EncryptedFile

Artifact: androidx.security:security-crypto

Added in 1.0.0

Kotlin |Java

class EncryptedFile

Class used to create and read encrypted files. WARNING: The encrypted file should not be backed up with Auto Backup. When restoring the file it is likely the key used to encrypt it will no longer be present. You should exclude all EncryptedFiles from backup using backup rules. Be aware that if you are not explicitly calling setKeysetPrefName() there is also a silently-created default preferences file created at

    ApplicationProvider
         .getApplicationContext()
         .getFilesDir()
         .getParent() + "/shared_prefs/__androidx_security_crypto_encrypted_file_pref__"

This preferences file (or any others created with a custom specified location) also should be excluded from backups. Basic use of the class:

 MasterKey masterKey = new MasterKey.Builder(context)
     .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
     .build();

 File file = new File(context.getFilesDir(), "secret_data");
 EncryptedFile encryptedFile = EncryptedFile.Builder(
     context,
     file,
     masterKey,
     EncryptedFile.FileEncryptionScheme.AES256_GCM_HKDF_4KB
 ).build();

 // write to the encrypted file
 FileOutputStream encryptedOutputStream = encryptedFile.openFileOutput();

 // read the encrypted file
 FileInputStream encryptedInputStream = encryptedFile.openFileInput();

Summary

Nested types
`class EncryptedFile.Builder` This class is deprecated. Use `java.io.File` instead.
`enum EncryptedFile.FileEncryptionScheme` This enum is deprecated. Use `java.io.File` instead.

Nested types

class EncryptedFile.Builder

This class is deprecated.

Use java.io.File instead.

enum EncryptedFile.FileEncryptionScheme

This enum is deprecated.

Use java.io.File instead.

Public functions
`FileInputStream`	`openFileInput()` Opens a FileInputStream that reads encrypted files based on the previous settings.
`FileOutputStream`	`openFileOutput()` Opens a FileOutputStream for writing that automatically encrypts the data based on the provided settings.

Public functions

openFileInput

Added in 1.0.0

Deprecated in 1.1.0-beta01

fun openFileInput(): FileInputStream

Opens a FileInputStream that reads encrypted files based on the previous settings.

Please ensure that the same master key and keyset are used to decrypt or it will cause failures.

Returns
`FileInputStream`	The input stream to read previously encrypted data.

Throws
`java.security.GeneralSecurityException`	when a bad master key or keyset has been used
`java.io.FileNotFoundException`	when the file was not found
`java.io.IOException`	when other I/O errors occur

openFileOutput

Added in 1.0.0

Deprecated in 1.1.0-beta01

fun openFileOutput(): FileOutputStream

Opens a FileOutputStream for writing that automatically encrypts the data based on the provided settings.

Please ensure that the same master key and keyset are used to decrypt or it will cause failures.

Returns
`FileOutputStream`	The FileOutputStream that encrypts all data.

Throws
`java.security.GeneralSecurityException`	when a bad master key or keyset has been used
`java.io.IOException`	when the file already exists or is not available for writing