文件现在默认保存到download文件夹

增加发送方提醒，使用Segwit地址

recv/recv.py

@@ -1,9 +1,12 @@
 import base64
 
+from Crypto.Hash import SHA256
+
 from config import config
 from entity.Letter import Letter
-from tool import PriKeyHelper
+from tool import PriKeyHelper, DownloadPathTool
 from tool.asymmetric import RSA
+from tool.hash import Segwit
 from tool.symmetric import SM4
 
 
@@ -15,14 +18,15 @@ def getLetter():
     handleLetter(letter)
     pass
 
-def handleLetter(letter:Letter):
+
+def handleLetter(letter: Letter):
     # 解析信件 确认收信人
     # 获取自身key
     pki = PriKeyHelper.getUserKey()
     if pki[1] != letter.recvPubKey:
         raise Exception("信件不属于自己")
     # 用自己的私钥解密key 获得对称加密秘钥。
-    key = RSA.decrypt_message(base64.b64decode(letter.encryptKey),pki[0])
+    key = RSA.decrypt_message(base64.b64decode(letter.encryptKey), pki[0])
 
     # 根据不同的对称加密算法
     try:
@@ -32,9 +36,9 @@ def handleLetter(letter:Letter):
     # 进行解密fileBase64
     data = b""
     if type == config.EncryptType.SM4_ECB:
-        data = base64.b64decode(SM4.decrypt_ecb(letter.fileBase64,key))
+        data = base64.b64decode(SM4.decrypt_ecb(letter.fileBase64, key))
     elif type == config.EncryptType.SM4_CBC:
-        data = base64.b64decode(SM4.decrypt_cbc_with_iv(letter.fileBase64,key))
+        data = base64.b64decode(SM4.decrypt_cbc_with_iv(letter.fileBase64, key))
     elif type == config.EncryptType.AES_ECB:
         raise NotImplementedError("未实现")
     elif type == config.EncryptType.AES_CBC:
@@ -43,12 +47,17 @@ def handleLetter(letter:Letter):
         raise KeyError("不支持的对称加密算法")
 
     # 用发信人的公钥验签摘要
-    result = RSA.verify_signature(data,letter.sign,letter.senderPubKey)
+    result = RSA.verify_signature(data, letter.sign, letter.senderPubKey)
     if not result:
         raise Exception("签名验证失败，文件不可信")
 
     # 保存文件
-    with open(f"./{letter.fileName}","wb") as f:
+
+    # 默认下载目录
+    download_dir = DownloadPathTool.get_download_directory()
+
+    with open(f"{download_dir}/{letter.fileName}", "wb") as f:
         f.write(data)
-        print(f"签名验证有效，已将文件 {letter.fileName} 保存至当前目录下")
+        print(f"确认收到来自 {Segwit.encodeSegwit(letter.senderPubKey.encode("utf-8"))} 的文件")
-    return
+        print(f"签名验证有效，已将文件 {letter.fileName} 保存至 {download_dir} 下")
+    return

tool/DownloadPathTool.py

@@ -0,0 +1,29 @@
+import sys
+import winreg
+from pathlib import Path
+
+
+def get_download_directory():
+    if sys.platform == 'win32':
+        # 打开注册表项
+        key = winreg.OpenKey(winreg.HKEY_CURRENT_USER,
+                             r'Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders')
+
+        try:
+            # 读取 "Downloads" 路径
+            download_dir, _ = winreg.QueryValueEx(key, '{374DE290-123F-4565-9164-39C4925E467B}')
+
+            # 将路径从注册表中的格式转换为标准格式
+            download_dir = Path(download_dir).resolve()
+
+        finally:
+            # 关闭注册表项
+            winreg.CloseKey(key)
+    else:
+        # 对于非 Windows 系统，使用 ~\Downloads 作为默认下载目录
+        home_dir = Path.home()
+        download_dir = home_dir / 'Downloads'
+    dir_path = Path(download_dir)
+    if not dir_path.exists():
+        dir_path.mkdir(parents=True, exist_ok=True)
+    return str(download_dir)

tool/hash/Segwit.py

@@ -0,0 +1,72 @@
+import hashlib
+import bech32
+
+# https://liaoxuefeng.com/books/blockchain/bitcoin/segwit/index.html
+
+def hash160(data):
+    """
+    计算输入数据的SHA-160哈希值。
+
+    参数:
+    data (bytes): 输入数据
+
+    返回:
+    bytes: SHA-160哈希值
+    """
+    return hashlib.new('ripemd160', hashlib.sha256(data).digest()).digest()
+
+def encodeSegwit(data_bytes, hrp="fst"):
+    """
+    将字节数据编码为Bech32格式。
+
+    参数:
+    hrp (str): 人类可读部分 (Human-readable part)
+    data_bytes (bytes): 要编码的数据
+
+    返回:
+    str: Bech32编码后的字符串
+    """
+
+    # 将字节转换为5位整数列表
+    data_ints = bech32.convertbits(hash160(data_bytes), 8, 5)
+    if not data_ints:
+        raise ValueError("Failed to convert bytes to 5-bit integers")
+
+    return bech32.bech32_encode(hrp, data_ints)
+
+
+def verifySegwit(bech32_str):
+    """
+    验证Bech32编码的字符串是否有效。
+
+    参数:
+    bech32_str (str): Bech32编码的字符串
+
+    返回:
+    bool: 如果字符串有效则返回True，否则返回False
+    """
+    try:
+        hrp, data_ints = bech32.bech32_decode(bech32_str)
+        if not hrp or not data_ints:
+            return False
+
+        # 将5位整数列表转换回字节
+        data_bytes = bech32.convertbits(data_ints, 5, 8, False)
+        if not data_bytes:
+            return False
+
+        return True
+    except Exception as e:
+        print(f"Verification failed: {e}")
+        return False
+
+
+# 示例用法
+if __name__ == "__main__":
+    message = b"Hello, Bech32!"
+
+    encoded = encodeSegwit(message)
+    print(f"Encoded: {encoded}")
+
+    is_valid = verifySegwit(encoded)
+    print(f"Is valid: {is_valid}")