Pulse/pkg/licensing/activation_store.go

package licensing

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"os"
	"strings"
)

// ActivationStateFileName is the name of the encrypted activation state file.
const ActivationStateFileName = "activation.enc"

// InstanceFingerprintFileName is the durable installation identity used for
// activation-key installs. It is intentionally separate from activation.enc so
// clearing a license does not make one machine consume another install slot.
const InstanceFingerprintFileName = "instance-fingerprint"

const maxInstanceFingerprintFileSize = 512

// LoadOrCreateInstanceFingerprint returns the stable local installation
// fingerprint, creating it if this config directory has not activated before.
func (p *Persistence) LoadOrCreateInstanceFingerprint() (string, error) {
	fingerprintPath, err := resolvePersistencePath(p.configDir, InstanceFingerprintFileName)
	if err != nil {
		return "", fmt.Errorf("resolve instance fingerprint path: %w", err)
	}

	data, err := readBoundedPersistenceRegularFile(fingerprintPath, maxInstanceFingerprintFileSize)
	if err == nil {
		fingerprint := strings.TrimSpace(string(data))
		if fingerprint == "" {
			return "", fmt.Errorf("instance fingerprint file is empty")
		}
		if err := p.SaveInstanceFingerprint(fingerprint); err != nil {
			return "", fmt.Errorf("secure instance fingerprint file: %w", err)
		}
		return fingerprint, nil
	}
	if !isMissingPersistencePathError(err) {
		return "", fmt.Errorf("read instance fingerprint file: %w", err)
	}

	state, err := p.LoadActivationState()
	if err != nil {
		return "", fmt.Errorf("load activation state for instance fingerprint: %w", err)
	}
	if state != nil {
		fingerprint := strings.TrimSpace(state.InstanceFingerprint)
		if fingerprint != "" {
			if err := p.SaveInstanceFingerprint(fingerprint); err != nil {
				return "", err
			}
			return fingerprint, nil
		}
	}

	fingerprint, err := generateFingerprint()
	if err != nil {
		return "", fmt.Errorf("generate instance fingerprint: %w", err)
	}
	if err := p.SaveInstanceFingerprint(fingerprint); err != nil {
		return "", err
	}
	return fingerprint, nil
}

// SaveInstanceFingerprint persists the stable local installation fingerprint.
func (p *Persistence) SaveInstanceFingerprint(fingerprint string) error {
	fingerprint = strings.TrimSpace(fingerprint)
	if fingerprint == "" {
		return fmt.Errorf("instance fingerprint cannot be empty")
	}
	fingerprintPath, err := resolvePersistencePath(p.configDir, InstanceFingerprintFileName)
	if err != nil {
		return fmt.Errorf("resolve instance fingerprint path: %w", err)
	}
	if err := writeOwnerOnlyPersistenceFileAtomic(fingerprintPath, []byte(fingerprint+"\n")); err != nil {
		return fmt.Errorf("write instance fingerprint file: %w", err)
	}
	return nil
}

// SaveActivationState encrypts and persists the activation state to disk.
func (p *Persistence) SaveActivationState(state *ActivationState) error {
	if state == nil {
		return fmt.Errorf("activation state cannot be nil")
	}

	// Ensure we have a persistent encryption key.
	newKey, err := p.ensurePersistentKey()
	if err != nil {
		return fmt.Errorf("ensure persistent encryption key: %w", err)
	}
	if newKey != "" {
		p.encryptionKey = newKey
	}

	jsonData, err := json.Marshal(state)
	if err != nil {
		return fmt.Errorf("marshal activation state: %w", err)
	}

	encrypted, err := p.encrypt(jsonData)
	if err != nil {
		return fmt.Errorf("encrypt activation state: %w", err)
	}

	configDir, err := normalizePersistenceConfigDir(p.configDir)
	if err != nil {
		return fmt.Errorf("resolve config directory: %w", err)
	}
	if err := ensurePersistenceOwnerOnlyDir(configDir); err != nil {
		return fmt.Errorf("secure config directory: %w", err)
	}

	statePath, err := resolvePersistencePath(configDir, ActivationStateFileName)
	if err != nil {
		return fmt.Errorf("resolve activation state file path: %w", err)
	}
	encoded := base64.StdEncoding.EncodeToString(encrypted)

	if err := writeOwnerOnlyPersistenceFileAtomic(statePath, []byte(encoded)); err != nil {
		return fmt.Errorf("write activation state file: %w", err)
	}

	return nil
}

// LoadActivationState reads and decrypts the activation state from disk.
// Returns nil, nil if no activation state file exists.
func (p *Persistence) LoadActivationState() (*ActivationState, error) {
	statePath, err := resolvePersistencePath(p.configDir, ActivationStateFileName)
	if err != nil {
		return nil, fmt.Errorf("resolve activation state file path: %w", err)
	}

	encoded, err := readBoundedPersistenceRegularFile(statePath, maxLicenseFileSize)
	if err != nil {
		if isMissingPersistencePathError(err) {
			return nil, nil // No activation state saved
		}
		return nil, fmt.Errorf("read activation state file: %w", err)
	}

	var state ActivationState
	migratedPlaintext := false

	if encrypted, err := base64.StdEncoding.DecodeString(string(encoded)); err == nil {
		decrypted, decErr := p.decryptWithCompatibleKeys(encrypted)
		if decErr != nil {
			return nil, fmt.Errorf("decrypt activation state: %w", decErr)
		}
		if err := json.Unmarshal(decrypted, &state); err != nil {
			return nil, fmt.Errorf("unmarshal activation state: %w", err)
		}
	} else {
		// Legacy plaintext activation.enc is migration-only input.
		if err := json.Unmarshal(encoded, &state); err != nil {
			return nil, fmt.Errorf("decode activation state file: %w", err)
		}
		migratedPlaintext = true
	}

	if migratedPlaintext {
		if err := p.SaveActivationState(&state); err != nil {
			return nil, fmt.Errorf("rewrite plaintext activation state file: %w", err)
		}
	}

	return &state, nil
}

// ClearActivationState removes the activation state file from disk.
func (p *Persistence) ClearActivationState() error {
	statePath, err := resolvePersistencePath(p.configDir, ActivationStateFileName)
	if err != nil {
		return fmt.Errorf("resolve activation state file path: %w", err)
	}
	err = os.Remove(statePath)
	if err != nil && !os.IsNotExist(err) {
		return fmt.Errorf("delete activation state file: %w", err)
	}
	return nil
}

// ActivationStateExists checks if an activation state file exists on disk.
func (p *Persistence) ActivationStateExists() bool {
	statePath, err := resolvePersistencePath(p.configDir, ActivationStateFileName)
	if err != nil {
		return false
	}
	info, err := os.Lstat(statePath)
	if err != nil {
		return false
	}
	if info.Mode()&os.ModeSymlink != 0 {
		return false
	}
	return info.Mode().IsRegular()
}