Initial commit - Mold Cost Calculator Application (Security Fixed)

app/errors.py

@@ -0,0 +1,86 @@
+from flask import render_template, jsonify, request, send_from_directory, current_app
+import logging
+import os
+from sqlalchemy.exc import SQLAlchemyError, OperationalError, IntegrityError
+
+logger = logging.getLogger(__name__)
+
+def register_error_handlers(app):
+    @app.errorhandler(400)
+    def handle_400_error(e):
+        logger.error(f'400 error: {str(e)}')
+        if request.path.startswith('/calculate'):
+            return jsonify({'error': 'Invalid request parameters'}), 400
+        return render_template('errors/400.html'), 400
+    
+    @app.errorhandler(403)
+    def handle_403_error(e):
+        logger.error(f'403 error: {str(e)}')
+        if request.path.startswith('/calculate'):
+            return jsonify({'error': 'Access forbidden'}), 403
+        return render_template('errors/403.html'), 403
+    
+    @app.errorhandler(404)
+    def handle_404_error(e):
+        logger.error(f'404 error: {str(e)}')
+        if request.path.startswith('/calculate'):
+            return jsonify({'error': 'Resource not found'}), 404
+        if request.path.startswith('/static/'):
+            app.logger.warning(f'Static file not found: {request.path}')
+            return '', 404
+        return render_template('errors/404.html'), 404
+    
+    @app.errorhandler(500)
+    def handle_500_error(e):
+        logger.error(f'500 error: {str(e)}')
+        app.logger.error(f'Server error: {str(e)}')
+        if request.path.startswith('/calculate'):
+            return jsonify({'error': 'Internal server error'}), 500
+        if request.path.startswith('/static/'):
+            app.logger.error(f'Error serving static file {request.path}: {str(e)}')
+            return '', 404
+        return render_template('errors/500.html'), 500
+    
+    @app.errorhandler(OperationalError)
+    def handle_db_operational_error(error):
+        logger.error(f'Database operational error: {str(error)}', exc_info=True)
+        if request.path.startswith('/api/'):
+            return jsonify({
+                'error': 'Database connection error',
+                'message': 'Unable to connect to the database. Please try again later.'
+            }), 503
+        return render_template('errors/503.html', 
+                             message='Database connection error. Please try again later.'), 503
+
+    @app.errorhandler(IntegrityError)
+    def handle_db_integrity_error(error):
+        logger.error(f'Database integrity error: {str(error)}', exc_info=True)
+        if request.path.startswith('/api/'):
+            return jsonify({
+                'error': 'Database integrity error',
+                'message': 'The operation could not be completed due to data constraints.'
+            }), 409
+        return render_template('errors/409.html', 
+                             message='The operation could not be completed due to data constraints.'), 409
+
+    @app.errorhandler(SQLAlchemyError)
+    def handle_db_error(error):
+        logger.error(f'Database error: {str(error)}', exc_info=True)
+        if request.path.startswith('/api/'):
+            return jsonify({
+                'error': 'Database error',
+                'message': 'An unexpected database error occurred.'
+            }), 500
+        return render_template('errors/500.html', 
+                             message='An unexpected database error occurred.'), 500
+
+    @app.errorhandler(Exception)
+    def handle_unhandled_exception(e):
+        logger.error(f'Unhandled exception: {str(e)}', exc_info=True)
+        app.logger.error(f'Unhandled exception: {str(e)}', exc_info=True)
+        if request.path.startswith('/calculate'):
+            return jsonify({'error': 'Internal server error'}), 500
+        if request.path.startswith('/static/'):
+            app.logger.error(f'Error serving static file {request.path}: {str(e)}')
+            return '', 404
+        return render_template('errors/500.html'), 500