X.509

This document defines a new GeneralName.otherName for inclusion in the X.509 Subject Alternative Name (SAN) and Issuer Alternative Name (IAN) extensions to carry an IEEE Media Access Control (MAC) address. The new name form makes it possible to bind a Layer 2 interface identifier to a public key certificate. Additionally, this document defines how constraints on this name form can be encoded and processed in the X.509 Name Constraints extension (NCE).

RFC 7589 defines how to protect Network Configuration Protocol (NETCONF) messages with TLS 1.2. This document updates RFC 7589 to update support requirements for TLS 1.2 and add TLS 1.3 support requirements, including restrictions on the use of TLS 1.3's early data.

The Resource Public Key Infrastructure (RPKI) makes use of signed objects called "manifests", each of which includes a "manifest number". This document updates RFC 9286 by specifying issuer and Relying Party (RP) behaviour when a manifest number reaches the largest possible value, a situation not considered in RFC 9286.

The Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM) is a quantum-resistant Key Encapsulation Mechanism. This document specifies the conventions for using the ML-KEM in X.509 Public Key Infrastructure. The conventions for the subject public keys and private keys are also specified.

This document defines a placeholder X.509 signature algorithm that may be used in contexts where the consumer of the certificate is not expected to verify the signature. As part of this, it updates RFC 5280.

Digital signatures are used within the X.509 Public Key Infrastructure, such as X.509 certificates and Certificate Revocation Lists (CRLs), as well as to sign messages. This document specifies the conventions for using the Stateless Hash-Based Digital Signature Algorithm (SLH-DSA) in the X.509 Public Key Infrastructure. The conventions for the associated signatures, subject public keys, and private keys are also specified.

Digital signatures are used within X.509 certificates and Certificate Revocation Lists (CRLs), and to sign messages. This document specifies the conventions for using FIPS 204, the Module-Lattice-Based Digital Signature Algorithm (ML-DSA) in Internet X.509 certificates and CRLs. The conventions for the associated signatures, subject public keys, and private key are also described.

This document describes the Internet X.509 Public Key Infrastructure (PKI) Certificate Management Protocol (CMP). Protocol messages are defined for X.509v3 certificate creation and management. CMP provides interactions between client systems and PKI components such as a Registration Authority (RA) and a Certification Authority (CA).

This document adds support for management of certificates containing a Key Encapsulation Mechanism (KEM) public key and uses EnvelopedData instead of EncryptedValue. This document also includes the updates specified in Section 2 and Appendix A.2 of RFC 9480.

This document obsoletes RFC 4210, and together with RFC 9811, it also obsoletes RFC 9480. Appendix F of this document updates Section 9 of RFC 5912.

This document describes how to layer the Certificate Management Protocol (CMP) over HTTP.

It includes the updates to RFC 6712 specified in Section 3 of RFC 9480; these updates introduce CMP URIs using a well-known prefix. It obsoletes RFC 6712; and, together with RFC 9810, it also obsoletes RFC 9480.

This document revises how the Resource Public Key Infrastructure (RPKI) handles Certificate Revocation List (CRL) Number extensions. This document updates RFC 6487.

RFC 5280 defines the Extended Key Usage (EKU) extension and specifies several extended key purpose identifiers (KeyPurposeIds) for use with that extension in X.509 certificates. This document defines KeyPurposeIds for general-purpose and trust anchor configuration files, for software and firmware update packages, and for safety-critical communication to be included in the EKU extension of X.509 v3 public key certificates.

This document specifies algorithm identifiers and ASN.1 encoding formats for the following stateful Hash-Based Signature (HBS) schemes: Hierarchical Signature System (HSS), eXtended Merkle Signature Scheme (XMSS), and XMSS^MT (a multi-tree variant of XMSS). This specification applies to the Internet X.509 Public Key Infrastructure (PKI) when digital signatures are used to sign certificates and certificate revocation lists (CRLs).

This document defines a new Certificate Signing Request (CSR) attribute, relatedCertRequest, and a new X.509 certificate extension, RelatedCertificate. The use of the relatedCertRequest attribute in a CSR and the inclusion of the RelatedCertificate extension in the resulting certificate together provide additional assurance that two certificates each belong to the same end entity. This mechanism is particularly useful in the context of non-composite hybrid authentication, which enables users to employ the same certificates in hybrid authentication as in authentication done with only traditional or post-quantum algorithms.

RFC 5280 specifies several extended key purpose identifiers (KeyPurposeIds) for X.509 certificates. This document defines an Instant Messaging (IM) identity KeyPurposeId for inclusion in the Extended Key Usage (EKU) extension of X.509 v3 public key certificates

A Trust Anchor Locator (TAL) is used by Relying Parties (RPs) in the Resource Public Key Infrastructure (RPKI) to locate and validate a Trust Anchor (TA) Certification Authority (CA) certificate used in RPKI validation. This document defines an RPKI signed object for a Trust Anchor Key (TAK). A TAK object can be used by a TA to signal to RPs the location(s) of the accompanying CA certificate for the current public key, as well as the successor public key and the location(s) of its CA certificate. This object helps to support planned key rollovers without impacting RPKI validation.

This document updates RFC 5280 to replace the algorithm for X.509 policy validation with an equivalent, more efficient algorithm. The original algorithm built a structure that scaled exponentially in the worst case, leaving implementations vulnerable to denial-of-service attacks.

X.509v3 public key certificates are profiled in RFC 5280. Short-lived certificates are seeing greater use in the Internet. The Certification Authority (CA) that issues these short-lived certificates do not publish revocation information because the certificate lifespan that is shorter than the time needed to detect, report, and distribute revocation information. Some long-lived X.509v3 public key certificates never expire, and they are never revoked. This specification defines the noRevAvail certificate extension so that a relying party can readily determine that the CA does not publish revocation information for the certificate, and it updates the certification path validation algorithm defined in RFC 5280 so that revocation checking is skipped when the noRevAvail certificate extension is present.

This document defines a new name form for inclusion in the otherName field of an X.509 Subject Alternative Name and Issuer Alternative Name extension that allows a certificate subject to be associated with an internationalized email address.

This document updates RFC 5280 and obsoletes RFC 8398.

RFC 5280 specifies several extended key purpose identifiers (KeyPurposeIds) for X.509 certificates. This document defines encrypting JSON objects in HTTP messages, using JSON Web Tokens (JWTs), and signing the OAuth 2.0 access tokens KeyPurposeIds for inclusion in the Extended Key Usage (EKU) extension of X.509 v3 public key certificates used by Network Functions (NFs) for the 5G System.

This document specifies a certificate extension for including logotypes in public key certificates and attribute certificates. This document obsoletes RFCs 3709 and 6170.

The CBOR Object Signing and Encryption (COSE) message structure uses references to keys in general. For some algorithms, additional properties are defined that carry parameters relating to keys as needed. The COSE Key structure is used for transporting keys outside of COSE messages. This document extends the way that keys can be identified and transported by providing attributes that refer to or contain X.509 certificates.

This document specifies the certificate extension for including Network Function Types (NFTypes) for the 5G System in X.509 v3 public key certificates as profiled in RFC 5280.

RFC 5280 specifies several extended key purpose identifiers (KeyPurposeIds) for X.509 certificates. This document defines a general-purpose Document-Signing KeyPurposeId for inclusion in the Extended Key Usage (EKU) extension of X.509 public key certificates. Document-Signing applications may require that the EKU extension be present and that a Document-Signing KeyPurposeId be indicated in order for the certificate to be acceptable to that Document-Signing application.

This document defines a Cryptographic Message Syntax (CMS) protected content type for use with the Resource Public Key Infrastructure (RPKI) to carry a general-purpose listing of checksums (a 'checklist'). The objective is to allow for the creation of an attestation, termed an "RPKI Signed Checklist (RSC)", which contains one or more checksums of arbitrary digital objects (files) that are signed with a specific set of Internet Number Resources. When validated, an RSC confirms that the respective Internet resource holder produced the RSC.

This document describes a mechanism that, through the use of opportunistic Transport Layer Security (TLS), enables encryption of Remote Procedure Call (RPC) transactions while they are in transit. The proposed mechanism interoperates with Open Network Computing (ONC) RPC implementations that do not support it. This document updates RFC 5531.

This document updates RFC 8410 to clarify existing semantics, and specify missing semantics, for key usage bits when used in certificates that support the Ed25519, Ed448, X25519, and X448 Elliptic Curve Cryptography algorithms.

This document specifies protocol interfaces profiled by the United States National Security Agency (NSA) for National Security System (NSS) servers that provide public key certificates, Certificate Revocation Lists (CRLs), and symmetric keys to NSS clients. Servers that support these interfaces are referred to as Secure Object Delivery Protocol (SODP) servers. The intended audience for this profile comprises developers of client devices that will obtain key management services from NSA-operated SODP servers. Interfaces supported by SODP servers include Enrollment over Secure Transport (EST) and its extensions as well as Certificate Management over CMS (CMC).

This profile applies to the capabilities, configuration, and operation of all components of US National Security Systems (SP 800-59). It is also appropriate for other US Government systems that process high-value information. It is made publicly available for use by developers and operators of these and any other system deployments.

The S/MIME development community benefits from sharing samples of signed or encrypted data. This document facilitates such collaboration by defining a small set of X.509v3 certificates and keys for use when generating such samples.

This document describes encoding formats, identifiers, and parameter formats for the GOST R 34.10-2012 and GOST R 34.11-2012 algorithms for use in the Internet X.509 Public Key Infrastructure (PKI).

This specification is developed to facilitate implementations that wish to support the GOST algorithms. This document does not imply IETF endorsement of the cryptographic algorithms used in this document.

The Extensible Authentication Protocol (EAP), defined in RFC 3748, provides a standard mechanism for support of multiple authentication methods. EAP-TLS and other TLS-based EAP methods are widely deployed and used for network access authentication. Large certificates and long certificate chains combined with authenticators that drop an EAP session after only 40 - 50 round trips is a major deployment problem. This document looks at this problem in detail and describes the potential solutions available.

This document describes version 2.0 of the Certificate Transparency (CT) protocol for publicly logging the existence of Transport Layer Security (TLS) server certificates as they are issued or observed, in a manner that allows anyone to audit certification authority (CA) activity and notice the issuance of suspect certificates as well as to audit the certificate logs themselves. The intent is that eventually clients would refuse to honor certificates that do not appear in a log, effectively forcing CAs to add all issued certificates to the logs.

This document obsoletes RFC 6962. It also specifies a new TLS extension that is used to send various CT log artifacts.

Logs are network services that implement the protocol operations for submissions and queries that are defined in this document.

RFC 7299 describes the object identifiers that were assigned by the Public Key Infrastructure using X.509 (PKIX) Working Group in an arc that was allocated by IANA (1.3.6.1.5.5.7). A small number of object identifiers that were assigned in RFC 4212 are omitted from RFC 7299, and this document updates RFC 7299 to correct that oversight.

RFC 8226 specifies the use of certificates for Secure Telephone Identity Credentials; these certificates are often called "Secure Telephone Identity Revisited (STIR) Certificates". RFC 8226 provides a certificate extension to constrain the JSON Web Token (JWT) claims that can be included in the Personal Assertion Token (PASSporT), as defined in RFC 8225. If the PASSporT signer includes a JWT claim outside the constraint boundaries, then the PASSporT recipient will reject the entire PASSporT. This document updates RFC 8226; it provides all of the capabilities available in the original certificate extension as well as an additional way to constrain the allowable JWT claims. The enhanced extension can also provide a list of claims that are not allowed to be included in the PASSporT.

This document updates the cryptographic algorithm requirements for the Password-Based Message Authentication Code in the Internet X.509 Public Key Infrastructure Certificate Request Message Format (CRMF) specified in RFC 4211.

This document updates RFC 5480 to specify semantics for the keyEncipherment and dataEncipherment key usage bits when used in certificates that support Elliptic Curve Cryptography.

This document describes OAuth client authentication and certificate-bound access and refresh tokens using mutual Transport Layer Security (TLS) authentication with X.509 certificates. OAuth clients are provided a mechanism for authentication to the authorization server using mutual TLS, based on either self-signed certificates or public key infrastructure (PKI). OAuth authorization servers are provided a mechanism for binding access tokens to a client's mutual-TLS certificate, and OAuth protected resources are provided a method for ensuring that such an access token presented to it was issued to the client presenting the token.

Digital signatures are used to sign messages, X.509 certificates, and Certificate Revocation Lists (CRLs). This document updates the "Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile" (RFC 3279) and describes the conventions for using the SHAKE function family in Internet X.509 certificates and revocation lists as one-way hash functions with the RSA Probabilistic signature and Elliptic Curve Digital Signature Algorithm (ECDSA) signature algorithms. The conventions for the associated subject public keys are also described.

Public Key Infrastructure using X.509 (PKIX) certificates are used for a number of purposes, the most significant of which is the authentication of domain names. Thus, certification authorities (CAs) in the Web PKI are trusted to verify that an applicant for a certificate legitimately represents the domain name(s) in the certificate. As of this writing, this verification is done through a collection of ad hoc mechanisms. This document describes a protocol that a CA and an applicant can use to automate the process of verification and certificate issuance. The protocol also provides facilities for other certificate management functions, such as certificate revocation.

This document specifies algorithm identifiers and ASN.1 encoding formats for elliptic curve constructs using the curve25519 and curve448 curves. The signature algorithms covered are Ed25519 and Ed448. The key agreement algorithms covered are X25519 and X448. The encoding for public key, private key, and Edwards-curve Digital Signature Algorithm (EdDSA) structures is provided.

This document reclassifies the RFCs related to the United States National Security Agency (NSA) Suite B cryptographic algorithms as Historic, and it discusses the reasons for doing so. This document moves seven Informational RFCs to Historic status: RFCs 5759, 6239, 6318, 6379, 6380, 6403, and 6460. In addition, it moves three obsolete Informational RFCs to Historic status: RFCs 4869, 5008, and 5430.

Experience has shown that it is difficult to deploy proper PKIX certificates for Transport Layer Security (TLS) in multi-tenanted environments. As a result, domains hosted in such environments often deploy applications using certificates that identify the hosting service, not the hosted domain. Such deployments force end users and peer services to accept a certificate with an improper identifier, resulting in degraded security. This document defines methods that make it easier to deploy certificates for proper server identity checking in non-HTTP application protocols. Although these methods were developed for use in the Extensible Messaging and Presence Protocol (XMPP) as a Domain Name Association (DNA) prooftype, they might also be usable in other non-HTTP application protocols.

The purpose of the TLS feature extension is to prevent downgrade attacks that are not otherwise prevented by the TLS protocol. In particular, the TLS feature extension may be used to mandate support for revocation checking features in the TLS protocol such as Online Certificate Status Protocol (OCSP) stapling. Informing clients that an OCSP status response will always be stapled permits an immediate failure in the case that the response is not stapled. This in turn prevents a denial-of-service attack that might otherwise be possible.

The Network Configuration Protocol (NETCONF) provides mechanisms to install, manipulate, and delete the configuration of network devices. This document describes how to use the Transport Layer Security (TLS) protocol with mutual X.509 authentication to secure the exchange of NETCONF messages. This revision of RFC 5539 documents the new message framing used by NETCONF 1.1 and it obsoletes RFC 5539.

This document describes and discusses the textual encodings of the Public-Key Infrastructure X.509 (PKIX), Public-Key Cryptography Standards (PKCS), and Cryptographic Message Syntax (CMS). The textual encodings are well-known, are implemented by several applications and libraries, and are widely deployed. This document articulates the de facto rules by which existing implementations operate and defines them so that future implementations can interoperate.

The Internet Key Exchange Version 2 (IKEv2) protocol has limited support for the Elliptic Curve Digital Signature Algorithm (ECDSA). The current version only includes support for three Elliptic Curve groups, and there is a fixed hash algorithm tied to each group. This document generalizes IKEv2 signature support to allow any signature method supported by PKIX and also adds signature hash algorithm negotiation. This is a generic mechanism and is not limited to ECDSA; it can also be used with other signature algorithms.

When the Public-Key Infrastructure using X.509 (PKIX) Working Group was chartered, an object identifier arc was allocated by IANA for use by that working group. This document describes the object identifiers that were assigned in that arc, returns control of that arc to IANA, and establishes IANA allocation policies for any future assignments within that arc.

This document provides several certificate policy identifiers for testing certificate handling software.

This document specifies additional example methods for generating Key Identifier values for use in the AKI (Authority Key Identifier) and SKI (Subject Key Identifier) certificate extensions.

This document profiles certificate enrollment for clients using Certificate Management over CMS (CMC) messages over a secure transport. This profile, called Enrollment over Secure Transport (EST), describes a simple, yet functional, certificate management protocol targeting Public Key Infrastructure (PKI) clients that need to acquire client certificates and associated Certification Authority (CA) certificates. It also supports client-generated public/private key pairs as well as key pairs generated by the CA.

This document specifies a protocol useful in determining the current status of a digital certificate without requiring Certificate Revocation Lists (CRLs). Additional mechanisms addressing PKIX operational requirements are specified in separate documents. This document obsoletes RFCs 2560 and 6277. It also updates RFC 5912.

This document updates RFC 5280, the "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile". This document changes the set of acceptable encoding methods for the explicitText field of the user notice policy qualifier and clarifies the rules for converting internationalized domain name labels to ASCII. This document also provides some clarifications on the use of self-signed certificates, trust anchors, and some updated security considerations. [STANDARDS-TRACK]

This document describes a protocol, called kx509, for using Kerberos tickets to acquire X.509 certificates. These certificates may be used for many of the same purposes as X.509 certificates acquired by other means, but if a Kerberos infrastructure already exists, then the overhead of using kx509 may be much less.

While not standardized, this protocol is already in use at several large organizations, and certificates issued with this protocol are recognized by the International Grid Trust Federation. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines a set of Secure/Multipurpose Internet Mail Extensions (S/MIME) Capability types for ASN.1 encoding for the current set of public keys defined by the PKIX working group. This facilitates the ability for a requester to specify information on the public keys and signature algorithms to be used in responses. "Online Certificate Status Protocol Algorithm Agility" (RFC 6277) details an example of where this is used. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes the certificate policy for a Public Key Infrastructure (PKI) used to support attestations about Internet Number Resource (INR) holdings. Each organization that distributes IP addresses or Autonomous System (AS) numbers to an organization will, in parallel, issue a (public key) certificate reflecting this distribution. These certificates will enable verification that the resources indicated in the certificate have been distributed to the holder of the associated private key and that this organization is the current, unique holder of these resources. This memo documents an Internet Best Current Practice.

This document defines a standard profile for X.509 certificates for the purpose of supporting validation of assertions of "right-of-use" of Internet Number Resources (INRs). The certificates issued under this profile are used to convey the issuer's authorization of the subject to be regarded as the current holder of a "right-of-use" of the INRs that are described in the certificate. This document contains the normative specification of Certificate and Certificate Revocation List (CRL) syntax in the Resource Public Key Infrastructure (RPKI). This document also specifies profiles for the format of certificate requests and specifies the Relying Party RPKI certificate path validation procedure. [STANDARDS-TRACK]

SEcure Neighbor Discovery (SEND) defines the Name Type field in the ICMPv6 Trust Anchor option. This document specifies new Name Type fields based on certificate Subject Key Identifiers (SKIs). [STANDARDS-TRACK]

The United States government has published guidelines for "NSA Suite\0B Cryptography", which defines cryptographic algorithm policy for national security applications. This document specifies a profile of the Certificate Management over CMS (CMC) protocol for managing Suite B X.509 public key certificates. This profile is a refinement of RFCs 5272, 5273, and 5274. This document is not an Internet Standards Track specification; it is published for informational purposes.

Many current applications use the certificate-based authentication features in Transport Layer Security (TLS) to allow clients to verify that a connected server properly represents a desired domain name. Typically, this authentication has been based on PKIX certificate chains rooted in well-known certificate authorities (CAs), but additional information can be provided via the DNS itself. This document describes a set of use cases in which the DNS and DNS Security Extensions (DNSSEC) could be used to make assertions that support the TLS authentication process. The main focus of this document is TLS server authentication, but it also covers TLS client authentication for applications where TLS clients are identified by domain names. [STANDARDS-TRACK]

The Cryptographic Message Syntax (CMS) format, and many associated formats, are expressed using ASN.1. The current ASN.1 modules conform to the 1988 version of ASN.1. This document updates some auxiliary ASN.1 modules to conform to the 2008 version of ASN.1; the 1988 ASN.1 modules remain the normative version. There are no bits- on-the-wire changes to any of the formats; this is simply a change to the syntax. This document is not an Internet Standards Track specification; it is published for informational purposes.

Abstract Syntax Notation One (ASN.1) is widely used throughout the IETF Security Area and has been for many years. Some specifications were written using a now deprecated version of ASN.1 and some were written using the current version of ASN.1. Not all ASN.1 compilers support both older and current syntax. This document is intended to provide guidance to specification authors and to implementers converting ASN.1 modules from one version of ASN.1 to another version without causing changes to the "bits on the wire". This document does not provide a comprehensive tutorial of any version of ASN.1. Instead, it addresses ASN.1 features that are used in IETF Security Area specifications with a focus on items that vary with the ASN.1 version. This document is not an Internet Standards Track specification; it is published for informational purposes.

A trust anchor represents an authoritative entity via a public key and associated data. The public key is used to verify digital signatures, and the associated data is used to constrain the types of information for which the trust anchor is authoritative. A relying party uses trust anchors to determine if a digitally signed object is valid by verifying a digital signature using the trust anchor's public key, and by enforcing the constraints expressed in the associated data for the trust anchor. This document describes some of the problems associated with the lack of a standard trust anchor management mechanism and defines requirements for data formats and push-based protocols designed to address these problems. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes a transport independent protocol for the management of trust anchors (TAs) and community identifiers stored in a trust anchor store. The protocol makes use of the Cryptographic Message Syntax (CMS), and a digital signature is used to provide integrity protection and data origin authentication. The protocol can be used to manage trust anchor stores containing trust anchors represented as Certificate, TBSCertificate, or TrustAnchorInfo objects. [STANDARDS-TRACK]

This document describes how to use information associated with a trust anchor public key when validating certification paths. This information can be used to constrain the usage of a trust anchor. Typically, constraints are used to limit the certificate policies and names that can appear in certification paths validated using a trust anchor. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes how to construct and interpret certain information in a PKIX-compliant (Public Key Infrastructure using X.509) certificate for use in a Session Initiation Protocol (SIP) over Transport Layer Security (TLS) connection. More specifically, this document describes how to encode and extract the identity of a SIP domain in a certificate and how to use that identity for SIP domain authentication. As such, this document is relevant both to implementors of SIP and to issuers of certificates. [STANDARDS-TRACK]

This memo documents an extended key usage (EKU) X.509 certificate extension for restricting the applicability of a certificate to use with a Session Initiation Protocol (SIP) service. As such, in addition to providing rules for SIP implementations, this memo also provides guidance to issuers of certificates for use with SIP. This document defines an Experimental Protocol for the Internet community.

The Cryptographic Message Syntax (CMS) format, and many associated formats, are expressed using ASN.1. The current ASN.1 modules conform to the 1988 version of ASN.1. This document updates those ASN.1 modules to conform to the 2002 version of ASN.1. There are no bits-on-the-wire changes to any of the formats; this is simply a change to the syntax. This document is not an Internet Standards Track specification; it is published for informational purposes.

The Public Key Infrastructure using X.509 (PKIX) certificate format, and many associated formats, are expressed using ASN.1. The current ASN.1 modules conform to the 1988 version of ASN.1. This document updates those ASN.1 modules to conform to the 2002 version of ASN.1. There are no bits-on-the-wire changes to any of the formats; this is simply a change to the syntax. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines the syntax and semantics for the Clearance attribute and the Authority Clearance Constraints extension in X.509 certificates. The Clearance attribute is used to indicate the clearance held by the subject. The Clearance attribute may appear in the subject directory attributes extension of a public key certificate or in the attributes field of an attribute certificate. The Authority Clearance Constraints certificate extension values in a Trust Anchor (TA), in Certification Authority (CA) public key certificates, and in an Attribute Authority (AA) public key certificate in a certification path for a given subject constrain the effective Clearance of the subject. [STANDARDS-TRACK]

This document describes a structure for representing trust anchor information. A trust anchor is an authoritative entity represented by a public key and associated data. The public key is used to verify digital signatures, and the associated data is used to constrain the types of information or actions for which the trust anchor is authoritative. The structures defined in this document are intended to satisfy the format-related requirements defined in Trust Anchor Management Requirements. [STANDARDS-TRACK]

This document defines the Device Owner attribute. It indicates the entity (e.g., company, organization, department, agency) that owns the device. This attribute may be included in public key certificates and attribute certificates. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines the clearance sponsor attribute. It indicates the entity that sponsored (i.e., granted) the clearance. This attribute is intended for use in public key certificates and attribute certificates that also include the clearance attribute. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document specifies a MIME media type used to carry a single attribute certificate as defined in RFC 5755. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document updates RFC 3161. It allows the use of ESSCertIDv2, as defined in RFC 5035, to specify the hash of a signer certificate when the hash is calculated with a function other than the Secure Hash Algorithm (SHA-1). [STANDARDS-TRACK]

This specification defines a profile for the use of X.509 Attribute Certificates in Internet Protocols. Attribute certificates may be used in a wide range of applications and environments covering a broad spectrum of interoperability goals and a broader spectrum of operational and assurance requirements. The goal of this document is to establish a common baseline for generic applications requiring broad interoperability as well as limited special purpose requirements. The profile places emphasis on attribute certificate support for Internet electronic mail, IPsec, and WWW security applications. This document obsoletes RFC 3281. [STANDARDS-TRACK]

This document updates RFC 4055. It updates the conventions for using the RSA Encryption Scheme - Optimal Asymmetric Encryption Padding (RSAES-OAEP) key transport algorithm in the Internet X.509 Public Key Infrastructure (PKI). Specifically, it updates the conventions for algorithm parameters in an X.509 certificate's subjectPublicKeyInfo field. [STANDARDS-TRACK]

This memo describes X.509 key identifiers and signature encoding for version 2 of the KeyNote trust-management system (RFC 2704). X.509 certificates (RFC 5280) can be directly used in the Authorizer or Licensees field (or in both fields) in a KeyNote assertion, allowing for easy integration with protocols that already use X.509 certificates for authentication.

In addition, the document defines additional signature types that use other hash functions (beyond the MD5 and SHA1 hash functions that are defined in RFC 2792). This document is not an Internet Standards Track specification; it is published for informational purposes.

This document updates RFC 3279 to specify algorithm identifiers and ASN.1 encoding rules for the Digital Signature Algorithm (DSA) and Elliptic Curve Digital Signature Algorithm (ECDSA) digital signatures when using SHA-224, SHA-256, SHA-384, or SHA-512 as the hashing algorithm. This specification applies to the Internet X.509 Public Key infrastructure (PKI) when digital signatures are used to sign certificates and certificate revocation lists (CRLs). This document also identifies all four SHA2 hash algorithms for use in the Internet X.509 PKI. [STANDARDS-TRACK]

This document specifies a base profile for X.509 v3 Certificates and X.509 v2 Certificate Revocation Lists (CRLs) for use with the United States National Security Agency's Suite B Cryptography. The reader is assumed to have familiarity with RFC 5280, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile". This document is not an Internet Standards Track specification; it is published for informational purposes.

Some applications that associate state information with public key certificates can benefit from a way to link together a set of certificates that belong to the same end entity and that can safely be considered equivalent to one another for the purposes of referencing that application-state information. This memo defines a certificate extension that allows applications to establish the required linkage without introducing a new application protocol data unit. This memo defines an Experimental Protocol for the Internet community.

This document defines a practical architecture and protocols for offering privacy for a user who requests and uses an X.509 certificate containing a pseudonym, while still retaining the ability to map such a certificate to the real user who requested it. The architecture is compatible with IETF certificate request formats such as PKCS10 (RFC 2986) and CMC (RFC 5272). The architecture separates the authorities involved in issuing a certificate: one for verifying ownership of a private key (Blind Issuer) and the other for validating the contents of a certificate (Anonymity Issuer). The end entity (EE) certificates issued under this model are called Traceable Anonymous Certificates (TACs). This memo defines an Experimental Protocol for the Internet community.

This document specifies the syntax and semantics for the Subject Public Key Information field in certificates that support Elliptic Curve Cryptography. This document updates Sections 2.3.5 and 5, and the ASN.1 module of "Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 3279. [STANDARDS-TRACK]

This memo profiles the X.509 v3 certificate and X.509 v2 certificate revocation list (CRL) for use in the Internet. An overview of this approach and model is provided as an introduction. The X.509 v3 certificate format is described in detail, with additional information regarding the format and semantics of Internet name forms. Standard certificate extensions are described and two Internet-specific extensions are defined. A set of required certificate extensions is specified. The X.509 v2 CRL format is described in detail along with standard and Internet-specific extensions. An algorithm for X.509 certification path validation is described. An ASN.1 module and examples are provided in the appendices. [STANDARDS-TRACK]

This document describes eight Diffie-Hellman groups that can be used in conjunction with IETF protocols to provide security for Internet communications. The groups allow implementers to use the same groups with a variety of security protocols, e.g., SMIME, Secure SHell (SSH), Transport Layer Security (TLS), and Internet Key Exchange (IKE).

All of these groups comply in form and structure with relevant standards from ISO, ANSI, NIST, and the IEEE. These groups are compatible with all IETF standards that make use of Diffie-Hellman or Elliptic Curve Diffie-Hellman cryptography.

These groups and the associated test data are defined by NIST on their web site [EX80056A], but have not yet (as of this writing) been published in a formal NIST document. Publication of these groups and associated test data, as well as describing how to use Diffie-Hellman and Elliptic Curve Diffie-Hellman for key agreement in all of the protocols cited below, in one RFC, will facilitate development of interoperable implementations and support the Federal Information Processing Standard (FIPS) validation of implementations that make use of these groups. This memo provides information for the Internet community.

The Server-Based Certificate Validation Protocol (SCVP) allows a client to delegate certification path construction and certification path validation to a server. The path construction or validation (e.g., making sure that none of the certificates in the path are revoked) is performed according to a validation policy, which contains one or more trust anchors. It allows simplification of client implementations and use of a set of predefined validation policies. [STANDARDS-TRACK]

This document defines a new name form for inclusion in the otherName field of an X.509 Subject Alternative Name extension that allows a certificate subject to be associated with the service name and domain name components of a DNS Service Resource Record. [STANDARDS-TRACK]

The Internet Key Exchange (IKE) and Public Key Infrastructure for X.509 (PKIX) certificate profile both provide frameworks that must be profiled for use in a given application. This document provides a profile of IKE and PKIX that defines the requirements for using PKI technology in the context of IKE/IPsec. The document complements protocol specifications such as IKEv1 and IKEv2, which assume the existence of public key certificates and related keying materials, but which do not address PKI issues explicitly. This document addresses those issues. The intended audience is implementers of PKI for IPsec. [STANDARDS-TRACK]

This document describes how the IKEv1 (Internet Key Exchange version 1), IKEv2, and IPsec protocols use hash functions, and explains the level of vulnerability of these protocols to the reduced collision resistance of the MD5 and SHA-1 hash algorithms. This memo provides information for the Internet community.

This document defines the Subject Identification Method (SIM) for including a privacy-sensitive identifier in the subjectAltName extension of a certificate.

The SIM is an optional feature that may be used by relying parties to determine whether the subject of a particular certificate is also the person corresponding to a particular sensitive identifier. [STANDARDS-TRACK]

This document describes schema for representing X.509 certificates, X.521 security information, and related elements in directories accessible using the Lightweight Directory Access Protocol (LDAP). The LDAP definitions for these X.509 and X.521 schema elements replace those provided in RFCs 2252 and 2256. [STANDARDS-TRACK]

This document describes the conventions for using the cryptographic algorithms GOST 28147-89, GOST R 34.10-94, GOST R 34.10-2001, and GOST R 34.11-94 with the Cryptographic Message Syntax (CMS). The CMS is used for digital signature, digest, authentication, and encryption of arbitrary message contents. [STANDARDS-TRACK]

This document supplements RFC 3279. It describes encoding formats, identifiers, and parameter formats for the algorithms GOST R 34.10-94, GOST R 34.10-2001, and GOST R 34.11-94 for use in Internet X.509 Public Key Infrastructure (PKI). [STANDARDS-TRACK]

This document describes one certificate extension that explicitly states the Attribute Certificate Policies (ACPs) that apply to a given Attribute Certificate (AC). The goal of this document is to allow relying parties to perform an additional test when validating an AC, i.e., to assess whether a given AC carrying some attributes can be accepted on the basis of references to one or more specific ACPs. [STANDARDS-TRACK]

The protocol conventions described in this document satisfy some of the operational requirements of the Internet Public Key Infrastructure (PKI). This document specifies the conventions for using the Hypertext Transfer Protocol (HTTP/HTTPS) as an interface mechanism to obtain certificates and certificate revocation lists (CRLs) from PKI repositories. Additional mechanisms addressing PKIX operational requirements are specified in separate documents. [STANDARDS-TRACK]

This document defines two Extensible Authentication Protocol (EAP) extended key usage values and a public key certificate extension to carry Wireless LAN (WLAN) System Service identifiers (SSIDs). This document obsoletes RFC 3770. [STANDARDS-TRACK]

This document defines a Public Key Infrastructure (PKI) repository locator service. The service makes use of DNS SRV records defined in accordance with RFC 2782. The service enables certificate-using systems to locate PKI repositories.This memo defines an Experimental Protocol for the Internet community.

This document defines a certificate extension for inclusion of Secure/Multipurpose Internet Mail Extensions (S/MIME) Capabilities in X.509 public key certificates, as defined by RFC 3280. This certificate extension provides an optional method to indicate the cryptographic capabilities of an entity as a complement to the S/MIME Capabilities signed attribute in S/MIME messages according to RFC 3851. [STANDARDS-TRACK]

The Public-Key Infrastructure using X.509 (PKIX) Working Group of the Internet Engineering Task Force (IETF) has defined a number of certificate management protocols. These protocols are primarily focused on X.509v3 public-key certificates. However, it is sometimes desirable to manage certificates in alternative formats as well. This document specifies how such certificates may be requested using the Certificate Request Message Format (CRMF) syntax that is used by several different protocols. It also explains how alternative certificate formats may be incorporated into such popular protocols as PKIX Certificate Management Protocol (PKIX-CMP) and Certificate Management Messages over CMS (CMC). This memo provides information for the Internet community.

This document describes the Certificate Request Message Format (CRMF) syntax and semantics. This syntax is used to convey a request for a certificate to a Certification Authority (CA), possibly via a Registration Authority (RA), for the purposes of X.509 certificate production. The request will typically include a public key and the associated registration information. This document does not define a certificate request protocol. [STANDARDS-TRACK]

This document provides guidance and recommendations to developers building X.509 public-key certification paths within their applications. By following the guidance and recommendations defined in this document, an application developer is more likely to develop a robust X.509 certificate-enabled application that can build valid certification paths across a wide range of PKI environments. This memo provides information for the Internet community.

This document supplements RFC 3279. It describes the conventions for using the RSA Probabilistic Signature Scheme (RSASSA-PSS) signature algorithm, the RSA Encryption Scheme - Optimal Asymmetric Encryption Padding (RSAES-OAEP) key transport algorithm and additional one-way hash functions with the Public-Key Cryptography Standards (PKCS) #1 version 1.5 signature algorithm in the Internet X.509 Public Key Infrastructure (PKI). Encoding formats, algorithm identifiers, and parameter formats are specified. [STANDARDS-TRACK]

This document defines a new form of name, called permanent identifier, that may be included in the subjectAltName extension of a public key certificate issued to an entity.

The permanent identifier is an optional feature that may be used by a CA to indicate that two or more certificates relate to the same entity, even if they contain different subject name (DNs) or different names in the subjectAltName extension, or if the name or the affiliation of that entity stored in the subject or another name form in the subjectAltName extension has changed.

The subject name, carried in the subject field, is only unique for each subject entity certified by the one CA as defined by the issuer name field. However, the new name form can carry a name that is unique for each subject entity certified by a CA. [STANDARDS-TRACK]

This document describes a certificate extension to explicitly state the warranty offered by a Certificate Authority (CA) for the certificate containing the extension. This memo provides information for the Internet community.

This document specifies a 224-bit one-way hash function, called SHA-224. SHA-224 is based on SHA-256, but it uses a different initial value and the result is truncated to 224 bits. This memo provides information for the Internet community.

This document forms a certificate profile for Proxy Certificates, based on X.509 Public Key Infrastructure (PKI) certificates as defined in RFC 3280, for use in the Internet. The term Proxy Certificate is used to describe a certificate that is derived from, and signed by, a normal X.509 Public Key End Entity Certificate or by another Proxy Certificate for the purpose of providing restricted proxying and delegation within a PKI based authentication system. [STANDARDS-TRACK]

This document defines two X.509 v3 certificate extensions. The first binds a list of IP address blocks, or prefixes, to the subject of a certificate. The second binds a list of autonomous system identifiers to the subject of a certificate. These extensions may be used to convey the authorization of the subject to use the IP addresses and autonomous system identifiers contained in the extensions. [STANDARDS-TRACK]

This document forms a certificate profile, based on RFC 3280, for identity certificates issued to natural persons. The profile defines specific conventions for certificates that are qualified within a defined legal framework, named Qualified Certificates. However, the profile does not define any legal requirements for such Qualified Certificates. The goal of this document is to define a certificate profile that supports the issuance of Qualified Certificates independent of local legal requirements. The profile is however not limited to Qualified Certificates and further profiling may facilitate specific local needs. [STANDARDS-TRACK]

This document defines requirements for a baseline time-stamp policy for Time-Stamping Authorities (TSAs) issuing time-stamp tokens, supported by public key certificates, with an accuracy of one second or better. A TSA may define its own policy which enhances the policy defined in this document. Such a policy shall incorporate or further constrain the requirements identified in this document.

This document presents a framework to assist the writers of certificate policies or certification practice statements for participants within public key infrastructures, such as certification authorities, policy authorities, and communities of interest that wish to rely on certificates. In particular, the framework provides a comprehensive list of topics that potentially (at the writer's discretion) need to be covered in a certificate policy or a certification practice statement. This document supersedes RFC 2527.

This document specifies the requirements for Delegated Path Validation

(DPV) and Delegated Path Discovery (DPD) for Public Key Certificates.

It also specifies the requirements for DPV and DPD policy management.

This document specifies algorithm identifiers and ASN.1 encoding formats for digital signatures and subject public keys used in the Internet X.509 Public Key Infrastructure (PKI). Digital signatures are used to sign certificates and certificate revocation list (CRLs). Certificates include the public key of the named subject. [STANDARDS-TRACK]

This document describes the format of a request sent to a Time Stamping Authority (TSA) and of the response that is returned. It also establishes several security-relevant requirements for TSA operation, with regards to processing requests to generate responses. [STANDARDS-TRACK]

This document describes a general Data Validation and Certification Server (DVCS) and the protocols to be used when communicating with it. This memo defines an Experimental Protocol for the Internet community.