Python uses various encryption algorithms [MD5 | AES | RSA]

foreword

With the change of work items, I found that the more times I used the encryption algorithm, because my memory is poor (that is, food), I need to read other people's blogs every time. This article is specially set up to record the use of python An encrypted record.

md5 algorithm (hash)

# -*- coding:utf-8 -*-
import hashlib
# 该函数实现对指定字符串取md5值
def getmd5(str):
    m = hashlib.md5()
    m.update(str.encode("utf-8"))
    return m.hexdigest()
# 这里需要注意一个点，那就说如果要对json类型字符串进行hash,需要处理：与值之间的空格，具体参考我的另一篇文章：https://blog.csdn.net/weixin_42380348/article/details/121795572
print(getmd5('abcderg'))

AES encryption and decryption (symmetric)

1. AES has 5 encryption modes. AES.MODE_CBC is used here. This mode needs to specify a vi, and vi refers to the initialization vector. If the initialization vector is not specified, the encryption results are inconsistent every time, and the same initialization is also required for decryption. Vector
2. The AES encryption algorithm can only be encrypted in Block mode, and the block size is 16Byte, so the encrypted plaintext needs to be an integer multiple of 16. If it is insufficient, the padding needs to be a multiple of 16. 3. The key size of AES encryption can be, 16
, 24, 32, corresponding to 128bit, 192bit, 256bit.

Note: AES 5 encryption modes
1. Electronic Codebook Book (ECB)
2. Cipher Block Chaining (CBC)
3. Calculator mode (Counter (CTR))
4. Cipher feedback mode (Cipher FeedBack (CFB))
5. Output Feedback Mode (Output FeedBack (OFB))

import base64
from Crypto.Cipher import AES
def get_enAes(data):
    # 解决加密明文不是16的整数倍问题
    pad = lambda s: s + (16 - len(s) % 16) * chr(16 - len(s) % 16)
    # 去除加密明文右侧的空白符
    data = pad(data.rstrip())
    # 这个用作iv,初始化向量
    key16 = 'de03a088357803gf'
    # 这个是AES加密用到的key
    key32 = 'a0ea98d098989loki96709oipd388jgn'
    # 统一编码一下
    iv = key16.encode('utf-8')
    key = key32.encode('utf-8')
    data1 = data.encode('utf-8')
    # 定义加密模式
    model = AES.MODE_CBC
    # 创建AES对象
    endata = AES.new(key, model, iv)
    # 进行加密
    endata_res = endata.encrypt(data1)
    # 将返回的字节型数据转进行base64编码
    res = base64.b64encode(endata_res)
    return res.decode()
def get_deAes(data):
    # 这个用作iv,初始化向量
    key16 = '2f03e088357803f1'
    # 这个是AES加密用到的key
    key32 = 'a0ea98d540989e5aa96709oipd388bjk'
    iv = key16.encode('utf-8')
    key = key32.encode('utf-8')
    # 定义加密模式
    model = AES.MODE_CBC
    # 创建AES对象
    dedata = AES.new(key, model, iv)
    #进行解密
    res = dedata.decrypt(base64.b64decode(data))
    return res.decode()

endata = get_enAes('123123123')
print("对123123123的加密结果：",endata)
print("AES解密结果：",get_deAes(endata))

Rsa asymmetric addition solution (applicable to interface testing of java projects)

The rsa encryption this time originated from a penetration test for the interface. The interface uses rsa to encrypt key data, and then uses rsa to sign. The whole process designs two pairs of secret keys. The following figure is the rsa encryption developed for me in java Example (there is a complete example, not shown here), I need to implement encryption and signature based on this example and conduct penetration testing.

Python corresponding rsa encryption method and decryption example

# -*- coding:utf-8 -*-
import Crypto
import base64
from Crypto.PublicKey import RSA
# 关键在这里 使用Crypto模块中的pkcs1_v1_5。就是对应pkcs8的格式了
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5

# 前提
# PKCS8EncodedKeySpec
# X509EncodedKeySpec
# 1024
# 签名：md5withrsa

# rsa加密
# 参考https://blog.csdn.net/soulwyb/article/details/111354661
def enRsa(msg,pub_key):
    rsakey = RSA.importKey(pub_key)
    cipher = Cipher_pkcs1_v1_5.new(rsakey)
    encrypt_bytes = cipher.encrypt(msg.encode(encoding='utf-8'))
    cipher_text = base64.b64encode(encrypt_bytes)
    # return request.quote(cipher_text)
    return cipher_text.decode()

# 分段加密函数，调用了下方获取公钥长度的函数
def enRsaLog(msg,pub_key):
    length = len(msg)
    public_key = RSA.importKey(pub_key)
    default_length = int(get_max_length(public_key))
    pub_obj = Cipher_pkcs1_v1_5.new(public_key)
    # 长度不用分段
    if length < default_length:
        return base64.b64encode(pub_obj.encrypt(msg.encode(encoding='utf-8')))
    # 需要分段
    offset = 0
    res = []
    while length - offset > 0:
        if length - offset > default_length:
            res.append(pub_obj.encrypt(msg[offset:offset + default_length].encode(encoding='utf-8')))
        else:
            res.append(pub_obj.encrypt(msg[offset:].encode(encoding='utf-8')))
        offset += default_length

    byte_data = b''.join(res)
    return base64.b64encode(byte_data)

# 获取rsa能够一次能够加密的长度
def get_max_length(rsa_key, encrypt=True):
    blocksize = Crypto.Util.number.size(rsa_key.n) / 8  # :param rsa_key: 钥匙.
    reserve_size = 11  # 预留位为11
    if not encrypt:  # 解密时不需要考虑预留位     # :param encrypt: 是否是加密.
        reserve_size = 0
    maxlength = blocksize - reserve_size
    return maxlength

#--=======================================rsa解密==========================================================--
# 分段解密：
def dec_rsa(rsa_msg,pri_key):
    msg = base64.b64decode(rsa_msg)
    length = len(msg)
    private_key = RSA.importKey(pri_key)
    max_length = int(get_max_length(private_key, False))

    private_obj = Cipher_pkcs1_v1_5.new(private_key)
    # 长度不用分段
    if length < max_length:
        return b''.join(private_obj.decrypt(msg, b'xyz'))
    # 需要分段
    offset = 0
    res = []
    while length - offset > 0:
        if length - offset > max_length:
            res.append(private_obj.decrypt(msg[offset:offset + max_length], b'xyz'))
        else:
            res.append(private_obj.decrypt(msg[offset:], b'xyz'))
        offset += max_length

    return res


if __name__ == '__main__':
    msg = "12345678909090909090080080845678909090909090080084567890909090909008008456789090909090900800845678909090909090080084567890909090909008008456789090909090900800845678909090909090080084567890909090909008008"
    pub_key = """-----BEGIN PUBLIC KEY-----
    MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDK8ry98taCozOfcmv2KlEOE5EvJXChpsa/N4fa6CBa/HLjz4A3A7aviP6qhhaW1h8kKywSZyjQtplURIb0HkSrZGMTVehTtk641rxtEutioARdN/2q/XoHS6fL+OheVXOs9c7uV3bflWybqtCg5i4FY1CIwvbpVArRcXxo6U2k2wIDAQAB
    -----END PUBLIC KEY-----"""
    pri_key = """-----BEGIN PRIVATE KEY-----
    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
    -----END PRIVATE KEY-----
    """
    endata = enRsaLog(msg,pub_key)
    print("rsa加密结果" , endata)
    print("rsa解密结果" , dec_rsa(endata,pri_key))