x

internal/wechat/key/darwin/v4.go

@@ -0,0 +1,184 @@
+package darwin
+
+import (
+	"bytes"
+	"context"
+	"encoding/hex"
+	"fmt"
+	"runtime"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/sjzar/chatlog/internal/wechat/decrypt"
+	"github.com/sjzar/chatlog/internal/wechat/key/darwin/glance"
+	"github.com/sjzar/chatlog/internal/wechat/model"
+)
+
+const (
+	MaxWorkers = 8
+)
+
+type V4Extractor struct {
+	validator *decrypt.Validator
+}
+
+func NewV4Extractor() *V4Extractor {
+	return &V4Extractor{}
+}
+
+func (e *V4Extractor) Extract(ctx context.Context, proc *model.Process) (string, error) {
+	if proc.Status == model.StatusOffline {
+		return "", fmt.Errorf("WeChat is offline")
+	}
+
+	// Check if SIP is disabled, as it's required for memory reading on macOS
+	if !glance.IsSIPDisabled() {
+		return "", fmt.Errorf("System Integrity Protection (SIP) is enabled, cannot read process memory")
+	}
+
+	if e.validator == nil {
+		return "", fmt.Errorf("validator not set")
+	}
+
+	// Create context to control all goroutines
+	searchCtx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	// Create channels for memory data and results
+	memoryChannel := make(chan []byte, 100)
+	resultChannel := make(chan string, 1)
+
+	// Determine number of worker goroutines
+	workerCount := runtime.NumCPU()
+	if workerCount < 2 {
+		workerCount = 2
+	}
+	if workerCount > MaxWorkers {
+		workerCount = MaxWorkers
+	}
+	logrus.Debug("Starting ", workerCount, " workers for V4 key search")
+
+	// Start consumer goroutines
+	var workerWaitGroup sync.WaitGroup
+	workerWaitGroup.Add(workerCount)
+	for index := 0; index < workerCount; index++ {
+		go func() {
+			defer workerWaitGroup.Done()
+			e.worker(searchCtx, memoryChannel, resultChannel)
+		}()
+	}
+
+	// Start producer goroutine
+	var producerWaitGroup sync.WaitGroup
+	producerWaitGroup.Add(1)
+	go func() {
+		defer producerWaitGroup.Done()
+		defer close(memoryChannel) // Close channel when producer is done
+		err := e.findMemory(searchCtx, uint32(proc.PID), memoryChannel)
+		if err != nil {
+			logrus.Error(err)
+		}
+	}()
+
+	// Wait for producer and consumers to complete
+	go func() {
+		producerWaitGroup.Wait()
+		workerWaitGroup.Wait()
+		close(resultChannel)
+	}()
+
+	// Wait for result
+	select {
+	case <-ctx.Done():
+		return "", ctx.Err()
+	case result, ok := <-resultChannel:
+		if ok && result != "" {
+			return result, nil
+		}
+	}
+
+	return "", fmt.Errorf("no valid key found")
+}
+
+// findMemory searches for memory regions using Glance
+func (e *V4Extractor) findMemory(ctx context.Context, pid uint32, memoryChannel chan<- []byte) error {
+	// Initialize a Glance instance to read process memory
+	g := glance.NewGlance(pid)
+
+	// Read memory data
+	memory, err := g.Read()
+	if err != nil {
+		return fmt.Errorf("failed to read process memory: %w", err)
+	}
+
+	logrus.Debug("Read memory region, size: ", len(memory), " bytes")
+
+	// Send memory data to channel for processing
+	select {
+	case memoryChannel <- memory:
+		logrus.Debug("Sent memory region for analysis")
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+
+	return nil
+}
+
+// worker processes memory regions to find V4 version key
+func (e *V4Extractor) worker(ctx context.Context, memoryChannel <-chan []byte, resultChannel chan<- string) {
+	keyPattern := []byte{0x20, 0x66, 0x74, 0x73, 0x35, 0x28, 0x25, 0x00}
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case memory, ok := <-memoryChannel:
+			if !ok {
+				return
+			}
+
+			index := len(memory)
+
+			for {
+				select {
+				case <-ctx.Done():
+					return // Exit if context cancelled
+				default:
+				}
+
+				// Find pattern from end to beginning
+				index = bytes.LastIndex(memory[:index], keyPattern)
+				if index == -1 {
+					break // No more matches found
+				}
+
+				// Check if we have enough space for the key
+				if index+16+32 > len(memory) {
+					index -= 1
+					continue
+				}
+
+				// Extract the key data, which is 16 bytes after the pattern and 32 bytes long
+				keyOffset := index + 16
+				keyData := memory[keyOffset : keyOffset+32]
+
+				// Validate key against database header
+				if e.validator.Validate(keyData) {
+					select {
+					case resultChannel <- hex.EncodeToString(keyData):
+						logrus.Debug("Valid key found for V4 database")
+						return
+					default:
+					}
+				}
+
+				index -= 1
+			}
+		}
+	}
+}
+
+func (e *V4Extractor) SetValidate(validator *decrypt.Validator) {
+	e.validator = validator
+}