Context

When users send a CSR (Certificate Signing Request) to POST /api/v1/cert-manager/certificates with literal newlines instead of escaped \n characters, the JSON parser fails before reaching the route handler. This is a common user mistake when copying/pasting CSR content directly into JSON.

Before: Returns a generic 500 Internal Server Error with "Something went wrong" message, which provides no indication of what went wrong.

After: Returns a 400 Bad Request with a helpful message: "Invalid JSON in request body. If you are sending a Certificate Signing Request (CSR), ensure newlines are escaped as \n characters, not literal line breaks."

Example of the issue:

// Invalid - literal newlines break JSON parsing
{ "csr": "-----BEGIN CERTIFICATE REQUEST-----
MIIB..." }

// Valid - newlines escaped
{ "csr": "-----BEGIN CERTIFICATE REQUEST-----\nMIIB..." }

Screenshots

N/A - API-only change

Steps to verify the change

1. Send a POST request to /api/v1/cert-manager/certificates with a properly escaped CSR (newlines as \n) - should work normally (200)
2. Send a POST request with literal newlines in the CSR - should return 400 with the helpful error message:

   {
     "statusCode": 400,
     "message": "Invalid JSON in request body. If you are sending a Certificate Signing Request (CSR), ensure newlines are escaped as \\n characters, not literal line breaks.",
     "error": "BadRequestError"
   }

Type

• Fix
• Feature
• Improvement
• Breaking
• Docs
• Chore

Checklist

• Title follows the conventional commit format: type(scope): short description (scope is optional, e.g., fix: prevent crash on sync or fix(api): handle null response).
• Tested locally
• Updated docs (if needed)
• Read the contributing guide