fix: token hash mismatch — hash hex string, not raw bytes

Critical auth bug: token creation hashed the raw 32 bytes
(hasher.update(token_bytes)) but authentication hashed the hex-encoded
string (hash_token(candidate) where candidate is the hex string the
user sends). This meant newly created tokens could never authenticate.

Fixed all 4 token creation sites (users, tokens, invitations create,
invitations accept) to use hash_token(&plaintext_token) which hashes
the hex string consistently with the auth lookup path.

Removed now-unused sha2::Digest imports from handlers.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

src/channels/web/handlers/invitations.rs

@@ -5,7 +5,6 @@ use std::sync::Arc;
 use axum::{Json, extract::State, http::StatusCode};
 use rand::RngCore;
 use rand::rngs::OsRng;
-use sha2::{Digest, Sha256};
 use uuid::Uuid;
 
 use crate::channels::web::auth::{AdminUser, AuthenticatedUser};
@@ -37,11 +36,7 @@ pub async fn invitations_create_handler(
     let mut token_bytes = [0u8; 32];
     OsRng.fill_bytes(&mut token_bytes);
     let plaintext_token = hex::encode(token_bytes);
-
-    // SHA-256 hash for storage — plaintext is never persisted.
-    let mut hasher = Sha256::new();
-    hasher.update(token_bytes);
-    let hash: [u8; 32] = hasher.finalize().into();
+    let hash = crate::channels::web::auth::hash_token(&plaintext_token);
 
     let invitation_id = Uuid::new_v4();
     let invitation = InvitationRecord {
@@ -129,15 +124,9 @@ pub async fn invitations_accept_handler(
         .to_string();
 
     // Hash the provided token to look up the invitation.
-    let token_bytes = hex::decode(invite_token).map_err(|_| {
-        (
-            StatusCode::BAD_REQUEST,
-            "Invalid invite token format".to_string(),
-        )
-    })?;
-    let mut hasher = Sha256::new();
-    hasher.update(&token_bytes);
-    let hash: [u8; 32] = hasher.finalize().into();
+    // Hash the plaintext token string (not decoded bytes) — must match
+    // how it was hashed during invitation creation via hash_token().
+    let hash = crate::channels::web::auth::hash_token(invite_token);
 
     // Look up the invitation by hash.
     let invitation = store
@@ -187,10 +176,7 @@ pub async fn invitations_accept_handler(
     let mut api_token_bytes = [0u8; 32];
     OsRng.fill_bytes(&mut api_token_bytes);
     let plaintext_api_token = hex::encode(api_token_bytes);
-
-    let mut api_hasher = Sha256::new();
-    api_hasher.update(api_token_bytes);
-    let api_hash: [u8; 32] = api_hasher.finalize().into();
+    let api_hash = crate::channels::web::auth::hash_token(&plaintext_api_token);
 
     let api_prefix = &plaintext_api_token[..8];
 

src/channels/web/handlers/tokens.rs

@@ -9,7 +9,6 @@ use axum::{
 };
 use rand::RngCore;
 use rand::rngs::OsRng;
-use sha2::{Digest, Sha256};
 use uuid::Uuid;
 
 use crate::channels::web::auth::AuthenticatedUser;
@@ -41,14 +40,12 @@ pub async fn tokens_create_handler(
         expires_in_days.map(|days| chrono::Utc::now() + chrono::Duration::days(days as i64));
 
     // Generate 32 random bytes for the token.
+    // Hash the hex-encoded plaintext (what the user sends as Bearer token),
+    // NOT the raw bytes — must match hash_token() in auth.rs.
     let mut token_bytes = [0u8; 32];
     OsRng.fill_bytes(&mut token_bytes);
     let plaintext_token = hex::encode(token_bytes);
-
-    // SHA-256 hash for storage — plaintext is never persisted.
-    let mut hasher = Sha256::new();
-    hasher.update(token_bytes);
-    let hash: [u8; 32] = hasher.finalize().into();
+    let hash = crate::channels::web::auth::hash_token(&plaintext_token);
 
     // First 8 chars of the hex token as a prefix for identification.
     let token_prefix = &plaintext_token[..8];

src/channels/web/handlers/users.rs

@@ -9,7 +9,6 @@ use axum::{
 };
 use rand::RngCore;
 use rand::rngs::OsRng;
-use sha2::{Digest, Sha256};
 use uuid::Uuid;
 
 use crate::channels::web::auth::{AdminUser, AuthenticatedUser};
@@ -71,12 +70,12 @@ pub async fn users_create_handler(
         .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
 
     // Generate a first API token so the new user can authenticate immediately.
+    // Hash the hex-encoded plaintext (what the user sends as Bearer token),
+    // NOT the raw bytes — must match hash_token() in auth.rs.
     let mut token_bytes = [0u8; 32];
     OsRng.fill_bytes(&mut token_bytes);
     let plaintext_token = hex::encode(token_bytes);
-    let mut hasher = Sha256::new();
-    hasher.update(token_bytes);
-    let token_hash: [u8; 32] = hasher.finalize().into();
+    let token_hash = crate::channels::web::auth::hash_token(&plaintext_token);
     let token_prefix = &plaintext_token[..8];
 
     let _token_record = store