[FEAT/#5] EncryptedSharedPreferences로 데이터 암호화 하기

GO-SOPT-ANDROID · May 5, 2023 · 6bd9db2 · 6bd9db2
1 parent eaa8b9b
commit 6bd9db2
Show file tree

Hide file tree

Showing 4 changed files with 38 additions and 21 deletions.
diff --git a/app/build.gradle b/app/build.gradle
@@ -42,12 +42,14 @@ android {
 
 dependencies {
 
-    implementation 'androidx.core:core-ktx:1.9.0'
-    implementation 'androidx.fragment:fragment-ktx:1.5.7'
+    implementation 'androidx.core:core-ktx:1.10.0'
     implementation 'androidx.appcompat:appcompat:1.6.1'
     implementation 'com.google.android.material:material:1.8.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+
+    implementation 'androidx.fragment:fragment-ktx:1.5.7'
+    implementation "androidx.security:security-crypto-ktx:1.1.0-alpha06"
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
@@ -3,7 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <application
-        android:name=".Week2Application"
+        android:name=".GoSoptApplication"
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
@@ -15,22 +15,21 @@
 
         <activity
             android:name=".ui.login.LoginActivity"
-            android:exported="false"
-            android:windowSoftInputMode="adjustResize" />
-        <activity
-            android:name=".ui.signup.SignUpActivity"
-            android:exported="false"
-            android:windowSoftInputMode="adjustResize" />
-
-        <activity
-            android:name=".ui.main.MainActivity"
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <activity
+            android:name=".ui.signup.SignUpActivity"
+            android:exported="false" />
+
+        <activity
+            android:name=".ui.main.MainActivity"
+            android:exported="false" />
     </application>
 
 </manifest>
diff --git a/...a/org/android/go/sopt/Week2Application.kt → .../org/android/go/sopt/GoSoptApplication.kt b/...a/org/android/go/sopt/Week2Application.kt → .../org/android/go/sopt/GoSoptApplication.kt
@@ -3,10 +3,10 @@ package org.android.go.sopt
 import android.app.Application
 import org.android.go.sopt.util.PreferenceUtil
 
-class Week2Application: Application() {
+class GoSoptApplication: Application() {
     override fun onCreate() {
-        prefs = PreferenceUtil(applicationContext)
         super.onCreate()
+        prefs = PreferenceUtil(applicationContext)
     }
 
     companion object {

diff --git a/app/src/main/java/org/android/go/sopt/util/PreferenceUtil.kt b/app/src/main/java/org/android/go/sopt/util/PreferenceUtil.kt
@@ -2,20 +2,36 @@ package org.android.go.sopt.util
 
 import android.content.Context
 import android.content.SharedPreferences
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKey
 
 class PreferenceUtil(context: Context) {
-    private val prefs: SharedPreferences =
-        context.getSharedPreferences(SHARED_PREFS_NAME, Context.MODE_PRIVATE)
+    private val sharedPreferences: SharedPreferences by lazy {
+        // 암호화 할 마스터 키 생성
+        val masterKeyAlias = MasterKey
+            .Builder(context, MasterKey.DEFAULT_MASTER_KEY_ALIAS)
+            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+            .build()
 
-    fun getString(key: String, defValue: String?): String? {
-        return prefs.getString(key, defValue)
+        // key, value를 암호화 한 sharedPreferences 객체 생성
+        EncryptedSharedPreferences.create(
+            context,
+            FILE_NAME,
+            masterKeyAlias,
+            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+        )
     }
 
-    fun setString(key: String, str: String) {
-        prefs.edit().putString(key, str).apply()
+    fun getString(key: String, defaultValue: String?): String? {
+        return sharedPreferences.getString(key, defaultValue)
+    }
+
+    fun setString(key: String, newValue: String) {
+        sharedPreferences.edit().putString(key, newValue).apply()
     }
 
     companion object {
-        private const val SHARED_PREFS_NAME = "my_prefs"
+        private const val FILE_NAME = "encrypted_user_info"
     }
 }