/* * Copyright (c) 2023 Project CHIP Authors * All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @file * mbedTLS based implementation of CHIP crypto primitives related to certificate * generation and validation. */ #include "CHIPCryptoPAL.h" #include "CHIPCryptoPALmbedTLS.h" #include #include #include #include #include #include #include #if defined(MBEDTLS_X509_CRT_PARSE_C) #include #endif // defined(MBEDTLS_X509_CRT_PARSE_C) namespace chip { namespace Crypto { CHIP_ERROR VerifyCertificateSigningRequest(const uint8_t * csr_buf, size_t csr_length, P256PublicKey & pubkey) { #if defined(MBEDTLS_X509_CSR_PARSE_C) ReturnErrorOnFailure(VerifyCertificateSigningRequestFormat(csr_buf, csr_length)); // TODO: For some embedded targets, mbedTLS library doesn't have mbedtls_x509_csr_parse_der, and mbedtls_x509_csr_parse_free. // Taking a step back, embedded targets likely will not process CSR requests. Adding this action item to reevaluate // this if there's a need for this processing for embedded targets. CHIP_ERROR error = CHIP_NO_ERROR; size_t pubkey_size = 0; mbedtls_ecp_keypair * keypair = nullptr; P256ECDSASignature signature; MutableByteSpan out_raw_sig_span(signature.Bytes(), signature.Capacity()); mbedtls_x509_csr csr; mbedtls_x509_csr_init(&csr); int result = mbedtls_x509_csr_parse_der(&csr, csr_buf, csr_length); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); // Verify the signature algorithm and public key type VerifyOrExit(csr.CHIP_CRYPTO_PAL_PRIVATE(sig_md) == MBEDTLS_MD_SHA256, error = CHIP_ERROR_UNSUPPORTED_SIGNATURE_TYPE); VerifyOrExit(csr.CHIP_CRYPTO_PAL_PRIVATE(sig_pk) == MBEDTLS_PK_ECDSA, error = CHIP_ERROR_WRONG_KEY_TYPE); keypair = mbedtls_pk_ec(csr.CHIP_CRYPTO_PAL_PRIVATE_X509(pk)); // Copy the public key from the CSR result = mbedtls_ecp_point_write_binary(&keypair->CHIP_CRYPTO_PAL_PRIVATE(grp), &keypair->CHIP_CRYPTO_PAL_PRIVATE(Q), MBEDTLS_ECP_PF_UNCOMPRESSED, &pubkey_size, Uint8::to_uchar(pubkey), pubkey.Length()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); VerifyOrExit(pubkey_size == pubkey.Length(), error = CHIP_ERROR_INTERNAL); // Convert DER signature to raw signature error = EcdsaAsn1SignatureToRaw(kP256_FE_Length, ByteSpan{ csr.CHIP_CRYPTO_PAL_PRIVATE(sig).CHIP_CRYPTO_PAL_PRIVATE_X509(p), csr.CHIP_CRYPTO_PAL_PRIVATE(sig).CHIP_CRYPTO_PAL_PRIVATE_X509(len) }, out_raw_sig_span); VerifyOrExit(error == CHIP_NO_ERROR, error = CHIP_ERROR_INVALID_ARGUMENT); VerifyOrExit(out_raw_sig_span.size() == (kP256_FE_Length * 2), error = CHIP_ERROR_INTERNAL); signature.SetLength(out_raw_sig_span.size()); // Verify the signature using the public key error = pubkey.ECDSA_validate_msg_signature(csr.CHIP_CRYPTO_PAL_PRIVATE_X509(cri).CHIP_CRYPTO_PAL_PRIVATE_X509(p), csr.CHIP_CRYPTO_PAL_PRIVATE_X509(cri).CHIP_CRYPTO_PAL_PRIVATE_X509(len), signature); SuccessOrExit(error); exit: mbedtls_x509_csr_free(&csr); _log_mbedTLS_error(result); return error; #else ChipLogError(Crypto, "MBEDTLS_X509_CSR_PARSE_C is not enabled. CSR cannot be parsed"); return CHIP_ERROR_UNSUPPORTED_CHIP_FEATURE; #endif } namespace { #if defined(MBEDTLS_X509_CRT_PARSE_C) bool IsTimeGreaterThanEqual(const mbedtls_x509_time * const timeA, const mbedtls_x509_time * const timeB) { // checks if two values are different and if yes, then returns first > second. #define RETURN_STRICTLY_GREATER_IF_DIFFERENT(component) \ { \ auto valueA = timeA->CHIP_CRYPTO_PAL_PRIVATE_X509(component); \ auto valueB = timeB->CHIP_CRYPTO_PAL_PRIVATE_X509(component); \ \ if (valueA != valueB) \ { \ return valueA > valueB; \ } \ } RETURN_STRICTLY_GREATER_IF_DIFFERENT(year); RETURN_STRICTLY_GREATER_IF_DIFFERENT(mon); RETURN_STRICTLY_GREATER_IF_DIFFERENT(day); RETURN_STRICTLY_GREATER_IF_DIFFERENT(hour); RETURN_STRICTLY_GREATER_IF_DIFFERENT(min); RETURN_STRICTLY_GREATER_IF_DIFFERENT(sec); // all above are equal return true; } CHIP_ERROR IsCertificateValidAtIssuance(const mbedtls_x509_crt * candidateCertificate, const mbedtls_x509_crt * issuerCertificate) { mbedtls_x509_time candidateNotBeforeTime = candidateCertificate->CHIP_CRYPTO_PAL_PRIVATE_X509(valid_from); mbedtls_x509_time issuerNotBeforeTime = issuerCertificate->CHIP_CRYPTO_PAL_PRIVATE_X509(valid_from); mbedtls_x509_time issuerNotAfterTime = issuerCertificate->CHIP_CRYPTO_PAL_PRIVATE_X509(valid_to); // check if candidateCertificate is issued at or after issuerCertificate's notBefore timestamp VerifyOrReturnError(IsTimeGreaterThanEqual(&candidateNotBeforeTime, &issuerNotBeforeTime), CHIP_ERROR_CERT_EXPIRED); // check if candidateCertificate is issued at or before issuerCertificate's notAfter timestamp VerifyOrReturnError(IsTimeGreaterThanEqual(&issuerNotAfterTime, &candidateNotBeforeTime), CHIP_ERROR_CERT_EXPIRED); return CHIP_NO_ERROR; } int CallbackForCustomValidityCheck(void * data, mbedtls_x509_crt * crt, int depth, uint32_t * flags) { mbedtls_x509_crt * leafCert = reinterpret_cast(data); mbedtls_x509_crt * issuerCert = crt; // Ignore any time validy error performed by the standard mbedTLS code. *flags &= ~(static_cast(MBEDTLS_X509_BADCERT_EXPIRED | MBEDTLS_X509_BADCERT_FUTURE)); // Verify that the leaf certificate has a notBefore time valid within the validity period of the issuerCertificate. // Note that this callback is invoked for each certificate in the chain. if (IsCertificateValidAtIssuance(leafCert, issuerCert) != CHIP_NO_ERROR) { return MBEDTLS_ERR_X509_INVALID_DATE; } return 0; } constexpr uint8_t sOID_AttributeType_CommonName[] = { 0x55, 0x04, 0x03 }; constexpr uint8_t sOID_AttributeType_MatterVendorId[] = { 0x2B, 0x06, 0x01, 0x04, 0x01, 0x82, 0xA2, 0x7C, 0x02, 0x01 }; constexpr uint8_t sOID_AttributeType_MatterProductId[] = { 0x2B, 0x06, 0x01, 0x04, 0x01, 0x82, 0xA2, 0x7C, 0x02, 0x02 }; constexpr uint8_t sOID_SigAlgo_ECDSAWithSHA256[] = { 0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x04, 0x03, 0x02 }; constexpr uint8_t sOID_Extension_BasicConstraints[] = { 0x55, 0x1D, 0x13 }; constexpr uint8_t sOID_Extension_KeyUsage[] = { 0x55, 0x1D, 0x0F }; constexpr uint8_t sOID_Extension_SubjectKeyIdentifier[] = { 0x55, 0x1D, 0x0E }; constexpr uint8_t sOID_Extension_AuthorityKeyIdentifier[] = { 0x55, 0x1D, 0x23 }; constexpr uint8_t sOID_Extension_CRLDistributionPoint[] = { 0x55, 0x1D, 0x1F }; /** * Compares an mbedtls_asn1_buf structure (oidBuf) to a reference OID represented as uint8_t array (oid). */ #define OID_CMP(oid, oidBuf) \ ((MBEDTLS_ASN1_OID == (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(tag)) && \ (sizeof(oid) == (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(len)) && \ (memcmp((oid), (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(p), (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(len)) == 0)) #endif // defined(MBEDTLS_X509_CRT_PARSE_C) } // anonymous namespace CHIP_ERROR VerifyAttestationCertificateFormat(const ByteSpan & cert, AttestationCertType certType) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; int result = 0; mbedtls_x509_crt mbed_cert; unsigned char * p = nullptr; const unsigned char * end = nullptr; size_t len = 0; bool extBasicPresent = false; bool extKeyUsagePresent = false; VerifyOrReturnError(!cert.empty(), CHIP_ERROR_INVALID_ARGUMENT); mbedtls_x509_crt_init(&mbed_cert); result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(cert.data()), cert.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); // "version" value is 1 higher than the actual encoded value. VerifyOrExit(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(version) - 1 == 2, error = CHIP_ERROR_INTERNAL); // Verify signature algorithms is ECDSA with SHA256. VerifyOrExit(OID_CMP(sOID_SigAlgo_ECDSAWithSHA256, mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(sig_oid)), error = CHIP_ERROR_INTERNAL); // Verify public key presence and format. { Crypto::P256PublicKey pubkey; SuccessOrExit(error = ExtractPubkeyFromX509Cert(cert, pubkey)); } p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p); end = p + mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(len); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); while (p < end) { mbedtls_x509_buf extOID = { 0, 0, nullptr }; int extCritical = 0; result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); /* Get extension ID */ result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OID); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); extOID.CHIP_CRYPTO_PAL_PRIVATE_X509(tag) = MBEDTLS_ASN1_OID; extOID.CHIP_CRYPTO_PAL_PRIVATE_X509(len) = len; extOID.CHIP_CRYPTO_PAL_PRIVATE_X509(p) = p; p += len; /* Get optional critical */ result = mbedtls_asn1_get_bool(&p, end, &extCritical); VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_INTERNAL); /* Data should be octet string type */ result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); if (OID_CMP(sOID_Extension_BasicConstraints, extOID)) { int isCA = 0; int pathLen = -1; VerifyOrExit(extCritical, error = CHIP_ERROR_INTERNAL); extBasicPresent = true; result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); if (len > 0) { unsigned char * seqStart = p; result = mbedtls_asn1_get_bool(&p, end, &isCA); VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_INTERNAL); // Check if pathLen is there by validating if the cursor didn't get to the end of // of the internal SEQUENCE for the basic constraints encapsulation. // Missing pathLen optional tag will leave pathLen == -1 for following checks. bool hasPathLen = (p != (seqStart + len)); if (hasPathLen) { // Extract pathLen value, making sure it's a valid format. result = mbedtls_asn1_get_int(&p, end, &pathLen); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); } } if (certType == AttestationCertType::kDAC) { VerifyOrExit(!isCA && pathLen == -1, error = CHIP_ERROR_INTERNAL); } else if (certType == AttestationCertType::kPAI) { VerifyOrExit(isCA && pathLen == 0, error = CHIP_ERROR_INTERNAL); } else { // For PAA, pathlen must be absent or equal to 1 (see Matter 1.1 spec 6.2.2.5) VerifyOrExit(isCA && (pathLen == -1 || pathLen == 1), error = CHIP_ERROR_INTERNAL); } } else if (OID_CMP(sOID_Extension_KeyUsage, extOID)) { mbedtls_x509_bitstring bs = { 0, 0, nullptr }; unsigned int keyUsage = 0; VerifyOrExit(extCritical, error = CHIP_ERROR_INTERNAL); extKeyUsagePresent = true; result = mbedtls_asn1_get_bitstring(&p, p + len, &bs); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); for (size_t i = 0; i < bs.CHIP_CRYPTO_PAL_PRIVATE_X509(len) && i < sizeof(unsigned int); i++) { keyUsage |= static_cast(bs.CHIP_CRYPTO_PAL_PRIVATE_X509(p)[i]) << (8 * i); } if (certType == AttestationCertType::kDAC) { // SHALL only have the digitalSignature bit set. VerifyOrExit(keyUsage == MBEDTLS_X509_KU_DIGITAL_SIGNATURE, error = CHIP_ERROR_INTERNAL); } else { bool keyCertSignFlag = keyUsage & MBEDTLS_X509_KU_KEY_CERT_SIGN; bool crlSignFlag = keyUsage & MBEDTLS_X509_KU_CRL_SIGN; bool otherFlags = keyUsage & ~static_cast(MBEDTLS_X509_KU_CRL_SIGN | MBEDTLS_X509_KU_KEY_CERT_SIGN | MBEDTLS_X509_KU_DIGITAL_SIGNATURE); VerifyOrExit(keyCertSignFlag && crlSignFlag && !otherFlags, error = CHIP_ERROR_INTERNAL); } } else { p += len; } } // Verify basic and key usage extensions are present. VerifyOrExit(extBasicPresent && extKeyUsagePresent, error = CHIP_ERROR_INTERNAL); // Verify that SKID and AKID extensions are present. { uint8_t kidBuf[kSubjectKeyIdentifierLength]; MutableByteSpan kid(kidBuf); SuccessOrExit(error = ExtractSKIDFromX509Cert(cert, kid)); if (certType == AttestationCertType::kDAC || certType == AttestationCertType::kPAI) { // Mandatory extension for DAC and PAI certs. SuccessOrExit(error = ExtractAKIDFromX509Cert(cert, kid)); } } exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) cert; (void) certType; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR ValidateCertificateChain(const uint8_t * rootCertificate, size_t rootCertificateLen, const uint8_t * caCertificate, size_t caCertificateLen, const uint8_t * leafCertificate, size_t leafCertificateLen, CertificateChainValidationResult & result) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; mbedtls_x509_crt certChain; mbedtls_x509_crt rootCert; int mbedResult; uint32_t flags = 0; result = CertificateChainValidationResult::kInternalFrameworkError; VerifyOrReturnError(rootCertificate != nullptr && rootCertificateLen != 0, (result = CertificateChainValidationResult::kRootArgumentInvalid, CHIP_ERROR_INVALID_ARGUMENT)); VerifyOrReturnError(leafCertificate != nullptr && leafCertificateLen != 0, (result = CertificateChainValidationResult::kLeafArgumentInvalid, CHIP_ERROR_INVALID_ARGUMENT)); mbedtls_x509_crt_init(&certChain); mbedtls_x509_crt_init(&rootCert); /* Start of chain */ mbedResult = mbedtls_x509_crt_parse(&certChain, Uint8::to_const_uchar(leafCertificate), leafCertificateLen); VerifyOrExit(mbedResult == 0, (result = CertificateChainValidationResult::kLeafFormatInvalid, error = CHIP_ERROR_INTERNAL)); /* Add the intermediate to the chain, if present */ if (caCertificate != nullptr && caCertificateLen > 0) { mbedResult = mbedtls_x509_crt_parse(&certChain, Uint8::to_const_uchar(caCertificate), caCertificateLen); VerifyOrExit(mbedResult == 0, (result = CertificateChainValidationResult::kICAFormatInvalid, error = CHIP_ERROR_INTERNAL)); } /* Parse the root cert */ mbedResult = mbedtls_x509_crt_parse(&rootCert, Uint8::to_const_uchar(rootCertificate), rootCertificateLen); VerifyOrExit(mbedResult == 0, (result = CertificateChainValidationResult::kRootFormatInvalid, error = CHIP_ERROR_INTERNAL)); /* Verify the chain against the root */ mbedResult = mbedtls_x509_crt_verify(&certChain, &rootCert, nullptr, nullptr, &flags, CallbackForCustomValidityCheck, &certChain); switch (mbedResult) { case 0: VerifyOrExit(flags == 0, (result = CertificateChainValidationResult::kInternalFrameworkError, error = CHIP_ERROR_INTERNAL)); result = CertificateChainValidationResult::kSuccess; break; case MBEDTLS_ERR_X509_INVALID_DATE: case MBEDTLS_ERR_X509_CERT_VERIFY_FAILED: result = CertificateChainValidationResult::kChainInvalid; error = CHIP_ERROR_CERT_NOT_TRUSTED; break; default: result = CertificateChainValidationResult::kInternalFrameworkError; error = CHIP_ERROR_INTERNAL; break; } exit: _log_mbedTLS_error(mbedResult); mbedtls_x509_crt_free(&certChain); mbedtls_x509_crt_free(&rootCert); #else (void) rootCertificate; (void) rootCertificateLen; (void) caCertificate; (void) caCertificateLen; (void) leafCertificate; (void) leafCertificateLen; (void) result; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR IsCertificateValidAtIssuance(const ByteSpan & candidateCertificate, const ByteSpan & issuerCertificate) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; mbedtls_x509_crt mbedCandidateCertificate; mbedtls_x509_crt mbedIssuerCertificate; int result; VerifyOrReturnError(!candidateCertificate.empty() && !issuerCertificate.empty(), CHIP_ERROR_INVALID_ARGUMENT); mbedtls_x509_crt_init(&mbedCandidateCertificate); mbedtls_x509_crt_init(&mbedIssuerCertificate); result = mbedtls_x509_crt_parse(&mbedCandidateCertificate, Uint8::to_const_uchar(candidateCertificate.data()), candidateCertificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); result = mbedtls_x509_crt_parse(&mbedIssuerCertificate, Uint8::to_const_uchar(issuerCertificate.data()), issuerCertificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); // Verify that the candidateCertificate has a notBefore time valid within the validity period of the issuerCertificate. SuccessOrExit(error = IsCertificateValidAtIssuance(&mbedCandidateCertificate, &mbedIssuerCertificate)); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbedCandidateCertificate); mbedtls_x509_crt_free(&mbedIssuerCertificate); #else (void) candidateCertificate; (void) issuerCertificate; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR IsCertificateValidAtCurrentTime(const ByteSpan & certificate) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; mbedtls_x509_crt mbedCertificate; int result; VerifyOrReturnError(!certificate.empty(), CHIP_ERROR_INVALID_ARGUMENT); mbedtls_x509_crt_init(&mbedCertificate); result = mbedtls_x509_crt_parse(&mbedCertificate, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); // check if certificate's notBefore timestamp is earlier than or equal to current time. result = mbedtls_x509_time_is_past(&mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(valid_from)); VerifyOrExit(result == 1, error = CHIP_ERROR_CERT_EXPIRED); // check if certificate's notAfter timestamp is later than current time. result = mbedtls_x509_time_is_future(&mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(valid_to)); VerifyOrExit(result == 1, error = CHIP_ERROR_CERT_EXPIRED); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbedCertificate); #else (void) certificate; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR ExtractPubkeyFromX509Cert(const ByteSpan & certificate, Crypto::P256PublicKey & pubkey) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; mbedtls_x509_crt mbed_cert; mbedtls_ecp_keypair * keypair = nullptr; size_t pubkey_size = 0; mbedtls_x509_crt_init(&mbed_cert); int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); VerifyOrExit(mbedtls_pk_get_type(&(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(pk))) == MBEDTLS_PK_ECKEY, error = CHIP_ERROR_INVALID_ARGUMENT); keypair = mbedtls_pk_ec(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(pk)); VerifyOrExit(keypair->CHIP_CRYPTO_PAL_PRIVATE(grp).id == MapECPGroupId(pubkey.Type()), error = CHIP_ERROR_INVALID_ARGUMENT); // Copy the public key from the cert in raw point format result = mbedtls_ecp_point_write_binary(&keypair->CHIP_CRYPTO_PAL_PRIVATE(grp), &keypair->CHIP_CRYPTO_PAL_PRIVATE(Q), MBEDTLS_ECP_PF_UNCOMPRESSED, &pubkey_size, Uint8::to_uchar(pubkey.Bytes()), pubkey.Length()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); VerifyOrExit(pubkey_size == pubkey.Length(), error = CHIP_ERROR_INTERNAL); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) certificate; (void) pubkey; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } namespace { CHIP_ERROR ExtractKIDFromX509Cert(bool extractSKID, const ByteSpan & certificate, MutableByteSpan & kid) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_ERROR_NOT_FOUND; mbedtls_x509_crt mbed_cert; unsigned char * p = nullptr; const unsigned char * end = nullptr; size_t len = 0; mbedtls_x509_crt_init(&mbed_cert); int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); // TODO: The mbedTLS team is working on supporting SKID and AKID extensions processing. // Once it is supported, this code should be updated. p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p); end = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p) + mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(len); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); while (p < end) { result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OID); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); mbedtls_x509_buf extOID = { MBEDTLS_ASN1_OID, len, p }; bool extractCurrentExtSKID = extractSKID && OID_CMP(sOID_Extension_SubjectKeyIdentifier, extOID); bool extractCurrentExtAKID = !extractSKID && OID_CMP(sOID_Extension_AuthorityKeyIdentifier, extOID); p += len; int is_critical = 0; result = mbedtls_asn1_get_bool(&p, end, &is_critical); VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); if (extractCurrentExtSKID || extractCurrentExtAKID) { if (extractCurrentExtSKID) { result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); } else { result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); // Other optional fields, authorityCertIssuer and authorityCertSerialNumber, // will be skipped if present. } VerifyOrExit(len == kSubjectKeyIdentifierLength, error = CHIP_ERROR_WRONG_CERT_TYPE); VerifyOrExit(len <= kid.size(), error = CHIP_ERROR_BUFFER_TOO_SMALL); memcpy(kid.data(), p, len); if (kid.size() > len) { kid.reduce_size(len); } ExitNow(error = CHIP_NO_ERROR); break; } p += len; } exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) certificate; (void) kid; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } } // namespace CHIP_ERROR ExtractSKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & skid) { return ExtractKIDFromX509Cert(true, certificate, skid); } CHIP_ERROR ExtractAKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & akid) { return ExtractKIDFromX509Cert(false, certificate, akid); } CHIP_ERROR ExtractCRLDistributionPointURIFromX509Cert(const ByteSpan & certificate, MutableCharSpan & cdpurl) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_ERROR_NOT_FOUND; mbedtls_x509_crt mbed_cert; unsigned char * p = nullptr; const unsigned char * end = nullptr; size_t len = 0; size_t cdpExtCount = 0; VerifyOrReturnError(!certificate.empty() && CanCastTo(certificate.size()), CHIP_ERROR_INVALID_ARGUMENT); mbedtls_x509_crt_init(&mbed_cert); int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p); end = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p) + mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(len); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); while (p < end) { result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OID); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); mbedtls_x509_buf extOID = { MBEDTLS_ASN1_OID, len, p }; bool isCurrentExtCDP = OID_CMP(sOID_Extension_CRLDistributionPoint, extOID); p += len; int is_critical = 0; result = mbedtls_asn1_get_bool(&p, end, &is_critical); VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); unsigned char * end_of_ext = p + len; if (isCurrentExtCDP) { // Only one CRL Distribution Point Extension is allowed. cdpExtCount++; VerifyOrExit(cdpExtCount <= 1, error = CHIP_ERROR_NOT_FOUND); // CRL Distribution Point Extension is encoded as a sequence of DistributionPoint: // CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint // // This implementation only supports a single DistributionPoint (sequence of size 1), // which is verified by comparing (p + len == end_of_ext) result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); VerifyOrExit(p + len == end_of_ext, error = CHIP_ERROR_NOT_FOUND); // The DistributionPoint is a sequence of three optional elements: // DistributionPoint ::= SEQUENCE { // distributionPoint [0] DistributionPointName OPTIONAL, // reasons [1] ReasonFlags OPTIONAL, // cRLIssuer [2] GeneralNames OPTIONAL } result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); VerifyOrExit(p + len == end_of_ext, error = CHIP_ERROR_NOT_FOUND); // The DistributionPointName is: // DistributionPointName ::= CHOICE { // fullName [0] GeneralNames, // nameRelativeToCRLIssuer [1] RelativeDistinguishedName } // // The URI should be encoded in the fullName element. result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); // GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); unsigned char * end_of_general_names = p + len; // The CDP URI is encoded as a uniformResourceIdentifier field of the GeneralName: // GeneralName ::= CHOICE { // otherName [0] OtherName, // rfc822Name [1] IA5String, // dNSName [2] IA5String, // x400Address [3] ORAddress, // directoryName [4] Name, // ediPartyName [5] EDIPartyName, // uniformResourceIdentifier [6] IA5String, // iPAddress [7] OCTET STRING, // registeredID [8] OBJECT IDENTIFIER } result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); // Only single URI instance in the GeneralNames is supported VerifyOrExit(p + len == end_of_general_names, error = CHIP_ERROR_NOT_FOUND); const char * urlptr = reinterpret_cast(p); VerifyOrExit((len > strlen(kValidCDPURIHttpPrefix) && strncmp(urlptr, kValidCDPURIHttpPrefix, strlen(kValidCDPURIHttpPrefix)) == 0) || (len > strlen(kValidCDPURIHttpsPrefix) && strncmp(urlptr, kValidCDPURIHttpsPrefix, strlen(kValidCDPURIHttpsPrefix)) == 0), error = CHIP_ERROR_NOT_FOUND); error = CopyCharSpanToMutableCharSpan(CharSpan(urlptr, len), cdpurl); SuccessOrExit(error); } p = end_of_ext; } VerifyOrExit(cdpExtCount == 1, error = CHIP_ERROR_NOT_FOUND); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) certificate; (void) cdpurl; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR ExtractCDPExtensionCRLIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & crlIssuer) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_ERROR_NOT_FOUND; mbedtls_x509_crt mbed_cert; unsigned char * p = nullptr; const unsigned char * end = nullptr; size_t len = 0; size_t cdpExtCount = 0; VerifyOrReturnError(!certificate.empty() && CanCastTo(certificate.size()), CHIP_ERROR_INVALID_ARGUMENT); mbedtls_x509_crt_init(&mbed_cert); int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p); end = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p) + mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(len); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); while (p < end) { result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OID); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); mbedtls_x509_buf extOID = { MBEDTLS_ASN1_OID, len, p }; bool isCurrentExtCDP = OID_CMP(sOID_Extension_CRLDistributionPoint, extOID); p += len; int is_critical = 0; result = mbedtls_asn1_get_bool(&p, end, &is_critical); VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_WRONG_CERT_TYPE); result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); unsigned char * end_of_ext = p + len; if (isCurrentExtCDP) { // Only one CRL Distribution Point Extension is allowed. cdpExtCount++; VerifyOrExit(cdpExtCount <= 1, error = CHIP_ERROR_NOT_FOUND); // CRL Distribution Point Extension is encoded as a sequence of DistributionPoint: // CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint // // This implementation only supports a single DistributionPoint (sequence of size 1), // which is verified by comparing (p + len == end_of_ext) result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); VerifyOrExit(p + len == end_of_ext, error = CHIP_ERROR_NOT_FOUND); // The DistributionPoint is a sequence of three optional elements: // DistributionPoint ::= SEQUENCE { // distributionPoint [0] DistributionPointName OPTIONAL, // reasons [1] ReasonFlags OPTIONAL, // cRLIssuer [2] GeneralNames OPTIONAL } result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); VerifyOrExit(p + len == end_of_ext, error = CHIP_ERROR_NOT_FOUND); // If distributionPoint element presents, ignore it result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0); if (result == 0) { p += len; VerifyOrExit(p < end_of_ext, error = CHIP_ERROR_NOT_FOUND); } // Check if cRLIssuer element present result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 2); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); // The CRL Issuer is encoded as a directoryName field of the GeneralName: // GeneralName ::= CHOICE { // otherName [0] OtherName, // rfc822Name [1] IA5String, // dNSName [2] IA5String, // x400Address [3] ORAddress, // directoryName [4] Name, // ediPartyName [5] EDIPartyName, // uniformResourceIdentifier [6] IA5String, // iPAddress [7] OCTET STRING, // registeredID [8] OBJECT IDENTIFIER } result = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_X509_SAN_DIRECTORY_NAME); VerifyOrExit(result == 0, error = CHIP_ERROR_NOT_FOUND); VerifyOrExit(p + len == end_of_ext, error = CHIP_ERROR_NOT_FOUND); error = CopySpanToMutableSpan(ByteSpan(p, len), crlIssuer); SuccessOrExit(error); } p = end_of_ext; } VerifyOrExit(cdpExtCount == 1, error = CHIP_ERROR_NOT_FOUND); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) certificate; (void) crlIssuer; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR ExtractSerialNumberFromX509Cert(const ByteSpan & certificate, MutableByteSpan & serialNumber) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; int result = 0; uint8_t * p = nullptr; size_t len = 0; mbedtls_x509_crt mbed_cert; mbedtls_x509_crt_init(&mbed_cert); result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(serial).CHIP_CRYPTO_PAL_PRIVATE_X509(p); len = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(serial).CHIP_CRYPTO_PAL_PRIVATE_X509(len); VerifyOrExit(len <= serialNumber.size(), error = CHIP_ERROR_BUFFER_TOO_SMALL); memcpy(serialNumber.data(), p, len); serialNumber.reduce_size(len); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) certificate; (void) serialNumber; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } CHIP_ERROR ExtractVIDPIDFromX509Cert(const ByteSpan & certificate, AttestationCertVidPid & vidpid) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; mbedtls_x509_crt mbed_cert; mbedtls_asn1_named_data * dnIterator = nullptr; AttestationCertVidPid vidpidFromCN; mbedtls_x509_crt_init(&mbed_cert); int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); for (dnIterator = &mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(subject); dnIterator != nullptr; dnIterator = dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(next)) { DNAttrType attrType = DNAttrType::kUnspecified; if (OID_CMP(sOID_AttributeType_CommonName, dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(oid))) { attrType = DNAttrType::kCommonName; } else if (OID_CMP(sOID_AttributeType_MatterVendorId, dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(oid))) { attrType = DNAttrType::kMatterVID; } else if (OID_CMP(sOID_AttributeType_MatterProductId, dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(oid))) { attrType = DNAttrType::kMatterPID; } size_t val_len = dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(val).CHIP_CRYPTO_PAL_PRIVATE_X509(len); uint8_t * val_p = dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(val).CHIP_CRYPTO_PAL_PRIVATE_X509(p); error = ExtractVIDPIDFromAttributeString(attrType, ByteSpan(val_p, val_len), vidpid, vidpidFromCN); SuccessOrExit(error); } // If Matter Attributes were not found use values extracted from the CN Attribute, // which might be uninitialized as well. if (!vidpid.Initialized()) { vidpid = vidpidFromCN; } exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbed_cert); #else (void) certificate; (void) vidpid; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } namespace { CHIP_ERROR ExtractRawDNFromX509Cert(bool extractSubject, const ByteSpan & certificate, MutableByteSpan & dn) { #if defined(MBEDTLS_X509_CRT_PARSE_C) CHIP_ERROR error = CHIP_NO_ERROR; int result = 0; uint8_t * p = nullptr; size_t len = 0; mbedtls_x509_crt mbedCertificate; VerifyOrReturnError(!certificate.empty(), CHIP_ERROR_INVALID_ARGUMENT); mbedtls_x509_crt_init(&mbedCertificate); result = mbedtls_x509_crt_parse(&mbedCertificate, Uint8::to_const_uchar(certificate.data()), certificate.size()); VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); if (extractSubject) { len = mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(subject_raw).CHIP_CRYPTO_PAL_PRIVATE_X509(len); p = mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(subject_raw).CHIP_CRYPTO_PAL_PRIVATE_X509(p); } else { len = mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(issuer_raw).CHIP_CRYPTO_PAL_PRIVATE_X509(len); p = mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(issuer_raw).CHIP_CRYPTO_PAL_PRIVATE_X509(p); } VerifyOrExit(len <= dn.size(), error = CHIP_ERROR_BUFFER_TOO_SMALL); memcpy(dn.data(), p, len); dn.reduce_size(len); exit: _log_mbedTLS_error(result); mbedtls_x509_crt_free(&mbedCertificate); #else (void) certificate; (void) dn; CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) return error; } } // namespace CHIP_ERROR ExtractSubjectFromX509Cert(const ByteSpan & certificate, MutableByteSpan & subject) { return ExtractRawDNFromX509Cert(true, certificate, subject); } CHIP_ERROR ExtractIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & issuer) { return ExtractRawDNFromX509Cert(false, certificate, issuer); } CHIP_ERROR ReplaceCertIfResignedCertFound(const ByteSpan & referenceCertificate, const ByteSpan * candidateCertificates, size_t candidateCertificatesCount, ByteSpan & outCertificate) { #if defined(MBEDTLS_X509_CRT_PARSE_C) uint8_t referenceSubjectBuf[kMaxCertificateDistinguishedNameLength]; uint8_t referenceSKIDBuf[kSubjectKeyIdentifierLength]; MutableByteSpan referenceSubject(referenceSubjectBuf); MutableByteSpan referenceSKID(referenceSKIDBuf); outCertificate = referenceCertificate; VerifyOrReturnError(candidateCertificates != nullptr && candidateCertificatesCount != 0, CHIP_NO_ERROR); ReturnErrorOnFailure(ExtractSubjectFromX509Cert(referenceCertificate, referenceSubject)); ReturnErrorOnFailure(ExtractSKIDFromX509Cert(referenceCertificate, referenceSKID)); for (size_t i = 0; i < candidateCertificatesCount; i++) { const ByteSpan candidateCertificate = candidateCertificates[i]; uint8_t candidateSubjectBuf[kMaxCertificateDistinguishedNameLength]; uint8_t candidateSKIDBuf[kSubjectKeyIdentifierLength]; MutableByteSpan candidateSubject(candidateSubjectBuf); MutableByteSpan candidateSKID(candidateSKIDBuf); ReturnErrorOnFailure(ExtractSubjectFromX509Cert(candidateCertificate, candidateSubject)); ReturnErrorOnFailure(ExtractSKIDFromX509Cert(candidateCertificate, candidateSKID)); if (referenceSKID.data_equal(candidateSKID) && referenceSubject.data_equal(candidateSubject)) { outCertificate = candidateCertificate; return CHIP_NO_ERROR; } } return CHIP_NO_ERROR; #else (void) referenceCertificate; (void) candidateCertificates; (void) candidateCertificatesCount; (void) outCertificate; return CHIP_ERROR_NOT_IMPLEMENTED; #endif // defined(MBEDTLS_X509_CRT_PARSE_C) } } // namespace Crypto } // namespace chip