From e1820d0ec83a9812b97ba23c7a7300f26f96b576 Mon Sep 17 00:00:00 2001
From: cc <thavenx@outlook.com>
Date: Wed, 24 Jun 2026 20:57:37 +0800
Subject: [PATCH] feat(auth): issue/verify username-bearing HS256 JWT

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 Server/src/auth.rs       | 110 ++++++++++++++++++++++++++++++++++-----
 Server/src/routes/web.rs |   4 +-
 2 files changed, 99 insertions(+), 15 deletions(-)

diff --git a/Server/src/auth.rs b/Server/src/auth.rs
index dab2995..7d0ff90 100644
--- a/Server/src/auth.rs
+++ b/Server/src/auth.rs
@@ -13,9 +13,10 @@
 //! 口令哈希；若将来要对外网开放，应换 Argon2/bcrypt 这类慢哈希。）
 
 use std::collections::{HashMap, HashSet};
-use std::sync::atomic::{AtomicU64, Ordering};
 use std::time::{SystemTime, UNIX_EPOCH};
 
+use jsonwebtoken::{decode, encode, DecodingKey, EncodingKey, Header, Validation};
+use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 use sqlx::mysql::{MySqlPool, MySqlPoolOptions};
 
@@ -187,19 +188,65 @@ impl UserStore {
     }
 }
 
-/// 签发一个登录 token。
-///
-/// 不引入 `rand`/`uuid`：用「纳秒时间戳 + 进程内单调计数器」拼出唯一输入，
-/// 再 SHA256 成不可预测的 hex。够当登录态标识用；将来要做真正的会话校验，
-/// 应换成签名 token（如 JWT）或服务端会话表。
-pub fn issue_token() -> String {
-    static COUNTER: AtomicU64 = AtomicU64::new(0);
-    let nanos = SystemTime::now()
+/// JWT 载荷：`sub` 为用户名，`exp` 为到期 Unix 秒。
+#[derive(Serialize, Deserialize)]
+struct Claims {
+    sub: String,
+    exp: usize,
+}
+
+/// 签发登录 token：带用户名的 HS256 JWT，30 天过期。密钥取 `JWT_SECRET`。
+pub fn issue_token(username: &str) -> String {
+    let exp = now_secs() + 30 * 24 * 3600;
+    sign(&jwt_secret(), username, exp)
+}
+
+/// 校验 token，成功返回其中的用户名。过期/签名不符/格式错均返回 `None`。
+pub fn verify_token(token: &str) -> Option<String> {
+    verify(&jwt_secret(), token)
+}
+
+/// 用指定密钥签一个 JWT（便于测试，不读环境变量）。
+fn sign(secret: &[u8], username: &str, exp: usize) -> String {
+    let claims = Claims {
+        sub: username.to_string(),
+        exp,
+    };
+    encode(
+        &Header::default(),
+        &claims,
+        &EncodingKey::from_secret(secret),
+    )
+    .unwrap_or_default()
+}
+
+/// 用指定密钥校验 JWT（便于测试）。默认校验 `exp`。
+fn verify(secret: &[u8], token: &str) -> Option<String> {
+    decode::<Claims>(
+        token,
+        &DecodingKey::from_secret(secret),
+        &Validation::default(),
+    )
+    .ok()
+    .map(|data| data.claims.sub)
+}
+
+/// 从 `JWT_SECRET` 取签名密钥；未设置则用内置开发密钥并告警（生产务必设置）。
+fn jwt_secret() -> Vec<u8> {
+    match std::env::var("JWT_SECRET") {
+        Ok(s) if !s.trim().is_empty() => s.into_bytes(),
+        _ => {
+            eprintln!("[auth] 警告：未设置 JWT_SECRET，使用内置开发密钥（生产环境务必设置）");
+            b"dev-insecure-secret-change-me".to_vec()
+        }
+    }
+}
+
+fn now_secs() -> usize {
+    SystemTime::now()
         .duration_since(UNIX_EPOCH)
-        .map(|d| d.as_nanos())
-        .unwrap_or(0);
-    let n = COUNTER.fetch_add(1, Ordering::Relaxed);
-    sha256_hex(&format!("{nanos}-{n}"))
+        .map(|d| d.as_secs())
+        .unwrap_or(0) as usize
 }
 
 /// 计算 SHA256 并返回小写 hex 字符串。
@@ -224,3 +271,40 @@ fn constant_time_eq(a: &[u8], b: &[u8]) -> bool {
     }
     diff == 0
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn jwt_round_trips_username() {
+        let secret = b"test-secret";
+        let token = sign(secret, "cc", far_future());
+        assert_eq!(verify(secret, &token), Some("cc".to_string()));
+    }
+
+    #[test]
+    fn jwt_rejects_wrong_secret() {
+        let token = sign(b"secret-a", "cc", far_future());
+        assert_eq!(verify(b"secret-b", &token), None);
+    }
+
+    #[test]
+    fn jwt_rejects_garbage() {
+        assert_eq!(verify(b"s", "not-a-jwt"), None);
+    }
+
+    #[test]
+    fn jwt_rejects_expired() {
+        let token = sign(b"s", "cc", 1); // 1970 年过期
+        assert_eq!(verify(b"s", &token), None);
+    }
+
+    fn far_future() -> usize {
+        (std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_secs()
+            + 3600) as usize
+    }
+}
diff --git a/Server/src/routes/web.rs b/Server/src/routes/web.rs
index 71004cf..0d89db2 100644
--- a/Server/src/routes/web.rs
+++ b/Server/src/routes/web.rs
@@ -98,8 +98,8 @@ async fn login(
     if state.users.verify(&req.username, &req.password).await {
         Ok(Json(LoginResponse {
             ok: true,
-            username: req.username,
-            token: crate::auth::issue_token(),
+            username: req.username.clone(),
+            token: crate::auth::issue_token(&req.username),
         }))
     } else {
         Err(StatusCode::UNAUTHORIZED)