python-RSA加密与java-Cipher加密适配
在进行login操作时，经常需要对登录密码进行加密，这时涉及到了两种开发语言的加密兼容适配问题。我们先来看java-Cipher加密
【java-Cipher加密介绍】
一、Cipher类提供了加密和解密功能，利用Cipher类可完成des、des3、rsa和aes加密。通过获取Cipher类对象
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");对象对应解释为：“算法/模式/填充模式” -- “DES/CBC/PKCS5Padding”
二、常见有以下参数：
* AES/CBC/NoPadding (128)
* AES/CBC/PKCS5Padding (128)
* AES/ECB/NoPadding (128)
* AES/ECB/PKCS5Padding (128)
* DES/CBC/NoPadding (56)
* DES/CBC/PKCS5Padding (56)
* DES/ECB/NoPadding (56)
* DES/ECB/PKCS5Padding (56)
* DESede/CBC/NoPadding (168)
* DESede/CBC/PKCS5Padding (168)
* DESede/ECB/NoPadding (168)
* DESede/ECB/PKCS5Padding (168)
* RSA/ECB/PKCS1Padding (1024, 2048)
* RSA/ECB/OAEPWithSHA-1AndMGF1Padding (1024, 2048)
* RSA/ECB/OAEPWithSHA-256AndMGF1Padding (1024, 2048)(1)加密算法有：AES，DES，DESede(DES3)和RSA 四种
(2) 模式有CBC(有向量模式)和ECB(无向量模式)，向量模式可以简单理解为偏移量，使用CBC模式需要定义一个IvParameterSpec对象
(3) 填充模式:
* NoPadding: 加密内容不足8位用0补足8位, Cipher类不提供补位功能，需自己实现代码给加密内容添加0, 如{65,65,65,0,0,0,0,0}
* PKCS5Padding: 加密内容不足8位用余位数补足8位, 如{65,65,65,5,5,5,5,5}或{97,97,97,97,97,97,2,2}; 刚好8位补8位8
代码示例：
private static byte[] encryptByPublic(byte[] data, PublicKey key) throws GeneralSecurityException{
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher.init(Cipher.ENCRYPT_MODE, key);
return cipher.doFinal(data);
}示例代码中padding表示的意思是什么呢？
看下述的一个示例：
RSA/ECB/OEAPWithSHA-1AndMGF1Padding在SUN JCE是这样解释的：RSA/ECB/OEAPWithSHA-1AndMGF1Padding中的HASH=SHA1 MGF1=SHA1
那接下来我们来了解python的rsa加密。
【python-RSA加密介绍】
一、一般在python中有RSA加密的第三方库有rsa、Crypto和Cryptodemo、Cryptography。
示例代码1：
#!/usr/bin python3
# _*_ coding:utf-8 _*_
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5
import base64
def encryptDemo(data):
with open("./publickey.pem", "rb") as f:
public_code = f.read()
public_key = RSA.importKey(public_code)
cipher = PKCS1_v1_5.new(public_key)
encrpt = base64.b64encode(cipher.encrypt(str(data).encode())).decode()
return encrpt在示例代码中采用了Crypto库来实现RSA的加密，引用了PKCS1_v1_5的padding模式，与java Cipher类中的RSA/ECB/PKCS1Padding 等同。
示例代码2：
#!/usr/bin python3
# _*_ coding:utf-8 _*_
import rsa
import base64
def encryptDemo(data):
with open("./publickey.pem", "rb") as f:
public_code = f.read()
public_key = rsa.PublicKey.load_pcks1(public_code )
encrpt = base64.b64encode(rsa.encrypt(str(data).encode("utf-8"), public_key)).decode()
return encrpt上述两个示例都是通过读取pem文件来处理RSA加密。
二、加密密钥为字符串的处理
一般的加密串
MII89sdJS6KijPS0NB9AtyUVC7BAQEFAAOCAQ8AMIIBCgKCAQEOkISJAH87D7Cb6AvquOFRT8AeI5cscJ********************************************************************************************************************************************************************************7RHCUSDJOAinHDBV遇到加密密钥为字符串，第一种方式可通过补全pem格式的头部和尾部,如
-----BEGIN PUBLIC KEY-----
MII*******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************BUS870B9Ay6BA
-----END PUBLIC KEY-----示例代码3：
#!/usr/bin python3
# _*_ coding:utf-8 _*_
import rsa
import base64
def encryptDemo(data):
public_data = "MII89sdJS6KijPS0NB9AtyUVC7BAQEFAAOCAQ8AMIIBCgKCAQEOkISJAH87D7Cb6AvquOFRT8AeI5cscJ********************************************************************************************************************************************************************************7RHCUSDJOAinHDBV"
new_data = "-----BEGIN PUBLIC KEY-----\n" + public_data + "-----END PUBLIC KEY-----"
public_key = rsa.PublicKey.load_pcks1_openssl_pem(new_data)
encrpt = base64.b64encode(rsa.encrypt(str(data).encode("utf-8"), public_key)).decode()
return encrpt第二种方式同base64的编码来加载
示例代码4：
#!/usr/bin python3
# _*_ coding:utf-8 _*_
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5
import base64
def encryptDemo(data):
public_data = "MII89sdJS6KijPS0NB9AtyUVC7BAQEFAAOCAQ8AMIIBCgKCAQEOkISJAH87D7Cb6AvquOFRT8AeI5cscJ********************************************************************************************************************************************************************************7RHCUSDJOAinHDBV"
public_key = RSA.importKey(base64.b64encode(public_data))
cipher = PKCS1_v1_5.new(public_key)
encrpt = base64.b64encode(cipher.encrypt(str(data).encode("utf-8"),public_key)).decode()
return encrpt三、java Cipher类中的RSA/ECB/OAEPWithSHA-256AndMGF1Padding 兼容
首先RSA/ECB/OAEP模式，在python的Crypto或Cryptodemo库中两种方式PKCS1_v1_5和PKCS1_OAEP。
其次在前面我们已经知道了padding模式的解释，它指的是SHA256算法+sha1。
接下来分析在PKCS1_OAEP的new方法源码：
def new(key, hashAlgo=None, mgfunc=None, label=b'', randfunc=None):
"""Return a cipher object :class:`PKCS1OAEP_Cipher` that can be used to perform PKCS#1 OAEP encryption or decryption.
:param key:
The key object to use to encrypt or decrypt the message.
Decryption is only possible with a private RSA key.
:type key: RSA key object
:param hashAlgo:
The hash function to use. This can be a module under `Cryptodome.Hash`
or an existing hash object created from any of such modules.
If not specified, `Cryptodome.Hash.SHA1` is used.
:type hashAlgo: hash object
:param mgfunc:
A mask generation function that accepts two parameters: a string to
use as seed, and the lenth of the mask to generate, in bytes.
If not specified, the standard MGF1 consistent with ``hashAlgo`` is used (a safe choice).
:type mgfunc: callable
:param label:
A label to apply to this particular encryption. If not specified,
an empty string is used. Specifying a label does not improve
security.
:type label: bytes/bytearray/memoryview
:param randfunc:
A function that returns random bytes.
The default is `Random.get_random_bytes`.
:type randfunc: callable
"""
if randfunc is None:
randfunc = Random.get_random_bytes
return PKCS1OAEP_Cipher(key, hashAlgo, mgfunc, label, randfunc)在new函数中hashAlgo参数, mgfunc参数默认都是为None，而java Cipher类中的RSA/ECB/OAEPWithSHA-256AndMGF1Padding中要用到SHA256和SHA1
示例代码5：推荐Cryptodome库
#!/usr/bin python3
# _*_ coding:utf-8 _*_
from Cryptodome.Signature import pss
from Cryptodome.Hash import SHA256, SHA1
from Cryptodome.Cipher import PKCS1_OAEP
from Cryptodome.PublicKey import RSA
import base64
def encrtypt(data, public_code):
public_key = RSA.importKey(base64.b64decode(public_code))
cipher = PKCS1_OAEP.new(public_key, hashAlgo=SHA256, mgfunc=lambda x, y:pss.MGF1(x, y, SHA1))
encrypt_data = base64.b64encode(cipher.encrypt(str(data).encode())).decode()
return encrypt_data【注】RSA加密是有长度限定的，所以当data长度过长时，需要做分段加密
示例代码6：
#!/usr/bin python3
# _*_ coding:utf-8 _*_
from com import client
from Cryptodome.Signature import pss
from Cryptodome.Hash import SHA256, SHA1
from Cryptodome.Cipher import PKCS1_OAEP
from Cryptodome.PublicKey import RSA
import base64
def encrtypt(data, public_code, length):
public_key = RSA.importKey(base64.b64decode(public_code))
encrypt_data = []
cipher = PKCS1_OAEP.new(public_key, hashAlgo=SHA256, mgfunc=lambda x, y:pss.MGF1(x, y, SHA1))
for i in range(0, len(str(data)), length):
encrypt_data.append(base64.b64encode(cipher.encrypt(str(data)[i:i + length].encode())).decode())
return encrypt_data以上为本次关于python RSA加密与java Cipher类的兼容说明，如有错误之处烦请在评论区指出，也欢迎大家在评论参与讨论。谢谢！
[Cipher部分知识引用] https://blog.csdn.net/SeptDays/article/details/121102385