On Sun, Mar 16, 2025 at 12:12:08PM +0000, Pranav P wrote:
I am still continuing my search on the issue. It seems that the issue is rising from pylsqpack. When the value field in the packet header for HTTP3 GET request contains long strings there are problems while encoding (Only in s390x). Due to this one of the GET parameters gets jumbled and this results in a bad request. I am not able to see the same issue on ls-qpack though. I will update any new findings.
Yes, I was just going through this today (I hadn't noticed your emails until after I'd spent some time on it) and I found much the same thing. I reduced it to the following more manageable test case:
# amd64 >>> import pylsqpack >>> encoder = pylsqpack.Encoder() >>> decoder = pylsqpack.Decoder(4096, 16) >>> _, frame = encoder.encode(0, [(b':path', b'/dns-query?dns=AAABAAABAAAAAAAAAAABAAABAAAAAAAAA2RucwZnb29nbGUAAAEAAQ')]) >>> decoder.feed_header(0, frame) (b'', [(b':path', b'/dns-query?dns=AAABAAABAAAAAAAAAAABAAABAAAAAAAAA2RucwZnb29nbGUAAAEAAQ')]) # s390x >>> import pylsqpack >>> encoder = pylsqpack.Encoder() >>> decoder = pylsqpack.Decoder(4096, 16) >>> _, frame = encoder.encode(0, [(b':path', b'/dns-query?dns=AAABAAABAAAAAAAAAAABAAABAAAAAAAAA2RucwZnb29nbGUAAAEAAQ')]) >>> decoder.feed_header(0, frame) (b'', [(b':path', b'd/snq-euyrd?snA=AAABAAABAAAAAAAAAAABAAABAAAAAAAAR2cuZwbn92bnUGAAAEAAQ')]) -- Colin Watson (he/him) [cjwat...@debian.org]
