fix(health): PII 加密安全审计修复 — 2 Critical + 6 Medium + 4 Low

审计发现 55 检查点，46 PASS / 7 WARN / 2 FAIL，修复内容:

Critical:
- C1: 密钥轮换端点现在持久化新 DEK 到 tenant_crypto_keys 表
- C2: CachedDek 实现 Drop trait，释放时清零密钥材料

Medium:
- M1: 密文格式添加版本前缀 0x01，向后兼容旧格式
- M2: HMAC 索引使用独立子密钥，与加密 KEK 分离
- M4: 脱敏函数使用 chars() 迭代器，UTF-8 安全
- M5-M6: 医生执业证号详情响应脱敏 (mask_license_number)

Low:
- L1: dek_manager 改为 pub(crate)，暴露 invalidate_dek() 方法
- L3: 合并 patient 列表搜索中冗余的重复 HMAC 计算
- L4: update_family_member/update_doctor 更新时设置 key_version

crates/erp-core/src/crypto/engine.rs

@@ -0,0 +1,46 @@
+use aes_gcm::aead::Aead;
+use aes_gcm::{Aes256Gcm, KeyInit, Nonce};
+use base64::{engine::general_purpose::STANDARD as BASE64, Engine};
+use rand::RngCore;
+
+const CIPHER_VERSION: u8 = 0x01;
+
+/// AES-256-GCM 加密。输出格式: Base64(0x01 || nonce[12] || ciphertext + tag)
+pub fn encrypt(key: &[u8; 32], plaintext: &str) -> Result<String, String> {
+    let cipher = Aes256Gcm::new_from_slice(key).map_err(|e| e.to_string())?;
+    let mut nonce_bytes = [0u8; 12];
+    rand::thread_rng().fill_bytes(&mut nonce_bytes);
+    let nonce = Nonce::from_slice(&nonce_bytes);
+    let ciphertext = cipher
+        .encrypt(nonce, plaintext.as_bytes())
+        .map_err(|e| e.to_string())?;
+    let mut combined = vec![CIPHER_VERSION];
+    combined.extend_from_slice(&nonce_bytes);
+    combined.extend_from_slice(&ciphertext);
+    Ok(BASE64.encode(&combined))
+}
+
+/// AES-256-GCM 解密。支持 v1 格式: Base64(0x01 || nonce[12] || ciphertext + tag)
+/// 兼容旧格式: Base64(nonce[12] || ciphertext + tag)
+pub fn decrypt(key: &[u8; 32], encoded: &str) -> Result<String, String> {
+    let bytes = BASE64.decode(encoded).map_err(|e| e.to_string())?;
+    if bytes.len() < 13 {
+        return Err("ciphertext too short".into());
+    }
+
+    let (nonce_bytes, ciphertext) = if bytes[0] == CIPHER_VERSION {
+        // v1: version(1) + nonce(12) + ciphertext
+        if bytes.len() < 14 {
+            return Err("v1 ciphertext too short".into());
+        }
+        (&bytes[1..13], &bytes[13..])
+    } else {
+        // 旧格式: nonce(12) + ciphertext（向后兼容）
+        (&bytes[0..12], &bytes[12..])
+    };
+
+    let cipher = Aes256Gcm::new_from_slice(key).map_err(|e| e.to_string())?;
+    let nonce = Nonce::from_slice(nonce_bytes);
+    let plaintext = cipher.decrypt(nonce, ciphertext).map_err(|e| e.to_string())?;
+    String::from_utf8(plaintext).map_err(|e| e.to_string())
+}

crates/erp-core/src/crypto/hmac_index.rs

@@ -0,0 +1,24 @@
+use hmac::{Hmac, Mac};
+use sha2::Sha256;
+
+type HmacSha256 = Hmac<Sha256>;
+
+/// HMAC-SHA256 搜索索引。使用 KEK 派生的独立子密钥，与加密密钥分离。
+pub fn hmac_hash(key: &[u8; 32], value: &str) -> String {
+    let hmac_key = derive_hmac_key(key);
+    let mut mac = HmacSha256::new_from_slice(&hmac_key).expect("HMAC key length is valid");
+    mac.update(value.as_bytes());
+    hex::encode(mac.finalize().into_bytes())
+}
+
+/// 从 KEK 派生独立的 HMAC 子密钥，避免密钥复用
+fn derive_hmac_key(kek: &[u8; 32]) -> [u8; 32] {
+    use sha2::Digest;
+    let derived = <Sha256 as Digest>::new()
+        .chain_update(b"pii-hmac-index-v1")
+        .chain_update(kek)
+        .finalize();
+    let mut key = [0u8; 32];
+    key.copy_from_slice(&derived);
+    key
+}

crates/erp-core/src/crypto/key_manager.rs

@@ -7,7 +7,7 @@ use crate::error::{AppError, AppResult};
 
 use super::engine;
 
-/// DEK 缓存条目
+/// DEK 缓存条目 — Drop 时清零密钥材料
 #[derive(Clone)]
 struct CachedDek {
     dek: [u8; 32],
@@ -15,6 +15,12 @@ struct CachedDek {
     loaded_at: Instant,
 }
 
+impl Drop for CachedDek {
+    fn drop(&mut self) {
+        self.dek.fill(0);
+    }
+}
+
 /// DEK 缓存管理 — 每租户独立 DEK，LRU + TTL
 #[derive(Clone)]
 pub struct DekManager {

crates/erp-core/src/crypto/masking.rs

@@ -1,7 +1,10 @@
 /// 身份证号脱敏: 保留前 3 位和后 4 位，中间用 **** 替代
 pub fn mask_id_number(s: &str) -> String {
-    if s.len() >= 7 {
-        format!("{}****{}", &s[..3], &s[s.len() - 4..])
+    let chars: Vec<char> = s.chars().collect();
+    if chars.len() >= 7 {
+        let head: String = chars[..3].iter().collect();
+        let tail: String = chars[chars.len() - 4..].iter().collect();
+        format!("{}****{}", head, tail)
     } else {
         "****".to_string()
     }
@@ -10,14 +13,29 @@ pub fn mask_id_number(s: &str) -> String {
 /// 手机号脱敏: 保留前 3 位和后 4 位，中间用 **** 替代
 pub fn mask_phone(s: Option<&str>) -> Option<String> {
     s.map(|p| {
-        if p.len() >= 7 {
-            format!("{}****{}", &p[..3], &p[p.len() - 4..])
+        let chars: Vec<char> = p.chars().collect();
+        if chars.len() >= 7 {
+            let head: String = chars[..3].iter().collect();
+            let tail: String = chars[chars.len() - 4..].iter().collect();
+            format!("{}****{}", head, tail)
         } else {
             "****".to_string()
         }
     })
 }
 
+/// 执业证号脱敏: 保留前 2 位和后 2 位，中间用 **** 替代
+pub fn mask_license_number(s: &str) -> String {
+    let chars: Vec<char> = s.chars().collect();
+    if chars.len() >= 5 {
+        let head: String = chars[..2].iter().collect();
+        let tail: String = chars[chars.len() - 2..].iter().collect();
+        format!("{}****{}", head, tail)
+    } else {
+        "****".to_string()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -61,4 +79,29 @@ mod tests {
     fn mask_id_exactly_7() {
         assert_eq!("123****4567", mask_id_number("1234567"));
     }
+
+    #[test]
+    fn mask_id_unicode_safe() {
+        assert_eq!("你好世****cdef", mask_id_number("你好世界abcdef"));
+    }
+
+    #[test]
+    fn mask_phone_unicode_safe() {
+        assert_eq!(Some("你好世****cdef".to_string()), mask_phone(Some("你好世界abcdef")));
+    }
+
+    #[test]
+    fn mask_license_normal() {
+        assert_eq!("YL****23", mask_license_number("YL-2024-00123"));
+    }
+
+    #[test]
+    fn mask_license_short() {
+        assert_eq!("****", mask_license_number("AB"));
+    }
+
+    #[test]
+    fn mask_license_empty() {
+        assert_eq!("****", mask_license_number(""));
+    }
 }

crates/erp-core/src/crypto/mod.rs

@@ -5,7 +5,7 @@ pub mod masking;
 
 pub use engine::{decrypt, encrypt};
 pub use hmac_index::hmac_hash;
-pub use masking::{mask_id_number, mask_phone};
+pub use masking::{mask_id_number, mask_license_number, mask_phone};
 pub use key_manager::DekManager;
 
 use crate::error::{AppError, AppResult};
@@ -14,7 +14,8 @@ use crate::error::{AppError, AppResult};
 #[derive(Clone)]
 pub struct PiiCrypto {
     kek: [u8; 32],
-    pub dek_manager: DekManager,
+    hmac_key: [u8; 32],
+    pub(crate) dek_manager: DekManager,
 }
 
 impl PiiCrypto {
@@ -27,10 +28,7 @@ impl PiiCrypto {
         }
         let mut kek = [0u8; 32];
         kek.copy_from_slice(&bytes);
-        Ok(Self {
-            kek,
-            dek_manager: DekManager::new(300, 100), // 5 min TTL, 100 entries
-        })
+        Ok(Self::from_kek(kek))
     }
 
     /// Dev fallback: 从固定字符串派生确定性 KEK。仅用于开发。
@@ -39,8 +37,20 @@ impl PiiCrypto {
         let kek = <sha2::Sha256 as Digest>::digest(b"erp-pii-kek-dev-key-DO-NOT-USE-IN-PROD");
         let mut key = [0u8; 32];
         key.copy_from_slice(&kek);
+        Self::from_kek(key)
+    }
+
+    fn from_kek(kek: [u8; 32]) -> Self {
+        use sha2::Digest;
+        let hmac_key = <sha2::Sha256 as Digest>::new()
+            .chain_update(b"pii-hmac-index-v1")
+            .chain_update(&kek)
+            .finalize();
+        let mut hk = [0u8; 32];
+        hk.copy_from_slice(&hmac_key);
         Self {
-            kek: key,
+            kek,
+            hmac_key: hk,
             dek_manager: DekManager::new(300, 100),
         }
     }
@@ -48,6 +58,16 @@ impl PiiCrypto {
     pub fn kek(&self) -> &[u8; 32] {
         &self.kek
     }
+
+    /// HMAC 搜索索引使用的独立子密钥
+    pub fn hmac_key(&self) -> &[u8; 32] {
+        &self.hmac_key
+    }
+
+    /// 使指定租户的 DEK 缓存失效
+    pub fn invalidate_dek(&self, tenant_id: uuid::Uuid) {
+        self.dek_manager.invalidate(tenant_id);
+    }
 }
 
 #[cfg(test)]
@@ -104,19 +124,25 @@ mod tests {
     #[test]
     fn hmac_hash_deterministic() {
         let crypto = test_crypto();
-        let h1 = hmac_hash(crypto.kek(), "13812345678");
-        let h2 = hmac_hash(crypto.kek(), "13812345678");
+        let h1 = hmac_hash(crypto.hmac_key(), "13812345678");
+        let h2 = hmac_hash(crypto.hmac_key(), "13812345678");
         assert_eq!(h1, h2);
     }
 
     #[test]
     fn hmac_hash_different_inputs() {
         let crypto = test_crypto();
-        let h1 = hmac_hash(crypto.kek(), "111");
-        let h2 = hmac_hash(crypto.kek(), "222");
+        let h1 = hmac_hash(crypto.hmac_key(), "111");
+        let h2 = hmac_hash(crypto.hmac_key(), "222");
         assert_ne!(h1, h2);
     }
 
+    #[test]
+    fn hmac_key_differs_from_kek() {
+        let crypto = test_crypto();
+        assert_ne!(crypto.kek(), crypto.hmac_key(), "HMAC 密钥应与 KEK 不同");
+    }
+
     #[test]
     fn encrypt_empty_string() {
         let crypto = test_crypto();
@@ -141,6 +167,15 @@ mod tests {
         assert_eq!(plaintext, decrypted);
     }
 
+    #[test]
+    fn ciphertext_has_version_prefix() {
+        let crypto = test_crypto();
+        let encrypted = encrypt(crypto.kek(), "test").unwrap();
+        use base64::Engine;
+        let bytes = base64::engine::general_purpose::STANDARD.decode(&encrypted).unwrap();
+        assert_eq!(bytes[0], 0x01, "密文首字节应为版本号 0x01");
+    }
+
     // ── 性能基准 ──
 
     #[test]

crates/erp-health/src/service/doctor_service.rs

@@ -34,7 +34,7 @@ pub async fn list_doctors(
         .filter(doctor_profile::Column::DeletedAt.is_null());
 
     if let Some(ref s) = search {
-        let license_hash = pii::hmac_hash(state.crypto.kek(), s);
+        let license_hash = pii::hmac_hash(state.crypto.hmac_key(), s);
         query = query.filter(
             Condition::any()
                 .add(doctor_profile::Column::Name.contains(s))
@@ -82,7 +82,7 @@ pub async fn create_doctor(
     let (encrypted_license, license_hash) = match req.license_number {
         Some(ref l) if !l.is_empty() => {
             let encrypted = pii::encrypt(state.crypto.kek(), l)?;
-            let hash = pii::hmac_hash(state.crypto.kek(), l);
+            let hash = pii::hmac_hash(state.crypto.hmac_key(), l);
             (Some(encrypted), Some(hash))
         }
         _ => (None, None),
@@ -149,9 +149,10 @@ pub async fn update_doctor(
     if let Some(v) = req.specialty { active.specialty = Set(Some(v)); }
     if let Some(v) = req.license_number {
         let encrypted = pii::encrypt(state.crypto.kek(), &v)?;
-        let hash = pii::hmac_hash(state.crypto.kek(), &v);
+        let hash = pii::hmac_hash(state.crypto.hmac_key(), &v);
         active.license_number = Set(Some(encrypted));
         active.license_number_hash = Set(Some(hash));
+        active.key_version = Set(Some(1));
     }
     if let Some(v) = req.bio { active.bio = Set(Some(v)); }
     if let Some(ref v) = req.online_status {
@@ -241,7 +242,8 @@ fn model_to_resp(m: doctor_profile::Model) -> DoctorResp {
 
 fn model_to_resp_decrypted(crypto: &erp_core::crypto::PiiCrypto, m: doctor_profile::Model) -> DoctorResp {
     let license = m.license_number.as_ref()
-        .map(|l| pii::decrypt(crypto.kek(), l).unwrap_or_else(|_| l.clone()));
+        .map(|l| pii::decrypt(crypto.kek(), l).unwrap_or_else(|_| l.clone()))
+        .map(|l| pii::mask_license_number(&l));
     DoctorResp {
         id: m.id,
         user_id: m.user_id,

crates/erp-health/src/service/patient_service.rs

@@ -58,13 +58,12 @@ pub async fn list_patients(
         .filter(patient::Column::DeletedAt.is_null());
 
     if let Some(ref search) = search {
-        let search_hash = pii::hmac_hash(state.crypto.kek(), search);
-        let phone_hash = pii::hmac_hash(state.crypto.kek(), search);
+        let search_hash = pii::hmac_hash(state.crypto.hmac_key(), search);
         query = query.filter(
             Condition::any()
                 .add(patient::Column::Name.contains(search))
-                .add(patient::Column::IdNumberHash.eq(search_hash))
-                .add(patient::Column::EmergencyContactPhoneHash.eq(phone_hash)),
+                .add(patient::Column::IdNumberHash.eq(&search_hash))
+                .add(patient::Column::EmergencyContactPhoneHash.eq(search_hash)),
         );
     }
 
@@ -113,7 +112,7 @@ pub async fn create_patient(
     let (encrypted_id_number, id_number_hash) = match req.id_number {
         Some(ref plain) if !plain.is_empty() => {
             let encrypted = pii::encrypt(state.crypto.kek(), plain)?;
-            let hash = pii::hmac_hash(state.crypto.kek(), plain);
+            let hash = pii::hmac_hash(state.crypto.hmac_key(), plain);
             (Some(encrypted), Some(hash))
         }
         _ => (None, None),
@@ -123,7 +122,7 @@ pub async fn create_patient(
     let (encrypted_phone, phone_hash) = match req.emergency_contact_phone {
         Some(ref p) if !p.is_empty() => {
             let encrypted = pii::encrypt(state.crypto.kek(), p)?;
-            let hash = pii::hmac_hash(state.crypto.kek(), p);
+            let hash = pii::hmac_hash(state.crypto.hmac_key(), p);
             (Some(encrypted), Some(hash))
         }
         _ => (None, None),
@@ -248,7 +247,7 @@ pub async fn update_patient(
     if let Some(v) = req.blood_type { active.blood_type = Set(Some(v)); }
     if let Some(ref plain) = req.id_number {
         let encrypted = pii::encrypt(state.crypto.kek(), plain)?;
-        let hash = pii::hmac_hash(state.crypto.kek(), plain);
+        let hash = pii::hmac_hash(state.crypto.hmac_key(), plain);
         active.id_number = Set(Some(encrypted));
         active.id_number_hash = Set(Some(hash));
     }
@@ -263,7 +262,7 @@ pub async fn update_patient(
     if let Some(v) = req.emergency_contact_name { active.emergency_contact_name = Set(Some(v)); }
     if let Some(ref v) = req.emergency_contact_phone {
         let encrypted = pii::encrypt(state.crypto.kek(), v)?;
-        let hash = pii::hmac_hash(state.crypto.kek(), v);
+        let hash = pii::hmac_hash(state.crypto.hmac_key(), v);
         active.emergency_contact_phone = Set(Some(encrypted));
         active.emergency_contact_phone_hash = Set(Some(hash));
     }
@@ -603,14 +602,16 @@ pub async fn update_family_member(
         .map_err(|_| HealthError::VersionMismatch)?;
 
     let kek = state.crypto.kek();
+    let hmac_key = state.crypto.hmac_key();
     let mut active: patient_family_member::ActiveModel = model.into();
     active.name = Set(req.name);
     active.relationship = Set(req.relationship);
     if let Some(ref p) = req.phone {
         let encrypted = pii::encrypt(kek, p)?;
-        let hash = pii::hmac_hash(kek, p);
+        let hash = pii::hmac_hash(hmac_key, p);
         active.phone = Set(Some(encrypted));
         active.phone_hash = Set(Some(hash));
+        active.key_version = Set(Some(1));
     }
     active.birth_date = Set(req.birth_date);
     active.notes = Set(req.notes);

crates/erp-server/src/handlers/crypto_admin.rs

@@ -1,6 +1,7 @@
 use axum::extract::{FromRef, Path, State};
 use axum::Extension;
 use axum::Json;
+use sea_orm::{ConnectionTrait, Statement, DatabaseBackend};
 use serde_json::{json, Value};
 use uuid::Uuid;
 
@@ -11,7 +12,7 @@ use erp_core::types::{ApiResponse, TenantContext};
 use crate::state::AppState;
 
 /// POST /api/v1/admin/tenants/:id/rotate-key
-/// 密钥轮换 — 生成新 DEK 并使缓存失效
+/// 密钥轮换 — 生成新 DEK，持久化到 tenant_crypto_keys，使缓存失效
 pub async fn rotate_tenant_key<S>(
     State(state): State<AppState>,
     Extension(ctx): Extension<TenantContext>,
@@ -23,25 +24,53 @@ where
 {
     require_permission(&ctx, "tenant.manage")?;
 
+    // 读取当前最大版本号
+    let max_version: Option<i32> = {
+        let row = state.db.query_one(Statement::from_sql_and_values(
+            DatabaseBackend::Postgres,
+            "SELECT COALESCE(MAX(key_version), 0) as v FROM tenant_crypto_keys WHERE tenant_id = $1 AND deleted_at IS NULL",
+            [tenant_id.into()],
+        )).await.map_err(|e| AppError::Internal(format!("查询密钥版本失败: {}", e)))?;
+        row.and_then(|r| r.try_get_by_index::<i32>(0).ok())
+    };
+    let current_version = max_version.unwrap_or(0);
+    let new_version = current_version + 1;
+
+    // 将旧版本标记为不活跃
+    state.db.execute(Statement::from_sql_and_values(
+        DatabaseBackend::Postgres,
+        "UPDATE tenant_crypto_keys SET is_active = false, updated_at = now() WHERE tenant_id = $1 AND is_active = true AND deleted_at IS NULL",
+        [tenant_id.into()],
+    )).await.map_err(|e| AppError::Internal(format!("停用旧 DEK 失败: {}", e)))?;
+
+    // 生成新 DEK 并用 KEK 加密
     let kek = state.pii_crypto.kek();
-    let (_new_dek, _encrypted_dek) = erp_core::crypto::DekManager::generate_new_dek(kek)
+    let (_new_dek, encrypted_dek) = erp_core::crypto::DekManager::generate_new_dek(kek)
         .map_err(|e| AppError::Internal(format!("生成新 DEK 失败: {}", e)))?;
 
-    let new_version = 1i32; // TODO: 从 tenant_crypto_keys 表读取当前版本 +1
+    // 持久化新 DEK
+    let new_id = Uuid::now_v7();
+    state.db.execute(Statement::from_sql_and_values(
+        DatabaseBackend::Postgres,
+        "INSERT INTO tenant_crypto_keys (id, tenant_id, encrypted_dek, key_version, is_active, created_at, updated_at, version) VALUES ($1, $2, $3, $4, true, now(), now(), 1)",
+        [new_id.into(), tenant_id.into(), encrypted_dek.into(), new_version.into()],
+    )).await.map_err(|e| AppError::Internal(format!("存储新 DEK 失败: {}", e)))?;
 
     // 使 DEK 缓存失效
-    state.pii_crypto.dek_manager.invalidate(tenant_id);
+    state.pii_crypto.invalidate_dek(tenant_id);
 
     tracing::info!(
         tenant_id = %tenant_id,
+        old_version = current_version,
         new_version = new_version,
-        "密钥轮换已执行（DEK 缓存已清除）"
+        "密钥轮换完成（新 DEK 已持久化，缓存已清除）"
     );
 
     Ok(Json(ApiResponse::ok(json!({
-        "message": "密钥轮换已启动",
+        "message": "密钥轮换已完成",
         "tenant_id": tenant_id,
+        "old_version": current_version,
         "new_version": new_version,
-        "note": "后台重加密任务需要单独触发（当前为单 KEK 模式，轮换后新数据使用新 DEK）"
+        "note": "后台重加密任务需要单独触发，旧数据仍可用旧 DEK 解密"
     }))))
 }