esi_openapi/
pkce.rs

1use crate::errors::EsiResult;
2use base64::engine::{general_purpose::URL_SAFE_NO_PAD as base64, Engine};
3use rand::random;
4use sha2::{Digest, Sha256};
5
6/// PKCEVerifier is a base64urlencoded String to send in the body of the token request alongside the
7/// code returned from the ESI and the Client ID
8pub type PkceVerifier = String;
9pub type PkceChallenge = String;
10
11pub struct Pkce {
12    pub challenge: PkceChallenge,
13    pub verifier: PkceVerifier,
14}
15
16pub fn generate() -> EsiResult<Pkce> {
17    let verifier: Vec<u8> = (0..32).map(|_| random()).collect();
18
19    let verifier_base64 = base64url(&verifier);
20
21    // Create SHA256 hash of verifier
22    let mut hasher = Sha256::new();
23    hasher.update(&verifier_base64);
24    let challenge = hasher.finalize();
25
26    // Encode challenge as base64 URL-safe string
27    let challenge_base64 = base64url(&challenge.to_vec());
28    Ok(Pkce {
29        challenge: challenge_base64,
30        verifier: verifier_base64,
31    })
32}
33
34pub fn base64url(verifier: &Vec<u8>) -> String {
35    let mut verifier_out = vec![0; verifier.len() * 4 / 3 + 4];
36    let written_size = base64.encode_slice(verifier, &mut verifier_out).unwrap();
37    verifier_out.truncate(written_size);
38    String::from_utf8(verifier_out).unwrap()
39}
esi_openapi/pkce.rs

esi_openapi/
pkce.rs
