Test CORS access with cURL

README.md

Test CORS access with cURL

What is it?

This script is a simple tool to test if server allows cross-origin resource sharing (CORS), i.e. if server allows requests from some domain.

Installation

Download script to ~/.local/bin/cors_test.sh

wget -P ~/.local/bin https://gist.githubusercontent.com/vlazic/9807583e155560d2917bebb8ff99cd9f/raw/e22e82e84f38437bd85b6f8aa09bb172eeb8e439/cors_test.sh
chmod +x ~/.local/bin/cors_test.sh

Usage

You can use this script as a standalone tool.

There are two arguments:

1. Origin of request (frontend app)
2. Destination url (server)

cors_test.sh http://localhost https://example.com

License

MIT

cors_test.sh

#!/usr/bin/env bash

# Cross-Origin Resource Sharing (CORS) test script
# this script tests if server ($1) allows access from specific website ($2)
#
# installation:
#     wget -P ~/.local/bin https://gist.githubusercontent.com/vlazic/9807583e155560d2917bebb8ff99cd9f/raw/e22e82e84f38437bd85b6f8aa09bb172eeb8e439/cors_test.sh ; chmod +x ~/.local/bin/cors_test.sh
#
# function expects two arguments:
#  1) origin of request (frontend app)
#  2) destination url (server)
#
# example:
#     ./cors_test.sh http://localhost https://example.com
#
# --verbose :
#     Prints the server response headers.
# --request OPTIONS :
#     Specifies the HTTP method to use for the request.
# --header "Origin: ${1}" :
#     Specifies the origin of the request.
# --header 'Access-Control-Request-Method: GET' :
#     Specifies the method to use for the actual request.
# 2>&1 | grep -i 'Access-Control-Allow-Origin' :
#     grep is used to find the header that indicates whether the server permits cross-origin resource sharing with resource

if curl \
    --verbose \
    --request OPTIONS \
    "$2" \
    --header "Origin: ${1}" \
    --header 'Access-Control-Request-Method: GET' 2>&1 |
    grep -qi 'Access-Control-Allow-Origin'; then
    echo "👍 ${2} allows CORS requests from ${1}"
else
    echo "👎 ${2} does not allow CORS requests from ${1}"
fi