如何将 SHA256 对象保存到文件中？

Question

（我在 python 3.10.4 中使用 pycryptodome 完成所有这些操作）

我正在尝试执行此过程：

获取文件的哈希值
将该散列保存在某处
加载该散列并使用私钥执行 RSA 签名

我在第 3 步的位置遇到问题，我必须将它保存为字符串，这在第 3 步中不起作用。

我试过使用泡菜，但我越来越 “不能腌制包含指针的 ctypes 对象”

生成哈希的代码：

sha256 = SHA256.new()
with open(fileDir, 'rb') as f:
    while True:
        data = f.read(BUF_SIZE)
        if not data:
            break
        sha256.update(data)

执行签名的代码：

get_file(fileName + '.hash', directory)
with open(currentDir + '/client_files/downloaded/' + fileName + '.hash', 'r') as f:
    hash_data = f.read()    
with open(currentDir + '/client_files/private_key.pem', 'rb') as f:
    private_key = RSA.importKey(f.read())
print(private_key)    
signer = PKCS1_v1_5.new(private_key)
signature = signer.sign(hash_data)

我遇到的错误：

Traceback (most recent call last):
  File "c:\Users\User\Documents\Coding\VSCode Projects\practiceGround\sec_cloud_project\client\client.py", line 168, in <module>
    main()
  File "c:\Users\User\Documents\Coding\VSCode Projects\practiceGround\sec_cloud_project\client\client.py", line 163, in main
    sign(fileName, 'worker_test_files')
  File "c:\Users\User\Documents\Coding\VSCode Projects\practiceGround\sec_cloud_project\client\client.py", line 120, in sign
    signature = signer.sign(hash_data)
  File "C:\Users\User\anaconda3\envs\nscc_project\lib\site-packages\Crypto\Signature\pkcs1_15.py", line 77, in sign
    em = _EMSA_PKCS1_V1_5_ENCODE(msg_hash, k)
  File "C:\Users\User\anaconda3\envs\nscc_project\lib\site-packages\Crypto\Signature\pkcs1_15.py", line 191, in _EMSA_PKCS1_V1_5_ENCODE
    digestAlgo = DerSequence([ DerObjectId(msg_hash.oid).encode() ])
AttributeError: 'str' object has no attribute 'oid'

请注意，我目前正在将原始散列作为字符串保存到文本文件中。如果我尝试使用 pickle 将对象保存为一个整体，我会收到此错误

with open(currentDir + '/worker_files/sha256.pickle', 'wb') as f:
    pickle.dump(sha256, f)

Traceback (most recent call last):
  File "c:\Users\User\Documents\Coding\VSCode Projects\practiceGround\sec_cloud_project\worker\worker.py", line 188, in <module>
    main()
  File "c:\Users\User\Documents\Coding\VSCode Projects\practiceGround\sec_cloud_project\worker\worker.py", line 179, in main
    hash_file(fileName, 'worker_test_files')
  File "c:\Users\User\Documents\Coding\VSCode Projects\practiceGround\sec_cloud_project\worker\worker.py", line 55, in hash_file
    pickle.dump(sha256, f)
ValueError: ctypes objects containing pointers cannot be pickled

Answer 1

感谢@Topaco。更改为使用 Cyptography 进行散列和签名似乎有效。

用 Cryptography 散列，用 pickle 转储到一个文件，然后再次用 Cryptography 加载和签名。

如何将 SHA256 对象保存到文件中？

How to save SHA256 object to a file?

python

hash

aes

rsa

sha256