Added initial support for CMAC #69

NinjaRat84 · 2025-03-27T09:49:27Z

Introduces initial support for the CMAC (Cipher-based Message Authentication Code) algorithm to the cryptography-kotlin library.

NinjaRat84 · 2025-03-27T09:54:54Z

This pull request is up for discussion, since I have a need for CMAC support in this library.
But not comfortable with the structure yet, so therefore a draft.

All input is welcome :)

whyoleg · 2025-03-30T09:49:48Z

Hey!
Thanks for the PR, do you mind making the API similar to HMAC?

NinjaRat84 · 2025-04-08T14:36:00Z

Glad to be of service :)
Similar to this then, or any other things that looks weird?

whyoleg · 2025-04-11T17:44:03Z

I was thinking that it should have the same SignatureVerifier and SignatureGenerator based API there instead of update/reset.

Something like this:

@SubclassOptInRequired(CryptographyProviderApi::class)
public interface CMAC : CryptographyAlgorithm {
    override val id: CryptographyAlgorithmId< CMAC > get() = Companion

    public companion object : CryptographyAlgorithmId<CMAC>("CMAC")

    public fun keyDecoder(): KeyDecoder<Key.Format, Key>
    public fun keyGenerator(keySize: BinarySize): KeyGenerator<Key>

    @SubclassOptInRequired(CryptographyProviderApi::class)
    public interface Key : EncodableKey<Key.Format> {
        public fun signatureGenerator(): SignatureGenerator
        public fun signatureVerifier(): SignatureVerifier

        public enum class Format : KeyFormat { RAW }
    }
}

The only problem I see for now in this API is that we don't declare that it is AES based CMAC.
I don't know if in this case it might be better to call the interface AESCMAC (or even move it under the AES.CMAC).
At this point, I'm not sure, what will be the best API wise, but AES.CMAC placement is my favorite on current moment. In this case, it's only needed to declare the following in AES interface I believe:

    @SubclassOptInRequired(CryptographyProviderApi::class)
    public interface CMAC : AES<CMAC.Key> {
        override val id: CryptographyAlgorithmId<CMAC> get() = Companion

        public companion object : CryptographyAlgorithmId<CMAC>("AES-CMAC")

        @SubclassOptInRequired(CryptographyProviderApi::class)
        public interface Key : CMAC.Key {
            public fun signatureGenerator(): SignatureGenerator
            public fun signatureVerifier(): SignatureVerifier
        }
    }

If you still understand the idea (I know, that my description is a bit messy) and ready to continue working on the PR, I would be glad to help and will try in future to answer questions faster :)

In any case, thanks for the PR!

…SignatureVerifier instead

NinjaRat84 · 2025-04-14T14:31:51Z

So basically this approach instead?

// Dummy data
val key = CryptographyRandom.nextBytes(16)
val salt = CryptographyRandom.nextBytes(16)

// getting default provider
val provider = CryptographyProvider.Default

// getting CMAC algorithm
val cmacProvider = provider.get(AES.CMAC)

// initializing CMAC
val decodedKey = cmacProvider.keyDecoder().decodeFromByteArrayBlocking(Key.Format.RAW, key)
val signFunction = decodedKey.signatureGenerator().createSignFunction()

// Update salt
signFunction.update(salt)

// Finalize CMAC
val derivedKey = signFunction.signToByteArray()

…SignatureVerifier instead

whyoleg · 2025-04-15T18:13:44Z

So basically this approach instead?

Yes, nice, thank you! I know that the naming with sign/verify is not the best (borrowed from WebCrypto), but still it's better to be uniform.

Feel free to convert the PR from draft when it will be ready, so I will do a proper API/implementation review.

NinjaRat84 · 2025-04-17T06:33:21Z

Note: CMAC is only available for OpenSSL3 and JDK with BouncyCastle, not sure what I need to do in order to fix JDK tests to only run for BC.

But should be close to merge-ready now. :)

whyoleg · 2025-04-24T19:09:39Z

Note: CMAC is only available for OpenSSL3 and JDK with BouncyCastle, not sure what I need to do in order to fix JDK tests to only run for BC.

You need to add an additional branch here, saying that it's not supported on specific providers

Also, could you please AES.CMAC here?

whyoleg

One more time, thanks for the PR and a great work!
I've left several comments. Could you take a look?
If you need any help, just ping me!

whyoleg · 2025-04-24T19:10:59Z

cryptography-providers-tests-api/src/commonMain/kotlin/compatibility/Models.kt

@@ -87,3 +87,10 @@ data class DerivedSecretData(
    val input: ByteStringAsString,
    val secret: ByteStringAsString,
 ) : TestData
+
+@Serializable
+data class CmacData(


This should not be needed, and you should be able to reuse SignatureData. You can take a look on HmacCompatibilityTest on how it's used there

whyoleg · 2025-04-24T19:13:19Z

cryptography-providers-tests/src/commonMain/kotlin/testvectors/AesCmacTestvectorsTest.kt

+import dev.whyoleg.cryptography.providers.tests.api.*
+import kotlin.test.*
+
+abstract class AesCmacTestvectorsTest(provider: CryptographyProvider) : AlgorithmTest<AES.CMAC>(AES.CMAC, provider) {


Could you please provide some information, on where those testvectors are coming from?
If they are from RFC, then leave a link like in HMAC tests or if not, a bit of explanation on why those specific values are generated

whyoleg · 2025-04-24T19:18:09Z

cryptography-providers-tests/src/commonMain/kotlin/testvectors/AesCmacTestvectorsTest.kt

+
+abstract class AesCmacTestvectorsTest(provider: CryptographyProvider) : AlgorithmTest<AES.CMAC>(AES.CMAC, provider) {
+
+    private fun testCase(key: ByteArray, salt: ByteArray, expected: ByteArray) {


minor: it would be nice to make the testCase accept hexes and make methods more declarative, easier to read and with less noise (similar to other testvectors tests):

@Test fun testDiversifyKeyCase1() = testCase( keyHex = "2b7e151628aed2a6abf7158809cf4f3c", saltHex = "6bc1bee22e409f96e93d7e117393172a", resultHex = "070a16b46b4d4144f79bdd9dd04a287c" )

whyoleg · 2025-04-24T19:19:13Z

docs/providers/index.md

@@ -59,6 +59,7 @@ For additional limitation please consult provider specific documentation.
 |                                             | SHA3 family      |  ✅  |     ❌     |   ❌   |    ✅     |
 |                                             | ⚠️ RIPEMD160     |  ✅  |     ❌     |   ❌   |    ✅     |
 | **MAC**                                     | HMAC             |  ✅  |     ✅     |   ✅   |    ✅     |
+|                                             | ⚠️ CMAC          |  ✅  |     ❌     |   ❌   |    ✅     |


I believe there is no need to add ⚠️ as it's not that delicate algorithm AFAIK

whyoleg · 2025-04-24T19:19:54Z

tests-publication/build.gradle.kts

@@ -54,7 +54,7 @@ kotlin {
        }
        commonTest.dependencies {
            implementation(kotlin("test"))
-            implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.9.0")
+            implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:2.1.20")


Please revert this, as there is no such coroutines version

whyoleg · 2025-04-24T19:33:11Z

cryptography-providers-tests/src/commonMain/kotlin/default/AesCmacTest.kt

+    }
+
+    @Test
+    fun verifyResult() = runTestWithScope {


minor: it would be nice in default tests to test at least that the size of signature(mac) is 128 bits

whyoleg · 2025-04-24T19:35:19Z

cryptography-providers-tests/src/commonMain/kotlin/compatibility/AesCmacCompatibilityTest.kt

+    AesBasedCompatibilityTest<AES.CMAC.Key, AES.CMAC>(AES.CMAC, provider) {
+
+    @Serializable
+    private data class SignatureParameters(


I believe, that there should be no parameters for CMAC here, so you can just use TestParameters.Empty in place (as in here)

whyoleg · 2025-04-24T19:36:53Z

cryptography-providers-tests/src/commonMain/kotlin/compatibility/AesCmacCompatibilityTest.kt

+                    logger.log { "signature.size = ${signature.size}" }
+
+                    assertTrue(verifier.tryVerifySignatureBlocking(data, signature), "Initial Verify")
+                    api.ciphers.saveData(cipherParametersId, SignatureData(keyReference, data, signature))


api.signatures should be used here (and below in validate)
While at this point it doesn't really matter, I'm planning to implement more type-safe DSL for tests and this will be an issue :)

whyoleg · 2025-04-24T19:37:53Z

cryptography-providers-tests/src/commonMain/kotlin/compatibility/AesCmacCompatibilityTest.kt

+        val parametersList = buildList {
+            // size of IV = 16
+            (List(ivIterations) { ByteString(CryptographyRandom.nextBytes(16)) }).forEach { iv ->
+                generateBoolean { padding ->
+                    val parameters = SignatureParameters(padding)
+                    val id = api.ciphers.saveParameters(parameters)
+                    add(id to parameters)
+                }
+            }
+        }


Suggested change

val parametersList = buildList {

// size of IV = 16

(List(ivIterations) { ByteString(CryptographyRandom.nextBytes(16)) }).forEach { iv ->

generateBoolean { padding ->

val parameters = SignatureParameters(padding)

val id = api.ciphers.saveParameters(parameters)

add(id to parameters)

}

}

}

val signatureParametersId = api.signatures.saveParameters(TestParameters.Empty)

whyoleg · 2025-04-24T19:38:34Z

cryptography-providers-tests/src/commonMain/kotlin/compatibility/AesCmacCompatibilityTest.kt

+        val cipherIterations = when {
+            isStressTest -> 10
+            else         -> 5
+        }
+        val ivIterations = when {
+            isStressTest -> 10
+            else         -> 5
+        }


Should be just:

val dataIterations = when { isStressTest -> 10 else -> 5 }

Support CMAC

8693eb8

NinjaRat84 marked this pull request as draft March 27, 2025 09:51

Henric Lind added 2 commits March 27, 2025 11:08

Update documentation with CMAC

5dfe16f

Added additional CMAC functions

b07eb1d

Updated CMAC to be similar to others (like HMAC)

c784f04

NinjaRat84 force-pushed the cmac branch from 72d2801 to c784f04 Compare April 8, 2025 14:32

Update CMAC calculations for OpenSSL3

a0cb8c7

Updated CMAC to be AES.CMAC instead and using SignatureGenerator and …

e5d1f67

…SignatureVerifier instead

Updated CMAC to be AES.CMAC instead and using SignatureGenerator and …

0b4ee5e

…SignatureVerifier instead

Updated tests for CMAC

f0eda84

NinjaRat84 marked this pull request as ready for review April 17, 2025 06:31

Henric Lind added 2 commits April 17, 2025 08:35

Updated API

0319b19

Updated API

97f74f7

whyoleg requested changes Apr 24, 2025

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Added initial support for CMAC #69

Added initial support for CMAC #69

NinjaRat84 commented Mar 27, 2025

NinjaRat84 commented Mar 27, 2025

whyoleg commented Mar 30, 2025

NinjaRat84 commented Apr 8, 2025

whyoleg commented Apr 11, 2025

NinjaRat84 commented Apr 14, 2025

whyoleg commented Apr 15, 2025

NinjaRat84 commented Apr 17, 2025

whyoleg commented Apr 24, 2025

whyoleg left a comment

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025

whyoleg Apr 24, 2025


		abstract class AesCmacTestvectorsTest(provider: CryptographyProvider) : AlgorithmTest<AES.CMAC>(AES.CMAC, provider) {

		private fun testCase(key: ByteArray, salt: ByteArray, expected: ByteArray) {

Added initial support for CMAC #69

Are you sure you want to change the base?

Added initial support for CMAC #69

Conversation

NinjaRat84 commented Mar 27, 2025

NinjaRat84 commented Mar 27, 2025

whyoleg commented Mar 30, 2025

NinjaRat84 commented Apr 8, 2025

whyoleg commented Apr 11, 2025

NinjaRat84 commented Apr 14, 2025

whyoleg commented Apr 15, 2025

NinjaRat84 commented Apr 17, 2025

whyoleg commented Apr 24, 2025

whyoleg left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment