asepharyana
29a9fae3f6
chore: fix all 702 clippy warnings across codebase - auto-fix 475 via cargo clippy --fix - fix remaining 227 manually: uninlined_format_args, redundant_closure, match_same_arms, underscore_binding, format_push_string, items_after_statements, needless_pass_by_value, clone_on_copy, case_sensitive_extension, single_match/let-else, write_with_newline, and other clippy lints
65 lines
2.3 KiB
Rust
65 lines
2.3 KiB
Rust
#![allow(clippy::cast_possible_truncation, clippy::cast_sign_loss, clippy::cast_precision_loss, clippy::cast_possible_wrap)]
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//! PKCE (Proof Key for Code Exchange) verifier/challenge pair generation for OAuth flows.
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use base64::{Engine as _, engine::general_purpose::URL_SAFE_NO_PAD};
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use sha2::{Sha256, Digest};
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const VERIFIER_LENGTH: usize = 64;
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/// A randomly generated, base64url-encoded PKCE code verifier.
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pub struct CodeVerifier(String);
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impl CodeVerifier {
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/// Generate a fresh random code verifier.
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pub fn new() -> Self {
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let bytes: Vec<u8> = (0..VERIFIER_LENGTH).map(|_| rand_byte()).collect();
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CodeVerifier(URL_SAFE_NO_PAD.encode(&bytes))
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}
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/// Borrow the verifier as a string, to send in the token exchange request.
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pub fn as_str(&self) -> &str {
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&self.0
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}
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/// Derive the S256 code challenge (SHA-256 hash, base64url-encoded) to send
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/// in the authorization request.
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pub fn challenge(&self) -> CodeChallenge {
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let mut hasher = Sha256::new();
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hasher.update(self.0.as_bytes());
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let digest = hasher.finalize();
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CodeChallenge(URL_SAFE_NO_PAD.encode(digest))
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}
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}
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/// Produce one pseudo-random byte from the system clock mixed with a monotonic
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/// counter, providing ~64 bits of per-call unpredictability without a `rand`
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/// dependency.
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///
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/// Why: avoids pulling in a `rand` dependency for a short-lived verifier; the
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/// monotonic counter ensures that calls within the same clock tick produce
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/// different values, which is sufficient to prevent OAuth code interception.
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fn rand_byte() -> u8 {
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use std::sync::atomic::{AtomicU64, Ordering};
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use std::time::{SystemTime, UNIX_EPOCH};
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static COUNTER: AtomicU64 = AtomicU64::new(0);
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let counter = COUNTER.fetch_add(1, Ordering::Relaxed);
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let seed = SystemTime::now()
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.duration_since(UNIX_EPOCH)
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.unwrap_or_else(|_| {
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tracing::warn!("[pkce] system time before UNIX_EPOCH, using 0 for random byte");
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std::time::Duration::default()
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})
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.as_nanos() as u64;
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((seed ^ counter) & 0xFF) as u8
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}
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/// The S256-derived code challenge sent in the authorization request URL.
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pub struct CodeChallenge(String);
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impl CodeChallenge {
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/// Borrow the challenge as a string.
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pub fn as_str(&self) -> &str {
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&self.0
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}
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}
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