--- 1/draft-ietf-lamps-cmp-updates-00.txt 2020-03-04 06:13:22.526641994 -0800 +++ 2/draft-ietf-lamps-cmp-updates-01.txt 2020-03-04 06:13:22.582643414 -0800 @@ -1,19 +1,19 @@ LAMPS Working Group H. Brockhaus Internet-Draft Siemens -Updates: 4210 (if approved) February 16, 2020 +Updates: 4210 (if approved) March 4, 2020 Intended status: Standards Track -Expires: August 19, 2020 +Expires: September 5, 2020 CMP Updates - draft-ietf-lamps-cmp-updates-00 + draft-ietf-lamps-cmp-updates-01 Abstract This document contains a set of updates to the base syntax of Certificate Management Protocol (CMP) version 2. This document updates RFC 4210. Specifically, the CMP services updated in this document comprise the enabling of using EnvelopedData instead of EncryptedValue and the definition of extended key usages to identify certificates of CMP @@ -27,21 +27,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on August 19, 2020. + This Internet-Draft will expire on September 5, 2020. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -52,55 +52,58 @@ described in the Simplified BSD License. Table of Contents 1. History of changes . . . . . . . . . . . . . . . . . . . . . 2 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Convention and Terminology . . . . . . . . . . . . . . . 3 3. Updates to RFC 4210 - Certificate Management Protocol (CMP) . 4 3.1. New Section 1.1. - Changes since RFC 4210 . . . . . . . . 4 3.2. New Section 4.5 - Extended Key Usage . . . . . . . . . . 5 - 3.3. Replace Section 5.1.3.4 - Multiple Protection . . . . . . 6 - 3.4. Replace Section 5.2.2. - Encrypted Values . . . . . . . . 7 + 3.3. Replace Section 5.1.3.4 - Multiple Protection . . . . . . 7 + 3.4. Replace Section 5.2.2. - Encrypted Values . . . . . . . . 8 3.5. Update Section 5.3.4. - Certification Response . . . . . 9 - 3.6. Replace Section 5.3.19.9. - Revocation Passphrase . . . . 9 + 3.6. Replace Section 5.3.19.9. - Revocation Passphrase . . . . 10 3.7. Update Section 5.3.22 - Polling Request and Response . . 10 3.8. Update Appendix B - The Use of Revocation Passphrase . . 11 3.9. Update Appendix C - Request Message Behavioral Clarifications . . . . . . . . . . . . . . . . . . . . . 12 3.10. Update Appendix D.4. - Initial Registration/Certification - (Basic Authenticated Scheme) . . . . . . . . . . . . . . 12 - 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 + (Basic Authenticated Scheme) . . . . . . . . . . . . . . 13 + 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 - 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 - 7.1. Normative References . . . . . . . . . . . . . . . . . . 13 - 7.2. Informative References . . . . . . . . . . . . . . . . . 14 - Appendix A. ASN.1 Modules . . . . . . . . . . . . . . . . . . . 14 - Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 15 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 + 7.1. Normative References . . . . . . . . . . . . . . . . . . 14 + 7.2. Informative References . . . . . . . . . . . . . . . . . 15 + Appendix A. ASN.1 Modules . . . . . . . . . . . . . . . . . . . 15 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 16 1. History of changes - From draft-brockhaus-lamps-cmp-updates-03 -> draft-brockhaus-lamps- - cmp-updates-03: - - o Changes required to reflect WG adoption + From version 00 -> 01: o Minor changes in wording + From draft-brockhaus-lamps-cmp-updates-03 -> draft-ietf-lamps-cmp- + updates-00: + + o Changes required to reflect WG adoption + From version 02 -> 03: o Added some clarification in Section 3.1 From version 01 -> 02: o Added clarification to section on multiple protection + o Added clarification on new EKUs after some exchange with Tomas Gustavsson o Reused OIDs from RFC 6402 [RFC6402] as suggested by Sean Turner at IETF 106 o Added clarification on the field containing the key identifier for a revocation passphrase o Minor changes in wording @@ -116,21 +119,21 @@ o Minor generalization in RFC 4210 [RFC4210] Sections 5.1.3.4 and 5.3.22 o Minor changes in wording 2. Introduction While using CMP [RFC4210] in industrial and IoT environments and developing the Lightweight CMP Profile - [I-D.brockhaus-lamps-lightweight-cmp-profile] some limitations were + [I-D.ietf-lamps-lightweight-cmp-profile] some limitations were identified in the original CMP specification. This document updates RFC 4210 [RFC4210] to overcome these limitations. In general, this document aims to improve the crypto agility of CMP to be flexible to react on future advances in cryptography. This document also introduces new extended key usages to identify CMP endpoints on registration and certification authorities. 2.1. Convention and Terminology @@ -157,55 +160,62 @@ an EE. The KGA could be co-located with an RA or a CA. EE: End entity, a user, device, or service that holds a PKI certificate. An identifier for the EE is given as its subject of the certificate. 3. Updates to RFC 4210 - Certificate Management Protocol (CMP) 3.1. New Section 1.1. - Changes since RFC 4210 - The following subsections describe feature updates to RFC 4210 + The following subsection describes feature updates to RFC 4210 [RFC4210]. They are always related to the base specification. Hence references to the original sections in RFC 4210 [RFC4210] are used whenever possible. Insert this section at the end of the current Section 1. - The following updates are made in draft-brockhaus-lamps-cmp-updates: + 1.1 Changes since RFC 4210 + + The following updates are made in draft-ietf-lamps-cmp-updates: o Add new extended key usages for different CMP server types, e.g. registration authority and certification authority, to express the authorization of the entity identified in the certificate containing the respective extended key usage extension to act as - the indicated PKI management component. + the indicated PKI management entity. o Extend the description of multiple protection to cover additional use cases, e.g., batch processing of messages. - o Offering EnvelopedData as another choice next to EncryptedValue to - extend crypto agility in CMP. Note that according to RFC 4211 - [RFC4211] section 2.1.9 the use of the EncryptedValue structure - has been deprecated in favor of the EnvelopedData structure. - RFC 4211 [RFC4211] offers the EncryptedKey structure, a choice of - EncryptedValue and EnvelopedData for migration to EnvelopedData. - For reasons of completeness and consistency the exchange of - EncryptedValue is performed for all usages in RFC 4210 [RFC4210]. - - This includes the protection of centrally generated private keys, - encryption of certificates, and revocation passphrases. + o Offering EnvelopedData as the prefered choice next to + EncryptedValue to extend crypto agility in CMP. Note that + according to RFC 4211 [RFC4211] section 2.1.9 the use of the + EncryptedValue structure has been deprecated in favor of the + EnvelopedData structure. RFC 4211 [RFC4211] offers the + EncryptedKey structure, a choice of EncryptedValue and + EnvelopedData for migration to EnvelopedData. For reasons of + completeness and consistency the exchange of EncryptedValue is + performed for all usages in RFC 4210 [RFC4210]. This includes the + protection of centrally generated private keys, encryption of + certificates, and revocation passphrases. o Extend the usage of polling also to p10cr messages. 3.2. New Section 4.5 - Extended Key Usage - Insert this section. + The following subsection describes new extended key usages for + different CMP server typesspecitied in RFC 4210 [RFC4210]. + + Insert this section at the end of the current Section 4. + + 4.5 Extended Key Usage The Extended Key Usage (EKU) extension indicates the purposes for which the certified public key may be used. It therefore restricts the use of a certificate to specific applications. A CA may want to delegate parts of their duties to other PKI management entities. The mechanism to prove this delegation explained in this section offers zero-touch means to check the authorization of such delegation. Such delegation could also be expressed by other means, e.g., explicit configuration. @@ -230,59 +240,63 @@ whether use CMC or CMP as certificate management protocol, the same OIDs SHALL be used for a cmpCA and a cmpRA. < TBD: It needs to be clarified, if the Name and Description of the OIDs can be adapted or extended to avoid confusion as they currently only refer to CMC endpoints. > The description of the PKI management entity for each of the EKUs is as follows: - CMP Certification Authorities are CMP endpoints on CA equipment as - described in section 3.1.1.2. The key used in the context of CMP - management operations, especially CMP message protection, need not be - the same key that signs the certificates. It is necessary, however, - to ensure that the entity acting as cmpCA is authorized to do so. - Therefore, the cmpCA MUST do one of the following, + cmpCA: CMP Certification Authorities are CMP endpoints on CA + equipment as described in section 3.1.1.2. The key used in + the context of CMP management operations, especially CMP + message protection, need not be the same key that signs the + certificates. It is necessary, however, to ensure that the + entity acting as cmpCA is authorized to do so. Therefore, + the cmpCA MUST do one of the following, - o use the CA private key on the CMP endpoint, or + * use the CA private key on the CMP endpoint, or - o explicitly designate this authority to another entity. + * explicitly designate this authority to another entity. - For automatic validation of such delegation it MUST be indicated by - the id-kp-cmpCA extended key usage. This extended key usage MUST be - placed into the certificate used on the CA equipment and the CA that - delegates this role MUST issue the cmpCA certificate. + For automatic validation of such delegation it MUST be + indicated by the id-kp-cmpCA extended key usage. This + extended key usage MUST be placed into the certificate used + on the CA equipment and the CA that delegates this role MUST + issue the cmpCA certificate. Note: Using a separate key pair for protecting CMP management - operations at the CA decreases the number of operations of the - private key used to sign certificates. + operations at the CA decreases the number of operations of + the private key used to sign certificates. - CMP Registration Authorities are CMP endpoints on RA equipment as - described in section 3.1.1.3. A cmpRA is identified by the id-kp- - cmpRA extended key usage. This extended key usage is placed into RA - certificates. The CA that delegated this role is identified by the - CA that issued the cmpRA certificate. + cmpRA: CMP Registration Authorities are CMP endpoints on RA + equipment as described in Section 3.1.1.3. A cmpRA is + identified by the id-kp-cmpRA extended key usage. This + extended key usage is placed into RA certificates. The CA + that delegated this role is identified by the CA that issued + the cmpRA certificate. - CMP Key Generation Authorities are identified by the id-kp-cmpKGA - extended key usage. Though the cmpKGA knows the private key it - generated on behalf of the end entity, this is a very sensible - service and needs specific authorization. This authorization is - either with the CA certificate itself, or indicated by placing the - id-kp-cmpKGA extended key usage into the cmpRA or cmpCA certificate - used to authenticate the origin of the private key to express the - authorization to offer this service. + cmpKGA: CMP Key Generation Authorities are identified by the id-kp- + cmpKGA extended key usage. Though the cmpKGA knows the + private key it generated on behalf of the end entity. This + is a very sensible service and needs specific authorization. + This authorization is either with the CA certificate itself, + or indicated by placing the id-kp-cmpKGA extended key usage + into the cmpRA or cmpCA certificate used to authenticate the + origin of the private key, and to express the authorization + to offer this service. Note: In device PKIs, especially those issuing IDevID certificates, CA may have very long validity (including the GeneralizedTime value 99991231235959Z to indicate a not well-defined expiration date as - specified in IEEE 802.1AR section 8.5 [IEEE802.1AR] and RFC 5280 + specified in IEEE 802.1AR Section 8.5 [IEEE802.1AR] and RFC 5280 Section 4.1.2.5 [RFC5280]). Such validity periods SHOULD NOT be used for protection of CMP messages. Certificates for delegated CMP message protection (cmpCA, cmpRA, cmpKGA) MUST NOT use indefinite expiration date. 3.3. Replace Section 5.1.3.4 - Multiple Protection Section 5.1.3.4 of RFC 4210 [RFC4210] describes the nested message. This document opens the usage of nested messages also for batch transport of PKI messages between different PKI management entities. @@ -295,51 +309,51 @@ certificates shared between the RA and the CA). There are different use cases for such multi protected messages. o The RA confirms the validation and authorization of a message and forwards the original message unchanged. o The RA collects several messages and forwards them in a batch. This can for instance be used to bridge an off-line connection between two PKI management entities. In communication to the CA request messages and in communication from the CA response or - announcement messages will be collected in the batch. + announcement messages will be collected in such batch. o The RA modifies the message(s) in some way (e.g., add or modify particular field values or add new extensions) before forwarding them, then it MAY create its own desired PKIBody. In case the changes made by the RA to PKIMessage breaks the POP, the RA MUST either set the POP RAVerified or include the original PKIMessage from the EE in the generalInfo field of PKIHeader of the nested message (to force the CA to check POP on the original message). The infoType to be used in this situation is {id-it 15} (see Section 5.3.19 for the value of id-it) and the infoValue is PKIMessages (contents MUST be in the same order as the requests in PKIBody). For simplicity reasons, if batching is used in combination with inclusion of the original PKIMessage in the generalInfo field, all messages in the batch MUST be of the same type (e.g., ir). These use cases are accomplished by nesting the messages sent by the - end entity within a new PKI message. The structure used is as + PKI entity within a new PKI message. The structure used is as follows. NestedMessageContent ::= PKIMessages (The use of PKIMessages, a SEQUENCE OF PKIMessage, lets the RA batch the requests of several EEs in a single new message.) 3.4. Replace Section 5.2.2. - Encrypted Values Section 5.2.2 of RFC 4210 [RFC4210] describes the usage of EncryptedValue to transport encrypted data. This document extends - the encryption of data to also use EnvelopedData. + the encryption of data to preferably use EnvelopedData. Replace the text of the section with the following text. Where encrypted data (restricted, in this specification, to be either private keys, certificates, or passwords) are sent in PKI messages, the EncryptedKey data structure is used. EncryptedKey ::= CHOICE { encryptedValue EncryptedValue, -- deprecated envelopedData [0] EnvelopedData } @@ -353,24 +367,24 @@ EnvelopedData. The EncryptedKey data structure is used in CMP to either transport a private key, certificate or revocation passphrase in encrypted form. EnvelopedData is used as follows: o Contains only one recepientInfo structure because the content is encrypted only for one recipient. - o Contains private key in a SignedData structure as specified in CMS - section 5 [RFC5652] signed by the Key Generation Authority. + o Contains a private key in a SignedData structure as specified in + CMS section 5 [RFC5652] signed by the Key Generation Authority. - o Contains certificate or revocation passphrase directly in the + o Contains a certificate or revocation passphrase directly in the encryptedContent field. Note: When transferring a centrally generated private key in a certificate response message to the EE, the algorithm identifier and the associated public key will anyhow be transported in this response message. Therefore, the private key will not be delivered in a key package structure as specified in [RFC5958] and [RFC6032]. But the wrapping of the private key in a SignedData structure that is wrapped in the EnvelopedData structure as specified in [RFC6032] is applied. @@ -480,21 +494,21 @@ one or more of the pending certificates is ready; otherwise, it will return a pollRep. 3 If the EE receives a pollRep, it will wait for at least as long as the checkAfter value before sending another pollReq. 4 If an ip, cp, or kup is received in response to a pollReq, then it will be treated in the same way as the initial response. Note: A p10cr message contains exactly one CertificationRequestInfo - data structure as specified in PKCS#10 [RFC2986] but not certificate + data structure as specified in PKCS#10 [RFC2986] but no certificate request number. Therefore, the certReqId MUST be set to 0 in all following messages of this transaction. 3.8. Update Appendix B - The Use of Revocation Passphrase Appendix B of RFC 4210 [RFC4210] describes the usage of the revocation passphrase. As this document updates RFC 4210 [RFC4210] to utilize the parent structure EncryptedKey instead of EncryptedValue as described in Section 3.1 above, the description is updated accordingly. @@ -504,24 +518,24 @@ o The OID and value specified in Section 5.3.19.9 of RFC 4210 [RFC4210] MAY be sent in a GenMsg message at any time, or MAY be sent in the generalInfo field of the PKIHeader of any PKIMessage at any time. (In particular, the EncryptedKey as described in section 5.2.2 may be sent in the header of the certConf message that confirms acceptance of certificates requested in an initialization request or certificate request message.) This conveys a revocation passphrase chosen by the entity (i.e., for use of EnvelopedData this is in the decrypted bytes of - encryptedContent of the EnvelopedData structure and for use of - EncryptedValue this is in the decrypted bytes of the encValue - field) to the relevant CA/RA; furthermore, the transfer is - accomplished with appropriate confidentiality characteristics. + encryptedContent field and for use of EncryptedValue this is in + the decrypted bytes of the encValue field) to the relevant CA/RA; + furthermore, the transfer is accomplished with appropriate + confidentiality characteristics. Replace the third bullet point of this section with the following text. o When using EnvelopedData the unprotectedAttrs and when using EncryptedValue the valueHint field MAY contain a key identifier (chosen by the entity, along with the passphrase itself) to assist in later retrieval of the correct passphrase (e.g., when the revocation request is constructed by the entity and received by the CA/RA). @@ -538,24 +552,24 @@ [RFC4210] to utilize the parent structure EncryptedKey instead of EncryptedValue as described in Section 3.1 above, the description is updated accordingly. Replace the note coming after the ASN.1 syntax of POPOPrivKey of this section with the following text. -- ********** -- * the type of "thisMessage" is given as BIT STRING in RFC 4211 -- * [RFC4211]; it should be "EncryptedKey" (in accordance with - -- * Section 5.2.2, "Encrypted Values", of this specification). - -- * Therefore, this document makes the behavioral clarification of - -- * specifying that the contents of "thisMessage" MUST be encoded - -- * either as EnvelopedData or EncryptedValue (only for backward + -- * Section 5.2.2 of this specification). Therefore, this document + -- * makes the behavioral clarification of specifying that the + -- * contents of "thisMessage" MUST be encoded either as + -- * "EnvelopedData" or "EncryptedValue" (only for backward -- * compatibility) and then wrapped in a BIT STRING. This allows -- * the necessary conveyance and protection of the private key -- * while maintaining bits-on-the-wire compatibility with RFC 4211 -- * [RFC4211]. -- ********** 3.10. Update Appendix D.4. - Initial Registration/Certification (Basic Authenticated Scheme) Appendix D.4 of RFC 4210 [RFC4210] provides the initial registration/ @@ -626,24 +640,24 @@ [RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, DOI 10.17487/RFC5652, September 2009, . [RFC6402] Schaad, J., "Certificate Management over CMS (CMC) Updates", RFC 6402, DOI 10.17487/RFC6402, November 2011, . 7.2. Informative References - [I-D.brockhaus-lamps-lightweight-cmp-profile] + [I-D.ietf-lamps-lightweight-cmp-profile] Brockhaus, H., Fries, S., and D. Oheimb, "Lightweight CMP - Profile", draft-brockhaus-lamps-lightweight-cmp-profile-03 - (work in progress), January 2020. + Profile", draft-ietf-lamps-lightweight-cmp-profile-00 + (work in progress), February 2020. [RFC5958] Turner, S., "Asymmetric Key Packages", RFC 5958, DOI 10.17487/RFC5958, August 2010, . [RFC6032] Turner, S. and R. Housley, "Cryptographic Message Syntax (CMS) Encrypted Key Package Content Type", RFC 6032, DOI 10.17487/RFC6032, December 2010, .