org.bitcoinj.crypto

Interface KeyCrypter

All Superinterfaces:

Serializable

All Known Implementing Classes:

KeyCrypterScrypt

public interface KeyCrypter
extends Serializable

A KeyCrypter can be used to encrypt and decrypt a message. The sequence of events to encrypt and then decrypt a message are as follows:

(1) Ask the user for a password. deriveKey() is then called to create an KeyParameter. This contains the AES key that will be used for encryption.

(2) Encrypt the message using encrypt(), providing the message bytes and the KeyParameter from (1). This returns an EncryptedData which contains the encryptedPrivateKey bytes and an initialisation vector.

(3) To decrypt an EncryptedData, repeat step (1) to get a KeyParameter, then call decrypt().

There can be different algorithms used for encryption/ decryption so the getUnderstoodEncryptionType is used to determine whether any given KeyCrypter can understand the type of encrypted data you have.

Method Summary

Modifier and Type	Method and Description
byte[]	decrypt(EncryptedData encryptedBytesToDecode, org.spongycastle.crypto.params.KeyParameter aesKey) Decrypt the provided encrypted bytes, converting them into unencrypted bytes.
org.spongycastle.crypto.params.KeyParameter	deriveKey(CharSequence password) Create a KeyParameter (which typically contains an AES key)
EncryptedData	encrypt(byte[] plainBytes, org.spongycastle.crypto.params.KeyParameter aesKey) Encrypt the supplied bytes, converting them into ciphertext.
Protos.Wallet.EncryptionType	getUnderstoodEncryptionType() Return the EncryptionType enum value which denotes the type of encryption/ decryption that this KeyCrypter can understand.

Method Detail

getUnderstoodEncryptionType

Protos.Wallet.EncryptionType getUnderstoodEncryptionType()

Return the EncryptionType enum value which denotes the type of encryption/ decryption that this KeyCrypter can understand.

deriveKey

org.spongycastle.crypto.params.KeyParameter deriveKey(CharSequence password)
                                               throws KeyCrypterException

Create a KeyParameter (which typically contains an AES key)

Parameters:

password -

Returns:

KeyParameter The KeyParameter which typically contains the AES key to use for encrypting and decrypting

Throws:

KeyCrypterException

decrypt

byte[] decrypt(EncryptedData encryptedBytesToDecode,
               org.spongycastle.crypto.params.KeyParameter aesKey)
        throws KeyCrypterException

Decrypt the provided encrypted bytes, converting them into unencrypted bytes.

Throws:

KeyCrypterException - if decryption was unsuccessful.

encrypt

EncryptedData encrypt(byte[] plainBytes,
                      org.spongycastle.crypto.params.KeyParameter aesKey)
               throws KeyCrypterException

Encrypt the supplied bytes, converting them into ciphertext.

Returns:

encryptedPrivateKey An encryptedPrivateKey containing the encrypted bytes and an initialisation vector.

Throws:

KeyCrypterException - if encryption was unsuccessful