+/*
+ * $Id$
+ *
+ * Copyright (c) 2005 VeriSign, Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+package se.rfc.unbound;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.security.SignatureException;
+import java.security.interfaces.DSAParams;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Date;
+import java.util.Iterator;
+
+import org.xbill.DNS.DNSKEYRecord;
+import org.xbill.DNS.DNSOutput;
+import org.xbill.DNS.Name;
+import org.xbill.DNS.RRSIGRecord;
+import org.xbill.DNS.RRset;
+import org.xbill.DNS.Record;
+import org.xbill.DNS.utils.base64;
+
+/**
+ * This class contains a bunch of utility methods that are generally useful in
+ * signing and verifying rrsets.
+ *
+ * @author David Blacka (original)
+ * @author $Author$
+ * @version $Revision$
+ */
+
+public class SignUtils
+{
+
+ /**
+ * This class implements a basic comparitor for byte arrays. It is primarily
+ * useful for comparing RDATA portions of DNS records in doing DNSSEC
+ * canonical ordering.
+ *
+ * @author David Blacka (original)
+ */
+ public static class ByteArrayComparator implements Comparator
+ {
+ private int mOffset = 0;
+ private boolean mDebug = false;
+
+ public ByteArrayComparator()
+ {
+ }
+
+ public ByteArrayComparator(int offset, boolean debug)
+ {
+ mOffset = offset;
+ mDebug = debug;
+ }
+
+ public int compare(Object o1, Object o2) throws ClassCastException
+ {
+ byte[] b1 = (byte[]) o1;
+ byte[] b2 = (byte[]) o2;
+
+ for (int i = mOffset; i < b1.length && i < b2.length; i++)
+ {
+ if (b1[i] != b2[i])
+ {
+ if (mDebug)
+ {
+ System.out.println("offset " + i + " differs (this is "
+ + (i - mOffset) + " bytes in from our offset.)");
+ }
+ return (b1[i] & 0xFF) - (b2[i] & 0xFF);
+ }
+ }
+
+ return b1.length - b2.length;
+ }
+ }
+
+ // private static final int DSA_SIGNATURE_LENGTH = 20;
+ private static final int ASN1_INT = 0x02;
+ private static final int ASN1_SEQ = 0x30;
+
+ public static final int RR_NORMAL = 0;
+ public static final int RR_DELEGATION = 1;
+ public static final int RR_GLUE = 2;
+ public static final int RR_INVALID = 3;
+
+ /**
+ * Generate from some basic information a prototype SIG RR containing
+ * everything but the actual signature itself.
+ *
+ * @param rrset the RRset being signed.
+ * @param signer the name of the signing key
+ * @param alg the algorithm of the signing key
+ * @param keyid the keyid (or footprint) of the signing key
+ * @param start the SIG inception time.
+ * @param expire the SIG expiration time.
+ * @param sig_ttl the TTL of the resulting SIG record.
+ * @return a prototype signature based on the RRset and key information.
+ */
+ public static RRSIGRecord generatePreRRSIG(RRset rrset, Name signer,
+ int alg, int keyid, Date start, Date expire, long sig_ttl)
+ {
+ return new RRSIGRecord(rrset.getName(), rrset.getDClass(), sig_ttl, rrset
+ .getType(), alg, rrset.getTTL(), expire, start, keyid, signer, null);
+ }
+
+ /**
+ * Generate from some basic information a prototype SIG RR containing
+ * everything but the actual signature itself.
+ *
+ * @param rrset the RRset being signed.
+ * @param key the public KEY RR counterpart to the key being used to sign
+ * the RRset
+ * @param start the SIG inception time.
+ * @param expire the SIG expiration time.
+ * @param sig_ttl the TTL of the resulting SIG record.
+ * @return a prototype signature based on the RRset and key information.
+ */
+ public static RRSIGRecord generatePreRRSIG(RRset rrset, DNSKEYRecord key,
+ Date start, Date expire, long sig_ttl)
+ {
+ return generatePreRRSIG(rrset, key.getName(), key.getAlgorithm(), key
+ .getFootprint(), start, expire, sig_ttl);
+ }
+
+ /**
+ * Generate from some basic information a prototype SIG RR containing
+ * everything but the actual signature itself.
+ *
+ * @param rec the DNS record being signed (forming an entire RRset).
+ * @param key the public KEY RR counterpart to the key signing the record.
+ * @param start the SIG inception time.
+ * @param expire the SIG expiration time.
+ * @param sig_ttl the TTL of the result SIG record.
+ * @return a prototype signature based on the Record and key information.
+ */
+ public static RRSIGRecord generatePreRRSIG(Record rec, DNSKEYRecord key,
+ Date start, Date expire, long sig_ttl)
+ {
+ return new RRSIGRecord(rec.getName(), rec.getDClass(), sig_ttl, rec
+ .getType(), key.getAlgorithm(), rec.getTTL(), expire, start, key
+ .getFootprint(), key.getName(), null);
+ }
+
+ /**
+ * Generate the binary image of the prototype SIG RR.
+ *
+ * @param presig the SIG RR prototype.
+ * @return the RDATA portion of the prototype SIG record. This forms the
+ * first part of the data to be signed.
+ */
+ private static byte[] generatePreSigRdata(RRSIGRecord presig)
+ {
+ // Generate the binary image;
+ DNSOutput image = new DNSOutput();
+
+ // precalc some things
+ int start_time = (int) (presig.getTimeSigned().getTime() / 1000);
+ int expire_time = (int) (presig.getExpire().getTime() / 1000);
+ Name signer = presig.getSigner();
+
+ // first write out the partial SIG record (this is the SIG RDATA
+ // minus the actual signature.
+ image.writeU16(presig.getTypeCovered());
+ image.writeU8(presig.getAlgorithm());
+ image.writeU8(presig.getLabels());
+ image.writeU32((int) presig.getOrigTTL());
+ image.writeU32(expire_time);
+ image.writeU32(start_time);
+ image.writeU16(presig.getFootprint());
+ image.writeByteArray(signer.toWireCanonical());
+
+ return image.toByteArray();
+ }
+
+ /**
+ * Calculate the canonical wire line format of the RRset.
+ *
+ * @param rrset the RRset to convert.
+ * @param ttl the TTL to use when canonicalizing -- this is generally the
+ * TTL of the signature if there is a pre-existing signature. If
+ * not it is just the ttl of the rrset itself.
+ * @param labels the labels field of the signature, or 0.
+ * @return the canonical wire line format of the rrset. This is the second
+ * part of data to be signed.
+ */
+ public static byte[] generateCanonicalRRsetData(RRset rrset, long ttl,
+ int labels)
+ {
+ DNSOutput image = new DNSOutput();
+
+ if (ttl == 0) ttl = rrset.getTTL();
+ Name n = rrset.getName();
+ if (labels == 0)
+ {
+ labels = n.labels();
+ }
+ else
+ {
+ // correct for Name()'s conception of label count.
+ labels++;
+ }
+ boolean wildcardName = false;
+ if (n.labels() != labels)
+ {
+ n = n.wild(n.labels() - labels);
+ wildcardName = true;
+// log.trace("Detected wildcard expansion: " + rrset.getName() + " changed to " + n);
+ }
+
+ // now convert load the wire format records in the RRset into a
+ // list of byte arrays.
+ ArrayList canonical_rrs = new ArrayList();
+ for (Iterator i = rrset.rrs(); i.hasNext();)
+ {
+ Record r = (Record) i.next();
+ if (r.getTTL() != ttl || wildcardName)
+ {
+ // If necessary, we need to create a new record with a new ttl or ownername.
+ // In the TTL case, this avoids changing the ttl in the response.
+ r = Record.newRecord(n, r.getType(), r.getDClass(), ttl, r
+ .rdataToWireCanonical());
+ }
+ byte[] wire_fmt = r.toWireCanonical();
+ canonical_rrs.add(wire_fmt);
+ }
+
+ // put the records into the correct ordering.
+ // Caculate the offset where the RDATA begins (we have to skip
+ // past the length byte)
+
+ int offset = rrset.getName().toWireCanonical().length + 10;
+ ByteArrayComparator bac = new ByteArrayComparator(offset, false);
+
+ Collections.sort(canonical_rrs, bac);
+
+ for (Iterator i = canonical_rrs.iterator(); i.hasNext();)
+ {
+ byte[] wire_fmt_rec = (byte[]) i.next();
+ image.writeByteArray(wire_fmt_rec);
+ }
+
+ return image.toByteArray();
+ }
+
+ /**
+ * Given an RRset and the prototype signature, generate the canonical data
+ * that is to be signed.
+ *
+ * @param rrset the RRset to be signed.
+ * @param presig a prototype SIG RR created using the same RRset.
+ * @return a block of data ready to be signed.
+ */
+ public static byte[] generateSigData(RRset rrset, RRSIGRecord presig)
+ throws IOException
+ {
+ byte[] rrset_data = generateCanonicalRRsetData(rrset, presig.getOrigTTL(), presig.getLabels());
+
+ return generateSigData(rrset_data, presig);
+ }
+
+ /**
+ * Given an RRset and the prototype signature, generate the canonical data
+ * that is to be signed.
+ *
+ * @param rrset_data the RRset converted into canonical wire line format (as
+ * per the canonicalization rules in RFC 2535).
+ * @param presig the prototype signature based on the same RRset represented
+ * in <code>rrset_data</code>.
+ * @return a block of data ready to be signed.
+ */
+ public static byte[] generateSigData(byte[] rrset_data, RRSIGRecord presig)
+ throws IOException
+ {
+ byte[] sig_rdata = generatePreSigRdata(presig);
+
+ ByteArrayOutputStream image = new ByteArrayOutputStream(sig_rdata.length
+ + rrset_data.length);
+
+ image.write(sig_rdata);
+ image.write(rrset_data);
+
+ return image.toByteArray();
+ }
+
+ /**
+ * Given the acutal signature an the prototype signature, combine them and
+ * return the fully formed SIGRecord.
+ *
+ * @param signature the cryptographic signature, in DNSSEC format.
+ * @param presig the prototype SIG RR to add the signature to.
+ * @return the fully formed SIG RR.
+ */
+ public static RRSIGRecord generateRRSIG(byte[] signature, RRSIGRecord presig)
+ {
+ return new RRSIGRecord(presig.getName(), presig.getDClass(), presig
+ .getTTL(), presig.getTypeCovered(), presig.getAlgorithm(), presig
+ .getOrigTTL(), presig.getExpire(), presig.getTimeSigned(), presig
+ .getFootprint(), presig.getSigner(), signature);
+ }
+
+ /**
+ * Converts from a RFC 2536 formatted DSA signature to a JCE (ASN.1)
+ * formatted signature.
+ *
+ * <p>
+ * ASN.1 format = ASN1_SEQ . seq_length . ASN1_INT . Rlength . R . ANS1_INT .
+ * Slength . S
+ * </p>
+ *
+ * The integers R and S may have a leading null byte to force the integer
+ * positive.
+ *
+ * @param signature the RFC 2536 formatted DSA signature.
+ * @return The ASN.1 formatted DSA signature.
+ * @throws SignatureException if there was something wrong with the RFC 2536
+ * formatted signature.
+ */
+ public static byte[] convertDSASignature(byte[] signature)
+ throws SignatureException
+ {
+ if (signature.length != 41)
+ throw new SignatureException("RFC 2536 signature not expected length.");
+
+ byte r_pad = 0;
+ byte s_pad = 0;
+
+ // handle initial null byte padding.
+ if (signature[1] < 0) r_pad++;
+ if (signature[21] < 0) s_pad++;
+
+ // ASN.1 length = R length + S length + (2 + 2 + 2), where each 2
+ // is for a ASN.1 type-length byte pair of which there are three
+ // (SEQ, INT, INT).
+ byte sig_length = (byte) (40 + r_pad + s_pad + 6);
+
+ byte sig[] = new byte[sig_length];
+ byte pos = 0;
+
+ sig[pos++] = ASN1_SEQ;
+ sig[pos++] = (byte) (sig_length - 2); // all but the SEQ type+length.
+ sig[pos++] = ASN1_INT;
+ sig[pos++] = (byte) (20 + r_pad);
+
+ // copy the value of R, leaving a null byte if necessary
+ if (r_pad == 1) sig[pos++] = 0;
+
+ System.arraycopy(signature, 1, sig, pos, 20);
+ pos += 20;
+
+ sig[pos++] = ASN1_INT;
+ sig[pos++] = (byte) (20 + s_pad);
+
+ // copy the value of S, leaving a null byte if necessary
+ if (s_pad == 1) sig[pos++] = 0;
+
+ System.arraycopy(signature, 21, sig, pos, 20);
+
+ return sig;
+ }
+
+ /**
+ * Converts from a JCE (ASN.1) formatted DSA signature to a RFC 2536
+ * compliant signature.
+ *
+ * <p>
+ * rfc2536 format = T . R . S
+ * </p>
+ *
+ * where T is a number between 0 and 8, which is based on the DSA key
+ * length, and R & S are formatted to be exactly 20 bytes each (no leading
+ * null bytes).
+ *
+ * @param params the DSA parameters associated with the DSA key used to
+ * generate the signature.
+ * @param signature the ASN.1 formatted DSA signature.
+ * @return a RFC 2536 formatted DSA signature.
+ * @throws SignatureException if something is wrong with the ASN.1 format.
+ */
+ public static byte[] convertDSASignature(DSAParams params, byte[] signature)
+ throws SignatureException
+ {
+ if (signature[0] != ASN1_SEQ || signature[2] != ASN1_INT)
+ {
+ throw new SignatureException(
+ "Invalid ASN.1 signature format: expected SEQ, INT");
+ }
+
+ byte r_pad = (byte) (signature[3] - 20);
+
+ if (signature[24 + r_pad] != ASN1_INT)
+ {
+ throw new SignatureException(
+ "Invalid ASN.1 signature format: expected SEQ, INT, INT");
+ }
+
+// log.trace("(start) ASN.1 DSA Sig:\n" + base64.toString(signature));
+
+ byte s_pad = (byte) (signature[25 + r_pad] - 20);
+
+ byte[] sig = new byte[41]; // all rfc2536 signatures are 41 bytes.
+
+ // Calculate T:
+ sig[0] = (byte) ((params.getP().bitLength() - 512) / 64);
+
+ // copy R value
+ if (r_pad >= 0)
+ {
+ System.arraycopy(signature, 4 + r_pad, sig, 1, 20);
+ }
+ else
+ {
+ // R is shorter than 20 bytes, so right justify the number
+ // (r_pad is negative here, remember?).
+ Arrays.fill(sig, 1, 1 - r_pad, (byte) 0);
+ System.arraycopy(signature, 4, sig, 1 - r_pad, 20 + r_pad);
+ }
+
+ // copy S value
+ if (s_pad >= 0)
+ {
+ System.arraycopy(signature, 26 + r_pad + s_pad, sig, 21, 20);
+ }
+ else
+ {
+ // S is shorter than 20 bytes, so right justify the number
+ // (s_pad is negative here).
+ Arrays.fill(sig, 21, 21 - s_pad, (byte) 0);
+ System.arraycopy(signature, 26 + r_pad, sig, 21 - s_pad, 20 + s_pad);
+ }
+
+// if (r_pad < 0 || s_pad < 0)
+// {
+// log.trace("(finish ***) RFC 2536 DSA Sig:\n" + base64.toString(sig));
+//
+// }
+// else
+// {
+// log.trace("(finish) RFC 2536 DSA Sig:\n" + base64.toString(sig));
+// }
+
+ return sig;
+ }
+}