org.apache.james.jmap.crypto.JamesSignatureHandler Maven / Gradle / Ivy

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package org.apache.james.jmap.crypto;

import java.io.InputStream;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.SignatureException;
import java.security.cert.Certificate;
import java.util.Base64;
import java.util.Optional;

import javax.inject.Inject;

import org.apache.james.filesystem.api.FileSystem;
import org.apache.james.jmap.JMAPConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;

public class JamesSignatureHandler implements SignatureHandler {

    private static final Logger LOGGER = LoggerFactory.getLogger(JamesSignatureHandler.class);

    public static final String ALIAS = "james";
    public static final String ALGORITHM = "SHA1withRSA";
    public static final String JKS = "JKS";
    
    private final FileSystem fileSystem;
    private final JMAPConfiguration jmapConfiguration;

    private PrivateKey privateKey;
    private PublicKey publicKey;


    @Inject
    @VisibleForTesting JamesSignatureHandler(FileSystem fileSystem, JMAPConfiguration jmapConfiguration) {
        this.fileSystem = fileSystem;
        this.jmapConfiguration = jmapConfiguration;
    }

    @Override
    public void init() throws Exception {
        KeyStore keystore = KeyStore.getInstance(JKS);
        InputStream fis = fileSystem.getResource(jmapConfiguration.getKeystore());
        char[] secret = jmapConfiguration.getSecret().toCharArray();
        keystore.load(fis, secret);
        Certificate aliasCertificate = Optional
                .ofNullable(keystore.getCertificate(ALIAS))
                .orElseThrow(() -> new KeyStoreException("Alias '" + ALIAS + "' keystore can't be found"));

        publicKey = aliasCertificate.getPublicKey();
        Key key = keystore.getKey(ALIAS, secret);
        if (! (key instanceof PrivateKey)) {
            throw new KeyStoreException("Provided key is not a PrivateKey");
        }
        privateKey = (PrivateKey) key;
    }

    @Override
    public String sign(String source) {
        Preconditions.checkNotNull(source);
        try {
            Signature javaSignature = Signature.getInstance(ALGORITHM);
            javaSignature.initSign(privateKey);
            javaSignature.update(source.getBytes());
            return Base64.getEncoder().encodeToString(javaSignature.sign());
        } catch (NoSuchAlgorithmException | InvalidKeyException | SignatureException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public boolean verify(String source, String signature) {
        Preconditions.checkNotNull(source);
        Preconditions.checkNotNull(signature);
        try {
            Signature javaSignature = Signature.getInstance(ALGORITHM);
            javaSignature.initVerify(publicKey);
            javaSignature.update(source.getBytes());
            return javaSignature.verify(Base64.getDecoder().decode(signature));
        } catch (NoSuchAlgorithmException | InvalidKeyException e) {
            throw new RuntimeException(e);
        } catch (SignatureException e) {
            LOGGER.warn("Attempt to use a malformed signature '{}' for source '{}'", signature, source, e);
            return false;
        }
    }
}