stegasoo/PLAN-4.1.2.md

Stegasoo 4.1.2 Plan

Release Theme

Polish and UX improvements after the 4.1.1 stability release.

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1. Real Progress Bar for Encode/Decode

Status: Planned

Problem: Users see elapsed time but no indication of how far along the operation is. Long DCT encodes on Pi can take 2-3 minutes with no feedback.

Solution: Polling + progress file approach

Backend Changes

1. dct_steganography.py - Write progress during block loop:

   if progress_file and block_num % 50 == 0:
       with open(progress_file, 'w') as f:
           json.dump({"current": block_num, "total": total_blocks, "phase": "embedding"}, f)
   

2. app.py - New endpoints:

   • POST /encode returns job_id, starts subprocess
   • GET /encode/progress/<job_id> returns progress JSON
   • GET /encode/result/<job_id> returns final result when done

3. Subprocess wrapper - Pass progress file path to encode/decode functions

Frontend Changes

1. stegasoo.js - After form submit:

   • Show progress bar (Bootstrap progress component)
   • Poll /encode/progress/{job_id} every 500ms
   • Update bar width and percentage text
   • Show phase (hashing, embedding, encoding, etc.)

2. Templates - Add progress bar markup to encode.html and decode.html

Files to Modify

• src/stegasoo/dct_steganography.py
• frontends/web/app.py
• frontends/web/static/js/stegasoo.js
• frontends/web/templates/encode.html
• frontends/web/templates/decode.html

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2. Granular Decode Error Messages

Status: Planned

Problem: Decode failures show generic "Decryption failed" - users don't know if it's wrong photo, wrong passphrase, wrong PIN, corrupted image, or format mismatch.

Solution: Bubble up specific error types from library to UI

Library Level (src/stegasoo/)

1. Custom exception classes:

   class StegasooError(Exception): pass
   class InvalidMagicBytesError(StegasooError): pass
   class DecryptionError(StegasooError): pass
   class ReedSolomonError(StegasooError): pass
   class PayloadTooLargeError(StegasooError): pass
   class InvalidHeaderError(StegasooError): pass
   class NoDataFoundError(StegasooError): pass
   

2. Raise specific exceptions in decode paths:

   • Magic bytes mismatch → "Not a Stegasoo image or wrong mode (LSB/DCT)"
   • RS decode failure → "Image corrupted beyond repair"
   • AES-GCM auth fail → "Wrong credentials (photo/passphrase/PIN)"
   • Header parse fail → "Invalid or corrupted header"
   • No stego data → "No hidden data found in image"

3. Error codes for programmatic handling:

   class ErrorCode(Enum):
       INVALID_MAGIC = "invalid_magic"
       DECRYPTION_FAILED = "decryption_failed"
       RS_FAILED = "rs_failed"
       # etc.
   

Web UI Level (frontends/web/)

1. app.py - Catch specific exceptions, return error type:

   except InvalidMagicBytesError:
       flash("This doesn't appear to be a Stegasoo image, or mode mismatch", "danger")
   except DecryptionError:
       flash("Wrong credentials - check reference photo, passphrase, and PIN", "warning")
   

2. decode.html - Error-specific help text:

   • Wrong credentials → "Double-check your reference photo matches exactly"
   • Corrupted → "Image may have been re-saved or compressed"
   • Mode mismatch → "Try switching between Auto/DCT/LSB"

Files to Modify

• src/stegasoo/__init__.py (export exceptions)
• src/stegasoo/exceptions.py (new file)
• src/stegasoo/dct_steganography.py
• src/stegasoo/steganography.py (LSB)
• frontends/web/app.py
• frontends/web/templates/decode.html

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3. Mobile-Responsive Polish

Status: Planned

Problem: UI works on mobile but has rough edges - cramped buttons, hard-to-tap targets, awkward layouts on small screens.

Solution: Targeted CSS/layout fixes for mobile breakpoints

Areas to Improve

1. Encode/Decode Forms:

   • Stack image drop zones vertically on mobile (currently side-by-side)
   • Larger touch targets for file inputs
   • Full-width buttons on small screens
   • Passphrase input readable at smaller sizes

2. Navigation:

   • Hamburger menu for mobile navbar (if not already)
   • Sticky header doesn't eat too much screen
   • Easy thumb reach for main actions

3. Results/Output:

   • Download buttons full-width on mobile
   • QR codes sized appropriately
   • Click-to-copy message box works well with touch

4. Drop Zones:

   • Larger tap targets
   • Visual feedback for touch (not just hover)
   • Camera integration hint on mobile ("Tap to take photo or choose file")

Testing Targets

• iPhone SE (small)
• iPhone 14 (medium)
• iPad (tablet)
• Android Chrome

Files to Modify

• frontends/web/static/css/style.css (or new mobile.css)
• frontends/web/templates/encode.html
• frontends/web/templates/decode.html
• frontends/web/templates/base.html (navbar)

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Testing Checklist

• Progress bar works on localhost
• Progress bar works on Pi (slower, more visible)
• Cancellation handling (what if user navigates away?)
• Error states display correctly
• Smoke test passes

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4. Forced First-Login Setup

Status: Planned

Problem: Users can navigate the app without creating an admin account first. Should force password setup before anything else.

Solution: Middleware/decorator that redirects to setup page if no users exist.

Files to Modify

• frontends/web/app.py (add before_request check)
• frontends/web/templates/setup.html (ensure it blocks other nav)

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5. Dropzone UX Fixes

Status: Planned

Problem: Dropzone has some interaction bugs:

• Dropzone doesn't clear properly if first QR image fails
• Can't click on image preview to replace file (have to click surrounding border)

Solution: Fix JS event handling and state management

Files to Modify

• frontends/web/static/js/stegasoo.js
• frontends/web/static/css/style.css (clickable preview)

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6. Smoke Test Benchmarking

Status: Planned

Problem: No way to measure encode/decode performance or track regressions.

Solution: Add timing to smoke tests using hyperfine or time.

Features

• Benchmark encode/decode on test images
• Output timing stats (min/max/avg)
• Optional --benchmark flag for smoke-test.sh
• Compare NVMe vs SD card, overclocked vs stock

Files to Modify

• rpi/smoke-test.sh

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7. Docker Cleanup

Status: Planned

Problem: Docker build context is larger than needed (includes test images, rpi scripts, etc.)

Solution: Update .dockerignore to exclude unnecessary files

Files to Modify

• .dockerignore

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8. Release Validation Script

Status: Planned

Problem: Manual release checklist is error-prone. Need automated validation.

Solution: Script that runs through testable checklist items

Features

• Run pytest
• Build and test Docker image
• SSH to Pi and run smoke test (optional, if PI_IP provided)
• Report pass/fail summary

Files to Create

• scripts/validate-release.sh

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Notes

• Keep 4.1.2 focused - 8 small features
• Don't break DCT compatibility (4.1.1 RS format is stable)
• Test on Pi before release