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;
39 import java.security.SignatureException;
40 import java.security.interfaces.DSAParams;
42 import java.util.ArrayList;
43 import java.util.Arrays;
44 import java.util.Collections;
45 import java.util.Comparator;
46 import java.util.Date;
47 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;
62 private static Logger log = Logger.getLogger(SignUtils.class);
65 * Generate from some basic information a prototype SIG RR containing
66 * everything but the actual signature itself.
69 * the RRset being signed.
71 * the name of the signing key
73 * the algorithm of the signing key
75 * the keyid (or footprint) of the signing key
77 * the SIG inception time.
79 * the SIG expiration time.
81 * the TTL of the resulting SIG record.
82 * @return a prototype signature based on the RRset and key information.
84 public static RRSIGRecord generatePreRRSIG(RRset rrset, Name signer,
85 int alg, int keyid, Date start, Date expire, long sig_ttl) {
86 return new RRSIGRecord(rrset.getName(), rrset.getDClass(), sig_ttl,
87 rrset.getType(), alg, rrset.getTTL(), expire, start, keyid, signer,
92 * Generate from some basic information a prototype SIG RR containing
93 * everything but the actual signature itself.
96 * the RRset being signed.
98 * the public KEY RR counterpart to the key being used to sign
101 * the SIG inception time.
103 * the SIG expiration time.
105 * the TTL of the resulting SIG record.
106 * @return a prototype signature based on the RRset and key information.
108 public static RRSIGRecord generatePreRRSIG(RRset rrset, DNSKEYRecord key,
109 Date start, Date expire, long sig_ttl) {
110 return generatePreRRSIG(rrset, key.getName(), key.getAlgorithm(),
111 key.getFootprint(), start, expire, sig_ttl);
115 * Generate from some basic information a prototype SIG RR containing
116 * everything but the actual signature itself.
119 * the DNS record being signed (forming an entire RRset).
121 * the public KEY RR counterpart to the key signing the record.
123 * the SIG inception time.
125 * the SIG expiration time.
127 * the TTL of the result SIG record.
128 * @return a prototype signature based on the Record and key information.
130 public static RRSIGRecord generatePreRRSIG(Record rec, DNSKEYRecord key,
131 Date start, Date expire, long sig_ttl) {
132 return new RRSIGRecord(rec.getName(), rec.getDClass(), sig_ttl,
133 rec.getType(), key.getAlgorithm(), rec.getTTL(), expire, start,
134 key.getFootprint(), key.getName(), null);
138 * Generate the binary image of the prototype SIG RR.
141 * the SIG RR prototype.
142 * @return the RDATA portion of the prototype SIG record. This forms the
143 * first part of the data to be signed.
145 private static byte [] generatePreSigRdata(RRSIGRecord presig) {
146 // Generate the binary image;
147 DNSOutput image = new DNSOutput();
149 // precalculate some things
150 int start_time = (int) (presig.getTimeSigned().getTime() / 1000);
151 int expire_time = (int) (presig.getExpire().getTime() / 1000);
152 Name signer = presig.getSigner();
154 // first write out the partial SIG record (this is the SIG RDATA
155 // minus the actual signature.
156 image.writeU16(presig.getTypeCovered());
157 image.writeU8(presig.getAlgorithm());
158 image.writeU8(presig.getLabels());
159 image.writeU32((int) presig.getOrigTTL());
160 image.writeU32(expire_time);
161 image.writeU32(start_time);
162 image.writeU16(presig.getFootprint());
163 image.writeByteArray(signer.toWireCanonical());
165 return image.toByteArray();
169 * Calculate the canonical wire line format of the RRset.
172 * the RRset to convert.
174 * the TTL to use when canonicalizing -- this is generally the
175 * TTL of the signature if there is a pre-existing signature. If
176 * not it is just the ttl of the rrset itself.
178 * the labels field of the signature, or 0.
179 * @return the canonical wire line format of the rrset. This is the second
180 * part of data to be signed.
182 @SuppressWarnings("unchecked")
183 public static byte [] generateCanonicalRRsetData(RRset rrset, long ttl,
185 DNSOutput image = new DNSOutput();
188 ttl = rrset.getTTL();
191 Name n = rrset.getName();
196 // correct for Name()'s conception of label count.
200 boolean wildcardName = false;
202 if (n.labels() != labels) {
203 n = n.wild(n.labels() - labels);
205 log.trace("Detected wildcard expansion: " + rrset.getName() +
209 // now convert the wire format records in the RRset into a
210 // list of byte arrays.
211 ArrayList<byte []> canonical_rrs = new ArrayList<byte []>();
213 for (Iterator i = rrset.rrs(); i.hasNext();) {
214 Record r = (Record) i.next();
216 if ((r.getTTL() != ttl) || wildcardName) {
217 // If necessary, we need to create a new record with a new ttl
219 // In the TTL case, this avoids changing the ttl in the
221 r = Record.newRecord(n, r.getType(), r.getDClass(), ttl,
222 r.rdataToWireCanonical());
225 byte [] wire_fmt = r.toWireCanonical();
226 canonical_rrs.add(wire_fmt);
229 // put the records into the correct ordering.
230 // Calculate the offset where the RDATA begins (we have to skip
231 // past the length byte)
232 int offset = rrset.getName().toWireCanonical().length +
234 ByteArrayComparator bac = new ByteArrayComparator(offset, false);
236 Collections.sort(canonical_rrs, bac);
238 for (Iterator<byte []> i = canonical_rrs.iterator(); i.hasNext();) {
239 byte [] wire_fmt_rec = i.next();
240 image.writeByteArray(wire_fmt_rec);
243 return image.toByteArray();
247 * Given an RRset and the prototype signature, generate the canonical data
248 * that is to be signed.
251 * the RRset to be signed.
253 * a prototype SIG RR created using the same RRset.
254 * @return a block of data ready to be signed.
256 public static byte [] generateSigData(RRset rrset, RRSIGRecord presig)
258 byte [] rrset_data = generateCanonicalRRsetData(rrset,
259 presig.getOrigTTL(), presig.getLabels());
261 return generateSigData(rrset_data, presig);
265 * Given an RRset and the prototype signature, generate the canonical data
266 * that is to be signed.
269 * the RRset converted into canonical wire line format (as per
270 * the canonicalization rules in RFC 2535).
272 * the prototype signature based on the same RRset represented in
273 * <code>rrset_data</code>.
274 * @return a block of data ready to be signed.
276 public static byte [] generateSigData(byte [] rrset_data, RRSIGRecord presig)
278 byte [] sig_rdata = generatePreSigRdata(presig);
280 ByteArrayOutputStream image = new ByteArrayOutputStream(sig_rdata.length +
283 image.write(sig_rdata);
284 image.write(rrset_data);
286 return image.toByteArray();
290 * Given the actual signature and the prototype signature, combine them and
291 * return the fully formed RRSIGRecord.
294 * the cryptographic signature, in DNSSEC format.
296 * the prototype RRSIG RR to add the signature to.
297 * @return the fully formed RRSIG RR.
299 public static RRSIGRecord generateRRSIG(byte [] signature,
300 RRSIGRecord presig) {
301 return new RRSIGRecord(presig.getName(), presig.getDClass(),
302 presig.getTTL(), presig.getTypeCovered(), presig.getAlgorithm(),
303 presig.getOrigTTL(), presig.getExpire(), presig.getTimeSigned(),
304 presig.getFootprint(), presig.getSigner(), signature);
308 * Converts from a RFC 2536 formatted DSA signature to a JCE (ASN.1)
309 * formatted signature.
312 * ASN.1 format = ASN1_SEQ . seq_length . ASN1_INT . Rlength . R . ANS1_INT
316 * The integers R and S may have a leading null byte to force the integer
320 * the RFC 2536 formatted DSA signature.
321 * @return The ASN.1 formatted DSA signature.
322 * @throws SignatureException
323 * if there was something wrong with the RFC 2536 formatted
326 public static byte [] convertDSASignature(byte [] signature)
327 throws SignatureException {
328 if (signature.length != 41) {
329 throw new SignatureException(
330 "RFC 2536 signature not expected length.");
336 // handle initial null byte padding.
337 if (signature[1] < 0) {
341 if (signature[21] < 0) {
345 // ASN.1 length = R length + S length + (2 + 2 + 2), where each 2
346 // is for a ASN.1 type-length byte pair of which there are three
348 byte sig_length = (byte) (40 + r_pad + s_pad + 6);
350 byte [] sig = new byte[sig_length];
353 sig[pos++] = ASN1_SEQ;
354 sig[pos++] = (byte) (sig_length - 2); // all but the SEQ type+length.
355 sig[pos++] = ASN1_INT;
356 sig[pos++] = (byte) (20 + r_pad);
358 // copy the value of R, leaving a null byte if necessary
363 System.arraycopy(signature, 1, sig, pos, 20);
366 sig[pos++] = ASN1_INT;
367 sig[pos++] = (byte) (20 + s_pad);
369 // copy the value of S, leaving a null byte if necessary
374 System.arraycopy(signature, 21, sig, pos, 20);
380 * Converts from a JCE (ASN.1) formatted DSA signature to a RFC 2536
381 * compliant signature.
384 * rfc2536 format = T . R . S
387 * where T is a number between 0 and 8, which is based on the DSA key
388 * length, and R & S are formatted to be exactly 20 bytes each (no leading
392 * the DSA parameters associated with the DSA key used to
393 * generate the signature.
395 * the ASN.1 formatted DSA signature.
396 * @return a RFC 2536 formatted DSA signature.
397 * @throws SignatureException
398 * if something is wrong with the ASN.1 format.
400 public static byte [] convertDSASignature(DSAParams params,
401 byte [] signature) throws SignatureException {
402 if ((signature[0] != ASN1_SEQ) || (signature[2] != ASN1_INT)) {
403 throw new SignatureException(
404 "Invalid ASN.1 signature format: expected SEQ, INT");
407 byte r_pad = (byte) (signature[3] - 20);
409 if (signature[24 + r_pad] != ASN1_INT) {
410 throw new SignatureException(
411 "Invalid ASN.1 signature format: expected SEQ, INT, INT");
414 log.trace("(start) ASN.1 DSA Sig:\n" + base64.toString(signature));
416 byte s_pad = (byte) (signature[25 + r_pad] - 20);
418 byte [] sig = new byte[41]; // all rfc2536 signatures are 41 bytes.
421 sig[0] = (byte) ((params.getP().bitLength() - 512) / 64);
425 System.arraycopy(signature, 4 + r_pad, sig, 1, 20);
427 // R is shorter than 20 bytes, so right justify the number
428 // (r_pad is negative here, remember?).
429 Arrays.fill(sig, 1, 1 - r_pad, (byte) 0);
430 System.arraycopy(signature, 4, sig, 1 - r_pad, 20 + r_pad);
435 System.arraycopy(signature, 26 + r_pad + s_pad, sig, 21, 20);
437 // S is shorter than 20 bytes, so right justify the number
438 // (s_pad is negative here).
439 Arrays.fill(sig, 21, 21 - s_pad, (byte) 0);
440 System.arraycopy(signature, 26 + r_pad, sig, 21 - s_pad, 20 +
444 if ((r_pad < 0) || (s_pad < 0)) {
445 log.trace("(finish ***) RFC 2536 DSA Sig:\n" +
446 base64.toString(sig));
448 log.trace("(finish) RFC 2536 DSA Sig:\n" + base64.toString(sig));
455 * This class implements a basic comparator for byte arrays. It is primarily
456 * useful for comparing RDATA portions of DNS records in doing DNSSEC
457 * canonical ordering.
459 public static class ByteArrayComparator implements Comparator<byte []> {
460 private int mOffset = 0;
461 private boolean mDebug = false;
463 public ByteArrayComparator() {}
465 public ByteArrayComparator(int offset, boolean debug) {
470 public int compare(byte [] b1, byte [] b2) throws ClassCastException {
471 for (int i = mOffset; (i < b1.length) && (i < b2.length); i++) {
472 if (b1[i] != b2[i]) {
474 System.out.println("offset " + i +
475 " differs (this is " + (i - mOffset) +
476 " bytes in from our offset.)");
479 return (b1[i] & 0xFF) - (b2[i] & 0xFF);
483 return b1.length - b2.length;