module ietf-tpm-remote-attestation {

    yang-version 1.1;

    namespace
      "urn:ietf:params:xml:ns:yang"
        + ":ietf-tpm-remote-attestation";

    prefix tpm;

    import ietf-yang-types {
      prefix yang;
    }
    import ietf-hardware {
      prefix hw;
    }
    import ietf-keystore {
      prefix ks;
    }
    import ietf-tcg-algs {
      prefix taa;
    }

    organization
      "IETF RATS (Remote ATtestation procedureS) Working Group";

    contact
      "WG Web  : <https://datatracker.ietf.org/wg/rats/>
     WG List : <mailto:rats@ietf.org>
     Author  : Eric Voit <evoit@cisco.com>
     Author  : Henk Birkholz <henk.birkholz@ietf.contact>
     Author  : Michael Eckel <michael.eckel@sit.fraunhofer.de>
     Author  : Shwetha Bhandari <shwetha.bhandari@thoughtspot.com>
     Author  : Bill Sulzen <bsulzen@cisco.com>
     Author  : Liang Xia (Frank) <frank.xialiang@huawei.com>
     Author  : Tom Laffey <tom.laffey@hpe.com>
     Author  : Guy C. Fedorkow <gfedorkow@juniper.net>";

    description
      "A YANG module to enable remote attestation procedures based
     on TPM 1.2 and TPM 2.0 using a challenge-response
     interaction model and the Quote primitive operations defined
     by TPM 1.2 and TPM 2.0.

     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.

     Copyright (c) 2024 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 9684; see the
     RFC itself for full legal notices.";

    revision "2024-12-05" {
      description "Initial version";
      reference
        "RFC 9684: A YANG Data Model for Challenge-Response-Based
        Remote Attestation (CHARRA) Procedures Using Trusted Platform
        Modules (TPMs)";

    }


    feature mtpm {
      description
        "The device supports the remote attestation of multiple
       TPM-based cryptoprocessors.";
    }

    feature bios {
      description
        "The device supports the BIOS logs.";
      reference
        "BIOS-Log:
        TCG PC Client Platform Firmware Profile Specification,
        https://trustedcomputinggroup.org/wp-content/uploads/
        TCG-PC-Client-Platform-Firmware-Profile-Version-1.06-
        Revision-52_pub-2.pdf, Section 10.4.5.2";

    }

    feature ima {
      description
        "The device supports Integrity Measurement Architecture logs.
       Many variants of IMA logs exist in the deployment.  Each
       encodes the log entry contents as the specific measurements
       that get hashed into a PCRs as Evidence.  See the reference
       below for one example of such an encoding.";
      reference
        "CEL:
        Canonical Event Log Format,
        https://www.trustedcomputinggroup.org/wp-content/uploads/
        TCG_IWG_CEL_v1_r0p41_pub.pdf, Section 5.1.6";

    }

    feature netequip_boot {
      description
        "The device supports the netequip_boot logs.";
      reference
        "RFC 9684: A YANG Data Model for Challenge-Response-Based
        Remote Attestation (CHARRA) Procedures Using Trusted Platform
        Modules (TPMs), Appendix B";

    }

    typedef pcr {
      type uint8 {
        range "0..31";
      }
      description
        "Valid index number for a PCR.  A PCR index compliant with
       TPM 2.0 extends from 0-31.  At this time, a typical TPM would
       have no more than 32 PCRs.";
    }

    typedef compute-node-ref {
      type leafref {
        path "/tpm:rats-support-structures/tpm:compute-nodes/tpm:compute-node/tpm:node-id";
      }
      description
        "This type is used to reference a hardware node.  Note that an
       implementer might include an alternative leafref pointing to a
       different YANG module node specifying hardware structures.";
    }

    typedef certificate-name-ref {
      type leafref {
        path "/tpm:rats-support-structures/tpm:tpms/tpm:tpm/tpm:certificates/tpm:certificate/tpm:name";
      }
      description
        "A type that allows identification of a TPM-based
       certificate.";
    }

    identity attested_event_log_type {
      description
        "Base identity allowing categorization of the reasons why an
       attested measurement has been taken on an Attester.";
    }

    identity ima {
      base attested_event_log_type;
      description
        "An event type recorded in IMA.";
    }

    identity bios {
      base attested_event_log_type;
      description
        "An event type associated with BIOS/UEFI.";
    }

    identity netequip_boot {
      base attested_event_log_type;
      description
        "An event type associated with Network Equipment Boot.";
    }

    grouping tpm20-hash-algo {
      description
        "The cryptographic algorithm used to hash the PCRs compliant
       with TPM 2.0.  This must be from the list of platform-
       supported options.";
      leaf tpm20-hash-algo {
        type identityref {
          base taa:hash;
        }
        must
          '. = /tpm:rats-support-structures'
            + '/tpm:attester-supported-algos/tpm:tpm20-hash' {
          error-message
            "This platform does not support "
              + "tpm20-hash-algo";
        }
        description
          "The hash scheme that is used to hash a PCR compliant with
         TPM 2.0.  This must be one of those supported by a platform.
         Where this object does not appear, the default value of
         'taa:TPM_ALG_SHA256' will apply.";
      }
    }  // grouping tpm20-hash-algo

    grouping tpm12-hash-algo {
      description
        "The cryptographic algorithm used to hash the PCRs compliant
       with TPM 1.2.";
      leaf tpm12-hash-algo {
        type identityref {
          base taa:hash;
        }
        must
          '. = /tpm:rats-support-structures'
            + '/tpm:attester-supported-algos/tpm:tpm12-hash' {
          error-message
            "This platform does not support "
              + "tpm12-hash-algo";
        }
        description
          "The hash scheme that is used to hash a PCR compliant with
         TPM 1.2.  This MUST be one of those supported by a platform.
         Where this object does not appear, the default value of
         'taa:TPM_ALG_SHA1' will apply.";
      }
    }  // grouping tpm12-hash-algo

    grouping nonce {
      description
        "A random number intended to guarantee freshness and for use
       as part of a replay-detection mechanism.";
      leaf nonce-value {
        type binary;
        mandatory true;
        description
          "A cryptographically generated random number that should
         not be predictable prior to its issuance from a random
         number generation function.  The random number MUST be
         derived from an entropy source external to the Attester.

         Note that a nonce sent into a TPM will typically be 160 or
         256 binary digits long.  (This is 20 or 32 bytes.)  So if
         fewer binary digits are sent, this nonce object will be
         padded with leading zeros within Quotes returned from the
         TPM.  Additionally, if more bytes are sent, the nonce will
         be trimmed to the most significant binary digits.";
      }
    }  // grouping nonce

    grouping tpm12-pcr-selection {
      description
        "A Verifier can request one or more PCR values using its
       individually created Attestation Key Certificate (AC).
       The corresponding selection filter is represented in this
       grouping.";
      leaf-list pcr-index {
        type pcr;
        description
          "The numbers/indexes of the PCRs.  In addition, any selection
         of PCRs MUST verify that the set of PCRs requested are a
         subset of the set of PCRs exposed in the leaf-list
         /tpm:rats-support-structures
         /tpm:tpms/tpm:tpm[name=current()]/tpm:tpm12-pcrs";
      }
    }  // grouping tpm12-pcr-selection

    grouping tpm20-pcr-selection {
      description
        "A Verifier can acquire one or more PCR values, which are
       hashed together in a TPM2B_DIGEST coming from the TPM2.
       The selection list of desired PCRs and the hash algorithm
       is represented in this grouping.";
      list tpm20-pcr-selection {
        unique "tpm20-hash-algo";
        description
          "Specifies the list of PCRs and hash algorithms that can be
         returned within a TPM2B_DIGEST.";
        reference
          "TPM2.0-Structures:
          Trusted Platform Module Library Part 2:  Structures,
          Revision 01.83, https://trustedcomputinggroup.org/
          wp-content/uploads/TPM-2.0-1.83-Part-2-Structures.pdf,
          Section 10.9.7";

        uses tpm20-hash-algo;

        leaf-list pcr-index {
          type pcr;
          description
            "The numbers of the PCRs that are being tracked
           with a hash based on the tpm20-hash-algo.  In addition,
           any selection of PCRs MUST verify that the set of PCRs
           requested are a subset of the set of selected PCR indexes
           available for that specific TPM.";
        }
      }  // list tpm20-pcr-selection
    }  // grouping tpm20-pcr-selection

    grouping certificate-name-ref {
      description
        "Identifies a certificate in a keystore.";
      leaf certificate-name {
        type certificate-name-ref;
        mandatory true;
        description
          "Identifies a certificate in a keystore.";
      }
    }  // grouping certificate-name-ref

    grouping tpm-name {
      description
        "A unique TPM on a device.";
      leaf name {
        type string;
        description
          "Unique system-generated name for a TPM on a device.";
      }
    }  // grouping tpm-name

    grouping node-uptime {
      description
        "Uptime in seconds of the node.";
      leaf up-time {
        type uint32;
        description
          "Uptime in seconds of this node reporting its data.";
      }
    }  // grouping node-uptime

    grouping tpm12-attestation {
      description
        "Contains an instance of cryptoprocessor measurements signed
       according to TPM 1.2.  It is supplemented by unsigned
       Attester information.";
      uses node-uptime;

      leaf pcr-data {
        type binary;
        description
          "The value created and signed for the quote
         (type TPM_PCR_INFO_SHORT), i.e., the 'pcrData' part of
          a TPM1.2 Quote2 operation result.";
        reference
          "TPM1.2-Commands:
          TPM Main Part 3 Commands, Rev116,
          https://trustedcomputinggroup.org/wp-content/uploads
          /TPM-Main-Part-3-Commands_v1.2_rev116_01032011.pdf,
          Section 16.5";

      }

      leaf version-info {
        type binary;
        description
          "The version info (type TPM_CAP_VERSION_INFO),
         i.e., the 'versionInfo' part of a TPM1.2 Quote2
         operation result.";
        reference
          "TPM1.2-Commands:
          TPM Main Part 3 Commands, Rev116,
          https://trustedcomputinggroup.org/wp-content/uploads
          /TPM-Main-Part-3-Commands_v1.2_rev116_01032011.pdf,
          Section 16.5";

      }

      leaf sig {
        type binary;
        description
          "The signature generated across the signed data,
         i.e., the 'sig' part of a TPM1.2 Quote2 operation
         result.";
        reference
          "TPM1.2-Commands:
          TPM Main Part 3 Commands, Rev116,
          https://trustedcomputinggroup.org/wp-content/uploads
          /TPM-Main-Part-3-Commands_v1.2_rev116_01032011.pdf,
          Section 16.5";

      }
    }  // grouping tpm12-attestation

    grouping tpm20-attestation {
      description
        "Contains an instance of cryptoprocessor measurements signed
       according to TPM 2.0.  It is supplemented by unsigned
       Attester information.";
      leaf quote-data {
        type binary;
        mandatory true;
        description
          "A hash of the latest PCR values (and the hash algorithm
         used) that have been returned from an Attester for the
         selected PCRs and hash algorithms.";
        reference
          "TPM2.0-Structures:
          Trusted Platform Module Library Part 2:  Structures,
          Revision 01.83, https://trustedcomputinggroup.org/
          wp-content/uploads/TPM-2.0-1.83-Part-2-Structures.pdf,
          Section 10.12.1";

      }

      leaf quote-signature {
        type binary;
        description
          "Quote signature returned by TPM Quote.  The signature was
         generated using the key associated with the
         certificate 'name'.";
        reference
          "TPM2.0-Structures:
          Trusted Platform Module Library Part 2:  Structures,
          Revision 01.83, https://trustedcomputinggroup.org/
          wp-content/uploads/TPM-2.0-1.83-Part-2-Structures.pdf,
          Section 11.2.1";

      }

      uses node-uptime;

      list unsigned-pcr-values {
        description
          "PCR values in each PCR bank.  This might appear redundant
         with the TPM2B_DIGEST, but that digest is calculated across
         multiple PCRs.  Having to verify across multiple PCRs does
         not necessarily make it easy for a Verifier to appraise just
         the minimum set of PCR information that has changed since
         the last received TPM2B_DIGEST.  Put another way, why should
         a Verifier reconstruct the proper value of all PCR Quotes
         when only a single PCR has changed?
         To help this happen, if the Attester does know specific PCR
         values, the Attester can provide these individual values via
         'unsigned-pcr-values'.  By comparing this information to
         what has previously been validated, it is possible for a
         Verifier to confirm the Attester's signature while
         eliminating significant processing.  Note that there should
         never be a result where an unsigned PCR value differs from
         what may be reconstructed from within the PCR quote and
         the event logs.
         If there is a difference, a signed result that has been
         verified from retrieved logs is considered definitive.";
        uses tpm20-hash-algo;

        list pcr-values {
          key "pcr-index";
          description
            "List of one PCR bank.";
          leaf pcr-index {
            type pcr;
            description "PCR index number.";
          }

          leaf pcr-value {
            type binary;
            description "PCR value.";
            reference
              "TPM2.0-Structures:
              Trusted Platform Module Library Part 2:  Structures,
              Revision 01.83, https://trustedcomputinggroup.org/
              wp-content/uploads/TPM-2.0-1.83-Part-2-Structures.pdf,
              Section 10.9.7";

          }
        }  // list pcr-values
      }  // list unsigned-pcr-values
    }  // grouping tpm20-attestation

    grouping log-identifier {
      description
        "Identifier for type of log to be retrieved.";
      leaf log-type {
        type identityref {
          base attested_event_log_type;
        }
        mandatory true;
        description
          "The corresponding identity of the measurement log type.";
      }
    }  // grouping log-identifier

    grouping boot-event-log {
      description
        "Defines a specific instance of an event log entry
       and corresponding to the information used to
       extend the PCR.";
      leaf event-number {
        type uint32;
        description
          "Unique event number of this event, which monotonically
         increases within a given event log.  The maximum event
         number should not be reached, nor is wrapping back to
         an earlier number supported.";
      }

      leaf event-type {
        type uint32;
        description "BIOS log event type.";
        reference
          "BIOS-Log:
          TCG PC Client Platform Firmware Profile Specification,
          https://trustedcomputinggroup.org/wp-content/uploads/
          TCG-PC-Client-Platform-Firmware-Profile-Version-1.06-
          Revision-52_pub-2.pdf, Section 10.4.1";

      }

      leaf pcr-index {
        type pcr;
        description
          "Defines the PCR index that this event extended.";
      }

      list digest-list {
        description "Hash of event data.";
        leaf hash-algo {
          type identityref {
            base taa:hash;
          }
          description
            "The hash scheme that is used to compress the event data in
           each of the leaf-list digest items.";
        }

        leaf-list digest {
          type binary;
          description
            "The hash of the event data using the algorithm of the
           'hash-algo' against 'event data'.";
        }
      }  // list digest-list

      leaf event-size {
        type uint32;
        description
          "Size of the event data.";
      }

      leaf-list event-data {
        type binary;
        description
          "The event data.  This is a binary structure
         of size 'event-size'. For more on what
         might be recorded within this object
         see BIOS-Log, Section 10, which details
         viable events that might be recorded.";
        reference
          "BIOS-Log:
          TCG PC Client Platform Firmware Profile Specification,
          https://trustedcomputinggroup.org/wp-content/uploads/
          TCG-PC-Client-Platform-Firmware-Profile-Version-1.06-
          Revision-52_pub-2.pdf, Section 10";

      }
    }  // grouping boot-event-log

    grouping bios-event-log {
      description
        "Measurement log created by the BIOS/UEFI.";
      list bios-event-entry {
        key "event-number";
        description
          "Ordered list of the TCG-described event log
         that extended the PCRs in the order they
         were logged.";
        uses boot-event-log;
      }  // list bios-event-entry
    }  // grouping bios-event-log

    grouping ima-event {
      description
        "Defines a hash log extend event for IMA measurements.";
      reference
        "CEL:
        Canonical Event Log Format,
        https://www.trustedcomputinggroup.org/wp-content/uploads/
        TCG_IWG_CEL_v1_r0p41_pub.pdf, Section 4.3";

      leaf event-number {
        type uint64;
        description
          "Unique event number of this event, which monotonically
         increases.  The maximum event number should not be
         reached, nor is wrapping back to an earlier number
         supported.";
      }

      leaf ima-template {
        type string;
        description
          "Name of the template used for event logs,
         e.g., ima, ima-ng, ima-sig.";
      }

      leaf filename-hint {
        type string;
        description
          "File name (including the path) that was measured.";
      }

      leaf filedata-hash {
        type binary;
        description
          "Hash of filedata as updated based upon the
         filedata-hash-algorithm.";
      }

      leaf filedata-hash-algorithm {
        type string;
        description
          "Algorithm used for filedata-hash.";
      }

      leaf template-hash-algorithm {
        type string;
        description
          "Algorithm used for template-hash.";
      }

      leaf template-hash {
        type binary;
        description
          "hash(filedata-hash, filename-hint)";
      }

      leaf pcr-index {
        type pcr;
        description
          "Defines the PCR index that this event extended.";
      }

      leaf signature {
        type binary;
        description
          "Digital file signature that provides a
         fingerprint for the file being measured.";
      }
    }  // grouping ima-event

    grouping ima-event-log {
      description
        "Measurement log created by IMA.";
      list ima-event-entry {
        key "event-number";
        description
          "Ordered list of IMA event logs by event-number.";
        uses ima-event;
      }  // list ima-event-entry
    }  // grouping ima-event-log

    grouping network-equipment-boot-event-log {
      description
        "Measurement log created by Network Equipment Boot.  The
       Network Equipment Boot format is identical to the IMA
       format.  In contrast to the IMA log, the Network Equipment
       Boot log includes every measurable event from an Attester,
       including the boot stages of BIOS, Bootloader, etc. In
       essence, the scope of events represented in this format
       combines the scope of BIOS events and IMA events.";
      list boot-event-entry {
        key "event-number";
        description
          "Ordered list of Network Equipment Boot event logs
         by event-number, using the IMA event format.";
        uses ima-event;
      }  // list boot-event-entry
    }  // grouping network-equipment-boot-event-log

    grouping event-logs {
      description
        "A selector for the log and its type.";
      choice attested_event_log_type {
        mandatory true;
        description
          "Event log type determines the event log's content.";
        case bios {
          if-feature bios;
          description
            "BIOS/UEFI event logs.";
          container bios-event-logs {
            description
              "BIOS/UEFI event logs.";
            uses bios-event-log;
          }  // container bios-event-logs
        }  // case bios

        case ima {
          if-feature ima;
          description "IMA event logs.";
          container ima-event-logs {
            description "IMA event logs.";
            uses ima-event-log;
          }  // container ima-event-logs
        }  // case ima

        case netequip_boot {
          if-feature netequip_boot;
          description
            "Network Equipment Boot event logs.";
          container boot-event-logs {
            description
              "Network Equipment Boot event logs.";
            uses network-equipment-boot-event-log;
          }  // container boot-event-logs
        }  // case netequip_boot
      }  // choice attested_event_log_type
    }  // grouping event-logs

    rpc tpm12-challenge-response-attestation {
      if-feature taa:tpm12;
      description
        "This RPC accepts the input for TSS TPM 1.2 commands made to
       the attesting device.";
      input {
        container tpm12-attestation-challenge {
          description
            "This container includes every information element defined
           in the reference challenge-response interaction model for
           remote attestation.  Corresponding values are based on
           TPM 1.2 structure definitions";
          uses tpm12-pcr-selection;

          uses nonce;

          leaf-list certificate-name {
            if-feature tpm:mtpm;
            type certificate-name-ref;
            must
              "/tpm:rats-support-structures/tpm:tpms"
                + "/tpm:tpm[tpm:firmware-version='taa:tpm12']"
                + "/tpm:certificates/"
                + "/tpm:certificate[name=current()]" {
              error-message
                "Not an available TPM1.2 AIK certificate.";
            }
            description
              "When populated, the RPC will only get a Quote for the
             TPMs associated with these certificate(s).";
          }
        }  // container tpm12-attestation-challenge
      }

      output {
        list tpm12-attestation-response {
          unique "certificate-name";
          description
            "The binary output of TPM 1.2 TPM_Quote/TPM_Quote2,
           including the PCR selection and other associated
           attestation evidence metadata.";
          uses certificate-name-ref {
            description
              "Certificate associated with this tpm12-attestation.";
          }

          uses tpm12-attestation;
        }  // list tpm12-attestation-response
      }
    }  // rpc tpm12-challenge-response-attestation

    rpc tpm20-challenge-response-attestation {
      if-feature taa:tpm20;
      description
        "This RPC accepts the input for TSS TPM 2.0 commands of the
       managed device.  Composite devices may contain several TPMs;
       /hardware/component/physical-index from the hardware
       management YANG module is used to refer to dedicated TPMs in
       composite devices; however, devices without TPMs are not
       covered.";
      input {
        container tpm20-attestation-challenge {
          description
            "This container includes every information element defined
           in the reference challenge-response interaction model for
           remote attestation.  Corresponding values are based on
           TPM 2.0 structure definitions.";
          uses nonce;

          uses tpm20-pcr-selection;

          leaf-list certificate-name {
            if-feature tpm:mtpm;
            type certificate-name-ref;
            must
              "/tpm:rats-support-structures/tpm:tpms"
                + "/tpm:tpm[tpm:firmware-version='taa:tpm20']"
                + "/tpm:certificates/"
                + "/tpm:certificate[name=current()]" {
              error-message
                "Not an available TPM2.0 AIK certificate.";
            }
            description
              "When populated, the RPC will only get a Quote for the
             TPMs associated with the certificates.";
          }
        }  // container tpm20-attestation-challenge
      }

      output {
        list tpm20-attestation-response {
          unique "certificate-name";
          description
            "The binary output of TPM2_Quote from one TPM of the
           node which is identified by node-id:  an attestation
           structure (TPMS_ATTEST), including a length, and a
           signature (TPMT_SIGNATURE) over that structure.";
          reference
            "TPM2.0-Structures:
            Trusted Platform Module Library Part 2:  Structures,
            Revision 01.83, https://trustedcomputinggroup.org/
            wp-content/uploads/TPM-2.0-1.83-Part-2-Structures.pdf,
            Section 10.12.12";

          uses certificate-name-ref {
            description
              "Certificate associated with this tpm20-attestation.";
          }

          uses tpm20-attestation;
        }  // list tpm20-attestation-response
      }
    }  // rpc tpm20-challenge-response-attestation

    rpc log-retrieval {
      description
        "Log entries are identified either via indices or by providing
       the last line received.  The number of lines returned can be
       limited.  The type of log is a choice that can be augmented.";
      input {
        uses log-identifier;

        list log-selector {
          description
            "Only log entries that meet all of the provided selection
           criteria are to be returned by the RPC output.";
          leaf-list name {
            type string;
            description
              "Name of one or more unique TPMs on a device.  If this
             object exists, a selection should pull only the objects
             related to these TPM(s).  If it does not exist, all
             qualifying TPMs that are 'hardware-based' equals true
             on the device are selected.  When this selection
             criteria is provided, it will be considered as a logical
             AND with any other selection criteria provided.";
          }

          choice index-type {
            description
              "Last log entry received, log index number, or
             timestamp.";
            case last-entry {
              description
                "The last entry of the log already retrieved.";
              leaf last-entry-value {
                type binary;
                description
                  "Content of a log event that matches 1:1 with a
                 unique event record contained within the log.  Log
                 entries after this will be passed to the
                 requester.  Note: if log entry values are not
                 unique, this MUST return an error.";
              }
            }  // case last-entry

            case index {
              description
                "Numeric index of the last log entry retrieved, or
               zero.";
              leaf last-index-number {
                type uint64;
                description
                  "The last numeric index number of a log entry.
                 Zero means to start at the beginning of the log.
                 Entries after this will be passed to the
                 requester.";
              }
            }  // case index

            case timestamp {
              description
                "Timestamp from which to start the extraction.";
              leaf timestamp {
                type yang:date-and-time;
                description
                  "Timestamp from which to start the extraction.  The
                 next log entry after this timestamp is to
                 be sent.";
              }
            }  // case timestamp
          }  // choice index-type

          leaf log-entry-quantity {
            type uint16;
            description
              "The number of log entries to be returned. If omitted, it
             means all of them.";
          }
        }  // list log-selector
      }

      output {
        container system-event-logs {
          description
            "The requested data of the measurement event logs.";
          list node-data {
            unique "name";
            description
              "Event logs of a node in a distributed system
             identified by the node name.";
            uses tpm-name;

            uses node-uptime;

            container log-result {
              description
                "The requested entries of the corresponding log.";
              uses event-logs;
            }  // container log-result
          }  // list node-data
        }  // container system-event-logs
      }
    }  // rpc log-retrieval

    container rats-support-structures {
      description
        "The datastore definition enabling Verifiers or Relying
       Parties to discover the information necessary to use the
       remote attestation RPCs appropriately.";
      container compute-nodes {
        if-feature tpm:mtpm;
        description
          "Holds the set of device subsystems/components in this
         composite device that support TPM operations.";
        list compute-node {
          key "node-id";
          unique "node-name";
          config false;
          min-elements 2;
          description
            "A component within this composite device that
           supports TPM operations.";
          leaf node-id {
            type string;
            description
              "ID of the compute node, such as Board Serial Number.";
          }

          leaf node-physical-index {
            if-feature hw:entity-mib;
            type int32 {
              range "1..2147483647";
            }
            config false;
            description
              "The entPhysicalIndex for the compute node.";
            reference
              "RFC 6933: Entity MIB (Version 4) - entPhysicalIndex";

          }

          leaf node-name {
            type string;
            description
              "Name of the compute node.";
          }

          leaf node-location {
            type string;
            description
              "Location of the compute node, such as slot number.";
          }
        }  // list compute-node
      }  // container compute-nodes

      container tpms {
        description
          "Holds the set of TPMs within an Attester.";
        list tpm {
          key "name";
          unique "path";
          description
            "A list of TPMs in this composite device that RATS
           can be conducted with.";
          uses tpm-name;

          leaf hardware-based {
            type boolean;
            config false;
            mandatory true;
            description
              "System-generated indication of whether this is a
             hardware-based TPM.";
          }

          leaf physical-index {
            if-feature hw:entity-mib;
            type int32 {
              range "1..2147483647";
            }
            config false;
            description
              "The entPhysicalIndex for the TPM.";
            reference
              "RFC 6933: Entity MIB (Version 4) - entPhysicalIndex";

          }

          leaf path {
            type string;
            config false;
            description
              "Device path to a unique TPM on a device.  This can
             change across reboots.";
          }

          leaf compute-node {
            if-feature tpm:mtpm;
            type compute-node-ref;
            config false;
            mandatory true;
            description
              "Indicates the compute node measured by this TPM.";
          }

          leaf manufacturer {
            type string;
            config false;
            description
              "TPM manufacturer name.";
          }

          leaf firmware-version {
            type identityref {
              base taa:cryptoprocessor;
            }
            mandatory true;
            description
              "Identifies the cryptoprocessor API set supported.  This
             is automatically configured by the device and should not
             be changed.";
          }

          uses tpm12-hash-algo {
            when
              "derived-from-or-self(firmware-version, 'taa:tpm12')";
            if-feature taa:tpm12;
            refine tpm12-hash-algo {
              description
                "The hash algorithm overwrites the default used for
               PCRs on this TPM1.2-compliant cryptoprocessor.";
            }
          }

          leaf-list tpm12-pcrs {
            when
              "derived-from-or-self(../firmware-version, "
                + "'taa:tpm12')";
            if-feature taa:tpm12;
            type pcr;
            description
              "The PCRs that may be extracted from this TPM1.2-
             compliant cryptoprocessor.";
          }

          list tpm20-pcr-bank {
            when
              "derived-from-or-self(../firmware-version, "
                + "'taa:tpm20')";
            if-feature taa:tpm20;
            key "tpm20-hash-algo";
            description
              "Specifies the list of PCRs that may be extracted for
             a specific hash algorithm on this TPM2-compliant
             cryptoprocessor.  A bank is a set of PCRs that are
             extended using a particular hash algorithm.";
            reference
              "TPM2.0-Structures:
              Trusted Platform Module Library Part 2:  Structures,
              Revision 01.83, https://trustedcomputinggroup.org/
              wp-content/uploads/TPM-2.0-1.83-Part-2-Structures.pdf,
              Section 10.9.7";

            leaf tpm20-hash-algo {
              type identityref {
                base taa:hash;
              }
              must
                '/tpm:rats-support-structures'
                  + '/tpm:attester-supported-algos'
                  + '/tpm:tpm20-hash' {
                error-message
                  "This platform does not support "
                    + "tpm20-hash-algo";
              }
              description
                "The hash scheme actively being used to hash
               one or more TPM2.0 PCRs.";
            }

            leaf-list pcr-index {
              type pcr;
              description
                "Defines which TPM2.0 PCRs are available to be
               extracted.";
            }
          }  // list tpm20-pcr-bank

          leaf status {
            type enumeration {
              enum "operational" {
                value 0;
                description
                  "The TPM currently is running normally and
                 is ready to accept and process TPM quotes.";
                reference
                  "TPM2.0-Arch: Trusted Platform Module Library
                  Part 1:  Architecture,
                  https://trustedcomputinggroup.org/wp-content/
                  uploads/TPM-2.0-1.83-Part-1-Architecture.pdf,
                  Section 12";

              }
              enum "non-operational" {
                value 1;
                description
                  "TPM is in a state such as startup or shutdown, which
                 precludes the processing of TPM quotes.";
              }
            }
            config false;
            mandatory true;
            description
              "TPM chip self-test status.";
          }

          container certificates {
            description
              "The TPM's certificates, including EK Certificates
             and Attestation Key Certificates.";
            list certificate {
              key "name";
              description
                "Three types of certificates can be accessed via
               this statement, including Initial Attestation
               Key Certificate, Local Attestation Key Certificate, or
               Endorsement Key Certificate.";
              leaf name {
                type string;
                description
                  "An arbitrary name uniquely identifying a certificate
                 associated with a key within a TPM.";
              }

              leaf keystore-ref {
                if-feature ks:central-keystore-supported;
                if-feature ks:asymmetric-keys;
                type leafref {
                  path "/ks:keystore/ks:asymmetric-keys/ks:asymmetric-key/ks:name";
                }
                description
                  "A reference to a specific certificate of an
                 asymmetric key in the keystore.";
              }

              leaf type {
                type enumeration {
                  enum
                    "endorsement-certificate" {
                    value 0;
                    description
                      "Endorsement Key (EK) Certificate type.";
                    reference
                      "TPM2.0-Key:
                      TPM 2.0 Keys for Device Identity and Attestation
                      https://trustedcomputinggroup.org/wp-content/
                      uploads/TPM-2p0-Keys-for-Device-Identity-
                      and-Attestation_v1_r12_pub10082021.pdf,
                      Section 3.11";

                  }
                  enum
                    "initial-attestation-certificate" {
                    value 1;
                    description
                      "Initial Attestation Key (IAK) Certificate
                     type.";
                    reference
                      "TPM2.0-Key:
                      TPM 2.0 Keys for Device Identity and Attestation
                      https://trustedcomputinggroup.org/wp-content/
                      uploads/TPM-2p0-Keys-for-Device-Identity-
                      and-Attestation_v1_r12_pub10082021.pdf,
                      Section 3.2";

                  }
                  enum
                    "local-attestation-certificate" {
                    value 2;
                    description
                      "Local Attestation Key (LAK) Certificate type.";
                    reference
                      "TPM2.0-Key:
                      TPM 2.0 Keys for Device Identity and Attestation
                      https://trustedcomputinggroup.org/wp-content/
                      uploads/TPM-2p0-Keys-for-Device-Identity-
                      and-Attestation_v1_r12_pub10082021.pdf,
                      Section 3.2";

                  }
                }
                description
                  "Function supported by this certificate from within
                 the TPM.";
              }
            }  // list certificate
          }  // container certificates
        }  // list tpm
      }  // container tpms

      container attester-supported-algos {
        description
          "Identifies which TPM algorithms are available for use on an
         attesting platform.";
        leaf-list tpm12-asymmetric-signing {
          when
            "../../tpm:tpms"
              + "/tpm:tpm[tpm:firmware-version='taa:tpm12']";
          if-feature taa:tpm12;
          type identityref {
            base taa:asymmetric;
          }
          description
            "Platform-supported TPM1.2 asymmetric algorithms.";
        }

        leaf-list tpm12-hash {
          when
            "../../tpm:tpms"
              + "/tpm:tpm[tpm:firmware-version='taa:tpm12']";
          if-feature taa:tpm12;
          type identityref {
            base taa:hash;
          }
          description
            "Platform-supported TPM1.2 hash algorithms.";
        }

        leaf-list tpm20-asymmetric-signing {
          when
            "../../tpm:tpms"
              + "/tpm:tpm[tpm:firmware-version='taa:tpm20']";
          if-feature taa:tpm20;
          type identityref {
            base taa:asymmetric;
          }
          description
            "Platform-supported TPM2.0 asymmetric algorithms.";
        }

        leaf-list tpm20-hash {
          when
            "../../tpm:tpms"
              + "/tpm:tpm[tpm:firmware-version='taa:tpm20']";
          if-feature taa:tpm20;
          type identityref {
            base taa:hash;
          }
          description
            "Platform-supported TPM2.0 hash algorithms.";
        }
      }  // container attester-supported-algos
    }  // container rats-support-structures
  }  // module ietf-tpm-remote-attestation