java - java和android的加密区别

Question

我在我的 java 应用程序中使用带有公钥的 RSA 加密将数据发送到服务器。当我使用 java 执行此操作时一切正常，但是当我尝试使用 android 执行相同操作时，我在服务器中收到以下错误:

java.security.InvalidKeyException: Illegal key size or default parameters

这是我在 android 和 java 上加密数据的代码:

import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import java.io.*;
import java.security.GeneralSecurityException;
import java.security.Key;
import java.security.SecureRandom;

public class Encryption {
    private static String base64Encode(byte[] bytes) {
        return Base64.encodeBase64String(bytes);
    }

    private static void crypt(InputStream in, OutputStream out, Cipher cipher) throws IOException, GeneralSecurityException {
        int blockSize = cipher.getBlockSize();
        int outputSize = cipher.getOutputSize(blockSize);
        byte[] inBytes = new byte[blockSize];
        byte[] outBytes = new byte[outputSize];

        int inLength = 0;
        boolean more = true;
        while (more) {
            inLength = in.read(inBytes);
            if (inLength == blockSize) {
                int outLength = cipher.update(inBytes, 0, blockSize, outBytes);
                out.write(outBytes, 0, outLength);
            } else more = false;
        }
        if (inLength > 0) outBytes = cipher.doFinal(inBytes, 0, inLength);
        else outBytes = cipher.doFinal();

        out.write(outBytes);
    }

    public static String encryptWithPublicKey(String property) {
        String result = null;

        KeyGenerator keygen;
        SecureRandom random;
        Key publicKey;
        SecretKey key;
        Cipher cipher;

        ObjectInputStream keyIn = null;
        ByteArrayOutputStream baos = null;
        DataOutputStream out = null;
        InputStream in = null;

        try {
            keygen = KeyGenerator.getInstance("AES");
            random = new SecureRandom();
            keygen.init(random);
            key = keygen.generateKey();

            keyIn = new ObjectInputStream(new FileInputStream("public.key"));
            publicKey = (Key) keyIn.readObject();

            cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            cipher.init(Cipher.WRAP_MODE, publicKey);
            byte[] wrappedKey = cipher.wrap(key);

            baos = new ByteArrayOutputStream();

            out = new DataOutputStream(baos);
            out.writeInt(wrappedKey.length);
            out.write(wrappedKey);

            in = new ByteArrayInputStream(property.getBytes("UTF-8"));
            cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, key);
            crypt(in, out, cipher);

            result = base64Encode(baos.toByteArray());
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            Util.close(baos);
            Util.close(out);
            Util.close(in);
            Util.close(keyIn);
        }

        return result;
    }
}

当我从java代码使用encryptWithPublicKey时结果很好，但当我从android使用它时出现错误!这两个系统之间有什么区别？

Answer 1

发生这种情况的原因可能是您没有为 Cipher 对象指定完整的 algorithm/mode/padding 选项。

例如，将“RSA”更改为“RSA/ECB/PKCS1Padding”。并将“AES”更改为“AES/CBC/PKCS5Padding”。或者任何合适的值。

原因:不同的加密提供商对于填充和模式有不同的默认值。如果您只指定算法，则您将依赖默认值，而不同系统之间可能不兼容。