fix: handle wechat message url verification

docs/【技术方案】微信虚拟支付接入-2026-05-26.md

@@ -43,8 +43,8 @@ WECHAT_MINI_PROGRAM_VIRTUAL_PAYMENT_ENV=0
 - 泥点属于微信虚拟支付代币（coin），`short_series_coin` 的 `buyQuantity` 必须使用当前泥点商品的 `points_amount`；例如 60 泥点商品应传 `buyQuantity: 60`。
 - 会员直购 `signData` 额外包含 `productId` 和 `goodsPrice`；`goodsPrice` 使用后端商品配置价，和微信后台道具价格校验保持一致。
 - 微信小程序“开发者服务器接收消息推送”必须配置为安全模式，数据格式选 JSON，URL 统一指向 `/api/profile/recharge/wechat/virtual-notify`。
-- `WECHAT_MINIPROGRAM_MESSAGE_TOKEN` 和 `WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY` 由环境变量注入；后端会先校验 `signature/msg_signature`，再用 `EncodingAESKey` 解密 `Encrypt`，然后按虚拟支付事件入账。
-- 安全模式下，GET 验证会直接返回解密后的 `echostr`；POST 推送会先解密再解析 `xpay_goods_deliver_notify` / `xpay_coin_pay_notify`。
+- `WECHAT_MINIPROGRAM_MESSAGE_TOKEN` 和 `WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY` 由环境变量注入；GET URL 验证按官方规则用 `Token/timestamp/nonce` 校验 `signature` 并原样返回 `echostr`，POST 安全模式推送再校验 `msg_signature`、用 `EncodingAESKey` 解密 `Encrypt`，然后按虚拟支付事件入账。
+- 安全模式下，POST 推送会先解密再解析 `xpay_goods_deliver_notify` / `xpay_coin_pay_notify`；不要把 GET URL 验证里的 `echostr` 当密文解密。
 
 ## 验收命令
 

server-rs/crates/api-server/src/wechat_pay.rs

@@ -901,35 +901,15 @@ pub async fn handle_wechat_virtual_payment_message_push_verify(
         Ok(value) => value,
         Err(error) => return build_wechat_message_push_verify_error_response(error),
     };
-    let signature = query
-        .msg_signature
-        .as_deref()
-        .or(query.signature.as_deref())
-        .map(str::trim)
-        .filter(|value| !value.is_empty())
-        .unwrap_or("");
-    let timestamp = query.timestamp.as_deref().map(str::trim).unwrap_or("");
-    let nonce = query.nonce.as_deref().map(str::trim).unwrap_or("");
-    let echostr = query.echostr.as_deref().map(str::trim).unwrap_or("");
-    if signature.is_empty() || timestamp.is_empty() || nonce.is_empty() || echostr.is_empty() {
-        return build_wechat_message_push_verify_error_response(WechatPayError::InvalidRequest(
-            "微信消息推送校验参数不完整".to_string(),
-        ));
-    }
-    if !verify_wechat_message_push_signature(token, timestamp, nonce, echostr, signature) {
-        return build_wechat_message_push_verify_error_response(WechatPayError::InvalidSignature(
-            "微信消息推送校验签名无效".to_string(),
-        ));
-    }
-
-    match decrypt_wechat_message_push_ciphertext(
+    match resolve_wechat_message_push_verify_response(
+        token,
         aes_key,
-        echostr,
         state
             .config
             .wechat_mini_program_app_id
             .as_deref()
             .or(state.config.wechat_app_id.as_deref()),
+        &query,
     ) {
         Ok(plaintext) => (StatusCode::OK, plaintext).into_response(),
         Err(error) => build_wechat_message_push_verify_error_response(error),
@@ -1139,6 +1119,50 @@ fn build_wechat_message_push_verify_error_response(error: WechatPayError) -> Res
     (StatusCode::BAD_REQUEST, message).into_response()
 }
 
+fn resolve_wechat_message_push_verify_response(
+    token: &str,
+    aes_key: &str,
+    expected_app_id: Option<&str>,
+    query: &WechatMiniProgramMessagePushQuery,
+) -> Result<String, WechatPayError> {
+    let timestamp = query.timestamp.as_deref().map(str::trim).unwrap_or("");
+    let nonce = query.nonce.as_deref().map(str::trim).unwrap_or("");
+    let echostr = query.echostr.as_deref().map(str::trim).unwrap_or("");
+    if timestamp.is_empty() || nonce.is_empty() || echostr.is_empty() {
+        return Err(WechatPayError::InvalidRequest(
+            "微信消息推送校验参数不完整".to_string(),
+        ));
+    }
+    let msg_signature = query
+        .msg_signature
+        .as_deref()
+        .map(str::trim)
+        .filter(|value| !value.is_empty());
+    if let Some(signature) = msg_signature {
+        if !verify_wechat_message_push_signature(token, timestamp, nonce, echostr, signature) {
+            return Err(WechatPayError::InvalidSignature(
+                "微信消息推送 msg_signature 无效".to_string(),
+            ));
+        }
+        return decrypt_wechat_message_push_ciphertext(aes_key, echostr, expected_app_id);
+    }
+
+    let signature = query
+        .signature
+        .as_deref()
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .ok_or_else(|| {
+            WechatPayError::InvalidRequest("微信消息推送校验参数不完整".to_string())
+        })?;
+    if !verify_wechat_message_push_signature(token, timestamp, nonce, "", signature) {
+        return Err(WechatPayError::InvalidSignature(
+            "微信消息推送校验签名无效".to_string(),
+        ));
+    }
+    Ok(echostr.to_string())
+}
+
 fn parse_wechat_mini_program_message_push_payload(
     body: &[u8],
 ) -> Result<WechatMiniProgramEncryptedMessage, WechatPayError> {
@@ -2217,6 +2241,31 @@ mod tests {
         ));
     }
 
+    #[test]
+    fn wechat_message_push_plain_get_verify_returns_echostr() {
+        let token = "AAAAA";
+        let timestamp = "1714036504";
+        let nonce = "1514711492";
+        let echostr = "4375120948345356249";
+        let signature = "f464b24fc39322e44b38aa78f5edd27bd1441696";
+
+        let plaintext = resolve_wechat_message_push_verify_response(
+            token,
+            "unused-aes-key",
+            Some("wx-test-app"),
+            &WechatMiniProgramMessagePushQuery {
+                signature: Some(signature.to_string()),
+                timestamp: Some(timestamp.to_string()),
+                nonce: Some(nonce.to_string()),
+                echostr: Some(echostr.to_string()),
+                msg_signature: None,
+            },
+        )
+        .expect("plain url verification should return echostr");
+
+        assert_eq!(plaintext, echostr);
+    }
+
     #[test]
     fn wechat_message_push_decrypts_safe_mode_ciphertext() {
         let app_id = "wx-test-app";