t.Fatalf("cmd.Args = %#v, want %#v", cmd.Args, want)
+	}
+}
+
+func TestRootfsCommandRejectsUnsafeRootfsPaths(t *testing.T) {
+	base := t.TempDir()
+	outside := t.TempDir()
+	m := &Manager{LxcPath: base}
+
+	tests := []struct {
+		name string
+		path string
+	}{
+		{name: "outside base", path: filepath.Join(outside, "ct-1", "rootfs")},
+		{name: "base path", path: base},
+		{name: "not rootfs", path: filepath.Join(base, "ct-1", "not-rootfs")},
+		{name: "rootfs directly under base", path: filepath.Join(base, "rootfs")},
+		{name: "relative rootfs", path: filepath.Join("ct-1", "rootfs")},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if _, err := m.rootfsCommand(tc.path, "true"); err == nil {
+				t.Fatalf("rootfsCommand(%q) returned nil error", tc.path)
+			}
+		})
+	}
+}
+
+func TestSafeRootfsPathRejectsSiblingPrefix(t *testing.T) {
+	parent := t.TempDir()
+	base := filepath.Join(parent, "lxc")
+	siblingRootfs := filepath.Join(parent, "lxc-evil", "ct-1", "rootfs")
+	m := &Manager{LxcPath: base}
+
+	if _, err := m.safeRootfsPath(siblingRootfs); err == nil || !strings.Contains(err.Error(), "unsafe rootfs path") {
+		t.Fatalf("safeRootfsPath returned %v, want unsafe rootfs path error", err)
+	}
+}

backend/internal/server/web/.gitkeep

@@ -0,0 +1 @@
+