Add AEAD overhead

tests/quic/helpers/aead.nim

@@ -0,0 +1 @@
+const NGTCP2_FAKE_AEAD_OVERHEAD* = 16

tests/quic/helpers/client.nim

@@ -3,6 +3,7 @@ import ngtcp2
 import ids
 import encrypt
 import decrypt
+import aead
 import hp
 import log
 
@@ -93,3 +94,6 @@ proc setupClient*(path: ptr ngtcp2_path, sourceId: ptr ngtcp2_cid, destinationId
   )
 
   ngtcp2_conn_set_retry_aead(result, addr retryAead, addr aeadContext)
+
+  ngtcp2_conn_set_aead_overhead(result, NGTCP2_FAKE_AEAD_OVERHEAD)
+

tests/quic/helpers/decrypt.nim

@@ -1,4 +1,5 @@
 import ngtcp2
+import aead
 
 proc dummyDecrypt*(dest: ptr uint8,
                    aead: ptr ngtcp2_crypto_aead,
@@ -10,5 +11,6 @@ proc dummyDecrypt*(dest: ptr uint8,
                    ad: ptr uint8,
                    adlen: uint): cint {.cdecl.} =
   echo "DECRYPT"
-  copyMem(dest, ciphertext, ciphertextlen)
+  assert ciphertextlen >= NGTCP2_FAKE_AEAD_OVERHEAD
+  moveMem(dest, ciphertext, ciphertextlen - NGTCP2_FAKE_AEAD_OVERHEAD)
 

tests/quic/helpers/encrypt.nim

@@ -1,4 +1,5 @@
 import ngtcp2
+import aead
 
 proc dummyEncrypt*(dest: ptr uint8,
                    aead: ptr ngtcp2_crypto_aead,
@@ -10,4 +11,6 @@ proc dummyEncrypt*(dest: ptr uint8,
                    ad: ptr uint8,
                    adlen: uint): cint{.cdecl.} =
   echo "ENCRYPT"
+  if plaintextlen.bool and plaintext != dest:
     copyMem(dest, plaintext, plaintextlen)
+  zeroMem(cast[ptr uint8](cast[ByteAddress](dest) + ByteAddress(plaintextlen)), NGTCP2_FAKE_AEAD_OVERHEAD)

tests/quic/helpers/server.nim

@@ -2,6 +2,7 @@ import std/monotimes
 import ngtcp2
 import encrypt
 import decrypt
+import aead
 import hp
 import ids
 import log
@@ -116,4 +117,4 @@ proc setupServer*(path: ptr ngtcp2_path, sourceId: ptr ngtcp2_cid, destinationId
     addr hpContext
   )
 
-  ngtcp2_conn_set_aead_overhead(result, 0)
+  ngtcp2_conn_set_aead_overhead(result, NGTCP2_FAKE_AEAD_OVERHEAD)