如何使用公钥验证ECDSA？

Question

我有以下几种方法来生成密钥和对密码消息进行签名。

public void generateKeys() {
try {
  keyStore = KeyStore.getInstance(KEYSTORE_NAME);
  keyStore.load(null);

  if (!keyStore.containsAlias(KEY_NAME)) {
    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KeyProperties.KEY_ALGORITHM_EC, KEYSTORE_NAME);
    keyPairGenerator.initialize(
        new KeyGenParameterSpec.Builder(KEY_NAME,
                                        KeyProperties.PURPOSE_SIGN)
            .setDigests(KeyProperties.DIGEST_SHA256)
            .setAlgorithmParameterSpec(new ECGenParameterSpec("secp256r1"))
            // Require the user to authenticate with a fingerprint to authorize
            // every use of the private key
            .setUserAuthenticationRequired(true)
            .build());
    keyPairGenerator.generateKeyPair();
  }

  loadKeys();
} catch (NoSuchAlgorithmException e) {
  e.printStackTrace();
} catch (NoSuchProviderException e) {
  e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
  e.printStackTrace();
} catch (CertificateException e) {
  e.printStackTrace();
} catch (KeyStoreException e) {
  e.printStackTrace();
} catch (IOException e) {
  e.printStackTrace();
}

}

public BiometricPrompt.CryptoObject getCryptoObject() {
cryptoObject = new BiometricPrompt.CryptoObject(signature);
return cryptoObject;
}

private void loadKeys() {
try {
  keyStore = KeyStore.getInstance(KEYSTORE_NAME);
  keyStore.load(null);
  if (keyStore.containsAlias(KEY_NAME)) {
    publicKey = keyStore.getCertificate(KEY_NAME).getPublicKey();
    privateKey = (PrivateKey) keyStore.getKey(KEY_NAME, null);
    signature = Signature.getInstance(Constants.SIGNATURE);
    signature.initSign(privateKey);
  }
} catch (IOException e) {
  e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
  e.printStackTrace();
} catch (CertificateException e) {
  e.printStackTrace();
} catch (KeyStoreException e) {
  e.printStackTrace();
} catch (UnrecoverableKeyException e) {
  e.printStackTrace();
} catch (InvalidKeyException e) {
  e.printStackTrace();
}
}

public String sign(String inputStr) {
try {
  Signature signature = cryptoObject.getSignature();
  signature.update(inputStr.getBytes());
  byte[] signedBytes = signature.sign();
  String result = HexManager.bytesToHex(signedBytes);
  Log.d("TAG", result);
  return result;
} catch (SignatureException e) {
  e.printStackTrace();
}
return null;

}

之后，我将签名的密码保存在“共享首选项”中。稍后，我要使用已用指纹验证的新密码来验证保存的密码。

这是我的验证方法：

public boolean verify(String inputStr, String savedStr) {
try {
  Signature signature = cryptoObject.getSignature();
  signature.initVerify(publicKey);
  signature.update(inputStr.getBytes());
  boolean isVerified = signature.verify(savedStr.getBytes());
  return isVerified;
} catch (InvalidKeyException e) {
  e.printStackTrace();
} catch (SignatureException e) {
  e.printStackTrace();
}
return false;
}

但是它总是返回false。

有人知道为什么吗？

Answer 1

在您的sign()方法中，您似乎返回了从Hex方法获得的byte[]的{​​{1}}。如果这是您要另存为signature.sign()的内容。然后，应更改验证方法以将savedStr编码的字符串转换为Hex。如果存在byte[]（或等效值），可以将HexManager.hexToBytes()转换为savedStr。

byte[] savedStrBytes