Re: [keycloak-user] JWT - Base64 encode/decode issues

Hi everyone, I've been experiencing some random issues when trying to decode the returned idToken from the /protocol/openid-connect/token call. I've found that sometimes the returned idToken is not multiple of 4 and has no padding at the end of the payload section (where mappers are added). So the result is that I'm losing the last 2 characters of the last mapper value. This is one example of a failing token (payload only): > eyJqdGkiOiI4NWNlOGVlZS00N2Y5LTQzOTMtODc4Yi1iMjRiNTA0YWIzMWYiLCJleHAiOjE0NjI3NjY3MjMsIm5iZiI6MCwiaWF0IjoxNDYyNzY2NDIzLCJpc3MiOiJodHRwczovL2lkbS1zMi5zYi5kZXYuc2JldGVudi5jb20vYXV0aC9yZWFsbXMvZWxlY3RyaWNzaGVlcCIsImF1ZCI6ImVzIiwic3ViIjoiMDNlZGMzNzQtYzgyMC00ZDFhLWJhN2YtM2Y0NzlmOGRiMmM4IiwidHlwIjoiSUQiLCJhenAiOiJlcyIsInNlc3Npb25fc3RhdGUiOiIxY2I0Mjk3Zi04ODA3LTQ4ZWUtODBhNS1hMTI5NzRhN2EyYmQiLCJuYW1lIjoiZm5hbWUgbG5hbWUiLCJjdXN0SWQiOiIyNTY3NTgxIiwicHJlZmVycmVkX3VzZXJuYW1lIjoiYW50aHRlc3QiLCJnaXZlbl9uYW1lIjoiZm5hbWUiLCJmYW1pbHlfbmFtZSI6ImxuYW1lIiwiZW1haWwiOiJub2JvZGF5QHNwb3J0c2JldC5jb20uYXUiLCJ0b2tlbiI6Ims4Z3NaKzlsV0dlZUVob212d09ocFk5bXlmeXdOQi9CWE1GWXBEQjErZTdHREJRa0h1R1BSYjJHOE4xYjFRdzJyUHdOVitvTTJzUUlMVVlXYXUvSHFFZ3JWUVhGeGdQd2dTVXl6UUtxaEYydW9KN3JzTFJkSFcza3ZRRy9JMUc1WlFtRnlnRE1va2NUIn0 787 chars (should be 788) if you try to decode it, you'll get: > {"jti":"85ce8eee-47f9-4393-878b-b24b504ab31f","exp":1462766723,"nbf":0,"iat":1462766423,"iss":" > https://idm-s2.sb.dev.sbetenv.com/auth/realms/electricsheep","a... > lname","custId":"2567581","preferred_username":"anthtest","given_name":"fname","family_name":"lname","email":" > noboday(a)sportsbet.com.au > ","token":"k8gsZ+9lWGeeEhomvwOhpY9myfywNB/BXMFYpDB1+e7GDBQkHuGPRb2G8N1b1Qw2rPwNV+oM2sQILUYWau/HqEgrVQXFxgPwgSUyzQKqhF2uoJ7rsLRdHW3kvQG/I1G5ZQmFygDMokcT Which is incomplete. The last two chars (which are *"}*) are missing at the end. So now, if I take the correct complete json and try to encode using another library (as the one used here: https://www.base64encode.org/), I'll get: > 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 > *=* (788 chars, which is ok) Note the equal sign at the end. I'm wondering why Keycloak is not adding those paddings, is that a bug on the lib you are using to encode the payload? As for now, I'm using a workaround that checks for the length of the token and adds the missing padding when needed before try to decode it. while (payload.length() % 4 != 0) payload += "="; That works but it is not ideal. *Should I create a bug on Keycloak's issue tracker?* Thanks in advance. Regards, Fab -- *Fabricio Milone* Developer *Shine Consulting * 30/600 Bourke Street Melbourne VIC 3000 T: 03 8488 9939 M: 04 3200 4006 www.shinetech.com *a* passion for excellence _______________________________________________ keycloak-user mailing list keycloak-user(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/keycloak-user