# 03. RC (Resource Certifications) ## 3.1 对象定位 RC是资源证书，包括CA和EE ## 3.2 原始载体与编码 - 载体：X.509 certificates. - 编码：DER（遵循 RFC 5280 的 Certificate 结构与字段语义，但受 RPKI profile 限制）RFC 6487 §4 ### 3.2.1 基本语法（RFC 5280 §4，RFC 6487 ） RC是遵循RFC5280定义的X.509Certificate语法(RFC 5280 §4)，并且符合RFC 6487 §4的约束。只选取RFC 6487 §4章节列出来的字段。（Unless specifically noted as being OPTIONAL, all the fields listed here MUST be present, and any other fields MUST NOT appear in a conforming resource certificate.） ``` Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signatureValue BIT STRING } TBSCertificate ::= SEQUENCE { version [0] EXPLICIT Version MUST be v3, serialNumber CertificateSerialNumber, signature AlgorithmIdentifier, issuer Name, subject Name, validity Validity, subjectPublicKeyInfo SubjectPublicKeyInfo, extensions [3] EXPLICIT Extensions OPTIONAL -- If present, version MUST be v3 } Version ::= INTEGER { v1(0), v2(1), v3(2) } CertificateSerialNumber ::= INTEGER Validity ::= SEQUENCE { notBefore Time, notAfter Time } Time ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime } UniqueIdentifier ::= BIT STRING SubjectPublicKeyInfo ::= SEQUENCE { algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING } Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension Extension ::= SEQUENCE { extnID OBJECT IDENTIFIER, critical BOOLEAN DEFAULT FALSE, extnValue OCTET STRING -- contains the DER encoding of an ASN.1 value -- corresponding to the extension type identified -- by extnID } ``` > 其中`Name` "a valid X.501 distinguished name"(RFC 6487 §4.4) ### 3.2.2 证书扩展字段 （RFC 6487 §4.8) RC的证书扩展字段按照RFC 6487 §4.8的规定，有以下几个扩展： - Basic Constraints - Subject Key Identifier - Authority Key Identifier - Key Usage - Extended Key Usage(CA证书，以及验证RPKI对象的EE证书不能出现该字段。非RPKI对象的EE可以出现EKU，但必须为non-critical) - CRL Distribution Points - Authority Information Access - Subject Information Access - SIA for CA Certificates - SIA for EE Certificates - Certificate Policies - IP Resources - AS Resources ``` # Basic Constraints id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 } BasicConstraints ::= SEQUENCE { cA BOOLEAN DEFAULT FALSE } # Subject Key Identifier id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 14 } SubjectKeyIdentifier ::= KeyIdentifier KeyIdentifier ::= OCTET STRING # Authority Key Identifier id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 } AuthorityKeyIdentifier ::= SEQUENCE { keyIdentifier [0] KeyIdentifier OPTIONAL } # Key Usage id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 } KeyUsage ::= BIT STRING { digitalSignature (0), nonRepudiation (1), -- recent editions of X.509 have -- renamed this bit to contentCommitment keyEncipherment (2), dataEncipherment (3), keyAgreement (4), keyCertSign (5), cRLSign (6), encipherOnly (7), decipherOnly (8) } # Extended Key Usage id-ce-extKeyUsage OBJECT IDENTIFIER ::= { id-ce 37 } ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId KeyPurposeId ::= OBJECT IDENTIFIER # CRL Distribution Points id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= { id-ce 31 } CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL } DistributionPointName ::= CHOICE { fullName [0] GeneralNames } ## Authority Information Access id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 } AuthorityInfoAccessSyntax ::= SEQUENCE SIZE (1..MAX) OF AccessDescription AccessDescription ::= SEQUENCE { accessMethod OBJECT IDENTIFIER, accessLocation GeneralName } # AccessDescription id-ad OBJECT IDENTIFIER ::= { id-pkix 48 } # CA 证书发布位置 id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 } # OCSP 服务地址 id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 } # Subject Information Access id-pe-subjectInfoAccess OBJECT IDENTIFIER ::= { id-pe 11 } SubjectInfoAccessSyntax ::= SEQUENCE SIZE (1..MAX) OF AccessDescription AccessDescription ::= SEQUENCE { accessMethod OBJECT IDENTIFIER, accessLocation GeneralName } ## Subject Information Access for CA (RFC 6487 §4.8.8.1) id-ad OBJECT IDENTIFIER ::= { id-pkix 48 } id-ad-rpkiManifest OBJECT IDENTIFIER ::= { id-ad 10 } 必须存在一个accessMethod=id-ad-caRepository，accessLocation=rsyncURI。 必须存在一个accessMethod=id-ad-repiManifest, accessLocation=rsync URI，指向该CA的mft对象。 ## Subject Information Access for EE (RFC 6487 §4.8.8.2) id-ad-signedObject OBJECT IDENTIFIER ::= { id-ad 11 } 必须存在一个accessMethod=id-ad-signedObject, accessLocation=rsyncURI 不允许其他的accessMethod # Certificate Policies id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 } anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 } certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyInformation ::= SEQUENCE { policyIdentifier CertPolicyId, policyQualifiers SEQUENCE SIZE (1..MAX) OF PolicyQualifierInfo OPTIONAL } CertPolicyId ::= OBJECT IDENTIFIER PolicyQualifierInfo ::= SEQUENCE { policyQualifierId PolicyQualifierId, qualifier ANY DEFINED BY policyQualifierId } -- policyQualifierIds for Internet policy qualifiers id-qt OBJECT IDENTIFIER ::= { id-pkix 2 } id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 } id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 } PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice ) Qualifier ::= CHOICE { cPSuri CPSuri, userNotice UserNotice } CPSuri ::= IA5String UserNotice ::= SEQUENCE { noticeRef NoticeReference OPTIONAL, explicitText DisplayText OPTIONAL } NoticeReference ::= SEQUENCE { organization DisplayText, noticeNumbers SEQUENCE OF INTEGER } DisplayText ::= CHOICE { ia5String IA5String (SIZE (1..200)), visibleString VisibleString (SIZE (1..200)), bmpString BMPString (SIZE (1..200)), utf8String UTF8String (SIZE (1..200)) } # IP Resources id-pe-ipAddrBlocks OBJECT IDENTIFIER ::= { id-pe 7 } IPAddrBlocks ::= SEQUENCE OF IPAddressFamily IPAddressFamily ::= SEQUENCE { -- AFI & optional SAFI -- addressFamily OCTET STRING (SIZE (2..3)), ipAddressChoice IPAddressChoice } IPAddressChoice ::= CHOICE { inherit NULL, -- inherit from issuer -- addressesOrRanges SEQUENCE OF IPAddressOrRange } IPAddressOrRange ::= CHOICE { addressPrefix IPAddress, addressRange IPAddressRange } IPAddressRange ::= SEQUENCE { min IPAddress, max IPAddress } IPAddress ::= BIT STRING # AS Resources id-pe-autonomousSysIds OBJECT IDENTIFIER ::= { id-pe 8 } ASIdentifiers ::= SEQUENCE { asnum [0] EXPLICIT ASIdentifierChoice OPTIONAL, rdi [1] EXPLICIT ASIdentifierChoice OPTIONAL} ASIdentifierChoice ::= CHOICE { inherit NULL, -- inherit from issuer -- asIdsOrRanges SEQUENCE OF ASIdOrRange } ASIdOrRange ::= CHOICE { id ASId, range ASRange } ASRange ::= SEQUENCE { min ASId, max ASId } ASId ::= INTEGER ``` # 3.3 抽象数据结构 采用X509 Certificate + Resource + 约束校验的方式组合 | 字段 | 类型 | 语义 | 约束/解析规则 | RFC 引用 | |----------|---------------------|----------|---------|---------------| | cert_der | Vec | 证书原始数据 | | | | cert | X509Certificate | 基础X509证书 | | RFC 5280 §4.1 | | resource | ResourceSet | 资源集合 | | | # 3.4 约束规则 ## 3.4.1 Cert约束校验规则 RFC 6487中规定的证书的字段参见[3.2.1 ](#321-基本语法rfc-5280-4rfc-6487-) - | 字段 | 语义 | 约束/解析规则 | RFC 引用 | |-----------|-------|----------------------------------------------|--------------| | version | 证书版本 | 必须是v3(值为2） | RFC6487 §4.1 | | serial | 证书编号 | 同一个CA签发的证书编号必须唯一 | RFC6487 §4.2 | | validity | 证书有效期 | notBefore：时间不能早于证书的生成时间。若时间段大于上级证书的有效期，也是有效的 | RFC6487 §4.6 | ## 3.4.2 Cert Extentions中字段的约束校验规则 RFC 6487中规定的扩展字段参见[3.2.2 ](#322-证书扩展字段-rfc-6487-48) | 字段 | critical | 语义 | 约束/解析规则 | RFC 引用 | |----------------------------|----------|-------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------| | basicConstraints | Y | 证书类型 | CA证书：cA=TRUE; EE证书：cA=FALSE | RFC6487 §4.8.1 | | subjectKeyIdentifier | N | 证书公钥 | SKI = SHA-1(DER-encoded SPKI bit string) | RFC6487 §4.8.2 | | authorityKeyIdentifier | N | 父证书的公钥 | 字段只包含keyIdentifier，不能包含authorityCertIssuer和authorityCertSerialNumber；除了自签名CA外，其余证书必须出现。自签名CA若出现该字段，则等于SKI | RFC6487 §4.8.3 | | keyUsage | Y | 证书公钥的用途权限 | CA证书：keyCertSign = TRUE, cRLSign = TRUE 其他都是FALSE。EE证书：digitalSignature = TRUE 其他都是FALSE | RFC6487 §4.8.4 | | extendedKeyUsage | N | 扩展证书公钥的用途权限 | CA证书：不能出现EKU；验证 RPKI 对象的 EE 证书：不能出现EKU；非 RPKI 对象的 EE：可以出现EKU，但必须为non-critical. | RFC6487 §4.8.5 | | cRLDistributionPoints | N | CRL的发布点位置 | 字段：distributionPoint，不能包含reasons、cRLIssuer。其中distributionPoint字段包含：fullName，不能包含nameRelativeToCRLIssuer。fullName的格式必须是URI。自签名证书禁止出现该字段。非自签名证书必须出现。一个CA只能有一个CRL。一个CRLDP只能包含一个distributionPoint。但一个distributionPoint字段中可以包含多于1个的URI，但必须包含rsync URI且必须是最新的。 | RFC6487 §4.8.6 | | authorityInformationAccess | N | 签发者的发布点位置 | 除了自签名的CA，必须出现。自签名CA，禁止出现。推荐的URI访问方式是rsync，并且rsyncURI的话，必须指定accessMethod=id-ad-caIssuers | RFC6487 §4.8.7 | | subjectInformationAccess | N | 发布点位置 | CA证书：必须存在。必须存在一个accessMethod=id-ad-caRepository，accessLocation=rsyncURI。必须存在一个accessMethod=id-ad-repiManifest,accessLocation=rsync URI，指向该CA的mft对象。 EE证书：必须存在。必须存在一个accessMethod=id-ad-signedObject,accessLocation=rsyncURI。不允许其他的accessMethod | RFC6487 §4.8.8 | | certificatePolicies | Y | 证书策略 | 必须存在，并且只能存在一种策略：RFC 6484 — RPKI Certificate Policy (CP) | RFC6487 §4.8.9 | | iPResources | Y | IP地址集合 | 所有的RPKI证书中必须包含IP Resources或者ASResources，或者两者都包含。 | RFC6487 §4.8.10 | | aSResources | Y | ASN集合 | 所有的RPKI证书中必须包含IP Resources或者ASResources，或者两者都包含。 | RFC6487 §4.8.11 |