/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Boris Kuznetsov
* @version $Revision$
*/
package org.apache.harmony.security.utils;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.security.GeneralSecurityException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.Principal;
import java.security.Signature;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import javax.security.auth.x500.X500Principal;
import org.apache.harmony.security.asn1.BerInputStream;
import org.apache.harmony.security.pkcs7.ContentInfo;
import org.apache.harmony.security.pkcs7.SignedData;
import org.apache.harmony.security.pkcs7.SignerInfo;
import org.apache.harmony.security.provider.cert.X509CertImpl;
import org.apache.harmony.security.x501.AttributeTypeAndValue;
import org.apache.harmony.xnet.provider.jsse.OpenSSLSignature;
public class JarUtils {
// as defined in PKCS #9: Selected Attribute Types:
// http://www.ietf.org/rfc/rfc2985.txt
private static final int[] MESSAGE_DIGEST_OID =
new int[] {1, 2, 840, 113549, 1, 9, 4};
/**
* This method handle all the work with PKCS7, ASN1 encoding, signature verifying,
* and certification path building.
* See also PKCS #7: Cryptographic Message Syntax Standard:
* http://www.ietf.org/rfc/rfc2315.txt
* @param signature - the input stream of signature file to be verified
* @param signatureBlock - the input stream of corresponding signature block file
* @return array of certificates used to verify the signature file
* @throws IOException - if some errors occurs during reading from the stream
* @throws GeneralSecurityException - if signature verification process fails
*/
public static Certificate[] verifySignature(InputStream signature, InputStream
signatureBlock) throws IOException, GeneralSecurityException {
BerInputStream bis = new BerInputStream(signatureBlock);
ContentInfo info = (ContentInfo)ContentInfo.ASN1.decode(bis);
SignedData signedData = info.getSignedData();
if (signedData == null) {
throw new IOException("No SignedData found");
}
Collection<org.apache.harmony.security.x509.Certificate> encCerts
= signedData.getCertificates();
if (encCerts.isEmpty()) {
return null;
}
X509Certificate[] certs = new X509Certificate[encCerts.size()];
int i = 0;
for (org.apache.harmony.security.x509.Certificate encCert : encCerts) {
certs[i++] = new X509CertImpl(encCert);
}
List<SignerInfo> sigInfos = signedData.getSignerInfos();
SignerInfo sigInfo;
if (!sigInfos.isEmpty()) {
sigInfo = sigInfos.get(0);
} else {
return null;
}
// Issuer
X500Principal issuer = sigInfo.getIssuer();
// Certificate serial number
BigInteger snum = sigInfo.getSerialNumber();
// Locate the certificate
int issuerSertIndex = 0;
for (i = 0; i < certs.length; i++) {
if (issuer.equals(certs[i].getIssuerDN()) &&
snum.equals(certs[i].getSerialNumber())) {
issuerSertIndex = i;
break;
}
}
if (i == certs.length) { // No issuer certificate found
return null;
}
if (certs[issuerSertIndex].hasUnsupportedCriticalExtension()) {
throw new SecurityException("Can not recognize a critical extension");
}
// Get Signature instance
Signature sig = null;
String da = sigInfo.getDigestAlgorithm();
String dea = sigInfo.getDigestEncryptionAlgorithm();
String alg = null;
if (da != null && dea != null) {
alg = da + "with" + dea;
try {
sig = OpenSSLSignature.getInstance(alg);
} catch (NoSuchAlgorithmException e) {}
}
if (sig == null) {
alg = da;
if (alg == null) {
return null;
}
try {
sig = OpenSSLSignature.getInstance(alg);
} catch (NoSuchAlgorithmException e) {
return null;
}
}
sig.initVerify(certs[issuerSertIndex]);
// If the authenticatedAttributes field of SignerInfo contains more than zero attributes,
// compute the message digest on the ASN.1 DER encoding of the Attributes value.
// Otherwise, compute the message digest on the data.
List<AttributeTypeAndValue> atr = sigInfo.getAuthenticatedAttributes();
byte[] sfBytes = new byte[signature.available()];
signature.read(sfBytes);
if (atr == null) {
sig.update(sfBytes);
} else {
sig.update(sigInfo.getEncodedAuthenticatedAttributes());
// If the authenticatedAttributes field contains the message-digest attribute,
// verify that it equals the computed digest of the signature file
byte[] existingDigest = null;
for (AttributeTypeAndValue a : atr) {
if (Arrays.equals(a.getType().getOid(), MESSAGE_DIGEST_OID)) {
//TODO value existingDigest = a.AttributeValue;
}
}
if (existingDigest != null) {
MessageDigest md = MessageDigest.getInstance(sigInfo.getDigestAlgorithm());
byte[] computedDigest = md.digest(sfBytes);
if (!Arrays.equals(existingDigest, computedDigest)) {
throw new SecurityException("Incorrect MD");
}
}
}
if (!sig.verify(sigInfo.getEncryptedDigest())) {
throw new SecurityException("Incorrect signature");
}
return createChain(certs[issuerSertIndex], certs);
}
private static X509Certificate[] createChain(X509Certificate signer, X509Certificate[] candidates) {
LinkedList chain = new LinkedList();
chain.add(0, signer);
// Signer is self-signed
if (signer.getSubjectDN().equals(signer.getIssuerDN())){
return (X509Certificate[])chain.toArray(new X509Certificate[1]);
}
Principal issuer = signer.getIssuerDN();
X509Certificate issuerCert;
int count = 1;
while (true) {
issuerCert = findCert(issuer, candidates);
if( issuerCert == null) {
break;
}
chain.add(issuerCert);
count++;
if (issuerCert.getSubjectDN().equals(issuerCert.getIssuerDN())) {
break;
}
issuer = issuerCert.getIssuerDN();
}
return (X509Certificate[])chain.toArray(new X509Certificate[count]);
}
private static X509Certificate findCert(Principal issuer, X509Certificate[] candidates) {
for (int i = 0; i < candidates.length; i++) {
if (issuer.equals(candidates[i].getSubjectDN())) {
return candidates[i];
}
}
return null;
}
}