Keycloak: ERR_TOO_MANY_REDIRECTS - keycloak

Question

I'm learning Keycloak and I have the following problem.
I have a Java EE application protected through Keycloak (main-app). After logging into keycloak, it accesses another application (app-example, also protected by keycloak) that performs a check and depending on the result returns to main-app or shows an error.
The problem is that app-example redirects to keycloak and keycloak redirects back to app-example. At the end, I get the error: 400 bad request.
In front of keycloak I have an Apache server that acts as a proxy and all connections are via SSL.
First call:
Request URL: https://localhost/app-example
Request Method: GET
Status Code: 302 Found
Remote Address: xxx.xxx.xxx.xxx:443
Referrer Policy: no-referrer-when-downgrade
Connection: Keep-Alive
Content-Length: 0
Date: Mon, 17 Dec 2018 14:09:07 GMT
Keep-Alive: timeout=5, max=96
Location: https://localhost/auth/realms/my-realm/protocol/openid-connect/auth?response_type=code&client_id=appexample&redirect_uri=https%3A%2F%2Flocalhost%2Fapp-example%2F&state=e327185a-6306-4124-b384-215954f51bb7&login=true&scope=openid
Server: Apache/2.4.10 (Debian) mod_jk/1.2.37 OpenSSL/1.0.1t
Set-Cookie: OAuth_Token_Request_State=e327185a-6306-4124-b384-215954f51bb7; Version=1; Secure; HttpOnly
Set-Cookie: JSESSIONID=AxzD3hq5sfv-SJdbSa7HDLJe1lBWC1ExBoy86TdR; path=/app-example
Strict-Transport-Security: max-age=15768000
X-Powered-By: Undertow/1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: es-ES,es;q=0.9
Cache-Control: no-cache
Connection: keep-alive
Cookie: OAuth_Token_Request_State=6f634ef2-cc69-4cb8-bdaa-2d69929b26a8; JSESSIONID=BVzI9MiQB6FYFIUDLyK2dQU_o6OPSCyZB9NQDfXV
Host: localhost
Pragma: no-cache
Referer: https://localhost/main-app/
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36
Second call:
Request URL: https://localhost/auth/realms/my-realm/protocol/openid-connect/auth?response_type=code&client_id=app-example&redirect_uri=https%3A%2F%2Flocalhost%2Fapp-example%2F&state=e327185a-6306-4124-b384-215954f51bb7&login=true&scope=openid
Request Method: GET
Status Code: 302 Found
Remote Address: xxx.xxx.xxx.xxx:443
Referrer Policy: no-referrer-when-downgrade
Cache-Control: no-store, must-revalidate, max-age=0
Connection: Keep-Alive
Content-Length: 0
Date: Mon, 17 Dec 2018 14:09:08 GMT
Keep-Alive: timeout=10
Location: https://localhost/app-example/?state=e327185a-6306-4124-b384-215954f51bb7&session_state=39fc0c37-e60d-42e7-876a-97501753bd6a&code=eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..pDbVJYc-fWIWXhsycldqHA.4nZs2gTZZyNhHRDDF3vjd99vCmM6INRMGk8T-Svcc6U1nxtFu7am_Ck2oTNZKYs0_zRHzgUkU4mzmdfRrTRoN64b4uosAVvZKSx_UDhaOERbaLk4p1wqjAUswc2N-48Vb92XBPr-ihET5WF3mzcGeb2TK6k1_GjaBLdEz4BlO8cYVisp35HNIq1APR7GPh9UbCrJaspLegxrvY5_lM9GPsF3NwWorWFE8G3BeUSQeqF7CwTY4YXJnTPkarbwaYX9.-uqvbrqkLz2JLLjeBl4n3g
P3P: CP="This is not a P3P policy!"
Referrer-Policy: no-referrer-when-downgrade
Server: Apache
Set-Cookie: AUTH_SESSION_ID=39fc0c37-e60d-42e7-876a-97501753bd6a.public:server-public-1; Version=1; Path=/auth/realms/my-realm/; Secure; HttpOnly
Set-Cookie: KC_RESTART=eyJhb....9Y3M; Version=1; Path=/auth/realms/my-realm/; Secure; HttpOnly
Set-Cookie: KEYCLOAK_SESSION=my-realm/f24b7ee7-b32e-4e93-821f-cfbf4708acf4/39fc0c37-e60d-42e7-876a-97501753bd6a; Version=1; Expires=Tue, 18-Dec-2018 00:09:08 GMT; Max-Age=36000; Path=/auth/realms/my-realm/; Secure
Set-Cookie: KEYCLOAK_REMEMBER_ME=; Version=1; Comment=Expiring cookie; Expires=Thu, 01-Jan-1970 00:00:10 GMT; Max-Age=0; Path=/auth/realms/my-realm/; Secure; HttpOnly
Strict-Transport-Security: max-age=15768000
X-Content-Type-Options: nosniff
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: es-ES,es;q=0.9
Cache-Control: no-cache
Connection: keep-alive
Cookie: KEYCLOAK_LOCALE=es; AUTH_SESSION_ID=39fc0c37-e60d-42e7-876a-97501753bd6a.public:server-public-1; KEYCLOAK_SESSION=my-realm/f24b7ee7-b32e-4e93-821f-cfbf4708acf4/39fc0c37-e60d-42e7-876a-97501753bd6a; KEYCLOAK_IDENTITY=eyJhb.....Qgs
Host: localhost
Pragma: no-cache
Referer: https://localhost/main-app/
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36
response_type: code
client_id: appexample
redirect_uri: https://localhost/app-example/
state: e327185a-6306-4124-b384-215954f51bb7
login: true
scope: openid
scope: openid
In the log I observe:
ERROR [io.undertow.request] (default task-73) UT005023: Exception handling request to /main-app/launcher.jsp: org.apache.jasper.JasperException: java.lang.RuntimeException: java.lang.IllegalStateException: UT000139: Exchange already complete
I checked that the json file I got from keycloak and integrated into the application is correct. What's the problem?
cheers

Answer 1

Have you tried clearing your cookies?
In case you're using chrome:
https://support.google.com/chrome/answer/6098869?visit_id=637347644493186330-3872337140&p=rl_error&hl=en-GB&rd=1#redirect
Also using private window will likely help. In my case this was caused by running multiple keycloak instances on localhost over time, which got their cookies mixed up.