1 /***************************** -*- Java -*- ********************************\
3 * Copyright (c) 2009 VeriSign, Inc. All rights reserved. *
5 * This software is provided solely in connection with the terms of the *
6 * license agreement. Any other use without the prior express written *
7 * permission of VeriSign is completely prohibited. The software and *
8 * documentation are "Commercial Items", as that term is defined in 48 *
9 * C.F.R. section 2.101, consisting of "Commercial Computer Software" and *
10 * "Commercial Computer Software Documentation" as such terms are defined *
11 * in 48 C.F.R. section 252.227-7014(a)(5) and 48 C.F.R. section *
12 * 252.227-7014(a)(1), and used in 48 C.F.R. section 12.212 and 48 C.F.R. *
13 * section 227.7202, as applicable. Pursuant to the above and other *
14 * relevant sections of the Code of Federal Regulations, as applicable, *
15 * VeriSign's publications, commercial computer software, and commercial *
16 * computer software documentation are distributed and licensed to United *
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22 \***************************************************************************/
24 package com.verisign.tat.dnssec;
26 import org.apache.log4j.Logger;
28 import org.xbill.DNS.DNSKEYRecord;
29 import org.xbill.DNS.DNSOutput;
30 import org.xbill.DNS.Name;
31 import org.xbill.DNS.RRSIGRecord;
32 import org.xbill.DNS.RRset;
33 import org.xbill.DNS.Record;
34 import org.xbill.DNS.utils.base64;
36 import java.io.ByteArrayOutputStream;
37 import java.io.IOException;
38 import java.io.Serializable;
40 import java.security.SignatureException;
41 import java.security.interfaces.DSAParams;
43 import java.util.ArrayList;
44 import java.util.Arrays;
45 import java.util.Collections;
46 import java.util.Comparator;
47 import java.util.Date;
48 import java.util.Iterator;
51 * This class contains a bunch of utility methods that are generally useful in
52 * signing and verifying rrsets.
54 public class SignUtils {
55 // private static final int DSA_SIGNATURE_LENGTH = 20;
56 private static final int ASN1_INT = 0x02;
57 private static final int ASN1_SEQ = 0x30;
58 public static final int RR_NORMAL = 0;
59 public static final int RR_DELEGATION = 1;
60 public static final int RR_GLUE = 2;
61 public static final int RR_INVALID = 3;
63 private static Logger log = Logger.getLogger(SignUtils.class);
66 * Generate from some basic information a prototype SIG RR containing
67 * everything but the actual signature itself.
70 * the RRset being signed.
72 * the name of the signing key
74 * the algorithm of the signing key
76 * the keyid (or footprint) of the signing key
78 * the SIG inception time.
80 * the SIG expiration time.
82 * the TTL of the resulting SIG record.
83 * @return a prototype signature based on the RRset and key information.
85 public static RRSIGRecord generatePreRRSIG(RRset rrset,
92 return new RRSIGRecord(rrset.getName(), rrset.getDClass(), sig_ttl,
93 rrset.getType(), alg, rrset.getTTL(), expire, start, keyid,
98 * Generate from some basic information a prototype SIG RR
99 * containing everything but the actual signature itself.
102 * the RRset being signed.
104 * the public KEY RR counterpart to the key being used
107 * the SIG inception time.
109 * the SIG expiration time.
111 * the TTL of the resulting SIG record.
112 * @return a prototype signature based on the RRset and key information.
114 public static RRSIGRecord generatePreRRSIG(RRset rrset,
119 return generatePreRRSIG(rrset, key.getName(), key.getAlgorithm(),
120 key.getFootprint(), start, expire, sig_ttl);
124 * Generate from some basic information a prototype SIG RR
125 * containing everything but the actual signature itself.
128 * the DNS record being signed (forming an entire RRset).
130 * the public KEY RR counterpart to the key signing the record.
132 * the SIG inception time.
134 * the SIG expiration time.
136 * the TTL of the result SIG record.
137 * @return a prototype signature based on the Record and key information.
139 public static RRSIGRecord generatePreRRSIG(Record rec,
144 return new RRSIGRecord(rec.getName(), rec.getDClass(), sig_ttl,
145 rec.getType(), key.getAlgorithm(), rec.getTTL(),
146 expire, start, key.getFootprint(), key.getName(), null);
150 * Generate the binary image of the prototype SIG RR.
153 * the SIG RR prototype.
154 * @return the RDATA portion of the prototype SIG record. This forms the
155 * first part of the data to be signed.
157 private static byte[] generatePreSigRdata(RRSIGRecord presig) {
158 // Generate the binary image;
159 DNSOutput image = new DNSOutput();
161 // precalculate some things
162 int start_time = (int) (presig.getTimeSigned().getTime() / 1000);
163 int expire_time = (int) (presig.getExpire().getTime() / 1000);
164 Name signer = presig.getSigner();
166 // first write out the partial SIG record (this is the SIG RDATA
167 // minus the actual signature.
168 image.writeU16(presig.getTypeCovered());
169 image.writeU8(presig.getAlgorithm());
170 image.writeU8(presig.getLabels());
171 image.writeU32((int) presig.getOrigTTL());
172 image.writeU32(expire_time);
173 image.writeU32(start_time);
174 image.writeU16(presig.getFootprint());
175 image.writeByteArray(signer.toWireCanonical());
177 return image.toByteArray();
181 * Calculate the canonical wire line format of the RRset.
184 * the RRset to convert.
186 * the TTL to use when canonicalizing -- this is generally the
187 * TTL of the signature if there is a pre-existing signature. If
188 * not it is just the ttl of the rrset itself.
190 * the labels field of the signature, or 0.
191 * @return the canonical wire line format of the rrset. This is the second
192 * part of data to be signed.
194 @SuppressWarnings("rawtypes")
195 public static byte[] generateCanonicalRRsetData(RRset rrset, long ttl, int labels) {
196 DNSOutput image = new DNSOutput();
199 ttl = rrset.getTTL();
202 Name n = rrset.getName();
207 // correct for Name()'s conception of label count.
211 boolean wildcardName = false;
213 if (n.labels() != labels) {
214 n = n.wild(n.labels() - labels);
216 log.trace("Detected wildcard expansion: " + rrset.getName() +
220 // now convert the wire format records in the RRset into a
221 // list of byte arrays.
222 ArrayList<byte[]> canonical_rrs = new ArrayList<byte[]>();
224 for (Iterator i = rrset.rrs(); i.hasNext();) {
225 Record r = (Record) i.next();
227 if ((r.getTTL() != ttl) || wildcardName) {
228 // If necessary, we need to create a new record with a new ttl
230 // In the TTL case, this avoids changing the ttl in the
232 r = Record.newRecord(n, r.getType(), r.getDClass(), ttl,
233 r.rdataToWireCanonical());
236 byte[] wire_fmt = r.toWireCanonical();
237 canonical_rrs.add(wire_fmt);
240 // put the records into the correct ordering.
241 // Calculate the offset where the RDATA begins (we have to skip
242 // past the length byte)
243 int offset = rrset.getName().toWireCanonical().length + 10;
244 ByteArrayComparator bac = new ByteArrayComparator(offset, false);
246 Collections.sort(canonical_rrs, bac);
248 for (Iterator<byte[]> i = canonical_rrs.iterator(); i.hasNext();) {
249 byte[] wire_fmt_rec = i.next();
250 image.writeByteArray(wire_fmt_rec);
253 return image.toByteArray();
257 * Given an RRset and the prototype signature, generate the
258 * canonical data that is to be signed.
261 * the RRset to be signed.
263 * a prototype SIG RR created using the same RRset.
264 * @return a block of data ready to be signed.
266 public static byte[] generateSigData(RRset rrset, RRSIGRecord presig)
268 byte[] rrset_data = generateCanonicalRRsetData(rrset, presig.getOrigTTL(), presig.getLabels());
270 return generateSigData(rrset_data, presig);
274 * Given an RRset and the prototype signature, generate the
275 * canonical data that is to be signed.
278 * the RRset converted into canonical wire line format (as per
279 * the canonicalization rules in RFC 2535).
281 * the prototype signature based on the same RRset represented in
282 * <code>rrset_data</code>.
283 * @return a block of data ready to be signed.
285 public static byte[] generateSigData(byte[] rrset_data, RRSIGRecord presig)
287 byte[] sig_rdata = generatePreSigRdata(presig);
289 ByteArrayOutputStream image = new ByteArrayOutputStream(sig_rdata.length + rrset_data.length);
291 image.write(sig_rdata);
292 image.write(rrset_data);
294 return image.toByteArray();
298 * Given the actual signature and the prototype signature, combine
299 * them and return the fully formed RRSIGRecord.
302 * the cryptographic signature, in DNSSEC format.
304 * the prototype RRSIG RR to add the signature to.
305 * @return the fully formed RRSIG RR.
307 public static RRSIGRecord generateRRSIG(byte[] signature, RRSIGRecord presig) {
308 return new RRSIGRecord(presig.getName(), presig.getDClass(),
309 presig.getTTL(), presig.getTypeCovered(), presig.getAlgorithm(),
310 presig.getOrigTTL(), presig.getExpire(), presig.getTimeSigned(),
311 presig.getFootprint(), presig.getSigner(), signature);
315 * Converts from a RFC 2536 formatted DSA signature to a JCE
316 * (ASN.1) formatted signature.
319 * ASN.1 format = ASN1_SEQ . seq_length . ASN1_INT . Rlength . R . ANS1_INT
323 * The integers R and S may have a leading null byte to force the
327 * the RFC 2536 formatted DSA signature.
328 * @return The ASN.1 formatted DSA signature.
329 * @throws SignatureException
330 * if there was something wrong with the RFC 2536 formatted
333 public static byte[] convertDSASignature(byte[] signature)
334 throws SignatureException {
335 if (signature.length != 41) {
336 throw new SignatureException("RFC 2536 signature not expected length.");
342 // handle initial null byte padding.
343 if (signature[1] < 0) {
347 if (signature[21] < 0) {
351 // ASN.1 length = R length + S length + (2 + 2 + 2), where each 2
352 // is for a ASN.1 type-length byte pair of which there are three
354 byte sig_length = (byte) (40 + r_pad + s_pad + 6);
356 byte[] sig = new byte[sig_length];
359 sig[pos++] = ASN1_SEQ;
360 sig[pos++] = (byte) (sig_length - 2); // all but the SEQ type+length.
361 sig[pos++] = ASN1_INT;
362 sig[pos++] = (byte) (20 + r_pad);
364 // copy the value of R, leaving a null byte if necessary
369 System.arraycopy(signature, 1, sig, pos, 20);
372 sig[pos++] = ASN1_INT;
373 sig[pos++] = (byte) (20 + s_pad);
375 // copy the value of S, leaving a null byte if necessary
380 System.arraycopy(signature, 21, sig, pos, 20);
386 * Converts from a JCE (ASN.1) formatted DSA signature to a RFC
387 * 2536 compliant signature.
390 * rfc2536 format = T . R . S
393 * where T is a number between 0 and 8, which is based on the DSA key
394 * length, and R & S are formatted to be exactly 20 bytes each (no leading
398 * the DSA parameters associated with the DSA key used to
399 * generate the signature.
401 * the ASN.1 formatted DSA signature.
402 * @return a RFC 2536 formatted DSA signature.
403 * @throws SignatureException
404 * if something is wrong with the ASN.1 format.
406 public static byte[] convertDSASignature(DSAParams params, byte[] signature)
407 throws SignatureException {
408 if ((signature[0] != ASN1_SEQ) || (signature[2] != ASN1_INT)) {
409 throw new SignatureException("Invalid ASN.1 signature format: expected SEQ, INT");
412 byte r_pad = (byte) (signature[3] - 20);
414 if (signature[24 + r_pad] != ASN1_INT) {
415 throw new SignatureException("Invalid ASN.1 signature format: expected SEQ, INT, INT");
418 log.trace("(start) ASN.1 DSA Sig:\n" + base64.toString(signature));
420 byte s_pad = (byte) (signature[25 + r_pad] - 20);
422 byte[] sig = new byte[41]; // all rfc2536 signatures are 41 bytes.
425 sig[0] = (byte) ((params.getP().bitLength() - 512) / 64);
429 System.arraycopy(signature, 4 + r_pad, sig, 1, 20);
431 // R is shorter than 20 bytes, so right justify the number
432 // (r_pad is negative here, remember?).
433 Arrays.fill(sig, 1, 1 - r_pad, (byte) 0);
434 System.arraycopy(signature, 4, sig, 1 - r_pad, 20 + r_pad);
439 System.arraycopy(signature, 26 + r_pad + s_pad, sig, 21, 20);
441 // S is shorter than 20 bytes, so right justify the number
442 // (s_pad is negative here).
443 Arrays.fill(sig, 21, 21 - s_pad, (byte) 0);
444 System.arraycopy(signature, 26 + r_pad, sig, 21 - s_pad, 20 + s_pad);
447 if ((r_pad < 0) || (s_pad < 0)) {
448 log.trace("(finish ***) RFC 2536 DSA Sig:\n" + base64.toString(sig));
450 log.trace("(finish) RFC 2536 DSA Sig:\n" + base64.toString(sig));
457 * This class implements a basic comparator for byte arrays. It is
458 * primarily useful for comparing RDATA portions of DNS records in
459 * doing DNSSEC canonical ordering.
461 public static class ByteArrayComparator implements Comparator<byte[]>, Serializable {
462 private static final long serialVersionUID = 1L;
463 private int mOffset = 0;
464 private boolean mDebug = false;
466 public ByteArrayComparator() { }
468 public ByteArrayComparator(int offset, boolean debug) {
473 public int compare(byte[] b1, byte[] b2) throws ClassCastException {
474 for (int i = mOffset; (i < b1.length) && (i < b2.length); i++) {
475 if (b1[i] != b2[i]) {
477 System.out.println("offset " + i + " differs (this is " + (i - mOffset) +
478 " bytes in from our offset.)");
481 return (b1[i] & 0xFF) - (b2[i] & 0xFF);
485 return b1.length - b2.length;