cURL authentication with mod_auth_openidc and keycloak

Question

I have an authentication server running Keycloak, and a Apache2 webserver with mod_auth_openidc to do OAuth2 authorization.

With browsers, I can successfully intercept access to protected resource to redirect user to Keycloak login page. After successful login, user will be redirected to the resource link.

With Postman, I can also retrieve access token JWT with password grant flow, then use the access token to access protected resource. The cURL code provided by postman indicates that the mod_auth_openidc_session cookie is also required.

Next, I try to do 2-stage cURL command in Linux CLI.

First I retrieve the access token using password grant flow as below. I initiated the cookie engine to capture session cookies given by mod_auth_openidc.

# RETRIEVE ACCESS TOKEN JSON
curl -L -b ./cookie.jar -c ./cookie.jar -d 'client_id=CLIENT_ID' -d 'client_secret=368127b1-1ee0-4f3f-8429-29e9a93daf9a' -d 'username=USERNAME' -d 'password=PASSWORD' -d 'grant_type=password' 'https://AUTH_SERVER:PORT/auth/realms/REALM/protocol/openid-connect/token

# PARSE ACCESS TOKEN
access_token=`echo $response|jq '.access_token'|cut -d\" -f2`

Next, with the access token bearer in header and cookie jar file, I try to access to the protected resource.

curl -b ./cookie.jar -c ./cookie.jar --insecure -L -X GET 'https://RESOURCE_SERVER:PORT/protected_content' --header "'Authorization: Bearer "$access_token"'"

However, I still got redirected to the Keycloak login page, and the session cookie is not recorded in the cookie jar file.

Here is the recorded cookie jar file with sensitive info redacted/replaced.

# Netscape HTTP Cookie File
# https://curl.haxx.se/docs/http-cookies.html
# This file was generated by libcurl! Edit at your own risk.

#HttpOnly_[AUTH_SERVER]     FALSE   /auth/realms/master/    TRUE    0       KC_RESTART      eyJhbGciOiJIUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICI2Y2ZiNjYwOC1kMTlhLTQwZGUtOWJiYS04NzcxOTkzZTIwMWUifQ.eyJjaWQi[REDACTED]4aHhkVDBGZmhBZEVTSm8iLCJub25jZSI6IndTYXNYOWhGeGIxd1hKakNrS2FLMXVadVRGX3ZOZzRGVUZnMTJyYXFWbVkifX0.53645krpwlFnJ09cHAcZhNCci-DhGigu4soN5CVsZQ0
#HttpOnly_[AUTH_SERVER]     FALSE   /auth/realms/master/    TRUE    0       AUTH_SESSION_ID_LEGACY  6a23b139-05ba-4d22-b9e3-9ae857074814.[AUTH_SERVER]
#HttpOnly_[AUTH_SERVER]     FALSE   /auth/realms/master/    TRUE    0       AUTH_SESSION_ID 6a23b139-05ba-4d22-b9e3-9ae857074814.[AUTH_SERVER]
#HttpOnly_[RESOURCE_SERVER]     FALSE   /       TRUE    0       mod_auth_openidc_state_XGEq0YKJAwSt8hxdT0FfhAdESJo      NVc9Mk1FmN[REDACTED]lydKVtOw0iL-Y9iZMjzcUinutFPn74rmVvI_ERV3C8Wn1Euio8pID0jEAmu9NEfY_MEeuzOzqe6w7I20HZUNQHX0uh_vXR8

Can anyone tell me what I did wrong in the 2-stage cURL authentication/authorization process?

Answer 1

You have single quotes inside double quotes when setting Authorization header. This means instead of expect Authorization: Bearer token server is getting 'Authorization: Bearer token' . You can check the contents of your headers by using verbose -v option.

Following command should work as expected:

curl --header "Authorization: Bearer $access_token" -b ./cookie.jar -c ./cookie.jar --insecure -L -X GET https://RESOURCE_SERVER:PORT/protected_content' 

Optionally, if you need double qoutes around token use following:

--header "Authorization: Bearer \"$access_token\""

Side note: In order not to overwrite existing cookies in cookie.jar , use different file name to store cookies from the request to authorized file.