fix(v3): fix strict mode TLS 1.3 detection bug#5
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- v3_server.go: isServerHelloSupportTLS13 treated extensionListLength as number of extensions instead of total byte length, causing out-of-bounds reads - v3_client.go: isServerHelloSupportTLS13 was called with buffer[5:] (already stripped TLS record header), but the function expected the full frame including header, causing parsing offset error Fixes: strict mode always fails with TLS 1.3 servers
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Summary
isServerHelloSupportTLS13treatedextensionListLengthas number of extensions instead of total byte length, causing out-of-bounds readsisServerHelloSupportTLS13was called withbuffer[5:](already stripped TLS record header), but the function expected the full frameBug Details
Bug 1: Extension parsing loop (v3_server.go)
extensionListLengthis the total byte length of all extensions, NOT the number of extensions. The original code used it as a loop counter, causing the parser to read far past the actual data.Fix: Track bytes consumed with
extensionsReadand add4 + extensionLengthper iteration.Bug 2: Buffer offset (v3_client.go)
Client called
isServerHelloSupportTLS13(buffer[5:])after stripping the 5-byte TLS record header, but the function internally usessessionIDLengthIndex=43which assumes the full frame is passed.Fix: Pass the full buffer instead of
buffer[5:].Testing
Tested with
cloud.tencent.com:443(confirmed TLS 1.3) + strict mode enabled.5/5 random string echo tests pass.