web/
auth_keys.rs

1//! Per-user JWT signing/verification for the web layer.
2//!
3//! Tokens are signed with each user's own RSA key (private key in their per-user
4//! DB, public key in the global `users` directory). This module wraps the
5//! `server` key lookups + the `token` codec into mint/verify helpers the auth
6//! handlers call.
7//!
8//! Verification always reads the authoritative public key from the directory —
9//! no public-key cache. A cache would risk accepting tokens signed with a
10//! rotated/revoked key until process restart; correctness wins over saving one
11//! indexed primary-key lookup. The DoS surface of unauthenticated lookups is
12//! addressed by rate-limiting the auth endpoints, not by caching.
13
14use crate::token::{self, TokenDetails, TokenType};
15use uuid::Uuid;
16
17/// Whether auth cookies should carry the `Secure` attribute (sent only over
18/// HTTPS). Defaults to `true`; set `INSECURE_COOKIES=1` for local plain-HTTP
19/// development. Bearer cookies (access/refresh tokens) must be `Secure` in
20/// production so they can't leak over a downgraded HTTP request.
21#[must_use]
22pub fn secure_cookies() -> bool {
23    !matches!(
24        std::env::var("INSECURE_COOKIES").as_deref(),
25        Ok("1") | Ok("true")
26    )
27}
28
29/// Mints a token of `token_type` for `user_id`, signed with that user's
30/// private key.
31pub async fn mint(
32    user_id: Uuid,
33    ttl: i64,
34    token_type: TokenType,
35) -> Result<TokenDetails, MintError> {
36    let private_key = server::auth_keys::private_key_for(user_id)
37        .await
38        .map_err(|_| MintError::KeyUnavailable)?;
39    token::generate_jwt_token(user_id, ttl, &private_key, token_type).map_err(|_| MintError::Sign)
40}
41
42/// Verifies a token of the EXPECTED type against its owner's public key.
43///
44/// Reads the `sub` claim unverified as a routing hint ONLY, fetches that user's
45/// authoritative public key from the directory, re-verifies the signature, and
46/// requires the claimed `token_type` to match `expected` — so an access token
47/// can never be replayed where a refresh token is required (or vice-versa).
48/// Returns `None` for any failure — unknown user, missing key, bad signature,
49/// or wrong type — so callers cannot distinguish failure modes (existence
50/// masking). Always hits the DB for the current key, so a rotated/cleared key
51/// takes effect immediately (no stale-key window).
52pub async fn verify(token: &str, expected: TokenType) -> Option<TokenDetails> {
53    let user_id = token::unverified_user_id(token).ok()?;
54    let public_key = server::auth_keys::public_key_for(user_id).await.ok()??;
55    let details = token::verify_jwt_token(&public_key, token).ok()?;
56    if details.token_type != Some(expected) {
57        return None;
58    }
59    Some(details)
60}
61
62#[derive(Debug)]
63pub enum MintError {
64    /// The user has no stored signing key (a provisioning invariant violation).
65    KeyUnavailable,
66    /// Signing failed (malformed key material).
67    Sign,
68}
69
70impl std::fmt::Display for MintError {
71    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
72        match self {
73            MintError::KeyUnavailable => write!(f, "no signing key available for user"),
74            MintError::Sign => write!(f, "failed to sign token"),
75        }
76    }
77}
web/auth_keys.rs

web/
auth_keys.rs
