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error: invalid code verifier
Hi. I'm developing a C++ application that needs to connect to Dropbox. I'm stuck at implementing OAuth. As documentation suggests:
code_challenge String?(min_length=43, max_length=128) Part of the ...
Greg-DB
Dropbox Staff
Dropbox StaffThat code_challenge value does not appear to be correct for that code_verifier value. I tried plugging "2LORVR1BWsWNkUuLISmv28MR44bYCiq39mU5m8QuzKM" into https://tonyxu-io.github.io/pkce-generator/ as the "Code Verifier" and got a "Code Challenge" of "xkyg5O2AFQ7xMW1A4tJEXhBee-7mOjI3Zf5a_GxuKCc".
Also, make sure you're using the "Code Challenge" on the /oauth2/authorize URL, and are passing the "Code Verifier" to /oauth2/token, and not the other way around.
Thanks for fast reply.
How strange! I used this link for sha256 and then copied the output to base64url encoder to check my chode_challange and it was ok. I guess I'm missing something here.
And for the second part of your answer, I'm doing exactly as you said.
- Greg-DB
I confirmed that https://tonyxu-io.github.io/pkce-generator/ generates a correct code challenge that Dropbox accepts, so it sounds like there's something wrong in the process you were using.
It looks like the issue is that the "SHA-256 hash calculator" is presenting the hash with hex encoding, which should not be used in the process of generating the code challenge. The app needs to base64URL-encode the binary value, not the hex-encoded value.
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