我在解密使用 RSA 生成的公钥 (.jks) 编码的 128 位 AES 密钥时收到 BadPaddingExcept

Question

package demo123;
import java.io.File;
import java.io.FileInputStream;
import java.nio.file.Files;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

用于 RSA-AES 加密/解密的 Java 8 示例。

公共类 AESwithRSA {

public static void main(String[] args) throws Exception {
String plainText = "{"scope":"payments","x-mig-bank": "ICICI","x-mig-channel": "RC","tpp_redirect_uri": "www.tpp-app.com?query=123","x-tpp-client-id": "Ck234567890112","tpp-app-name": "amazon","Consent Id": "d25a6f26-3ad5-4dd8-96fd-2582abfa3f58","Type": "Domestic Payment" }";

使用 RSA 生成公钥和私钥

Key privateKey = getPrivate("KeyPair/privateKey.jks");
System.out.println("Private key success");
System.out.println("Private key :" + privateKey);
Key publicKey = getPublic("KeyPair/publicKey.");
System.out.println("Public key success");
System.out.println("Public key :" + publicKey);

首先创建一个 AES 密钥

String secretAESKeyString = getSecretAESKeyAsString();
System.out.println("Secret Key "+secretAESKeyString);

使用 AES 密钥加密我们的数据

String encryptedText = encryptTextUsingAES(plainText, secretAESKeyString);
System.out.println("Encrypted text "+encryptedText);

使用 RSA 私钥加密 AES 密钥

byte[] encryptedAESKeyString = encryptAESKey(secretAESKeyString, publicKey);
System.out.println("Encrypted AES key with RSA "+encryptedAESKeyString);

首先使用 RSA 公钥解密 AES 密钥

String decryptedAESKeyString = decryptAESKey(encryptedAESKeyString, privateKey);
System.out.println("Decrypted AES key with RSA "+decryptedAESKeyString);

现在使用解密的 AES 密钥解密数据！

String decryptedText = decryptTextUsingAES(encryptedText, decryptedAESKeyString);

显示所有输出

System.out.println("input: " + encryptedText);
System.out.println("AES Key: " + secretAESKeyString);
System.out.println("decrypted: " + decryptedText);
System.out.println("Text New:" + textNew);
System.out.println("Encrypted New:" + encryptedTextNew);
//System.out.println("Decrypted New:" + decryptedTextNew);
}

创建一个新的 AES 密钥。使用 128 位(弱(

public static String getSecretAESKeyAsString() throws Exception {
KeyGenerator generator = KeyGenerator.getInstance("AES");
generator.init(128); // The AES key size in number of bits
SecretKey secKey = generator.generateKey();
String encodedKey = Base64.getEncoder().encodeToString(secKey.getEncoded());
return encodedKey;
}

使用 AES 密钥加密文本

public static String encryptTextUsingAES(String plainText, String aesKeyString) throws Exception {
byte[] decodedKey = Base64.getDecoder().decode(aesKeyString);
SecretKey originalKey = new SecretKeySpec(decodedKey, 0, decodedKey.length, "AES");
// AES defaults to AES/ECB/PKCS5Padding in Java 7
Cipher aesCipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
aesCipher.init(Cipher.ENCRYPT_MODE, originalKey);
byte[] byteCipherText = aesCipher.doFinal(plainText.getBytes());
return Base64.getEncoder().encodeToString(byteCipherText);
}

使用 AES 密钥解密文本

public static String decryptTextUsingAES(String encryptedText, String aesKeyString) throws Exception {
byte[] decodedKey = Base64.getDecoder().decode(aesKeyString);
SecretKey originalKey = new SecretKeySpec(decodedKey, 0, decodedKey.length, "AES");
// AES defaults to AES/ECB/PKCS5Padding in Java 7
Cipher aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.DECRYPT_MODE, originalKey);
byte[] bytePlainText = aesCipher.doFinal(Base64.getDecoder().decode(encryptedText));
return new String(bytePlainText);
}

使用 RSA 私钥加密 AES 密钥

private static byte[] encryptAESKey(String plainAESKey, Key publicKey ) throws Exception {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
return Base64.getEncoder().encode(cipher.doFinal(plainAESKey.getBytes()));
}

使用 RSA 公钥解密 AES 密钥

private static String decryptAESKey(byte[] encryptedAESKey, Key privateKey) throws Exception {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, privateKey);
return new String(cipher.doFinal(Base64.getDecoder().decode(encryptedAESKey)));
}

获取公共和私有 .jks 格式密钥

public static Key getPrivate(String filename) throws Exception {
String password = "123456";
FileInputStream is = new FileInputStream(filename);
KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(is, password.toCharArray());
String alias = "rib_pub_priv_ob";
Key key = keystore.getKey(alias, password.toCharArray());        
return key;
}
// https://docs.oracle.com/javase/8/docs/api/java/security/spec/X509EncodedKeySpec.html
public static Key getPublic(String filename) throws Exception {
String password = "123456";
FileInputStream is = new FileInputStream(filename);
KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(is, password.toCharArray());
String alias = "tmsx_pub_priv_ob";
Key key = keystore.getKey(alias, password.toCharArray());        
return key;
}

}

以下是输出

Private key success
Private key :sun.security.rsa.RSAPrivateCrtKeyImpl@ffd2dcac
Public key success
Public key :sun.security.rsa.RSAPrivateCrtKeyImpl@fff19d78
Secret Key XsZue3ATt4OAQFP5C4sa8Q==
Encrypted text mjynBmIDhsj9L3jhFmzb4CFaJr+i5k2B1luuTdg0ls3NoAvI3wLfeU54Sxo7IDBrqH3i3F3RNM4DDPhWdbtEMNQ+27EcQOugidB2BcTFigzIImNohZOVjBi+qrPC7KWGLf9JWlJHUsoUz+oKiuAJGjitrrIMg/qQN7He87hH6hxfNZ7vceZV2N6HihYsQ4R1S6YFRUDVBwuG+IjvEyzihkw4mmlmjq4FIspXmaYuxYE/6urevUD/dY7HSLVrVRst83VRKnqDrzf32RolGsM12Ebyk0XJGGOYHV/OWfYExkaQdfUaEVMhU3h/tTmSoVJHEHTf1YdMxv5x/HZd2aXoYw==
Encrypted AES key with RSA [B@5f150435
Exception in thread "main" javax.crypto.BadPaddingException: Decryption error
at sun.security.rsa.RSAPadding.unpadV15(RSAPadding.java:380)
at sun.security.rsa.RSAPadding.unpad(RSAPadding.java:291)
at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:363)
at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at demo123.AESwithRSA.decryptAESKey(AESwithRSA.java:135)
at demo123.AESwithRSA.main(AESwithRSA.java:60)

Answer 1

该错误是由加载getPublic私钥而不是公钥引起的。这可以在输出中轻松看到：对于这两个键，将显示sun.security.rsa.RSAPrivateCrtKeyImpl类型的对象，而公钥实际上应该是sun.security.rsa.RSAPublicKeyImpl类型。要在getPublic中加载公钥，请替换该行

Key key = keystore.getKey(alias, password.toCharArray());    

由

Key key = keystore.getCertificate(alias).getPublicKey(); 

参见[1][2]。通过此修复程序，代码可以在我的机器上运行。

更新：在当前代码中，Base64 编码的 AES 密钥(来自getSecretAESKey年(使用 RSA 加密，然后此密钥再次使用 Base64 编码(encryptAESKey年(。这种双 Base64 编码实际上不是必需的，因为使用 RSA 加密原始AES 密钥就足够了，因为每个 Base64 编码都有 33% 的开销。