App signature modifications

WebileApps · Dec 17, 2024 · 0ee281b · 0ee281b
1 parent ebc870d
commit 0ee281b
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Showing 2 changed files with 54 additions and 24 deletions.
diff --git a/protect/src/main/java/com/webileapps/safeguard/SecurityChecker.kt b/protect/src/main/java/com/webileapps/safeguard/SecurityChecker.kt
@@ -24,6 +24,10 @@ import androidx.core.content.ContextCompat
 import com.webileapps.safeguard.NetworkUtils.isProxySet
 import com.webileapps.safeguard.NetworkUtils.isVPNActive
 import com.webileapps.safeguard.NetworkUtils.isWifiSecure
+import java.io.File
+import java.io.FileInputStream
+import java.io.InputStream
+import java.security.MessageDigest
 import java.util.function.Consumer
 import kotlin.system.exitProcess
 
@@ -641,4 +645,47 @@ class SecurityChecker(private val context: Context, private val config: Security
         networkCallback = null
         connectivityManager = null
     }
+
+    fun generateFileChecksum(file: File, algorithm: String = "SHA-256"): String? {
+        try {
+            // Create a MessageDigest instance
+            val messageDigest = MessageDigest.getInstance(algorithm)
+
+            // Read file and update the digest
+            val inputStream: InputStream = FileInputStream(file)
+            val buffer = ByteArray(1024)
+            var bytesRead: Int
+            while (inputStream.read(buffer).also { bytesRead = it } != -1) {
+                messageDigest.update(buffer, 0, bytesRead)
+            }
+            inputStream.close()
+
+            // Convert the digest to a hexadecimal string
+            val hashBytes = messageDigest.digest()
+            return hashBytes.joinToString("") { "%02x".format(it) }
+        } catch (e: Exception) {
+            e.printStackTrace()
+            return null
+        }
+    }
+
+    fun validateFileChecksum(file: File, expectedChecksum: String, algorithm: String = "SHA-256"): Boolean {
+        val generatedChecksum = generateFileChecksum(file, algorithm)
+        return generatedChecksum != null && generatedChecksum.equals(expectedChecksum, ignoreCase = true)
+    }
+
+    fun checkFileIntegrity(filePath: String, expectedChecksum: String) {
+        val file = File(filePath)
+
+        if (file.exists()) {
+            val isValid = validateFileChecksum(file, expectedChecksum, "SHA-256")
+            if (isValid) {
+                Log.d("ChecksumValidation", "File is valid! Checksum matches.")
+            } else {
+                Log.e("ChecksumValidation", "File checksum mismatch! Possible tampering detected.")
+            }
+        } else {
+            Log.e("ChecksumValidation", "File does not exist: $filePath")
+        }
+    }
 }
diff --git a/protect/src/main/java/com/webileapps/safeguard/SignatureComparison.kt b/protect/src/main/java/com/webileapps/safeguard/SignatureComparison.kt
@@ -34,15 +34,15 @@ class SignatureComparison {
                 return false
             }
 
-            // Compute SHA-1 hash of the first signature
-            val appSignatureHash = getSHA1Hash(signatures[0].toByteArray())
-            if (appSignatureHash.isNullOrEmpty()) {
-                Log.e(TAG, "Error generating hash for the app's signature.")
-                return false
-            }
+
+            val md = MessageDigest.getInstance("SHA-1");
+            val originalDigest = md.digest(expectedSignatureHash.toByteArray())
+
+            val currentDigest = md.digest(signatures[0].toByteArray())
+
 
             // Compare with the expected signature hash
-            val isValid = expectedSignatureHash.equals(appSignatureHash, ignoreCase = true)
+            val isValid = MessageDigest.isEqual(originalDigest, currentDigest)
             if (isValid) {
                 Log.d(TAG, "App signature is valid.")
             } else {
@@ -56,21 +56,4 @@ class SignatureComparison {
         }
     }
 
-
-    private fun getSHA1Hash(signatureBytes: ByteArray): String? {
-        try {
-            val digest = MessageDigest.getInstance("SHA-1")
-            val hash = digest.digest(signatureBytes)
-
-            // Convert hash to a hexadecimal string
-            val hexString = StringBuilder()
-            for (b in hash) {
-                hexString.append(String.format("%02x", b))
-            }
-            return hexString.toString()
-        } catch (e: Exception) {
-            Log.e(TAG, "Error generating SHA-1 hash", e)
-            return null
-        }
-    }
     }