flowchart TD Start([Start]) --> Init[Initialize File Transfer<br/>Status: Initialized<br/>Schedule purge at TTL<br/>default 30d · max 365d] Init --> Auth{Sender authenticated?} Auth -->|No| Unauth[End: 401 Unauthorized] Auth -->|Yes| UploadPath{Upload method} %% Legacy stream UploadPath -->|Legacy stream| LegacyStart[Status: UploadStarted] LegacyStart --> LegacyBody[Stream body to storage] LegacyBody -->|OK| ProcessingGate LegacyBody -->|Error| FailUpload[Status: Failed<br/>UploadFailed event] %% TUS UploadPath -->|TUS| TusCreate[TUS POST create<br/>Status: UploadStarted<br/>Single or partial Location] TusCreate --> TusKind{Upload shape} TusKind -->|Single file| TusPatch[TUS PATCH chunks<br/>withCredentials + CSRF] TusKind -->|Concatenation| TusPartials[Create partials<br/>Upload-Concat: partial] TusPartials --> TusPartialPatch[PATCH partials in parallel] TusPartialPatch --> TusFinal[POST final<br/>Upload-Concat: final; …] TusFinal --> OnComplete[OnFileComplete<br/>Enqueue finalize / concat] TusPatch --> TusActive{{Active TUS window<br/>Sliding UploadExpiration = 24h<br/>renewed on HEAD / PATCH / progress<br/>Stuck job: Failed after 24h idle<br/>if no activity in last 1h}} TusActive --> AuthGrace{{Auth during long upload<br/>Altinn JWT ~2 min · cookie 60 min sliding<br/>ID-Porten auth ~2h hard cap<br/>Expired bearer/cookie accepted for<br/>this fileTransferId while upload session<br/>active ≤ UploadExpiration}} AuthGrace -->|Client aborts / idle > 24h| TusExpired{{Upload no longer resumable<br/>Incomplete upload expired<br/>Awaiting stuck job}} AuthGrace -->|Upload complete| OnComplete OnComplete --> ConcatQ{Final concat?} ConcatQ -->|Yes| ConcatJob[Hangfire concat chain<br/>May set UploadProcessing early<br/>Retry delay 5s · locks 30m–2h] ConcatQ -->|No| PublishPrep ConcatJob -->|OK| PublishPrep[TusPublishUploadHandler<br/>Finalize staging blob] ConcatJob -->|Error| FailUpload PublishPrep --> ProcessingGate{Checksum or virus scan needed?} ProcessingGate -->|Yes| Proc[Status: UploadProcessing] ProcessingGate -->|No| PubDirect[Status: Published] Proc --> Checksum[Deferred checksum validation] Checksum -->|Mismatch| FailChecksum[Status: Failed<br/>Delete blob] Checksum -->|OK · no scan| PubFromProc[Status: Published] Checksum -->|OK · virus scan| ScanWait[Wait for malware scan result<br/>Altinn3Azure · max scan size 50 GB] ScanWait -->|No threats found| PubFromProc ScanWait -->|Malware / not clean| FailMalware[Status: Failed<br/>Delete storage<br/>Does not set Purged] PubDirect --> Published[Status: Published<br/>Ready for download] PubFromProc --> Published %% Recipient phase Published --> Recip{Recipient actions} Recip -->|GET download| DlStart[Actor: DownloadStarted<br/>Ranged: debounce 5 min] Recip -->|Confirm without download| ConfirmBlocked[400 · DownloadStarted required] DlStart --> AfterDl{Next} AfterDl -->|Confirm download| Confirmed[Actor: DownloadConfirmed] AfterDl -->|More downloads| DlStart Confirmed --> AllCheck{All recipients confirmed?} AllCheck -->|No| WaitOthers[Wait for remaining recipients] WaitOthers --> Recip AllCheck -->|Yes| AllDone[Status: AllConfirmedDownloaded] AllDone --> Grace{Purge after all confirmed?} Grace -->|Yes · default| GraceWait[Wait purge grace<br/>default PT2H · max PT24H] Grace -->|No| HoldUntilTTL[Keep until file TTL] GraceWait --> Purge[Status: Purged<br/>Delete storage · FilePurged event] HoldUntilTTL --> TTL[File TTL reached] TTL --> Purge Published -.->|TTL while published| TTL FailUpload --> EndFail([End: Failed]) FailChecksum --> EndFail FailMalware --> EndFail Unauth --> EndAuth([End]) ConfirmBlocked --> Recip Purge --> EndOk([End: Purged]) %% Stuck monitoring (side path) Stuck([Stuck job every 30 min]) -.->|UploadStarted > 24h<br/>no TUS activity 1h| FailUpload TusExpired -.-> Stuck Stuck -.->|UploadProcessing > 15 min| SlackProc[Slack alert only] Stuck -.->|Initialized but upload started<br/>> 15 min| SlackInit[Slack alert only] %% Styles — success / terminal / wait / error / auth style Start fill:#f9f,stroke:#333,stroke-width:2px style EndOk fill:#f9f,stroke:#333,stroke-width:2px style EndFail fill:#f9f,stroke:#333,stroke-width:2px style EndAuth fill:#f9f,stroke:#333,stroke-width:2px style Init fill:#99ff99,stroke:#333,stroke-width:2px style LegacyStart fill:#99ff99,stroke:#333,stroke-width:2px style TusCreate fill:#99ff99,stroke:#333,stroke-width:2px style Proc fill:#99ff99,stroke:#333,stroke-width:2px style Published fill:#99ff99,stroke:#333,stroke-width:2px style PubDirect fill:#99ff99,stroke:#333,stroke-width:2px style PubFromProc fill:#99ff99,stroke:#333,stroke-width:2px style DlStart fill:#99ff99,stroke:#333,stroke-width:2px style Confirmed fill:#99ff99,stroke:#333,stroke-width:2px style AllDone fill:#99ff99,stroke:#333,stroke-width:2px style Purge fill:#87ceeb,stroke:#333,stroke-width:2px style TusActive fill:#99ccff,stroke:#333,stroke-width:2px style AuthGrace fill:#99ccff,stroke:#333,stroke-width:2px style GraceWait fill:#99ccff,stroke:#333,stroke-width:2px style ScanWait fill:#99ccff,stroke:#333,stroke-width:2px style HoldUntilTTL fill:#99ccff,stroke:#333,stroke-width:2px style TusExpired fill:#99ccff,stroke:#333,stroke-width:2px style FailUpload fill:#ff9999,stroke:#333,stroke-width:2px style FailChecksum fill:#ff9999,stroke:#333,stroke-width:2px style FailMalware fill:#ff9999,stroke:#333,stroke-width:2px style Unauth fill:#ff9999,stroke:#333,stroke-width:2px style ConfirmBlocked fill:#ffcc99,stroke:#333,stroke-width:2px style SlackProc fill:#ffcc99,stroke:#333,stroke-width:2px style SlackInit fill:#ffcc99,stroke:#333,stroke-width:2px