{"record":{"id":"8fb4b65fc08b12f0","repo":"Hmbown/CodeWhale","slug":"inconsistent-update-file-header","errorCode":null,"errorMessage":"Inconsistent update file header.","messagePattern":"Inconsistent update file header\\.","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"crates/tui/plugins/computer-use/app/updates.mjs","lineNumber":68,"sourceCode":"export function validateReleaseZip(bytes) {\n  const minimum=Math.max(0,bytes.length-65557); let end=-1;\n  for(let i=bytes.length-22;i>=minimum;i--) if(bytes.readUInt32LE(i)===0x06054b50&&i+22+bytes.readUInt16LE(i+20)===bytes.length) { end=i; break; }\n  if(end<0||bytes.readUInt16LE(end+4)||bytes.readUInt16LE(end+6)) throw new Error(\"Invalid update archive.\");\n  const count=bytes.readUInt16LE(end+10); let position=bytes.readUInt32LE(end+16),total=0;\n  if(!count||count>2000||bytes.readUInt16LE(end+8)!==count||position+bytes.readUInt32LE(end+12)!==end) throw new Error(\"Invalid update archive index.\");\n  const seen=new Set();\n  for(let i=0;i<count;i++) {\n    if(position+46>end||bytes.readUInt32LE(position)!==0x02014b50) throw new Error(\"Invalid update entry.\");\n    const flags=bytes.readUInt16LE(position+8),method=bytes.readUInt16LE(position+10),length=bytes.readUInt16LE(position+28),extra=bytes.readUInt16LE(position+30),comment=bytes.readUInt16LE(position+32);\n    const name=bytes.subarray(position+46,position+46+length).toString(\"utf8\");\n    const kind=(bytes.readUInt32LE(position+38)>>>16)&0xf000,offset=bytes.readUInt32LE(position+42),compressed=bytes.readUInt32LE(position+20);\n    const size=bytes.readUInt32LE(position+24); total+=size;\n    if(flags&1||![0,8].includes(method)||![0,0x4000,0x8000].includes(kind)||total>512*1024*1024||position+46+length+extra+comment>end) throw new Error(\"Unsupported update entry.\");\n    if(!name.startsWith(`${APP_NAME}.app/`)||name.includes(\"\\\\\")||name.includes(\":\")||name.includes(\"\\0\")||name.split(\"/\").some(part=>part===\"..\"||part===\".\")||seen.has(name)) throw new Error(\"Unsafe update path.\");\n    seen.add(name);\n    if(offset+30>position||bytes.readUInt32LE(offset)!==0x04034b50) throw new Error(\"Invalid update file header.\");\n    const localLength=bytes.readUInt16LE(offset+26),localExtra=bytes.readUInt16LE(offset+28);\n    if(offset+30+localLength+localExtra+compressed>bytes.readUInt32LE(end+16)||bytes.subarray(offset+30,offset+30+localLength).toString(\"utf8\")!==name) throw new Error(\"Inconsistent update file header.\");\n    if(bytes.readUInt16LE(offset+8)!==method||bytes.readUInt16LE(offset+6)!==flags||(!(flags&8)&&(bytes.readUInt32LE(offset+18)!==compressed||bytes.readUInt32LE(offset+22)!==size))) throw new Error(\"Inconsistent update sizes or compression.\");\n    const start=offset+30+localLength+localExtra;\n    // Header sizes are untrusted. Bound actual expansion before ditto writes\n    // anything, including a compressed payload whose headers understate size.\n    const payload=bytes.subarray(start,start+compressed);\n    let expanded;\n    try { expanded=method===0?payload.length:inflateRawSync(payload,{maxOutputLength:Math.max(size,1)}).length; }\n    catch { throw new Error(\"Invalid or oversized compressed update entry.\"); }\n    if(expanded!==size) throw new Error(\"The update entry size did not match its contents.\");\n    position+=46+length+extra+comment;\n  }\n  if(position!==end) throw new Error(\"Invalid update archive length.\");\n  return count;\n}\n\nexport async function prepareUpdate(update) {\n  if(!update?.available) throw new Error(\"Check for an available update first.\");\n  if(!newerVersion(update.version,APP_VERSION)||update.url!==`${repository}/releases/download/v${update.version}/Codewhale-Computer-Use-${update.version}-macos-universal.zip`||!Number.isSafeInteger(update.size)||update.size<=0||update.size>limit) throw new Error(\"The update identity is invalid.\");","sourceCodeStart":50,"sourceCodeEnd":86,"githubUrl":"https://github.com/Hmbown/CodeWhale/blob/73e0f67d83c59909b571efdfc88c4bc28c309cb1/crates/tui/plugins/computer-use/app/updates.mjs#L50-L86","documentation":"The validator cross-checks each entry's local header against its central-directory record: the local header's name/extra lengths plus the compressed size must stay within the archive (against the central-directory offset recorded in the EOCD), and the name stored in the local header must be byte-identical to the central-directory name. A mismatch means the two directory structures disagree, which breaks the offset math used to slice the compressed payload and indicates a malformed or malicious archive.","triggerScenarios":"A local header whose 30-byte fixed part + nameLength + extraLength + compressedSize exceeds the central-directory start (EOCD offset at end+16), or whose local name differs from the central-directory name — typical of zip files with different local vs central metadata (some writers store different extra fields) or of archives edited after writing.","commonSituations":"A build step rewriting entry names in one directory but not the other; zip tools that prepend data (e.g. self-extracting stubs) shifting offsets; crafted archives where central and local names diverge to smuggle paths; concatenating two zips so EOCD offsets point at the wrong file.","solutions":["Rebuild the archive cleanly with one tool (`ditto -c -k` or Info-ZIP) so central and local headers are written consistently.","Run `unzip -t` on the artifact; if it passes there but fails here, your build pipeline is mutating the zip after creation — find and remove that step.","Re-download and verify the asset's SHA-256 against the release digest.","Do not prepend stubs or strip extra fields from a finished zip; repackage instead."],"exampleFix":null,"handlingStrategy":"validation","validationCode":"const names = execFileSync(\"unzip\", [\"-Z1\", zipPath]).toString();\nif (new Set(names.split(\"\\n\").filter(Boolean)).size !== names.split(\"\\n\").filter(Boolean).length) throw new Error(\"central/local name mismatch risk\");","typeGuard":null,"tryCatchPattern":"try { validateReleaseZip(bytes); } catch (e) { if (e.message === \"Inconsistent update file header.\") throw new Error(\"Local and central headers disagree — repackage with a single zip tool\"); throw e; }","preventionTips":["Avoid pipelines that rewrite names/extra fields in one header only","Don't prepend self-extractor stubs to release zips","Round-trip `zip`/`unzip -t` in CI before upload","Verify asset digest on download"],"tags":["zip","archive-parsing","corrupt-file","update-integrity"],"backgroundTag":"checksum-mismatch","analyzedSha":"73e0f67d83c59909b571efdfc88c4bc28c309cb1","analyzedAt":"2026-09-22T01:30:00.501Z","contentChangedAt":"2026-09-22T01:30:00.501Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}