2 * ============LICENSE_START====================================================
4 * ===========================================================================
5 * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
6 * Modifications Copyright (C) 2018 IBM.
7 * ===========================================================================
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
12 * http://www.apache.org/licenses/LICENSE-2.0
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 * ============LICENSE_END====================================================
23 package org.onap.aaf.auth.cm.service;
25 import java.io.IOException;
26 import java.net.InetAddress;
27 import java.net.UnknownHostException;
28 import java.nio.ByteBuffer;
29 import java.security.NoSuchAlgorithmException;
30 import java.security.cert.X509Certificate;
31 import java.util.ArrayList;
32 import java.util.Date;
33 import java.util.HashSet;
34 import java.util.List;
37 import org.onap.aaf.auth.cm.AAF_CM;
38 import org.onap.aaf.auth.cm.ca.CA;
39 import org.onap.aaf.auth.cm.ca.X509andChain;
40 import org.onap.aaf.auth.cm.cert.BCFactory;
41 import org.onap.aaf.auth.cm.cert.CSRMeta;
42 import org.onap.aaf.auth.cm.data.CertDrop;
43 import org.onap.aaf.auth.cm.data.CertRenew;
44 import org.onap.aaf.auth.cm.data.CertReq;
45 import org.onap.aaf.auth.cm.data.CertResp;
46 import org.onap.aaf.auth.cm.validation.CertmanValidator;
47 import org.onap.aaf.auth.dao.CassAccess;
48 import org.onap.aaf.auth.dao.cass.ArtiDAO;
49 import org.onap.aaf.auth.dao.cass.CacheInfoDAO;
50 import org.onap.aaf.auth.dao.cass.CertDAO;
51 import org.onap.aaf.auth.dao.cass.CertDAO.Data;
52 import org.onap.aaf.auth.dao.cass.CredDAO;
53 import org.onap.aaf.auth.dao.cass.HistoryDAO;
54 import org.onap.aaf.auth.dao.cass.Status;
55 import org.onap.aaf.auth.dao.hl.Question;
56 import org.onap.aaf.auth.env.AuthzTrans;
57 import org.onap.aaf.auth.layer.Result;
58 import org.onap.aaf.auth.org.Organization;
59 import org.onap.aaf.auth.org.Organization.Identity;
60 import org.onap.aaf.auth.org.OrganizationException;
61 import org.onap.aaf.cadi.Hash;
62 import org.onap.aaf.cadi.Permission;
63 import org.onap.aaf.cadi.Access.Level;
64 import org.onap.aaf.cadi.aaf.AAFPermission;
65 import org.onap.aaf.cadi.config.Config;
66 import org.onap.aaf.cadi.configure.Factory;
67 import org.onap.aaf.cadi.util.FQI;
68 import org.onap.aaf.misc.env.APIException;
69 import org.onap.aaf.misc.env.util.Chrono;
71 public class CMService {
72 // If we add more CAs, may want to parameterize
73 private static final int STD_RENEWAL = 30;
74 private static final int MAX_RENEWAL = 60;
75 private static final int MIN_RENEWAL = 10;
77 public static final String REQUEST = "request";
78 public static final String IGNORE_IPS = "ignoreIPs";
79 public static final String RENEW = "renew";
80 public static final String DROP = "drop";
81 public static final String DOMAIN = "domain";
83 private static final String CERTMAN = "certman";
84 private static final String ACCESS = "access";
86 private static final String[] NO_NOTES = new String[0];
87 private final Permission root_read_permission;
88 private final CertDAO certDAO;
89 private final CredDAO credDAO;
90 private final ArtiDAO artiDAO;
91 private AAF_CM certManager;
92 private Boolean allowIgnoreIPs;
94 // @SuppressWarnings("unchecked")
95 public CMService(final AuthzTrans trans, AAF_CM certman) throws APIException, IOException {
96 // Jonathan 4/2015 SessionFilter unneeded... DataStax already deals with
97 // Multithreading well
99 HistoryDAO hd = new HistoryDAO(trans, certman.cluster, CassAccess.KEYSPACE);
100 CacheInfoDAO cid = new CacheInfoDAO(trans, hd);
101 certDAO = new CertDAO(trans, hd, cid);
102 credDAO = new CredDAO(trans, hd, cid);
103 artiDAO = new ArtiDAO(trans, hd, cid);
105 this.certManager = certman;
107 root_read_permission=new AAFPermission(
108 trans.getProperty(Config.AAF_ROOT_NS, Config.AAF_ROOT_NS_DEF),
113 allowIgnoreIPs = Boolean.valueOf(certman.access.getProperty(Config.CM_ALLOW_IGNORE_IPS, "false"));
115 trans.env().access().log(Level.INIT, "Allowing DNS Evaluation to be turned off with <ns>.certman|<ca name>|"+IGNORE_IPS);
119 public Result<CertResp> requestCert(final AuthzTrans trans, final Result<CertReq> req, final CA ca) {
122 if (req.value.fqdns.isEmpty()) {
123 return Result.err(Result.ERR_BadData, "No Machines passed in Request");
126 String key = req.value.fqdns.get(0);
128 // Policy 6: Requester must be granted Change permission in Namespace requested
129 String mechNS = FQI.reverseDomain(req.value.mechid);
130 if (mechNS == null) {
131 return Result.err(Status.ERR_Denied, "%s does not reflect a valid AAF Namespace", req.value.mechid);
134 List<String> notes = null;
135 List<String> fqdns = new ArrayList<>(req.value.fqdns);
140 Organization org = trans.org();
144 ignoreIPs = trans.fish(new AAFPermission(mechNS,CERTMAN, ca.getName(), IGNORE_IPS));
150 InetAddress primary = null;
151 // Organize incoming information to get to appropriate Artifact
152 if (!fqdns.isEmpty()) {
153 // Accept domain wild cards, but turn into real machines
154 // Need *domain.com:real.machine.domain.com:san.machine.domain.com:...
155 if (fqdns.get(0).startsWith("*")) { // Domain set
156 if (!trans.fish(new AAFPermission(null,ca.getPermType(), ca.getName(), DOMAIN))) {
157 return Result.err(Result.ERR_Denied,
158 "Domain based Authorizations (" + fqdns.get(0) + ") requires Exception");
161 // check for Permission in Add Artifact?
162 String domain = fqdns.get(0).substring(1);
164 if (fqdns.isEmpty()) {
165 return Result.err(Result.ERR_Denied, "Requests using domain require machine declaration");
169 InetAddress ia = InetAddress.getByName(fqdns.get(0));
171 return Result.err(Result.ERR_Denied,
172 "Request not made from matching IP matching domain");
173 } else if (ia.getHostName().endsWith(domain)) {
180 for (String cn : req.value.fqdns) {
182 InetAddress[] ias = InetAddress.getAllByName(cn);
183 Set<String> potentialSanNames = new HashSet<>();
184 for (InetAddress ia1 : ias) {
185 InetAddress ia2 = InetAddress.getByAddress(ia1.getAddress());
186 if (primary == null && ias.length == 1 && trans.ip().equals(ia1.getHostAddress())) {
188 } else if (!cn.equals(ia1.getHostName())
189 && !ia2.getHostName().equals(ia2.getHostAddress())) {
190 potentialSanNames.add(ia1.getHostName());
193 } catch (UnknownHostException e1) {
194 trans.debug().log(e1);
195 return Result.err(Result.ERR_BadData, "There is no DNS lookup for %s", cn);
204 host = req.value.fqdns.get(0);
205 } else if (primary == null) {
206 return Result.err(Result.ERR_Denied, "Request not made from matching IP (%s)", trans.ip());
208 String thost = primary.getHostName();
209 host = thost==null?primary.getHostAddress():thost;
212 ArtiDAO.Data add = null;
213 Result<List<ArtiDAO.Data>> ra = artiDAO.read(trans, req.value.mechid, host);
214 if (ra.isOKhasData()) {
216 add = ra.value.get(0); // single key
219 ra = artiDAO.read(trans, req.value.mechid, key);
220 if (ra.isOKhasData()) { // is the Template available?
221 add = ra.value.get(0);
223 for (String s : fqdns) {
224 if (!s.equals(add.machine)) {
225 add.sans(true).add(s);
228 Result<ArtiDAO.Data> rc = artiDAO.create(trans, add); // Create new Artifact from Template
230 return Result.err(rc);
233 add = ra.value.get(0);
237 // Add Artifact listed FQDNs
238 if (add.sans != null) {
239 for (String s : add.sans) {
240 if (!fqdns.contains(s)) {
246 // Policy 2: If Config marked as Expired, do not create or renew
247 Date now = new Date();
248 if (add.expires != null && now.after(add.expires)) {
249 return Result.err(Result.ERR_Policy, "Configuration for %s %s is expired %s", add.mechid,
250 add.machine, Chrono.dateFmt.format(add.expires));
253 // Policy 3: MechID must be current
254 Identity muser = org.getIdentity(trans, add.mechid);
256 return Result.err(Result.ERR_Policy, "MechID must exist in %s", org.getName());
259 // Policy 4: Sponsor must be current
260 Identity ouser = muser.responsibleTo();
262 return Result.err(Result.ERR_Policy, "%s does not have a current sponsor at %s", add.mechid,
264 } else if (!ouser.isFound() || ouser.mayOwn() != null) {
265 return Result.err(Result.ERR_Policy, "%s reports that %s cannot be responsible for %s",
266 org.getName(), trans.user());
269 // Set Email from most current Sponsor
270 email = ouser.email();
272 // Policy 5: keep Artifact data current
273 if (!ouser.fullID().equals(add.sponsor)) {
274 add.sponsor = ouser.fullID();
275 artiDAO.update(trans, add);
278 // Policy 7: Caller must be the MechID or have specifically delegated
280 if (!(trans.user().equals(req.value.mechid)
281 || trans.fish(new AAFPermission(mechNS,CERTMAN, ca.getName(), REQUEST)))) {
282 return Result.err(Status.ERR_Denied, "%s must have access to modify x509 certs in NS %s",
283 trans.user(), mechNS);
286 // Make sure Primary is the first in fqdns
287 if (fqdns.size() > 1) {
288 for (int i = 0; i < fqdns.size(); ++i) {
289 if (primary==null && !ignoreIPs) {
290 trans.error().log("CMService var primary is null");
292 String fg = fqdns.get(i);
293 if (fg!=null && fg.equals(primary.getHostName())) {
295 String tmp = fqdns.get(0);
296 fqdns.set(0, primary.getHostName());
303 } catch (Exception e) {
304 trans.debug().log(e);
305 return Result.err(Status.ERR_Denied,
306 "AppID Sponsorship cannot be determined at this time. Try later.");
311 csrMeta = BCFactory.createCSRMeta(ca, req.value.mechid, email, fqdns);
312 csrMeta.environment(ca.getEnv());
313 X509andChain x509ac = ca.sign(trans, csrMeta);
314 if (x509ac == null) {
315 return Result.err(Result.ERR_ActionNotCompleted, "x509 Certificate not signed by CA");
317 trans.info().printf("X509 Subject: %s", x509ac.getX509().getSubjectDN());
319 X509Certificate x509 = x509ac.getX509();
320 CertDAO.Data cdd = new CertDAO.Data();
321 cdd.ca = ca.getName();
322 cdd.serial = x509.getSerialNumber();
323 cdd.id = req.value.mechid;
324 cdd.x500 = x509.getSubjectDN().getName();
325 cdd.x509 = Factory.toString(trans, x509);
326 certDAO.create(trans, cdd);
328 CredDAO.Data crdd = new CredDAO.Data();
329 crdd.other = Question.random.nextInt();
330 crdd.cred = getChallenge256SaltedHash(csrMeta.challenge(), crdd.other);
331 crdd.expires = x509.getNotAfter();
332 crdd.id = req.value.mechid;
333 crdd.ns = Question.domain2ns(crdd.id);
334 crdd.type = CredDAO.CERT_SHA256_RSA;
335 crdd.tag = cdd.serial.toString(16);
336 credDAO.create(trans, crdd);
338 CertResp cr = new CertResp(trans, ca, x509, csrMeta, x509ac.getTrustChain(), compileNotes(notes));
339 return Result.ok(cr);
340 } catch (Exception e) {
341 trans.debug().log(e);
342 return Result.err(Result.ERR_ActionNotCompleted, e.getMessage());
345 return Result.err(req);
349 public Result<CertResp> renewCert(AuthzTrans trans, Result<CertRenew> renew) {
351 return Result.err(Result.ERR_NotImplemented, "Not implemented yet");
353 return Result.err(renew);
357 public Result<Void> dropCert(AuthzTrans trans, Result<CertDrop> drop) {
359 return Result.err(Result.ERR_NotImplemented, "Not implemented yet");
361 return Result.err(drop);
365 public Result<List<Data>> readCertsByMechID(AuthzTrans trans, String mechID) {
366 // Policy 1: To Read, must have NS Read or is Sponsor
367 String ns = Question.domain2ns(mechID);
369 if (trans.user().equals(mechID) || trans.fish(new AAFPermission(ns,ACCESS, "*", "read"))
370 || (trans.org().validate(trans, Organization.Policy.OWNS_MECHID, null, mechID)) == null) {
371 return certDAO.readID(trans, mechID);
373 return Result.err(Result.ERR_Denied, "%s is not the ID, Sponsor or NS Owner/Admin for %s at %s",
374 trans.user(), mechID, trans.org().getName());
376 } catch (OrganizationException e) {
377 return Result.err(e);
381 public Result<CertResp> requestPersonalCert(AuthzTrans trans, CA ca) {
382 if (ca.inPersonalDomains(trans.getUserPrincipal())) {
383 Organization org = trans.org();
385 // Policy 1: MechID must be current
388 ouser = org.getIdentity(trans, trans.user());
389 } catch (OrganizationException e1) {
390 trans.debug().log(e1);
394 return Result.err(Result.ERR_Policy, "Requesting User must exist in %s", org.getName());
397 // Set Email from most current Sponsor
401 csrMeta = BCFactory.createPersonalCSRMeta(ca, trans.user(), ouser.email());
402 X509andChain x509ac = ca.sign(trans, csrMeta);
403 if (x509ac == null) {
404 return Result.err(Result.ERR_ActionNotCompleted, "x509 Certificate not signed by CA");
406 X509Certificate x509 = x509ac.getX509();
407 CertDAO.Data cdd = new CertDAO.Data();
408 cdd.ca = ca.getName();
409 cdd.serial = x509.getSerialNumber();
410 cdd.id = trans.user();
411 cdd.x500 = x509.getSubjectDN().getName();
412 cdd.x509 = Factory.toString(trans, x509);
413 certDAO.create(trans, cdd);
415 CertResp cr = new CertResp(trans, ca, x509, csrMeta, x509ac.getTrustChain(), compileNotes(null));
416 return Result.ok(cr);
417 } catch (Exception e) {
418 trans.debug().log(e);
419 return Result.err(Result.ERR_ActionNotCompleted, e.getMessage());
422 return Result.err(Result.ERR_Denied, trans.user(), " not supported for CA", ca.getName());
429 public Result<Void> createArtifact(AuthzTrans trans, List<ArtiDAO.Data> list) {
430 CertmanValidator v = new CertmanValidator().artisRequired(list, 1);
432 return Result.err(Result.ERR_BadData, v.errs());
434 for (ArtiDAO.Data add : list) {
436 // Policy 1: MechID must exist in Org
437 Identity muser = trans.org().getIdentity(trans, add.mechid);
439 return Result.err(Result.ERR_Denied, "%s is not valid for %s", add.mechid, trans.org().getName());
442 // Policy 2: MechID must have valid Organization Owner
444 if (muser.isPerson()) {
447 Identity ouser = muser.responsibleTo();
449 return Result.err(Result.ERR_Denied, "%s is not a valid Sponsor for %s at %s", trans.user(),
450 add.mechid, trans.org().getName());
453 // Policy 3: Calling ID must be MechID Owner
454 if (!trans.user().startsWith(ouser.id())) {
455 return Result.err(Result.ERR_Denied, "%s is not the Sponsor for %s at %s", trans.user(),
456 add.mechid, trans.org().getName());
461 // Policy 4: Renewal Days are between 10 and 60 (constants, may be
463 if (add.renewDays < MIN_RENEWAL) {
464 add.renewDays = STD_RENEWAL;
465 } else if (add.renewDays > MAX_RENEWAL) {
466 add.renewDays = MAX_RENEWAL;
469 // Policy 5: If Notify is blank, set to Owner's Email
470 if (add.notify == null || add.notify.length() == 0) {
471 add.notify = "mailto:" + emailUser.email();
474 // Policy 6: Only do Domain by Exception
475 if (add.machine.startsWith("*")) { // Domain set
476 CA ca = certManager.getCA(add.ca);
478 if (!trans.fish(new AAFPermission(ca.getPermNS(),ca.getPermType(), add.ca, DOMAIN))) {
479 return Result.err(Result.ERR_Denied, "Domain Artifacts (%s) requires specific Permission",
484 // Set Sponsor from Golden Source
485 add.sponsor = emailUser.fullID();
487 } catch (OrganizationException e) {
488 return Result.err(e);
491 Result<ArtiDAO.Data> rv = artiDAO.create(trans, add);
492 // come up with Partial Reporting Scheme, or allow only one at a time.
494 return Result.err(rv);
500 public Result<List<ArtiDAO.Data>> readArtifacts(AuthzTrans trans, ArtiDAO.Data add) throws OrganizationException {
501 CertmanValidator v = new CertmanValidator().keys(add);
503 return Result.err(Result.ERR_BadData, v.errs());
505 Result<List<ArtiDAO.Data>> data = artiDAO.read(trans, add);
506 if (data.notOKorIsEmpty()) {
509 add = data.value.get(0);
510 if (trans.user().equals(add.mechid)
511 || trans.fish(root_read_permission,
512 new AAFPermission(add.ns,ACCESS, "*", "read"),
513 new AAFPermission(add.ns,CERTMAN, add.ca, "read"),
514 new AAFPermission(add.ns,CERTMAN, add.ca, REQUEST))
515 || (trans.org().validate(trans, Organization.Policy.OWNS_MECHID, null, add.mechid)) == null) {
518 return Result.err(Result.ERR_Denied,
519 "%s is not %s, is not the sponsor, and doesn't have delegated permission.", trans.user(),
520 add.mechid, add.ns + ".certman|" + add.ca + "|read or ...|request"); // note: reason is set by 2nd
521 // case, if 1st case misses
526 public Result<List<ArtiDAO.Data>> readArtifactsByMechID(AuthzTrans trans, String mechid)
527 throws OrganizationException {
528 CertmanValidator v = new CertmanValidator();
529 v.nullOrBlank("mechid", mechid);
531 return Result.err(Result.ERR_BadData, v.errs());
533 String ns = FQI.reverseDomain(mechid);
536 if (trans.fish(new AAFPermission(ns, ACCESS, "*", "read"))
537 || (reason = trans.org().validate(trans, Organization.Policy.OWNS_MECHID, null, mechid)) == null) {
538 return artiDAO.readByMechID(trans, mechid);
540 return Result.err(Result.ERR_Denied, reason); // note: reason is set by 2nd case, if 1st case misses
545 public Result<List<ArtiDAO.Data>> readArtifactsByMachine(AuthzTrans trans, String machine) {
546 CertmanValidator v = new CertmanValidator();
547 v.nullOrBlank("machine", machine);
549 return Result.err(Result.ERR_BadData, v.errs());
554 return artiDAO.readByMachine(trans, machine);
557 public Result<List<ArtiDAO.Data>> readArtifactsByNs(AuthzTrans trans, String ns) {
558 CertmanValidator v = new CertmanValidator();
559 v.nullOrBlank("ns", ns);
561 return Result.err(Result.ERR_BadData, v.errs());
565 return artiDAO.readByNs(trans, ns);
568 public Result<Void> updateArtifact(AuthzTrans trans, List<ArtiDAO.Data> list) throws OrganizationException {
569 CertmanValidator v = new CertmanValidator();
570 v.artisRequired(list, 1);
572 return Result.err(Result.ERR_BadData, v.errs());
575 // Check if requesting User is Sponsor
576 // Shall we do one, or multiples?
577 for (ArtiDAO.Data add : list) {
578 // Policy 1: MechID must exist in Org
579 Identity muser = trans.org().getIdentity(trans, add.mechid);
581 return Result.err(Result.ERR_Denied, "%s is not valid for %s", add.mechid, trans.org().getName());
584 // Policy 2: MechID must have valid Organization Owner
585 Identity ouser = muser.responsibleTo();
587 return Result.err(Result.ERR_Denied, "%s is not a valid Sponsor for %s at %s", trans.user(), add.mechid,
588 trans.org().getName());
591 // Policy 3: Renewal Days are between 10 and 60 (constants, may be
593 if (add.renewDays < MIN_RENEWAL) {
594 add.renewDays = STD_RENEWAL;
595 } else if (add.renewDays > MAX_RENEWAL) {
596 add.renewDays = MAX_RENEWAL;
599 // Policy 4: Data is always updated with the latest Sponsor
600 // Add to Sponsor, to make sure we are always up to date.
601 add.sponsor = ouser.fullID();
603 // Policy 5: If Notify is blank, set to Owner's Email
604 if (add.notify == null || add.notify.length() == 0) {
605 add.notify = "mailto:" + ouser.email();
607 // Policy 6: Only do Domain by Exception
608 if (add.machine.startsWith("*")) { // Domain set
609 CA ca = certManager.getCA(add.ca);
611 return Result.err(Result.ERR_BadData, "CA is required in Artifact");
613 if (!trans.fish(new AAFPermission(null,ca.getPermType(), add.ca, DOMAIN))) {
614 return Result.err(Result.ERR_Denied, "Domain Artifacts (%s) requires specific Permission",
619 // Policy 7: only Owner may update info
620 if (trans.user().startsWith(ouser.id())) {
621 return artiDAO.update(trans, add);
623 return Result.err(Result.ERR_Denied, "%s may not update info for %s", trans.user(), muser.fullID());
626 return Result.err(Result.ERR_BadData, "No Artifacts to update");
629 public Result<Void> deleteArtifact(AuthzTrans trans, String mechid, String machine) throws OrganizationException {
630 CertmanValidator v = new CertmanValidator();
631 v.nullOrBlank("mechid", mechid).nullOrBlank("machine", machine);
633 return Result.err(Result.ERR_BadData, v.errs());
636 Result<List<ArtiDAO.Data>> rlad = artiDAO.read(trans, mechid, machine);
637 if (rlad.notOKorIsEmpty()) {
638 return Result.err(Result.ERR_NotFound, "Artifact for %s %s does not exist.", mechid, machine);
641 return deleteArtifact(trans, rlad.value.get(0));
644 private Result<Void> deleteArtifact(AuthzTrans trans, ArtiDAO.Data add) throws OrganizationException {
645 // Policy 1: Record should be delete able only by Existing Sponsor.
646 String sponsor = null;
647 Identity muser = trans.org().getIdentity(trans, add.mechid);
649 Identity ouser = muser.responsibleTo();
651 sponsor = ouser.fullID();
654 // Policy 1.a: If Sponsorship is deleted in system of Record, then
655 // accept deletion by sponsor in Artifact Table
656 if (sponsor == null) {
657 sponsor = add.sponsor;
660 String ns = FQI.reverseDomain(add.mechid);
662 if (trans.fish(new AAFPermission(ns,ACCESS, "*", "write")) || trans.user().equals(sponsor)) {
663 return artiDAO.delete(trans, add, false);
665 return Result.err(Result.ERR_Denied, "%1 is not allowed to delete this item", trans.user());
668 public Result<Void> deleteArtifact(AuthzTrans trans, List<ArtiDAO.Data> list) {
669 CertmanValidator v = new CertmanValidator().artisRequired(list, 1);
671 return Result.err(Result.ERR_BadData, v.errs());
675 boolean partial = false;
676 Result<Void> result = null;
677 for (ArtiDAO.Data add : list) {
678 result = deleteArtifact(trans, add);
679 if (result.notOK()) {
683 if (result == null) {
684 result = Result.err(Result.ERR_BadData, "No Artifacts to delete");
685 } else if (partial) {
686 result.partialContent(true);
689 } catch (Exception e) {
690 return Result.err(e);
694 private String[] compileNotes(List<String> notes) {
699 rv = new String[notes.size()];
705 private ByteBuffer getChallenge256SaltedHash(String challenge, int salt) throws NoSuchAlgorithmException {
706 ByteBuffer bb = ByteBuffer.allocate(Integer.SIZE + challenge.length());
708 bb.put(challenge.getBytes());
709 byte[] hash = Hash.hashSHA256(bb.array());
710 return ByteBuffer.wrap(hash);