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 *
17 * States Government end users with only those rights as granted to all *
18 * other end users, according to the terms and conditions contained in the *
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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;
50 * This class contains a bunch of utility methods that are generally useful in
51 * signing and verifying rrsets.
53 public class SignUtils {
54 // private static final int DSA_SIGNATURE_LENGTH = 20;
55 private static final int ASN1_INT = 0x02;
56 private static final int ASN1_SEQ = 0x30;
57 public static final int RR_NORMAL = 0;
58 public static final int RR_DELEGATION = 1;
59 public static final int RR_GLUE = 2;
60 public static final int RR_INVALID = 3;
61 private static Logger log = Logger.getLogger(SignUtils.class);
64 * Generate from some basic information a prototype SIG RR containing
65 * everything but the actual signature itself.
68 * the RRset being signed.
70 * the name of the signing key
72 * the algorithm of the signing key
74 * the keyid (or footprint) of the signing key
76 * the SIG inception time.
78 * the SIG expiration time.
80 * the TTL of the resulting SIG record.
81 * @return a prototype signature based on the RRset and key information.
83 public static RRSIGRecord generatePreRRSIG(RRset rrset, Name signer,
84 int alg, int keyid, Date start, Date expire, long sig_ttl) {
85 return new RRSIGRecord(rrset.getName(), rrset.getDClass(), sig_ttl,
86 rrset.getType(), alg, rrset.getTTL(), expire, start, keyid,
91 * Generate from some basic information a prototype SIG RR containing
92 * everything but the actual signature itself.
95 * the RRset being signed.
97 * the public KEY RR counterpart to the key being used to sign
100 * the SIG inception time.
102 * the SIG expiration time.
104 * the TTL of the resulting SIG record.
105 * @return a prototype signature based on the RRset and key information.
107 public static RRSIGRecord generatePreRRSIG(RRset rrset, DNSKEYRecord key,
108 Date start, Date expire, long sig_ttl) {
109 return generatePreRRSIG(rrset, key.getName(), key.getAlgorithm(), key
110 .getFootprint(), start, expire, sig_ttl);
114 * Generate from some basic information a prototype SIG RR containing
115 * everything but the actual signature itself.
118 * the DNS record being signed (forming an entire RRset).
120 * the public KEY RR counterpart to the key signing the record.
122 * the SIG inception time.
124 * the SIG expiration time.
126 * the TTL of the result SIG record.
127 * @return a prototype signature based on the Record and key information.
129 public static RRSIGRecord generatePreRRSIG(Record rec, DNSKEYRecord key,
130 Date start, Date expire, long sig_ttl) {
131 return new RRSIGRecord(rec.getName(), rec.getDClass(), sig_ttl, rec
132 .getType(), key.getAlgorithm(), rec.getTTL(), expire, start,
133 key.getFootprint(), key.getName(), null);
137 * Generate the binary image of the prototype SIG RR.
140 * the SIG RR prototype.
141 * @return the RDATA portion of the prototype SIG record. This forms the
142 * first part of the data to be signed.
144 private static byte[] generatePreSigRdata(RRSIGRecord presig) {
145 // Generate the binary image;
146 DNSOutput image = new DNSOutput();
148 // precalculate some things
149 int start_time = (int) (presig.getTimeSigned().getTime() / 1000);
150 int expire_time = (int) (presig.getExpire().getTime() / 1000);
151 Name signer = presig.getSigner();
153 // first write out the partial SIG record (this is the SIG RDATA
154 // minus the actual signature.
155 image.writeU16(presig.getTypeCovered());
156 image.writeU8(presig.getAlgorithm());
157 image.writeU8(presig.getLabels());
158 image.writeU32((int) presig.getOrigTTL());
159 image.writeU32(expire_time);
160 image.writeU32(start_time);
161 image.writeU16(presig.getFootprint());
162 image.writeByteArray(signer.toWireCanonical());
164 return image.toByteArray();
168 * Calculate the canonical wire line format of the RRset.
171 * the RRset to convert.
173 * the TTL to use when canonicalizing -- this is generally the
174 * TTL of the signature if there is a pre-existing signature. If
175 * not it is just the ttl of the rrset itself.
177 * the labels field of the signature, or 0.
178 * @return the canonical wire line format of the rrset. This is the second
179 * part of data to be signed.
181 @SuppressWarnings("unchecked")
182 public static byte[] generateCanonicalRRsetData(RRset rrset, long ttl,
184 DNSOutput image = new DNSOutput();
187 ttl = rrset.getTTL();
190 Name n = rrset.getName();
195 // correct for Name()'s conception of label count.
199 boolean wildcardName = false;
201 if (n.labels() != labels) {
202 n = n.wild(n.labels() - labels);
204 log.trace("Detected wildcard expansion: " + rrset.getName()
205 + " changed to " + n);
208 // now convert the wire format records in the RRset into a
209 // list of byte arrays.
210 ArrayList<byte[]> canonical_rrs = new ArrayList<byte[]>();
212 for (Iterator i = rrset.rrs(); i.hasNext();) {
213 Record r = (Record) i.next();
215 if ((r.getTTL() != ttl) || wildcardName) {
216 // If necessary, we need to create a new record with a new ttl
218 // In the TTL case, this avoids changing the ttl in the
220 r = Record.newRecord(n, r.getType(), r.getDClass(), ttl, r
221 .rdataToWireCanonical());
224 byte[] wire_fmt = r.toWireCanonical();
225 canonical_rrs.add(wire_fmt);
228 // put the records into the correct ordering.
229 // Calculate the offset where the RDATA begins (we have to skip
230 // past the length byte)
231 int offset = rrset.getName().toWireCanonical().length + 10;
232 ByteArrayComparator bac = new ByteArrayComparator(offset, false);
234 Collections.sort(canonical_rrs, bac);
236 for (Iterator<byte[]> i = canonical_rrs.iterator(); i.hasNext();) {
237 byte[] wire_fmt_rec = i.next();
238 image.writeByteArray(wire_fmt_rec);
241 return image.toByteArray();
245 * Given an RRset and the prototype signature, generate the canonical data
246 * that is to be signed.
249 * the RRset to be signed.
251 * a prototype SIG RR created using the same RRset.
252 * @return a block of data ready to be signed.
254 public static byte[] generateSigData(RRset rrset, RRSIGRecord presig)
256 byte[] rrset_data = generateCanonicalRRsetData(rrset, presig
257 .getOrigTTL(), presig.getLabels());
259 return generateSigData(rrset_data, presig);
263 * Given an RRset and the prototype signature, generate the canonical data
264 * that is to be signed.
267 * the RRset converted into canonical wire line format (as per
268 * the canonicalization rules in RFC 2535).
270 * the prototype signature based on the same RRset represented in
271 * <code>rrset_data</code>.
272 * @return a block of data ready to be signed.
274 public static byte[] generateSigData(byte[] rrset_data, RRSIGRecord presig)
276 byte[] sig_rdata = generatePreSigRdata(presig);
278 ByteArrayOutputStream image = new ByteArrayOutputStream(
279 sig_rdata.length + rrset_data.length);
281 image.write(sig_rdata);
282 image.write(rrset_data);
284 return image.toByteArray();
288 * Given the actual signature and the prototype signature, combine them and
289 * return the fully formed RRSIGRecord.
292 * the cryptographic signature, in DNSSEC format.
294 * the prototype RRSIG RR to add the signature to.
295 * @return the fully formed RRSIG RR.
297 public static RRSIGRecord generateRRSIG(byte[] signature, RRSIGRecord presig) {
298 return new RRSIGRecord(presig.getName(), presig.getDClass(), presig
299 .getTTL(), presig.getTypeCovered(), presig.getAlgorithm(),
300 presig.getOrigTTL(), presig.getExpire(),
301 presig.getTimeSigned(), presig.getFootprint(), presig
302 .getSigner(), signature);
306 * Converts from a RFC 2536 formatted DSA signature to a JCE (ASN.1)
307 * formatted signature.
310 * ASN.1 format = ASN1_SEQ . seq_length . ASN1_INT . Rlength . R . ANS1_INT
314 * The integers R and S may have a leading null byte to force the integer
318 * the RFC 2536 formatted DSA signature.
319 * @return The ASN.1 formatted DSA signature.
320 * @throws SignatureException
321 * if there was something wrong with the RFC 2536 formatted
324 public static byte[] convertDSASignature(byte[] signature)
325 throws SignatureException {
326 if (signature.length != 41) {
327 throw new SignatureException(
328 "RFC 2536 signature not expected length.");
334 // handle initial null byte padding.
335 if (signature[1] < 0) {
339 if (signature[21] < 0) {
343 // ASN.1 length = R length + S length + (2 + 2 + 2), where each 2
344 // is for a ASN.1 type-length byte pair of which there are three
346 byte sig_length = (byte) (40 + r_pad + s_pad + 6);
348 byte[] sig = new byte[sig_length];
351 sig[pos++] = ASN1_SEQ;
352 sig[pos++] = (byte) (sig_length - 2); // all but the SEQ type+length.
353 sig[pos++] = ASN1_INT;
354 sig[pos++] = (byte) (20 + r_pad);
356 // copy the value of R, leaving a null byte if necessary
361 System.arraycopy(signature, 1, sig, pos, 20);
364 sig[pos++] = ASN1_INT;
365 sig[pos++] = (byte) (20 + s_pad);
367 // copy the value of S, leaving a null byte if necessary
372 System.arraycopy(signature, 21, sig, pos, 20);
378 * Converts from a JCE (ASN.1) formatted DSA signature to a RFC 2536
379 * compliant signature.
382 * rfc2536 format = T . R . S
385 * where T is a number between 0 and 8, which is based on the DSA key
386 * length, and R & S are formatted to be exactly 20 bytes each (no leading
390 * the DSA parameters associated with the DSA key used to
391 * generate the signature.
393 * the ASN.1 formatted DSA signature.
394 * @return a RFC 2536 formatted DSA signature.
395 * @throws SignatureException
396 * if something is wrong with the ASN.1 format.
398 public static byte[] convertDSASignature(DSAParams params, byte[] signature)
399 throws SignatureException {
400 if ((signature[0] != ASN1_SEQ) || (signature[2] != ASN1_INT)) {
401 throw new SignatureException(
402 "Invalid ASN.1 signature format: expected SEQ, INT");
405 byte r_pad = (byte) (signature[3] - 20);
407 if (signature[24 + r_pad] != ASN1_INT) {
408 throw new SignatureException(
409 "Invalid ASN.1 signature format: expected SEQ, INT, INT");
412 log.trace("(start) ASN.1 DSA Sig:\n" + base64.toString(signature));
414 byte s_pad = (byte) (signature[25 + r_pad] - 20);
416 byte[] sig = new byte[41]; // all rfc2536 signatures are 41 bytes.
419 sig[0] = (byte) ((params.getP().bitLength() - 512) / 64);
423 System.arraycopy(signature, 4 + r_pad, sig, 1, 20);
425 // R is shorter than 20 bytes, so right justify the number
426 // (r_pad is negative here, remember?).
427 Arrays.fill(sig, 1, 1 - r_pad, (byte) 0);
428 System.arraycopy(signature, 4, sig, 1 - r_pad, 20 + r_pad);
433 System.arraycopy(signature, 26 + r_pad + s_pad, sig, 21, 20);
435 // S is shorter than 20 bytes, so right justify the number
436 // (s_pad is negative here).
437 Arrays.fill(sig, 21, 21 - s_pad, (byte) 0);
439 .arraycopy(signature, 26 + r_pad, sig, 21 - s_pad,
443 if ((r_pad < 0) || (s_pad < 0)) {
445 .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() {
466 public ByteArrayComparator(int offset, boolean debug) {
471 public int compare(byte[] b1, byte[] b2) throws ClassCastException {
472 for (int i = mOffset; (i < b1.length) && (i < b2.length); i++) {
473 if (b1[i] != b2[i]) {
476 .println("offset " + i + " differs (this is "
478 + " bytes in from our offset.)");
481 return (b1[i] & 0xFF) - (b2[i] & 0xFF);
485 return b1.length - b2.length;