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mk29's avatar
mk29
Explorer | Level 3
5 years ago

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 ...
API
mk29's avatar
mk29
Explorer | Level 3
5 years ago

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's avatar
Greg-DB
Icon for Dropbox Community Moderator rankDropbox Community Moderator
5 years ago

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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