luni/src/main/java/org/apache/harmony/security/utils/JarUtils.java - platform/libcore - Git at Google

 /*
  *  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.ByteArrayInputStream;
 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.CertificateEncodingException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import javax.security.auth.x500.X500Principal;

 import org.apache.harmony.security.asn1.ASN1OctetString;
 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.x501.AttributeTypeAndValue;

 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()];
         CertificateFactory cf = CertificateFactory.getInstance("X.509");
         int i = 0;
         for (org.apache.harmony.security.x509.Certificate encCert : encCerts) {
             final byte[] encoded = encCert.getEncoded();
             final InputStream is = new ByteArrayInputStream(encoded);
             certs[i++] = new VerbatimX509Certificate((X509Certificate) cf.generateCertificate(is),
                     encoded);
         }

         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
         final String daOid = sigInfo.getDigestAlgorithm();
         final String daName = sigInfo.getDigestAlgorithmName();
         final String deaOid = sigInfo.getDigestEncryptionAlgorithm();

         String alg = null;
         Signature sig = null;

         if (deaOid != null) {
             alg = deaOid;
             try {
                 sig = Signature.getInstance(alg);
             } catch (NoSuchAlgorithmException e) {
             }

             final String deaName = sigInfo.getDigestEncryptionAlgorithmName();
             if (sig == null && deaName != null) {
                 alg = deaName;
                 try {
                     sig = Signature.getInstance(alg);
                 } catch (NoSuchAlgorithmException e) {
                 }
             }
         }

         if (sig == null && daOid != null && deaOid != null) {
             alg = daOid + "with" + deaOid;
             try {
                 sig = Signature.getInstance(alg);
             } catch (NoSuchAlgorithmException e) {
             }

             // Try to convert to names instead of OID.
             if (sig == null) {
                 final String deaName = sigInfo.getDigestEncryptionAlgorithmName();
                 alg = daName + "with" + deaName;
                 try {
                     sig = Signature.getInstance(alg);
                 } catch (NoSuchAlgorithmException e) {
                 }
             }
         }

         // We couldn't find a valid Signature type.
         if (sig == null) {
             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)) {
                     if (existingDigest != null) {
                         throw new SecurityException("Too many MessageDigest attributes");
                     }
                     Collection<?> entries = a.getValue().getValues(ASN1OctetString.getInstance());
                     if (entries.size() != 1) {
                         throw new SecurityException("Too many values for MessageDigest attribute");
                     }
                     existingDigest = (byte[]) entries.iterator().next();
                 }
             }

             // RFC 3852 section 9.2: it authAttrs is present, it must have a
             // message digest entry.
             if (existingDigest == null) {
                 throw new SecurityException("Missing MessageDigest in Authenticated Attributes");
             }

             MessageDigest md = null;
             if (daOid != null) {
                 md = MessageDigest.getInstance(daOid);
             }
             if (md == null && daName != null) {
                 md = MessageDigest.getInstance(daName);
             }
             if (md == null) {
                 return null;
             }

             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) {
         Principal issuer = signer.getIssuerDN();

         // Signer is self-signed
         if (signer.getSubjectDN().equals(issuer)) {
             return new X509Certificate[] { signer };
         }

         ArrayList<X509Certificate> chain = new ArrayList<X509Certificate>(candidates.length + 1);
         chain.add(0, signer);

         X509Certificate issuerCert;
         int count = 1;
         while (true) {
             issuerCert = findCert(issuer, candidates);
             if (issuerCert == null) {
                 break;
             }
             chain.add(issuerCert);
             count++;
             issuer = issuerCert.getIssuerDN();
             if (issuerCert.getSubjectDN().equals(issuer)) {
                 break;
             }
         }
         return 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;
     }

     /**
      * For legacy reasons we need to return exactly the original encoded
      * certificate bytes, instead of letting the underlying implementation have
      * a shot at re-encoding the data.
      */
     private static class VerbatimX509Certificate extends WrappedX509Certificate {
         private byte[] encodedVerbatim;

         public VerbatimX509Certificate(X509Certificate wrapped, byte[] encodedVerbatim) {
             super(wrapped);
             this.encodedVerbatim = encodedVerbatim;
         }

         @Override
         public byte[] getEncoded() throws CertificateEncodingException {
             return encodedVerbatim;
         }
     }
 }
	/*
	* 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.ByteArrayInputStream;
	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.CertificateEncodingException;
	import java.security.cert.CertificateFactory;
	import java.security.cert.X509Certificate;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.List;
	import javax.security.auth.x500.X500Principal;

	import org.apache.harmony.security.asn1.ASN1OctetString;
	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.x501.AttributeTypeAndValue;

	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()];
	CertificateFactory cf = CertificateFactory.getInstance("X.509");
	int i = 0;
	for (org.apache.harmony.security.x509.Certificate encCert : encCerts) {
	final byte[] encoded = encCert.getEncoded();
	final InputStream is = new ByteArrayInputStream(encoded);
	certs[i++] = new VerbatimX509Certificate((X509Certificate) cf.generateCertificate(is),
	encoded);
	}

	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
	final String daOid = sigInfo.getDigestAlgorithm();
	final String daName = sigInfo.getDigestAlgorithmName();
	final String deaOid = sigInfo.getDigestEncryptionAlgorithm();

	String alg = null;
	Signature sig = null;

	if (deaOid != null) {
	alg = deaOid;
	try {
	sig = Signature.getInstance(alg);
	} catch (NoSuchAlgorithmException e) {
	}

	final String deaName = sigInfo.getDigestEncryptionAlgorithmName();
	if (sig == null && deaName != null) {
	alg = deaName;
	try {
	sig = Signature.getInstance(alg);
	} catch (NoSuchAlgorithmException e) {
	}
	}
	}

	if (sig == null && daOid != null && deaOid != null) {
	alg = daOid + "with" + deaOid;
	try {
	sig = Signature.getInstance(alg);
	} catch (NoSuchAlgorithmException e) {
	}

	// Try to convert to names instead of OID.
	if (sig == null) {
	final String deaName = sigInfo.getDigestEncryptionAlgorithmName();
	alg = daName + "with" + deaName;
	try {
	sig = Signature.getInstance(alg);
	} catch (NoSuchAlgorithmException e) {
	}
	}
	}

	// We couldn't find a valid Signature type.
	if (sig == null) {
	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)) {
	if (existingDigest != null) {
	throw new SecurityException("Too many MessageDigest attributes");
	}
	Collection<?> entries = a.getValue().getValues(ASN1OctetString.getInstance());
	if (entries.size() != 1) {
	throw new SecurityException("Too many values for MessageDigest attribute");
	}
	existingDigest = (byte[]) entries.iterator().next();
	}
	}

	// RFC 3852 section 9.2: it authAttrs is present, it must have a
	// message digest entry.
	if (existingDigest == null) {
	throw new SecurityException("Missing MessageDigest in Authenticated Attributes");
	}

	MessageDigest md = null;
	if (daOid != null) {
	md = MessageDigest.getInstance(daOid);
	}
	if (md == null && daName != null) {
	md = MessageDigest.getInstance(daName);
	}
	if (md == null) {
	return null;
	}

	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) {
	Principal issuer = signer.getIssuerDN();

	// Signer is self-signed
	if (signer.getSubjectDN().equals(issuer)) {
	return new X509Certificate[] { signer };
	}

	ArrayList<X509Certificate> chain = new ArrayList<X509Certificate>(candidates.length + 1);
	chain.add(0, signer);

	X509Certificate issuerCert;
	int count = 1;
	while (true) {
	issuerCert = findCert(issuer, candidates);
	if (issuerCert == null) {
	break;
	}
	chain.add(issuerCert);
	count++;
	issuer = issuerCert.getIssuerDN();
	if (issuerCert.getSubjectDN().equals(issuer)) {
	break;
	}
	}
	return 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;
	}

	/**
	* For legacy reasons we need to return exactly the original encoded
	* certificate bytes, instead of letting the underlying implementation have
	* a shot at re-encoding the data.
	*/
	private static class VerbatimX509Certificate extends WrappedX509Certificate {
	private byte[] encodedVerbatim;

	public VerbatimX509Certificate(X509Certificate wrapped, byte[] encodedVerbatim) {
	super(wrapped);
	this.encodedVerbatim = encodedVerbatim;
	}

	@Override
	public byte[] getEncoded() throws CertificateEncodingException {
	return encodedVerbatim;
	}
	}
	}