Line data Source code
1 : /*
2 : *
3 : * Copyright (c) 2021-2022 Project CHIP Authors
4 : * All rights reserved.
5 : *
6 : * Licensed under the Apache License, Version 2.0 (the "License");
7 : * you may not use this file except in compliance with the License.
8 : * You may obtain a copy of the License at
9 : *
10 : * http://www.apache.org/licenses/LICENSE-2.0
11 : *
12 : * Unless required by applicable law or agreed to in writing, software
13 : * distributed under the License is distributed on an "AS IS" BASIS,
14 : * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 : * See the License for the specific language governing permissions and
16 : * limitations under the License.
17 : */
18 :
19 : /**
20 : * @file
21 : * This file implements methods for generating CHIP X.509 certificate.
22 : *
23 : */
24 :
25 : #include <algorithm>
26 : #include <initializer_list>
27 : #include <inttypes.h>
28 : #include <stddef.h>
29 :
30 : #include <credentials/CHIPCert_Internal.h>
31 : #include <lib/asn1/ASN1.h>
32 : #include <lib/asn1/ASN1Macros.h>
33 : #include <lib/core/CHIPCore.h>
34 : #include <lib/core/CHIPSafeCasts.h>
35 : #include <lib/support/CodeUtils.h>
36 : #include <lib/support/DLLUtil.h>
37 : #include <protocols/Protocols.h>
38 :
39 : namespace chip {
40 : namespace Credentials {
41 :
42 : using namespace chip::ASN1;
43 : using namespace chip::Crypto;
44 : using namespace chip::Protocols;
45 :
46 : namespace {
47 :
48 : enum IsCACert
49 : {
50 : kCACert,
51 : kNotCACert,
52 : };
53 :
54 211 : CHIP_ERROR EncodeSubjectPublicKeyInfo(const Crypto::P256PublicKey & pubkey, ASN1Writer & writer)
55 : {
56 211 : CHIP_ERROR err = CHIP_NO_ERROR;
57 :
58 211 : ASN1_START_SEQUENCE
59 : {
60 211 : ASN1_START_SEQUENCE
61 : {
62 211 : ASN1_ENCODE_OBJECT_ID(kOID_PubKeyAlgo_ECPublicKey);
63 211 : ASN1_ENCODE_OBJECT_ID(kOID_EllipticCurve_prime256v1);
64 : }
65 211 : ASN1_END_SEQUENCE;
66 :
67 211 : ReturnErrorOnFailure(writer.PutBitString(0, pubkey, static_cast<uint8_t>(pubkey.Length())));
68 : }
69 211 : ASN1_END_SEQUENCE;
70 :
71 211 : exit:
72 211 : return err;
73 : }
74 :
75 206 : CHIP_ERROR EncodeAuthorityKeyIdentifierExtension(const Crypto::P256PublicKey & pubkey, ASN1Writer & writer)
76 : {
77 206 : CHIP_ERROR err = CHIP_NO_ERROR;
78 :
79 206 : ASN1_START_SEQUENCE
80 : {
81 206 : ASN1_ENCODE_OBJECT_ID(kOID_Extension_AuthorityKeyIdentifier);
82 :
83 206 : ASN1_START_OCTET_STRING_ENCAPSULATED
84 : {
85 206 : ASN1_START_SEQUENCE
86 : {
87 : uint8_t keyid[kSHA1_Hash_Length];
88 206 : ReturnErrorOnFailure(Crypto::Hash_SHA1(pubkey, pubkey.Length(), keyid));
89 :
90 206 : ReturnErrorOnFailure(
91 : writer.PutOctetString(kASN1TagClass_ContextSpecific, 0, keyid, static_cast<uint8_t>(sizeof(keyid))));
92 : }
93 206 : ASN1_END_SEQUENCE;
94 : }
95 206 : ASN1_END_ENCAPSULATED;
96 : }
97 206 : ASN1_END_SEQUENCE;
98 :
99 206 : exit:
100 206 : return err;
101 : }
102 :
103 206 : CHIP_ERROR EncodeSubjectKeyIdentifierExtension(const Crypto::P256PublicKey & pubkey, ASN1Writer & writer)
104 : {
105 206 : CHIP_ERROR err = CHIP_NO_ERROR;
106 :
107 206 : ASN1_START_SEQUENCE
108 : {
109 206 : ASN1_ENCODE_OBJECT_ID(kOID_Extension_SubjectKeyIdentifier);
110 :
111 206 : ASN1_START_OCTET_STRING_ENCAPSULATED
112 : {
113 : uint8_t keyid[kSHA1_Hash_Length];
114 206 : ReturnErrorOnFailure(Crypto::Hash_SHA1(pubkey, pubkey.Length(), keyid));
115 :
116 206 : ReturnErrorOnFailure(writer.PutOctetString(keyid, static_cast<uint8_t>(sizeof(keyid))));
117 : }
118 206 : ASN1_END_ENCAPSULATED;
119 : }
120 206 : ASN1_END_SEQUENCE;
121 :
122 206 : exit:
123 206 : return err;
124 : }
125 :
126 91 : CHIP_ERROR EncodeExtKeyUsageExtension(std::initializer_list<OID> keyPurposeOIDs, ASN1Writer & writer)
127 : {
128 91 : CHIP_ERROR err = CHIP_NO_ERROR;
129 91 : ASN1_START_SEQUENCE
130 : {
131 91 : ASN1_ENCODE_OBJECT_ID(kOID_Extension_ExtendedKeyUsage);
132 :
133 : // ExtKeyUsage extension MUST be marked as critical.
134 91 : ASN1_ENCODE_BOOLEAN(true);
135 91 : ASN1_START_OCTET_STRING_ENCAPSULATED
136 : {
137 91 : ASN1_START_SEQUENCE
138 : {
139 273 : for (auto && oid : keyPurposeOIDs)
140 : {
141 182 : ASN1_ENCODE_OBJECT_ID(oid);
142 : }
143 : }
144 91 : ASN1_END_SEQUENCE;
145 : }
146 91 : ASN1_END_ENCAPSULATED;
147 : }
148 91 : ASN1_END_SEQUENCE;
149 :
150 91 : exit:
151 91 : return err;
152 : }
153 :
154 211 : CHIP_ERROR EncodeKeyUsageExtension(BitFlags<KeyUsageFlags> keyUsageFlags, ASN1Writer & writer)
155 : {
156 211 : CHIP_ERROR err = CHIP_NO_ERROR;
157 211 : ASN1_START_SEQUENCE
158 : {
159 211 : ASN1_ENCODE_OBJECT_ID(kOID_Extension_KeyUsage);
160 :
161 : // KeyUsage extension MUST be marked as critical.
162 211 : ASN1_ENCODE_BOOLEAN(true);
163 211 : ASN1_START_OCTET_STRING_ENCAPSULATED
164 : {
165 211 : ASN1_ENCODE_BIT_STRING(keyUsageFlags.Raw());
166 : }
167 211 : ASN1_END_ENCAPSULATED;
168 : }
169 211 : ASN1_END_SEQUENCE;
170 :
171 211 : exit:
172 211 : return err;
173 : }
174 :
175 211 : CHIP_ERROR EncodeIsCAExtension(IsCACert isCA, ASN1Writer & writer)
176 : {
177 211 : CHIP_ERROR err = CHIP_NO_ERROR;
178 211 : ASN1_START_SEQUENCE
179 : {
180 211 : ASN1_ENCODE_OBJECT_ID(kOID_Extension_BasicConstraints);
181 :
182 : // BasicConstraints extension MUST be marked as critical.
183 211 : ASN1_ENCODE_BOOLEAN(true);
184 :
185 211 : ASN1_START_OCTET_STRING_ENCAPSULATED
186 : {
187 211 : ASN1_START_SEQUENCE
188 : {
189 : // cA BOOLEAN
190 211 : if (isCA == kCACert)
191 : {
192 : // Encode the boolean only if isCA is true
193 116 : ASN1_ENCODE_BOOLEAN(true);
194 : }
195 : }
196 211 : ASN1_END_SEQUENCE;
197 : }
198 211 : ASN1_END_ENCAPSULATED;
199 : }
200 211 : ASN1_END_SEQUENCE;
201 :
202 211 : exit:
203 211 : return err;
204 : }
205 :
206 116 : CHIP_ERROR EncodeCASpecificExtensions(ASN1Writer & writer)
207 : {
208 116 : ReturnErrorOnFailure(EncodeIsCAExtension(kCACert, writer));
209 116 : ReturnErrorOnFailure(
210 : EncodeKeyUsageExtension(BitFlags<KeyUsageFlags>(KeyUsageFlags::kKeyCertSign, KeyUsageFlags::kCRLSign), writer));
211 116 : return CHIP_NO_ERROR;
212 : }
213 :
214 86 : CHIP_ERROR EncodeNOCSpecificExtensions(ASN1Writer & writer)
215 : {
216 86 : ReturnErrorOnFailure(EncodeIsCAExtension(kNotCACert, writer));
217 86 : ReturnErrorOnFailure(EncodeKeyUsageExtension(KeyUsageFlags::kDigitalSignature, writer));
218 86 : ReturnErrorOnFailure(EncodeExtKeyUsageExtension({ kOID_KeyPurpose_ClientAuth, kOID_KeyPurpose_ServerAuth }, writer));
219 86 : return CHIP_NO_ERROR;
220 : }
221 :
222 4 : CHIP_ERROR EncodeVendorIdVerificationSignerSpecificExtensions(ASN1Writer & writer)
223 : {
224 4 : ReturnErrorOnFailure(EncodeIsCAExtension(kNotCACert, writer));
225 4 : ReturnErrorOnFailure(EncodeKeyUsageExtension(KeyUsageFlags::kDigitalSignature, writer));
226 4 : return CHIP_NO_ERROR;
227 : }
228 :
229 206 : CHIP_ERROR EncodeFutureExtension(const Optional<FutureExtension> & futureExt, ASN1Writer & writer)
230 : {
231 206 : CHIP_ERROR err = CHIP_NO_ERROR;
232 :
233 206 : VerifyOrReturnError(futureExt.HasValue(), CHIP_NO_ERROR);
234 :
235 14 : ASN1_START_SEQUENCE
236 : {
237 14 : ReturnErrorOnFailure(writer.PutObjectId(futureExt.Value().OID.data(), static_cast<uint16_t>(futureExt.Value().OID.size())));
238 :
239 14 : ASN1_START_OCTET_STRING_ENCAPSULATED
240 : {
241 14 : ReturnErrorOnFailure(writer.PutOctetString(futureExt.Value().Extension.data(),
242 : static_cast<uint16_t>(futureExt.Value().Extension.size())));
243 : }
244 14 : ASN1_END_ENCAPSULATED;
245 : }
246 14 : ASN1_END_SEQUENCE;
247 :
248 14 : exit:
249 14 : return err;
250 : }
251 :
252 206 : CHIP_ERROR EncodeExtensions(CertType certType, const Crypto::P256PublicKey & SKI, const Crypto::P256PublicKey & AKI,
253 : const Optional<FutureExtension> & futureExt, ASN1Writer & writer)
254 : {
255 206 : CHIP_ERROR err = CHIP_NO_ERROR;
256 :
257 206 : ASN1_START_CONSTRUCTED(kASN1TagClass_ContextSpecific, 3)
258 : {
259 206 : ASN1_START_SEQUENCE
260 : {
261 206 : switch (certType)
262 : {
263 116 : case CertType::kICA:
264 : case CertType::kRoot: {
265 116 : ReturnErrorOnFailure(EncodeCASpecificExtensions(writer));
266 116 : break;
267 : }
268 86 : case CertType::kNode: {
269 86 : ReturnErrorOnFailure(EncodeNOCSpecificExtensions(writer));
270 86 : break;
271 : }
272 4 : case CertType::kVidVerificationSigner: {
273 4 : ReturnErrorOnFailure(EncodeVendorIdVerificationSignerSpecificExtensions(writer));
274 4 : break;
275 : }
276 0 : case CertType::kFirmwareSigning:
277 : case CertType::kNetworkIdentity: {
278 : // Nothing to encode extra for those.
279 0 : break;
280 : }
281 0 : default: {
282 : // Unknown/invalid certificate type should not happen.
283 0 : return CHIP_ERROR_INVALID_ARGUMENT;
284 : }
285 : }
286 206 : ReturnErrorOnFailure(EncodeSubjectKeyIdentifierExtension(SKI, writer));
287 :
288 206 : ReturnErrorOnFailure(EncodeAuthorityKeyIdentifierExtension(AKI, writer));
289 :
290 206 : ReturnErrorOnFailure(EncodeFutureExtension(futureExt, writer));
291 : }
292 206 : ASN1_END_SEQUENCE;
293 : }
294 206 : ASN1_END_CONSTRUCTED;
295 :
296 206 : exit:
297 206 : return err;
298 : }
299 :
300 211 : CHIP_ERROR EncodeValidity(uint32_t validityStart, uint32_t validityEnd, ASN1Writer & writer)
301 : {
302 211 : CHIP_ERROR err = CHIP_NO_ERROR;
303 : ASN1UniversalTime asn1Time;
304 :
305 211 : ASN1_START_SEQUENCE
306 : {
307 211 : ReturnErrorOnFailure(ChipEpochToASN1Time(validityStart, asn1Time));
308 211 : ASN1_ENCODE_TIME(asn1Time);
309 :
310 211 : ReturnErrorOnFailure(ChipEpochToASN1Time(validityEnd, asn1Time));
311 211 : ASN1_ENCODE_TIME(asn1Time);
312 : }
313 211 : ASN1_END_SEQUENCE;
314 :
315 211 : exit:
316 211 : return err;
317 : }
318 :
319 103 : CHIP_ERROR EncodeChipECDSASignature(Crypto::P256ECDSASignature & signature, ASN1Writer & writer)
320 : {
321 103 : CHIP_ERROR err = CHIP_NO_ERROR;
322 :
323 103 : ASN1_START_BIT_STRING_ENCAPSULATED
324 : {
325 : // Convert RAW signature to DER when generating X509 certs.
326 103 : P256ECDSASignatureSpan raw_sig(signature.Bytes());
327 103 : ReturnErrorOnFailure(ConvertECDSASignatureRawToDER(raw_sig, writer));
328 : }
329 103 : ASN1_END_ENCAPSULATED;
330 :
331 103 : exit:
332 103 : return err;
333 : }
334 :
335 209 : CHIP_ERROR EncodeTBSCert(const X509CertRequestParams & requestParams, const Crypto::P256PublicKey & subjectPubkey,
336 : const Crypto::P256PublicKey & issuerPubkey, ASN1Writer & writer)
337 : {
338 209 : CHIP_ERROR err = CHIP_NO_ERROR;
339 : CertType certType;
340 :
341 209 : VerifyOrReturnError(requestParams.SerialNumber >= 0, CHIP_ERROR_INVALID_ARGUMENT);
342 206 : VerifyOrReturnError(requestParams.ValidityEnd == kNullCertTime || requestParams.ValidityEnd >= requestParams.ValidityStart,
343 : CHIP_ERROR_INVALID_ARGUMENT);
344 :
345 206 : ReturnErrorOnFailure(requestParams.SubjectDN.GetCertType(certType));
346 :
347 206 : ASN1_START_SEQUENCE
348 : {
349 : // version [0] EXPLICIT Version DEFAULT v1
350 206 : ASN1_START_CONSTRUCTED(kASN1TagClass_ContextSpecific, 0)
351 : {
352 : // Version ::= INTEGER { v1(0), v2(1), v3(2) }
353 206 : ASN1_ENCODE_INTEGER(2);
354 : }
355 206 : ASN1_END_CONSTRUCTED;
356 :
357 206 : ReturnErrorOnFailure(writer.PutInteger(requestParams.SerialNumber));
358 :
359 206 : ASN1_START_SEQUENCE
360 : {
361 206 : ASN1_ENCODE_OBJECT_ID(kOID_SigAlgo_ECDSAWithSHA256);
362 : }
363 206 : ASN1_END_SEQUENCE;
364 :
365 : // issuer Name
366 206 : ReturnErrorOnFailure(requestParams.IssuerDN.EncodeToASN1(writer));
367 :
368 : // validity Validity,
369 206 : ReturnErrorOnFailure(EncodeValidity(requestParams.ValidityStart, requestParams.ValidityEnd, writer));
370 :
371 : // subject Name
372 206 : ReturnErrorOnFailure(requestParams.SubjectDN.EncodeToASN1(writer));
373 :
374 206 : ReturnErrorOnFailure(EncodeSubjectPublicKeyInfo(subjectPubkey, writer));
375 :
376 : // certificate extensions
377 206 : ReturnErrorOnFailure(EncodeExtensions(certType, subjectPubkey, issuerPubkey, requestParams.FutureExt, writer));
378 : }
379 206 : ASN1_END_SEQUENCE;
380 :
381 206 : exit:
382 206 : return err;
383 : }
384 :
385 : } // namespace
386 :
387 5 : CHIP_ERROR EncodeNetworkIdentityTBSCert(const P256PublicKey & pubkey, ASN1Writer & writer)
388 : {
389 5 : CHIP_ERROR err = CHIP_NO_ERROR;
390 5 : ChipDN issuerAndSubject;
391 5 : InitNetworkIdentitySubject(issuerAndSubject);
392 :
393 5 : ASN1_START_SEQUENCE
394 : {
395 : // version [0] EXPLICIT Version DEFAULT v1
396 5 : ASN1_START_CONSTRUCTED(kASN1TagClass_ContextSpecific, 0)
397 : {
398 5 : ASN1_ENCODE_INTEGER(2); // Version ::= INTEGER { v1(0), v2(1), v3(2) }
399 : }
400 5 : ASN1_END_CONSTRUCTED;
401 :
402 5 : ReturnErrorOnFailure(writer.PutInteger(kNetworkIdentitySerialNumber));
403 :
404 5 : ASN1_START_SEQUENCE
405 : {
406 5 : ASN1_ENCODE_OBJECT_ID(kOID_SigAlgo_ECDSAWithSHA256);
407 : }
408 5 : ASN1_END_SEQUENCE;
409 :
410 : // issuer Name
411 5 : ReturnErrorOnFailure(issuerAndSubject.EncodeToASN1(writer));
412 :
413 : // validity Validity,
414 5 : ReturnErrorOnFailure(EncodeValidity(kNetworkIdentityNotBeforeTime, kNetworkIdentityNotAfterTime, writer));
415 :
416 : // subject Name
417 5 : ReturnErrorOnFailure(issuerAndSubject.EncodeToASN1(writer));
418 :
419 5 : ReturnErrorOnFailure(EncodeSubjectPublicKeyInfo(pubkey, writer));
420 :
421 : // certificate extensions
422 5 : ASN1_START_CONSTRUCTED(kASN1TagClass_ContextSpecific, 3)
423 : {
424 5 : ASN1_START_SEQUENCE
425 : {
426 5 : EncodeIsCAExtension(kNotCACert, writer);
427 5 : EncodeKeyUsageExtension(KeyUsageFlags::kDigitalSignature, writer);
428 5 : EncodeExtKeyUsageExtension({ kOID_KeyPurpose_ClientAuth, kOID_KeyPurpose_ServerAuth }, writer);
429 : }
430 5 : ASN1_END_SEQUENCE;
431 : }
432 5 : ASN1_END_CONSTRUCTED;
433 : }
434 5 : ASN1_END_SEQUENCE;
435 :
436 5 : exit:
437 5 : return err;
438 5 : }
439 :
440 106 : CHIP_ERROR NewChipX509Cert(const X509CertRequestParams & requestParams, const Crypto::P256PublicKey & subjectPubkey,
441 : const Crypto::P256Keypair & issuerKeypair, MutableByteSpan & x509Cert)
442 : {
443 106 : CHIP_ERROR err = CHIP_NO_ERROR;
444 : ASN1Writer writer;
445 106 : writer.Init(x509Cert);
446 :
447 106 : ReturnErrorOnFailure(EncodeTBSCert(requestParams, subjectPubkey, issuerKeypair.Pubkey(), writer));
448 :
449 103 : Crypto::P256ECDSASignature signature;
450 103 : ReturnErrorOnFailure(issuerKeypair.ECDSA_sign_msg(x509Cert.data(), writer.GetLengthWritten(), signature));
451 :
452 103 : writer.Init(x509Cert);
453 :
454 103 : ASN1_START_SEQUENCE
455 : {
456 103 : ReturnErrorOnFailure(EncodeTBSCert(requestParams, subjectPubkey, issuerKeypair.Pubkey(), writer));
457 :
458 103 : ASN1_START_SEQUENCE
459 : {
460 103 : ASN1_ENCODE_OBJECT_ID(kOID_SigAlgo_ECDSAWithSHA256);
461 : }
462 103 : ASN1_END_SEQUENCE;
463 :
464 103 : ReturnErrorOnFailure(EncodeChipECDSASignature(signature, writer));
465 : }
466 103 : ASN1_END_SEQUENCE;
467 :
468 103 : x509Cert.reduce_size(writer.GetLengthWritten());
469 :
470 103 : exit:
471 103 : return err;
472 103 : }
473 :
474 33 : DLL_EXPORT CHIP_ERROR NewRootX509Cert(const X509CertRequestParams & requestParams, const Crypto::P256Keypair & issuerKeypair,
475 : MutableByteSpan & x509Cert)
476 : {
477 : CertType certType;
478 :
479 33 : ReturnErrorOnFailure(requestParams.SubjectDN.GetCertType(certType));
480 33 : VerifyOrReturnError(certType == CertType::kRoot, CHIP_ERROR_INVALID_ARGUMENT);
481 32 : VerifyOrReturnError(requestParams.SubjectDN.IsEqual(requestParams.IssuerDN), CHIP_ERROR_INVALID_ARGUMENT);
482 :
483 31 : return NewChipX509Cert(requestParams, issuerKeypair.Pubkey(), issuerKeypair, x509Cert);
484 : }
485 :
486 30 : DLL_EXPORT CHIP_ERROR NewICAX509Cert(const X509CertRequestParams & requestParams, const Crypto::P256PublicKey & subjectPubkey,
487 : const Crypto::P256Keypair & issuerKeypair, MutableByteSpan & x509Cert)
488 : {
489 : CertType certType;
490 :
491 30 : ReturnErrorOnFailure(requestParams.SubjectDN.GetCertType(certType));
492 30 : VerifyOrReturnError(certType == CertType::kICA, CHIP_ERROR_INVALID_ARGUMENT);
493 :
494 29 : ReturnErrorOnFailure(requestParams.IssuerDN.GetCertType(certType));
495 29 : VerifyOrReturnError(certType == CertType::kRoot, CHIP_ERROR_INVALID_ARGUMENT);
496 :
497 29 : return NewChipX509Cert(requestParams, subjectPubkey, issuerKeypair, x509Cert);
498 : }
499 :
500 5 : CHIP_ERROR NewVidVerificationSignerX509Cert(const X509CertRequestParams & requestParams,
501 : const Crypto::P256PublicKey & subjectPubkey, const Crypto::P256Keypair & issuerKeypair,
502 : MutableByteSpan & x509Cert)
503 : {
504 : CertType certType;
505 :
506 5 : ReturnErrorOnFailure(requestParams.SubjectDN.GetCertType(certType));
507 4 : VerifyOrReturnError(certType == CertType::kVidVerificationSigner, CHIP_ERROR_INVALID_ARGUMENT);
508 :
509 3 : ReturnErrorOnFailure(requestParams.IssuerDN.GetCertType(certType));
510 3 : VerifyOrReturnError((certType == CertType::kICA) || (certType == CertType::kRoot), CHIP_ERROR_INVALID_ARGUMENT);
511 :
512 3 : return NewChipX509Cert(requestParams, subjectPubkey, issuerKeypair, x509Cert);
513 : }
514 :
515 46 : DLL_EXPORT CHIP_ERROR NewNodeOperationalX509Cert(const X509CertRequestParams & requestParams,
516 : const Crypto::P256PublicKey & subjectPubkey,
517 : const Crypto::P256Keypair & issuerKeypair, MutableByteSpan & x509Cert)
518 : {
519 : CertType certType;
520 :
521 46 : ReturnErrorOnFailure(requestParams.SubjectDN.GetCertType(certType));
522 45 : VerifyOrReturnError(certType == CertType::kNode, CHIP_ERROR_INVALID_ARGUMENT);
523 :
524 44 : ReturnErrorOnFailure(requestParams.IssuerDN.GetCertType(certType));
525 44 : VerifyOrReturnError(certType == CertType::kICA || certType == CertType::kRoot, CHIP_ERROR_INVALID_ARGUMENT);
526 :
527 43 : return NewChipX509Cert(requestParams, subjectPubkey, issuerKeypair, x509Cert);
528 : }
529 :
530 : } // namespace Credentials
531 : } // namespace chip
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