jdnssec-tools/src/main/java/com/verisignlabs/dnssec/security/DnsSecVerifier.java

330 lines
8.6 KiB
Java

// $Id$
//
// Copyright (C) 2001-2003 VeriSign, Inc.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA
package com.verisignlabs.dnssec.security;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Logger;
import org.xbill.DNS.*;
/**
* A class for performing basic DNSSEC verification. The DNSJAVA package
* contains a similar class. This differs (for the moment, anyway) by allowing
* timing "fudge" factors and logging more specifically why an RRset did not
* validate.
*
* @author David Blacka (original)
* @author $Author$
* @version $Revision$
*/
public class DnsSecVerifier
{
private class TrustedKeyStore
{
// for now, this is implemented as a hash table of lists of
// DnsKeyPair objects (obviously, all of them will not have
// private keys).
private HashMap<String, List<DnsKeyPair>> mKeyMap;
public TrustedKeyStore()
{
mKeyMap = new HashMap<String, List<DnsKeyPair>>();
}
public void add(DnsKeyPair pair)
{
String n = pair.getDNSKEYName().toString().toLowerCase();
List<DnsKeyPair> l = mKeyMap.get(n);
if (l == null)
{
l = new ArrayList<DnsKeyPair>();
mKeyMap.put(n, l);
}
l.add(pair);
}
public void add(DNSKEYRecord keyrec)
{
DnsKeyPair pair = new DnsKeyPair(keyrec, (PrivateKey) null);
add(pair);
}
public void add(Name name, int algorithm, PublicKey key)
{
DnsKeyPair pair = new DnsKeyPair(name, algorithm, key, null);
add(pair);
}
public DnsKeyPair find(Name name, int algorithm, int keyid)
{
String n = name.toString().toLowerCase();
List<DnsKeyPair> l = mKeyMap.get(n);
if (l == null) return null;
// FIXME: this algorithm assumes that name+alg+footprint is
// unique, which isn't necessarily true.
for (DnsKeyPair p : l)
{
if (p.getDNSKEYAlgorithm() == algorithm && p.getDNSKEYFootprint() == keyid)
{
return p;
}
}
return null;
}
}
private TrustedKeyStore mKeyStore;
private int mStartFudge = 0;
private int mExpireFudge = 0;
private boolean mVerifyAllSigs = false;
private boolean mIgnoreTime = false;
private Logger log;
public DnsSecVerifier()
{
log = Logger.getLogger(this.getClass().toString());
mKeyStore = new TrustedKeyStore();
}
public void addTrustedKey(DNSKEYRecord keyrec)
{
mKeyStore.add(keyrec);
}
public void addTrustedKey(DnsKeyPair pair)
{
mKeyStore.add(pair);
}
public void addTrustedKey(Name name, int algorithm, PublicKey key)
{
mKeyStore.add(name, algorithm, key);
}
public void addTrustedKey(Name name, PublicKey key)
{
mKeyStore.add(name, 0, key);
}
public void setExpireFudge(int fudge)
{
mExpireFudge = fudge;
}
public void setStartFudge(int fudge)
{
mStartFudge = fudge;
}
public void setVerifyAllSigs(boolean v)
{
mVerifyAllSigs = v;
}
public void setIgnoreTime(boolean v)
{
mIgnoreTime = v;
}
private DnsKeyPair findKey(Name name, int algorithm, int footprint)
{
return mKeyStore.find(name, algorithm, footprint);
}
private boolean validateSignature(RRset rrset, RRSIGRecord sigrec, List<String> reasons)
{
if (rrset == null || sigrec == null) return false;
if (!rrset.getName().equals(sigrec.getName()))
{
log.fine("Signature name does not match RRset name");
if (reasons != null) reasons.add("Signature name does not match RRset name");
return false;
}
if (rrset.getType() != sigrec.getTypeCovered())
{
log.fine("Signature type does not match RRset type");
if (reasons != null) reasons.add("Signature type does not match RRset type");
}
if (mIgnoreTime) return true;
Date now = new Date();
Date start = sigrec.getTimeSigned();
Date expire = sigrec.getExpire();
if (mStartFudge >= 0)
{
if (mStartFudge > 0)
{
start = new Date(start.getTime() - ((long) mStartFudge * 1000));
}
if (now.before(start))
{
log.fine("Signature is not yet valid");
if (reasons != null) reasons.add("Signature not yet valid");
return false;
}
}
if (mExpireFudge >= 0)
{
if (mExpireFudge > 0)
{
expire = new Date(expire.getTime() + ((long) mExpireFudge * 1000));
}
if (now.after(expire))
{
log.fine("Signature has expired (now = " + now + ", sig expires = " + expire);
if (reasons != null) reasons.add("Signature has expired.");
return false;
}
}
if (rrset.getTTL() > sigrec.getOrigTTL())
{
log.fine("RRset's TTL is greater than the Signature's orignal TTL");
if (reasons != null) reasons.add("RRset TTL greater than RRSIG origTTL");
return false;
}
return true;
}
public boolean verifySignature(RRset rrset, RRSIGRecord sigrec)
{
return verifySignature(rrset, sigrec, null);
}
/**
* Verify an RRset against a particular signature.
*
* @return true if the signature verified, false if it did
* not verify (for any reason, including not finding the DNSKEY.)
*/
public boolean verifySignature(RRset rrset, RRSIGRecord sigrec, List<String> reasons)
{
boolean result = validateSignature(rrset, sigrec, reasons);
if (!result) return result;
DnsKeyPair keypair = findKey(sigrec.getSigner(), sigrec.getAlgorithm(),
sigrec.getFootprint());
if (keypair == null)
{
if (reasons != null) reasons.add("Could not find matching trusted key");
log.fine("could not find matching trusted key");
return false;
}
try
{
byte[] data = SignUtils.generateSigData(rrset, sigrec);
DnsKeyAlgorithm algs = DnsKeyAlgorithm.getInstance();
Signature signer = keypair.getVerifier();
signer.update(data);
byte[] sig = sigrec.getSignature();
if (algs.baseType(sigrec.getAlgorithm()) == DnsKeyAlgorithm.DSA)
{
sig = SignUtils.convertDSASignature(sig);
}
if (sigrec.getAlgorithm() == DNSSEC.Algorithm.ECDSAP256SHA256 ||
sigrec.getAlgorithm() == DNSSEC.Algorithm.ECDSAP384SHA384)
{
sig = SignUtils.convertECDSASignature(sig);
}
if (!signer.verify(sig))
{
if (reasons != null) reasons.add("Signature failed to verify cryptographically");
log.fine("Signature failed to verify cryptographically");
return false;
}
return true;
}
catch (IOException e)
{
log.severe("I/O error: " + e);
}
catch (GeneralSecurityException e)
{
log.severe("Security error: " + e);
}
if (reasons != null) reasons.add("Signature failed to verify due to exception");
log.fine("Signature failed to verify due to exception");
return false;
}
/**
* Verifies an RRset. This routine does not modify the RRset.
*
* @return true if the set verified, false if it did not.
*/
public boolean verify(RRset rrset)
{
boolean result = mVerifyAllSigs ? true : false;
Iterator i = rrset.sigs();
if (!i.hasNext())
{
log.fine("RRset failed to verify due to lack of signatures");
return false;
}
while (i.hasNext())
{
RRSIGRecord sigrec = (RRSIGRecord) i.next();
boolean res = verifySignature(rrset, sigrec);
// If not requiring all signature to validate, then any successful validation is sufficient.
if (!mVerifyAllSigs && res) return res;
// Otherwise, note if a signature failed to validate.
if (mVerifyAllSigs && !res)
{
result = res;
}
}
return result;
}
}