Creation of key with ES512 algorithm expects 64 bytes for public key x and y component length instead of 66 bytes based on P-521 curve

[ryarana]

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FIRST PRE CHECK

• [x] I SOLEMNLY SWEAR THAT I HAVE SEARCHED DOCUMENTATION AND WAS NOT ABLE TO RESOLVE MY ISSUE

What protocol are you implementing?

• [ ] FIDO2 Server
• [ ] CTAP2.0
• [x] CTAP2.1
• [ ] UAF 1.1
• [ ] U2F 1.1
• [ ] U2F 1.2

NOTE: UAF 1.0 certification have been officially sunset. U2F 1.2 only supported version of U2F.

What is your implementation class?

• [x] Security Key / FIDO2 / U2F authenticators
• [ ] Server
• [ ] UAF Client-ASM-Authenticator combo
• [ ] UAF Client
• [ ] UAF ASM-Authenticator

If you are platform authenticator vendor, please email conformance-tools@fidoalliance.org

What is the version of the tool are you using?

1.7.14

What is the OS and the version are you running?

Windows 10 For desktop tools

• [ ] OSX
• [x] Windows
• [ ] Linux

For UAF mobile tools

• [ ] iOS
• [ ] Android

Issue description

Based on WebAuth, https://www.w3.org/TR/webauthn-2/#sctn-alg-identifier Keys with algorithm ES512 (-36) MUST specify P-521 (3) as the crv parameter and MUST NOT use the compressed point form.

While testing using the self-conformance tool v1.7.14 for CTAP 2.1, I encountered the following error: Authr-MakeCred-Resp-1 Test registration response, and “packed” attestation: P-02 AssertionError: For ES512 x coefficient MUST be exactly 64 bytes long!: expected 66 to equal 64 at n.eval (eval at compileCode (js/sandbox.js:25:26), :6482:28)

The authenticator under test returned 66 bytes for the x and y component for ES512 (which is correct for P-521 curve) but the tool expects 64 bytes. In addition, the self-conformance tool code snippet below expects P-521/secp521r1 but its expected length is wrong. _… } else if(COSE_ALG_TO_FIDO_ALG_SHORT[keyStruct[COSE_KEYS.alg]] === ‘secp521r1_ecdsa_sha512_raw’ { assert.strictEqual(keyCBORStruct[COSE_KEYS.x].byteLength, 64, ‘For ES512 x coefficient MUST be exactly 64 bytes long!’); assert.strictEqual(keyCBORStruct[COSEKEYS.y].byteLength, 64, ‘For ES512 y coefficient MUST be exactly 64 bytes long!’); } …

[iirachek]

Sorry for the wait. This issue has been addressed and a fix will be available in the upcoming build. I'll notify you, when the build is published.