我在下面有一些代码,它应该使用 SHA1 创建消息的散列,打印散列,使用 RSA 算法加密消息,打印出加密的消息,然后解密消息并再次打印散列。第一个和第三个打印消息应该匹配,因为它们都是原始消息的未加密哈希,但在我的代码中它们不匹配 - 谁能告诉我为什么?谢谢。我的代码如下:
String input = "input message test";
MessageDigest hash = MessageDigest.getInstance("SHA1");
hash.update(Utils.toByteArray(input));
System.out.println("digest : " +hash.digest());
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
SecureRandom random = new SecureRandom();
KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
generator.initialize(512, random);
KeyPair pair = generator.generateKeyPair();
Key pubKey = pair.getPublic();
Key privKey = pair.getPrivate();
cipher.init(Cipher.ENCRYPT_MODE, privKey);
byte[] ciphertext = cipher.doFinal(hash.digest());
System.out.println("cipher: " + ciphertext);
cipher.init(Cipher.DECRYPT_MODE, pubKey);
byte[] plaintext = cipher.doFinal(ciphertext);
System.out.println("plaintext : " + plaintext);
更新:我已经有了这个,我刚刚删除了它,因为它在第二个文件中。我的方法是:
public static String toHex(byte[] data, int length) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i != length; i++) {
int v = data[i] & 0xff;
buf.append(digits.charAt(v >> 4));
buf.append(digits.charAt(v & 0xf));
}
return buf.toString();
}
但这会返回:
digest : b2cad21e87dbd57f1a1928e4013b56fb553bb82a
cipher: 502cffa545bda39f677b72f677f1a6a4308a329747a8f4de9b0d1ffd83fcec10c5b41a218201e204c7949b45a8119eb42e6ab5dc0c97f97b6d59600632d2b2ad
plaintext : da39a3ee5e6b4b0d3255bfef95601890afd80709