Question

我很难使用RSA进行签名和验证。以下是我使用的RSA课程的一部分。方法init()，privateKey()和publicKey()适用于encrypt()和decrypt()方法（此处未列出的最后两个），因此我假设我在内部犯了一些错误我的sign()方法。方法verify()尚未经过测试，因为签名失败，所以我无法继续前进。请看看......

我的RSA课程是：

class RSA
{
    private final static String ANDROID_KEY_STORE = "AndroidKeyStore";

    public final static int ANY_PURPOSE = KeyProperties.PURPOSE_ENCRYPT | 
            KeyProperties.PURPOSE_DECRYPT | KeyProperties.PURPOSE_SIGN | 
            KeyProperties.PURPOSE_VERIFY;

    public final static long CENTURY = (100 * 365) + 24;

    public enum KeySize
    {
        BIT_512  ( 512),
        BIT_768  ( 768),
        BIT_1024 (1024),
        BIT_2048 (2048),
        BIT_3072 (3072),
        BIT_4096 (4096);

        private int value;

        KeySize(int value)
        {
            this.value = value;
        }

        public int value()
        {
            return this.value;
        }
    }

    public enum SignatureAlgorithm
    {
        MD5WithRSA        ("MD5WithRSA"),
        SHA1WithRSA       ("SHA1WithRSA"),
        SHA1WithRSA_PSS   ("SHA1WithRSA/PSS"),
        SHA224WithRSA     ("SHA224WithRSA"),
        SHA224WithRSA_PSS ("SHA224WithRSA/PSS"),
        SHA256WithRSA     ("SHA256WithRSA"),
        SHA256WithRSA_PSS ("SHA256WithRSA/PSS"),
        SHA384WithRSA     ("SHA384WithRSA"),
        SHA384WithRSA_PSS ("SHA384WithRSA/PSS"),
        SHA512WithRSA     ("SHA512WithRSA"),
        SHA512WithRSA_PSS ("SHA512WithRSA/PSS");

        private String value;

        SignatureAlgorithm(String value)
        {
            this.value = value;
        }

        public String value()
        {
            return this.value;
        }
    }

    public static KeyPair init(final String alias, final RSA.KeySize keySize, 
                final long validityDays, final Boolean reset)
            throws KeyStoreException, NoSuchAlgorithmException, CertificateException, 
            IOException, NoSuchProviderException, InvalidAlgorithmParameterException
    {
        KeyStore keyStore = KeyStore.getInstance(ANDROID_KEY_STORE);
        keyStore.load(null);
        if (reset || (!keyStore.containsAlias(alias)))
        {
            final long now = java.lang.System.currentTimeMillis();
            KeyPairGenerator keyPairGenerator = KeyPairGenerator
                    .getInstance(KeyProperties.KEY_ALGORITHM_RSA, ANDROID_KEY_STORE);
            keyPairGenerator.initialize(
                    new KeyGenParameterSpec.Builder(alias, RSA.ANY_PURPOSE)
                    .setRandomizedEncryptionRequired(false)
                    .setDigests(
                            KeyProperties.DIGEST_NONE,   KeyProperties.DIGEST_MD5,
                            KeyProperties.DIGEST_SHA1,   KeyProperties.DIGEST_SHA224,
                            KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA384,
                            KeyProperties.DIGEST_SHA512)
                    .setKeySize(keySize.value())
                    .setEncryptionPaddings(
                            KeyProperties.ENCRYPTION_PADDING_NONE,
                            KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1,
                            KeyProperties.ENCRYPTION_PADDING_RSA_OAEP)
                    .setCertificateSubject(new X500Principal(
                            "CN=Android, O=Android Authority"))
                    .setCertificateSerialNumber(new BigInteger(256, new Random()))
                    .setCertificateNotBefore(new Date (now - (now % 1000L)))
                    .setCertificateNotAfter(new Date(((new Date(now - (now % 1000L)))
                            .getTime()) + (validityDays * 86400000L)))
                    .build());
            return keyPairGenerator.generateKeyPair();
        }
        else return null;
    }

    public static PublicKey publicKey(final String alias)
            throws KeyStoreException, NoSuchAlgorithmException, CertificateException, 
            IOException, UnrecoverableEntryException
    {
        KeyStore keyStore = KeyStore.getInstance(ANDROID_KEY_STORE);
        keyStore.load(null);
        return keyStore.getCertificate(alias).getPublicKey();
    }

    public static PrivateKey privateKey(final String alias)
            throws KeyStoreException, NoSuchAlgorithmException, CertificateException, 
            IOException, UnrecoverableEntryException
    {
        KeyStore keyStore = KeyStore.getInstance(ANDROID_KEY_STORE);
        keyStore.load(null);
        return (PrivateKey) keyStore.getKey(alias, null);
    }

    public static byte[] sign(final String message, final String alias, 
                final SignatureAlgorithm algorithm)
            throws KeyStoreException, NoSuchAlgorithmException, CertificateException, 
            IOException, UnrecoverableEntryException,
            InvalidKeyException, SignatureException
    {
        Signature instance = Signature.getInstance(algorithm.value());
        instance.initSign(privateKey(alias), new SecureRandom());
        instance.update(message.getBytes("UTF-8"));
        return instance.sign();
    }

    public static Boolean verify(final String message, final byte[] signature, 
                final String alias, final SignatureAlgorithm algorithm)
            throws KeyStoreException, NoSuchAlgorithmException, CertificateException, 
            IOException, UnrecoverableEntryException,
            InvalidKeyException, SignatureException
    {
        Signature instance = Signature.getInstance(algorithm.value());
        instance.initVerify(publicKey(alias));
        instance.update(message.getBytes("UTF-8"));
        return instance.verify(signature);
    }
}

我的Hex课程是：

class Hex
{
    private final static char[] hexArray = "0123456789ABCDEF".toCharArray();

    public static String bytesToHexString(final byte[] bytes)
    {
        char[] hexChars = new char[2 * bytes.length];
        for (int i = 0; i < bytes.length; i++)
        {
            int b = bytes[i] & 0xFF;
            hexChars[2 * i] = hexArray[b >>> 4];
            hexChars[2 * i + 1] = hexArray[b & 0x0F];
        }
        return new String(hexChars);
    }
}

我的测试代码是：

try
{
    RSA.init("RSA", RSA.KeySize.BIT_512, RSA.CENTURY, true);

    RSA.SignatureAlgorithm signatureAlgorithm = RSA.SignatureAlgorithm.SHA1WithRSA;

    byte[] x = RSA.sign("My message", "RSA", signatureAlgorithm);
    Log.d("RSA Test", "x: " + Hex.bytesToHexString(x));

    Boolean y = RSA.verify("My message", x, "RSA", signatureAlgorithm);
    Log.d("RSA Test", "y: " + (y? "True" : "False"));
}
catch (Exception e)
{
    Log.d("RSA Test", "ERROR: " + e.toString());
}

输出是：

错误：java.security.InvalidKeyException：密钥库操作失败

调试显示错误发生在我的RSA.sign()方法内，当它调用initSign()时。

我的代码有什么问题？

Answer 1

如果您使用RSA密钥进行签名，则必须在KeyGenParameterSpec中设置签名填充模式。你还没有这样做。例如，在init()方法中，您可以在.setEncryptionPaddings()之后添加以下行：

.setSignaturePaddings(KeyProperties.SIGNATURE_PADDING_RSA_PKCS1)

e.g。

keyPairGenerator.initialize(
                    new KeyGenParameterSpec.Builder(alias, RSA.ANY_PURPOSE)
                            .setRandomizedEncryptionRequired(false)
                            .setDigests(
                                    KeyProperties.DIGEST_NONE, KeyProperties.DIGEST_MD5,
                                    KeyProperties.DIGEST_SHA1, KeyProperties.DIGEST_SHA224,
                                    KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA384,
                                    KeyProperties.DIGEST_SHA512)
                            .setKeySize(keySize.value())
                            .setEncryptionPaddings(
                                    KeyProperties.ENCRYPTION_PADDING_NONE,
                                    KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1,
                                    KeyProperties.ENCRYPTION_PADDING_RSA_OAEP)
                            .setSignaturePaddings(KeyProperties.SIGNATURE_PADDING_RSA_PKCS1)
                            .setCertificateSubject(new X500Principal(
                                    "CN=Android, O=Android Authority"))
                            .setCertificateSerialNumber(new BigInteger(256, new Random()))
                            .setCertificateNotBefore(new Date(now - (now % 1000L)))
                            .setCertificateNotAfter(new Date(((new Date(now - (now % 1000L)))
                                    .getTime()) + (validityDays * 86400000L)))
                            .build());

其他支持的签名填充模式为SIGNATURE_PADDING_RSA_PSS。请注意，PSS签名和OAEP加密是用于签名和加密的更现代版本的RSA块格式。它们提供了更好的安全保障，并且应始终优先于其他模式，除非由于与现有代码库的互操作性问题而无法使用它们。

签名算法命名以＆＃34; PSS＆＃34;结尾，例如SHA224WithRSA_PSS显然仅用于PSS填充，而其他仅用于PKCS1填充。

密钥库操作因RSA签名和验证失败

1 个答案: