Package com.google.crypto.tink.integration.android

Class SharedPrefKeysetWriter

  • All Implemented Interfaces:
    KeysetWriter
    public final class SharedPrefKeysetWriter
extends java.lang.Object
implements KeysetWriter
    A KeysetWriter that can write keysets to private shared preferences on Android.

    We do not recommend new uses of this class. Instead, if you want to store a Tink keyset in shared preferences, serialize the keyset using TinkProtoKeysetFormat, and write it hex-encoded into your SharedPreferences manually.

    For example, to write an encrypted keyset to the shared preferences, you can replace this: 

    
 keysetHandle.write(
     new SharedPrefKeysetWriter(
         ApplicationProvider.getApplicationContext(), keysetName, null),
     keysetEncryptionAead);

    with this: 

    
 byte[] encryptedKeyset =
     TinkProtoKeysetFormat.serializeEncryptedKeyset(
         handle, keysetEncryptionAead, new byte[0]);
 SharedPreferences.Editor editor =
     PreferenceManager.getDefaultSharedPreferences(
             ApplicationProvider.getApplicationContext().getApplicationContext())
         .edit();
 boolean success = editor.putString(keysetName, Hex.encode(encryptedKeyset)).commit();

    and to write an unencrypted keyset to the shared preferences, you can replace this: 

    
 CleartextKeysetHandle.write(
     handle,
     new SharedPrefKeysetWriter(
         ApplicationProvider.getApplicationContext(), keysetName, null));

    with this: 

    
 byte[] serializedKeyset =
     TinkProtoKeysetFormat.serializeKeyset(handle, InsecureSecretKeyAccess.get());
 SharedPreferences.Editor editor =
     PreferenceManager.getDefaultSharedPreferences(
         ApplicationProvider.getApplicationContext().getApplicationContext())
     .edit();
 boolean success = editor.putString(keysetName, Hex.encode(serializedKeyset)).commit();

    • Constructor Summary

      Constructors 
      Constructor Description
      SharedPrefKeysetWriter​(android.content.Context context, java.lang.String keysetName, java.lang.String prefFileName)
      Creates a KeysetReader that hex-encodes and writes keysets to the preference name keysetName in the private shared preferences file prefFileName.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void write​(com.google.crypto.tink.proto.EncryptedKeyset keyset)
      Tries to write an EncryptedKeyset to some storage system.
      void write​(com.google.crypto.tink.proto.Keyset keyset)
      Tries to write a Keyset to some storage system.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • SharedPrefKeysetWriter

        public SharedPrefKeysetWriter​(android.content.Context context,
                              java.lang.String keysetName,
                              java.lang.String prefFileName)
        Creates a KeysetReader that hex-encodes and writes keysets to the preference name keysetName in the private shared preferences file prefFileName.

        If prefFileName is null, uses the default shared preferences file.

        Throws:
        java.io.IOException - if cannot write the keyset
        java.lang.IllegalArgumentException - if keysetName is null

    • Method Detail

      • write

        public void write​(com.google.crypto.tink.proto.Keyset keyset)
           throws java.io.IOException
        Description copied from interface: KeysetWriter
        Tries to write a Keyset to some storage system.
        Specified by:
        write in interface KeysetWriter
        Throws:
        java.io.IOException

      • write

        public void write​(com.google.crypto.tink.proto.EncryptedKeyset keyset)
           throws java.io.IOException
        Description copied from interface: KeysetWriter
        Tries to write an EncryptedKeyset to some storage system.
        Specified by:
        write in interface KeysetWriter
        Throws:
        java.io.IOException