Because you don't usually work directly with byte arrays, but rather with a base64 encoded version of such data, there also is a base64 version of the cipherer.

<crypt:b64AsymmetricCipherer id="encrypter" key-ref="privateKey" algorithm="RSA"
    provider="BC" mode="ENCRYPT" />

<crypt:b64AsymmetricCipherer id="decrypter" key-ref="publicKey" algorithm="RSA"
    provider="BC" mode="DECRYPT"/>

<crypt:publicKey id="publicKey" keystore-ref="keystore" alias="test"/>
<crypt:privateKey id="privateKey" keystore-ref="keystore" alias="test" password="password"/>
<crypt:keystore id="keystore" location="classpath:keystore.jks" password="password"/>

Decrypting a message is done using the same interface as for encrypting. The only difference is that the underlying mode of operation is set in configuration to DECRYPT.

Here's an example implementation:

import com.springcryptoutils.core.cipher.asymmetric.Base64EncodedCipherer;

public class MyBase64Encrypter {

    @Autowired
    @Qualifier("encrypter")
    private Base64EncodedCipherer encrypter;

    @Autowired
    @Qualifier("decrypter")
    private Base64EncodedCipherer decrypter;

    public void encryptAndDecrypt() {
        String b64encryptedMessage = encrypter.encrypt("a secret message");
        String decryptedMessage = decrypter.encrypt(b64encryptedMessage);
    }
}

If your encryption key is not static, you can configure a mapping by logical name in the xml configuration.

<crypt:asymmetricCiphererWithChooserByKeyId id="encrypter" keyMap-ref="keyMap"
    algorithm="RSA" provider="BC" mode="ENCRYPT"/>

<crypt:asymmetricCiphererWithChooserByKeyId id="decrypter" keyMap-ref="keyMap"
    algorithm="RSA" provider="BC" mode="DECRYPT"/>

<util:map id="keyMap">
    <entry key="publicKeyId">
        <crypt:publicKey keystore-ref="keystore" alias="test"/>
    </entry>
    <entry key="privateKeyId">
        <crypt:privateKey keystore-ref="keystore" alias="test" password="password"/>
    </entry>
</util:map>

<crypt:keystore id="keystore" location="classpath:keystore.jks" password="password"/>

Decrypting a message is done using the same interface as for encrypting. The only difference is that the underlying mode of operation is set in configuration to DECRYPT.

Here's an example implementation:

import com.springcryptoutils.core.cipher.asymmetric.CiphererWithChooserByKeyId;

public class MyCiphererWithChooserByKeyId {

    @Autowired
    @Qualifier("encrypter")
    private CiphererWithChooserByKeyId encrypter;

    @Autowired
    @Qualifier("decrypter")
    private CiphererWithChooserByKeyId decrypter;

    public void encryptAndDecrypt() {
        final byte[] message = new byte[] {4, 8, 15, 16, 23, 42};
        byte[] encryptedMessage = encrypter.encrypt("publicKeyId", message);
        byte[] decryptedMessage = decrypter.encrypt("privateKeyId", encryptedMessage);
    }
}

If your encryption key is not static and you need to work with base64 encoded data, you can configure a mapping by logical name in the xml configuration.

<crypt:b64AsymmetricCiphererWithChooserByKeyId id="encrypter" keyMap-ref="keyMap"
    algorithm="RSA" provider="BC" mode="ENCRYPT"/>

<crypt:b64AsymmetricCiphererWithChooserByKeyId id="decrypter" keyMap-ref="keyMap"
    algorithm="RSA" provider="BC" mode="DECRYPT"/>

<util:map id="keyMap">
    <entry key="publicKeyId">
        <crypt:publicKey keystore-ref="keystore" alias="test"/>
    </entry>
    <entry key="privateKeyId">
        <crypt:privateKey keystore-ref="keystore" alias="test" password="password"/>
    </entry>
</util:map>

<crypt:keystore id="keystore" location="classpath:keystore.jks" password="password"/>

Decrypting a message is done using the same interface as for encrypting. The only difference is that the underlying mode of operation is set in configuration to DECRYPT.

Here's an example implementation:

import com.springcryptoutils.core.cipher.asymmetric.Base64EncodedCiphererWithChooserByKeyId;

public class MyBase64EncodedCiphererWithChooserByKeyId {

    @Autowired
    @Qualifier("encrypter")
    private Base64EncodedCiphererWithChooserByKeyId encrypter;

    @Autowired
    @Qualifier("decrypter")
    private Base64EncodedCiphererWithChooserByKeyId decrypter;

    public void encryptAndDecrypt() {
        final String message = "this is a top-secret message";
        String b64encryptedMessage = encrypter.encrypt("publicKeyId", message);
        String decryptedMessage = decrypter.encrypt("privateKeyId", b64encryptedMessage);
    }
}