UDP message coalescing causing EVP_DecryptFinal_ex to fail?

[shit-lord]

Describe the bug

Server and client are in the same LAN. Server sends 2.5mb data(the content of msquic.dll) with a single StreamSend call.

With the default UDP_RECV_MAX_COALESCED_SIZE enabled state, EVP_DecryptFinal_ex failed almost always occurs in client side when decrypting every sent and resent packets from the StreamSend. Connection establishing packets are fine.

I noticed that the datagram sizes in quic.etl did not match captured packets using raw socket. For example, an event in etl shows Recv 1 UDP datagrams, 2440 bytes but there is no packet larger than 1500 bytes from the capture. Not sure if this is abnormal though.

Nevertheless, when I turned off UDP_RECV_MAX_COALESCED_SIZE by changing Option = MAX_URO_PAYLOAD_LENGTH; to Option = 0; in SocketCreateUdp, the problem seemed to go away.

Affected OS

• [x] Windows
• [ ] Linux
• [ ] macOS
• [ ] Other (specify below)

Additional OS information

server win11 23h2 client win11 24h2

MsQuic version

main

Steps taken to reproduce bug

1. UDP_RECV_MAX_COALESCED_SIZE=MAX_URO_PAYLOAD_LENGTH
2. server StreamSend 2.5mb
3. client EVP_DecryptFinal_ex failed. SHUTDOWN_INITIATED_BY_TRANSPORT
4. UDP_RECV_MAX_COALESCED_SIZE=0
5. server StreamSend 2.5mb
6. succeed

Expected behavior

the default UDP_RECV_MAX_COALESCED_SIZE causing no error

Actual outcome

EVP_DecryptFinal_ex failed in clientside

Additional details

No response

[nibanks]

Please share any logs you have.

[shit-lord]

quiclog.zip This time I sent a larger file of 11MB. log was generated using official 2.4.7 dll EVP_DecryptFinal_ex failed can be found in receiver.etl

[nibanks]

Sorry, we haven't had time to look at your logs yet. Is this still a problem for you?

[anrossi]

If you're still seeing this issue, please re-open with new logs. Thanks!