ProtoRune.Atproto.OAuth.PKCE (proto_rune v0.5.1)

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Proof Key for Code Exchange (PKCE) helpers for the AT Protocol OAuth flow.

Implements the S256 code challenge method from RFC 7636 using only :crypto. The code verifier is a high-entropy random string sent to the token endpoint, while the code challenge is its SHA-256 hash sent during the authorization request.

Summary

Functions

challenge(verifier)

Computes the S256 code challenge for a code verifier.

generate()

Generates a {code_verifier, code_challenge} pair.

generate_verifier()

Generates a random code verifier.

Functions

challenge(verifier)

@spec challenge(String.t()) :: String.t()

Computes the S256 code challenge for a code verifier.

Examples

iex> PKCE.challenge("dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk")
"E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM"

generate()

@spec generate() :: {String.t(), String.t()}

Generates a {code_verifier, code_challenge} pair.

generate_verifier()

@spec generate_verifier() :: String.t()

Generates a random code verifier.

Returns a base64url-encoded string (without padding) derived from 32 cryptographically secure random bytes.