Watsen Networks

kent+ietf@watsen.net

Vigil Security, LLC

housley@vigilsec.com

sn3rd

sean@sn3rd.com

Operations NETCONF Working Group zerotouch bootstrap sztp ztp csr pkcs#10 p10 p10cr cmc cmp This draft extends the "get-bootstrapping-data" RPC defined in RFC 8572 to include an optional certificate signing request (CSR), enabling a bootstrapping device to additionally obtain an identity certificate (e.g., an LDevID, from IEEE 802.1AR) as part of the "onboarding information" response provided in the RPC-reply. Editorial Note (To be removed by RFC Editor) This draft contains many placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document. Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements:

• XXXX --> the assigned numerical RFC value for this draft
• AAAA --> the assigned RFC value for I-D.ietf-netconf-crypto-types

Artwork in this document contains a placeholder value for the publication date of this draft. Please apply the following replacement:

• 2020-06-09 --> the publication date of this draft

This document contains references to other drafts in progress, both in the Normative References section, as well as in body text throughout. Please update the following references to reflect their final RFC assignments:

• I-D.ietf-netconf-crypto-types
• I-D.ietf-netconf-keystore
• I-D.ietf-netconf-trust-anchors
• I-D.ietf-netmod-factory-default

Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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 . 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 11 December 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 () in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

• .  Introduction
  • .  Overview
  • .  Terminology
  • .  Requirements Language
• .  The "ietf-sztp-csr" Module
  • .  Data Model Overview
  • .  Example Usage
  • .  YANG Module
• .  Security Considerations
  • .  SZTP-Client Considerations
    • .  Ensuring the Integrity of Asymmetric Private Keys
    • .  Reuse of a Manufacturer-generated Private Key
    • .  Replay Attack Protection
    • .  Connecting to an Untrusted Bootstrap Server
    • .  Selecting the Best Origin Authentication Mechanism
    • .  Clearing the Private Key and Associated Certificate
  • .  SZTP-Server Considerations
    • .  Conveying Proof of Possession to a CA
    • .  Supporting SZTP-Clients that don't trust the SZTP-Server
    • .  YANG Module Considerations
• .  IANA Considerations
  • .  The IETF XML Registry
  • .  The YANG Module Names Registry
• .  References
  • .  Normative References
  • .  Informative References
• Authors' Addresses

Introduction

Overview This draft extends the "get-bootstrapping-data" RPC defined in to include an optional certificate signing request (CSR) , enabling a bootstrapping device to additionally obtain an identity certificate (e.g., an LDevID ) as part of the "onboarding information" response provided in the RPC-reply.

Terminology This document uses the following terms from :

• Bootstrap Server
• Bootstrapping Data
• Conveyed Information
• Device
• Manufacturer
• Onboarding Information
• Signed Data

This document defines the following new terms:

SZTP-client

The term "SZTP-client" refers to a "device" that is using a "bootstrap server" as a source of "bootstrapping data".

SZTP-server

The term "SZTP-server" is an alternative term for "bootstrap server" that is symmetric with the "SZTP-client" term.

Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

The "ietf-sztp-csr" Module This section defines a YANG 1.1 module that augments the "ietf-sztp-bootstrap-server" module defined in and defines a YANG "structure". The augmentation adds two nodes ("csr-support" and "csr") to the "input" parameter of the "get-bootstrapping-data" RPC defined in . The YANG structure, "request-info", defines data returned in the "error-info" node defined in .

Data Model Overview The following tree diagram illustrates the "ietf-sztp-csr" module. The diagram shows the definition of an augmentation adding descendent nodes "csr-support" and "csr" and the definition of a structure called "request-info". In the order of their intended use:

• The "csr-support" node is used by the SZTP-client to signal to the SZTP-server that it supports the ability the generate CSRs, per this specification. The "csr-support" parameter carries details regarding the SZTP-client's ability to generate CSRs.
• The "request-info" structure is used by the SZTP-server to signal back to the SZTP-client its desire to sign a CSR. The "request-info" structure additionally communicates details about the CSR the SZTP-client is to generate.
• The "csr" node is used by the SZTP-client to communicate its CSR to the SZTP-server. Not shown is how the SZTP-server communicates the signed certificate to the SZTP-client; how to do this is discussed later in this document.

To further illustrate how the augmentation and structure defined by the "ietf-sztp-csr" module are used, below are two additional tree diagrams showing these nodes placed where they are used. The following tree diagram illustrates SZTP's "get-bootstrapping-data" RPC with the augmentation in place. The following tree diagram illustrates RESTCONF's "errors" RPC-reply message with the "request-info" structure in place.

Example Usage An SZTP-client implementing this specification would signal to the bootstrap server its willingness to generate a CSR by including the "csr-support" node in its "get-bootstrapping-data" RPC, as illustrated below. REQUEST Assuming the SZTP-server wishes to prompt the SZTP-client to provide a CSR, then it would respond with an HTTP 400 (Bad Request) error code: RESPONSE Upon being prompted to provide a CSR, the SZTP-client would POST another "get-bootstrapping-data" request, but this time including the "csr" node to convey its CSR to the SZTP-server: REQUEST The SZTP-server responds with "onboarding-information" (conveyed encoded inside the "conveyed-information" node) containing a signed identity certificate for the CSR provided by the SZTP-client: RESPONSE How the signed certificate is conveyed inside the onboarding information is outside the scope of this document. Some implementations may choose to convey it inside a script (e.g., SZTP's "pre-configuration-script"), while other implementations convey it inside the SZTP "configuration" node. Following are two examples of conveying the signed certificate inside the "configuration" node. Both examples assume that the SZTP-client understands the "ietf-keystore" module defined in . This first example illustrates the case where the signed certificate is for the same asymmetric key used by the SZTP-client's manufacturer-generated identity certificate (e.g., an IDevID). As such, the configuration needs to associate the newly signed certificate with the existing asymmetric key: This second example illustrates the case where the signed certificate is for a newly generated asymmetric key. As such, the configuration needs to associate the newly signed certificate with the newly generated asymmetric key: In addition to configuring the signed certificate, it is often necessary to also configure the Issuer's signing certificate so that the the device (i.e., STZP-client) can authenticate certificates presented by peer devices signed by the same issuer as its own. While outside the scope of this document, one way to do this would be to use the "ietf-truststore" module defined in .

YANG Module This module augments an RPC defined in , uses a data type defined in , has an normative references to and , and an informative reference to . <CODE BEGINS> file "ietf-sztp-csr@2020-06-09.yang" Authors: Kent Watsen Russ Housley Sean Turner "; description "This module augments the 'get-bootstrapping-data' RPC, defined in the 'ietf-sztp-bootstrap-server' module from SZTP (RFC 8572), enabling the SZTP-client to obtain a signed identity certificate (e.g., an LDevID from IEEE 802.1AR) as part of the SZTP 'onboarding-information' response. Copyright (c) 2020 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here."; revision 2020-06-09 { description "Initial version"; reference "RFC XXXX: Conveying a Certificate Signing Request (CSR) in a Secure Zero Touch Provisioning (SZTP) Bootstrapping Request"; } identity certificate-request-format { description "A base identity for the request formats supported by the SZTP-client. Additional derived identities MAY be defined by future efforts."; } identity p10 { base "certificate-request-format"; description "Indicates that the SZTP-client supports generating requests using the 'CertificationRequest' structure defined in RFC 2986."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7"; } identity cmc { base "certificate-request-format"; description "Indicates that the SZTP-client supports generating requests using a constrained version of the 'Full PKI Request' structure defined in RFC 5272."; reference "RFC 5272: Certificate Management over CMS (CMC)"; } identity cmp { base "certificate-request-format"; description "Indicates that the SZTP-client supports generating requests that contain a PKCS#10 Certificate Signing Request (p10cr) encapsulated in a Nested Message Content (nested), as defined in RFC 4210."; // FIXME: need to describe exactly what the structure // looks like when the origination-authentication // strategy uses an asymmetric-key vs a shared secret. // // e.g., see Sections D.4 and E.7 in RFC 4210 reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 RFC 4210: Internet X.509 Public Key Infrastructure Certificate Management Protocol (CMP)"; } // Protocol-accessible nodes augment "/sztp-svr:get-bootstrapping-data/sztp-svr:input" { description "This augmentation adds the 'csr-support' and 'csr' nodes to the SZTP (RFC 8572) 'get-bootstrapping-data' request message, enabling the SZTP-client to obtain an identity certificate (e.g., an LDevID from IEEE 802.1AR) as part of the onboarding information response provided by the SZTP-server. The 'csr-support' node enables the SZTP-client to indicate that it supports generating certificate signing requests (CSRs), and to provide details around the CSRs it is able to generate. The 'csr' node enables the SZTP-client to relay a CSR to the SZTP-server."; reference "IEEE 802.1AR: IEEE Standard for Local and metropolitan area networks - Secure Device Identity RFC 8572: Secure Zero Touch Provisioning (SZTP)"; container csr-support { presence "Indicates that the SZTP-client is capable of sending CSRs."; description "The 'csr-support' node enables the SZTP-client to indicate that it supports generating certificate signing requests (CSRs), and to provide details around the CSRs it is able to generate. When present, the SZTP-server MAY respond with the HTTP error 400 (Bad Request) with an 'ietf-restconf:errors' document having the 'error-tag' value 'missing-attribute' and the 'error-info' node containing the 'request-info' structure described in this module."; container key-generation { presence "Indicates that the SZTP-client is capable of generating a new asymmetric key pair. If this node is not present, the SZTP-server MAY request a CSR using the asymmetric key associated with the device's existing identity certificate (e.g., an LDevID from IEEE 802.1AR)."; description "Specifies details for the SZTP-client's ability to generate a new asymmetric key pair."; container supported-algorithms { description "A list of public key algorithms supported by the SZTP-client for generating a new key."; leaf-list algorithm-identifier { type binary; min-elements 1; description "An AlgorithmIdentifier, as defined in RFC 2986, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } } } container csr-generation { description "Specifies details for the SZTP-client's ability to generate a certificate signing requests."; container supported-formats { description "A list of certificate request formats supported by the SZTP-client for generating a new key."; leaf-list format-identifier { type identityref { base certificate-request-format; } min-elements 1; description "A certificate request format supported by the SZTP-client."; } } } } container csr { presence "Indicates that the SZTP-client has sent a CSR."; description "The 'csr' node enables the SZTP-client to convey a certificate signing request, using the encoding format selected by the SZT-server's 'request-info' response to the SZTP-client's previously sent 'get-bootstrapping-data' request containing the 'csr-support' node. When present, the SZTP-server SHOULD respond with an SZTP 'onboarding-information' message containing a signed certificate for the conveyed CSR. The SZTP-server MAY alternatively respond with another HTTP error containing another 'request-info', in which case the SZTP-client MUST invalidate the CSR sent in this node."; choice request-type { mandatory true; description "A choice amongst certificate signing request formats. Additional formats MAY be augmented into this 'choice' statement by future efforts."; case p10 { leaf p10 { type ct:csr; description "A CertificationRequest structure, per RFC 2986. Please see 'csr' in RFC AAAA for encoding details."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification RFC AAAA: Common YANG Data Types for Cryptography"; } } case cmc { leaf cmc { type binary; description "A constrained version of the 'Full PKI Request' message defined in RFC 5272, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690. For asymmetric key-based origin authentication of a CSR based on the IDevID's private key for the associated IDevID's public key, the PKIData contains one reqSequence element and no controlSequence, cmsSequence, or otherMsgSequence elements. The reqSequence is the TaggedRequest and it is the tcr CHOICE. The tcr is the TaggedCertificationRequest and it a bodyPartId and the certificateRequest elements. The certificateRequest is signed with the IDevID's private key. For asymmetric key-based origin authentication based on the IDevID's private key that encapsulates a CSR signed by the LDevID's private key, the PKIData contains one cmsSequence element and no controlSequence, reqSequence, or otherMsgSequence elements. The cmsSequence is the TaggedContentInfo and it includes a bodyPartID element and a contentInfo. The contentInfo is a SignedData encapsulating a PKIData with one reqSequence element and no controlSequence, cmsSequence, or otherMsgSequence elements. The reqSequence is the TaggedRequest and it is the tcr CHOICE. The tcr is the TaggedCertificationRequest and it a bodyPartId and the certificateRequest elements. The certificateRequest is signed with the LDevID's private key. For shared secret-based origin authentication of a CSR signed by the LDevID's private key, the PKIData contains one cmsSequence element and no controlSequence, reqSequence, or otherMsgSequence elements. The cmsSequence is the TaggedContentInfo and it includes a bodyPartID element and a contentInfo. The contentInfo is an AuthenticatedData encapsulating a PKIData with one reqSequence element and no controlSequence, cmsSequence, or otherMsgSequence elements. The reqSequence is the TaggedRequest and it is the tcr CHOICE. The tcr is the TaggedCertificationRequest and it a bodyPartId and the certificateRequest elements. The certificateRequest is signed with the LDevID's private key."; reference "RFC 5272: Certificate Management over CMS (CMC) ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } } case cmp { leaf cmp { type binary; description "A PKIMessage structure, as defined in RFC 4210, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690. The PKIMessage structure contains a PKCS#10 Certificate Signing Request (p10cr), as defined in RFC 2986, encapsulated in a Nested Message Content (nested) structure, as defined in RFC 4210.”; For asymmetric key-based origin authentication of a CSR based on the IDevID's private key for the associated IDevID's public key, PKIMessages contains one PKIMessage with one body element, a header element that is an empty sequence, and no protection or extraCerts elements. The body element contains a p10cr CHOICE. For asymmetric key-based origin authentication based on the IDevID's private key that encapsulates a CSR signed by the LDevID's private key, PKIMessages contains one PKIMessage with one header element, one body element, one protection element, and one extraCerts element. The header element contains pvno, sender, recipient, and protectionAlg elements and no other elements. The body element contains the nested CHOICE. The nested element's PKIMessages contains one PKIMessage with one body element, one header element that is an empty sequence, and no protection or extraCerts elements. The nested element's body element contains a p10cr CHOICE. The protection element contains the digital signature generated with the IDevID's private key. The extraCerts element contains the IDevID certificate. For shared secret-based origin authentication of a CSR signed by the LDevID's private key, PKIMessages contains one PKIMessage with one header element, one body element, one protection element, and no extraCerts element. The header element contains pvno, sender, recipient, and protectionAlg elements and no other elements. The body element contains the nested CHOICE. The nested element's PKIMessages contains one PKIMessage with one body element, one header element that is an empty sequence, and no protection or extraCerts elements. The body element contains a p10cr CHOICE. The protection element contains the MAC value generated with the shared secret."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 RFC 4210: Internet X.509 Public Key Infrastructure Certificate Management Protocol (CMP) ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } } } } } sx:structure request-info { container key-generation { presence "Indicates that the SZTP-client is to generate a new asymmetric key. If missing, then the SZTP-client MUST reuse the key associated with its existing identity certificate (e.g., IDevID). This leaf MUST only appear if the SZTP-clients 'csr-support' included the 'key-generation' node."; description "Specifies details for the key that the SZTP-client is to generate."; container selected-algorithm { description "The key algorithm selected by the SZTP-server. The algorithm MUST be one of the algorithms specified by the 'supported-algorithms' node in the SZTP-client's request message."; leaf algorithm-identifier { type binary; mandatory true; description "An AlgorithmIdentifier, as defined in RFC 2986, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } } } container csr-generation { description "Specifies details for the CSR that the SZTP-client is to generate."; container selected-format { description "The CSR format selected by the SZTP-server. The format MUST be one of the formats specified by the 'supported-formats' node in the SZTP-client's request message."; leaf format-identifier { type identityref { base certificate-request-format; } mandatory true; description "A certificate request format to be used by the SZTP-client."; } } } leaf cert-req-info { type binary; description "A CertificationRequestInfo structure, as defined in RFC 2986, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690. Enables the SZTP-server to provide a fully-populated CertificationRequestInfo structure that the SZTP-client only needs to sign in order to generate the complete 'CertificationRequest' structure to send to SZTP-server in its next 'get-bootstrapping-data' request message. When provided, the SZTP-client SHOULD use this structure to generate its CSR; failure to do so MAY result in another 400 (Bad Request) response. When not provided, the SZTP-client SHOULD generate a CSR using the same structure defined in its existing identity certificate (e.g., IDevID). It is an error if the 'AlgorithmIdentifier' field contained inside the 'SubjectPublicKeyInfo' field does not match the algorithm identified by the 'selected-algorithm' node."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } } } ]]> <CODE ENDS>

Security Considerations This document builds on top of the solution presented in and therefore all the Security Considerations discussed in RFC 8572 apply here as well.

SZTP-Client Considerations

Ensuring the Integrity of Asymmetric Private Keys The private key the SZTP-client uses for the dynamically-generated identity certificate MUST be protected from inadvertent disclosure in order to prevent identity fraud. The security of this private key is essential in order to ensure the associated identity certificate can be used as a root of trust. It is RECOMMENDED that devices are manufactured with an HSM (hardware security module), such as a TPM (trusted platform module), to generate and forever contain the private key within the security perimeter of the HSM. In such cases, the private key, and its associated certificates, MAY have long validity periods. In cases where the device does not possess an HSM, or otherwise is unable to use an HSM for the private key, it is RECOMMENDED to regenerate the private key (and associated identity certificates) periodically. Details for how to generate a new private key and associate a new identity certificate are outside the scope of this document.

Reuse of a Manufacturer-generated Private Key It is RECOMMENDED in that devices are shipped from manufacturing with a secure device identity certificate (e.g., an IDevID, from ). It is also RECOMMENDED that the private key for these necessarily long-lived certificates be stored in an HSM, such as a TPM. Lastly, per the previous consideration, when devices generate a new private key, it is also RECOMMENDED that the private key is protected by the HSM. However, it is understood that space on an HSM chip may be limited, potentially to the point of not being able to store an additional private key for the CSR described in this document, and that it may not be possible to store hardware-protected keys outside the TPM (e.g., a TPM-encrypted key stored in non-volatile memory). In such cases, it is RECOMMENDED to reuse the existing hardware-protected private key rather than generate a second private key outside of protection afforded by the hardware.

Replay Attack Protection This RFC enables an SZTP-client to announce an ability to generate new key to use for its CSR. When the SZTP-server responds with a request for the device to generate a new key, it is essential that the device actually generates a new key. Generating a new key each time enables the random bytes used to create the key to serve the dual-purpose of also acting like a "nonce" used in other mechanisms to detect replay attacks. When a fresh public/private key pair is generated for the request, confirmation to the SZTP-client that the response has not been replayed is enabled by the SZTP-client's fresh public key appearing in the signed certificate provided by the SZTP-server. When a public/private key pair associated with the IDevID used for the request, there may not be confirmation to the SZTP-client that the response has not been replayed; however, the worst case result is a lost certificate that is associated to the private key known only to the SZTP-client.

Connecting to an Untrusted Bootstrap Server allows SZTP-clients to connect to untrusted SZTP-servers, by blindly authenticating the SZTP-server's TLS end-entity certificate. As is discussed in , in such cases the SZTP-client MUST assert that the bootstrapping data returned is signed, if the SZTP-client is to trust it. However, the HTTP error message used in this document cannot be signed data, as described in RFC 8572. Therefore, the solution presented in this document cannot be used when the SZTP-client connects to an untrusted SZTP-server. Consistent with the recommendation presented in , SZTP-clients SHOULD NOT passed the "csr-support" input parameter to an untrusted SZTP-server. SZTP-clients SHOULD pass instead the "signed-data-preferred" input parameter, as discussed in .

Selecting the Best Origin Authentication Mechanism When generating a new key, it is important that the client be able to provide additional proof to the CA that it was the entity that generated the key. All of the certificate request formats defined in this document (e.g., CMS, CMP, etc.), not including a raw PKCS#10, support origin authentication. These formats support origin authentication using both PKI and shared secret. Typically only one possible origin authentication mechanism can possibly be used but, in the case that the SZTP-client authenticates itself using both TLS-level (e.g., IDevID) and HTTP-level credentials (e.g., Basic), as is allowed by , then the SZTP-client may need to choose between the two options. In the case the SZTP-client must choose between the asymmetric key option versus a shared secret for origin authentication, it is RECOMMENDED that the SZTP-client choose using the asymmetric key option.

Clearing the Private Key and Associated Certificate Unlike a manufacturer-generated identity certificate (e.g., IDevID), the deployment-generated identity certificate (e.g., LDevID) and the associated private key (assuming a new private key was generated for the purpose), are considered user data and SHOULD be cleared whenever the device is reset to its factory default state, such as by the "factory-reset" RPC defined in .

SZTP-Server Considerations

Conveying Proof of Possession to a CA

Supporting SZTP-Clients that don't trust the SZTP-Server allows SZTP-clients to connect to untrusted SZTP-servers, by blindly authenticating the SZTP-server's TLS end-entity certificate. As is recommended in in this document, in such cases, SZTP-clients SHOULD pass the "signed-data-preferred" input parameter. The reciprocal of this statement is that SZTP-servers, wanting to support SZTP-clients that don't trust them, SHOULD support the "signed-data-preferred" input parameter, as discussed in .

YANG Module Considerations The recommended format for documenting the Security Considerations for YANG modules is described in . However, the module defined in this document only augments two input parameters into the "get-bootstrapping-data" RPC in , and therefore only needs to point to the relevant Security Considerations sections in that RFC.

• Security considerations for the "get-bootstrapping-data" RPC are described in .
• Security considerations for the "input" parameters passed inside the "get-bootstrapping-data" RPC are described in .

IANA Considerations

The IETF XML Registry This document registers one URI in the "ns" subregistry of the IETF XML Registry maintained at . Following the format in , the following registration is requested:

The YANG Module Names Registry This document registers one YANG module in the YANG Module Names registry maintained at . Following the format defined in , the below registration is requested:

References Normative References This document presents a YANG 1.1 (RFC 7950) module defining identities, typedefs, and groupings useful to cryptographic applications. Editorial Note (To be removed by RFC Editor) This draft contains placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document. Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: o "AAAA" --> the assigned RFC value for this draft Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: o "2020-05-20" --> the publication date of this draft The following Appendix section is to be removed prior to publication: o Appendix B. Change Log Note to Reviewers (To be removed by RFC Editor) This document presents a YANG module or modules that is/are part of a collection of drafts that work together to produce the ultimate goal of the NETCONF WG: to define configuration modules for NETCONF client and servers, and RESTCONF client and servers. The relationship between the various drafts in the collection is presented in the below diagram. crypto-types ^ ^ / \ / \ trust-anchors keystore ^ ^ ^ ^ | +---------+ | | | | | | | +------------+ | tcp-client-server | / | | ^ ^ ssh-client-server | | | | ^ tls-client-server | | | ^ ^ http-client-server | | | | | ^ | | | +-----+ +---------+ | | | | | | | | +-----------|--------|--------------+ | | | | | | | | +-----------+ | | | | | | | | | | | | | | | | | netconf-client-server restconf-client-server Full draft names and link to drafts: o draft-ietf-netconf-crypto-types (html [1]) o draft-ietf-netconf-trust-anchors (html [2]) o draft-ietf-netconf-keystore (html [3]) o draft-ietf-netconf-tcp-client-server (html [4]) o draft-ietf-netconf-ssh-client-server (html [5]) o draft-ietf-netconf-tls-client-server (html [6]) o draft-ietf-netconf-http-client-server (html [7]) o draft-ietf-netconf-netconf-client-server (html [8]) o draft-ietf-netconf-restconf-client-server (html [9]) Work in Progress International Telecommunication Union In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. This memo represents a republication of PKCS #10 v1.7 from RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, and change control is retained within the PKCS process. The body of this document, except for the security considerations section, is taken directly from the PKCS #9 v2.0 or the PKCS #10 v1.7 document. This memo provides information for the Internet community. YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK] YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF). RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. This document presents a technique to securely provision a networking device when it is booting in a factory-default state. Variations in the solution enable it to be used on both public and private networks. The provisioning steps are able to update the boot image, commit an initial configuration, and execute arbitrary scripts to address auxiliary needs. The updated device is subsequently able to establish secure connections with other systems. For instance, a device may establish NETCONF (RFC 6241) and/or RESTCONF (RFC 8040) connections with deployment-specific network management systems. Informative References This document defines a YANG 1.1 module called "ietf-keystore" that enables centralized configuration of both symmetric and asymmetric keys. The secret value for both key types may be encrypted. Asymmetric keys may be associated with certificates. Notifications are sent when certificates are about to expire. Editorial Note (To be removed by RFC Editor) This draft contains placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document. Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: o "AAAA" --> the assigned RFC value for draft-ietf-netconf-crypto- types o "CCCC" --> the assigned RFC value for this draft Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: o "2020-05-20" --> the publication date of this draft The following Appendix section is to be removed prior to publication: o Appendix A. Change Log Note to Reviewers (To be removed by RFC Editor) This document presents a YANG module or modules that is/are part of a collection of drafts that work together to produce the ultimate goal of the NETCONF WG: to define configuration modules for NETCONF client and servers, and RESTCONF client and servers. The relationship between the various drafts in the collection is presented in the below diagram. crypto-types ^ ^ / \ / \ trust-anchors keystore ^ ^ ^ ^ | +---------+ | | | | | | | +------------+ | tcp-client-server | / | | ^ ^ ssh-client-server | | | | ^ tls-client-server | | | ^ ^ http-client-server | | | | | ^ | | | +-----+ +---------+ | | | | | | | | +-----------|--------|--------------+ | | | | | | | | +-----------+ | | | | | | | | | | | | | | | | | netconf-client-server restconf-client-server Full draft names and link to drafts: o draft-ietf-netconf-crypto-types (html [1]) o draft-ietf-netconf-trust-anchors (html [2]) o draft-ietf-netconf-keystore (html [3]) o draft-ietf-netconf-tcp-client-server (html [4]) o draft-ietf-netconf-ssh-client-server (html [5]) o draft-ietf-netconf-tls-client-server (html [6]) o draft-ietf-netconf-http-client-server (html [7]) o draft-ietf-netconf-netconf-client-server (html [8]) o draft-ietf-netconf-restconf-client-server (html [9]) Work in Progress This document defines a YANG 1.1 data model for configuring globally- accessible bags of certificates and public keys that can be referenced by other data models for trust. Editorial Note (To be removed by RFC Editor) This draft contains placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document. Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: o "AAAA" --> the assigned RFC value for draft-ietf-netconf-crypto- types o "BBBB" --> the assigned RFC value for this draft Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: o "2020-05-20" --> the publication date of this draft The following Appendix section is to be removed prior to publication: o Appendix A. Change Log Note to Reviewers (To be removed by RFC Editor) This document presents a YANG module or modules that is/are part of a collection of drafts that work together to produce the ultimate goal of the NETCONF WG: to define configuration modules for NETCONF client and servers, and RESTCONF client and servers. The relationship between the various drafts in the collection is presented in the below diagram. crypto-types ^ ^ / \ / \ trust-anchors keystore ^ ^ ^ ^ | +---------+ | | | | | | | +------------+ | tcp-client-server | / | | ^ ^ ssh-client-server | | | | ^ tls-client-server | | | ^ ^ http-client-server | | | | | ^ | | | +-----+ +---------+ | | | | | | | | +-----------|--------|--------------+ | | | | | | | | +-----------+ | | | | | | | | | | | | | | | | | netconf-client-server restconf-client-server Full draft names and link to drafts: o draft-ietf-netconf-crypto-types (html [1]) o draft-ietf-netconf-trust-anchors (html [2]) o draft-ietf-netconf-keystore (html [3]) o draft-ietf-netconf-tcp-client-server (html [4]) o draft-ietf-netconf-ssh-client-server (html [5]) o draft-ietf-netconf-tls-client-server (html [6]) o draft-ietf-netconf-http-client-server (html [7]) o draft-ietf-netconf-netconf-client-server (html [8]) o draft-ietf-netconf-restconf-client-server (html [9]) Work in Progress This document defines a YANG data model with the "factory-reset" RPC to allow clients to reset a server back to its factory default condition. It also defines an optional "factory-default" datastore to allow clients to read the factory default configuration for the device. The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in RFC 8342. Work in Progress This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas. This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language. This memo provides guidelines for authors and reviewers of specifications containing YANG modules. Recommendations and procedures are defined, which are intended to increase interoperability and usability of Network Configuration Protocol (NETCONF) and RESTCONF protocol implementations that utilize YANG modules. This document obsoletes RFC 6087. IEEE SA-Standards Board

Authors' Addresses Watsen Networks

kent+ietf@watsen.net

Vigil Security, LLC

housley@vigilsec.com

sn3rd

sean@sn3rd.com