com.ksyun.ks3.service.encryption.internal.CryptoRuntime Maven / Gradle / Ivy

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package com.ksyun.ks3.service.encryption.internal;


import java.security.Provider;
import java.security.Security;

import javax.crypto.Cipher;

import org.apache.commons.logging.LogFactory;

public class CryptoRuntime {
    static final String BOUNCY_CASTLE_PROVIDER = "BC";
    private static final String BC_PROVIDER_FQCN = "org.bouncycastle.jce.provider.BouncyCastleProvider";
    
    public static boolean isBouncyCastleAvailable() {
        return Security.getProvider(BOUNCY_CASTLE_PROVIDER) != null;
    }

    public static void enableBouncyCastle() {
        try {
            @SuppressWarnings("unchecked")
            Class c = (Class)Class.forName(BC_PROVIDER_FQCN);
            Provider provider = c.newInstance();
            Security.addProvider(provider);
        } catch (Exception e) {
            LogFactory.getLog(CryptoRuntime.class).debug(
                    "Bouncy Castle not available", e);
        }
    }
    
    /**
     * Used only for unit test when the same class loader is used across
     * multiple unit tests.
     */
    static void recheck() {
        recheckAesGcmAvailablility();
        recheckRsaKeyWrapAvailablility();
    }
    
    public static boolean isAesGcmAvailable() { return AesGcm.isAvailable; }
    private static void recheckAesGcmAvailablility() { AesGcm.recheck(); }

    static boolean isRsaKeyWrapAvailable() {
        return RsaEcbOaepWithSHA256AndMGF1Padding.isAvailable;
    }

    private static void recheckRsaKeyWrapAvailablility() {
        RsaEcbOaepWithSHA256AndMGF1Padding.recheck();
    }

    private static final class AesGcm {
        static volatile boolean isAvailable = check();
        static boolean recheck() { return isAvailable = check(); }
        private static boolean check() {
            try {
                Cipher.getInstance(
                        ContentCryptoScheme.AES_GCM.getCipherAlgorithm(),
                        BOUNCY_CASTLE_PROVIDER);
                return true;
            } catch (Exception e) {
                return false;
            }
        }
    }
    private static final class RsaEcbOaepWithSHA256AndMGF1Padding {
        static volatile boolean isAvailable = check();
        static boolean recheck() { return isAvailable = check(); }
        private static boolean check() {
            try {
                Cipher.getInstance(S3KeyWrapScheme.RSA_ECB_OAEPWithSHA256AndMGF1Padding,
                        BOUNCY_CASTLE_PROVIDER);
                return true;
            } catch (Exception e) {
                return false;
            }
        }
    }
}