Python 实现RSA加解密文本文件

pip install pycryptodomex -i https://pypi.tuna.tsinghua.edu.cn/simple/

import base64
from Cryptodome import Random
from Cryptodome.PublicKey import RSA
from Cryptodome.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
from Cryptodome.Signature import PKCS1_v1_5 as Signature_pkcs1_v1_5

# 伪随机数生成器
random_generator = Random.new().read
# rsa算法生成实例
rsa = RSA.generate(1024, random_generator)
private_pem = str(rsa.exportKey(), encoding="utf-8")
with open("client-private.pem", "w") as f:
    f.write(private_pem)
  
public_pem = str(rsa.publickey().exportKey(), encoding="utf-8")
with open("client-public.pem", "w") as f:
    f.write(public_pem)'''

def rsa_encrypt(plaintext, pub_key):
    '''
    rsa 加密
    :param plaintext: 明文
    :param pub_key:公钥
    '''
    message = plaintext.encode("utf-8")
    length = len(message)
    default_length = 117  # 1024/8 - 11 1024为密钥长度
    rsakey = RSA.importKey(pub_key)
    cipher = Cipher_pkcs1_v1_5.new(rsakey)
    # 不需要切分
    if length <= default_length:
        return default_rsa_encrypt(cipher, message)
    # 需要切分
    offset = 0
    result = []
    while length - offset > 0:
        if length - offset > default_length:
            result.append(default_rsa_encrypt(
                cipher, message[offset:offset+default_length]))
        else:
            result.append(default_rsa_encrypt(cipher, message[offset:]))
        offset += default_length
    return "\n".join(result)
  
def default_rsa_encrypt(cipher, message):
    ciphertext = base64.b64encode(cipher.encrypt(message))
    # print(b"ciphertext:"+ciphertext)
    ciphertext_decode = ciphertext.decode("utf-8")
    # print("ciphertext_decode:"+ciphertext_decode)
    return ciphertext_decode

def rsa_decrypt(ciphertext, priv_key):
    '''
    rsa 解密
    :param ciphertext:密文
    :param priv_key:私钥
    '''
    message = base64.b64decode(ciphertext)
    length = len(message)
    default_length = 128
    rsakey = RSA.importKey(priv_key)
    cipher = Cipher_pkcs1_v1_5.new(rsakey)
    if length <= default_length:
        return default_rsa_decrypt(cipher, message)
    # 需要分段
    offset = 0
    result = []
    while length - offset > 0:
        if length - offset > default_length:
            result.append(rsa_decrypt(
                cipher, message[offset:offset+default_length]))
        else:
            result.append(rsa_decrypt(cipher, message[offset:]))
        offset += default_length
    decode_message = [x.decode("utf-8") for x in result]
    return "".join(decode_message)
  
def default_rsa_decrypt(cipher, message):
    plaintext = cipher.decrypt(message, random_generator)
    # print(b"plaintext:"+plaintext)
    plaintext_decode = plaintext.decode("utf-8")
    # print("plaintext_decode:"+plaintext_decode)
    return plaintext_decode

def rsa_encrypt_file(file_path, save_path, pub_key):
    '''
    rsa 加密文件
    :param file_path:需要加密文件路径
    :param save_path:加密之后存放的文件路径
    :param pub_key:公钥
    '''
    with open(file_path, "r", encoding="utf-8") as f:
        line = f.readline()  # 读取一行
        while line:
            context = rsa_encrypt(line, pub_key)  # 加密切割后的字符
            with open(save_path, "a", encoding="utf-8") as w:
                w.write(context+"\n")
        line = f.readline()
def rsa_decrypt_file(file_path,save_path,priv_key):
    '''
    rsa 解密文件
    :file_path:需要解密的文件路径
    :save_path:解密之后存放的文件路径
    :priv_key:私钥
    '''
    with open(file_path,"r",encoding="utf-8") as f:
        line = f.readline()
        while line:
            context = rsa_decrypt(line.strip("\n"),priv_key)
            with open(save_path,"a",encoding="utf-8") as w:
                w.write(context)
            line = f.readline()

def cut_string(message,length = 117):
    result = []
    temp_char = []
    for msg in message:#遍历每一个字符
        msg_encode = msg.encode("utf-8")#对每一个字符编码
        temp_encode = "".join(temp_char).encode("utf-8")#累计编码之后的字节数
        if len(temp_encode) + len(msg_encode) <= length:#如果小于约定的长度，加添加入结果集
            temp_char.append(msg)
        else:#如果已经超过了约定的长度，就添加入下一个结果集
            result.append("".join(temp_char))
            temp_char.clear()
            temp_char.append(msg)
    result.append("".join(temp_char))
    return result

def rsa_encrypt_file(file_path,save_path,pub_key):
    '''
    rsa 加密文件
    :param file_path:需要加密文件路径
    :param save_path:加密之后存放的文件路径
    :param pub_key:公钥
    '''
    with open(file_path,"r",encoding="utf-8") as f:
        line = f.readline() #读取一行
        while line:
            cut_lines = cut_string(line) # 切割字符 保证汉字不被切割
            for cut_line in cut_lines:
                context = rsa_encrypt(cut_line,pub_key) #加密切割后的字符
                with open(save_path,"a",encoding="utf-8") as w:
                    w.write(context+"\n")
            line = f.readline()

def rsa_encrypt_binfile(file_path,save_path,pub_key):
  '''
  rsa 加密二进制文件
  :param file_path:需要加密文件路径
  :param save_path:加密之后存放的文件路径
  :param pub_key:公钥
  '''
  with open(file_path, 'rb') as f:
    message = f.read()
  length = len(message)
  default_length = 117 # 1024/8 - 11 1024为密钥长度
  rsakey = RSA.importKey(pub_key)
  cipher = Cipher_pkcs1_v1_5.new(rsakey)
  # 不需要切分
  result = []
  if length <= default_length:
    result.append(base64.b64encode(cipher.encrypt(message)))

  # 需要切分
  offset = 0
  while length - offset > 0:
    if length - offset > default_length:
      result.append(base64.b64encode(cipher.encrypt(message[offset:offset+default_length])))
    else:
      result.append(base64.b64encode(cipher.encrypt(message[offset:])))
    offset += default_length
  
  with open(save_path,"ab+") as w:
    for ciphertext in result:
      ciphertext += b"\n"
      w.write(ciphertext)

def rsa_decrypt_binfile(file_path,save_path,priv_key):
  '''
  rsa 解密二进制文件
  :file_path:需要解密的文件路径
  :save_path:解密之后存放的文件路径
  :priv_key:私钥
  '''
  with open(file_path,"rb") as f:
    line = f.readline()
    while line:
      message = base64.b64decode(line.strip(b"\n"))
      rsakey = RSA.importKey(priv_key)
      cipher = Cipher_pkcs1_v1_5.new(rsakey)
      plaintext = cipher.decrypt(message, random_generator)
      with open(save_path, 'ab+') as w: #追加写入
        w.write(plaintext)
      line = f.readline()