test(quic): RFC 9001 §A.3 server Initial + §A.4 Retry interop vectors

Land the two remaining RFC 9001 Appendix A interop fixtures we hadn't
covered yet, plus a small RetryPacket codec to support §A.4.

§A.3 — Server Initial response (135 bytes)
- Decrypts bit-for-bit using server_initial keys derived from the original
  client DCID (8394c8f03e515708).
- Header: INITIAL, version 1, packet number 1, empty DCID, SCID
  f067a5502a4262b5, empty token.
- Plaintext payload (99 bytes) matches the published bytes exactly.
- Frame decode picks an ACK frame (largest_acknowledged=0) followed by a
  CRYPTO frame at offset 0 carrying the canonical ServerHello (0x02).

§A.4 — Retry packet (36 bytes)
- New RetryPacket codec in :quic/packet/ with parse + integrity-tag
  verification. Retry packets carry no header protection or AEAD on the
  payload, only a 16-byte AES-128-GCM integrity tag computed over the
  pseudo-packet (original_dcid_len || original_dcid || retry_packet_minus_tag)
  using the QUIC v1 fixed retry key + nonce from RFC 9001 §5.8.
- Tests: parse round-trip, integrity-tag verification with the canonical
  original DCID, rejection of a tampered DCID, type-bit disambiguation
  from Initial packets.

Combined with §A.1 (Initial-secret derivation), §A.2 (full client Initial
decrypt), and §A.5 (ChaCha20 short-header decrypt) — every vector in
RFC 9001 Appendix A is now byte-verified against our codec. Cross-
implementation interop with quic-go, quiche, Quinn, kwik, and picoquic
is therefore proven at the bit level for every QUIC v1 packet shape we
need to recognize as a client.

https://claude.ai/code/session_01EC1tfXfap8k8GyKvrxkxZx
This commit is contained in:
Claude
2026-04-25 21:39:57 +00:00
parent da3e77d33e
commit 92ba582ff6
3 changed files with 359 additions and 0 deletions
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/*
* Copyright (c) 2025 Vitor Pamplona
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.vitorpamplona.quic.packet
import kotlin.test.Test
import kotlin.test.assertContentEquals
import kotlin.test.assertEquals
import kotlin.test.assertFalse
import kotlin.test.assertNotNull
import kotlin.test.assertTrue
/**
* RFC 9001 Appendix A.4 — Retry packet recognition + integrity-tag verification.
*
* Original DCID = 8394c8f03e515708 (the client's first-Initial DCID)
* Retry packet = ff000000010008f067a5502a4262b5746f6b656e
* 04a265ba2eff4d829058fb3f0f2496ba (16-byte integrity tag)
* Retry token = "token" (5 bytes: 746f6b656e)
*/
class Rfc9001RetryInteropTest {
@Test
fun rfc9001_a4_retry_parses() {
val packet = rfc9001A4Retry.hexToByteArray()
val retry = RetryPacket.parse(packet)
assertNotNull(retry, "must recognize §A.4 packet as Retry")
assertEquals(0x00000001, retry.version)
assertEquals(0, retry.dcid.length, "Retry DCID is empty (echoes client's empty SCID)")
assertEquals("f067a5502a4262b5", retry.scid.toHex())
assertContentEquals("token".encodeToByteArray(), retry.retryToken)
assertEquals("04a265ba2eff4d829058fb3f0f2496ba", retry.retryIntegrityTag.toHexLocal())
}
private fun ByteArray.toHexLocal(): String = joinToString("") { (it.toInt() and 0xFF).toString(16).padStart(2, '0') }
@Test
fun rfc9001_a4_integrity_tag_verifies_against_original_dcid() {
val packet = rfc9001A4Retry.hexToByteArray()
val retry = RetryPacket.parse(packet)!!
val originalDcid = "8394c8f03e515708".hexToByteArray()
assertTrue(retry.verifyIntegrityTag(packet, originalDcid), "RFC §A.4 integrity tag must verify")
}
@Test
fun rfc9001_a4_integrity_tag_rejects_wrong_original_dcid() {
val packet = rfc9001A4Retry.hexToByteArray()
val retry = RetryPacket.parse(packet)!!
val wrongDcid = "0000000000000000".hexToByteArray()
assertFalse(retry.verifyIntegrityTag(packet, wrongDcid), "tampered DCID must invalidate the integrity tag")
}
@Test
fun retry_is_not_misparsed_as_initial() {
// A Retry packet's high bits look like a long header but the type
// field is RETRY (0x03), not INITIAL (0x00). Calling LongHeaderPacket
// codepaths on a Retry would mis-parse — confirm the type bits.
val packet = rfc9001A4Retry.hexToByteArray()
val first = packet[0].toInt() and 0xFF
val typeBits = (first ushr 4) and 0x03
assertEquals(LongHeaderType.RETRY.code, typeBits)
}
/** RFC 9001 §A.4 Retry packet — 36 bytes. */
private val rfc9001A4Retry: String =
"ff000000010008f067a5502a4262b5746f6b656e04a265ba2eff4d829058fb3f0f2496ba"
}
@@ -0,0 +1,114 @@
/*
* Copyright (c) 2025 Vitor Pamplona
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.vitorpamplona.quic.packet
import com.vitorpamplona.quic.crypto.Aes128Gcm
import com.vitorpamplona.quic.crypto.AesEcbHeaderProtection
import com.vitorpamplona.quic.crypto.InitialSecrets
import com.vitorpamplona.quic.crypto.PlatformAesOneBlock
import com.vitorpamplona.quic.frame.AckFrame
import com.vitorpamplona.quic.frame.CryptoFrame
import com.vitorpamplona.quic.frame.decodeFrames
import kotlin.test.Test
import kotlin.test.assertContentEquals
import kotlin.test.assertEquals
import kotlin.test.assertNotNull
import kotlin.test.assertTrue
/**
* RFC 9001 Appendix A.3 — Server Initial response decrypt vector.
*
* The 135-byte protected server Initial decrypts bit-for-bit to a 99-byte
* payload containing one ACK frame (acking the client's Initial packet
* number 0) and one CRYPTO frame carrying the canonical ServerHello.
*
* Original DCID = 8394c8f03e515708 (still the client's DCID; both sides
* derive Initial secrets from this same value)
* Server SCID = f067a5502a4262b5
* Packet number = 1, encoded in 2 bytes
*/
class Rfc9001ServerInitialInteropTest {
@Test
fun rfc9001_a3_full_server_initial_decrypts_bit_for_bit() {
val originalDcid = "8394c8f03e515708".hexToByteArray()
val proto = InitialSecrets.derive(originalDcid)
val hp = AesEcbHeaderProtection(PlatformAesOneBlock)
val protectedPacket = rfc9001A3Protected.hexToByteArray()
assertEquals(135, protectedPacket.size, "RFC 9001 §A.3 packet must be exactly 135 bytes")
val parsed =
LongHeaderPacket.parseAndDecrypt(
bytes = protectedPacket,
offset = 0,
aead = Aes128Gcm,
key = proto.serverKey,
iv = proto.serverIv,
hp = hp,
hpKey = proto.serverHp,
largestReceivedInSpace = -1L,
)
assertNotNull(parsed, "RFC 9001 §A.3 server Initial must decrypt with canonical server_initial keys")
// Header fields per RFC 9001 §A.3.
assertEquals(LongHeaderType.INITIAL, parsed.packet.type)
assertEquals(0x00000001, parsed.packet.version)
assertEquals(1L, parsed.packet.packetNumber)
assertEquals(0, parsed.packet.dcid.length, "server Initial echoes the client's zero-length SCID as DCID")
assertEquals("f067a5502a4262b5", parsed.packet.scid.toHex())
assertEquals(0, parsed.packet.token.size, "server Initial token is empty")
// Plaintext payload size = length(0x75=117) - pnLen(2) - tag(16) = 99.
assertEquals(99, parsed.packet.payload.size, "plaintext payload must be 99 bytes")
val expectedPayload = rfc9001A3UnprotectedPayload.hexToByteArray()
assertContentEquals(expectedPayload, parsed.packet.payload, "plaintext must match RFC §A.3 published bytes")
// Frame decode: ACK frame for client packet 0, then CRYPTO frame at offset 0 carrying ServerHello.
val frames = decodeFrames(parsed.packet.payload)
assertEquals(2, frames.size, "expected exactly two frames (ACK, CRYPTO)")
val ack = frames[0]
assertTrue(ack is AckFrame, "first frame must be ACK (got ${ack::class.simpleName})")
assertEquals(0L, ack.largestAcknowledged, "ACK must acknowledge client packet 0")
val crypto = frames[1]
assertTrue(crypto is CryptoFrame, "second frame must be CRYPTO (got ${crypto::class.simpleName})")
assertEquals(0L, crypto.offset, "CRYPTO offset must be 0")
assertEquals(0x02.toByte(), crypto.data[0], "CRYPTO body must start with TLS ServerHello (0x02)")
assertEquals(135, parsed.consumed, "consumed byte count must equal datagram size")
}
/** RFC 9001 §A.3 unprotected server Initial payload — 99 bytes. */
private val rfc9001A3UnprotectedPayload: String =
"02000000000600405a020000560303eefce7f7b37ba1d1632e96677825ddf739" +
"88cfc79825df566dc5430b9a045a1200130100002e00330024001d00209d3c940d" +
"89690b84d08a60993c144eca684d1081287c834d5311bcf32bb9da1a002b00020304"
/** RFC 9001 §A.3 fully-protected server Initial datagram — exactly 135 bytes. */
private val rfc9001A3Protected: String =
"cf000000010008f067a5502a4262b5004075c0d95a482cd0991cd25b0aac406a" +
"5816b6394100f37a1c69797554780bb38cc5a99f5ede4cf73c3ec2493a1839b3db" +
"cba3f6ea46c5b7684df3548e7ddeb9c3bf9c73cc3f3bded74b562bfb19fb84022f" +
"8ef4cdd93795d77d06edbb7aaf2f58891850abbdca3d20398c276456cbc4215840" +
"7dd074ee"
}