{"record":{"id":"6df39f1522a94636","repo":"odysseus-dev/odysseus","slug":"signature-data-must-be-a-png-image","errorCode":null,"errorMessage":"Signature data must be a PNG image","messagePattern":"Signature data must be a PNG image","errorType":"http","errorClass":"HTTPException","httpStatus":400,"severity":"error","filePath":"routes/signature_routes.py","lineNumber":38,"sourceCode":"\nlogger = logging.getLogger(__name__)\n\n\n_DATA_URL_RE = re.compile(r\"^data:image/png;base64,(?P<data>.+)$\", re.IGNORECASE | re.DOTALL)\n_ANY_IMAGE_DATA_URL_RE = re.compile(r\"^data:image/[^;]+;base64,\", re.IGNORECASE)\n_PNG_MAGIC = b\"\\x89PNG\\r\\n\\x1a\\n\"\n_MAX_SIGNATURE_BYTES = 2 * 1024 * 1024\n_MAX_SIGNATURE_B64 = ((_MAX_SIGNATURE_BYTES + 2) // 3) * 4\n_MAX_SIGNATURE_DIMENSION = 4096\n\n\ndef _normalize_signature_png(raw: str) -> str:\n    raw = (raw or \"\").strip()\n    m = _DATA_URL_RE.match(raw)\n    if m:\n        b64 = m.group(\"data\")\n    elif _ANY_IMAGE_DATA_URL_RE.match(raw):\n        raise HTTPException(400, \"Signature data must be a PNG image\")\n    else:\n        b64 = raw\n    if len(b64) > _MAX_SIGNATURE_B64:\n        raise HTTPException(400, \"Signature PNG is too large\")\n    try:\n        payload = base64.b64decode(b64, validate=True)\n    except Exception:\n        raise HTTPException(400, \"Signature data must be base64-encoded PNG bytes\")\n    if not payload:\n        raise HTTPException(400, \"Signature PNG is empty\")\n    if len(payload) > _MAX_SIGNATURE_BYTES:\n        raise HTTPException(400, \"Signature PNG is too large\")\n    if not payload.startswith(_PNG_MAGIC):\n        raise HTTPException(400, \"Signature data must be a PNG image\")\n    return base64.b64encode(payload).decode(\"ascii\")\n\n\ndef _signature_dimension(value: Optional[int]) -> Optional[int]:","sourceCodeStart":20,"sourceCodeEnd":56,"githubUrl":"https://github.com/odysseus-dev/odysseus/blob/f9235ebbf13f693a6fd29ce70b097f6ec83705bf/routes/signature_routes.py#L20-L56","documentation":"Error \"Signature data must be a PNG image\" thrown in odysseus-dev/odysseus.","triggerScenarios":"Triggered when the corresponding server-side validation or runtime check at the recorded location rejects the request or operation and returns this error message to the caller.","commonSituations":"See trigger scenarios.","solutions":["Draw or upload the signature as a PNG image.","Convert the signature image to PNG and retry."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"f9235ebbf13f693a6fd29ce70b097f6ec83705bf","analyzedAt":"2026-08-14T21:47:48.359Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}