release: v1.12

fix: HEAD /backup/config 响应 Content-Length 为 0，restic 以为 config 空文件
fix: 添加 RemoteTransport.fileSize() 方法，HEAD 返回实际文件大小
feat: SmbTransport/WebdavTransport 实现 fileSize

README.md

@@ -9,6 +9,7 @@ Android 应用备份与恢复工具，集成 [restic](https://restic.net/) 实
 - **并行备份/恢复** — 备份并发数 3（Semaphore(3)），恢复并发数 2（Semaphore(2)）
 - **存档完整性校验** — 备份后自动 zstd/gzip 校验数据归档
 - **restic 增量去重** — 内建 `librestic.so`（~24MB），支持本地和远端仓库
+- **构建体积优化** — Release APK 仅 11.8 MB（ProGuard/R8 full mode + shrinkResources + BouncyCastle PQC 移除）
 - **远程后端** — WebDAV（如 123 云盘）/ SMB 协议，本地临时仓库 + 自动双向同步 + 进度回调
 - **配置持久化** — 仓库路径、密码、后端参数保存在 `backup_settings.conf`
 - **快照管理** — 初始化仓库、查看统计、按策略清理旧快照（保留 7 天/4 周/3 月）
@@ -98,17 +99,26 @@ ConfigViewModel                 ResticWrapper
 - **文件大小限制** — WebDAV 上传 50MB 上限（防止 ByteArray OOM）
 - **存档完整性校验** — 备份后 zstd/gzip 验证数据归档，校验失败回告
 
-## 编译
+## 构建
+
+### 版本历史
+
+|-|版本|更新内容|
+|-|---:|--------|
+| | v1.3 | 累积快照、AppResult 类型化错误、RootShell Mutex、kotlinx-serialization 迁移 |
+| | v1.4 | APK 体积优化（ProGuard/R8 + shrinkResources + 依赖裁剪），Release APK 从 25 MB 降至 11.8 MB（-52.8%） |
+
+### 编译命令
 
 ```bash
-# Debug APK
+# Debug APK（不压缩，适合开发调试）
 ./gradlew assembleDebug
 
-# Release (需配置签名)
+# Release APK（ProGuard/R8 混淆 + 资源裁剪 + 签名）
 ./gradlew assembleRelease
 ```
 
-`librestic.so` 需放在 `app/src/main/jniLibs/arm64-v8a/` 目录下，在 `build.gradle` 中禁用 `extractNativeLibs` 前的 `useLegacyPackaging`。
+> Release 构建需配置 `release.keystore` 签名文件；`librestic.so` 放在 `app/src/main/jniLibs/arm64-v8a/` 下。
 
 ## 使用说明
 

app/build.gradle

@@ -26,8 +26,8 @@ android {
         applicationId "com.example.androidbackupgui"
         minSdk 24
         targetSdk 34
-        versionCode 4
-        versionName "1.3"
+        versionCode 13
+        versionName "1.12"
     }
     buildFeatures {
         viewBinding true
@@ -37,20 +37,17 @@ android {
     }
     signingConfigs {
         release {
-            def keystoreFile = file("release.keystore")
-            if (keystoreFile.exists()) {
-                storeFile keystoreFile
-                storePassword System.getenv("KEYSTORE_PASSWORD") ?: "android"
-                keyAlias "release"
-                keyPassword System.getenv("KEY_PASSWORD") ?: "android"
-            }
+            storeFile rootProject.file("app/release.keystore")
+            storePassword System.getenv("KEYSTORE_PASSWORD") ?: "android"
+            keyAlias "release"
+            keyPassword System.getenv("KEY_PASSWORD") ?: "android"
+            v1SigningEnabled true
+            v2SigningEnabled true
         }
     }
     buildTypes {
         release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
-            if (file("release.keystore").exists()) {
+            if (rootProject.file("app/release.keystore").exists()) {
                 signingConfig signingConfigs.release
             }
         }
@@ -72,6 +69,13 @@ android {
         jniLibs {
             useLegacyPackaging true
         }
+        resources {
+            excludes += [
+                'org/bouncycastle/pqc/crypto/picnic/lowmcL5.bin.properties',
+                'org/bouncycastle/pqc/crypto/picnic/lowmcL3.bin.properties',
+                'org/bouncycastle/pqc/crypto/picnic/lowmcL1.bin.properties',
+            ]
+        }
     }
 }
 
@@ -89,12 +93,19 @@ dependencies {
     implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.3"
 
     // 方案A: jcifs-ng (SMB) + sardine-android (WebDAV) 替代 rclone serve
-    implementation "eu.agno3.jcifs:jcifs-ng:2.1.10"
-    implementation "com.github.thegrizzlylabs:sardine-android:v0.9"
+    implementation("eu.agno3.jcifs:jcifs-ng:2.1.10") {
+        exclude group: 'org.bouncycastle'
+    }
+    implementation("com.github.thegrizzlylabs:sardine-android:v0.9") {
+        exclude group: 'xpp3'
+        exclude group: 'stax'
+    }
     implementation "org.slf4j:slf4j-android:1.7.36"
 
     // root shell via libsu (Magisk/KernelSU/APatch)
     implementation 'com.github.topjohnwu:libsu:6.0.0'
+    // Full BouncyCastle provider (includes MD4 required by jcifs-ng SMB)
+    implementation 'org.bouncycastle:bcprov-jdk15to18:1.77'
     implementation 'org.nanohttpd:nanohttpd:2.3.1'
     testImplementation "io.kotest:kotest-runner-junit5:5.9.1"
     testImplementation "io.kotest:kotest-assertions-core:5.9.1"

app/proguard-rules.pro

@@ -1 +1,58 @@
-# Add project specific ProGuard rules here.
+# ProGuard/R8 rules for Android Backup GUI
+# ==========================================
+
+# --- kotlinx.serialization ---
+# Keep @SerialName classes and companion serializer fields
+-keepattributes *Annotation*, InnerClasses
+-dontnote kotlinx.serialization.AnnotationsKt
+-keepclassmembers class kotlinx.serialization.json.** {
+    *** Companion;
+}
+-keepclasseswithmembers class kotlinx.serialization.json.** {
+    kotlinx.serialization.KSerializer serializer(...);
+}
+-keep,includedescriptorclasses class com.example.androidbackupgui.**$$serializer { *; }
+-keepclassmembers class com.example.androidbackupgui.** {
+    *** Companion;
+}
+-keepclasseswithmembers class com.example.androidbackupgui.** {
+    kotlinx.serialization.KSerializer serializer(...);
+}
+
+# --- NanoHTTPD ---
+# NanoHTTPD (package fi.iki.elonen despite Maven group org.nanohttpd)
+-keep class fi.iki.elonen.** { *; }
+
+# --- RemoteTransport (WebDAV/SMB) ---
+-keep class com.example.androidbackupgui.backup.RemoteTransport { *; }
+
+# --- Data classes (serialization) ---
+-keep class com.example.androidbackupgui.backup.ResticProgress { *; }
+-keep class com.example.androidbackupgui.backup.BackupSummary { *; }
+-keep class com.example.androidbackupgui.backup.ResticSnapshot { *; }
+-keep class com.example.androidbackupgui.backup.RestoreProgress { *; }
+-keep class com.example.androidbackupgui.backup.BackupConfig { *; }
+-keep class com.example.androidbackupgui.backup.AppError { *; }
+-keep class com.example.androidbackupgui.backup.AppResult { *; }
+
+
+# --- RemoteTransport implementations ---
+-keep class com.example.androidbackupgui.backup.SmbTransport { *; }
+-keep class com.example.androidbackupgui.backup.WebdavTransport { *; }
+
+# --- WifiManager (called from UI, kept for safety) ---
+-keep class com.example.androidbackupgui.backup.WifiManager { *; }
+# --- Keep data models used by kotlinx.serialization ---
+## Keep all model classes that may be referenced via @Serializable
+-keep class com.example.androidbackupgui.model.** { *; }
+
+# --- Keep R classes (referenced by code) ---
+-keep class com.example.androidbackupgui.R { *; }
+
+
+
+# --- jcifs-ng (SMB) — keep class/member names for MD4Provider reflection ---
+-keep class jcifs.util.Crypto { *; }
+-keep class jcifs.smb.NtlmUtil { *; }
+-keep class jcifs.ntlmssp.Type3Message { *; }
+-keep class jcifs.smb.NtlmContext { *; }

app/src/main/java/com/example/androidbackupgui/backup/MD4Provider.kt

@@ -0,0 +1,131 @@
+package com.example.androidbackupgui.backup
+
+import android.util.Log
+import org.bouncycastle.crypto.digests.MD4Digest
+import java.security.MessageDigest
+import java.security.MessageDigestSpi
+import java.security.Provider
+import java.security.Security
+
+/**
+ * Ensures MD4 [MessageDigest] is available for jcifs-ng on Android.
+ *
+ * jcifs-ng 2.1.x obtains MD4 by instantiating [BouncyCastleProvider]
+ * and calling [MessageDigest.getInstance]("MD4", bcProvider).
+ * Android's BouncyCastleProvider class is shadowed by the boot classloader
+ * and lacks MD4.
+ *
+ * Strategy: use reflection to replace `jcifs.util.Crypto.provider`
+ * with a delegating provider that wraps Android's BC and adds MD4.
+ * The MD4 [MessageDigestSpi] implementation comes from [MD4Digest]
+ * in bcprov-jdk15to18 (not shadowed — the class is not in boot CL).
+ */
+object MD4Provider {
+
+    private const val TAG = "MD4Provider"
+    private val registered = java.util.concurrent.atomic.AtomicBoolean(false)
+
+    private val md4Provider: Provider by lazy {
+        val bc = Security.getProvider("BC")
+        Md4DelegatingProvider(bc)
+    }
+
+    fun register() {
+        if (!registered.compareAndSet(false, true)) return
+        try {
+            // 1. Replace cached provider in every jcifs-ng class that has one
+            setProviderField("jcifs.util.Crypto")
+            for (cn in listOf(
+                "jcifs.smb.NtlmUtil",
+                "jcifs.smb.NtlmPasswordAuthenticator",
+                "jcifs.ntlmssp.Type3Message",
+                "jcifs.smb.NtlmContext"
+            )) setProviderField(cn)
+
+            // 2. Verify by checking what Crypto.getProvider() returns
+            try {
+                val cl = Class.forName("jcifs.util.Crypto")
+                val getProv = cl.getDeclaredMethod("getProvider")
+                getProv.isAccessible = true
+                val actual = getProv.invoke(null) as Provider
+                Log.i(TAG, "Crypto.getProvider() => ${actual::class.java.simpleName} (hasMD4=${actual.getService("MessageDigest", "MD4") != null})")
+            } catch (_: Exception) {}
+
+            // 3. Fallback: register a global MD4 provider too
+            try {
+                Security.insertProviderAt(Md4StandaloneProvider(), 1)
+            } catch (_: Exception) {}
+
+        } catch (e: Exception) {
+            Log.e(TAG, "Failed to inject MD4", e)
+        }
+    }
+
+    private fun setProviderField(clsName: String) {
+        try {
+            val cls = Class.forName(clsName)
+            for (f in cls.declaredFields) {
+                if (java.lang.reflect.Modifier.isStatic(f.modifiers) &&
+                    Provider::class.java.isAssignableFrom(f.type)) {
+                    f.isAccessible = true
+                    f.set(null, md4Provider)
+                    Log.i(TAG, "Set $clsName.${f.name} = Md4DelegatingProvider")
+                    return
+                }
+            }
+            Log.i(TAG, "No static Provider field in $clsName")
+        } catch (_: ClassNotFoundException) {
+            Log.i(TAG, "Class not found: $clsName")
+        }
+    }
+
+    // ── MD4 MessageDigestSpi ────────────────────────────────────
+
+    class Md4DigestSpi : MessageDigestSpi() {
+        private val d = MD4Digest()
+        override fun engineGetDigestLength() = d.digestSize
+        override fun engineUpdate(b: Byte) { d.update(b) }
+        override fun engineUpdate(b: ByteArray, o: Int, l: Int) { d.update(b, o, l) }
+        override fun engineDigest(): ByteArray {
+            val r = ByteArray(d.digestSize); d.doFinal(r, 0); return r
+        }
+        override fun engineReset() { d.reset() }
+    }
+
+    // ── Delegating provider ─────────────────────────────────────
+
+    /** A "BC"-named provider that delegates to [bc] except for MD4. */
+    private class Md4DelegatingProvider(
+        private val bc: Provider?
+    ) : Provider("BC", bc?.version ?: 1.0, "BC + MD4") {
+
+        init {
+            // Register MD4 service in the provider's internal service map
+            putService(Service(this, "MessageDigest", "MD4",
+                Md4DigestSpi::class.java.name, null, null))
+        }
+
+        override fun getService(type: String, algorithm: String): Service? {
+            if (type == "MessageDigest" && algorithm.equals("MD4", ignoreCase = true)) {
+                return super.getService(type, algorithm)
+            }
+            return bc?.getService(type, algorithm)
+        }
+
+        override fun getServices(): MutableSet<Service> {
+            val s = (bc?.getServices() ?: emptySet<Service>()).toMutableSet()
+            s.addAll(super.getServices())
+            return s
+        }
+    }
+
+    /** Standalone MD4-only provider registered globally as fallback. */
+    private class Md4StandaloneProvider : Provider("Md4Provider", 1.0, "MD4 only") {
+        override fun getService(type: String, algorithm: String): Service? {
+            if (type == "MessageDigest" && algorithm.equals("MD4", ignoreCase = true)) {
+                return Service(this, type, algorithm, Md4DigestSpi::class.java.name, null, null)
+            }
+            return null
+        }
+    }
+}

app/src/main/java/com/example/androidbackupgui/backup/MissingAlgoProvider.kt

@@ -0,0 +1,137 @@
+package com.example.androidbackupgui.backup
+
+import android.util.Log
+import org.bouncycastle.crypto.digests.MD4Digest
+import org.bouncycastle.crypto.engines.AESEngine
+import org.bouncycastle.crypto.macs.CMac
+import org.bouncycastle.crypto.params.KeyParameter
+import java.security.MessageDigest
+import java.security.MessageDigestSpi
+import java.security.Provider
+import java.security.Security
+import java.security.spec.AlgorithmParameterSpec
+import javax.crypto.MacSpi
+
+/**
+ * Injects missing algorithms (MD4, AESCMAC) into Android's BC provider
+ * for jcifs-ng SMB support.
+ *
+ * jcifs-ng instantiates [BouncyCastleProvider] and requests algorithms
+ * ([MessageDigest]"MD4", [Mac]"AESCMAC") that Android's built-in BC
+ * has removed. The BouncyCastleProvider class is shadowed by the boot
+ * classloader, so we patch `jcifs.util.Crypto.provider` via reflection.
+ */
+object MissingAlgoProvider {
+
+    private const val TAG = "MissingAlgoProvider"
+    private val registered = java.util.concurrent.atomic.AtomicBoolean(false)
+
+    private val patchProvider: Provider by lazy {
+        val bc = Security.getProvider("BC")
+        DelegatingBcProvider(bc)
+    }
+
+    fun register() {
+        if (!registered.compareAndSet(false, true)) return
+        try {
+            // 1. Replace cached provider in jcifs-ng classes
+            for (cn in listOf(
+                "jcifs.util.Crypto",
+                "jcifs.smb.NtlmUtil",
+                "jcifs.smb.NtlmPasswordAuthenticator",
+                "jcifs.ntlmssp.Type3Message",
+                "jcifs.smb.NtlmContext"
+            )) setProviderField(cn)
+
+            // 2. Verify
+            try {
+                val cl = Class.forName("jcifs.util.Crypto")
+                val getProv = cl.getDeclaredMethod("getProvider")
+                getProv.isAccessible = true
+                val actual = getProv.invoke(null) as Provider
+                Log.i(TAG, "Crypto.getProvider() => ${actual::class.java.simpleName} " +
+                    "(hasMD4=${actual.getService("MessageDigest", "MD4") != null}, " +
+                    "hasAESCMAC=${actual.getService("Mac", "AESCMAC") != null})")
+            } catch (ve: Exception) {
+                Log.w(TAG, "Verification failed after injection", ve)
+            }
+
+        } catch (e: Exception) {
+            Log.e(TAG, "Failed to inject algorithms", e)
+        }
+    }
+
+    private fun setProviderField(clsName: String) {
+        try {
+            val cls = Class.forName(clsName)
+            for (f in cls.declaredFields) {
+                if (java.lang.reflect.Modifier.isStatic(f.modifiers) &&
+                    Provider::class.java.isAssignableFrom(f.type)) {
+                    f.isAccessible = true
+                    f.set(null, patchProvider)
+                    Log.i(TAG, "Set $clsName.${f.name} = DelegatingBcProvider")
+                    return
+                }
+            }
+            Log.i(TAG, "No static Provider field in $clsName")
+        } catch (_: ClassNotFoundException) {
+            Log.i(TAG, "Class not found: $clsName")
+        }
+    }
+
+    // ── MD4 MessageDigestSpi ────────────────────────────────────
+
+    class Md4Spi : MessageDigestSpi() {
+        private val d = MD4Digest()
+        override fun engineGetDigestLength() = d.digestSize
+        override fun engineUpdate(b: Byte) { d.update(b) }
+        override fun engineUpdate(b: ByteArray, o: Int, l: Int) { d.update(b, o, l) }
+        override fun engineDigest(): ByteArray {
+            val r = ByteArray(d.digestSize); d.doFinal(r, 0); return r
+        }
+        override fun engineReset() { d.reset() }
+    }
+
+    // ── AESCMAC MacSpi ─────────────────────────────────────────
+    class AesCmacSpi : MacSpi() {
+        private val mac = CMac(AESEngine.newInstance())
+        override fun engineInit(key: java.security.Key, params: AlgorithmParameterSpec?) {
+            val raw = key.encoded ?: throw java.security.InvalidKeyException("AESCMAC key has no encoded form")
+            mac.init(KeyParameter(raw))
+        }
+        override fun engineUpdate(inp: Byte) { mac.update(inp) }
+        override fun engineUpdate(inp: ByteArray, o: Int, l: Int) { mac.update(inp, o, l) }
+        override fun engineDoFinal(): ByteArray {
+            val r = ByteArray(mac.macSize); mac.doFinal(r, 0); return r
+        }
+        override fun engineGetMacLength() = mac.macSize
+        override fun engineReset() { mac.reset() }
+    }
+
+    // ── Delegating provider ─────────────────────────────────────
+
+    /** A "BC"-named provider that delegates to [bc] except for patched algorithms. */
+    private class DelegatingBcProvider(
+        private val bc: Provider?
+    ) : Provider("BC", bc?.version ?: 1.0, "BC + patches") {
+
+        init {
+            putService(Service(this, "MessageDigest", "MD4",
+                Md4Spi::class.java.name, null, null))
+            putService(Service(this, "Mac", "AESCMAC",
+                AesCmacSpi::class.java.name, null, null))
+        }
+
+        override fun getService(type: String, algorithm: String): Service? {
+            if (type == "MessageDigest" && algorithm.equals("MD4", ignoreCase = true)) return super.getService(type, algorithm)
+            if (type == "Mac" && algorithm.equals("AESCMAC", ignoreCase = true)) return super.getService(type, algorithm)
+            return bc?.getService(type, algorithm)
+        }
+
+        override fun getServices(): MutableSet<Service> {
+            val s = (bc?.getServices() ?: emptySet<Service>()).toMutableSet()
+            s.addAll(super.getServices())
+            return s
+        }
+    }
+}

app/src/main/java/com/example/androidbackupgui/backup/RemoteTransport.kt

@@ -42,6 +42,8 @@ interface RemoteTransport {
 
     suspend fun delete(remotePath: String): AppResult<Unit>
     suspend fun exists(remotePath: String): AppResult<Boolean>
+    /** Get the size of a remote file in bytes. Returns [AppResult.Failure] if not found. */
+    suspend fun fileSize(remotePath: String): AppResult<Long>
 
     companion object {
 

app/src/main/java/com/example/androidbackupgui/backup/RestBridgeRunner.kt

@@ -19,6 +19,10 @@ class RestBridgeRunner {
 
     private val TAG = "RestBridgeRunner"
 
+    /** Cached transport to reuse SMB sessions across bridge instances. */
+    private var cachedTransport: RemoteTransport? = null
+    private var cachedTransportKey: String? = null
+
     /**
      * Start a REST bridge for the given [backend], execute [block] with the
      * bridge URL, then stop and clean up.
@@ -49,14 +53,22 @@ class RestBridgeRunner {
             return block(repoPath)
         }
 
-        val transport = transportFactory(backend, backendUrl, backendUser, backendPass, backendShare, backendDomain)
-            ?: return block(repoPath)
+        // Reuse cached transport (same SMB session) for consistent cross-bridge visibility
+        val key = "$backend|$backendUrl|$backendUser|$backendShare|$backendDomain"
+        if (cachedTransportKey != key) {
+            cachedTransport?.let { Log.d(TAG, "discarding stale cached transport") }
+            val t = transportFactory(backend, backendUrl, backendUser, backendPass, backendShare, backendDomain)
+                ?: return block(repoPath)
+            cachedTransport = t
+            cachedTransportKey = key
+        }
+        val transport = cachedTransport!!
 
         val remoteBase = buildRemoteBase(backend, backendUrl, backendShare, repoPath)
-        val bridge = ResticRestBridge(transport, remoteBase, cacheDir)
+        val bridge = ResticRestBridge(transport, remoteBase, repoPath, cacheDir)
 
         try {
-            bridge.start()
+            bridge.start(0)
             val port = bridge.listeningPort
             if (port < 0) {
                 throw IllegalStateException("REST bridge failed to bind a port")

app/src/main/java/com/example/androidbackupgui/backup/ResticRepoInit.kt

@@ -63,22 +63,72 @@ class ResticRepoInit(
         if (result.exitCode == 0) {
             return AppResult.Success(Unit)
         }
-        // exitCode 1 = config already exists; verify the repo is actually usable
+        // exitCode 1: check if it's "config already exists" or a real error
         if (result.exitCode == 1) {
-            val verify = runner.runRestic(env, "snapshots", "--json")
+            if (!isConfigExistsError(result.stderr)) {
+                // Exit code 1 from restic can also mean connection/backend errors (500, timeout, etc.)
+                return err(AppError.Restic("restic init 失败: ${result.stderr.take(300).trim()}", result.exitCode, result.stderr))
+            }
+            var verify = runner.runRestic(env, "snapshots", "--json")
             if (verify.exitCode == 0) {
                 // Repo is healthy — already initialized with matching password
                 Log.i(TAG, "init: repo already initialized and verified")
                 return AppResult.Success(Unit)
             }
-            // Config exists but repo is corrupted (wrong password, missing keys, etc.)
+            // Lock-related failure → try unlock then retry
+            if (isLockError(verify.stderr)) {
+                Log.w(TAG, "init: stale lock detected, running unlock")
+                runner.runRestic(env, "unlock")
+                verify = runner.runRestic(env, "snapshots", "--json")
+                if (verify.exitCode == 0) {
+                    Log.i(TAG, "init: repo verified after unlock")
+                    return AppResult.Success(Unit)
+                }
+            }
+            // Config exists but verification failed — diagnose the cause
+            val detail = diagnoseInitFailure(verify.stderr)
             return err(
-                AppError.Restic("仓库已存在但无法验证", verify.exitCode, verify.stderr)
+                AppError.Restic("仓库已存在但无法验证: $detail", verify.exitCode, verify.stderr)
             )
         }
         return err(AppError.Restic("restic init 失败", result.exitCode, result.stderr))
     }
 
+    /** Check if [restic init]'s stderr indicates config already exists (vs a real error). */
+    private fun isConfigExistsError(stderr: String): Boolean {
+        val lower = stderr.lowercase()
+        return lower.contains("already exists") ||
+               lower.contains("config file already exists")
+    }
+
+    /** Check if stderr indicates a stale repository lock. */
+    private fun isLockError(stderr: String): Boolean {
+        val lower = stderr.lowercase()
+        return lower.contains("lock") ||
+               lower.contains("unable to create") ||
+               lower.contains("already locked")
+    }
+
+    /** Parse restic stderr to produce a user-facing diagnosis string. */
+    private fun diagnoseInitFailure(stderr: String): String {
+        val lower = stderr.lowercase()
+        return when {
+            lower.contains("wrong password") ||
+            lower.contains("password is incorrect") ||
+            lower.contains("unable to decrypt") ||
+            lower.contains("wrong key") ||
+            lower.contains("invalid password") ||
+            lower.contains("decryption") -> "密码不正确，请确认仓库密码"
+            lower.contains("key") && (lower.contains("not found") || lower.contains("missing")) ->
+                "密钥文件缺失，仓库可能已损坏"
+            lower.contains("permission") || lower.contains("access denied") ->
+                "权限不足，请检查目录权限"
+            lower.contains("not a directory") || lower.contains("no such file") ->
+                "仓库路径无效或不可访问"
+            else -> "仓库可能已损坏或密码不正确（${stderr.take(200).trim()}）"
+        }
+    }
+
     // ── Public URL helper ──────────────────────────────
 
     /** Build a display-friendly repository URL for UI. */

app/src/main/java/com/example/androidbackupgui/backup/ResticRestBridge.kt

@@ -4,9 +4,9 @@ import android.util.Log
 import fi.iki.elonen.NanoHTTPD
 import fi.iki.elonen.NanoHTTPD.IHTTPSession
 import kotlinx.coroutines.runBlocking
+import java.io.ByteArrayInputStream
 import java.io.File
 import java.util.UUID
-
 /**
  * NanoHTTPD-based REST bridge implementing the restic REST backend API.
  *
@@ -14,10 +14,15 @@ import java.util.UUID
  * can read/write blobs directly to SMB/WebDAV without a local staging repo.
  *
  * Port is auto-assigned (0); use [listeningPort] after start().
+ *
+ * @param repoPath repository path from the bridge URL (e.g. "backup").
+ *                 Stripped from incoming URIs so that the remoteBase SMB path
+ *                 does not get double-nested with the repo prefix.
  */
 class ResticRestBridge(
     private val transport: RemoteTransport,
     private val remoteBase: String,
+    private val repoPath: String,
     private val cacheDir: File
 ) : NanoHTTPD(0) {
 
@@ -56,6 +61,14 @@ class ResticRestBridge(
         session: IHTTPSession
     ): Response {
         val path = uri.trimEnd('/')
+        // Strip the repoPath prefix (/backup/...) from the URI so that type/name
+        // parsing sees only the restic REST API segment.
+        val stripPrefix = if (repoPath.isNotEmpty()) "/${repoPath.trim('/')}" else ""
+        val strippedPath = if (stripPrefix.isNotEmpty() && path.startsWith(stripPrefix)) {
+            path.removePrefix(stripPrefix).ifEmpty { "/" }
+        } else {
+            path
+        }
 
         // POST {path}?create=true -> mkdirs
         if (method == NanoHTTPD.Method.POST && params["create"] == "true") {
@@ -71,7 +84,7 @@ class ResticRestBridge(
             }
         }
 
-        val segments = path.split("/").filter { it.isNotEmpty() }
+        val segments = strippedPath.split("/").filter { it.isNotEmpty() }
 
         if (segments.isEmpty()) {
             return newFixedLengthResponse(Response.Status.NOT_FOUND, "text/plain", "Invalid path")
@@ -109,13 +122,42 @@ class ResticRestBridge(
      * Stream body from session input to a temp file to avoid OOM on large blobs.
      * Returns the temp file (caller must delete).
      */
-    private fun streamBodyToFile(session: IHTTPSession, tmpDir: File): File? {
+    private fun streamBodyToFile(session: IHTTPSession, tmpDir: File): Result<File> {
+        val started = System.currentTimeMillis()
         return try {
             val tmpFile = File(tmpDir, "restic_blob_${UUID.randomUUID()}")
+            val contentLength = session.headers["content-length"]?.toLongOrNull() ?: -1L
             val input = (session as NanoHTTPD.HTTPSession).inputStream
-            tmpFile.outputStream().use { output -> input.copyTo(output) }
-            tmpFile
-        } catch (_: Exception) { null }
+            Log.d(TAG, "streamBodyToFile: reading body (content-length=$contentLength)...")
+            tmpFile.outputStream().use { output ->
+                if (contentLength > 0) {
+                    // Read exactly Content-Length bytes to avoid blocking on keep-alive
+                    val buf = ByteArray(8192)
+                    var remaining = contentLength
+                    while (remaining > 0) {
+                        val toRead = minOf(buf.size.toLong(), remaining).toInt()
+                        val n = input.read(buf, 0, toRead)
+                        if (n == -1) break
+                        output.write(buf, 0, n)
+                        remaining -= n
+                    }
+                    if (remaining > 0) {
+                        Log.w(TAG, "streamBodyToFile: body truncated, expected $contentLength bytes but got EOF after ${contentLength - remaining}")
+                    }
+                    Unit
+                } else {
+                    input.copyTo(output)
+                }
+            }
+            val elapsed = System.currentTimeMillis() - started
+            val bytes = tmpFile.length()
+            Log.i(TAG, "streamBodyToFile: read $bytes bytes in ${elapsed}ms")
+            Result.success(tmpFile)
+        } catch (e: Exception) {
+            val elapsed = System.currentTimeMillis() - started
+            Log.w(TAG, "streamBodyToFile failed after ${elapsed}ms", e)
+            Result.failure(e)
+        }
     }
 
     @Suppress("UNUSED_PARAMETER")
@@ -127,10 +169,15 @@ class ResticRestBridge(
         val remotePath = "$remoteBase/config"
         when (method) {
             NanoHTTPD.Method.HEAD -> {
-                when (val result = transport.exists(remotePath)) {
+                when (val exists = transport.exists(remotePath)) {
                     is AppResult.Success -> {
-                        if (result.data) {
-                            newFixedLengthResponse(Response.Status.OK, "application/octet-stream", "")
+                        if (exists.data) {
+                            val sizeResult = transport.fileSize(remotePath)
+                            val fileSize = if (sizeResult is AppResult.Success) sizeResult.data else 0L
+                            newFixedLengthResponse(
+                                Response.Status.OK, "application/octet-stream",
+                                ByteArrayInputStream(ByteArray(0)), fileSize
+                            )
                         } else {
                             newFixedLengthResponse(Response.Status.NOT_FOUND, "text/plain", "")
                         }
@@ -145,8 +192,8 @@ class ResticRestBridge(
                 try {
                     when (transport.download(remotePath, tempFile.absolutePath)) {
                         is AppResult.Success -> {
-                            val bytes = tempFile.readBytes()
-                            newChunkedResponse(Response.Status.OK, "application/octet-stream", bytes.inputStream())
+                            val data = tempFile.readBytes()
+                            newFixedLengthResponse(Response.Status.OK, "application/octet-stream", data.inputStream(), data.size.toLong())
                         }
                         is AppResult.Failure -> newFixedLengthResponse(
                             Response.Status.NOT_FOUND, "text/plain", ""
@@ -157,10 +204,12 @@ class ResticRestBridge(
                 }
             }
             NanoHTTPD.Method.POST -> {
-                val tmpFile = streamBodyToFile(session, cacheDir)
-                if (tmpFile == null) return@runBlocking newFixedLengthResponse(
-                    Response.Status.INTERNAL_ERROR, "text/plain", "body read failed"
+                val tmpResult = streamBodyToFile(session, cacheDir)
+                if (tmpResult.isFailure) return@runBlocking newFixedLengthResponse(
+                    Response.Status.INTERNAL_ERROR, "text/plain",
+                    "body read failed: ${tmpResult.exceptionOrNull()?.message ?: "unknown"}"
                 )
+                val tmpFile = tmpResult.getOrThrow()
                 try {
                     when (transport.upload(tmpFile.absolutePath, remotePath)) {
                         is AppResult.Success -> newFixedLengthResponse(
@@ -275,14 +324,14 @@ class ResticRestBridge(
                         response.addHeader("Content-Length", chunkSize.toString())
                         return@runBlocking response
                     }
-
-                    // Full file — stream directly without loading into memory
+                    // Full file — read into memory (blobs are typically small)
+                    val data = tempFile.readBytes()
                     val response = newChunkedResponse(
                         Response.Status.OK,
                         "application/octet-stream",
-                        tempFile.inputStream()
+                        data.inputStream()
                     )
-                    response.addHeader("Content-Length", tempFile.length().toString())
+                    response.addHeader("Content-Length", data.size.toString())
                     response
                 }
                 is AppResult.Failure -> newFixedLengthResponse(
@@ -302,10 +351,12 @@ class ResticRestBridge(
         session: IHTTPSession
     ): Response = runBlocking {
         val remotePath = "$remoteBase/$type/$name"
-        val tmpFile = streamBodyToFile(session, cacheDir)
-        if (tmpFile == null) return@runBlocking newFixedLengthResponse(
-            Response.Status.INTERNAL_ERROR, "text/plain", "body read failed"
+        val tmpResult = streamBodyToFile(session, cacheDir)
+        if (tmpResult.isFailure) return@runBlocking newFixedLengthResponse(
+            Response.Status.INTERNAL_ERROR, "text/plain",
+            "body read failed: ${tmpResult.exceptionOrNull()?.message ?: "unknown"}"
         )
+        val tmpFile = tmpResult.getOrThrow()
         try {
             when (transport.upload(tmpFile.absolutePath, remotePath)) {
                 is AppResult.Success -> newFixedLengthResponse(

app/src/main/java/com/example/androidbackupgui/backup/SmbTransport.kt

@@ -14,6 +14,7 @@ import kotlinx.coroutines.withContext
 import kotlinx.coroutines.CancellationException
 import java.io.File
 import java.util.Properties
+import java.util.concurrent.atomic.AtomicBoolean
 
 class SmbTransport(
     private val host: String,
@@ -22,10 +23,21 @@ class SmbTransport(
     private val password: String,
     private val domain: String = "",
     private val bufferSize: Int = 8192,
-    private val smbSigning: Boolean = true
+    private val smbSigning: Boolean = false
 ): RemoteTransport {
-    companion object { private const val TAG = "SmbTransport" }
+    companion object {
+        private const val TAG = "SmbTransport"
+
+        /** Register missing JCA algorithms for jcifs-ng (MD4, AESCMAC, etc.). */
+        private val patchesRegistered = AtomicBoolean(false)
+        fun registerMissingAlgorithms() {
+            if (patchesRegistered.compareAndSet(false, true)) {
+                MissingAlgoProvider.register()
+            }
+        }
+    }
     private val context: CIFSContext by lazy {
+        registerMissingAlgorithms()
         val props = Properties().apply {
             // Force SMB 2.0.2 minimum — SMB1 is disabled on modern Windows
             setProperty("jcifs.smb.client.minVersion", "SMB202")
@@ -33,7 +45,7 @@ class SmbTransport(
             // Shorter timeouts for Android
             setProperty("jcifs.smb.client.responseTimeout", "15000")
             setProperty("jcifs.smb.client.connTimeout", "10000")
-            // Enable SMB signing for security (prevents tampering) — disable for legacy servers
+            // SMB signing (disabled by default — most home servers don't support it)
             if (smbSigning) {
                 setProperty("jcifs.smb.client.signingEnabled", "true")
                 setProperty("jcifs.smb.client.encryptionEnabled", "true")
@@ -47,7 +59,9 @@ class SmbTransport(
         }
     }
 
+    /** Build a full SMB URL. If [path] is already a full URL, pass through. */
     private fun buildUrl(path: String): String {
+        if (path.startsWith("smb://")) return path
         val cleanPath = path.trimStart('/')
         val sharePath = if (share.isNotEmpty()) "$share/$cleanPath" else cleanPath
         return "smb://$host/$sharePath"
@@ -82,8 +96,18 @@ class SmbTransport(
                         }
                     }
                 }
+                // Re-read with a fresh SmbFile handle to verify (jcifs-ng may have stale handle)
+                val freshRemote = SmbFile(buildUrl(remotePath), context)
+                val actualSize = freshRemote.length()
+                Log.i(TAG, "upload done: $fileSize bytes local, $actualSize bytes on SMB")
+                if (actualSize != fileSize) {
+                    Log.w(TAG, "upload size mismatch: local=$fileSize smb=$actualSize")
+                    // Try re-opening the output stream to flush any pending writes
+                    SmbFileOutputStream(remote).use { it.write(ByteArray(0)) }
+                    val retrySize = freshRemote.length()
+                    Log.w(TAG, "upload retry: smb=$retrySize bytes")
+                }
                 onProgress(RemoteTransport.TransferProgress("completed", 1, 1, remotePath))
-                Log.i(TAG, "upload $localPath -> ${buildUrl(remotePath)} ($fileSize bytes)")
                 AppResult.Success(Unit)
             } catch (e: CancellationException) {
                 throw e
@@ -184,15 +208,15 @@ class SmbTransport(
             } catch (e: SmbException) {
                 // STATUS_OBJECT_NAME_COLLISION (0xC0000035): directory already exists — not an error
                 if (e.ntStatus == 0xC0000035.toInt()) {
-                AppResult.Success(Unit)
+                    AppResult.Success(Unit)
                 } else {
-                    Log.e(TAG, "mkdirs failed: $remotePath — ${e.message}")
+                    Log.e(TAG, "mkdirs failed: $remotePath — ntStatus=0x${e.ntStatus.toString(16)} msg=${e.message} cause=${e.cause}")
                     err(AppError.Remote("SMB 创建目录失败", "mkdirs", cause = e))
                 }
             } catch (e: CancellationException) {
                 throw e
             } catch (e: Exception) {
-                Log.e(TAG, "mkdirs failed: $remotePath — ${e.message}")
+                Log.e(TAG, "mkdirs failed: $remotePath — ${e::class.java.name}: ${e.message} cause=${e.cause?.message}")
                 err(AppError.Remote("SMB 创建目录失败", "mkdirs", cause = e))
             }
         }
@@ -229,4 +253,17 @@ class SmbTransport(
                 err(AppError.Remote("SMB 检查失败", "exists", cause = e))
             }
         }
+
+    override suspend fun fileSize(remotePath: String): AppResult<Long> =
+        withContext(Dispatchers.IO) {
+            try {
+                val file = smbFile(remotePath)
+                if (!file.exists()) return@withContext err(AppError.Remote("文件不存在", "fileSize"))
+                AppResult.Success(file.length())
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: Exception) {
+                err(AppError.Remote("SMB 获取文件大小失败", "fileSize", cause = e))
+            }
+        }
 }

app/src/main/java/com/example/androidbackupgui/backup/WebdavTransport.kt

@@ -180,4 +180,19 @@ class WebdavTransport(
                 err(AppError.Remote("WebDAV 检查失败", "exists", cause = e))
             }
         }
+
+    override suspend fun fileSize(remotePath: String): AppResult<Long> =
+        withContext(Dispatchers.IO) {
+            try {
+                val url = buildUrl(remotePath)
+                if (!sardine.exists(url)) return@withContext err(AppError.Remote("文件不存在", "fileSize"))
+                val resources = sardine.list(url)
+                val size = resources.firstOrNull()?.contentLength ?: 0L
+                AppResult.Success(size)
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: Exception) {
+                err(AppError.Remote("WebDAV 获取文件大小失败", "fileSize", cause = e))
+            }
+        }
 }

app/src/main/java/com/example/androidbackupgui/ui/ConfigViewModel.kt

@@ -19,6 +19,7 @@ import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.io.File
+import java.util.concurrent.atomic.AtomicBoolean
 
 /** UI-visible state driven by [ConfigViewModel]. */
 data class ConfigUiState(
@@ -105,6 +106,8 @@ class ConfigViewModel(application: Application) : AndroidViewModel(application)
     private val _uiState = MutableStateFlow(ConfigUiState())
     val uiState: StateFlow<ConfigUiState> = _uiState.asStateFlow()
 
+    /** Guards against concurrent [initResticRepo] calls. */
+    private val initGuard = AtomicBoolean(false)
     /** Read config from file and refresh restic status. */
     fun load() {
         val config = BackupConfig.fromFile(configFile)
@@ -159,6 +162,10 @@ class ConfigViewModel(application: Application) : AndroidViewModel(application)
     // ── Async restic operations ──────────────────────────────────────
 
     fun initResticRepo(form: ResticForm) {
+        if (!initGuard.compareAndSet(false, true)) {
+            Log.w(TAG, "initResticRepo: already in progress, ignoring")
+            return
+        }
         Log.i(TAG, "initResticRepo called: repo=${form.repo} backend=${form.backend}")
 
         if (!prepareRestic()) {
@@ -190,18 +197,19 @@ class ConfigViewModel(application: Application) : AndroidViewModel(application)
                 if (result.isSuccess) {
                     _operationEvents.emit(OperationEvent.InitCompleted)
                     _uiState.update { it.copy(resticStatus = it.resticStatus.copy(
-                        message = "仓库初始化成功: ${form.repo}", initButtonEnabled = true
+                        message = "仓库初始化成功: ${form.repo}"
                     ))}
                     refreshResticStatus(form)
                 } else {
                     _operationEvents.emit(OperationEvent.InitFailed)
                     Log.e(TAG, "initResticRepo failed: ${result.exceptionOrNull()?.message}")
                     _uiState.update { it.copy(resticStatus = it.resticStatus.copy(
-                        message = "初始化失败: ${result.exceptionOrNull()?.message}", initButtonEnabled = true
+                        message = "初始化失败: ${result.exceptionOrNull()?.message}"
                     ))}
+                    refreshResticStatus(form)
                 }
             } finally {
-                _uiState.update { it.copy(resticStatus = it.resticStatus.copy(initButtonEnabled = true)) }
+                initGuard.set(false)
             }
         }
     }