java - 在 Java 中使用 RSA 公钥加密数据并在 Crypto++ 中解密

Question

我正在尝试使用 Java 中的 RSA 公钥加密数据并使用 Crypto++ 对其进行解密。它会导致错误:

"RSA/EME-PKCS1-v1_5: ciphertext length of 24 doesn't match the required length of 128 for this key"

我做错了什么？

Java:

String cipher = Encryption.encryptStrRSA(txt, pubKeyk);

public static String encryptStrRSA(String str, PublicKey pubKey)
    throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
    IllegalBlockSizeException, BadPaddingException, NoSuchProviderException {

    Cipher cipher = Cipher.getInstance("RSA/NONE/PKCS1Padding", "BC");
    cipher.init(Cipher.ENCRYPT_MODE, pubKey);

    byte[] encryptedAesKey = cipher.doFinal(str.getBytes());
    String cipherStr = new String(encryptedAesKey);

    System.out.println(cipherStr);
    return cipherStr;
}

public static PublicKey strToPublicKey(String key64) throws GeneralSecurityException {
    byte[] data = Base64.getDecoder().decode(key64);
    X509EncodedKeySpec spec = new X509EncodedKeySpec(data);
    KeyFactory fact = KeyFactory.getInstance("RSA");
    return fact.generatePublic(spec);
}

public static String publicKeyToStr(PublicKey publ) throws GeneralSecurityException {
    KeyFactory fact = KeyFactory.getInstance("RSA");
    X509EncodedKeySpec spec = fact.getKeySpec(publ, X509EncodedKeySpec.class);
    return Base64.getEncoder().encode(spec.getEncoded()).toString();
}

加密++:

using namespace CryptoPP;

RSAES_PKCS1v15_Decryptor priv(privString);
StringSource( cipher, cipherSize, true, new 
Base64Decoder( new PK_DecryptorFilter(randPool, priv, new StringSink(sdata))));

Answer 1

使用 String 实例来保存二进制数据是危险的——您应该改用 byte[]。

此外，在 java 代码中没有对生成的密文进行 Base64 包装，但在 C++ 代码中它是从 Base64 中解包的。

修改您的代码以返回 byte[] 并使用 Base64 对结果进行编码:

public static byte[] encryptRSA(String str, PublicKey pubKey) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, NoSuchProviderException {
    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", "BC");
    cipher.init(Cipher.ENCRYPT_MODE, pubKey);
    return cipher.doFinal(str.getBytes());
}

String cipher = Base64.getEncoder().encodeToString(Encryption.encryptRSA("0123456789ABCDEF", pubKeyk));

然后您可以像以前一样在 Crypto++ 中解密。

祝你好运!