{"record":{"id":"044cad16c65ed8ea","repo":"XTLS/Xray-core","slug":"first-padding-chunk-d-is-shorter-than-header-d","errorCode":null,"errorMessage":"first padding chunk %d is shorter than header %d","messagePattern":"first padding chunk (.+?) is shorter than header (.+?)","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"transport/internet/finalmask/xmc/padding.go","lineNumber":179,"sourceCode":"\t}\n\tif len(chunks) == 0 {\n\t\twriteChunkLength := turn.writeChunkLength\n\t\tif writeChunkLength == 0 {\n\t\t\twriteChunkLength = paddingBufferLength\n\t\t} else if turn.writeChunkMinLength > 0 {\n\t\t\twriteChunkLength, err = randomPaddingTarget(turn.writeChunkMinLength, writeChunkLength)\n\t\t\tif err != nil {\n\t\t\t\treturn fmt.Errorf(\"select padding write chunk length: %w\", err)\n\t\t\t}\n\t\t}\n\t\tchunks = defaultPaddingChunks(recordLength, writeChunkLength)\n\t\tdelays = make([]paddingDelayRange, len(chunks))\n\t\tfor i := 1; i < len(delays); i++ {\n\t\t\tdelays[i] = turn.chunkDelay\n\t\t}\n\t}\n\tif chunks[0] < header.Len() {\n\t\treturn fmt.Errorf(\"first padding chunk %d is shorter than header %d\", chunks[0], header.Len())\n\t}\n\n\tmaxChunkLength := 0\n\tfor _, chunkLength := range chunks {\n\t\tif chunkLength < 1 || chunkLength > maxPaddingChunkLength {\n\t\t\treturn fmt.Errorf(\"invalid padding chunk length: %d\", chunkLength)\n\t\t}\n\t\tmaxChunkLength = max(maxChunkLength, chunkLength)\n\t}\n\tvar buffer []byte\n\tif reusableBuffer == nil {\n\t\tbuffer = make([]byte, maxChunkLength)\n\t} else {\n\t\tif cap(*reusableBuffer) < maxChunkLength {\n\t\t\t*reusableBuffer = make([]byte, maxChunkLength)\n\t\t}\n\t\tbuffer = (*reusableBuffer)[:maxChunkLength]\n\t\tclear(buffer)","sourceCodeStart":161,"sourceCodeEnd":197,"githubUrl":"https://github.com/XTLS/Xray-core/blob/7d214f8b094f75322fa3990f8aadad1c912f24f5/transport/internet/finalmask/xmc/padding.go#L161-L197","documentation":"Error \"first padding chunk %d is shorter than header %d\" thrown in XTLS/Xray-core.","triggerScenarios":"Thrown at transport/internet/finalmask/xmc/padding.go:179 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"7d214f8b094f75322fa3990f8aadad1c912f24f5","analyzedAt":"2026-08-15T14:26:24.325Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}