Snipaste截图元数据区块链存证：为电子证据提供法律效力的时间戳与完整性验证

import hashlib
import requests
import json
from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler

class SnipasteHandler(FileSystemEventHandler):
    def on_created(self, event):
        if event.is_directory or not event.src_path.endswith('.png'):
            return
        # 1. 计算截图文件哈希
        with open(event.src_path, 'rb') as f:
            file_hash = hashlib.sha256(f.read()).hexdigest()
        # 2. 提取或准备元数据（可从文件名、系统环境等获取）
        metadata = {
            "file_name": os.path.basename(event.src_path),
            "hash": file_hash,
            "local_time": time.ctime(os.path.getctime(event.src_path)),
            "operator": os.getlogin(),
            # ... 其他自定义字段
        }
        # 3. 调用区块链存证平台API
        payload = {
            "bizId": "您的业务ID",
            "hash": file_hash,
            "metadata": json.dumps(metadata)
        }
        # 这里以调用一个假设的存证平台API为例
        response = requests.post("https://api.blockchain-notary.com/v1/evidences", json=payload, headers={"Authorization": "Bearer YOUR_API_KEY"})
        if response.status_code == 200:
            tx_hash = response.json()["txHash"]
            # 4. 将存证凭证（txHash）写回文件元数据或单独数据库
            # 使用exiftool等工具将txHash写入截图文件的EXIF注释字段
            os.system(f'exiftool -Comment="{tx_hash}" "{event.src_path}"')
            print(f"文件 {event.src_path} 存证成功，交易哈希: {tx_hash}")
        else:
            print("存证失败")

if __name__ == "__main__":
    path_to_watch = "C:/Snipaste/Evidence"
    event_handler = SnipasteHandler()
    observer = Observer()
    observer.schedule(event_handler, path_to_watch, recursive=False)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()