Sergio Gómez 1b692e2298 Fix S256 code challenge method
According to [RFC7636#section-4.3](https://tools.ietf.org/html/rfc7636#section-4.3):

    If the "code_challenge_method" from Section 4.3 was "S256", the
    received "code_verifier" is hashed by SHA-256, base64url-encoded, and
    then compared to the "code_challenge", i.e.:

    BASE64URL-ENCODE(SHA256(ASCII(code_verifier))) == code_challenge

So, the hash must be done before the base64_encode.

The tests are modified to use example data from the
[RFC7636#appendix-B](https://tools.ietf.org/html/rfc7636#appendix-B).
2018-01-18 05:31:44 +01:00
..
2017-12-06 18:24:42 -02:00
2017-12-06 18:24:42 -02:00