f47c087646
Group B — auth-crate security hardening (post-audit Sonnet test-retest 2026-05-02).
kei-auth-apple:
- jwt.rs: full ES256 JWKS signature verification (jsonwebtoken crate);
validates iss == https://appleid.apple.com, aud == client_id, exp, iat;
decode_id_token_unverified is now cfg(test)-only.
Module docstring promised this since v0.1 — now actually implemented.
- claims.rs (new): IdTokenClaims + AudClaim extracted from jwt.rs.
- error.rs: JwtVerify, JwtDecode, MissingClaim variants.
- client.rs: client_secret_jwt: SecretString (was String); exchange_code accepts
code_verifier: Option<&str> for PKCE.
- provider.rs: verify() does CSRF expected_state ConstantTimeEq + JWT verification;
build_auth_url accepts state + verifier and emits PKCE code_challenge.
- tests/apple_smoke.rs + helpers/: 6 tests including malformed-JWT + non-Apple OAuth +
400-mapping + provider_verify_csrf_mismatch_rejected.
kei-auth-google:
- pkce.rs (new): pkce_challenge + url_encode (RFC 7636 §B.1 test vector covered).
- client.rs: client_secret: SecretString; exchange_code accepts code_verifier.
- provider.rs: verify() rejects on state mismatch; build_auth_url emits S256 challenge.
- tests/google_smoke.rs: 7 tests including CSRF mismatch.
kei-auth:
- main.rs: resolve_token() supports stdin (-) and KEI_AUTH_TOKEN env. Token positional
arg leaked via /proc/<pid>/cmdline + shell history; same fix that v0.14.1
applied to --key.
- main.rs::key(): hard fail if KEI_AUTH_KEY len < 32 bytes (mirror of magiclink).
- tokens.rs::verify(): query_row(...).optional()? instead of .ok() — DB errors now
propagate instead of being swallowed as "token unknown".
kei-runtime-core:
- secrets.rs (new, 81 LOC): SecretString newtype with redacted Debug + zeroize-on-Drop.
Required by every auth crate that holds secret material.
- traits/auth.rs: AuthChallenge::Password.password is now SecretString;
OAuthCode { state, expected_state }.
- error.rs: CsrfStateMismatch variant.
Test results: 48 passed; 0 failed across kei-auth, kei-auth-apple, kei-auth-google,
kei-auth-magiclink, kei-runtime-core. cargo check --workspace clean.
Findings consensus: Apple JWT unverified + OAuth state CSRF appeared in all 3
audit waves (Wave-1 + Wave-A + Wave-B); PKCE absence + secret-derive-Debug appeared
only in Wave-A retest, would have been missed by single-pass audit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
51 lines
1.6 KiB
Rust
51 lines
1.6 KiB
Rust
// SPDX-License-Identifier: Apache-2.0
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// Copyright 2026 <author org>
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//!
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//! PKCE (RFC 7636) helpers and URL percent-encoder shared by the Google
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//! auth provider.
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use base64::Engine as _;
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use sha2::{Digest, Sha256};
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/// Compute PKCE `code_challenge` = `BASE64URL-no-pad(SHA256(verifier))`.
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///
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/// The `code_verifier` is a high-entropy random string (ASCII unreserved
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/// characters, 43–128 chars). See RFC 7636 §4.1.
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pub fn pkce_challenge(verifier: &str) -> String {
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let hash = Sha256::digest(verifier.as_bytes());
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base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(hash)
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}
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/// Percent-encode a string per RFC 3986 §2.1 (only unreserved chars pass).
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pub(crate) fn url_encode(input: &str) -> String {
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let mut out = String::with_capacity(input.len());
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for b in input.bytes() {
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if b.is_ascii_alphanumeric() || matches!(b, b'-' | b'_' | b'.' | b'~') {
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out.push(b as char);
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} else {
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out.push_str(&format!("%{b:02X}"));
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}
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}
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out
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn url_encode_basics() {
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assert_eq!(url_encode("a b"), "a%20b");
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assert_eq!(url_encode("openid email profile"), "openid%20email%20profile");
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assert_eq!(url_encode("https://x/cb"), "https%3A%2F%2Fx%2Fcb");
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assert_eq!(url_encode("safe-_.~"), "safe-_.~");
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}
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#[test]
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fn pkce_challenge_is_base64url_sha256() {
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// RFC 7636 §B.1 test vector.
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let verifier = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk";
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let challenge = pkce_challenge(verifier);
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assert_eq!(challenge, "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM");
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}
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}
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