Android Question JWT for B4A

Luciano Veneziano

Active Member
Licensed User
Longtime User
Hello everyone.
Is there for B4A a library to decode JWT like in image?


1692396576451.png
 
Solution
Ciao Luciano,
the decode is very simple
first, you need to "split" the string with the "." character
then Base64 Decode and......

eyJhbGci0iJIUzI1NiIsInR5cCI6IkpXVCJ9 = {"alg""HS256","typ":"JWT"}

eyJ0b2tlbl90eXBlIjoicmVmcmVzaCIsImV4cCI6M
TY5MjQ4MjQ1MCwiaWF0IjoxNjkyMzk2MDUwLCJq
dGki0iJkZTg20TcyMzEwOWE0MzBmYjI4YjIxODR
hZWNlODY3ZiIsInVzZXJfaWQi0jh9 = {"token_type":"refresh","exp":1692482450,"iat":1692396050,"jti""de86723109a430fb28b2184aece867f","user_id"8}

then with the first and second part of base64 datas, you need to execute a HMAC-SHA-256 and check it

I think that you don't need a library

aeric

Expert
Licensed User
Longtime User
There is a code to check the JWT token expiry inside the B4J-SendTool

Maybe it works.
 
Upvote 1

Luciano Veneziano

Active Member
Licensed User
Longtime User
There is a code to check the JWT token expiry inside the B4J-SendTool

Maybe it works.
Thanks aeric!
 
Upvote 0

sirjo66

Well-Known Member
Licensed User
Longtime User
Ciao Luciano,
the decode is very simple
first, you need to "split" the string with the "." character
then Base64 Decode and......

eyJhbGci0iJIUzI1NiIsInR5cCI6IkpXVCJ9 = {"alg""HS256","typ":"JWT"}

eyJ0b2tlbl90eXBlIjoicmVmcmVzaCIsImV4cCI6M
TY5MjQ4MjQ1MCwiaWF0IjoxNjkyMzk2MDUwLCJq
dGki0iJkZTg20TcyMzEwOWE0MzBmYjI4YjIxODR
hZWNlODY3ZiIsInVzZXJfaWQi0jh9 = {"token_type":"refresh","exp":1692482450,"iat":1692396050,"jti""de86723109a430fb28b2184aece867f","user_id"8}

then with the first and second part of base64 datas, you need to execute a HMAC-SHA-256 and check it

I think that you don't need a library
 
Last edited:
Upvote 0
Solution

Luciano Veneziano

Active Member
Licensed User
Longtime User
Ciao Luciano,
the decode is very simple
first, you need to "split" the string with the "." character
then Base64 Decode and......

eyJhbGci0iJIUzI1NiIsInR5cCI6IkpXVCJ9 = {"alg""HS256","typ":"JWT"}

eyJ0b2tlbl90eXBlIjoicmVmcmVzaCIsImV4cCI6M
TY5MjQ4MjQ1MCwiaWF0IjoxNjkyMzk2MDUwLCJq
dGki0iJkZTg20TcyMzEwOWE0MzBmYjI4YjIxODR
hZWNlODY3ZiIsInVzZXJfaWQi0jh9 = {"token_type":"refresh","exp":1692482450,"iat":1692396050,"jti""de86723109a430fb28b2184aece867f","user_id"8}

then with the first and second part of base64 datas, you need to execute a HMAC-SHA-256 and check it

I think that you don't need a library
Thanks!!!
 
Upvote 0
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