浏览器存储密码离线解密

一、任务目标

从Windows取证镜像中提取浏览器保存的网站 www.xxxxxxxx.top 账号 lulan 的密码。

二、最终结果

浏览器 网站 用户名 密码
Chrome https://www.xxxxxxxx.top/ admin111 98uhy675e
Edge https://www.xxxxxxxx.top/ lulan a8sa9syai
Chrome https://www.xxxxxxxx.top/ admin998 admin998156
Edge https://www.xxxxxxxx.top/ admin998 admin998156

**答案：账号 lulan 的密码为 a8sa9syai**（保存在Edge浏览器中）

三、加密原理

Chrome/Edge（v80+）均基于Chromium，密码加密采用两层结构：

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      Windows用户密码
           │
           ▼
┌─────────────────────┐
│  DPAPI Master Key   │  ← 存储在 Protect\{SID}\{GUID}
│  (用户密码派生解密)   │
└─────────┬───────────┘
          │
          ▼
┌─────────────────────┐
│  浏览器 AES-256 Key │  ← 存储在 Local State（DPAPI加密）
└─────────┬───────────┘
          │
          ▼
┌─────────────────────┐
│   AES-256-GCM 解密  │  ← 密码密文存储在 Login Data
└─────────┬───────────┘
          │
          ▼
      密码明文

密码密文格式（Login Data中的password_value字段）：

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[v10] [nonce: 12字节] [ciphertext] [tag: 16字节]
 3字节   AES-GCM随机数    密文        认证标签

四、所需取证文件

从镜像中导出以下文件（用户名 chenchen）：

Chrome

文件 镜像路径
Login Data C:\Users\chenchen\AppData\Local\Google\Chrome\User Data\Default\Login Data
Local State C:\Users\chenchen\AppData\Local\Google\Chrome\User Data\Local State

Edge

文件 镜像路径
Login Data C:\Users\chenchen\AppData\Local\Microsoft\Edge\User Data\Default\Login Data
Local State C:\Users\chenchen\AppData\Local\Microsoft\Edge\User Data\Local State

DPAPI（Chrome和Edge共用）

文件 镜像路径
Master Key C:\Users\chenchen\AppData\Roaming\Microsoft\Protect\S-1-5-21-17485621-1970499508-3307361946-1001\ad9b27cd-405e-44c5-9eb5-67e1f7c89def

Master Key的GUID可从Local State中的DPAPI Blob解析得到。

五、解密步骤详解

步骤1：读取Login Data查看加密记录

Login Data是SQLite数据库，查询logins表：

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import sqlite3

conn = sqlite3.connect('Login Data')
cursor = conn.cursor()
cursor.execute('SELECT origin_url, username_value, password_value FROM logins')
for url, username, pwd in cursor.fetchall():
    print(f'{url} | {username} | {pwd.hex()}')

输出（以Edge为例）：

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https://www.xxxxxxxx.top/ | lulan | 763130...（加密数据）

密码字段以 763130（ASCII “v10”）开头，确认为Chrome v80+加密格式。

步骤2：从Local State提取DPAPI加密的浏览器密钥

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import json, base64

with open('Local State', 'r', encoding='utf-8') as f:
    local_state = json.load(f)

encrypted_key = base64.b64decode(local_state['os_crypt']['encrypted_key'])
dpapi_blob = encrypted_key[5:]  # 去掉 "DPAPI" 前缀（5字节）

解析DPAPI Blob可得到所需Master Key的GUID：AD9B27CD-405E-44C5-9EB5-67E1F7C89DEF

步骤3：使用Windows密码解密DPAPI Master Key

DPAPI密钥派生过程：

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from hashlib import sha1
from Cryptodome.Hash import HMAC, SHA1

password = 'qwer123'
user_sid = 'S-1-5-21-17485621-1970499508-3307361946-1001'

# 1) 计算密码的SHA1
sha1_hash = sha1(password.encode('utf-16le')).digest()

# 2) HMAC-SHA1(SHA1(password), UTF16LE(SID + '\0')) 派生预密钥
prekey = HMAC.new(sha1_hash, (user_sid + '\0').encode('utf-16le'), SHA1).digest()

用预密钥解密Master Key文件：

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from impacket.dpapi import MasterKeyFile, MasterKey

with open('ad9b27cd-405e-44c5-9eb5-67e1f7c89def', 'rb') as f:
    mk_data = f.read()

mk_file = MasterKeyFile(mk_data)
mk = MasterKey(mk_data[len(mk_file.getData()):])

# impacket内部执行 PBKDF2-SHA512(prekey, salt, 8000次迭代)
# 派生AES-256密钥解密Master Key，并通过HMAC-SHA512验证完整性
master_key = mk.decrypt(prekey)

解密得到64字节的Master Key：

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9555714bc67d3988852b2bb41dfec14d3d8cc9a2c7f0c577
0814c315ff391fc82405b46a190ce423e1b631e2848f30bf
bc15b3133550629c11f54ca6aa86dfe4

步骤4：解密浏览器AES Key

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from impacket.dpapi import DPAPI_BLOB

blob = DPAPI_BLOB(dpapi_blob)
browser_key = blob.decrypt(master_key)
浏览器 AES-256 Key
Chrome 18b27bd82bfa6b739bb6f2149135dac512585599be00028f496ba91b81c407c2
Edge 717a8873ffa72c532e7378c3932ffa5ac0ee1b367e1a42a972b7647101ca44a9

步骤5：AES-256-GCM解密密码

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from Cryptodome.Cipher import AES

encrypted_pwd = ...  # 从Login Data读取的password_value

nonce = encrypted_pwd[3:15]        # 跳过"v10"，取12字节nonce
ciphertext = encrypted_pwd[15:-16] # 密文
tag = encrypted_pwd[-16:]          # 认证标签

cipher = AES.new(browser_key, AES.MODE_GCM, nonce=nonce)
password = cipher.decrypt_and_verify(ciphertext, tag).decode('utf-8')

六、完整解密脚本

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#!/usr/bin/env python3
"""浏览器密码离线解密工具（Chrome/Edge）"""

import json, base64, sqlite3
from hashlib import sha1
from Cryptodome.Hash import HMAC, SHA1
from Cryptodome.Cipher import AES
from impacket.dpapi import MasterKeyFile, MasterKey, DPAPI_BLOB

def decrypt_browser_passwords(login_data_path, local_state_path,
                               masterkey_path, user_sid, win_password):
    # === 阶段1：解密DPAPI Master Key ===
    sha1_hash = sha1(win_password.encode('utf-16le')).digest()
    prekey = HMAC.new(sha1_hash, (user_sid + '\0').encode('utf-16le'), SHA1).digest()

    with open(masterkey_path, 'rb') as f:
        mk_data = f.read()
    mk_file = MasterKeyFile(mk_data)
    mk = MasterKey(mk_data[len(mk_file.getData()):])
    master_key = mk.decrypt(prekey)
    if not master_key:
        raise Exception("Master Key解密失败，Windows密码可能错误")

    # === 阶段2：解密浏览器AES Key ===
    with open(local_state_path, 'r', encoding='utf-8') as f:
        local_state = json.load(f)
    encrypted_key = base64.b64decode(local_state['os_crypt']['encrypted_key'])
    blob = DPAPI_BLOB(encrypted_key[5:])
    browser_key = blob.decrypt(master_key)

    # === 阶段3：解密所有密码 ===
    conn = sqlite3.connect(login_data_path)
    cursor = conn.cursor()
    cursor.execute('SELECT origin_url, username_value, password_value FROM logins')

    results = []
    for url, username, enc_pwd in cursor.fetchall():
        if enc_pwd and len(enc_pwd) > 3 and enc_pwd[:3] == b'v10':
            nonce = enc_pwd[3:15]
            ct_tag = enc_pwd[15:]
            cipher = AES.new(browser_key, AES.MODE_GCM, nonce=nonce)
            pwd = cipher.decrypt_and_verify(ct_tag[:-16], ct_tag[-16:]).decode('utf-8')
            results.append((url, username, pwd))
    conn.close()
    return results


if __name__ == '__main__':
    SID = 'S-1-5-21-17485621-1970499508-3307361946-1001'
    WIN_PWD = 'qwer123'
    MK_PATH = 'ad9b27cd-405e-44c5-9eb5-67e1f7c89def'

    # Chrome
    print("=== Chrome ===")
    for url, user, pwd in decrypt_browser_passwords(
        'Chrome_Login Data', 'Chrome_Local State', MK_PATH, SID, WIN_PWD):
        print(f'{url} | {user} | {pwd}')

    # Edge
    print("\n=== Edge ===")
    for url, user, pwd in decrypt_browser_passwords(
        'Edge_Login Data', 'Edge_Local State', MK_PATH, SID, WIN_PWD):
        print(f'{url} | {user} | {pwd}')

七、总结

  1. Chrome/Edge共用DPAPI体系：同一用户下Chrome和Edge使用相同的DPAPI Master Key，但各自有独立的AES Key
  2. Master Key GUID定位：DPAPI Blob内嵌了所需Master Key的GUID，对应 Protect\{SID}\ 下的文件名
  3. 密钥派生链：Windows密码 → SHA1 → HMAC-SHA1(+SID) → PBKDF2-SHA512(+salt, 8000轮) → 解密Master Key
  4. 离线解密必要条件：Windows用户密码 + Master Key文件 + 用户SID + Login Data + Local State
  5. 依赖库：impacket（DPAPI解析）、pycryptodome（AES-GCM解密）