Internet-Draft | ACVP KAS SSC ECC SP800-56Ar3 | August 2020 |
Hammett | Expires 11 February 2021 | [Page] |
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This document defines the JSON schema for testing KAS-SSC-ECC SP800-56Ar3 implementations with the ACVP specification.¶
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 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 KAS-SSC-ECC SP800-56Ar3 implementations using ACVP.¶
No terms and definitions are listed in this document.¶
The following KAS algorithms MAY be advertised by this ACVP compliant crypto module:¶
KAS-SSC-ECC¶
Other KAS algorithms MAY be advertised by the ACVP module elsewhere.¶
This section describes the design of the tests used to validate KAS-SSC-ECC SP800-56Ar3 implementations.¶
"AFT" - Algorithm Function Test. In the AFT test mode, the IUT SHALL act as a party in the Key Agreement with the ACVP server. The server SHALL generate and provide all necessary information for the IUT to compute a shared secret z
; both the server and IUT MAY act as party U/V.¶
"VAL" - Validation test. In the VAL test mode, The ACVP server MUST generate a complete (from both party U and party V's perspectives) shared secret z
, and expects the IUT to be able to determine if that shared secret is valid. Various types of conditions/errors MUST be introduced in varying portions of the key agreement process (changed Z, Z with leading zero nibble, etc), that the IUT MUST be able to detect and report on.¶
The tests described in this document have the intention of ensuring an implementation is conformant to SP800-56Ar3 KAS Shared Secret Computation (SSC).¶
SP 800-56a - 4.1 Key Establishment Preparations. The ACVP server is responsible for generating domain parameters as per the IUT's capability registration.¶
SP 800-56a - 4.2 Key-Agreement Process. Both the ACVP server and IUT participate in the shared secret computation. The server and IUT can both take the roles of party U/V, and as such the "performer" of steps depicted in "Figure 2: Key Agreement process" can vary.¶
SP 800-56a - 5.6 Domain Parameters. Domain Parameter Generation SHALL be performed solely from the ACVP server, with constraints from the IUTs capabilities registration. The same set of domain parameters SHALL generate all keypairs (party U/V, static/ephemeral) for a single test case.¶
SP 800-56a - 5.6 Key-Pair Generation. While Key-Pairs are used in each KAS scheme, the generation of said key-pairs is out of scope for KAS testing. Random tests from the VAL groups, MAY inject bad keypairs that the IUT MUST be able detect. These random tests are only present in groups given appropriate assurance functions see: Section 3.3¶
SP 800-56a - 4.3 DLC-based Key-Transport Process / 5.7 DLC Primitives. Depending on the scheme used, either Diffie Hellman or MQV SHALL be used to negotiate a shared secret of z. Testing and validation of such key exchanges is covered under their respective schemes.¶
SP 800-56a - 6 Key Agreement Schemes. All schemes specified in referenced document are supported for validation with the ACVP server.¶
KAS SSC testing only covers testing of SP800-56Ar3 through the computation of a shared secret z
. Additional functions of KAS as a whole such as KDF, KC, etc. MAY be covered within the scope of the full KAS testing; please see that document for further details.¶
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 KAS-SSC-ECC SP800-56Ar3 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.¶
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¶
JSON Property | Description | JSON Type |
---|---|---|
algorithm | a prerequisite algorithm | string |
valValue | algorithm validation number | string |
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¶
The KAS-SSC-ECC SP800-56Ar3 mode capabilities are advertised as JSON objects within a root "algorithm" object.¶
A registration SHALL use these properties:¶
JSON Property | Description | JSON Type | Valid Values |
---|---|---|---|
algorithm | Name of the algorithm to be validated | string | "KAS-SSC-ECC" |
revision | ACVP Test version | string | "SP800-56Ar3" |
prereqVals | Prerequisites of the algorithm | object | See Section 7.1 |
scheme | Array of schemes supported | array of objects | See Section 7.2.1 |
domainParameterGenerationMethods | Array of strings representing the supported means of generating domain parameters | array of strings | See Section 7.2.2 |
scheme | Array of schemes supported | dictionary | See Section 7.2.1 |
hashFunctionZ | Optional hash function to apply to the shared secret z in instances where the IUT is unable to return the z in the clear. |
string | See Section 7.2.3 |
Schemes MUST be registered as a dictionary (key/value pairs) where the key is a valid Section 7.2.1.1, and the value is a Section 7.2.1.2.¶
The scheme object is made up of the following properties:¶
JSON Property | Description | JSON Type | Valid Values |
kasRole | The roles the IUT can support for the scheme | array of string | "initiator", "responder" |
An optional hash function that should be applied to z
from both the ACVP server and IUT for comparison purposes. The provided `hashFunctionZ's security strength MUST be at least as strong as the greatest security strength domain parameter selected from Section 7.2.2¶
The following hash functions MAY be advertised by an ACVP compliant server:¶
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 algorithm defined during the capability exchange. This section describes the JSON schema for a test vector set used with KAS-SSC-ECC SP800-56Ar3 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 exchange | string |
mode | Mode defined in the capability exchange | string |
revision | Protocol test revision selected | string |
testGroups | Array of test groups containing test data, see Section 8.1 | array |
An example of this would look like this¶
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 KAS-SSC-ECC SP800-56Ar3 JSON elements of the Test Group JSON object¶
JSON Values | Description | JSON Type |
---|---|---|
tgId | Test group identifier | integer |
testType | Describes the operation the client should perform on the tests data | string |
domainParameterGenerationMode | The curve in use for key generation for the test group | string |
scheme | KAS scheme under test | string |
kasRole | The IUT role under test | string |
hashFunctionZ | The hash function applied to z (optional) |
string |
tests | Array of individual test cases | See Section 8.2 |
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.¶
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 KAS-SSC-ECC SP800-56Ar3 test vector.¶
JSON Values | Description | JSON Type |
---|---|---|
tcId | Test case identifier | integer |
staticPublicServerX | The server static public key X. Optional depending on scheme and test type. | hex |
staticPublicServerY | The server static public key Y. Optional depending on scheme and test type. | hex |
ephemeralPublicServerX | The server ephemeral public key X. Optional depending on scheme and test type. | hex |
ephemeralPublicServerY | The server ephemeral public key Y. Optional depending on scheme and test type. | hex |
staticPrivateIut | The IUT static private key. Optional depending on scheme and test type. | hex |
staticPublicIutX | The IUT static public key X. Optional depending on scheme and test type. | hex |
staticPublicIutY | The IUT static public key Y. Optional depending on scheme and test type. | hex |
ephemeralPrivateIut | The IUT ephemeral private key. Optional depending on scheme and test type. | hex |
ephemeralPublicIutX | The IUT ephemeral public key X. Optional depending on scheme and test type. | hex |
ephemeralPublicIutY | The IUT ephemeral public key Y. Optional depending on scheme and test type. | hex |
z | The computed shared secret. Included for VAL tests when registered without a hashFunctionZ
|
hex |
hashZ | The hashed computed shared secret. Included for VAL tests when registered with a hashFunctionZ
|
hex |
Here is an abbreviated yet fully constructed example of the prompt¶
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.¶
JSON Property | Description | JSON Type |
---|---|---|
acvVersion | The version of the protocol | string |
vsId | The vector set identifier | integer |
testGroups | The test group data | array |
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 |
The following table describes the JSON object that represents a test case response for a KAS-SSC-ECC SP800-56Ar3.¶
JSON Property | Description | JSON Type |
---|---|---|
tcId | The test case identifier | integer |
testPassed | Was the provided z or hashZ valid? Only valid for the "VAL" test type. |
boolean |
staticPublicIutX | The IUT static public key X. Optional depending on scheme and test type. | hex |
staticPublicIutY | The IUT static public key Y. Optional depending on scheme and test type. | hex |
ephemeralPublicIutX | The IUT ephemeral public key X. Optional depending on scheme and test type. | hex |
ephemeralPublicIutY | The IUT ephemeral public key Y. Optional depending on scheme and test type. | hex |
z | The shared secret z . Only included for "AFT" test type when a hashFunctionZ is not in use. |
hex |
hashZ | The shared secret z run through a hash function. Only included for "AFT" test type when a hashFunctionZ is in use. |
hex |
Here is an abbreviated example of the response¶
There are no additional security considerations outside of those outlined in the ACVP document.¶
This document does not require any action by IANA.¶