Network Working Group C. Celi, Ed. Internet-Draft 16 April 2026 Intended status: Informational Expires: 18 October 2026 ACVP SP800-108 Key Derivation Function JSON Specification draft-gold-acvp-kdf-01 Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 18 October 2026. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Table of Contents 1. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 2 2. Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 4. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. Notation conventions . . . . . . . . . . . . . . . . . . 3 4.2. Terms and Definitions . . . . . . . . . . . . . . . . . . 3 4.2.1. Prompt . . . . . . . . . . . . . . . . . . . . . . . 3 4.2.2. Registration . . . . . . . . . . . . . . . . . . . . 3 4.2.3. Response . . . . . . . . . . . . . . . . . . . . . . 3 Celi Expires 18 October 2026 [Page 1] Internet-Draft ACVP KDFs April 2026 4.2.4. Test Case . . . . . . . . . . . . . . . . . . . . . . 3 4.2.5. Test Group . . . . . . . . . . . . . . . . . . . . . 4 4.2.6. Test Vector Set . . . . . . . . . . . . . . . . . . . 4 4.2.7. Validation . . . . . . . . . . . . . . . . . . . . . 4 5. Supported SP 800-108 KDFs . . . . . . . . . . . . . . . . . . 4 6. Test Types and Test Coverage . . . . . . . . . . . . . . . . 4 6.1. Test Types . . . . . . . . . . . . . . . . . . . . . . . 4 6.2. Test Coverage . . . . . . . . . . . . . . . . . . . . . . 4 6.2.1. Requirements Covered . . . . . . . . . . . . . . . . 5 6.2.2. Requirements Not Covered . . . . . . . . . . . . . . 5 7. Capabilities Registration . . . . . . . . . . . . . . . . . . 5 7.1. Prerequisites . . . . . . . . . . . . . . . . . . . . . . 5 7.2. Required Prerequisite Algorithms for SP 800-108r1 KDF Validations . . . . . . . . . . . . . . . . . . . . . . . 6 7.3. Property Registration . . . . . . . . . . . . . . . . . . 7 7.3.1. Supported SP 800-108r1 KDF Modes . . . . . . . . . . 8 7.3.2. Supported KDF Modes Capabilities . . . . . . . . . . 9 7.3.3. Supported SP 800-108r1 KDF MACs . . . . . . . . . . . 11 7.4. Registration Example . . . . . . . . . . . . . . . . . . 12 8. Test Vectors . . . . . . . . . . . . . . . . . . . . . . . . 16 8.1. Test Groups JSON Schema . . . . . . . . . . . . . . . . . 18 8.2. Test Case JSON Schema . . . . . . . . . . . . . . . . . . 19 8.3. Example Test Vector JSON Object . . . . . . . . . . . . . 20 9. Test Vector Responses . . . . . . . . . . . . . . . . . . . . 22 9.1. Example Test Vector Response JSON . . . . . . . . . . . . 25 10. Security Considerations . . . . . . . . . . . . . . . . . . . 26 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 12. Normative References . . . . . . . . . . . . . . . . . . . . 26 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 27 1. Acknowledgements There are no acknowledgements. 2. Abstract This document defines the JSON schema for testing SP 800-108 KDF implementations with the ACVP specification. 3. Introduction The Automated Crypto Validation Protocol (ACVP) defines a mechanism to automatically verify the cryptographic implementation of a software or hardware crypto module. The ACVP specification defines how a crypto module communicates with an ACVP server, including crypto capabilities negotiation, session management, authentication, vector processing and more. The ACVP specification does not define algorithm specific JSON constructs for performing the crypto Celi Expires 18 October 2026 [Page 2] Internet-Draft ACVP KDFs April 2026 validation. A series of ACVP sub-specifications define the constructs for testing individual crypto algorithms. Each sub- specification addresses a specific class of crypto algorithms. This sub-specification defines the JSON constructs for testing SP 800-108 KDF implementations using ACVP. This document is a work-product of the NIST (https://www.nist.gov/) Cryptographic Algorithm Validation Program (https://csrc.nist.gov/projects/cryptographic-algorithm-validation- program) (CAVP). Please communicate questions and feedback concerning this document to the CAVP by opening an issue on the usnistgov/ACVP GitHub repository at https://github.com/usnistgov/ACVP/issues. 4. Conventions 4.1. Notation conventions 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 of [RFC2119] and [RFC8174] when, and only when, they appear in all capitals, as shown here. 4.2. Terms and Definitions 4.2.1. Prompt JSON sent from the server to the client describing the tests the client performs 4.2.2. Registration The initial request from the client to the server describing the capabilities of one or several algorithm, mode and revision combinations 4.2.3. Response JSON sent from the client to the server in response to the prompt 4.2.4. Test Case An individual unit of work within a prompt or response Celi Expires 18 October 2026 [Page 3] Internet-Draft ACVP KDFs April 2026 4.2.5. Test Group A collection of test cases that share similar properties within a prompt or response 4.2.6. Test Vector Set A collection of test groups under a specific algorithm, mode, and revision 4.2.7. Validation JSON sent from the server to the client that specifies the correctness of the response 5. Supported SP 800-108 KDFs The following key derivation functions MAY be advertised by the ACVP compliant cryptographic module: * KDF / / 1.0 * KDF / KMAC / Sp800-108r1 6. Test Types and Test Coverage This section describes the design of the tests used to validate SP 800-108 KDF implementations. 6.1. Test Types There is only one test type: functional tests. Each has a specific value to be used in the testType field. The testType field definition is: * "AFT" - Algorithm Functional Test. These tests can be processed by the client using a normal 'derive_key' operation. AFTs cause the implementation under test to exercise normal operations on a single block, multiple blocks, or partial blocks. In all cases, random data is used. The functional tests are designed to verify that the logical components of the key deriviation process are operating correctly. 6.2. Test Coverage The tests described in this document have the intention of ensuring an implementation is conformant to [SP800-108r1]. Celi Expires 18 October 2026 [Page 4] Internet-Draft ACVP KDFs April 2026 6.2.1. Requirements Covered * The ACVP server tests the IUT's ability to derive keying material using the "modes of iteration" defined in sections 5.1, 5.2 and 5.3 of [SP800-108r1]. The server supports testing the IUT against the various MACs or PRFs listed in Section 7.3.3. It also supports testing varying 1) the location of the counter within the input data, 2) the length of the derived keying material, and 3) the counter length. 6.2.2. Requirements Not Covered * The tests described in this document do not validate the construction of the fixed input data string described in [SP800-108r1] Sections 5, 7.5 and 7.6. 7. Capabilities Registration ACVP requires crypto modules to register their capabilities. This allows the crypto module to advertise support for specific algorithms, notifying the ACVP server which algorithms need test vectors generated for the validation process. This section describes the constructs for advertising support of SP 800-108 KDF algorithms to the ACVP server. The algorithm capabilities MUST be advertised as JSON objects within the 'algorithms' value of the ACVP registration message. The 'algorithms' value is an array, where each array element is an individual JSON object defined in this section. The 'algorithms' value is part of the 'capability_exchange' element of the ACVP JSON registration message. See the ACVP specification [ACVP] for more details on the registration message. 7.1. Prerequisites Each algorithm implementation MAY rely on other cryptographic primitives. For example, RSA Signature algorithms depend on an underlying hash function. Each of these underlying algorithm primitives must be validated, either separately or as part of the same submission. ACVP provides a mechanism for specifying the required prerequisites: Prerequisites, if applicable, MUST be submitted in the registration as the prereqVals JSON property array inside each element of the algorithms array. Each element in the prereqVals array MUST contain the following properties Celi Expires 18 October 2026 [Page 5] Internet-Draft ACVP KDFs April 2026 +===============+=============================+===========+ | JSON Property | Description | JSON Type | +===============+=============================+===========+ | algorithm | a prerequisite algorithm | string | +---------------+-----------------------------+-----------+ | valValue | algorithm validation number | string | +---------------+-----------------------------+-----------+ Table 1: Prerequisite Properties A "valValue" of "same" SHALL be used to indicate that the prerequisite is being met by a different algorithm in the capability exchange in the same registration. An example description of prerequisites within a single algorithm capability exchange looks like this "prereqVals": [ { "algorithm": "Alg1", "valValue": "Val-1234" }, { "algorithm": "Alg2", "valValue": "same" } ] 7.2. Required Prerequisite Algorithms for SP 800-108r1 KDF Validations Each SP800-108r1 KDF implementation relies on other cryptographic primitives. For example, the KDF must utilize an underlying MAC algorithm. Each of these underlying algorithm primitives must be validated, either separately or as part of the same submission. ACVP provides a mechanism for specifying the required prerequisites: Celi Expires 18 October 2026 [Page 6] Internet-Draft ACVP KDFs April 2026 +==============+================+=====================+============+ | JSON Value | Description | JSON Type | Valid | | | | | Values | +==============+================+=====================+============+ | algorithm | A prerequisite | string | AES, DRBG, | | | algorithm | | CMAC, HMAC | +--------------+----------------+---------------------+------------+ | valValue | Algorithm | string | Actual | | | validation | | number or | | | number | | "same" | +--------------+----------------+---------------------+------------+ | prereqAlgVal | Prerequisite | object with | See above | | | algorithm | algorithm and | | | | validation | valValue properties | | +--------------+----------------+---------------------+------------+ | prereqVals | Prerequisite | array of | See above | | | algorithm | prereqAlgVal | | | | validations | objects | | +--------------+----------------+---------------------+------------+ Table 2: SP800-108r1 KDF Required Prerequisites 7.3. Property Registration Each algorithm capability advertised is a self-contained JSON object using the following values. Two algorithm registrations are possible to test SP 800-108r1 KDFs. The first is for the "KDF" / "1.0" which covers the counter, feedback, and double pipeline iteration key derivation functions. The second is for "KDF" / "KMAC" / "Sp800-108r1" which covers the KMAC function when used as a key derivation function, introduced in the new revision, SP 800-108r1. A registration SHALL use these properties: Celi Expires 18 October 2026 [Page 7] Internet-Draft ACVP KDFs April 2026 +==============+=====================+==============+===============+ | JSON | Description | JSON Type | Valid Values | | Property | | | | +==============+=====================+==============+===============+ | algorithm | The KDF to be | string | "KDF" | | | validated. | | | +--------------+---------------------+--------------+---------------+ | mode | The KDF mode to be | string | "KMAC" or "" | | | validated. | | | +--------------+---------------------+--------------+---------------+ | revision | The algorithm | string | "1.0" when | | | testing revision | | "mode" is not | | | to use. | | included, or | | | | | "Sp800-108r1" | | | | | when "mode" | | | | | is set to | | | | | "KMAC" | +--------------+---------------------+--------------+---------------+ | prereqVals | Prerequisite | array of | See | | | algorithm | prereqAlgVal | Section 7.2 | | | validations | objects | | +--------------+---------------------+--------------+---------------+ | capabilities | Array of JSON | array of | See | | | objects, each with | JSON objects | Section 7.3.2 | | | fields pertaining | | | | | to the KDF mode | | | | | identified | | | | | uniquely by the | | | | | combination of the | | | | | "kdfMode" and | | | | | indicated | | | | | properties | | | +--------------+---------------------+--------------+---------------+ Table 3: Registration Properties 7.3.1. Supported SP 800-108r1 KDF Modes The following SP800-108 KDF modes or "modes of iteration" may be advertised by the ACVP compliant crypto module as the "kdfMode" property: * counter * feedback * double pipeline iteration Celi Expires 18 October 2026 [Page 8] Internet-Draft ACVP KDFs April 2026 7.3.2. Supported KDF Modes Capabilities The KDF mode capabilities are advertised as JSON objects within the 'capabilities' value of the ACVP registration message - see Table 2. The 'capabilities' value is an array, where each array element is a JSON object corresponding to a particular KDF mode defined in this section. The 'capabilities' value is part of the 'capability_exchange' element of the ACVP JSON registration message. See the ACVP specification [ACVP] for details on the registration message. Each KDF mode's capabilities are advertised as JSON objects. The following table describes the capabilities that may be advertised by the ACVP compliant crypto module for "KDF" / / "1.0": +===================+======================+=========+==============+ | JSON Value | Description | JSON | Valid Values | | | | Type | | +===================+======================+=========+==============+ | kdfMode | The type of | string | See Section | | | SP800-108r1 KDF or | | 7.3.1 | | | "mode of iteration" | | | +-------------------+----------------------+---------+--------------+ | macMode | The MAC or PRF | array | See Section | | | algorithm used | of | 7.3.3 | | | | string | | +-------------------+----------------------+---------+--------------+ | supportedLengths | The supported | domain | Min: 1, Max: | | | derived keying | | 4096 | | | material lengths in | | | | | bits | | | +-------------------+----------------------+---------+--------------+ | fixedDataOrder | Describes where the | array | Any non- | | | counter appears in | | empty subset | | | the fixed data | | of {"none", | | | | | "after fixed | | | | | data", | | | | | "before | | | | | fixed data", | | | | | "middle | | | | | fixed data", | | | | | "before | | | | | iterator"} | +-------------------+----------------------+---------+--------------+ | counterLength | The length of the | array | Any non- | | | counter in bits | | empty subset | | | | | of {0, 8, | Celi Expires 18 October 2026 [Page 9] Internet-Draft ACVP KDFs April 2026 | | | | 16, 24, 32} | +-------------------+----------------------+---------+--------------+ | supportsEmptyIv | Whether or not the | boolean | true/false | | | IUT supports an | | | | | empty IV | | | +-------------------+----------------------+---------+--------------+ | requiresEmptyIv | Whether or not the | boolean | true/false | | | IUT requires an | | | | | empty IV | | | +-------------------+----------------------+---------+--------------+ | customKeyInLength | Optional value used | integer | 112-4096 | | | to control the | | | | | length of the keyIn | | | | | produced by the | | | | | ACVP server for the | | | | | capability. This | | | | | field cannot be | | | | | used to alter the | | | | | keyIn length for | | | | | AES/TDES based | | | | | macModes, as the | | | | | keyIns expected by | | | | | those algorithms is | | | | | fixed. | | | +-------------------+----------------------+---------+--------------+ Table 4: KDF Mode Capabilities | NOTE 1: The 'fixedDataOrder' options "none" and "before | iterator" are not valid for "counter" KDF. The | 'fixedDataOrder' option "middle fixed data" is not valid for | "feedback" nor "double pipeline iteration" KDF. | NOTE 2: A 'counterLength' of 0 describes that there is no | counter used. The 0 option is not valid for "counter" KDF. | NOTE 3: When 'counterLength' contains a value of "0", | 'fixedDataOrder' must contain a value of "none" and vice | versus. The following table describes the capabilities that may be advertisd by the ACVP compliant crypto module for "KDF" / "KMAC" / "Sp800-108r1": Celi Expires 18 October 2026 [Page 10] Internet-Draft ACVP KDFs April 2026 +========================+====================+========+===========+ | JSON Value | Description | JSON | Valid | | | | Type | Values | +========================+====================+========+===========+ | macMode | The MAC or PRF | array | See | | | algorithm used | of | Section | | | | string | 7.3.3 | +------------------------+--------------------+--------+-----------+ | keyDerivationKeyLength | The lengths of the | domain | Min: 112, | | | key derivation key | | Max: | | | in bits | | 4096, | | | | | Inc: 8 | +------------------------+--------------------+--------+-----------+ | contextLength | The lengths of the | domain | Min: 8, | | | context field in | | Max: | | | bits | | 4096, | | | | | Inc: 8 | +------------------------+--------------------+--------+-----------+ | labelLength | The lengths of the | domain | Min: 8, | | | label field in | | Max: | | | bits. This field | | 4096, | | | can be excluded if | | Inc: 8 | | | no label is used. | | | +------------------------+--------------------+--------+-----------+ | derivedKeyLength | The lengths of the | domain | Min: 112, | | | derived keys in | | Max: | | | bits | | 4096, | | | | | Inc: 8 | +------------------------+--------------------+--------+-----------+ Table 5: KDF KMAC Mode Capabilities 7.3.3. Supported SP 800-108r1 KDF MACs The following MAC or PRF functions MAY be advertised by an ACVP compliant client * CMAC-AES128 * CMAC-AES192 * CMAC-AES256 * CMAC-TDES * HMAC-SHA1 * HMAC-SHA2-224 Celi Expires 18 October 2026 [Page 11] Internet-Draft ACVP KDFs April 2026 * HMAC-SHA2-256 * HMAC-SHA2-384 * HMAC-SHA2-512 * HMAC-SHA2-512/224 * HMAC-SHA2-512/256 * HMAC-SHA3-224 * HMAC-SHA3-256 * HMAC-SHA3-384 * HMAC-SHA3-512 * KMAC-128 * KMAC-256 | NOTE: The "KMAC-128" and "KMAC-256" options are only allowed | for, and are the only options allowed for, "KDF" / "KMAC" / | "Sp800-108r1". 7.4. Registration Example The following is a example JSON object advertising support for "KDF" / / "1.0". { "algorithm": "KDF", "revision": "1.0", "prereqVals": [ { "algorithm": "SHA", "valValue": "123456" }, { "algorithm": "DRBG", "valValue": "123456" } ], "capabilities": [ { "kdfMode": "counter", "macMode": [ Celi Expires 18 October 2026 [Page 12] Internet-Draft ACVP KDFs April 2026 "CMAC-AES128", "CMAC-AES192", "CMAC-AES256", "CMAC-TDES", "HMAC-SHA-1", "HMAC-SHA2-224", "HMAC-SHA2-256", "HMAC-SHA2-384", "HMAC-SHA2-512" ], "supportedLengths": [ { "min": 8, "max": 1024, "increment": 1 } ], "fixedDataOrder": [ "after fixed data", "before fixed data", "middle fixed data" ], "counterLength": [ 8, 16, 24, 32 ], "supportsEmptyIv": false }, { "kdfMode": "feedback", "macMode": [ "CMAC-AES128", "CMAC-AES192", "CMAC-AES256", "CMAC-TDES", "HMAC-SHA-1", "HMAC-SHA2-224", "HMAC-SHA2-256", "HMAC-SHA2-384", "HMAC-SHA2-512" ], "supportedLengths": [ { "min": 8, "max": 1024, "increment": 1 Celi Expires 18 October 2026 [Page 13] Internet-Draft ACVP KDFs April 2026 } ], "fixedDataOrder": [ "none", "after fixed data", "before fixed data", "before iterator" ], "counterLength": [ 0, 8, 16, 24, 32 ], "supportsEmptyIv": true, "requiresEmptyIv": false }, { "kdfMode": "double pipeline iteration", "macMode": [ "CMAC-AES128", "CMAC-AES192", "CMAC-AES256", "CMAC-TDES", "HMAC-SHA-1", "HMAC-SHA2-224", "HMAC-SHA2-256", "HMAC-SHA2-384", "HMAC-SHA2-512" ], "supportedLengths": [ { "min": 8, "max": 1024, "increment": 1 } ], "fixedDataOrder": [ "none", "after fixed data", "before fixed data", "before iterator" ], "counterLength": [ 0, 8, 16, Celi Expires 18 October 2026 [Page 14] Internet-Draft ACVP KDFs April 2026 24, 32 ], "supportsEmptyIv": false } ] } Figure 1 The following is a example JSON object advertising support for a "KDF" / "KMAC" / "Sp800-108r1". Celi Expires 18 October 2026 [Page 15] Internet-Draft ACVP KDFs April 2026 { "algorithm": "KDF", "mode": "KMAC", "revision": "Sp800-108r1", "macMode": [ "KMAC-128", "KMAC-256" ], "keyDerivationKeyLength": [ { "min": 112, "max": 4096, "increment": 8 } ], "contextLength": [ { "min": 8, "max": 4096, "increment": 8 } ], "labelLength": [ { "min": 8, "max": 4096, "increment": 8 } ], "derivedKeyLength": [ { "min": 112, "max": 4096, "increment": 8 } ] } Figure 2 8. Test Vectors The ACVP server provides test vectors to the ACVP client, which are then processed and returned to the ACVP server for validation. A typical ACVP validation test session would require multiple test vector sets to be downloaded and processed by the ACVP client. Each test vector set represents an individual cryptographic algorithm defined during the capability exchange. This section describes the Celi Expires 18 October 2026 [Page 16] Internet-Draft ACVP KDFs April 2026 JSON schema for a test vector set used with SP 800-108 KDF algorithms. The test vector set JSON schema is a multi-level hierarchy that contains meta data for the entire vector set as well as individual test vectors to be processed by the ACVP client. The following table describes the JSON elements at the top level of the hierarchy. +=============+======================================+===========+ | JSON Values | Description | JSON Type | +=============+======================================+===========+ | acvVersion | Protocol version identifier | string | +-------------+--------------------------------------+-----------+ | vsId | Unique numeric vector set identifier | integer | +-------------+--------------------------------------+-----------+ | algorithm | Algorithm defined in the capability | string | | | exchange | | +-------------+--------------------------------------+-----------+ | mode | Mode defined in the capability | string | | | exchange | | +-------------+--------------------------------------+-----------+ | revision | Protocol test revision selected | string | +-------------+--------------------------------------+-----------+ | testGroups | Array of test group JSON objects, | array | | | which are defined in Section 8.1 | | +-------------+--------------------------------------+-----------+ Table 6: Top Level Test Vector JSON Elements An example of this would look like this [ { "acvVersion": }, { "vsId": 1, "algorithm": "Alg1", "mode": "Mode1", "revision": "Revision1.0", "testGroups": [ ... ] } ] Celi Expires 18 October 2026 [Page 17] Internet-Draft ACVP KDFs April 2026 8.1. Test Groups JSON Schema The testGroups element at the top level in the test vector JSON object is an array of test groups. Test vectors are grouped into similar test cases to reduce the amount of data transmitted in the vector set. For instance, all test vectors that use the same key size would be grouped together. The Test Group JSON object contains meta data that applies to all test vectors within the group. The following table describes the SP 800-108 KDF JSON elements of the Test Group JSON object for "KDF" / / "1.0". +=================+===================================+=========+ | JSON Values | Description | JSON | | | | Type | +=================+===================================+=========+ | tgId | Test group identifier | integer | +-----------------+-----------------------------------+---------+ | kdfMode | The kdfMode used for the test | string | | | group | | +-----------------+-----------------------------------+---------+ | macMode | Psuedorandom function (PRF) HMAC, | string | | | CMAC, or KMAC used | | +-----------------+-----------------------------------+---------+ | counterLocation | "none", "after fixed data", | string | | | "before fixed data", "middle | | | | fixed data", or "before iterator" | | +-----------------+-----------------------------------+---------+ | keyOutLength | Expected length of the derived | integer | | | keying material or key in bits | | +-----------------+-----------------------------------+---------+ | counterLength | Expected length of the counter in | integer | | | bits | | +-----------------+-----------------------------------+---------+ | zeroLengthIv | Whether or not the group utilizes | boolean | | | a null IV | | +-----------------+-----------------------------------+---------+ | testType | Describes the operation being | string | | | performed | | +-----------------+-----------------------------------+---------+ | tests | Array of individual test cases | array | +-----------------+-----------------------------------+---------+ Table 7: Test Group JSON Object | NOTE: The feedback mode KDF counter location of "counter after | iterator" is referenced with the option "before fixed data" in | the 'counterLocation' specification. Celi Expires 18 October 2026 [Page 18] Internet-Draft ACVP KDFs April 2026 For "KDF" / "KMAC" / "Sp800-108r1" the following table describes the JSON elements of the Test Group JSON object. +=============+=========================================+===========+ | JSON Values | Description | JSON Type | +=============+=========================================+===========+ | tgId | Test group identifier | integer | +-------------+-----------------------------------------+-----------+ | macMode | Psuedorandom function (PRF) KMAC used | string | +-------------+-----------------------------------------+-----------+ | testType | Describes the operation being | string | | | performed | | +-------------+-----------------------------------------+-----------+ | tests | Array of individual test cases | array | +-------------+-----------------------------------------+-----------+ Table 8: Test Group JSON Object for "KDF" / "KMAC" / "Sp800-108r1" The 'tgId', 'testType' and 'tests' objects MUST appear in every test group element communicated from the server to the client as a part of a prompt. Other properties are dependent on which 'testType' the group is addressing. 8.2. Test Case JSON Schema Each test group contains an array of one or more test cases. Each test case is a JSON object that represents a single test vector to be processed by the ACVP client. The following table describes the JSON elements for each SP 800-108 KDF "KDF" / / "1.0" test vector. +=============+=============================+===========+ | JSON Values | Description | JSON Type | +=============+=============================+===========+ | tcId | Test case idenfitier | integer | +-------------+-----------------------------+-----------+ | keyIn | Input key | hex | +-------------+-----------------------------+-----------+ | iv | The initialization vector | hex | | | used only for feedback KDFs | | +-------------+-----------------------------+-----------+ Table 9: Test Case JSON Object The following table describes the JSON elements for each "KDF" / "KMAC" / "Sp800-108r1" test vector. Celi Expires 18 October 2026 [Page 19] Internet-Draft ACVP KDFs April 2026 +==================+========================+===========+ | JSON Values | Description | JSON Type | +==================+========================+===========+ | tcId | Test case idenfitier | integer | +------------------+------------------------+-----------+ | keyDerivationKey | Input key | hex | +------------------+------------------------+-----------+ | context | The context value used | hex | +------------------+------------------------+-----------+ | label | The label value used | hex | +------------------+------------------------+-----------+ | derivedKeyLength | The expected length of | integer | | | the derived key | | +------------------+------------------------+-----------+ Table 10: Test Case JSON Object 8.3. Example Test Vector JSON Object The following is a example JSON object for SP 800-108r1 KDF "KDF" / / "1.0" test vectors sent from the ACVP server to the crypto module. Celi Expires 18 October 2026 [Page 20] Internet-Draft ACVP KDFs April 2026 [ { "acvVersion": "v1.0" }, { "vsId": 1564, "algorithm": "counterMode", "revision": "1.0", "testGroups": [{ "tgId": 1, "kdfMode": "counter", "macMode": "CMAC-AES128", "counterLocation": "after fixed data", "keyOutLength": 1024, "counterLength": 8, "tests": [{ "tcId": 1, "keyIn": "5DA38931E8D9174BC3279C8942D2DB82", "deferred": false }, { "tcId": 2, "keyIn": "58F5426A40E3D5D2C94F0F97EB30C739", "deferred": false } ] }] } ] Figure 3 The following is a example JSON object for "KDF" / "KMAC" / "Sp800-108r1" test vectors sent from the ACVP server to the crypto module. Celi Expires 18 October 2026 [Page 21] Internet-Draft ACVP KDFs April 2026 [ { "acvVersion": "v1.0" }, { "vsId": 0, "algorithm": "KDF", "mode": "KMAC", "revision": "Sp800-108r1", "isSample": false, "testGroups": [ { "tgId": 1, "testType": "AFT", "macMode": "KMAC-128", "tests": [ { "tcId": 1, "keyDerivationKey": "FA4E...", "context": "4476...", "label": "146EE...", "derivedKeyLength": 112 }, { "tcId": 2, "keyDerivationKey": "2BE6...", "context": "5E2E...", "label": "0DD6...", "derivedKeyLength": 112 } ] } } ] Figure 4 9. Test Vector Responses After the ACVP client downloads and processes a vector set, it must send the response vectors back to the ACVP server. The following table describes the JSON object that represents a vector set response. Celi Expires 18 October 2026 [Page 22] Internet-Draft ACVP KDFs April 2026 +===============+=============================+===========+ | JSON Property | Description | JSON Type | +===============+=============================+===========+ | acvVersion | The version of the protocol | string | +---------------+-----------------------------+-----------+ | vsId | The vector set identifier | integer | +---------------+-----------------------------+-----------+ | testGroups | The test group data | array | +---------------+-----------------------------+-----------+ Table 11: Vector Set Response Properties An example of this is the following { "acvVersion": "version", "vsId": 1, "testGroups": [ ... ] } The testGroups section is used to organize the ACVP client response in a similar manner to how it receives vectors. Several algorithms SHALL require the client to send back group level properties in their response. This structure helps accommodate that. +===============+===========================+===========+ | JSON Property | Description | JSON Type | +===============+===========================+===========+ | tgId | The test group identifier | integer | +---------------+---------------------------+-----------+ | tests | The test case data | array | +---------------+---------------------------+-----------+ Table 12: Vector Set Group Response Properties An example of this is the following { "tgId": 1, "tests": [ ... ] } The testCase section is used to organize the ACVP client response in a similar manner to how it receives vectors. Several algorithms SHALL require the client to send back group level properties in their response. This structure helps accommodate that. Celi Expires 18 October 2026 [Page 23] Internet-Draft ACVP KDFs April 2026 The following table describes the JSON properties that represent a test case response for "KDF" / / "1.0". +===============+=========================================+=========+ | JSON Property | Description | JSON | | | | Type | +===============+=========================================+=========+ | tcId | The test case identifier | integer | +---------------+-----------------------------------------+---------+ | breakLocation | The bit location in the fixed | integer | | | data where the counter is placed. | | | | breakLocation is only applicable | | | | and SHALL be included for test | | | | cases where counterLocation is | | | | "middle fixed data". | | +---------------+-----------------------------------------+---------+ | fixedData | The fixed input data used by the | hex | | | IUT | | +---------------+-----------------------------------------+---------+ | keyOut | The outputted keying material or | hex | | | key | | +---------------+-----------------------------------------+---------+ Table 13: Test Case Results JSON Properties | NOTE: the fixedData or fixed input data string that is used by | the IUT is needed by the ACVP server to verify that the IUT | correctly derived the keying material. The server does not | validate the correct construction of the fixed input data | string. For guidance on constructing a valid fixed input data | string, please consult [SP800-108r1] Sections 5, 7.5 and 7.6. The following table describes the JSON properties that represent a test case response for "KDF" / "KMAC" / "Sp800-108r1". +===============+======================================+===========+ | JSON Property | Description | JSON Type | +===============+======================================+===========+ | tcId | The test case identifier | integer | +---------------+--------------------------------------+-----------+ | derivedKey | The outputted keying material or key | hex | +---------------+--------------------------------------+-----------+ Table 14: Test Case Results JSON Properties for "KDF" / "KMAC" / "Sp800-108r1" Celi Expires 18 October 2026 [Page 24] Internet-Draft ACVP KDFs April 2026 9.1. Example Test Vector Response JSON The following is an abbreviated example of a JSON object for "KDF" / / "1.0" test results sent from the crypto module to the ACVP server. [ { "acvVersion": }, { "vsId": 1564, "testGroups": [ { "tgId": 1, "tests": [ { "tcId": 1, "keyOut": "94D58F...", "fixedData": "FBF14DF02EE6C7DABCA6EF9AF59BB9A2" } ] } ] } ] Figure 5 | NOTE: Please note that the values used in the example JSON | object are not real values. In particular, the value for the | fixedData property is not an example of a validly formed fixed | input data string. The following is an example of a JSON object for "KDF" / "KMAC" / "Sp800-108r1" test results sent from the crypto module to the ACVP server. Celi Expires 18 October 2026 [Page 25] Internet-Draft ACVP KDFs April 2026 [ { "acvVersion": }, { "vsId": 0, "algorithm": "KDF", "mode": "KMAC", "revision": "Sp800-108r1", "testGroups": [ { "tgId": 1, "tests": [ { "tcId": 1, "derivedKey": "A639..." }, { "tcId": 2, "derivedKey": "A328..." } ] } ] } ] Figure 6 10. Security Considerations There are no additional security considerations outside of those outlined in the ACVP document. 11. IANA Considerations This document does not require any action by IANA. 12. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7991] Hoffman, P., "The "xml2rfc" Version 3 Vocabulary", RFC 7991, RFC 7991, DOI 10.17487/RFC7991, December 2016, . Celi Expires 18 October 2026 [Page 26] Internet-Draft ACVP KDFs April 2026 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", RFC 8174, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [SP800-108] Chen, L., "Recommendation for Key Derivation Using Pseudorandom Functions (Revised)", NIST SP 800-108, October 2009, . [SP800-108r1] Chen, L., "Recommendation for Key Derivation Using Pseudorandom Functions", NIST SP 800-108 Rev. 1, February 2024, . [ACVP] Fussell, B., Vassilev, A., and H. Booth, "Automatic Cryptographic Validation Protocol", ACVP, 1 July 2019. Author's Address Christopher Celi (editor) Email: christopher.celi@nist.gov Celi Expires 18 October 2026 [Page 27]