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Operations NETCONF Working Group 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:

• 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:

• 2022-07-07 --> the publication date of this draft

The following Appendix section is to be removed prior to publication:

• . Change Log

Introduction This document presents a YANG 1.1 module defining identities, typedefs, and groupings useful to cryptographic applications.

Relation to other RFCs This document presents one or more YANG modules that are part of a collection of RFCs that work together to, ultimately, enable the configuration of the clients and servers of both the NETCONF and RESTCONF protocols. The modules have been defined in a modular fashion to enable their use by other efforts, some of which are known to be in progress at the time of this writing, with many more expected to be defined in time. The normative dependency relationship between the various RFCs in the collection is presented in the below diagram. The labels in the diagram represent the primary purpose provided by each RFC. Hyperlinks to each RFC are provided below the diagram. Label to RFC Mapping

Label in Diagram	Originating RFC
crypto-types
truststore
keystore
tcp-client-server
ssh-client-server
tls-client-server
http-client-server
netconf-client-server
restconf-client-server

Specification 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.

Adherence to the NMDA This document is compliant with the Network Management Datastore Architecture (NMDA) . It does not define any protocol accessible nodes that are "config false".

Conventions Various examples used in this document use a placeholder value for binary data that has been base64 encoded (e.g., "BASE64VALUE="). This placeholder value is used as real base64 encoded structures are often many lines long and hence distracting to the example being presented.

The "ietf-crypto-types" Module This section defines a YANG 1.1 module called "ietf-crypto-types". A high-level overview of the module is provided in . Examples illustrating the module's use are provided in Examples. The YANG module itself is defined in .

Data Model Overview This section provides an overview of the "ietf-crypto-types" module in terms of its features, identities, typedefs, and groupings.

Features The following diagram lists all the "feature" statements defined in the "ietf-crypto-types" module:

Identities The following diagram illustrates the relationship amongst the "identity" statements defined in the "ietf-crypto-types" module: Comments:

• The diagram shows that there are four base identities. The first three identities are used to indicate the format that key data, while the fourth identity is used to indicate the format for encrypted values. The base identities are "abstract", in the object oriented programming sense, in that they only define a "class" of formats, rather than a specific format.
• The various "leaf" identities define specific encoding formats. The derived identities defined in this document are sufficient for the effort described in but, by nature of them being identities, additional derived identities MAY be defined by future efforts.
• Identities used to specify uncommon formats are enabled by "feature" statements, allowing applications to support them when needed.

Typedefs The following diagram illustrates the relationship amongst the "typedef" statements defined in the "ietf-crypto-types" module: Comments:

• All the typedefs defined in the "ietf-crypto-types" module extend the "binary" type defined in .
• Additionally, all the typedefs define a type for encoding an ASN.1 structure using DER .
• The "trust-anchor-*" and "end-entity-*" typedefs are syntactically identical to their base typedefs and only distinguish themselves by the expected nature of their content. These typedefs are defined to facilitate common modeling needs.

Groupings The "ietf-crypto-types" module defines the following "grouping" statements:

• encrypted-value-grouping
• password-grouping
• symmetric-key-grouping
• public-key-grouping
• asymmetric-key-pair-grouping
• trust-anchor-cert-grouping
• end-entity-cert-grouping
• generate-csr-grouping
• asymmetric-key-pair-with-cert-grouping
• asymmetric-key-pair-with-certs-grouping

Each of these groupings are presented in the following subsections.

The "encrypted-value-grouping" Grouping The following tree diagram illustrates the "encrypted-value-grouping" grouping: Comments:

• The "encrypted-by" node is an empty container (difficult to see in the diagram) that a consuming module MUST augment key references into. The "ietf-crypto-types" module is unable to populate this container as the module only defines groupings. presents an example illustrating a consuming module populating the "encrypted-by" container.
• The "encrypted-value" node is the value, encrypted by the key referenced by the "encrypted-by" node, and encoded in the format appropriate for the kind of key it was encrypted by.
  • If the value is encrypted by a symmetric key, then the encrypted value is encoded using the format associated with the "symmetrically-encrypted-value-format" identity.
  • If the value is encrypted by an asymmetric key, then the encrypted value is encoded using the format associated with the "asymmetrically-encrypted-value-format" identity.
  See for information about the "format" identities.

The "password-grouping" Grouping This section presents two tree diagrams illustrating the "password-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• For the referenced grouping statement(s):
  • The "encrypted-value-grouping" grouping is discussed in .
• The "choice" statement enables the password data to be cleartext or encrypted, as follows:
  • The "cleartext-password" node can encode any cleartext value.
  • The "encrypted-password" node's structure is discussed in .

The "symmetric-key-grouping" Grouping This section presents two tree diagrams illustrating the "symmetric-key-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• For the referenced grouping statement(s):
  • The "encrypted-value-grouping" grouping is discussed in .
• The "key-format" node is an identity-reference to the "symmetric-key-format" abstract base identity discussed in , enabling the symmetric key to be encoded using the format defined by any of the derived identities.
• The "choice" statement enables the private key data to be cleartext, encrypted, or hidden, as follows:
  • The "cleartext-key" node can encode any cleartext key value.
  • The "hidden-key" node is of type "empty" as the real value cannot be presented via the management interface.
  • The "encrypted-key" node's structure is discussed in .

The "public-key-grouping" Grouping The following tree diagram illustrates the "public-key-grouping" grouping: Comments:

• The "public-key-format" node is an identity-reference to the "public-key-format" abstract base identity discussed in , enabling the public key to be encoded using the format defined by any of the derived identities.
• The "public-key" node is the public key data in the selected format. No "choice" statement is used to hide or encrypt the public key data because it is unnecessary to do so for public keys.

The "asymmetric-key-pair-grouping" Grouping This section presents two tree diagrams illustrating the "asymmetric-key-pair-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• For the referenced grouping statement(s):
  • The "public-key-grouping" grouping is discussed in .
  • The "encrypted-value-grouping" grouping is discussed in .
• The "private-key-format" node is an identity-reference to the "private-key-format" abstract base identity discussed in , enabling the private key to be encoded using the format defined by any of the derived identities.
• The "choice" statement enables the private key data to be cleartext, encrypted, or hidden, as follows:
  • The "cleartext-private-key" node can encode any cleartext key value.
  • The "hidden-private-key" node is of type "empty" as the real value cannot be presented via the management interface.
  • The "encrypted-private-key" node's structure is discussed in .

The "certificate-expiration-grouping" Grouping The following tree diagram illustrates the "certificate-expiration-grouping" grouping: Comments:

• This grouping's only purpose is to define the "certificate-expiration" notification statement, used by the groupings defined in and .
• The "certificate-expiration" notification enables servers to notify clients when certificates are nearing expiration.
• The "expiration-date" node indicates when the designated certificate will (or did) expire.
• Identification of the certificate that is expiring is built into the notification itself. For an example, please see .

The "trust-anchor-cert-grouping" Grouping This section presents two tree diagrams illustrating the "trust-anchor-cert-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• For the referenced grouping statement(s):
  • The "certificate-expiration-grouping" grouping is discussed in .
• The "cert-data" node contains a chain of one or more certificates encoded using a "signed-data-cms" typedef discussed in .

The "end-entity-cert-grouping" Grouping This section presents two tree diagrams illustrating the "end-entity-cert-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• For the referenced grouping statement(s):
  • The "certificate-expiration-grouping" grouping is discussed in .
• The "cert-data" node contains a chain of one or more certificates encoded using a "signed-data-cms" typedef discussed in .

The "generate-csr-grouping" Grouping The following tree diagram illustrates the "generate-csr-grouping" grouping: Comments:

• This grouping's only purpose is to define the "generate-certificate-signing-request" action statement, used by the groupings defined in and .
• This action takes as input a "csr-info" type and returns a "csr" type, both of which are discussed in .
• For an example, please see .

The "asymmetric-key-pair-with-cert-grouping" Grouping This section presents two tree diagrams illustrating the "asymmetric-key-pair-with-cert-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• This grouping defines an asymmetric key with at most one associated certificate, a commonly needed combination in protocol models.
• For the referenced grouping statement(s):
  • The "asymmetric-key-pair-grouping" grouping is discussed in .
  • The "end-entity-cert-grouping" grouping is discussed in .
  • The "generate-csr-grouping" grouping is discussed in .

The "asymmetric-key-pair-with-certs-grouping" Grouping This section presents two tree diagrams illustrating the "asymmetric-key-pair-with-certs-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Comments:

• This grouping defines an asymmetric key with one or more associated certificates, a commonly needed combination in configuration models.
• For the referenced grouping statement(s):
  • The "asymmetric-key-pair-grouping" grouping is discussed in .
  • The "end-entity-cert-grouping" grouping is discussed in .
  • The "generate-csr-grouping" grouping is discussed in .

Protocol-accessible Nodes The "ietf-crypto-types" module does not contain any protocol-accessible nodes, but the module needs to be "implemented", as described in , in order for the identities in to be defined.

Example Usage

The "symmetric-key-grouping" and "asymmetric-key-pair-with-certs-grouping" Grouping The following non-normative module is constructed in order to illustrate the use of the "symmetric-key-grouping" (), the "asymmetric-key-pair-with-certs-grouping" (), and the "password-grouping" () grouping statements. Notably, this example illustrates a hidden asymmetric key (ex-hidden-asymmetric-key) has been used to encrypt a symmetric key (ex-encrypted-one-symmetric-based-symmetric-key) that has been used to encrypt another asymmetric key (ex-encrypted-rsa-based-asymmetric-key). Additionally, the symmetric key is also used to encrypt a password (ex-encrypted-password). "; description "This module illustrates the 'symmetric-key-grouping' and 'asymmetric-key-grouping' groupings defined in the 'ietf-crypto-types' module defined in RFC AAAA."; revision 2022-07-07 { description "Initial version"; reference "RFC AAAA: Common YANG Data Types for Cryptography"; } container symmetric-keys { description "A container of symmetric keys."; list symmetric-key { key "name"; description "A symmetric key"; leaf name { type string; description "An arbitrary name for this key."; } uses ct:symmetric-key-grouping { augment "key-type/encrypted-key/encrypted-key/" + "encrypted-by" { description "Augments in a choice statement enabling the encrypting key to be any other symmetric or asymmetric key."; uses encrypted-by-choice-grouping; } } } } container asymmetric-keys { description "A container of asymmetric keys."; list asymmetric-key { key "name"; leaf name { type string; description "An arbitrary name for this key."; } uses ct:asymmetric-key-pair-with-certs-grouping { augment "private-key-type/encrypted-private-key/" + "encrypted-private-key/encrypted-by" { description "Augments in a choice statement enabling the encrypting key to be any other symmetric or asymmetric key."; uses encrypted-by-choice-grouping; } } description "An asymmetric key pair with associated certificates."; } } container passwords { description "A container of passwords."; list password { key "name"; leaf name { type string; description "An arbitrary name for this password."; } uses ct:password-grouping { augment "password-type/encrypted-password/" + "encrypted-password/encrypted-by" { description "Augments in a choice statement enabling the encrypting key to be any symmetric or asymmetric key."; uses encrypted-by-choice-grouping; } } description "A password."; } } grouping encrypted-by-choice-grouping { description "A grouping that defines a choice enabling references to other keys."; choice encrypted-by-choice { mandatory true; description "A choice amongst other symmetric or asymmetric keys."; case symmetric-key-ref { leaf symmetric-key-ref { type leafref { path "/ectu:symmetric-keys/ectu:symmetric-key/" + "ectu:name"; } description "Identifies the symmetric key that encrypts this key."; } } case asymmetric-key-ref { leaf asymmetric-key-ref { type leafref { path "/ectu:asymmetric-keys/ectu:asymmetric-key/" + "ectu:name"; } description "Identifies the asymmetric key that encrypts this key."; } } } } } ]]> The tree diagram for this example module follows: Finally, the following example illustrates various symmetric and asymmetric keys as they might appear in configuration: ex-hidden-symmetric-key ex-octet-string-based-symmetric-key ct:octet-string-key-format BASE64VALUE= ex-one-symmetric-based-symmetric-key ct:one-symmetric-key-format BASE64VALUE= ex-encrypted-one-symmetric-based-symmetric-key ct:one-symmetric-key-format ex-hidden-asymmetric-key ct:cms-enveloped-data-format BASE64VALUE= ex-hidden-asymmetric-key ct:subject-public-key-info-format BASE64VALUE= ex-hidden-asymmetric-key-cert BASE64VALUE= ex-rsa-based-asymmetric-key ct:subject-public-key-info-format BASE64VALUE= ct:rsa-private-key-format BASE64VALUE= ex-cert BASE64VALUE= ex-one-asymmetric-based-asymmetric-key ct:subject-public-key-info-format BASE64VALUE= ct:one-asymmetric-key-format BASE64VALUE= ex-encrypted-rsa-based-asymmetric-key ct:subject-public-key-info-format BASE64VALUE= ct:rsa-private-key-format ex-encrypted-one-symmetric-based-symmetri\ c-key ct:cms-encrypted-data-format BASE64VALUE= ex-cleartext-password super-secret ex-encrypted-password ex-encrypted-one-symmetric-based-symmetri\ c-key ct:cms-encrypted-data-format BASE64VALUE= ]]>

The "generate-certificate-signing-request" Action The following example illustrates the "generate-certificate-signing-request" action, discussed in , with the NETCONF protocol. REQUEST ex-hidden-asymmetric-key ct:p10-csr BASE64VALUE= ]]> RESPONSE \ BASE64VALUE= ]]>

The "certificate-expiration" Notification The following example illustrates the "certificate-expiration" notification, discussed in , with the NETCONF protocol. 2018-05-25T00:01:00Z ex-hidden-asymmetric-key ex-hidden-asymmetric-key-cert 2018-08-05T14:18:53-05:00 ]]>

YANG Module This module has normative references to , , , , , , , , , , , , , , and . <CODE BEGINS> file "ietf-crypto-types@2022-07-07.yang" Author: Kent Watsen "; description "This module defines common YANG types for cryptographic applications. Copyright (c) 2022 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 Revised 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 AAAA (https://www.rfc-editor.org/info/rfcAAAA); 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 2022-07-07 { description "Initial version"; reference "RFC AAAA: YANG Data Types and Groupings for Cryptography"; } /****************/ /* Features */ /****************/ feature one-symmetric-key-format { description "Indicates that the server supports the 'one-symmetric-key-format' identity."; } feature one-asymmetric-key-format { description "Indicates that the server supports the 'one-asymmetric-key-format' identity."; } feature symmetrically-encrypted-value-format { description "Indicates that the server supports the 'symmetrically-encrypted-value-format' identity."; } feature asymmetrically-encrypted-value-format { description "Indicates that the server supports the 'asymmetrically-encrypted-value-format' identity."; } feature cms-enveloped-data-format { description "Indicates that the server supports the 'cms-enveloped-data-format' identity."; } feature cms-encrypted-data-format { description "Indicates that the server supports the 'cms-encrypted-data-format' identity."; } feature csr-generation { description "Indicates that the server implements the 'generate-csr' action."; } feature p10-based-csrs { description "Indicates that the erver implements support for generating P10-based CSRs, as defined in RFC 2986."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7"; } feature certificate-expiration-notification { description "Indicates that the server implements the 'certificate-expiration' notification."; } feature hidden-keys { description "Indicates that the server supports hidden keys."; } feature password-encryption { description "Indicates that the server supports password encryption."; } feature symmetric-key-encryption { description "Indicates that the server supports encryption of symmetric keys."; } feature private-key-encryption { description "Indicates that the server supports encryption of private keys."; } /*************************************************/ /* Base Identities for Key Format Structures */ /*************************************************/ identity symmetric-key-format { description "Base key-format identity for symmetric keys."; } identity public-key-format { description "Base key-format identity for public keys."; } identity private-key-format { description "Base key-format identity for private keys."; } /****************************************************/ /* Identities for Private Key Format Structures */ /****************************************************/ identity rsa-private-key-format { base private-key-format; description "Indicates that the private key value is encoded as an RSAPrivateKey (from RFC 3447)."; reference "RFC 3447: PKCS #1: RSA Cryptography Specifications Version 2.2"; } identity ec-private-key-format { base private-key-format; description "Indicates that the private key value is encoded as an ECPrivateKey (from RFC 5915)"; reference "RFC 5915: Elliptic Curve Private Key Structure"; } identity one-asymmetric-key-format { if-feature "one-asymmetric-key-format"; base private-key-format; description "Indicates that the private key value is a CMS OneAsymmetricKey structure, as defined in RFC 5958, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5958: Asymmetric Key Packages 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)."; } /***************************************************/ /* Identities for Public Key Format Structures */ /***************************************************/ identity ssh-public-key-format { base public-key-format; description "Indicates that the public key value is an SSH public key, as specified by RFC 4253, Section 6.6, i.e.: string certificate or public key format identifier byte[n] key/certificate data."; reference "RFC 4253: The Secure Shell (SSH) Transport Layer Protocol"; } identity subject-public-key-info-format { base public-key-format; description "Indicates that the public key value is a SubjectPublicKeyInfo structure, as described in RFC 5280 encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile 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)."; } /******************************************************/ /* Identities for Symmetric Key Format Structures */ /******************************************************/ identity octet-string-key-format { base symmetric-key-format; description "Indicates that the key is encoded as a raw octet string. The length of the octet string MUST be appropriate for the associated algorithm's block size. How the associated algorithm is known is outside the scope of this module. This statement also applies when the octet string has been encrypted."; } identity one-symmetric-key-format { if-feature "one-symmetric-key-format"; base symmetric-key-format; description "Indicates that the private key value is a CMS OneSymmetricKey structure, as defined in RFC 6031, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 6031: Cryptographic Message Syntax (CMS) Symmetric Key Package Content Type 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)."; } /*************************************************/ /* Identities for Encrypted Value Structures */ /*************************************************/ identity encrypted-value-format { description "Base format identity for encrypted values."; } identity symmetrically-encrypted-value-format { if-feature "symmetrically-encrypted-value-format"; base encrypted-value-format; description "Base format identity for symmetrically encrypted values."; } identity asymmetrically-encrypted-value-format { if-feature "asymmetrically-encrypted-value-format"; base encrypted-value-format; description "Base format identity for asymmetrically encrypted values."; } identity cms-encrypted-data-format { if-feature "cms-encrypted-data-format"; base symmetrically-encrypted-value-format; description "Indicates that the encrypted value conforms to the 'encrypted-data-cms' type with the constraint that the 'unprotectedAttrs' value is not set."; reference "RFC 5652: Cryptographic Message Syntax (CMS) 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)."; } identity cms-enveloped-data-format { if-feature "cms-enveloped-data-format"; base asymmetrically-encrypted-value-format; description "Indicates that the encrypted value conforms to the 'enveloped-data-cms' type with the following constraints: The EnvelopedData structure MUST have exactly one 'RecipientInfo'. If the asymmetric key supports public key cryptography (e.g., RSA), then the 'RecipientInfo' must be a 'KeyTransRecipientInfo' with the 'RecipientIdentifier' using a 'subjectKeyIdentifier' with the value set using 'method 1' in RFC 7093 over the recipient's public key. Otherwise, if the asymmetric key supports key agreement (e.g., ECC), then the 'RecipientInfo' must be a 'KeyAgreeRecipientInfo'. The 'OriginatorIdentifierOrKey' value must use the 'OriginatorPublicKey' alternative. The 'UserKeyingMaterial' value must not be present. There must be exactly one 'RecipientEncryptedKeys' value having the 'KeyAgreeRecipientIdentifier' set to 'rKeyId' with the value set using 'method 1' in RFC 7093 over the recipient's public key."; reference "RFC 5652: Cryptographic Message Syntax (CMS) RFC 7093: Additional Methods for Generating Key Identifiers Values 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)."; } /*********************************************************/ /* Identities for Certificate Signing Request Formats */ /*********************************************************/ identity csr-format { description "A base identity for the certificate signing request formats. Additional derived identities MAY be defined by future efforts."; } identity p10-csr { if-feature "p10-based-csrs"; base csr-format; description "Indicates the 'CertificationRequest' structure defined in RFC 2986."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7"; } /***************************************************/ /* Typedefs for ASN.1 structures from RFC 2986 */ /***************************************************/ typedef csr-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."; 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)."; } typedef p10-csr { type binary; description "A CertificationRequest structure, as specified 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)."; } /***************************************************/ /* Typedefs for ASN.1 structures from RFC 5280 */ /***************************************************/ typedef x509 { type binary; description "A Certificate structure, as specified in RFC 5280, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile 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)."; } typedef crl { type binary; description "A CertificateList structure, as specified in RFC 5280, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile 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)."; } /***************************************************/ /* Typedefs for ASN.1 structures from RFC 6960 */ /***************************************************/ typedef oscp-request { type binary; description "A OCSPRequest structure, as specified in RFC 6960, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 6960: X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP 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)."; } typedef oscp-response { type binary; description "A OCSPResponse structure, as specified in RFC 6960, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 6960: X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP 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)."; } /***********************************************/ /* Typedefs for ASN.1 structures from 5652 */ /***********************************************/ typedef cms { type binary; description "A ContentInfo structure, as specified in RFC 5652, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5652: Cryptographic Message Syntax (CMS) 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)."; } typedef data-content-cms { type cms; description "A CMS structure whose top-most content type MUST be the data content type, as described by Section 4 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef signed-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the signed-data content type, as described by Section 5 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef enveloped-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the enveloped-data content type, as described by Section 6 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef digested-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the digested-data content type, as described by Section 7 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef encrypted-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the encrypted-data content type, as described by Section 8 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef authenticated-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the authenticated-data content type, as described by Section 9 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } /*********************************************************/ /* Typedefs for ASN.1 structures related to RFC 5280 */ /*********************************************************/ typedef trust-anchor-cert-x509 { type x509; description "A Certificate structure that MUST encode a self-signed root certificate."; } typedef end-entity-cert-x509 { type x509; description "A Certificate structure that MUST encode a certificate that is neither self-signed nor having Basic constraint CA true."; } /*********************************************************/ /* Typedefs for ASN.1 structures related to RFC 5652 */ /*********************************************************/ typedef trust-anchor-cert-cms { type signed-data-cms; description "A CMS SignedData structure that MUST contain the chain of X.509 certificates needed to authenticate the certificate presented by a client or end-entity. The CMS MUST contain only a single chain of certificates. The client or end-entity certificate MUST only authenticate to last intermediate CA certificate listed in the chain. In all cases, the chain MUST include a self-signed root certificate. In the case where the root certificate is itself the issuer of the client or end-entity certificate, only one certificate is present. This CMS structure MAY (as applicable where this type is used) also contain suitably fresh (as defined by local policy) revocation objects with which the device can verify the revocation status of the certificates. This CMS encodes the degenerate form of the SignedData structure that is commonly used to disseminate X.509 certificates and revocation objects (RFC 5280)."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile."; } typedef end-entity-cert-cms { type signed-data-cms; description "A CMS SignedData structure that MUST contain the end entity certificate itself, and MAY contain any number of intermediate certificates leading up to a trust anchor certificate. The trust anchor certificate MAY be included as well. The CMS MUST contain a single end entity certificate. The CMS MUST NOT contain any spurious certificates. This CMS structure MAY (as applicable where this type is used) also contain suitably fresh (as defined by local policy) revocation objects with which the device can verify the revocation status of the certificates. This CMS encodes the degenerate form of the SignedData structure that is commonly used to disseminate X.509 certificates and revocation objects (RFC 5280)."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile."; } /*****************/ /* Groupings */ /*****************/ grouping encrypted-value-grouping { description "A reusable grouping for a value that has been encrypted by a referenced symmetric or asymmetric key."; container encrypted-by { nacm:default-deny-write; description "An empty container enabling a reference to the key that encrypted the value to be augmented in. The referenced key MUST be a symmetric key or an asymmetric key. A symmetric key MUST be referenced via a leaf node called 'symmetric-key-ref'. An asymmetric key MUST be referenced via a leaf node called 'asymmetric-key-ref'. The leaf nodes MUST be direct descendants in the data tree, and MAY be direct descendants in the schema tree."; } leaf encrypted-value-format { type identityref { base encrypted-value-format; } mandatory true; description "Identifies the format of the 'encrypted-value' leaf. If 'encrypted-by' points to a symmetric key, then a 'symmetrically-encrypted-value-format' based identity MUST by set (e.g., cms-encrypted-data-format). If 'encrypted-by' points to an asymmetric key, then an 'asymmetrically-encrypted-value-format' based identity MUST by set (e.g., cms-enveloped-data-format)."; } leaf encrypted-value { nacm:default-deny-write; type binary; must '../encrypted-by'; mandatory true; description "The value, encrypted using the referenced symmetric or asymmetric key. The value MUST be encoded using the format associated with the 'encrypted-value-format' leaf."; } } grouping password-grouping { description "A password that MAY be encrypted."; choice password-type { nacm:default-deny-write; mandatory true; description "Choice between password types."; case cleartext-password { leaf cleartext-password { nacm:default-deny-all; type string; description "The cleartext value of the password."; } } case encrypted-password { if-feature "password-encryption"; container encrypted-password { description "A container for the encrypted password value."; uses encrypted-value-grouping; } } } } grouping symmetric-key-grouping { description "A symmetric key."; leaf key-format { nacm:default-deny-write; type identityref { base symmetric-key-format; } description "Identifies the symmetric key's format. Implementations SHOULD ensure that the incoming symmetric key value is encoded in the specified format. For encrypted keys, the value is the same as it would have been if the key were not encrypted."; } choice key-type { nacm:default-deny-write; mandatory true; description "Choice between key types."; case cleartext-key { leaf cleartext-key { nacm:default-deny-all; type binary; must '../key-format'; description "The binary value of the key. The interpretation of the value is defined by the 'key-format' field."; } } case hidden-key { if-feature "hidden-keys"; leaf hidden-key { type empty; must 'not(../key-format)'; description "A hidden key. How such keys are created is outside the scope of this module."; } } case encrypted-key { if-feature "symmetric-key-encryption"; container encrypted-key { must '../key-format'; description "A container for the encrypted symmetric key value. The interpretation of the 'encrypted-value' node is via the 'key-format' node"; uses encrypted-value-grouping; } } } } grouping public-key-grouping { description "A public key."; leaf public-key-format { nacm:default-deny-write; type identityref { base public-key-format; } mandatory true; description "Identifies the public key's format. Implementations SHOULD ensure that the incoming public key value is encoded in the specified format."; } leaf public-key { nacm:default-deny-write; type binary; mandatory true; description "The binary value of the public key. The interpretation of the value is defined by 'public-key-format' field."; } } grouping asymmetric-key-pair-grouping { description "A private key and its associated public key. Implementations SHOULD ensure that the two keys are a matching pair."; uses public-key-grouping; leaf private-key-format { nacm:default-deny-write; type identityref { base private-key-format; } description "Identifies the private key's format. Implementations SHOULD ensure that the incoming private key value is encoded in the specified format. For encrypted keys, the value is the same as it would have been if the key were not encrypted."; } choice private-key-type { nacm:default-deny-write; mandatory true; description "Choice between key types."; case cleartext-private-key { leaf cleartext-private-key { nacm:default-deny-all; type binary; must '../private-key-format'; description "The value of the binary key The key's value is interpreted by the 'private-key-format' field."; } } case hidden-private-key { if-feature "hidden-keys"; leaf hidden-private-key { type empty; must 'not(../private-key-format)'; description "A hidden key. How such keys are created is outside the scope of this module."; } } case encrypted-private-key { if-feature "private-key-encryption"; container encrypted-private-key { must '../private-key-format'; description "A container for the encrypted asymmetric private key value. The interpretation of the 'encrypted-value' node is via the 'private-key-format' node"; uses encrypted-value-grouping; } } } } grouping certificate-expiration-grouping { description "A notification for when a certificate is about to, or already has, expired."; notification certificate-expiration { if-feature "certificate-expiration-notification"; description "A notification indicating that the configured certificate is either about to expire or has already expired. When to send notifications is an implementation specific decision, but it is RECOMMENDED that a notification be sent once a month for 3 months, then once a week for four weeks, and then once a day thereafter until the issue is resolved."; leaf expiration-date { type yang:date-and-time; mandatory true; description "Identifies the expiration date on the certificate."; } } } grouping trust-anchor-cert-grouping { description "A trust anchor certificate, and a notification for when it is about to (or already has) expire."; leaf cert-data { nacm:default-deny-write; type trust-anchor-cert-cms; description "The binary certificate data for this certificate."; } uses certificate-expiration-grouping; } grouping end-entity-cert-grouping { description "An end entity certificate, and a notification for when it is about to (or already has) expire. Implementations SHOULD assert that, where used, the end entity certificate contains the expected public key."; leaf cert-data { nacm:default-deny-write; type end-entity-cert-cms; description "The binary certificate data for this certificate."; } uses certificate-expiration-grouping; } grouping generate-csr-grouping { description "Defines the 'generate-csr' action."; action generate-csr { if-feature "csr-generation"; nacm:default-deny-all; description "Generates a certificate signing request structure for the associated asymmetric key using the passed subject and attribute values. This action statement is only available when the associated 'public-key-format' node's value is 'subject-public-key-info-format'."; reference "RFC 6125: Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS)"; input { leaf csr-format { type identityref { base csr-format; } mandatory true; description "Specifies the format for the returned certifiacte."; } leaf csr-info { type csr-info; mandatory true; description "A CertificationRequestInfo structure, as defined in RFC 2986. Enables the client to provide a fully-populated CertificationRequestInfo structure that the server only needs to sign in order to generate the complete 'CertificationRequest' structure to return in the 'output'. The 'AlgorithmIdentifier' field contained inside the 'SubjectPublicKeyInfo' field MUST be one known to be supported by the device."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification RFC AAAA: YANG Data Types and Groupings for Cryptography"; } } output { choice csr-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-csr { leaf p10-csr { type p10-csr; description "A CertificationRequest, as defined in RFC 2986."; } description "A CertificationRequest, as defined in RFC 2986."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification RFC AAAA: YANG Data Types and Groupings for Cryptography"; } } } } } // generate-csr-grouping grouping asymmetric-key-pair-with-cert-grouping { description "A private/public key pair and an associated certificate. Implementations SHOULD assert that certificates contain the matching public key."; uses asymmetric-key-pair-grouping; uses end-entity-cert-grouping; uses generate-csr-grouping; } // asymmetric-key-pair-with-cert-grouping grouping asymmetric-key-pair-with-certs-grouping { description "A private/public key pair and associated certificates. Implementations SHOULD assert that certificates contain the matching public key."; uses asymmetric-key-pair-grouping; container certificates { nacm:default-deny-write; description "Certificates associated with this asymmetric key."; list certificate { key "name"; description "A certificate for this asymmetric key."; leaf name { type string; description "An arbitrary name for the certificate."; } uses end-entity-cert-grouping { refine "cert-data" { mandatory true; } } } } uses generate-csr-grouping; } // asymmetric-key-pair-with-certs-grouping } ]]> <CODE ENDS>

Security Considerations

No Support for CRMF This document uses PKCS #10 for the "generate-certificate-signing-request" action. The use of Certificate Request Message Format (CRMF) was considered, but it was unclear if there was market demand for it. If it is desired to support CRMF in the future, a backwards compatible solution can be defined at that time.

No Support for Key Generation Early revisions of this document included "rpc" statements for generating symmetric and asymmetric keys. These statements were removed due to an inability to obtain consensus for how to identify the key-algorithm to use. Thusly, the solution presented in this document only supports keys to be configured via an external client, which does not support Security best practice.

Unconstrained Public Key Usage This module defines the "public-key-grouping" grouping, which enables the configuration of public keys without constraints on their usage, e.g., what operations the key is allowed to be used for (encryption, verification, both). The "asymmetric-key-pair-grouping" grouping uses the aforementioned "public-key-grouping" grouping, and carries the same traits. The "asymmetric-key-pair-with-cert-grouping" grouping uses the aforementioned "asymmetric-key-pair-grouping" grouping, whereby each certificate may constrain the usage of the public key according to local policy.

Unconstrained Private Key Usage This module defines the "asymmetric-key-pair-grouping" grouping, which enables the configuration of private keys without constraints on their usage, e.g., what operations the key is allowed to be used for (e.g., signature, decryption, both). The "asymmetric-key-pair-with-cert-grouping" uses the aforementioned "asymmetric-key-pair-grouping" grouping, whereby configured certificates (e.g., identity certificates) may constrain the use of the public key according to local policy.

Strength of Keys Conveyed When accessing key values, it is desireable that implementations ensure that the strength of the keys being accessed is not greater than the strength of the underlying secure transport connection over which the keys are conveyed. However, comparing key strengths can be complicated and difficult to implement in practice. That said, expert Security opinion suggests that already it is infeasible to break a 128-bit symmetric key using a classical computer, and thus the concern for conveying higher-strength keys begins to lose its allure. Implementations SHOULD only use secure transport protocols meeting local policy. A reasonable policy may, e.g., state that only ciphersuites listed as "recommended" by the IETF be used (e.g., for TLS).

Encrypting Passwords The module contained within this document enables passwords to be encrypted. Passwords may be encrypted via a symmetric key using the "cms-encrypted-data-format" format. This format uses the CMS EncryptedData structure, which allows any encryption algorithm to be used. In order to thwart rainbow attacks, algorithms that result in a unique output for the same input SHOULD NOT be used. For instance, AES using "ECB" SHOULD NOT be used to encrypt passwords, whereas "CBC" mode is permissible since an unpredictable initialization vector (IV) MUST be used for each use.

Deletion of Cleartext Key Values This module defines storage for cleartext key values that SHOULD be zeroized when deleted, so as to prevent the remnants of their persisted storage locations from being analyzed in any meaningful way. The cleartext key values are the "cleartext-key" node defined in the "symmetric-key-grouping" grouping () and the "cleartext-private-key" node defined in the "asymmetric-key-pair-grouping" grouping (").

The "ietf-crypto-types" YANG Module The YANG module in this document defines "grouping" statements that are designed to be accessed via YANG based management protocols, such as NETCONF and RESTCONF . Both of these protocols have mandatory-to-implement secure transport layers (e.g., SSH, TLS) with mutual authentication. The NETCONF access control model (NACM) provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content. Since the module in this document only defines groupings, these considerations are primarily for the designers of other modules that use these groupings. Some of the readable data nodes defined in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:

• The "cleartext-key" node:
  • The "cleartext-key" node defined in the "symmetric-key-grouping" grouping is additionally sensitive to read operations such that, in normal use cases, it should never be returned to a client. For this reason, the NACM extension "default-deny-all" has been applied to it.
• The "cleartext-private-key" node:
  • The "cleartext-private-key" node defined in the "asymmetric-key-pair-grouping" grouping is additionally sensitive to read operations such that, in normal use cases, it should never be returned to a client. For this reason, the NACM extension "default-deny-all" has been applied.
• The "cert-data" node:
  • The "cert-data" node, defined in both the "trust-anchor-cert-grouping" and "end-entity-cert-grouping" groupings, is additionally sensitive to read operations, as certificates sometimes convey personally identifying information (especially end-entity certificates). However, as it is commonly understood that certificates are "public", the NACM extension "nacm:default-deny-write" (not "default-deny-all") has been applied. It is RECOMMENDED that implementations adjust read-access to certificates to comply with local policy.

All the writable data nodes defined by all the groupings defined in this module may be considered sensitive or vulnerable in some network environments. For instance, even the modification of a public key or a certificate can dramatically alter the implemented security policy. For this reason, the NACM extension "default-deny-write" has been applied to all the data nodes defined in the module. Some of the operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability:

• generate-certificate-signing-request:
  • This "action" statement SHOULD only be executed by authorized users. For this reason, the NACM extension "default-deny-all" has been applied. Note that NACM uses "default-deny-all" to protect "RPC" and "action" statements; it does not define, e.g., an extension called "default-deny-execute".
  • For this action, it is RECOMMENDED that implementations assert channel binding , so as to ensure that the application layer that sent the request is the same as the device authenticated when the secure transport layer was established.

IANA Considerations

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

References Normative References 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 #1 v2.1 from RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, and change control is retained within the PKCS process. The body of this document is taken directly from the PKCS #1 v2.1 document, with certain corrections made during the publication process. This memo provides information for the Internet community. The Secure Shell (SSH) is a protocol for secure remote login and other secure network services over an insecure network. This document describes the SSH transport layer protocol, which typically runs on top of TCP/IP. The protocol can be used as a basis for a number of secure network services. It provides strong encryption, server authentication, and integrity protection. It may also provide compression. Key exchange method, public key algorithm, symmetric encryption algorithm, message authentication algorithm, and hash algorithm are all negotiated. This document also describes the Diffie-Hellman key exchange method and the minimal set of algorithms that are needed to implement the SSH transport layer protocol. [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 the Cryptographic Message Syntax (CMS). This syntax is used to digitally sign, digest, authenticate, or encrypt arbitrary message content. [STANDARDS-TRACK] This document defines the syntax for private-key information and a content type for it. Private-key information includes a private key for a specified public-key algorithm and a set of attributes. The Cryptographic Message Syntax (CMS), as defined in RFC 5652, can be used to digitally sign, digest, authenticate, or encrypt the asymmetric key format content type. This document obsoletes RFC 5208. [STANDARDS-TRACK] This document defines the symmetric key format content type. It is transport independent. The Cryptographic Message Syntax (CMS) can be used to digitally sign, digest, authenticate, or encrypt this content type. [STANDARDS-TRACK] This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021. 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. 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. The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model. This document obsoletes RFC 6536. International Telecommunication Union International Telecommunication Union Informative References 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. 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 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] The concept of channel binding allows applications to establish that the two end-points of a secure channel at one network layer are the same as at a higher layer by binding authentication at the higher layer to the channel at the lower layer. This allows applications to delegate session protection to lower layers, which has various performance benefits. This document discusses and formalizes the concept of channel binding to secure channels. [STANDARDS-TRACK] This document specifies the syntax and semantics for conveying Elliptic Curve (EC) private key information. The syntax and semantics defined herein are based on similar syntax and semantics defined by the Standards for Efficient Cryptography Group (SECG). This document is not an Internet Standards Track specification; it is published for informational purposes. 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] Many application technologies enable secure communication between two entities by means of Internet Public Key Infrastructure Using X.509 (PKIX) certificates in the context of Transport Layer Security (TLS). This document specifies procedures for representing and verifying the identity of application services in such interactions. [STANDARDS-TRACK] The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK] Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) are widely used to protect data exchanged over application protocols such as HTTP, SMTP, IMAP, POP, SIP, and XMPP. Over the last few years, several serious attacks on TLS have emerged, including attacks on its most commonly used cipher suites and their modes of operation. This document provides recommendations for improving the security of deployed services that use TLS and DTLS. The recommendations are applicable to the majority of use cases. This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF). 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. Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950.

Change Log

I-D to 00

• Removed groupings and notifications.
• Added typedefs for identityrefs.
• Added typedefs for other RFC 5280 structures.
• Added typedefs for other RFC 5652 structures.
• Added convenience typedefs for RFC 4253, RFC 5280, and RFC 5652.

00 to 01

• Moved groupings from the draft-ietf-netconf-keystore here.

01 to 02

• Removed unwanted "mandatory" and "must" statements.
• Added many new crypto algorithms (thanks Haiguang!)
• Clarified in asymmetric-key-pair-with-certs-grouping, in certificates/certificate/name/description, that if the name MUST NOT match the name of a certificate that exists independently in <operational>, enabling certs installed by the manufacturer (e.g., an IDevID).

02 to 03

• renamed base identity 'asymmetric-key-encryption-algorithm' to 'asymmetric-key-algorithm'.
• added new 'asymmetric-key-algorithm' identities for secp192r1, secp224r1, secp256r1, secp384r1, and secp521r1.
• removed 'mac-algorithm' identities for mac-aes-128-ccm, mac-aes-192-ccm, mac-aes-256-ccm, mac-aes-128-gcm, mac-aes-192-gcm, mac-aes-256-gcm, and mac-chacha20-poly1305.
• for all -cbc and -ctr identities, renamed base identity 'symmetric-key-encryption-algorithm' to 'encryption-algorithm'.
• for all -ccm and -gcm identities, renamed base identity 'symmetric-key-encryption-algorithm' to 'encryption-and-mac-algorithm' and renamed the identity to remove the "enc-" prefix.
• for all the 'signature-algorithm' based identities, renamed from 'rsa-*' to 'rsassa-*'.
• removed all of the "x509v3-" prefixed 'signature-algorithm' based identities.
• added 'key-exchange-algorithm' based identities for 'rsaes-oaep' and 'rsaes-pkcs1-v1_5'.
• renamed typedef 'symmetric-key-encryption-algorithm-ref' to 'symmetric-key-algorithm-ref'.
• renamed typedef 'asymmetric-key-encryption-algorithm-ref' to 'asymmetric-key-algorithm-ref'.
• added typedef 'encryption-and-mac-algorithm-ref'.
• Updated copyright date, boilerplate template, affiliation, and folding algorithm.

03 to 04

• ran YANG module through formatter.

04 to 05

• fixed broken symlink causing reformatted YANG module to not show.

05 to 06

• Added NACM annotations.
• Updated Security Considerations section.
• Added 'asymmetric-key-pair-with-cert-grouping' grouping.
• Removed text from 'permanently-hidden' enum regarding such keys not being backed up or restored.
• Updated the boilerplate text in module-level "description" statement to match copyeditor convention.
• Added an explanation to the 'public-key-grouping' and 'asymmetric-key-pair-grouping' statements as for why the nodes are not mandatory (e.g., because they may exist only in <operational>.
• Added 'must' expressions to the 'public-key-grouping' and 'asymmetric-key-pair-grouping' statements ensuring sibling nodes are either all exist or do not all exist.
• Added an explanation to the 'permanently-hidden' that the value cannot be configured directly by clients and servers MUST fail any attempt to do so.
• Added 'trust-anchor-certs-grouping' and 'end-entity-certs-grouping' (the plural form of existing groupings).
• Now states that keys created in <operational> by the *-hidden-key actions are bound to the lifetime of the parent 'config true' node, and that subsequent invocations of either action results in a failure.

06 to 07

• Added clarifications that implementations SHOULD assert that configured certificates contain the matching public key.
• Replaced the 'generate-hidden-key' and 'install-hidden-key' actions with special 'crypt-hash' -like input/output values.

07 to 08

• Removed the 'generate-key and 'hidden-key' features.
• Added grouping symmetric-key-grouping
• Modified 'asymmetric-key-pair-grouping' to have a 'choice' statement for the keystone module to augment into, as well as replacing the 'union' with leafs (having different NACM settings.

08 to 09

• Converting algorithm from identities to enumerations.

09 to 10

• All the below changes are to the algorithm enumerations defined in ietf-crypto-types.
• Add in support for key exchange over x.25519 and x.448 based on RFC 8418.
• Add in SHAKE-128, SHAKE-224, SHAKE-256, SHAKE-384 and SHAKE 512
• Revise/add in enum of signature algorithm for x25519 and x448
• Add in des3-cbc-sha1 for IPSec
• Add in sha1-des3-kd for IPSec
• Add in definit for rc4-hmac and rc4-hmac-exp. These two algorithms have been deprecated in RFC 8429. But some existing draft in i2nsf may still want to use them.
• Add x25519 and x448 curve for asymmetric algorithms
• Add signature algorithms ed25519, ed25519-cts, ed25519ph
• add signature algorithms ed448, ed448ph
• Add in rsa-sha2-256 and rsa-sha2-512 for SSH protocols (rfc8332)

10 to 11

• Added a "key-format" identity.
• Added symmetric keys to the example in .

11 to 12

• Removed all non-essential (to NC/RC) algorithm types.
• Moved remaining algorithm types each into its own module.
• Added a 'config false' "algorithms-supported" list to each of the algorithm-type modules.

12 to 13

• Added the four features: "[encrypted-]one-[a]symmetric-key-format", each protecting a 'key-format' identity of the same name.
• Added 'must' expressions asserting that the 'key-format' leaf exists whenever a non-hidden key is specified.
• Improved the 'description' statements and added 'reference' statements for the 'key-format' identities.
• Added a questionable forward reference to "encrypted-*" leafs in a couple 'when' expressions.
• Did NOT move "config false" alg-supported lists to SSH/TLS drafts.

13 to 14

• Resolved the "FIXME: forward ref" issue by modulating 'must', 'when', and 'mandatory' expressions.
• Moved the 'generatesymmetric-key' and 'generate-asymmetric-key' actions from ietf-keystore to ietf-crypto-types, now as RPCs.
• Cleaned up various description statements and removed lingering FIXMEs.
• Converted the "iana-<alg-type>-algs" YANG modules to IANA registries with instructions for how to generate modules from the registries, whenever they may be updated.

14 to 15

• Removed the IANA-maintained registries for symmetric, asymmetric, and hash algorithms.
• Removed the "generate-symmetric-key" and "generate-asymmetric-key" RPCs.
• Removed the "algorithm" node in the various symmetric and asymmetric key groupings.
• Added 'typedef csr' and 'feature certificate-signing-request-generation'.
• Refined a usage of "end-entity-cert-grouping" to make the "cert" node mandatory true.
• Added a "Note to Reviewers" note to first page.

15 to 16

• Updated draft title (refer to "Groupings" too).
• Removed 'end-entity-certs-grouping' as it wasn't being used anywhere.
• Removed 'trust-anchor-certs-grouping' as it was no longer being used after modifying 'local-or-truststore-certs-grouping' to use lists (not leaf-lists).
• Renamed "cert" to "cert-data" in trust-anchor-cert-grouping.
• Added "csr-info" typedef, to complement the existing "csr" typedef.
• Added "ocsp-request" and "ocsp-response" typedefs, to complement the existing "crl" typedef.
• Added "encrypted" cases to both symmetric-key-grouping and asymmetric-key-pair-grouping (Moved from Keystore draft).
• Expanded "Data Model Overview section(s) [remove "wall" of tree diagrams].
• Updated the Security Considerations section.

16 to 17

• [Re]-added a "Strength of Keys Configured" Security Consideration
• Prefixed "cleartext-" in the "key" and "private-key" node names.

17 to 18

• Fixed issues found by the SecDir review of the "keystore" draft.
• Added "password-grouping", discussed during the IETF 108 session.

18 to 19

• Added a "Unconstrained Public Key Usage" Security Consideration to address concern raised by SecDir of the 'truststore' draft.
• Added a "Unconstrained Private Key Usage" Security Consideration to address concern raised by SecDir of the 'truststore' draft.
• Changed the encryption strategy, after conferring with Russ Housley.
• Added a "password-grouping" example to the "crypto-types-usage" example.
• Added an "Encrypting Passwords" section to Security Consideration.
• Addressed other comments raised by YANG Doctor.

19 to 20

• Nits found via YANG Doctors reviews.
• Aligned modules with `pyang -f` formatting.

20 to 21

• Replaced "base64encodedvalue==" with "BASE64VALUE=".
• Accommodated SecDir review by Valery Smyslov.

21 to 22

• fixup the 'WG Web' and 'WG List' lines in YANG module(s)
• fixup copyright (i.e., s/Simplified/Revised/) in YANG module(s)
• added 'hidden-keys' feature.

22 to 23

• Fixed an example to reference correct key.
• Fixed an example to not have line-returns around the encoding for a binary value.

23 to 24

• Added mandatory leaf "csr-format" to action "generate-csr".
• s/certificate-signing-request/csr/g in the YANG module.

Acknowledgements The authors would like to thank for following for lively discussions on list and in the halls (ordered by first name): Balazs Kovacs, Eric Voit, Juergen Schoenwaelder, Liang Xia, Martin Bjoerklund, Nick Hancock, Rich Salz, Rob Wilton, Russ Housley, Sandra Murphy, Tom Petch, Valery Smyslov, and Wang Haiguang.