diff --git a/tests/pico-hsm/test_052_aes_ext.py b/tests/pico-hsm/test_052_aes_ext.py
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+++ b/tests/pico-hsm/test_052_aes_ext.py
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+"""
+/*
+ * This file is part of the Pico HSM distribution (https://github.com/polhenarejos/pico-hsm).
+ * Copyright (c) 2022 Pol Henarejos.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+"""
+
+import pytest
+import os
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+import cryptography.exceptions
+from picohsm import APDUResponse, DOPrefixes, EncryptionMode, SWCodes, AES
+from picohsm.const import DEFAULT_DKEK_SHARES
+from const import DEFAULT_DKEK
+from binascii import hexlify
+
+MESSAGE = b'a secret message'
+AAD = b'this is a tag for AAD'
+
+def test_prepare_aes(device):
+    device.initialize(dkek_shares=DEFAULT_DKEK_SHARES)
+    resp = device.import_dkek(DEFAULT_DKEK)
+    resp = device.import_dkek(DEFAULT_DKEK)
+
+def generate_key(device, size):
+    pkey = os.urandom(size // 8)
+    keyid = device.import_key(pkey)
+    return pkey, keyid
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_ecb(device, size):
+    pkey, keyid = generate_key(device, size)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.ECB, MESSAGE)
+
+    cipher = Cipher(algorithms.AES(pkey), modes.ECB())
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.ECB, ctA)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_cbc_no_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.CBC, MESSAGE)
+
+    iv = b'\x00' * 16
+    cipher = Cipher(algorithms.AES(pkey), modes.CBC(iv))
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.CBC, ctA)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_cbc_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    iv = os.urandom(16)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.CBC, MESSAGE, iv=iv)
+
+    cipher = Cipher(algorithms.AES(pkey), modes.CBC(iv))
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.CBC, ctA, iv=iv)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_ofb_no_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.OFB, MESSAGE)
+
+    iv = b'\x00' * 16
+    cipher = Cipher(algorithms.AES(pkey), modes.OFB(iv))
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.OFB, ctA)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_ofb_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    iv = os.urandom(16)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.OFB, MESSAGE, iv=iv)
+
+    cipher = Cipher(algorithms.AES(pkey), modes.OFB(iv))
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.OFB, ctA, iv=iv)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_cfb_no_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.CFB, MESSAGE)
+
+    iv = b'\x00' * 16
+    cipher = Cipher(algorithms.AES(pkey), modes.CFB(iv))
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.CFB, ctA)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_cfb_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    iv = os.urandom(16)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.CFB, MESSAGE, iv=iv)
+
+    cipher = Cipher(algorithms.AES(pkey), modes.CFB(iv))
+    encryptor = cipher.encryptor()
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.CFB, ctA, iv=iv)
+    decryptor = cipher.decryptor()
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_gcm_no_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.GCM, MESSAGE, aad=AAD)
+
+    iv = b'\x00' * 16
+    encryptor = Cipher(algorithms.AES(pkey), modes.GCM(iv)).encryptor()
+    encryptor.authenticate_additional_data(AAD)
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB + encryptor.tag)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.GCM, ctA, aad=AAD)
+    decryptor = Cipher(algorithms.AES(pkey), modes.GCM(iv, encryptor.tag)).decryptor()
+    decryptor.authenticate_additional_data(AAD)
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)
+
+@pytest.mark.parametrize(
+    "size", [128, 192, 256]
+)
+def test_aes_gcm_iv(device, size):
+    pkey, keyid = generate_key(device, size)
+    iv = os.urandom(16)
+    ctA = device.aes(keyid, EncryptionMode.ENCRYPT, AES.GCM, MESSAGE, iv=iv, aad=AAD)
+
+    encryptor = Cipher(algorithms.AES(pkey), modes.GCM(iv)).encryptor()
+    encryptor.authenticate_additional_data(AAD)
+    ctB = encryptor.update(MESSAGE) + encryptor.finalize()
+    assert(ctA == ctB + encryptor.tag)
+
+    dtA = device.aes(keyid, EncryptionMode.DECRYPT, AES.GCM, ctA, iv=iv, aad=AAD)
+    decryptor = Cipher(algorithms.AES(pkey), modes.GCM(iv, encryptor.tag)).decryptor()
+    decryptor.authenticate_additional_data(AAD)
+    dtB = decryptor.update(ctB) + decryptor.finalize()
+    assert(dtA == dtB)
+    assert(dtA == MESSAGE)
+    device.delete_key(keyid)