1package com.peachpasswords.passkeys23import com.peachpasswords.vault.PasskeyData4import com.peachpasswords.vault.VaultEntry5import java.math.BigInteger6import java.security.MessageDigest7import java.security.KeyPairGenerator8import java.security.Signature9import java.security.interfaces.ECPrivateKey10import java.security.interfaces.ECPublicKey11import java.security.spec.ECGenParameterSpec12import java.util.Base6413import kotlinx.serialization.json.Json14import kotlinx.serialization.json.contentOrNull15import kotlinx.serialization.json.jsonObject16import kotlinx.serialization.json.jsonPrimitive17import org.junit.Assert.assertEquals18import org.junit.Assert.assertNotNull19import org.junit.Assert.assertTrue20import org.junit.Test21import org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters22import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters23import org.bouncycastle.crypto.signers.Ed25519Signer2425class PasskeyAssertionTest {26 @Test fun builds_es256_assertion_and_increments_counter() {27 val keyPair = KeyPairGenerator.getInstance("EC").apply {28 initialize(ECGenParameterSpec("secp256r1"))29 }.generateKeyPair()30 val entry = passkeyEntry(keyPair.private as ECPrivateKey)3132 val result = PasskeyAssertion.build(33 entry = entry,34 requestJson = """{"challenge":"Y2hhbGxlbmdl","rpId":"example.com"}""",35 origin = "https://login.example.com",36 )3738 assertNotNull(result)39 result!!40 assertEquals(42, result.nextSignCount)41 val response = Json.parseToJsonElement(result.responseJson).jsonObject42 assertEquals("cred-1", response["id"]?.jsonPrimitive?.contentOrNull)43 val payload = response["response"]!!.jsonObject44 val clientDataBytes = b64Decode(payload["clientDataJSON"]!!.jsonPrimitive.content)45 val clientData = String(clientDataBytes, Charsets.UTF_8)46 val client = Json.parseToJsonElement(clientData).jsonObject47 assertEquals("webauthn.get", client["type"]?.jsonPrimitive?.contentOrNull)48 assertEquals("https://login.example.com", client["origin"]?.jsonPrimitive?.contentOrNull)49 val authData = b64Decode(payload["authenticatorData"]!!.jsonPrimitive.content)50 assertEquals(37, authData.size)51 assertEquals(42, ((authData[33].toInt() and 0xff) shl 24) or ((authData[34].toInt() and 0xff) shl 16) or ((authData[35].toInt() and 0xff) shl 8) or (authData[36].toInt() and 0xff))5253 val verifier = Signature.getInstance("SHA256withECDSA")54 verifier.initVerify(keyPair.public as ECPublicKey)55 verifier.update(authData + MessageDigest.getInstance("SHA-256").digest(clientDataBytes))56 assertTrue(verifier.verify(b64Decode(payload["signature"]!!.jsonPrimitive.content)))57 }5859 @Test fun builds_ed25519_assertion() {60 val seed = ByteArray(32) { (it + 1).toByte() }61 val privateKey = Ed25519PrivateKeyParameters(seed, 0)62 val publicKey = privateKey.generatePublicKey().encoded63 val entry = passkeyEntry(null).copy(64 passkey = passkeyEntry(null).passkey!!.copy(65 privateKeyJwk = """{"kty":"OKP","crv":"Ed25519","d":"${b64(seed)}","x":"${b64(publicKey)}"}""",66 algorithm = -8,67 ),68 )6970 val result = PasskeyAssertion.build(71 entry = entry,72 requestJson = """{"challenge":"Y2hhbGxlbmdl","rpId":"example.com"}""",73 origin = "https://example.com",74 )7576 assertNotNull(result)77 result!!78 val payload = Json.parseToJsonElement(result.responseJson).jsonObject["response"]!!.jsonObject79 val authData = b64Decode(payload["authenticatorData"]!!.jsonPrimitive.content)80 val clientData = b64Decode(payload["clientDataJSON"]!!.jsonPrimitive.content)81 val message = authData + MessageDigest.getInstance("SHA-256").digest(clientData)82 val signature = b64Decode(payload["signature"]!!.jsonPrimitive.content)83 assertEquals(64, signature.size)84 val verifier = Ed25519Signer()85 verifier.init(false, Ed25519PublicKeyParameters(publicKey, 0))86 verifier.update(message, 0, message.size)87 assertTrue(verifier.verifySignature(signature))88 }8990 @Test fun returns_null_for_missing_private_key() {91 val entry = passkeyEntry(null)92 assertEquals(null, PasskeyAssertion.build(entry, """{"challenge":"c","rpId":"example.com"}""", "https://example.com"))93 }9495 private fun passkeyEntry(privateKey: ECPrivateKey?) = VaultEntry(96 id = "entry-1",97 type = "passkey",98 title = "Example",99 passkey = PasskeyData(100 credentialId = "cred-1",101 publicKeyCose = "cose",102 privateKeyJwk = privateKey?.let(::privateJwk),103 rpId = "example.com",104 userHandle = "user-handle",105 userName = "june",106 userDisplayName = "June",107 algorithm = -7,108 signCount = 41,109 ),110 createdAt = 1,111 modifiedAt = 1,112 )113114 private fun privateJwk(key: ECPrivateKey): String =115 """{"kty":"EC","crv":"P-256","d":"${b64(key.s.toFixed32())}"}"""116117 private fun BigInteger.toFixed32(): ByteArray {118 val raw = toByteArray()119 val unsigned = if (raw.size > 1 && raw[0] == 0.toByte()) raw.copyOfRange(1, raw.size) else raw120 return ByteArray(32).also { unsigned.copyInto(it, 32 - unsigned.size) }121 }122123 private fun b64(bytes: ByteArray): String = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes)124 private fun b64Decode(value: String): ByteArray =125 Base64.getUrlDecoder().decode(value.padEnd(((value.length + 3) / 4) * 4, '='))126}