Feature: Add External Source (and External Event) Attribute Validation

[pranav-super]

This pull request adds external source/event attribute validation to Aerie.

This means that when an external source is uploaded to AERIE, via endpoints like the CLI or the UI, it is forwarded here, has its formatting checked against a schema, and additionally has the attributes of the source and each of its events checked for validity, before submitting it to the database.

Submission of event/source type schemas for the purpose of later validation is also handled here - the gateway simply checks that they are valid JSON Schema.

A more thorough explanation of the feature can be found in the AERIE PR, here.

To fix the problem, we need to ensure that any error messages sent in the response are properly sanitized or escaped to prevent XSS attacks. The best way to fix this is to use a library like he (HTML entities) to encode the error messages before sending them in the response.

1. Install the he library to handle HTML entity encoding.
2. Import the he library in the file.
3. Use the he.encode function to encode the error messages before sending them in the response.

To fix the problem, we need to ensure that any error messages sent back in the response are properly sanitized to prevent XSS attacks. The best way to achieve this is by using a library that provides HTML escaping functionality. One such library is he (HTML entities), which can be used to escape any potentially dangerous characters in the error message.

1. Install the he library to handle HTML escaping.
2. Import the he library in the file.
3. Use the he.escape function to sanitize the error message before sending it in the response.

To fix the problem, we need to ensure that any user-controlled input included in the error message is properly escaped before being sent in the response. This can be achieved by using a library like he (HTML entities) to encode the error message, preventing any HTML or JavaScript from being executed.

1. Install the he library to handle HTML entity encoding.
2. Import the he library in the file.
3. Use the he.encode function to encode the error message before sending it in the response.

To fix the reflected cross-site scripting vulnerability, we need to sanitize the user input before including it in the response. The best way to achieve this is by using a library that provides HTML escaping functionality. In this case, we can use the escape-html library to escape the source_type_name before including it in the response.

• Import the escape-html library.
• Use the escape function from the escape-html library to sanitize the source_type_name before including it in the response.

To fix the problem, we need to ensure that any error messages sent back in the response are properly sanitized or escaped to prevent XSS attacks. The best way to fix this is to use a library like he (HTML entities) to escape any potentially dangerous characters in the error message before sending it back in the response.

1. Install the he library to handle HTML entity encoding.
2. Import the he library in the file.
3. Use the he.encode function to escape the error message before sending it in the response.

To fix the reflected cross-site scripting vulnerability, we need to ensure that any user-provided data included in the error message is properly sanitized before being sent in the HTTP response. The best way to achieve this is by using a library like escape-html to escape any potentially dangerous characters in the error message.

1. Import the escape-html library at the top of the file.
2. Use the escape function from the escape-html library to sanitize the error message before sending it in the response.

To fix the problem, we need to ensure that the error message is properly sanitized before being sent back in the response. This can be achieved by using a library like he (HTML entities) to escape any HTML meta-characters in the error message. This will prevent any malicious scripts from being executed in the user's browser.

1. Install the he library to handle HTML entity encoding.
2. Import the he library in the file.
3. Use the he.encode function to sanitize the error message before sending it in the response.