我有用Java编写的加密代码，我正在尝试用Python编写它，但问题是Python加密和解密工作正常，但是当尝试使用Python解密Java加密字符串时，它不起作用。
这是我的Java代码。
import lombok.extern.slf4j.Slf4j;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.util.Arrays;
import java.util.Base64;
@Slf4j
public class EncryptUsingAES {
/**
* This function takes a String as input and encrypts it using AES Algorithm
* @param stringToEncrypt
* @param publicKey
* @return
*/
public String returnEncryptedString(String stringToEncrypt, String publicKey) {
Security.addProvider(new BouncyCastleProvider());
try{
SecureRandom sr = new SecureRandom();
byte[] salt = new byte[8];
sr.nextBytes(salt);
final byte[][] keyAndIV = generateKeyAndIV(salt, publicKey.getBytes(StandardCharsets.UTF_8), MessageDigest.getInstance("MD5"));
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", BouncyCastleProvider.PROVIDER_NAME);
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(keyAndIV[0], "AES"), new IvParameterSpec(keyAndIV[1]));
byte[] encryptedData = cipher.doFinal(stringToEncrypt.getBytes(StandardCharsets.UTF_8));
byte[] prefixAndSaltAndEncryptedData = new byte[16 + encryptedData.length];
System.arraycopy("Salted__".getBytes(StandardCharsets.UTF_8), 0, prefixAndSaltAndEncryptedData, 0, 8);
System.arraycopy(salt, 0, prefixAndSaltAndEncryptedData, 8, 8);
System.arraycopy(encryptedData, 0, prefixAndSaltAndEncryptedData, 16, encryptedData.length);
String encryptedString = URLEncoder.encode(Base64.getEncoder().encodeToString(prefixAndSaltAndEncryptedData),"UTF-8");
return encryptedString;
} catch (Exception e) {
return null;
}
}
/**
* this function creates key Initialisation Vector which is required for AES Encryption
* @param salt
* @param password
* @param md
* @return
*/
protected byte[][] generateKeyAndIV(byte[] salt, byte[] password, MessageDigest md) {
int keyLength = 32;
int ivLength = 16;
int iterations = 1;
int digestLength = md.getDigestLength();
int requiredLength = (keyLength + ivLength + digestLength - 1) / digestLength * digestLength;
byte[] generatedData = new byte[requiredLength];
int generatedLength = 0;
try {
md.reset();
while (generatedLength < keyLength + ivLength) {
if (generatedLength > 0)
md.update(generatedData, generatedLength - digestLength, digestLength);
md.update(password);
if (salt != null)
md.update(salt, 0, 8);
md.digest(generatedData, generatedLength, digestLength);
for (int i = 1; i < iterations; i++) {
md.update(generatedData, generatedLength, digestLength);
md.digest(generatedData, generatedLength, digestLength);
}
generatedLength += digestLength;
}
byte[][] result = new byte[2][];
result[0] = Arrays.copyOfRange(generatedData, 0, keyLength);
if (ivLength > 0)
result[1] = Arrays.copyOfRange(generatedData, keyLength, keyLength + ivLength);
return result;
} catch (DigestException e) {
log.error(OrderStatusSmsTrackerConstants.ORDER_STATUS_SMS_TRACKER_SERVICE+
return null;
} finally {
Arrays.fill(generatedData, (byte)0);
}
}
}
这是我的Python加密和解密代码，
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
from Crypto.Random import get_random_bytes
import base64
import urllib.parse
import hashlib
import logging
class EncryptUsingAES:
def return_encrypted_string(self, string_to_encrypt, public_key):
try:
salt = get_random_bytes(8)
key_and_iv = self.generate_key_and_iv(salt, public_key.encode('utf-8'), hashlib.md5)
cipher = AES.new(key_and_iv[0], AES.MODE_CBC, iv=key_and_iv[1])
encrypted_data = cipher.encrypt(pad(string_to_encrypt.encode('utf-8'), AES.block_size))
prefix_and_salt_and_encrypted_data = b"Salted__" + salt + encrypted_data
encrypted_string = urllib.parse.quote(base64.b64encode(prefix_and_salt_and_encrypted_data))
return encrypted_string
except Exception as e:
logging.error("Error when encrypting: " + str(e))
return None
def return_decrypted_string(self, encrypted_string, public_key):
try:
encrypted_data = base64.b64decode(urllib.parse.unquote(encrypted_string))
salt = encrypted_data[8:16]
encrypted_data = encrypted_data[16:]
key_and_iv = self.generate_key_and_iv(salt, public_key.encode('utf-8'), hashlib.md5)
cipher = AES.new(key_and_iv[0], AES.MODE_CBC, iv=key_and_iv[1])
decrypted_data = unpad(cipher.decrypt(encrypted_data), AES.block_size)
return decrypted_data.decode('utf-8')
except Exception as e:
logging.error("Error when decrypting: " + str(e))
return None
def generate_key_and_iv(self, salt, password, md):
key_length = 32
iv_length = 16
iterations = 1
digest_length = md().digest_size
required_length = (key_length + iv_length + digest_length - 1) // digest_length * digest_length
generated_data = bytearray([0]) * required_length
generated_length = 0
try:
md = md()
while generated_length < key_length + iv_length:
if generated_length > 0:
md.update(generated_data[generated_length - digest_length:generated_length])
md.update(password)
if salt is not None:
md.update(salt[:8])
generated_data[generated_length:generated_length + digest_length] = md.digest()
for i in range(1, iterations):
md.update(generated_data[generated_length:generated_length + digest_length])
generated_data[generated_length:generated_length + digest_length] = md.digest()
generated_length += digest_length
key = generated_data[:key_length]
iv = generated_data[key_length:key_length + iv_length]
return key, iv
except Exception as e:
logging.error("Error when generating key and IV: " + str(e))
return None
finally:
for i in range(len(generated_data)):
generated_data[i] = 0
任何人都可以帮我解决这个问题吗？
该错误在于密钥派生中：摘要的 Java 实现在
digest()generate_key_and_iv()中需要进行以下更改：
...
try:
while generated_length < key_length + iv_length:
h = md() # create new instance (1.)
if generated_length > 0:
h.update(generated_data[generated_length - digest_length:generated_length])
h.update(password)
if salt is not None:
h.update(salt[:8])
generated_data[generated_length:generated_length + digest_length] = h.digest()
for i in range(1, iterations):
h = md() # create new instance (2.)
h.update(generated_data[generated_length:generated_length + digest_length])
generated_data[generated_length:generated_length + digest_length] = h.digest()
generated_length += digest_length
...
对于测试（并且仅用于测试），两种实现中都可以使用静态盐。使用相同的明文和密码，两种加密都会提供相同的密文。
此外，应将
safe=''作为
urllib.parse.quote()中的第二个参数传递，以便
/ 也被转义序列替换。