Oauth2.challenge: def of bend-kit-oauth2@0.11.0.1
Import: import bend-kit-oauth2@0.11.0.1/oauth2.bend as Oauth2
Lines 280-282 of bend-kit-oauth2@0.11.0.1/oauth2.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-oauth2@0.11.0.1/oauth2.bend&start_line=280&end_line=282

import Base
import bend-kit-bytes@0.3.3.0/bytes.bend as Bytes

# §4.2 S256: BASE64URL(SHA256(ASCII(verifier))).
def challenge(+verifier: String) -> IO(Result<&1, &1, Err, String>):
  challenge.words(Bytes.from_string(verifier))

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=IO
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=bend-kit-bytes@0.3.3.0/bytes.bend&name=from_string
  https://jend.leeeet.dev/definition.txt?path=bend-kit-oauth2@0.11.0.1/oauth2.bend&name=Err
  https://jend.leeeet.dev/definition.txt?path=bend-kit-oauth2@0.11.0.1/oauth2.bend&name=challenge.words