Add envelope key initialization

powerauth-java-crypto/src/main/java/io/getlime/security/powerauth/crypto/lib/encryptor/ecies/EciesEncryptor.java

@@ -95,6 +95,20 @@ public EciesEncryptor(final EciesEnvelopeKey envelopeKey, final byte[] sharedInf
         this.canEncryptData = true;
     }
 
+    /**
+     * Initialize envelope key for encryptor using provided ephemeral public key. This method is used when the encryptor
+     * parameters are transported over network and the encryptor is reconstructed on another server using envelope key
+     * and sharedInfo2 parameter.
+     *
+     * @param ephemeralPublicKeyBytes Ephemeral public key for ECIES.
+     * @throws EciesException In case envelope key initialization fails.
+     */
+    public void initEnvelopeKey(byte[] ephemeralPublicKeyBytes) throws EciesException {
+        envelopeKey = EciesEnvelopeKey.fromPublicKey(publicKey, sharedInfo1);
+        // Invalidate this encryptor for encryption
+        canEncryptData = false;
+    }
+
     /**
      * Encrypt data.
      *