Add files via upload

11 months ago · 7ba9525b5c
parent 90ce635987
commit 7ba9525b5c
62 changed files with 14974 additions and 0 deletions
--- a/pywidevine/L1/init.py
+++ b/pywidevine/L1/init.py
--- a/pywidevine/L1/pycache/init.cpython-37.pyc
+++ b/pywidevine/L1/pycache/init.cpython-37.pyc
--- a/pywidevine/L1/pycache/getPSSH.cpython-37.pyc
+++ b/pywidevine/L1/pycache/getPSSH.cpython-37.pyc
--- a/pywidevine/L1/cdm/init.py
+++ b/pywidevine/L1/cdm/init.py
--- a/pywidevine/L1/cdm/pycache/init.cpython-37.pyc
+++ b/pywidevine/L1/cdm/pycache/init.cpython-37.pyc
--- a/pywidevine/L1/cdm/pycache/cdm.cpython-37.pyc
+++ b/pywidevine/L1/cdm/pycache/cdm.cpython-37.pyc
--- a/pywidevine/L1/cdm/pycache/deviceconfig.cpython-37.pyc
+++ b/pywidevine/L1/cdm/pycache/deviceconfig.cpython-37.pyc
--- a/pywidevine/L1/cdm/pycache/key.cpython-37.pyc
+++ b/pywidevine/L1/cdm/pycache/key.cpython-37.pyc
--- a/pywidevine/L1/cdm/pycache/session.cpython-37.pyc
+++ b/pywidevine/L1/cdm/pycache/session.cpython-37.pyc
--- a/pywidevine/L1/cdm/cdm.py
+++ b/pywidevine/L1/cdm/cdm.py
@ -0,0 +1,362 @@
+import base64
+
+import os
+import time
+import binascii
+
+from google.protobuf.message import DecodeError
+from google.protobuf import text_format
+
+from pywidevine.L1.cdm.formats import wv_proto2_pb2 as wv_proto2
+from pywidevine.L1.cdm.session import Session
+from pywidevine.L1.cdm.key import Key
+from Cryptodome.Random import get_random_bytes
+from Cryptodome.Random import random
+from Cryptodome.Cipher import PKCS1_OAEP, AES
+from Cryptodome.Hash import CMAC, SHA256, HMAC, SHA1
+from Cryptodome.PublicKey import RSA
+from Cryptodome.Signature import pss
+from Cryptodome.Util import Padding
+import logging
+
+class Cdm:
+    def __init__(self):
+        self.logger = logging.getLogger(__name__)
+        self.sessions = {}
+
+    def open_session(self, init_data_b64, device, raw_init_data = None, offline=False):
+        self.logger.debug("open_session(init_data_b64={}, device={}".format(init_data_b64, device))
+        self.logger.info("opening new cdm session")
+        if device.session_id_type == 'android':
+            # format: 16 random hexdigits, 2 digit counter, 14 0s
+            rand_ascii = ''.join(random.choice('ABCDEF0123456789') for _ in range(16))
+            counter = '01' # this resets regularly so its fine to use 01
+            rest = '00000000000000'
+            session_id = rand_ascii + counter + rest
+            session_id = session_id.encode('ascii')
+        elif device.session_id_type == 'chrome':
+            rand_bytes = get_random_bytes(16)
+            session_id = rand_bytes
+        else:
+            # other formats NYI
+            self.logger.error("device type is unusable")
+            return 1
+        if raw_init_data and isinstance(raw_init_data, (bytes, bytearray)):
+            # used for NF key exchange, where they don't provide a valid PSSH
+            init_data = raw_init_data
+            self.raw_pssh = True
+        else:
+            init_data = self._parse_init_data(init_data_b64)
+            self.raw_pssh = False
+
+        if init_data:
+            new_session = Session(session_id, init_data, device, offline)
+        else:
+            self.logger.error("unable to parse init data")
+            return 1
+        self.sessions[session_id] = new_session
+        self.logger.info("session opened and init data parsed successfully")
+        return session_id
+
+    def _parse_init_data(self, init_data_b64):
+        parsed_init_data = wv_proto2.WidevineCencHeader()
+        try:
+            self.logger.debug("trying to parse init_data directly")
+            parsed_init_data.ParseFromString(base64.b64decode(init_data_b64)[32:])
+        except DecodeError:
+            self.logger.debug("unable to parse as-is, trying with removed pssh box header")
+            try:
+                id_bytes = parsed_init_data.ParseFromString(base64.b64decode(init_data_b64)[32:])
+            except DecodeError:
+                self.logger.error("unable to parse, unsupported init data format")
+                return None
+        self.logger.debug("init_data:")
+        for line in text_format.MessageToString(parsed_init_data).splitlines():
+            self.logger.debug(line)
+        return parsed_init_data
+
+    def close_session(self, session_id):
+        self.logger.debug("close_session(session_id={})".format(session_id))
+        self.logger.info("closing cdm session")
+        if session_id in self.sessions:
+            self.sessions.pop(session_id)
+            self.logger.info("cdm session closed")
+            return 0
+        else:
+            self.logger.info("session {} not found".format(session_id))
+            return 1
+
+    def set_service_certificate(self, session_id, cert_b64):
+        self.logger.debug("set_service_certificate(session_id={}, cert={})".format(session_id, cert_b64))
+        self.logger.info("setting service certificate")
+
+        if session_id not in self.sessions:
+            self.logger.error("session id doesn't exist")
+            return 1
+
+        session = self.sessions[session_id]
+
+        message = wv_proto2.SignedMessage()
+
+        try:
+            message.ParseFromString(base64.b64decode(cert_b64))
+        except DecodeError:
+            self.logger.error("failed to parse cert as SignedMessage")
+
+        service_certificate = wv_proto2.SignedDeviceCertificate()
+
+        if message.Type:
+            self.logger.debug("service cert provided as signedmessage")
+            try:
+                service_certificate.ParseFromString(message.Msg)
+            except DecodeError:
+                self.logger.error("failed to parse service certificate")
+                return 1
+        else:
+            self.logger.debug("service cert provided as signeddevicecertificate")
+            try:
+                service_certificate.ParseFromString(base64.b64decode(cert_b64))
+            except DecodeError:
+                self.logger.error("failed to parse service certificate")
+                return 1
+
+        self.logger.debug("service certificate:")
+        for line in text_format.MessageToString(service_certificate).splitlines():
+            self.logger.debug(line)
+
+        session.service_certificate = service_certificate
+        session.privacy_mode = True
+
+        return 0
+
+    def get_license_request(self, session_id):
+        self.logger.debug("get_license_request(session_id={})".format(session_id))
+        self.logger.info("getting license request")
+
+        if session_id not in self.sessions:
+            self.logger.error("session ID does not exist")
+            return 1
+
+        session = self.sessions[session_id]
+
+        # raw pssh will be treated as bytes and not parsed
+        if self.raw_pssh:
+            license_request = wv_proto2.SignedLicenseRequestRaw()
+        else:
+            license_request = wv_proto2.SignedLicenseRequest()
+        client_id = wv_proto2.ClientIdentification()
+
+        if not os.path.exists(session.device_config.device_client_id_blob_filename):
+            self.logger.error("no client ID blob available for this device")
+            return 1
+
+        with open(session.device_config.device_client_id_blob_filename, "rb") as f:
+            try:
+                cid_bytes = client_id.ParseFromString(f.read())
+            except DecodeError:
+                self.logger.error("client id failed to parse as protobuf")
+                return 1
+
+        self.logger.debug("building license request")
+        if not self.raw_pssh:
+            license_request.Type = wv_proto2.SignedLicenseRequest.MessageType.Value('LICENSE_REQUEST')
+            license_request.Msg.ContentId.CencId.Pssh.CopyFrom(session.init_data)
+        else:
+            license_request.Type = wv_proto2.SignedLicenseRequestRaw.MessageType.Value('LICENSE_REQUEST')
+            license_request.Msg.ContentId.CencId.Pssh = session.init_data # bytes
+
+        if session.offline:
+           license_type = wv_proto2.LicenseType.Value('OFFLINE')
+        else:
+           license_type = wv_proto2.LicenseType.Value('DEFAULT')
+        license_request.Msg.ContentId.CencId.LicenseType = license_type
+        license_request.Msg.ContentId.CencId.RequestId = session_id
+        license_request.Msg.Type = wv_proto2.LicenseRequest.RequestType.Value('NEW')
+        license_request.Msg.RequestTime = int(time.time())
+        license_request.Msg.ProtocolVersion = wv_proto2.ProtocolVersion.Value('CURRENT')
+        if session.device_config.send_key_control_nonce:
+            license_request.Msg.KeyControlNonce = random.randrange(1, 2**31)
+
+        if session.privacy_mode:
+            if session.device_config.vmp:
+                self.logger.debug("vmp required, adding to client_id")
+                self.logger.debug("reading vmp hashes")
+                vmp_hashes = wv_proto2.FileHashes()
+                with open(session.device_config.device_vmp_blob_filename, "rb") as f:
+                    try:
+                        vmp_bytes = vmp_hashes.ParseFromString(f.read())
+                    except DecodeError:
+                        self.logger.error("vmp hashes failed to parse as protobuf")
+                        return 1
+                client_id._FileHashes.CopyFrom(vmp_hashes)
+            self.logger.debug("privacy mode & service certificate loaded, encrypting client id")
+            self.logger.debug("unencrypted client id:")
+            for line in text_format.MessageToString(client_id).splitlines():
+                self.logger.debug(line)
+            cid_aes_key = get_random_bytes(16)
+            cid_iv = get_random_bytes(16)
+
+            cid_cipher = AES.new(cid_aes_key, AES.MODE_CBC, cid_iv)
+
+            encrypted_client_id = cid_cipher.encrypt(Padding.pad(client_id.SerializeToString(), 16))
+
+            service_public_key = RSA.importKey(session.service_certificate._DeviceCertificate.PublicKey)
+
+            service_cipher = PKCS1_OAEP.new(service_public_key)
+
+            encrypted_cid_key = service_cipher.encrypt(cid_aes_key)
+
+            encrypted_client_id_proto = wv_proto2.EncryptedClientIdentification()
+
+            encrypted_client_id_proto.ServiceId = session.service_certificate._DeviceCertificate.ServiceId
+            encrypted_client_id_proto.ServiceCertificateSerialNumber = session.service_certificate._DeviceCertificate.SerialNumber
+            encrypted_client_id_proto.EncryptedClientId = encrypted_client_id
+            encrypted_client_id_proto.EncryptedClientIdIv = cid_iv
+            encrypted_client_id_proto.EncryptedPrivacyKey = encrypted_cid_key
+
+            license_request.Msg.EncryptedClientId.CopyFrom(encrypted_client_id_proto)
+        else:
+            license_request.Msg.ClientId.CopyFrom(client_id)
+
+        if session.device_config.private_key_available:
+             key = RSA.importKey(open(session.device_config.device_private_key_filename).read())
+             session.device_key = key
+        else:
+             self.logger.error("need device private key, other methods unimplemented")
+             return 1
+
+        self.logger.debug("signing license request")
+
+        hash = SHA1.new(license_request.Msg.SerializeToString())
+        signature = pss.new(key).sign(hash)
+
+        license_request.Signature = signature
+
+        session.license_request = license_request
+
+        self.logger.debug("license request:")
+        for line in text_format.MessageToString(session.license_request).splitlines():
+            self.logger.debug(line)
+        self.logger.info("license request created")
+        self.logger.debug("license request b64: {}".format(base64.b64encode(license_request.SerializeToString())))
+        return license_request.SerializeToString()
+
+    def provide_license(self, session_id, license_b64):
+        self.logger.debug("provide_license(session_id={}, license_b64={})".format(session_id, license_b64))
+        self.logger.info("decrypting provided license")
+
+        if session_id not in self.sessions:
+            self.logger.error("session does not exist")
+            return 1
+
+        session = self.sessions[session_id]
+
+        if not session.license_request:
+            self.logger.error("generate a license request first!")
+            return 1
+
+        license = wv_proto2.SignedLicense()
+        try:
+            license.ParseFromString(base64.b64decode(license_b64))
+        except DecodeError:
+            self.logger.error("unable to parse license - check protobufs")
+            return 1
+
+        session.license = license
+
+        self.logger.debug("license:")
+        for line in text_format.MessageToString(license).splitlines():
+            self.logger.debug(line)
+
+        self.logger.debug("deriving keys from session key")
+
+        oaep_cipher = PKCS1_OAEP.new(session.device_key)
+
+        session.session_key = oaep_cipher.decrypt(license.SessionKey)
+
+        lic_req_msg = session.license_request.Msg.SerializeToString()
+
+        enc_key_base = b"ENCRYPTION\000" + lic_req_msg + b"\0\0\0\x80"
+        auth_key_base = b"AUTHENTICATION\0" + lic_req_msg + b"\0\0\2\0"
+
+        enc_key = b"\x01" + enc_key_base
+        auth_key_1 = b"\x01" + auth_key_base
+        auth_key_2 = b"\x02" + auth_key_base
+        auth_key_3 = b"\x03" + auth_key_base
+        auth_key_4 = b"\x04" + auth_key_base
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(enc_key)
+
+        enc_cmac_key = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_1)
+        auth_cmac_key_1 = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_2)
+        auth_cmac_key_2 = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_3)
+        auth_cmac_key_3 = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_4)
+        auth_cmac_key_4 = cmac_obj.digest()
+
+        auth_cmac_combined_1 = auth_cmac_key_1 + auth_cmac_key_2
+        auth_cmac_combined_2 = auth_cmac_key_3 + auth_cmac_key_4
+
+        session.derived_keys['enc'] = enc_cmac_key
+        session.derived_keys['auth_1'] = auth_cmac_combined_1
+        session.derived_keys['auth_2'] = auth_cmac_combined_2
+
+        self.logger.debug('verifying license signature')
+
+        lic_hmac = HMAC.new(session.derived_keys['auth_1'], digestmod=SHA256)
+        lic_hmac.update(license.Msg.SerializeToString())
+
+        self.logger.debug("calculated sig: {} actual sig: {}".format(lic_hmac.hexdigest(), binascii.hexlify(license.Signature)))
+
+        if lic_hmac.digest() != license.Signature:
+            self.logger.info("license signature doesn't match - writing bin so they can be debugged")
+            with open("original_lic.bin", "wb") as f:
+                f.write(base64.b64decode(license_b64))
+            with open("parsed_lic.bin", "wb") as f:
+                f.write(license.SerializeToString())
+            self.logger.info("continuing anyway")
+
+        self.logger.debug("key count: {}".format(len(license.Msg.Key)))
+        for key in license.Msg.Key:
+            if key.Id:
+                key_id = key.Id
+            else:
+                key_id = wv_proto2.License.KeyContainer.KeyType.Name(key.Type).encode('utf-8')
+            encrypted_key = key.Key
+            iv = key.Iv
+            type = wv_proto2.License.KeyContainer.KeyType.Name(key.Type)
+
+            cipher = AES.new(session.derived_keys['enc'], AES.MODE_CBC, iv=iv)
+            decrypted_key = cipher.decrypt(encrypted_key)
+            if type == "OPERATOR_SESSION":
+                permissions = []
+                perms = key._OperatorSessionKeyPermissions
+                for (descriptor, value) in perms.ListFields():
+                    if value == 1:
+                        permissions.append(descriptor.name)
+                print(permissions)
+            else:
+                permissions = []
+            session.keys.append(Key(key_id, type, Padding.unpad(decrypted_key, 16), permissions))
+
+        self.logger.info("decrypted all keys")
+        return 0
+
+    def get_keys(self, session_id):
+        if session_id in self.sessions:
+            return self.sessions[session_id].keys
+        else:
+            self.logger.error("session not found")
+            return 1
--- a/pywidevine/L1/cdm/deviceconfig.py
+++ b/pywidevine/L1/cdm/deviceconfig.py
@ -0,0 +1,53 @@
+import os
+
+device_android_generic = {
+    'name': 'android_generic',
+    'description': 'android studio cdm',
+    'security_level': 1,
+    'session_id_type': 'android',
+    'private_key_available': True,
+    'vmp': False,
+    'send_key_control_nonce': True
+}
+
+devices_available = [device_android_generic]
+
+FILES_FOLDER = 'devices'
+
+class DeviceConfig:
+    def __init__(self, device):
+        self.device_name = device['name']
+        self.description = device['description']
+        self.security_level = device['security_level']
+        self.session_id_type = device['session_id_type']
+        self.private_key_available = device['private_key_available']
+        self.vmp = device['vmp']
+        self.send_key_control_nonce = device['send_key_control_nonce']
+
+        if 'keybox_filename' in device:
+            self.keybox_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['keybox_filename'])
+        else:
+            self.keybox_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'keybox')
+
+        if 'device_cert_filename' in device:
+            self.device_cert_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_cert_filename'])
+        else:
+            self.device_cert_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_cert')
+
+        if 'device_private_key_filename' in device:
+            self.device_private_key_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_private_key_filename'])
+        else:
+            self.device_private_key_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_private_key')
+
+        if 'device_client_id_blob_filename' in device:
+            self.device_client_id_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_client_id_blob_filename'])
+        else:
+            self.device_client_id_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_client_id_blob')
+
+        if 'device_vmp_blob_filename' in device:
+            self.device_vmp_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_vmp_blob_filename'])
+        else:
+            self.device_vmp_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_vmp_blob')
+
+    def __repr__(self):
+        return "DeviceConfig(name={}, description={}, security_level={}, session_id_type={}, private_key_available={}, vmp={})".format(self.device_name, self.description, self.security_level, self.session_id_type, self.private_key_available, self.vmp)
--- a/pywidevine/L1/cdm/formats/init.py
+++ b/pywidevine/L1/cdm/formats/init.py
--- a/pywidevine/L1/cdm/formats/pycache/init.cpython-37.pyc
+++ b/pywidevine/L1/cdm/formats/pycache/init.cpython-37.pyc
--- a/pywidevine/L1/cdm/formats/pycache/wv_proto2_pb2.cpython-37.pyc
+++ b/pywidevine/L1/cdm/formats/pycache/wv_proto2_pb2.cpython-37.pyc
--- a/pywidevine/L1/cdm/formats/wv_proto2.proto
+++ b/pywidevine/L1/cdm/formats/wv_proto2.proto
@ -0,0 +1,466 @@
+syntax = "proto2";
+
+// from x86 (partial), most of it from the ARM version:
+message ClientIdentification {
+    enum TokenType {
+        KEYBOX = 0;
+        DEVICE_CERTIFICATE = 1;
+        REMOTE_ATTESTATION_CERTIFICATE = 2;
+    }
+    message NameValue {
+        required string Name = 1;
+        required string Value = 2;
+    }
+    message ClientCapabilities {
+        enum HdcpVersion {
+            HDCP_NONE = 0;
+            HDCP_V1 = 1;
+            HDCP_V2 = 2;
+            HDCP_V2_1 = 3;
+            HDCP_V2_2 = 4;
+        }
+        optional uint32 ClientToken = 1;
+        optional uint32 SessionToken = 2;
+        optional uint32 VideoResolutionConstraints = 3;
+        optional HdcpVersion MaxHdcpVersion = 4;
+        optional uint32 OemCryptoApiVersion = 5;
+    }
+    required TokenType Type = 1;
+    //optional bytes Token = 2; // by default the client treats this as blob, but it's usually a DeviceCertificate, so for usefulness sake, I'm replacing it with this one:
+    optional SignedDeviceCertificate Token = 2; // use this when parsing, "bytes" when building a client id blob
+    repeated NameValue ClientInfo = 3;
+    optional bytes ProviderClientToken = 4;
+    optional uint32 LicenseCounter = 5;
+    optional ClientCapabilities _ClientCapabilities = 6; // how should we deal with duped names? will have to look at proto docs later
+    optional FileHashes _FileHashes = 7; // vmp blob goes here
+}
+
+message DeviceCertificate {
+    enum CertificateType {
+        ROOT = 0;
+        INTERMEDIATE = 1;
+        USER_DEVICE = 2;
+        SERVICE = 3;
+    }
+    required CertificateType Type = 1; // the compiled code reused this as ProvisionedDeviceInfo.WvSecurityLevel, however that is incorrect (compiler aliased it as they're both identical as a structure)
+    optional bytes SerialNumber = 2;
+    optional uint32 CreationTimeSeconds = 3;
+    optional bytes PublicKey = 4;
+    optional uint32 SystemId = 5;
+    optional uint32 TestDeviceDeprecated = 6; // is it bool or int?
+    optional bytes ServiceId = 7; // service URL for service certificates
+}
+
+// missing some references,
+message DeviceCertificateStatus {
+    enum CertificateStatus {
+        VALID = 0;
+        REVOKED = 1;
+    }
+    optional bytes SerialNumber = 1;
+    optional CertificateStatus Status = 2;
+    optional ProvisionedDeviceInfo DeviceInfo = 4; // where is 3? is it deprecated?
+}
+
+message DeviceCertificateStatusList {
+    optional uint32 CreationTimeSeconds = 1;
+    repeated DeviceCertificateStatus CertificateStatus = 2;
+}
+
+message EncryptedClientIdentification {
+    required string ServiceId = 1;
+    optional bytes ServiceCertificateSerialNumber = 2;
+    required bytes EncryptedClientId = 3;
+    required bytes EncryptedClientIdIv = 4;
+    required bytes EncryptedPrivacyKey = 5;
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+enum LicenseType {
+    ZERO = 0;
+    DEFAULT = 1; // 1 is STREAMING/temporary license; on recent versions may go up to 3 (latest x86); it might be persist/don't persist type, unconfirmed
+    OFFLINE = 2;
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+// this is just a guess because these globals got lost, but really, do we need more?
+enum ProtocolVersion {
+    CURRENT = 21; // don't have symbols for this
+}
+
+
+message LicenseIdentification {
+    optional bytes RequestId = 1;
+    optional bytes SessionId = 2;
+    optional bytes PurchaseId = 3;
+    optional LicenseType Type = 4;
+    optional uint32 Version = 5;
+    optional bytes ProviderSessionToken = 6;
+}
+
+
+message License {
+    message Policy {
+        optional bool CanPlay = 1; // changed from uint32 to bool
+        optional bool CanPersist = 2;
+        optional bool CanRenew = 3;
+        optional uint32 RentalDurationSeconds = 4;
+        optional uint32 PlaybackDurationSeconds = 5;
+        optional uint32 LicenseDurationSeconds = 6;
+        optional uint32 RenewalRecoveryDurationSeconds = 7;
+        optional string RenewalServerUrl = 8;
+        optional uint32 RenewalDelaySeconds = 9;
+        optional uint32 RenewalRetryIntervalSeconds = 10;
+        optional bool RenewWithUsage = 11; // was uint32
+    }
+    message KeyContainer {
+        enum KeyType {
+            SIGNING = 1;
+            CONTENT = 2;
+            KEY_CONTROL = 3;
+            OPERATOR_SESSION = 4;
+        }
+        enum SecurityLevel {
+            SW_SECURE_CRYPTO = 1;
+            SW_SECURE_DECODE = 2;
+            HW_SECURE_CRYPTO = 3;
+            HW_SECURE_DECODE = 4;
+            HW_SECURE_ALL = 5;
+        }
+        message OutputProtection {
+            enum CGMS {
+                COPY_FREE = 0;
+                COPY_ONCE = 2;
+                COPY_NEVER = 3;
+                CGMS_NONE = 0x2A; // PC default!
+            }
+            optional ClientIdentification.ClientCapabilities.HdcpVersion Hdcp = 1; // it's most likely a copy of Hdcp version available here, but compiler optimized it away
+            optional CGMS CgmsFlags = 2;
+        }
+        message KeyControl {
+            required bytes KeyControlBlock = 1; // what is this?
+            required bytes Iv = 2;
+        }
+        message OperatorSessionKeyPermissions {
+            optional uint32 AllowEncrypt = 1;
+            optional uint32 AllowDecrypt = 2;
+            optional uint32 AllowSign = 3;
+            optional uint32 AllowSignatureVerify = 4;
+        }
+        message VideoResolutionConstraint {
+            optional uint32 MinResolutionPixels = 1;
+            optional uint32 MaxResolutionPixels = 2;
+            optional OutputProtection RequiredProtection = 3;
+        }
+        optional bytes Id = 1;
+        optional bytes Iv = 2;
+        optional bytes Key = 3;
+        optional KeyType Type = 4;
+        optional SecurityLevel Level = 5;
+        optional OutputProtection RequiredProtection = 6;
+        optional OutputProtection RequestedProtection = 7;
+        optional KeyControl _KeyControl = 8; // duped names, etc
+        optional OperatorSessionKeyPermissions _OperatorSessionKeyPermissions = 9; // duped names, etc
+        repeated VideoResolutionConstraint VideoResolutionConstraints = 10;
+    }
+    optional LicenseIdentification Id = 1;
+    optional Policy _Policy = 2; // duped names, etc
+    repeated KeyContainer Key = 3;
+    optional uint32 LicenseStartTime = 4;
+    optional uint32 RemoteAttestationVerified = 5; // bool?
+    optional bytes ProviderClientToken = 6;
+    // there might be more, check with newer versions (I see field 7-8 in a lic)
+    // this appeared in latest x86:
+    optional uint32 ProtectionScheme = 7; // type unconfirmed fully, but it's likely as WidevineCencHeader describesit (fourcc)
+}
+
+message LicenseError {
+    enum Error {
+        INVALID_DEVICE_CERTIFICATE = 1;
+        REVOKED_DEVICE_CERTIFICATE = 2;
+        SERVICE_UNAVAILABLE = 3;
+    }
+    //LicenseRequest.RequestType ErrorCode; // clang mismatch
+    optional Error ErrorCode = 1;
+}
+
+message LicenseRequest {
+    message ContentIdentification {
+        message CENC {
+            //optional bytes Pssh = 1; // the client's definition is opaque, it doesn't care about the contents, but the PSSH has a clear definition that is understood and requested by the server, thus I'll replace it with:
+            optional WidevineCencHeader Pssh = 1;
+            optional LicenseType LicenseType = 2; // unfortunately the LicenseType symbols are not present, acceptable value seems to only be 1 (is this persist/don't persist? look into it!)
+            optional bytes RequestId = 3;
+        }
+        message WebM {
+            optional bytes Header = 1; // identical to CENC, aside from PSSH and the parent field number used
+            optional LicenseType LicenseType = 2;
+            optional bytes RequestId = 3;
+        }
+        message ExistingLicense {
+            optional LicenseIdentification LicenseId = 1;
+            optional uint32 SecondsSinceStarted = 2;
+            optional uint32 SecondsSinceLastPlayed = 3;
+            optional bytes SessionUsageTableEntry = 4; // interesting! try to figure out the connection between the usage table blob and KCB!
+        }
+        optional CENC CencId = 1;
+        optional WebM WebmId = 2;
+        optional ExistingLicense License = 3;
+    }
+    enum RequestType {
+        NEW = 1;
+        RENEWAL = 2;
+        RELEASE = 3;
+    }
+    optional ClientIdentification ClientId = 1;
+    optional ContentIdentification ContentId = 2;
+    optional RequestType Type = 3;
+    optional uint32 RequestTime = 4;
+    optional bytes KeyControlNonceDeprecated = 5;
+    optional ProtocolVersion ProtocolVersion = 6; // lacking symbols for this
+    optional uint32 KeyControlNonce = 7;
+    optional EncryptedClientIdentification EncryptedClientId = 8;
+}
+
+// raw pssh hack
+message LicenseRequestRaw {
+    message ContentIdentification {
+        message CENC {
+            optional bytes Pssh = 1; // the client's definition is opaque, it doesn't care about the contents, but the PSSH has a clear definition that is understood and requested by the server, thus I'll replace it with:
+            //optional WidevineCencHeader Pssh = 1;
+            optional LicenseType LicenseType = 2; // unfortunately the LicenseType symbols are not present, acceptable value seems to only be 1 (is this persist/don't persist? look into it!)
+            optional bytes RequestId = 3;
+        }
+        message WebM {
+            optional bytes Header = 1; // identical to CENC, aside from PSSH and the parent field number used
+            optional LicenseType LicenseType = 2;
+            optional bytes RequestId = 3;
+        }
+        message ExistingLicense {
+            optional LicenseIdentification LicenseId = 1;
+            optional uint32 SecondsSinceStarted = 2;
+            optional uint32 SecondsSinceLastPlayed = 3;
+            optional bytes SessionUsageTableEntry = 4; // interesting! try to figure out the connection between the usage table blob and KCB!
+        }
+        optional CENC CencId = 1;
+        optional WebM WebmId = 2;
+        optional ExistingLicense License = 3;
+    }
+    enum RequestType {
+        NEW = 1;
+        RENEWAL = 2;
+        RELEASE = 3;
+    }
+    optional ClientIdentification ClientId = 1;
+    optional ContentIdentification ContentId = 2;
+    optional RequestType Type = 3;
+    optional uint32 RequestTime = 4;
+    optional bytes KeyControlNonceDeprecated = 5;
+    optional ProtocolVersion ProtocolVersion = 6; // lacking symbols for this
+    optional uint32 KeyControlNonce = 7;
+    optional EncryptedClientIdentification EncryptedClientId = 8;
+}
+
+
+message ProvisionedDeviceInfo {
+    enum WvSecurityLevel {
+        LEVEL_UNSPECIFIED = 0;
+        LEVEL_1 = 1;
+        LEVEL_2 = 2;
+        LEVEL_3 = 3;
+    }
+    optional uint32 SystemId = 1;
+    optional string Soc = 2;
+    optional string Manufacturer = 3;
+    optional string Model = 4;
+    optional string DeviceType = 5;
+    optional uint32 ModelYear = 6;
+    optional WvSecurityLevel SecurityLevel = 7;
+    optional uint32 TestDevice = 8; // bool?
+}
+
+
+// todo: fill
+message ProvisioningOptions {
+}
+
+// todo: fill
+message ProvisioningRequest {
+}
+
+// todo: fill
+message ProvisioningResponse {
+}
+
+message RemoteAttestation {
+    optional EncryptedClientIdentification Certificate = 1;
+    optional string Salt = 2;
+    optional string Signature = 3;
+}
+
+// todo: fill
+message SessionInit {
+}
+
+// todo: fill
+message SessionState {
+}
+
+// todo: fill
+message SignedCertificateStatusList {
+}
+
+message SignedDeviceCertificate {
+
+    //optional bytes DeviceCertificate = 1; // again, they use a buffer where it's supposed to be a message, so we'll replace it with what it really is:
+    optional DeviceCertificate _DeviceCertificate = 1; // how should we deal with duped names? will have to look at proto docs later
+    optional bytes Signature = 2;
+    optional SignedDeviceCertificate Signer = 3;
+}
+
+
+// todo: fill
+message SignedProvisioningMessage {
+}
+
+// the root of all messages, from either server or client
+message SignedMessage {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional bytes Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+
+
+// This message is copied from google's docs, not reversed:
+message WidevineCencHeader {
+    enum Algorithm {
+        UNENCRYPTED = 0;
+        AESCTR = 1;
+    };
+    optional Algorithm algorithm = 1;
+    repeated bytes key_id = 2;
+
+    // Content provider name.
+    optional string provider = 3;
+
+    // A content identifier, specified by content provider.
+    optional bytes content_id = 4;
+
+    // Track type. Acceptable values are SD, HD and AUDIO. Used to
+    // differentiate content keys used by an asset.
+    optional string track_type_deprecated = 5;
+
+    // The name of a registered policy to be used for this asset.
+    optional string policy = 6;
+
+    // Crypto period index, for media using key rotation.
+    optional uint32 crypto_period_index = 7;
+
+    // Optional protected context for group content. The grouped_license is a
+    // serialized SignedMessage.
+    optional bytes grouped_license = 8;
+
+    // Protection scheme identifying the encryption algorithm.
+    // Represented as one of the following 4CC values:
+    // 'cenc' (AESCTR), 'cbc1' (AESCBC),
+    // 'cens' (AESCTR subsample), 'cbcs' (AESCBC subsample).
+    optional uint32 protection_scheme = 9;
+
+    // Optional. For media using key rotation, this represents the duration
+    // of each crypto period in seconds.
+    optional uint32 crypto_period_seconds = 10;
+}
+
+
+// remove these when using it outside of protoc:
+
+// from here on, it's just for testing, these messages don't exist in the binaries, I'm adding them to avoid detecting type programmatically
+message SignedLicenseRequest {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional LicenseRequest Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+// hack
+message SignedLicenseRequestRaw {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional LicenseRequestRaw Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+
+message SignedLicense {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional License Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+message SignedServiceCertificate {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional SignedDeviceCertificate Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+//vmp support
+message FileHashes {
+   message Signature {
+     optional string filename = 1;
+     optional bool test_signing = 2; //0 - release, 1 - testing
+     optional bytes SHA512Hash = 3;
+     optional bool main_exe = 4; //0 for dlls, 1 for exe, this is field 3 in file
+     optional bytes signature = 5;
+   }
+   optional bytes signer = 1;
+   repeated Signature signatures = 2;
+}
--- a/pywidevine/L1/cdm/formats/wv_proto2_pb2.py
+++ b/pywidevine/L1/cdm/formats/wv_proto2_pb2.py
--- a/pywidevine/L1/cdm/formats/wv_proto3.proto
+++ b/pywidevine/L1/cdm/formats/wv_proto3.proto
@ -0,0 +1,389 @@
+// beware proto3 won't show missing fields it seems, need to change to "proto2" and add "optional" before every field, and remove all the dummy enum members I added:
+syntax = "proto3";
+
+// from x86 (partial), most of it from the ARM version:
+message ClientIdentification {
+  enum TokenType {
+    KEYBOX = 0;
+    DEVICE_CERTIFICATE = 1;
+    REMOTE_ATTESTATION_CERTIFICATE = 2;
+  }
+  message NameValue {
+    string Name = 1;
+    string Value = 2;
+  }
+  message ClientCapabilities {
+    enum HdcpVersion {
+      HDCP_NONE = 0;
+      HDCP_V1 = 1;
+      HDCP_V2 = 2;
+      HDCP_V2_1 = 3;
+      HDCP_V2_2 = 4;
+    }
+    uint32 ClientToken = 1;
+    uint32 SessionToken = 2;
+    uint32 VideoResolutionConstraints = 3;
+    HdcpVersion MaxHdcpVersion = 4;
+    uint32 OemCryptoApiVersion = 5;
+  }
+  TokenType Type = 1;
+  //bytes Token = 2; // by default the client treats this as blob, but it's usually a DeviceCertificate, so for usefulness sake, I'm replacing it with this one:
+  SignedDeviceCertificate Token = 2; 
+  repeated NameValue ClientInfo = 3;
+  bytes ProviderClientToken = 4;
+  uint32 LicenseCounter = 5;
+  ClientCapabilities _ClientCapabilities = 6; // how should we deal with duped names? will have to look at proto docs later
+}
+
+message DeviceCertificate {
+  enum CertificateType {
+    ROOT = 0;
+    INTERMEDIATE = 1;
+    USER_DEVICE = 2;
+    SERVICE = 3;
+  }
+  //ProvisionedDeviceInfo.WvSecurityLevel Type = 1; // is this how one is supposed to call it? (it's an enum) there might be a bug here, with CertificateType getting confused with WvSecurityLevel, for now renaming it (verify against other binaries)
+  CertificateType Type = 1;
+  bytes SerialNumber = 2; 
+  uint32 CreationTimeSeconds = 3;
+  bytes PublicKey = 4;
+  uint32 SystemId = 5;
+  uint32 TestDeviceDeprecated = 6; // is it bool or int?
+  bytes ServiceId = 7; // service URL for service certificates
+}
+
+// missing some references, 
+message DeviceCertificateStatus {
+  enum CertificateStatus {
+    VALID = 0;
+    REVOKED = 1;
+  }
+  bytes SerialNumber = 1;
+  CertificateStatus Status = 2; 
+  ProvisionedDeviceInfo DeviceInfo = 4; // where is 3? is it deprecated?
+}
+
+message DeviceCertificateStatusList {
+  uint32 CreationTimeSeconds = 1;
+  repeated DeviceCertificateStatus CertificateStatus = 2;
+}
+
+message EncryptedClientIdentification {
+  string ServiceId = 1;
+  bytes ServiceCertificateSerialNumber = 2;
+  bytes EncryptedClientId = 3;
+  bytes EncryptedClientIdIv = 4;
+  bytes EncryptedPrivacyKey = 5;
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+enum LicenseType {
+  ZERO = 0;
+  DEFAULT = 1; // do not know what this is either, but should be 1; on recent versions may go up to 3 (latest x86)
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+// this is just a guess because these globals got lost, but really, do we need more? 
+enum ProtocolVersion {
+  DUMMY = 0;
+  CURRENT = 21; // don't have symbols for this
+}
+
+
+message LicenseIdentification {
+  bytes RequestId = 1;
+  bytes SessionId = 2;
+  bytes PurchaseId = 3;
+  LicenseType Type = 4;
+  uint32 Version = 5;
+  bytes ProviderSessionToken = 6;
+}
+
+
+message License {
+  message Policy {
+    uint32 CanPlay = 1;
+    uint32 CanPersist = 2;
+    uint32 CanRenew = 3;
+    uint32 RentalDurationSeconds = 4;
+    uint32 PlaybackDurationSeconds = 5;
+    uint32 LicenseDurationSeconds = 6;
+    uint32 RenewalRecoveryDurationSeconds = 7;
+    string RenewalServerUrl = 8;
+    uint32 RenewalDelaySeconds = 9;
+    uint32 RenewalRetryIntervalSeconds = 10;
+    uint32 RenewWithUsage = 11;
+	uint32 UnknownPolicy12 = 12;
+  }
+  message KeyContainer {
+    enum KeyType {
+      _NOKEYTYPE = 0; // dummy, added to satisfy proto3, not present in original
+      SIGNING = 1;
+      CONTENT = 2;
+      KEY_CONTROL = 3;
+      OPERATOR_SESSION = 4;
+    }
+    enum SecurityLevel {
+      _NOSECLEVEL = 0; // dummy, added to satisfy proto3, not present in original
+      SW_SECURE_CRYPTO = 1;
+      SW_SECURE_DECODE = 2;
+      HW_SECURE_CRYPTO = 3;
+      HW_SECURE_DECODE = 4;
+      HW_SECURE_ALL = 5;
+    }
+    message OutputProtection {
+      enum CGMS {
+        COPY_FREE = 0;
+        COPY_ONCE = 2;
+        COPY_NEVER = 3;
+        CGMS_NONE = 0x2A; // PC default!
+      }
+      ClientIdentification.ClientCapabilities.HdcpVersion Hdcp = 1; // it's most likely a copy of Hdcp version available here, but compiler optimized it away
+      CGMS CgmsFlags = 2;
+    }
+    message KeyControl {
+      bytes KeyControlBlock = 1; // what is this?
+      bytes Iv = 2;
+    }
+    message OperatorSessionKeyPermissions {
+      uint32 AllowEncrypt = 1;
+      uint32 AllowDecrypt = 2;
+      uint32 AllowSign = 3;
+      uint32 AllowSignatureVerify = 4;
+    }
+    message VideoResolutionConstraint {
+      uint32 MinResolutionPixels = 1;
+      uint32 MaxResolutionPixels = 2;
+      OutputProtection RequiredProtection = 3;
+    }
+    bytes Id = 1;
+    bytes Iv = 2;
+    bytes Key = 3;
+    KeyType Type = 4;
+    SecurityLevel Level = 5;
+    OutputProtection RequiredProtection = 6;
+    OutputProtection RequestedProtection = 7;
+    KeyControl _KeyControl = 8; // duped names, etc
+    OperatorSessionKeyPermissions _OperatorSessionKeyPermissions = 9; // duped names, etc
+    repeated VideoResolutionConstraint VideoResolutionConstraints = 10;
+  }
+  LicenseIdentification Id = 1;
+  Policy _Policy = 2; // duped names, etc
+  repeated KeyContainer Key = 3;
+  uint32 LicenseStartTime = 4;
+  uint32 RemoteAttestationVerified = 5; // bool?
+  bytes ProviderClientToken = 6;
+  // there might be more, check with newer versions (I see field 7-8 in a lic)
+  // this appeared in latest x86:
+  uint32 ProtectionScheme = 7; // type unconfirmed fully, but it's likely as WidevineCencHeader describesit (fourcc)
+  bytes UnknownHdcpDataField = 8;
+}
+
+message LicenseError {
+  enum Error {
+    DUMMY_NO_ERROR = 0; // dummy, added to satisfy proto3
+    INVALID_DEVICE_CERTIFICATE = 1;
+    REVOKED_DEVICE_CERTIFICATE = 2;
+    SERVICE_UNAVAILABLE = 3;
+  }
+  //LicenseRequest.RequestType ErrorCode; // clang mismatch
+  Error ErrorCode = 1;
+}
+
+message LicenseRequest {
+  message ContentIdentification {
+    message CENC {
+      // bytes Pssh = 1; // the client's definition is opaque, it doesn't care about the contents, but the PSSH has a clear definition that is understood and requested by the server, thus I'll replace it with:
+      WidevineCencHeader Pssh = 1;
+      LicenseType LicenseType = 2; // unfortunately the LicenseType symbols are not present, acceptable value seems to only be 1
+      bytes RequestId = 3;
+    }
+    message WebM {
+      bytes Header = 1; // identical to CENC, aside from PSSH and the parent field number used
+      LicenseType LicenseType = 2;
+      bytes RequestId = 3;
+    }
+    message ExistingLicense {
+      LicenseIdentification LicenseId = 1;
+      uint32 SecondsSinceStarted = 2;
+      uint32 SecondsSinceLastPlayed = 3;
+      bytes SessionUsageTableEntry = 4;
+    }
+    CENC CencId = 1;
+    WebM WebmId = 2;
+    ExistingLicense License = 3;
+  }
+  enum RequestType {
+    DUMMY_REQ_TYPE = 0; // dummy, added to satisfy proto3
+    NEW = 1;
+    RENEWAL = 2;
+    RELEASE = 3;
+  }   
+  ClientIdentification ClientId = 1;
+  ContentIdentification ContentId = 2;
+  RequestType Type = 3;
+  uint32 RequestTime = 4;
+  bytes KeyControlNonceDeprecated = 5;
+  ProtocolVersion ProtocolVersion = 6; // lacking symbols for this
+  uint32 KeyControlNonce = 7;
+  EncryptedClientIdentification EncryptedClientId = 8;
+}
+
+message ProvisionedDeviceInfo {
+  enum WvSecurityLevel {
+    LEVEL_UNSPECIFIED = 0;
+    LEVEL_1 = 1;
+    LEVEL_2 = 2;
+    LEVEL_3 = 3;
+  }
+  uint32 SystemId = 1;
+  string Soc = 2;
+  string Manufacturer = 3;
+  string Model = 4;
+  string DeviceType = 5;
+  uint32 ModelYear = 6;
+  WvSecurityLevel SecurityLevel = 7;
+  uint32 TestDevice = 8; // bool?
+} 
+
+
+// todo: fill
+message ProvisioningOptions {
+}
+
+// todo: fill
+message ProvisioningRequest {
+}
+
+// todo: fill
+message ProvisioningResponse {
+}
+
+message RemoteAttestation {
+  EncryptedClientIdentification Certificate = 1;
+  string Salt = 2;
+  string Signature = 3;
+}
+
+// todo: fill
+message SessionInit {
+}
+
+// todo: fill
+message SessionState {
+}
+
+// todo: fill
+message SignedCertificateStatusList {
+}
+
+message SignedDeviceCertificate {
+  
+  //bytes DeviceCertificate = 1; // again, they use a buffer where it's supposed to be a message, so we'll replace it with what it really is:
+  DeviceCertificate _DeviceCertificate = 1; // how should we deal with duped names? will have to look at proto docs later
+  bytes Signature = 2;
+  SignedDeviceCertificate Signer = 3;
+}
+
+
+// todo: fill
+message SignedProvisioningMessage {
+}
+
+// the root of all messages, from either server or client
+message SignedMessage {
+  enum MessageType {
+    DUMMY_MSG_TYPE = 0; // dummy, added to satisfy proto3
+    LICENSE_REQUEST = 1;
+    LICENSE = 2;
+    ERROR_RESPONSE = 3;
+    SERVICE_CERTIFICATE_REQUEST = 4;
+    SERVICE_CERTIFICATE = 5;
+  }
+  MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+  bytes Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+                 // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+  bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+  bytes SessionKey = 4; // often RSA wrapped for licenses
+  RemoteAttestation RemoteAttestation = 5;
+}
+
+
+
+// This message is copied from google's docs, not reversed:
+message WidevineCencHeader {
+  enum Algorithm {
+    UNENCRYPTED = 0;
+    AESCTR = 1;
+  };
+  Algorithm algorithm = 1;
+  repeated bytes key_id = 2;
+
+  // Content provider name.
+  string provider = 3;
+
+  // A content identifier, specified by content provider.
+  bytes content_id = 4;
+
+  // Track type. Acceptable values are SD, HD and AUDIO. Used to
+  // differentiate content keys used by an asset.
+  string track_type_deprecated = 5;
+
+  // The name of a registered policy to be used for this asset.
+  string policy = 6;
+
+  // Crypto period index, for media using key rotation.
+  uint32 crypto_period_index = 7;
+
+  // Optional protected context for group content. The grouped_license is a
+  // serialized SignedMessage.
+  bytes grouped_license = 8;
+
+  // Protection scheme identifying the encryption algorithm.
+  // Represented as one of the following 4CC values:
+  // 'cenc' (AESCTR), 'cbc1' (AESCBC),
+  // 'cens' (AESCTR subsample), 'cbcs' (AESCBC subsample).
+  uint32 protection_scheme = 9;
+
+  // Optional. For media using key rotation, this represents the duration
+  // of each crypto period in seconds.
+  uint32 crypto_period_seconds = 10;
+}
+
+
+
+
+// from here on, it's just for testing, these messages don't exist in the binaries, I'm adding them to avoid detecting type programmatically
+message SignedLicenseRequest {
+  enum MessageType {
+    DUMMY_MSG_TYPE = 0; // dummy, added to satisfy proto3
+    LICENSE_REQUEST = 1;
+    LICENSE = 2;
+    ERROR_RESPONSE = 3;
+    SERVICE_CERTIFICATE_REQUEST = 4;
+    SERVICE_CERTIFICATE = 5;
+  }
+  MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+  LicenseRequest Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+                 // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+  bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+  bytes SessionKey = 4; // often RSA wrapped for licenses
+  RemoteAttestation RemoteAttestation = 5;
+}
+
+message SignedLicense {
+  enum MessageType {
+    DUMMY_MSG_TYPE = 0; // dummy, added to satisfy proto3
+    LICENSE_REQUEST = 1;
+    LICENSE = 2;
+    ERROR_RESPONSE = 3;
+    SERVICE_CERTIFICATE_REQUEST = 4;
+    SERVICE_CERTIFICATE = 5;
+  }
+  MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+  License Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+                 // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+  bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+  bytes SessionKey = 4; // often RSA wrapped for licenses
+  RemoteAttestation RemoteAttestation = 5;
+}
--- a/pywidevine/L1/cdm/formats/wv_proto3_pb2.py
+++ b/pywidevine/L1/cdm/formats/wv_proto3_pb2.py
--- a/pywidevine/L1/cdm/key.py
+++ b/pywidevine/L1/cdm/key.py
@ -0,0 +1,14 @@
+import binascii
+
+class Key:
+    def __init__(self, kid, type, key, permissions=[]):
+        self.kid = kid
+        self.type = type
+        self.key = key
+        self.permissions = permissions
+
+    def __repr__(self):
+        if self.type == "OPERATOR_SESSION":
+           return "key(kid={}, type={}, key={}, permissions={})".format(self.kid, self.type, binascii.hexlify(self.key), self.permissions)
+        else:
+           return "key(kid={}, type={}, key={})".format(self.kid, self.type, binascii.hexlify(self.key))
--- a/pywidevine/L1/cdm/session.py
+++ b/pywidevine/L1/cdm/session.py
@ -0,0 +1,18 @@
+class Session:
+    def __init__(self, session_id, init_data, device_config, offline):
+        self.session_id = session_id
+        self.init_data = init_data
+        self.offline = offline
+        self.device_config = device_config
+        self.device_key = None
+        self.session_key = None
+        self.derived_keys = {
+            'enc': None,
+            'auth_1': None,
+            'auth_2': None
+        }
+        self.license_request = None
+        self.license = None
+        self.service_certificate = None
+        self.privacy_mode = False
+        self.keys = []
--- a/pywidevine/L1/cdm/vmp.py
+++ b/pywidevine/L1/cdm/vmp.py
@ -0,0 +1,102 @@
+try:
+  from google.protobuf.internal.decoder import _DecodeVarint as _di # this was tested to work with protobuf 3, but it's an internal API (any varint decoder might work)
+except ImportError:
+  # this is generic and does not depend on pb internals, however it will decode "larger" possible numbers than pb decoder which has them fixed
+  def LEB128_decode(buffer, pos, limit = 64):
+    result = 0
+    shift = 0
+    while True:
+      b = buffer[pos]
+      pos += 1  
+      result |= ((b & 0x7F) << shift)
+      if not (b & 0x80): 
+         return (result, pos)
+      shift += 7
+      if shift > limit: 
+         raise Exception("integer too large, shift: {}".format(shift))
+  _di = LEB128_decode
+
+
+class FromFileMixin:
+  @classmethod
+  def from_file(cls, filename):
+    """Load given a filename"""
+    with open(filename,"rb") as f:
+      return cls(f.read())
+
+# the signatures use a format internally similar to 
+# protobuf's encoding, but without wire types
+class VariableReader(FromFileMixin):
+  """Protobuf-like encoding reader"""
+
+  def __init__(self, buf):
+      self.buf = buf
+      self.pos = 0
+      self.size = len(buf)
+ 
+  def read_int(self):
+    """Read a variable length integer"""
+    # _DecodeVarint will take care of out of range errors
+    (val, nextpos) = _di(self.buf, self.pos)
+    self.pos = nextpos
+    return val
+
+  def read_bytes_raw(self, size):      
+    """Read size bytes"""
+    b = self.buf[self.pos:self.pos+size]
+    self.pos += size
+    return b
+
+  def read_bytes(self):
+    """Read a bytes object""" 
+    size = self.read_int()
+    return self.read_bytes_raw(size)
+
+  def is_end(self):
+    return (self.size == self.pos)
+
+   
+class TaggedReader(VariableReader):
+  """Tagged reader, needed for implementing a WideVine signature reader"""
+
+  def read_tag(self):
+    """Read a tagged buffer"""
+    return (self.read_int(), self.read_bytes())
+
+  def read_all_tags(self, max_tag=3):
+      tags = {}
+      while (not self.is_end()):
+        (tag, bytes) = self.read_tag()
+        if (tag > max_tag):
+           raise IndexError("tag out of bound: got {}, max {}".format(tag, max_tag))
+
+        tags[tag] = bytes
+      return tags
+
+class WideVineSignatureReader(FromFileMixin):
+  """Parses a widevine .sig signature file."""
+
+  SIGNER_TAG = 1
+  SIGNATURE_TAG = 2
+  ISMAINEXE_TAG = 3
+
+  def __init__(self, buf):
+      reader = TaggedReader(buf)
+      self.version = reader.read_int()
+      if (self.version != 0):
+         raise Exception("Unsupported signature format version {}".format(self.version))
+      self.tags = reader.read_all_tags()
+
+      self.signer = self.tags[self.SIGNER_TAG]
+      self.signature = self.tags[self.SIGNATURE_TAG]
+
+      extra = self.tags[self.ISMAINEXE_TAG]
+      if (len(extra) != 1 or (extra[0] > 1)):
+         raise Exception("Unexpected 'ismainexe' field value (not '\\x00' or '\\x01'), please check: {0}".format(extra))
+      
+      self.mainexe = bool(extra[0])
+
+  @classmethod
+  def get_tags(cls, filename):
+    """Return a dictionary of each tag in the signature file"""
+    return cls.from_file(filename).tags
--- a/pywidevine/L1/decrypt/init.py
+++ b/pywidevine/L1/decrypt/init.py
--- a/pywidevine/L1/decrypt/pycache/init.cpython-37.pyc
+++ b/pywidevine/L1/decrypt/pycache/init.cpython-37.pyc
--- a/pywidevine/L1/decrypt/pycache/wvdecryptcustom.cpython-37.pyc
+++ b/pywidevine/L1/decrypt/pycache/wvdecryptcustom.cpython-37.pyc
--- a/pywidevine/L1/decrypt/wvdecryptcustom.py
+++ b/pywidevine/L1/decrypt/wvdecryptcustom.py
@ -0,0 +1,59 @@
+# uncompyle6 version 3.7.3
+# Python bytecode 3.6 (3379)
+# Decompiled from: Python 3.7.8 (tags/v3.7.8:4b47a5b6ba, Jun 28 2020, 08:53:46) [MSC v.1916 64 bit (AMD64)]
+# Embedded file name: pywidevine\decrypt\wvdecryptcustom.py
+import logging, subprocess, re, base64
+from pywidevine.L1.cdm import cdm, deviceconfig
+
+class WvDecrypt(object):
+    WV_SYSTEM_ID = [
+     237, 239, 139, 169, 121, 214, 74, 206, 163, 200, 39, 220, 213, 29, 33, 237]
+
+    def __init__(self, init_data_b64, cert_data_b64, device):
+        self.init_data_b64 = init_data_b64
+        self.cert_data_b64 = cert_data_b64
+        self.device = device
+        self.cdm = cdm.Cdm()
+
+        def check_pssh(pssh_b64):
+            pssh = base64.b64decode(pssh_b64)
+            if not pssh[12:28] == bytes(self.WV_SYSTEM_ID):
+                new_pssh = bytearray([0, 0, 0])
+                new_pssh.append(32 + len(pssh))
+                new_pssh[4:] = bytearray(b'pssh')
+                new_pssh[8:] = [0, 0, 0, 0]
+                new_pssh[13:] = self.WV_SYSTEM_ID
+                new_pssh[29:] = [0, 0, 0, 0]
+                new_pssh[31] = len(pssh)
+                new_pssh[32:] = pssh
+                return base64.b64encode(new_pssh)
+            else:
+                return pssh_b64
+
+        self.session = self.cdm.open_session(check_pssh(self.init_data_b64), deviceconfig.DeviceConfig(self.device))
+        if self.cert_data_b64:
+            self.cdm.set_service_certificate(self.session, self.cert_data_b64)
+
+    def log_message(self, msg):
+        return '{}'.format(msg)
+
+    def start_process(self):
+        keyswvdecrypt = []
+        try:
+            for key in self.cdm.get_keys(self.session):
+                if key.type == 'CONTENT':
+                    keyswvdecrypt.append(self.log_message('{}:{}'.format(key.kid.hex(), key.key.hex())))
+
+        except Exception:
+            return (
+             False, keyswvdecrypt)
+        else:
+            return (
+             True, keyswvdecrypt)
+
+    def get_challenge(self):
+        return self.cdm.get_license_request(self.session)
+
+    def update_license(self, license_b64):
+        self.cdm.provide_license(self.session, license_b64)
+        return True
--- a/pywidevine/L1/getPSSH.py
+++ b/pywidevine/L1/getPSSH.py
@ -0,0 +1,14 @@
+import requests, xmltodict, json
+
+def get_pssh(mpd_url):
+    r = requests.get(url=mpd_url)
+    r.raise_for_status()
+    xml = xmltodict.parse(r.text)
+    mpd = json.loads(json.dumps(xml))
+    tracks = mpd['MPD']['Period']['AdaptationSet']
+    for video_tracks in tracks:
+        if video_tracks['@mimeType'] == 'video/mp4':
+            for t in video_tracks["ContentProtection"]:
+                if t['@schemeIdUri'].lower() == "urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed":
+                    pssh = t["cenc:pssh"]
+    return pssh
--- a/pywidevine/L3/init.py
+++ b/pywidevine/L3/init.py
--- a/pywidevine/L3/pycache/init.cpython-37.pyc
+++ b/pywidevine/L3/pycache/init.cpython-37.pyc
--- a/pywidevine/L3/pycache/init.cpython-39.pyc
+++ b/pywidevine/L3/pycache/init.cpython-39.pyc
--- a/pywidevine/L3/pycache/getPSSH.cpython-37.pyc
+++ b/pywidevine/L3/pycache/getPSSH.cpython-37.pyc
--- a/pywidevine/L3/cdm/init.py
+++ b/pywidevine/L3/cdm/init.py
--- a/pywidevine/L3/cdm/pycache/init.cpython-37.pyc
+++ b/pywidevine/L3/cdm/pycache/init.cpython-37.pyc
--- a/pywidevine/L3/cdm/pycache/init.cpython-39.pyc
+++ b/pywidevine/L3/cdm/pycache/init.cpython-39.pyc
--- a/pywidevine/L3/cdm/pycache/cdm.cpython-37.pyc
+++ b/pywidevine/L3/cdm/pycache/cdm.cpython-37.pyc
--- a/pywidevine/L3/cdm/pycache/cdm.cpython-39.pyc
+++ b/pywidevine/L3/cdm/pycache/cdm.cpython-39.pyc
--- a/pywidevine/L3/cdm/pycache/deviceconfig.cpython-37.pyc
+++ b/pywidevine/L3/cdm/pycache/deviceconfig.cpython-37.pyc
--- a/pywidevine/L3/cdm/pycache/deviceconfig.cpython-39.pyc
+++ b/pywidevine/L3/cdm/pycache/deviceconfig.cpython-39.pyc
--- a/pywidevine/L3/cdm/pycache/key.cpython-37.pyc
+++ b/pywidevine/L3/cdm/pycache/key.cpython-37.pyc
--- a/pywidevine/L3/cdm/pycache/key.cpython-39.pyc
+++ b/pywidevine/L3/cdm/pycache/key.cpython-39.pyc
--- a/pywidevine/L3/cdm/pycache/session.cpython-37.pyc
+++ b/pywidevine/L3/cdm/pycache/session.cpython-37.pyc
--- a/pywidevine/L3/cdm/pycache/session.cpython-39.pyc
+++ b/pywidevine/L3/cdm/pycache/session.cpython-39.pyc
--- a/pywidevine/L3/cdm/cdm.py
+++ b/pywidevine/L3/cdm/cdm.py
@ -0,0 +1,362 @@
+import base64
+
+import os
+import time
+import binascii
+
+from google.protobuf.message import DecodeError
+from google.protobuf import text_format
+
+from pywidevine.L3.cdm.formats import wv_proto2_pb2 as wv_proto2
+from pywidevine.L3.cdm.session import Session
+from pywidevine.L3.cdm.key import Key
+from Cryptodome.Random import get_random_bytes
+from Cryptodome.Random import random
+from Cryptodome.Cipher import PKCS1_OAEP, AES
+from Cryptodome.Hash import CMAC, SHA256, HMAC, SHA1
+from Cryptodome.PublicKey import RSA
+from Cryptodome.Signature import pss
+from Cryptodome.Util import Padding
+import logging
+
+class Cdm:
+    def __init__(self):
+        self.logger = logging.getLogger(__name__)
+        self.sessions = {}
+
+    def open_session(self, init_data_b64, device, raw_init_data = None, offline=False):
+        self.logger.debug("open_session(init_data_b64={}, device={}".format(init_data_b64, device))
+        self.logger.info("opening new cdm session")
+        if device.session_id_type == 'android':
+            # format: 16 random hexdigits, 2 digit counter, 14 0s
+            rand_ascii = ''.join(random.choice('ABCDEF0123456789') for _ in range(16))
+            counter = '01' # this resets regularly so its fine to use 01
+            rest = '00000000000000'
+            session_id = rand_ascii + counter + rest
+            session_id = session_id.encode('ascii')
+        elif device.session_id_type == 'chrome':
+            rand_bytes = get_random_bytes(16)
+            session_id = rand_bytes
+        else:
+            # other formats NYI
+            self.logger.error("device type is unusable")
+            return 1
+        if raw_init_data and isinstance(raw_init_data, (bytes, bytearray)):
+            # used for NF key exchange, where they don't provide a valid PSSH
+            init_data = raw_init_data
+            self.raw_pssh = True
+        else:
+            init_data = self._parse_init_data(init_data_b64)
+            self.raw_pssh = False
+
+        if init_data:
+            new_session = Session(session_id, init_data, device, offline)
+        else:
+            self.logger.error("unable to parse init data")
+            return 1
+        self.sessions[session_id] = new_session
+        self.logger.info("session opened and init data parsed successfully")
+        return session_id
+
+    def _parse_init_data(self, init_data_b64):
+        parsed_init_data = wv_proto2.WidevineCencHeader()
+        try:
+            self.logger.debug("trying to parse init_data directly")
+            parsed_init_data.ParseFromString(base64.b64decode(init_data_b64)[32:])
+        except DecodeError:
+            self.logger.debug("unable to parse as-is, trying with removed pssh box header")
+            try:
+                id_bytes = parsed_init_data.ParseFromString(base64.b64decode(init_data_b64)[32:])
+            except DecodeError:
+                self.logger.error("unable to parse, unsupported init data format")
+                return None
+        self.logger.debug("init_data:")
+        for line in text_format.MessageToString(parsed_init_data).splitlines():
+            self.logger.debug(line)
+        return parsed_init_data
+
+    def close_session(self, session_id):
+        self.logger.debug("close_session(session_id={})".format(session_id))
+        self.logger.info("closing cdm session")
+        if session_id in self.sessions:
+            self.sessions.pop(session_id)
+            self.logger.info("cdm session closed")
+            return 0
+        else:
+            self.logger.info("session {} not found".format(session_id))
+            return 1
+
+    def set_service_certificate(self, session_id, cert_b64):
+        self.logger.debug("set_service_certificate(session_id={}, cert={})".format(session_id, cert_b64))
+        self.logger.info("setting service certificate")
+
+        if session_id not in self.sessions:
+            self.logger.error("session id doesn't exist")
+            return 1
+
+        session = self.sessions[session_id]
+
+        message = wv_proto2.SignedMessage()
+
+        try:
+            message.ParseFromString(base64.b64decode(cert_b64))
+        except DecodeError:
+            self.logger.error("failed to parse cert as SignedMessage")
+
+        service_certificate = wv_proto2.SignedDeviceCertificate()
+
+        if message.Type:
+            self.logger.debug("service cert provided as signedmessage")
+            try:
+                service_certificate.ParseFromString(message.Msg)
+            except DecodeError:
+                self.logger.error("failed to parse service certificate")
+                return 1
+        else:
+            self.logger.debug("service cert provided as signeddevicecertificate")
+            try:
+                service_certificate.ParseFromString(base64.b64decode(cert_b64))
+            except DecodeError:
+                self.logger.error("failed to parse service certificate")
+                return 1
+
+        self.logger.debug("service certificate:")
+        for line in text_format.MessageToString(service_certificate).splitlines():
+            self.logger.debug(line)
+
+        session.service_certificate = service_certificate
+        session.privacy_mode = True
+
+        return 0
+
+    def get_license_request(self, session_id):
+        self.logger.debug("get_license_request(session_id={})".format(session_id))
+        self.logger.info("getting license request")
+
+        if session_id not in self.sessions:
+            self.logger.error("session ID does not exist")
+            return 1
+
+        session = self.sessions[session_id]
+
+        # raw pssh will be treated as bytes and not parsed
+        if self.raw_pssh:
+            license_request = wv_proto2.SignedLicenseRequestRaw()
+        else:
+            license_request = wv_proto2.SignedLicenseRequest()
+        client_id = wv_proto2.ClientIdentification()
+
+        if not os.path.exists(session.device_config.device_client_id_blob_filename):
+            self.logger.error("no client ID blob available for this device")
+            return 1
+
+        with open(session.device_config.device_client_id_blob_filename, "rb") as f:
+            try:
+                cid_bytes = client_id.ParseFromString(f.read())
+            except DecodeError:
+                self.logger.error("client id failed to parse as protobuf")
+                return 1
+
+        self.logger.debug("building license request")
+        if not self.raw_pssh:
+            license_request.Type = wv_proto2.SignedLicenseRequest.MessageType.Value('LICENSE_REQUEST')
+            license_request.Msg.ContentId.CencId.Pssh.CopyFrom(session.init_data)
+        else:
+            license_request.Type = wv_proto2.SignedLicenseRequestRaw.MessageType.Value('LICENSE_REQUEST')
+            license_request.Msg.ContentId.CencId.Pssh = session.init_data # bytes
+
+        if session.offline:
+           license_type = wv_proto2.LicenseType.Value('OFFLINE')
+        else:
+           license_type = wv_proto2.LicenseType.Value('DEFAULT')
+        license_request.Msg.ContentId.CencId.LicenseType = license_type
+        license_request.Msg.ContentId.CencId.RequestId = session_id
+        license_request.Msg.Type = wv_proto2.LicenseRequest.RequestType.Value('NEW')
+        license_request.Msg.RequestTime = int(time.time())
+        license_request.Msg.ProtocolVersion = wv_proto2.ProtocolVersion.Value('CURRENT')
+        if session.device_config.send_key_control_nonce:
+            license_request.Msg.KeyControlNonce = random.randrange(1, 2**31)
+
+        if session.privacy_mode:
+            if session.device_config.vmp:
+                self.logger.debug("vmp required, adding to client_id")
+                self.logger.debug("reading vmp hashes")
+                vmp_hashes = wv_proto2.FileHashes()
+                with open(session.device_config.device_vmp_blob_filename, "rb") as f:
+                    try:
+                        vmp_bytes = vmp_hashes.ParseFromString(f.read())
+                    except DecodeError:
+                        self.logger.error("vmp hashes failed to parse as protobuf")
+                        return 1
+                client_id._FileHashes.CopyFrom(vmp_hashes)
+            self.logger.debug("privacy mode & service certificate loaded, encrypting client id")
+            self.logger.debug("unencrypted client id:")
+            for line in text_format.MessageToString(client_id).splitlines():
+                self.logger.debug(line)
+            cid_aes_key = get_random_bytes(16)
+            cid_iv = get_random_bytes(16)
+
+            cid_cipher = AES.new(cid_aes_key, AES.MODE_CBC, cid_iv)
+
+            encrypted_client_id = cid_cipher.encrypt(Padding.pad(client_id.SerializeToString(), 16))
+
+            service_public_key = RSA.importKey(session.service_certificate._DeviceCertificate.PublicKey)
+
+            service_cipher = PKCS1_OAEP.new(service_public_key)
+
+            encrypted_cid_key = service_cipher.encrypt(cid_aes_key)
+
+            encrypted_client_id_proto = wv_proto2.EncryptedClientIdentification()
+
+            encrypted_client_id_proto.ServiceId = session.service_certificate._DeviceCertificate.ServiceId
+            encrypted_client_id_proto.ServiceCertificateSerialNumber = session.service_certificate._DeviceCertificate.SerialNumber
+            encrypted_client_id_proto.EncryptedClientId = encrypted_client_id
+            encrypted_client_id_proto.EncryptedClientIdIv = cid_iv
+            encrypted_client_id_proto.EncryptedPrivacyKey = encrypted_cid_key
+
+            license_request.Msg.EncryptedClientId.CopyFrom(encrypted_client_id_proto)
+        else:
+            license_request.Msg.ClientId.CopyFrom(client_id)
+
+        if session.device_config.private_key_available:
+             key = RSA.importKey(open(session.device_config.device_private_key_filename).read())
+             session.device_key = key
+        else:
+             self.logger.error("need device private key, other methods unimplemented")
+             return 1
+
+        self.logger.debug("signing license request")
+
+        hash = SHA1.new(license_request.Msg.SerializeToString())
+        signature = pss.new(key).sign(hash)
+
+        license_request.Signature = signature
+
+        session.license_request = license_request
+
+        self.logger.debug("license request:")
+        for line in text_format.MessageToString(session.license_request).splitlines():
+            self.logger.debug(line)
+        self.logger.info("license request created")
+        self.logger.debug("license request b64: {}".format(base64.b64encode(license_request.SerializeToString())))
+        return license_request.SerializeToString()
+
+    def provide_license(self, session_id, license_b64):
+        self.logger.debug("provide_license(session_id={}, license_b64={})".format(session_id, license_b64))
+        self.logger.info("decrypting provided license")
+
+        if session_id not in self.sessions:
+            self.logger.error("session does not exist")
+            return 1
+
+        session = self.sessions[session_id]
+
+        if not session.license_request:
+            self.logger.error("generate a license request first!")
+            return 1
+
+        license = wv_proto2.SignedLicense()
+        try:
+            license.ParseFromString(base64.b64decode(license_b64))
+        except DecodeError:
+            self.logger.error("unable to parse license - check protobufs")
+            return 1
+
+        session.license = license
+
+        self.logger.debug("license:")
+        for line in text_format.MessageToString(license).splitlines():
+            self.logger.debug(line)
+
+        self.logger.debug("deriving keys from session key")
+
+        oaep_cipher = PKCS1_OAEP.new(session.device_key)
+
+        session.session_key = oaep_cipher.decrypt(license.SessionKey)
+
+        lic_req_msg = session.license_request.Msg.SerializeToString()
+
+        enc_key_base = b"ENCRYPTION\000" + lic_req_msg + b"\0\0\0\x80"
+        auth_key_base = b"AUTHENTICATION\0" + lic_req_msg + b"\0\0\2\0"
+
+        enc_key = b"\x01" + enc_key_base
+        auth_key_1 = b"\x01" + auth_key_base
+        auth_key_2 = b"\x02" + auth_key_base
+        auth_key_3 = b"\x03" + auth_key_base
+        auth_key_4 = b"\x04" + auth_key_base
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(enc_key)
+
+        enc_cmac_key = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_1)
+        auth_cmac_key_1 = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_2)
+        auth_cmac_key_2 = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_3)
+        auth_cmac_key_3 = cmac_obj.digest()
+
+        cmac_obj = CMAC.new(session.session_key, ciphermod=AES)
+        cmac_obj.update(auth_key_4)
+        auth_cmac_key_4 = cmac_obj.digest()
+
+        auth_cmac_combined_1 = auth_cmac_key_1 + auth_cmac_key_2
+        auth_cmac_combined_2 = auth_cmac_key_3 + auth_cmac_key_4
+
+        session.derived_keys['enc'] = enc_cmac_key
+        session.derived_keys['auth_1'] = auth_cmac_combined_1
+        session.derived_keys['auth_2'] = auth_cmac_combined_2
+
+        self.logger.debug('verifying license signature')
+
+        lic_hmac = HMAC.new(session.derived_keys['auth_1'], digestmod=SHA256)
+        lic_hmac.update(license.Msg.SerializeToString())
+
+        self.logger.debug("calculated sig: {} actual sig: {}".format(lic_hmac.hexdigest(), binascii.hexlify(license.Signature)))
+
+        if lic_hmac.digest() != license.Signature:
+            self.logger.info("license signature doesn't match - writing bin so they can be debugged")
+            with open("original_lic.bin", "wb") as f:
+                f.write(base64.b64decode(license_b64))
+            with open("parsed_lic.bin", "wb") as f:
+                f.write(license.SerializeToString())
+            self.logger.info("continuing anyway")
+
+        self.logger.debug("key count: {}".format(len(license.Msg.Key)))
+        for key in license.Msg.Key:
+            if key.Id:
+                key_id = key.Id
+            else:
+                key_id = wv_proto2.License.KeyContainer.KeyType.Name(key.Type).encode('utf-8')
+            encrypted_key = key.Key
+            iv = key.Iv
+            type = wv_proto2.License.KeyContainer.KeyType.Name(key.Type)
+
+            cipher = AES.new(session.derived_keys['enc'], AES.MODE_CBC, iv=iv)
+            decrypted_key = cipher.decrypt(encrypted_key)
+            if type == "OPERATOR_SESSION":
+                permissions = []
+                perms = key._OperatorSessionKeyPermissions
+                for (descriptor, value) in perms.ListFields():
+                    if value == 1:
+                        permissions.append(descriptor.name)
+                print(permissions)
+            else:
+                permissions = []
+            session.keys.append(Key(key_id, type, Padding.unpad(decrypted_key, 16), permissions))
+
+        self.logger.info("decrypted all keys")
+        return 0
+
+    def get_keys(self, session_id):
+        if session_id in self.sessions:
+            return self.sessions[session_id].keys
+        else:
+            self.logger.error("session not found")
+            return 1
--- a/pywidevine/L3/cdm/deviceconfig.py
+++ b/pywidevine/L3/cdm/deviceconfig.py
@ -0,0 +1,53 @@
+import os
+
+device_android_generic = {
+    'name': 'android_generic',
+    'description': 'android studio cdm',
+    'security_level': 1,
+    'session_id_type': 'android',
+    'private_key_available': True,
+    'vmp': False,
+    'send_key_control_nonce': True
+}
+
+devices_available = [device_android_generic]
+
+FILES_FOLDER = 'devices'
+
+class DeviceConfig:
+    def __init__(self, device):
+        self.device_name = device['name']
+        self.description = device['description']
+        self.security_level = device['security_level']
+        self.session_id_type = device['session_id_type']
+        self.private_key_available = device['private_key_available']
+        self.vmp = device['vmp']
+        self.send_key_control_nonce = device['send_key_control_nonce']
+
+        if 'keybox_filename' in device:
+            self.keybox_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['keybox_filename'])
+        else:
+            self.keybox_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'keybox')
+
+        if 'device_cert_filename' in device:
+            self.device_cert_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_cert_filename'])
+        else:
+            self.device_cert_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_cert')
+
+        if 'device_private_key_filename' in device:
+            self.device_private_key_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_private_key_filename'])
+        else:
+            self.device_private_key_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_private_key')
+
+        if 'device_client_id_blob_filename' in device:
+            self.device_client_id_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_client_id_blob_filename'])
+        else:
+            self.device_client_id_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_client_id_blob')
+
+        if 'device_vmp_blob_filename' in device:
+            self.device_vmp_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], device['device_vmp_blob_filename'])
+        else:
+            self.device_vmp_blob_filename = os.path.join(os.path.dirname(__file__), FILES_FOLDER, device['name'], 'device_vmp_blob')
+
+    def __repr__(self):
+        return "DeviceConfig(name={}, description={}, security_level={}, session_id_type={}, private_key_available={}, vmp={})".format(self.device_name, self.description, self.security_level, self.session_id_type, self.private_key_available, self.vmp)
--- a/pywidevine/L3/cdm/formats/init.py
+++ b/pywidevine/L3/cdm/formats/init.py
--- a/pywidevine/L3/cdm/formats/pycache/init.cpython-37.pyc
+++ b/pywidevine/L3/cdm/formats/pycache/init.cpython-37.pyc
--- a/pywidevine/L3/cdm/formats/pycache/init.cpython-39.pyc
+++ b/pywidevine/L3/cdm/formats/pycache/init.cpython-39.pyc
--- a/pywidevine/L3/cdm/formats/pycache/wv_proto2_pb2.cpython-37.pyc
+++ b/pywidevine/L3/cdm/formats/pycache/wv_proto2_pb2.cpython-37.pyc
--- a/pywidevine/L3/cdm/formats/pycache/wv_proto2_pb2.cpython-39.pyc
+++ b/pywidevine/L3/cdm/formats/pycache/wv_proto2_pb2.cpython-39.pyc
--- a/pywidevine/L3/cdm/formats/wv_proto2.proto
+++ b/pywidevine/L3/cdm/formats/wv_proto2.proto
@ -0,0 +1,466 @@
+syntax = "proto2";
+
+// from x86 (partial), most of it from the ARM version:
+message ClientIdentification {
+    enum TokenType {
+        KEYBOX = 0;
+        DEVICE_CERTIFICATE = 1;
+        REMOTE_ATTESTATION_CERTIFICATE = 2;
+    }
+    message NameValue {
+        required string Name = 1;
+        required string Value = 2;
+    }
+    message ClientCapabilities {
+        enum HdcpVersion {
+            HDCP_NONE = 0;
+            HDCP_V1 = 1;
+            HDCP_V2 = 2;
+            HDCP_V2_1 = 3;
+            HDCP_V2_2 = 4;
+        }
+        optional uint32 ClientToken = 1;
+        optional uint32 SessionToken = 2;
+        optional uint32 VideoResolutionConstraints = 3;
+        optional HdcpVersion MaxHdcpVersion = 4;
+        optional uint32 OemCryptoApiVersion = 5;
+    }
+    required TokenType Type = 1;
+    //optional bytes Token = 2; // by default the client treats this as blob, but it's usually a DeviceCertificate, so for usefulness sake, I'm replacing it with this one:
+    optional SignedDeviceCertificate Token = 2; // use this when parsing, "bytes" when building a client id blob
+    repeated NameValue ClientInfo = 3;
+    optional bytes ProviderClientToken = 4;
+    optional uint32 LicenseCounter = 5;
+    optional ClientCapabilities _ClientCapabilities = 6; // how should we deal with duped names? will have to look at proto docs later
+    optional FileHashes _FileHashes = 7; // vmp blob goes here
+}
+
+message DeviceCertificate {
+    enum CertificateType {
+        ROOT = 0;
+        INTERMEDIATE = 1;
+        USER_DEVICE = 2;
+        SERVICE = 3;
+    }
+    required CertificateType Type = 1; // the compiled code reused this as ProvisionedDeviceInfo.WvSecurityLevel, however that is incorrect (compiler aliased it as they're both identical as a structure)
+    optional bytes SerialNumber = 2;
+    optional uint32 CreationTimeSeconds = 3;
+    optional bytes PublicKey = 4;
+    optional uint32 SystemId = 5;
+    optional uint32 TestDeviceDeprecated = 6; // is it bool or int?
+    optional bytes ServiceId = 7; // service URL for service certificates
+}
+
+// missing some references,
+message DeviceCertificateStatus {
+    enum CertificateStatus {
+        VALID = 0;
+        REVOKED = 1;
+    }
+    optional bytes SerialNumber = 1;
+    optional CertificateStatus Status = 2;
+    optional ProvisionedDeviceInfo DeviceInfo = 4; // where is 3? is it deprecated?
+}
+
+message DeviceCertificateStatusList {
+    optional uint32 CreationTimeSeconds = 1;
+    repeated DeviceCertificateStatus CertificateStatus = 2;
+}
+
+message EncryptedClientIdentification {
+    required string ServiceId = 1;
+    optional bytes ServiceCertificateSerialNumber = 2;
+    required bytes EncryptedClientId = 3;
+    required bytes EncryptedClientIdIv = 4;
+    required bytes EncryptedPrivacyKey = 5;
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+enum LicenseType {
+    ZERO = 0;
+    DEFAULT = 1; // 1 is STREAMING/temporary license; on recent versions may go up to 3 (latest x86); it might be persist/don't persist type, unconfirmed
+    OFFLINE = 2;
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+// this is just a guess because these globals got lost, but really, do we need more?
+enum ProtocolVersion {
+    CURRENT = 21; // don't have symbols for this
+}
+
+
+message LicenseIdentification {
+    optional bytes RequestId = 1;
+    optional bytes SessionId = 2;
+    optional bytes PurchaseId = 3;
+    optional LicenseType Type = 4;
+    optional uint32 Version = 5;
+    optional bytes ProviderSessionToken = 6;
+}
+
+
+message License {
+    message Policy {
+        optional bool CanPlay = 1; // changed from uint32 to bool
+        optional bool CanPersist = 2;
+        optional bool CanRenew = 3;
+        optional uint32 RentalDurationSeconds = 4;
+        optional uint32 PlaybackDurationSeconds = 5;
+        optional uint32 LicenseDurationSeconds = 6;
+        optional uint32 RenewalRecoveryDurationSeconds = 7;
+        optional string RenewalServerUrl = 8;
+        optional uint32 RenewalDelaySeconds = 9;
+        optional uint32 RenewalRetryIntervalSeconds = 10;
+        optional bool RenewWithUsage = 11; // was uint32
+    }
+    message KeyContainer {
+        enum KeyType {
+            SIGNING = 1;
+            CONTENT = 2;
+            KEY_CONTROL = 3;
+            OPERATOR_SESSION = 4;
+        }
+        enum SecurityLevel {
+            SW_SECURE_CRYPTO = 1;
+            SW_SECURE_DECODE = 2;
+            HW_SECURE_CRYPTO = 3;
+            HW_SECURE_DECODE = 4;
+            HW_SECURE_ALL = 5;
+        }
+        message OutputProtection {
+            enum CGMS {
+                COPY_FREE = 0;
+                COPY_ONCE = 2;
+                COPY_NEVER = 3;
+                CGMS_NONE = 0x2A; // PC default!
+            }
+            optional ClientIdentification.ClientCapabilities.HdcpVersion Hdcp = 1; // it's most likely a copy of Hdcp version available here, but compiler optimized it away
+            optional CGMS CgmsFlags = 2;
+        }
+        message KeyControl {
+            required bytes KeyControlBlock = 1; // what is this?
+            required bytes Iv = 2;
+        }
+        message OperatorSessionKeyPermissions {
+            optional uint32 AllowEncrypt = 1;
+            optional uint32 AllowDecrypt = 2;
+            optional uint32 AllowSign = 3;
+            optional uint32 AllowSignatureVerify = 4;
+        }
+        message VideoResolutionConstraint {
+            optional uint32 MinResolutionPixels = 1;
+            optional uint32 MaxResolutionPixels = 2;
+            optional OutputProtection RequiredProtection = 3;
+        }
+        optional bytes Id = 1;
+        optional bytes Iv = 2;
+        optional bytes Key = 3;
+        optional KeyType Type = 4;
+        optional SecurityLevel Level = 5;
+        optional OutputProtection RequiredProtection = 6;
+        optional OutputProtection RequestedProtection = 7;
+        optional KeyControl _KeyControl = 8; // duped names, etc
+        optional OperatorSessionKeyPermissions _OperatorSessionKeyPermissions = 9; // duped names, etc
+        repeated VideoResolutionConstraint VideoResolutionConstraints = 10;
+    }
+    optional LicenseIdentification Id = 1;
+    optional Policy _Policy = 2; // duped names, etc
+    repeated KeyContainer Key = 3;
+    optional uint32 LicenseStartTime = 4;
+    optional uint32 RemoteAttestationVerified = 5; // bool?
+    optional bytes ProviderClientToken = 6;
+    // there might be more, check with newer versions (I see field 7-8 in a lic)
+    // this appeared in latest x86:
+    optional uint32 ProtectionScheme = 7; // type unconfirmed fully, but it's likely as WidevineCencHeader describesit (fourcc)
+}
+
+message LicenseError {
+    enum Error {
+        INVALID_DEVICE_CERTIFICATE = 1;
+        REVOKED_DEVICE_CERTIFICATE = 2;
+        SERVICE_UNAVAILABLE = 3;
+    }
+    //LicenseRequest.RequestType ErrorCode; // clang mismatch
+    optional Error ErrorCode = 1;
+}
+
+message LicenseRequest {
+    message ContentIdentification {
+        message CENC {
+            //optional bytes Pssh = 1; // the client's definition is opaque, it doesn't care about the contents, but the PSSH has a clear definition that is understood and requested by the server, thus I'll replace it with:
+            optional WidevineCencHeader Pssh = 1;
+            optional LicenseType LicenseType = 2; // unfortunately the LicenseType symbols are not present, acceptable value seems to only be 1 (is this persist/don't persist? look into it!)
+            optional bytes RequestId = 3;
+        }
+        message WebM {
+            optional bytes Header = 1; // identical to CENC, aside from PSSH and the parent field number used
+            optional LicenseType LicenseType = 2;
+            optional bytes RequestId = 3;
+        }
+        message ExistingLicense {
+            optional LicenseIdentification LicenseId = 1;
+            optional uint32 SecondsSinceStarted = 2;
+            optional uint32 SecondsSinceLastPlayed = 3;
+            optional bytes SessionUsageTableEntry = 4; // interesting! try to figure out the connection between the usage table blob and KCB!
+        }
+        optional CENC CencId = 1;
+        optional WebM WebmId = 2;
+        optional ExistingLicense License = 3;
+    }
+    enum RequestType {
+        NEW = 1;
+        RENEWAL = 2;
+        RELEASE = 3;
+    }
+    optional ClientIdentification ClientId = 1;
+    optional ContentIdentification ContentId = 2;
+    optional RequestType Type = 3;
+    optional uint32 RequestTime = 4;
+    optional bytes KeyControlNonceDeprecated = 5;
+    optional ProtocolVersion ProtocolVersion = 6; // lacking symbols for this
+    optional uint32 KeyControlNonce = 7;
+    optional EncryptedClientIdentification EncryptedClientId = 8;
+}
+
+// raw pssh hack
+message LicenseRequestRaw {
+    message ContentIdentification {
+        message CENC {
+            optional bytes Pssh = 1; // the client's definition is opaque, it doesn't care about the contents, but the PSSH has a clear definition that is understood and requested by the server, thus I'll replace it with:
+            //optional WidevineCencHeader Pssh = 1;
+            optional LicenseType LicenseType = 2; // unfortunately the LicenseType symbols are not present, acceptable value seems to only be 1 (is this persist/don't persist? look into it!)
+            optional bytes RequestId = 3;
+        }
+        message WebM {
+            optional bytes Header = 1; // identical to CENC, aside from PSSH and the parent field number used
+            optional LicenseType LicenseType = 2;
+            optional bytes RequestId = 3;
+        }
+        message ExistingLicense {
+            optional LicenseIdentification LicenseId = 1;
+            optional uint32 SecondsSinceStarted = 2;
+            optional uint32 SecondsSinceLastPlayed = 3;
+            optional bytes SessionUsageTableEntry = 4; // interesting! try to figure out the connection between the usage table blob and KCB!
+        }
+        optional CENC CencId = 1;
+        optional WebM WebmId = 2;
+        optional ExistingLicense License = 3;
+    }
+    enum RequestType {
+        NEW = 1;
+        RENEWAL = 2;
+        RELEASE = 3;
+    }
+    optional ClientIdentification ClientId = 1;
+    optional ContentIdentification ContentId = 2;
+    optional RequestType Type = 3;
+    optional uint32 RequestTime = 4;
+    optional bytes KeyControlNonceDeprecated = 5;
+    optional ProtocolVersion ProtocolVersion = 6; // lacking symbols for this
+    optional uint32 KeyControlNonce = 7;
+    optional EncryptedClientIdentification EncryptedClientId = 8;
+}
+
+
+message ProvisionedDeviceInfo {
+    enum WvSecurityLevel {
+        LEVEL_UNSPECIFIED = 0;
+        LEVEL_1 = 1;
+        LEVEL_2 = 2;
+        LEVEL_3 = 3;
+    }
+    optional uint32 SystemId = 1;
+    optional string Soc = 2;
+    optional string Manufacturer = 3;
+    optional string Model = 4;
+    optional string DeviceType = 5;
+    optional uint32 ModelYear = 6;
+    optional WvSecurityLevel SecurityLevel = 7;
+    optional uint32 TestDevice = 8; // bool?
+}
+
+
+// todo: fill
+message ProvisioningOptions {
+}
+
+// todo: fill
+message ProvisioningRequest {
+}
+
+// todo: fill
+message ProvisioningResponse {
+}
+
+message RemoteAttestation {
+    optional EncryptedClientIdentification Certificate = 1;
+    optional string Salt = 2;
+    optional string Signature = 3;
+}
+
+// todo: fill
+message SessionInit {
+}
+
+// todo: fill
+message SessionState {
+}
+
+// todo: fill
+message SignedCertificateStatusList {
+}
+
+message SignedDeviceCertificate {
+
+    //optional bytes DeviceCertificate = 1; // again, they use a buffer where it's supposed to be a message, so we'll replace it with what it really is:
+    optional DeviceCertificate _DeviceCertificate = 1; // how should we deal with duped names? will have to look at proto docs later
+    optional bytes Signature = 2;
+    optional SignedDeviceCertificate Signer = 3;
+}
+
+
+// todo: fill
+message SignedProvisioningMessage {
+}
+
+// the root of all messages, from either server or client
+message SignedMessage {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional bytes Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+
+
+// This message is copied from google's docs, not reversed:
+message WidevineCencHeader {
+    enum Algorithm {
+        UNENCRYPTED = 0;
+        AESCTR = 1;
+    };
+    optional Algorithm algorithm = 1;
+    repeated bytes key_id = 2;
+
+    // Content provider name.
+    optional string provider = 3;
+
+    // A content identifier, specified by content provider.
+    optional bytes content_id = 4;
+
+    // Track type. Acceptable values are SD, HD and AUDIO. Used to
+    // differentiate content keys used by an asset.
+    optional string track_type_deprecated = 5;
+
+    // The name of a registered policy to be used for this asset.
+    optional string policy = 6;
+
+    // Crypto period index, for media using key rotation.
+    optional uint32 crypto_period_index = 7;
+
+    // Optional protected context for group content. The grouped_license is a
+    // serialized SignedMessage.
+    optional bytes grouped_license = 8;
+
+    // Protection scheme identifying the encryption algorithm.
+    // Represented as one of the following 4CC values:
+    // 'cenc' (AESCTR), 'cbc1' (AESCBC),
+    // 'cens' (AESCTR subsample), 'cbcs' (AESCBC subsample).
+    optional uint32 protection_scheme = 9;
+
+    // Optional. For media using key rotation, this represents the duration
+    // of each crypto period in seconds.
+    optional uint32 crypto_period_seconds = 10;
+}
+
+
+// remove these when using it outside of protoc:
+
+// from here on, it's just for testing, these messages don't exist in the binaries, I'm adding them to avoid detecting type programmatically
+message SignedLicenseRequest {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional LicenseRequest Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+// hack
+message SignedLicenseRequestRaw {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional LicenseRequestRaw Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+
+message SignedLicense {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional License Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+message SignedServiceCertificate {
+    enum MessageType {
+        LICENSE_REQUEST = 1;
+        LICENSE = 2;
+        ERROR_RESPONSE = 3;
+        SERVICE_CERTIFICATE_REQUEST = 4;
+        SERVICE_CERTIFICATE = 5;
+    }
+    optional MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+    optional SignedDeviceCertificate Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+    // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+    optional bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+    optional bytes SessionKey = 4; // often RSA wrapped for licenses
+    optional RemoteAttestation RemoteAttestation = 5;
+}
+
+//vmp support
+message FileHashes {
+   message Signature {
+     optional string filename = 1;
+     optional bool test_signing = 2; //0 - release, 1 - testing
+     optional bytes SHA512Hash = 3;
+     optional bool main_exe = 4; //0 for dlls, 1 for exe, this is field 3 in file
+     optional bytes signature = 5;
+   }
+   optional bytes signer = 1;
+   repeated Signature signatures = 2;
+}
--- a/pywidevine/L3/cdm/formats/wv_proto2_pb2.py
+++ b/pywidevine/L3/cdm/formats/wv_proto2_pb2.py
--- a/pywidevine/L3/cdm/formats/wv_proto3.proto
+++ b/pywidevine/L3/cdm/formats/wv_proto3.proto
@ -0,0 +1,389 @@
+// beware proto3 won't show missing fields it seems, need to change to "proto2" and add "optional" before every field, and remove all the dummy enum members I added:
+syntax = "proto3";
+
+// from x86 (partial), most of it from the ARM version:
+message ClientIdentification {
+  enum TokenType {
+    KEYBOX = 0;
+    DEVICE_CERTIFICATE = 1;
+    REMOTE_ATTESTATION_CERTIFICATE = 2;
+  }
+  message NameValue {
+    string Name = 1;
+    string Value = 2;
+  }
+  message ClientCapabilities {
+    enum HdcpVersion {
+      HDCP_NONE = 0;
+      HDCP_V1 = 1;
+      HDCP_V2 = 2;
+      HDCP_V2_1 = 3;
+      HDCP_V2_2 = 4;
+    }
+    uint32 ClientToken = 1;
+    uint32 SessionToken = 2;
+    uint32 VideoResolutionConstraints = 3;
+    HdcpVersion MaxHdcpVersion = 4;
+    uint32 OemCryptoApiVersion = 5;
+  }
+  TokenType Type = 1;
+  //bytes Token = 2; // by default the client treats this as blob, but it's usually a DeviceCertificate, so for usefulness sake, I'm replacing it with this one:
+  SignedDeviceCertificate Token = 2; 
+  repeated NameValue ClientInfo = 3;
+  bytes ProviderClientToken = 4;
+  uint32 LicenseCounter = 5;
+  ClientCapabilities _ClientCapabilities = 6; // how should we deal with duped names? will have to look at proto docs later
+}
+
+message DeviceCertificate {
+  enum CertificateType {
+    ROOT = 0;
+    INTERMEDIATE = 1;
+    USER_DEVICE = 2;
+    SERVICE = 3;
+  }
+  //ProvisionedDeviceInfo.WvSecurityLevel Type = 1; // is this how one is supposed to call it? (it's an enum) there might be a bug here, with CertificateType getting confused with WvSecurityLevel, for now renaming it (verify against other binaries)
+  CertificateType Type = 1;
+  bytes SerialNumber = 2; 
+  uint32 CreationTimeSeconds = 3;
+  bytes PublicKey = 4;
+  uint32 SystemId = 5;
+  uint32 TestDeviceDeprecated = 6; // is it bool or int?
+  bytes ServiceId = 7; // service URL for service certificates
+}
+
+// missing some references, 
+message DeviceCertificateStatus {
+  enum CertificateStatus {
+    VALID = 0;
+    REVOKED = 1;
+  }
+  bytes SerialNumber = 1;
+  CertificateStatus Status = 2; 
+  ProvisionedDeviceInfo DeviceInfo = 4; // where is 3? is it deprecated?
+}
+
+message DeviceCertificateStatusList {
+  uint32 CreationTimeSeconds = 1;
+  repeated DeviceCertificateStatus CertificateStatus = 2;
+}
+
+message EncryptedClientIdentification {
+  string ServiceId = 1;
+  bytes ServiceCertificateSerialNumber = 2;
+  bytes EncryptedClientId = 3;
+  bytes EncryptedClientIdIv = 4;
+  bytes EncryptedPrivacyKey = 5;
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+enum LicenseType {
+  ZERO = 0;
+  DEFAULT = 1; // do not know what this is either, but should be 1; on recent versions may go up to 3 (latest x86)
+}
+
+// todo: fill (for this top-level type, it might be impossible/difficult)
+// this is just a guess because these globals got lost, but really, do we need more? 
+enum ProtocolVersion {
+  DUMMY = 0;
+  CURRENT = 21; // don't have symbols for this
+}
+
+
+message LicenseIdentification {
+  bytes RequestId = 1;
+  bytes SessionId = 2;
+  bytes PurchaseId = 3;
+  LicenseType Type = 4;
+  uint32 Version = 5;
+  bytes ProviderSessionToken = 6;
+}
+
+
+message License {
+  message Policy {
+    uint32 CanPlay = 1;
+    uint32 CanPersist = 2;
+    uint32 CanRenew = 3;
+    uint32 RentalDurationSeconds = 4;
+    uint32 PlaybackDurationSeconds = 5;
+    uint32 LicenseDurationSeconds = 6;
+    uint32 RenewalRecoveryDurationSeconds = 7;
+    string RenewalServerUrl = 8;
+    uint32 RenewalDelaySeconds = 9;
+    uint32 RenewalRetryIntervalSeconds = 10;
+    uint32 RenewWithUsage = 11;
+	uint32 UnknownPolicy12 = 12;
+  }
+  message KeyContainer {
+    enum KeyType {
+      _NOKEYTYPE = 0; // dummy, added to satisfy proto3, not present in original
+      SIGNING = 1;
+      CONTENT = 2;
+      KEY_CONTROL = 3;
+      OPERATOR_SESSION = 4;
+    }
+    enum SecurityLevel {
+      _NOSECLEVEL = 0; // dummy, added to satisfy proto3, not present in original
+      SW_SECURE_CRYPTO = 1;
+      SW_SECURE_DECODE = 2;
+      HW_SECURE_CRYPTO = 3;
+      HW_SECURE_DECODE = 4;
+      HW_SECURE_ALL = 5;
+    }
+    message OutputProtection {
+      enum CGMS {
+        COPY_FREE = 0;
+        COPY_ONCE = 2;
+        COPY_NEVER = 3;
+        CGMS_NONE = 0x2A; // PC default!
+      }
+      ClientIdentification.ClientCapabilities.HdcpVersion Hdcp = 1; // it's most likely a copy of Hdcp version available here, but compiler optimized it away
+      CGMS CgmsFlags = 2;
+    }
+    message KeyControl {
+      bytes KeyControlBlock = 1; // what is this?
+      bytes Iv = 2;
+    }
+    message OperatorSessionKeyPermissions {
+      uint32 AllowEncrypt = 1;
+      uint32 AllowDecrypt = 2;
+      uint32 AllowSign = 3;
+      uint32 AllowSignatureVerify = 4;
+    }
+    message VideoResolutionConstraint {
+      uint32 MinResolutionPixels = 1;
+      uint32 MaxResolutionPixels = 2;
+      OutputProtection RequiredProtection = 3;
+    }
+    bytes Id = 1;
+    bytes Iv = 2;
+    bytes Key = 3;
+    KeyType Type = 4;
+    SecurityLevel Level = 5;
+    OutputProtection RequiredProtection = 6;
+    OutputProtection RequestedProtection = 7;
+    KeyControl _KeyControl = 8; // duped names, etc
+    OperatorSessionKeyPermissions _OperatorSessionKeyPermissions = 9; // duped names, etc
+    repeated VideoResolutionConstraint VideoResolutionConstraints = 10;
+  }
+  LicenseIdentification Id = 1;
+  Policy _Policy = 2; // duped names, etc
+  repeated KeyContainer Key = 3;
+  uint32 LicenseStartTime = 4;
+  uint32 RemoteAttestationVerified = 5; // bool?
+  bytes ProviderClientToken = 6;
+  // there might be more, check with newer versions (I see field 7-8 in a lic)
+  // this appeared in latest x86:
+  uint32 ProtectionScheme = 7; // type unconfirmed fully, but it's likely as WidevineCencHeader describesit (fourcc)
+  bytes UnknownHdcpDataField = 8;
+}
+
+message LicenseError {
+  enum Error {
+    DUMMY_NO_ERROR = 0; // dummy, added to satisfy proto3
+    INVALID_DEVICE_CERTIFICATE = 1;
+    REVOKED_DEVICE_CERTIFICATE = 2;
+    SERVICE_UNAVAILABLE = 3;
+  }
+  //LicenseRequest.RequestType ErrorCode; // clang mismatch
+  Error ErrorCode = 1;
+}
+
+message LicenseRequest {
+  message ContentIdentification {
+    message CENC {
+      // bytes Pssh = 1; // the client's definition is opaque, it doesn't care about the contents, but the PSSH has a clear definition that is understood and requested by the server, thus I'll replace it with:
+      WidevineCencHeader Pssh = 1;
+      LicenseType LicenseType = 2; // unfortunately the LicenseType symbols are not present, acceptable value seems to only be 1
+      bytes RequestId = 3;
+    }
+    message WebM {
+      bytes Header = 1; // identical to CENC, aside from PSSH and the parent field number used
+      LicenseType LicenseType = 2;
+      bytes RequestId = 3;
+    }
+    message ExistingLicense {
+      LicenseIdentification LicenseId = 1;
+      uint32 SecondsSinceStarted = 2;
+      uint32 SecondsSinceLastPlayed = 3;
+      bytes SessionUsageTableEntry = 4;
+    }
+    CENC CencId = 1;
+    WebM WebmId = 2;
+    ExistingLicense License = 3;
+  }
+  enum RequestType {
+    DUMMY_REQ_TYPE = 0; // dummy, added to satisfy proto3
+    NEW = 1;
+    RENEWAL = 2;
+    RELEASE = 3;
+  }   
+  ClientIdentification ClientId = 1;
+  ContentIdentification ContentId = 2;
+  RequestType Type = 3;
+  uint32 RequestTime = 4;
+  bytes KeyControlNonceDeprecated = 5;
+  ProtocolVersion ProtocolVersion = 6; // lacking symbols for this
+  uint32 KeyControlNonce = 7;
+  EncryptedClientIdentification EncryptedClientId = 8;
+}
+
+message ProvisionedDeviceInfo {
+  enum WvSecurityLevel {
+    LEVEL_UNSPECIFIED = 0;
+    LEVEL_1 = 1;
+    LEVEL_2 = 2;
+    LEVEL_3 = 3;
+  }
+  uint32 SystemId = 1;
+  string Soc = 2;
+  string Manufacturer = 3;
+  string Model = 4;
+  string DeviceType = 5;
+  uint32 ModelYear = 6;
+  WvSecurityLevel SecurityLevel = 7;
+  uint32 TestDevice = 8; // bool?
+} 
+
+
+// todo: fill
+message ProvisioningOptions {
+}
+
+// todo: fill
+message ProvisioningRequest {
+}
+
+// todo: fill
+message ProvisioningResponse {
+}
+
+message RemoteAttestation {
+  EncryptedClientIdentification Certificate = 1;
+  string Salt = 2;
+  string Signature = 3;
+}
+
+// todo: fill
+message SessionInit {
+}
+
+// todo: fill
+message SessionState {
+}
+
+// todo: fill
+message SignedCertificateStatusList {
+}
+
+message SignedDeviceCertificate {
+  
+  //bytes DeviceCertificate = 1; // again, they use a buffer where it's supposed to be a message, so we'll replace it with what it really is:
+  DeviceCertificate _DeviceCertificate = 1; // how should we deal with duped names? will have to look at proto docs later
+  bytes Signature = 2;
+  SignedDeviceCertificate Signer = 3;
+}
+
+
+// todo: fill
+message SignedProvisioningMessage {
+}
+
+// the root of all messages, from either server or client
+message SignedMessage {
+  enum MessageType {
+    DUMMY_MSG_TYPE = 0; // dummy, added to satisfy proto3
+    LICENSE_REQUEST = 1;
+    LICENSE = 2;
+    ERROR_RESPONSE = 3;
+    SERVICE_CERTIFICATE_REQUEST = 4;
+    SERVICE_CERTIFICATE = 5;
+  }
+  MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+  bytes Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+                 // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+  bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+  bytes SessionKey = 4; // often RSA wrapped for licenses
+  RemoteAttestation RemoteAttestation = 5;
+}
+
+
+
+// This message is copied from google's docs, not reversed:
+message WidevineCencHeader {
+  enum Algorithm {
+    UNENCRYPTED = 0;
+    AESCTR = 1;
+  };
+  Algorithm algorithm = 1;
+  repeated bytes key_id = 2;
+
+  // Content provider name.
+  string provider = 3;
+
+  // A content identifier, specified by content provider.
+  bytes content_id = 4;
+
+  // Track type. Acceptable values are SD, HD and AUDIO. Used to
+  // differentiate content keys used by an asset.
+  string track_type_deprecated = 5;
+
+  // The name of a registered policy to be used for this asset.
+  string policy = 6;
+
+  // Crypto period index, for media using key rotation.
+  uint32 crypto_period_index = 7;
+
+  // Optional protected context for group content. The grouped_license is a
+  // serialized SignedMessage.
+  bytes grouped_license = 8;
+
+  // Protection scheme identifying the encryption algorithm.
+  // Represented as one of the following 4CC values:
+  // 'cenc' (AESCTR), 'cbc1' (AESCBC),
+  // 'cens' (AESCTR subsample), 'cbcs' (AESCBC subsample).
+  uint32 protection_scheme = 9;
+
+  // Optional. For media using key rotation, this represents the duration
+  // of each crypto period in seconds.
+  uint32 crypto_period_seconds = 10;
+}
+
+
+
+
+// from here on, it's just for testing, these messages don't exist in the binaries, I'm adding them to avoid detecting type programmatically
+message SignedLicenseRequest {
+  enum MessageType {
+    DUMMY_MSG_TYPE = 0; // dummy, added to satisfy proto3
+    LICENSE_REQUEST = 1;
+    LICENSE = 2;
+    ERROR_RESPONSE = 3;
+    SERVICE_CERTIFICATE_REQUEST = 4;
+    SERVICE_CERTIFICATE = 5;
+  }
+  MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+  LicenseRequest Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+                 // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+  bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+  bytes SessionKey = 4; // often RSA wrapped for licenses
+  RemoteAttestation RemoteAttestation = 5;
+}
+
+message SignedLicense {
+  enum MessageType {
+    DUMMY_MSG_TYPE = 0; // dummy, added to satisfy proto3
+    LICENSE_REQUEST = 1;
+    LICENSE = 2;
+    ERROR_RESPONSE = 3;
+    SERVICE_CERTIFICATE_REQUEST = 4;
+    SERVICE_CERTIFICATE = 5;
+  }
+  MessageType Type = 1; // has in incorrect overlap with License_KeyContainer_SecurityLevel
+  License Msg = 2; // this has to be casted dynamically, to LicenseRequest, License or LicenseError (? unconfirmed), for Request, no other fields but Type need to be present
+                 // for SERVICE_CERTIFICATE, only Type and Msg are present, and it's just a DeviceCertificate with CertificateType set to SERVICE
+  bytes Signature = 3; // might be different type of signatures (ex. RSA vs AES CMAC(??), unconfirmed for now)
+  bytes SessionKey = 4; // often RSA wrapped for licenses
+  RemoteAttestation RemoteAttestation = 5;
+}
--- a/pywidevine/L3/cdm/formats/wv_proto3_pb2.py
+++ b/pywidevine/L3/cdm/formats/wv_proto3_pb2.py
--- a/pywidevine/L3/cdm/key.py
+++ b/pywidevine/L3/cdm/key.py
@ -0,0 +1,14 @@
+import binascii
+
+class Key:
+    def __init__(self, kid, type, key, permissions=[]):
+        self.kid = kid
+        self.type = type
+        self.key = key
+        self.permissions = permissions
+
+    def __repr__(self):
+        if self.type == "OPERATOR_SESSION":
+           return "key(kid={}, type={}, key={}, permissions={})".format(self.kid, self.type, binascii.hexlify(self.key), self.permissions)
+        else:
+           return "key(kid={}, type={}, key={})".format(self.kid, self.type, binascii.hexlify(self.key))
--- a/pywidevine/L3/cdm/session.py
+++ b/pywidevine/L3/cdm/session.py
@ -0,0 +1,18 @@
+class Session:
+    def __init__(self, session_id, init_data, device_config, offline):
+        self.session_id = session_id
+        self.init_data = init_data
+        self.offline = offline
+        self.device_config = device_config
+        self.device_key = None
+        self.session_key = None
+        self.derived_keys = {
+            'enc': None,
+            'auth_1': None,
+            'auth_2': None
+        }
+        self.license_request = None
+        self.license = None
+        self.service_certificate = None
+        self.privacy_mode = False
+        self.keys = []
--- a/pywidevine/L3/cdm/vmp.py
+++ b/pywidevine/L3/cdm/vmp.py
@ -0,0 +1,102 @@
+try:
+  from google.protobuf.internal.decoder import _DecodeVarint as _di # this was tested to work with protobuf 3, but it's an internal API (any varint decoder might work)
+except ImportError:
+  # this is generic and does not depend on pb internals, however it will decode "larger" possible numbers than pb decoder which has them fixed
+  def LEB128_decode(buffer, pos, limit = 64):
+    result = 0
+    shift = 0
+    while True:
+      b = buffer[pos]
+      pos += 1  
+      result |= ((b & 0x7F) << shift)
+      if not (b & 0x80): 
+         return (result, pos)
+      shift += 7
+      if shift > limit: 
+         raise Exception("integer too large, shift: {}".format(shift))
+  _di = LEB128_decode
+
+
+class FromFileMixin:
+  @classmethod
+  def from_file(cls, filename):
+    """Load given a filename"""
+    with open(filename,"rb") as f:
+      return cls(f.read())
+
+# the signatures use a format internally similar to 
+# protobuf's encoding, but without wire types
+class VariableReader(FromFileMixin):
+  """Protobuf-like encoding reader"""
+
+  def __init__(self, buf):
+      self.buf = buf
+      self.pos = 0
+      self.size = len(buf)
+ 
+  def read_int(self):
+    """Read a variable length integer"""
+    # _DecodeVarint will take care of out of range errors
+    (val, nextpos) = _di(self.buf, self.pos)
+    self.pos = nextpos
+    return val
+
+  def read_bytes_raw(self, size):      
+    """Read size bytes"""
+    b = self.buf[self.pos:self.pos+size]
+    self.pos += size
+    return b
+
+  def read_bytes(self):
+    """Read a bytes object""" 
+    size = self.read_int()
+    return self.read_bytes_raw(size)
+
+  def is_end(self):
+    return (self.size == self.pos)
+
+   
+class TaggedReader(VariableReader):
+  """Tagged reader, needed for implementing a WideVine signature reader"""
+
+  def read_tag(self):
+    """Read a tagged buffer"""
+    return (self.read_int(), self.read_bytes())
+
+  def read_all_tags(self, max_tag=3):
+      tags = {}
+      while (not self.is_end()):
+        (tag, bytes) = self.read_tag()
+        if (tag > max_tag):
+           raise IndexError("tag out of bound: got {}, max {}".format(tag, max_tag))
+
+        tags[tag] = bytes
+      return tags
+
+class WideVineSignatureReader(FromFileMixin):
+  """Parses a widevine .sig signature file."""
+
+  SIGNER_TAG = 1
+  SIGNATURE_TAG = 2
+  ISMAINEXE_TAG = 3
+
+  def __init__(self, buf):
+      reader = TaggedReader(buf)
+      self.version = reader.read_int()
+      if (self.version != 0):
+         raise Exception("Unsupported signature format version {}".format(self.version))
+      self.tags = reader.read_all_tags()
+
+      self.signer = self.tags[self.SIGNER_TAG]
+      self.signature = self.tags[self.SIGNATURE_TAG]
+
+      extra = self.tags[self.ISMAINEXE_TAG]
+      if (len(extra) != 1 or (extra[0] > 1)):
+         raise Exception("Unexpected 'ismainexe' field value (not '\\x00' or '\\x01'), please check: {0}".format(extra))
+      
+      self.mainexe = bool(extra[0])
+
+  @classmethod
+  def get_tags(cls, filename):
+    """Return a dictionary of each tag in the signature file"""
+    return cls.from_file(filename).tags
--- a/pywidevine/L3/decrypt/init.py
+++ b/pywidevine/L3/decrypt/init.py
--- a/pywidevine/L3/decrypt/pycache/init.cpython-37.pyc
+++ b/pywidevine/L3/decrypt/pycache/init.cpython-37.pyc
--- a/pywidevine/L3/decrypt/pycache/init.cpython-39.pyc
+++ b/pywidevine/L3/decrypt/pycache/init.cpython-39.pyc
--- a/pywidevine/L3/decrypt/pycache/wvdecryptcustom.cpython-37.pyc
+++ b/pywidevine/L3/decrypt/pycache/wvdecryptcustom.cpython-37.pyc
--- a/pywidevine/L3/decrypt/pycache/wvdecryptcustom.cpython-39.pyc
+++ b/pywidevine/L3/decrypt/pycache/wvdecryptcustom.cpython-39.pyc
--- a/pywidevine/L3/decrypt/wvdecryptcustom.py
+++ b/pywidevine/L3/decrypt/wvdecryptcustom.py
@ -0,0 +1,59 @@
+# uncompyle6 version 3.7.3
+# Python bytecode 3.6 (3379)
+# Decompiled from: Python 3.7.8 (tags/v3.7.8:4b47a5b6ba, Jun 28 2020, 08:53:46) [MSC v.1916 64 bit (AMD64)]
+# Embedded file name: pywidevine\decrypt\wvdecryptcustom.py
+import logging, subprocess, re, base64
+from pywidevine.L3.cdm import cdm, deviceconfig
+
+class WvDecrypt(object):
+    WV_SYSTEM_ID = [
+     237, 239, 139, 169, 121, 214, 74, 206, 163, 200, 39, 220, 213, 29, 33, 237]
+
+    def __init__(self, init_data_b64, cert_data_b64, device):
+        self.init_data_b64 = init_data_b64
+        self.cert_data_b64 = cert_data_b64
+        self.device = device
+        self.cdm = cdm.Cdm()
+
+        def check_pssh(pssh_b64):
+            pssh = base64.b64decode(pssh_b64)
+            if not pssh[12:28] == bytes(self.WV_SYSTEM_ID):
+                new_pssh = bytearray([0, 0, 0])
+                new_pssh.append(32 + len(pssh))
+                new_pssh[4:] = bytearray(b'pssh')
+                new_pssh[8:] = [0, 0, 0, 0]
+                new_pssh[13:] = self.WV_SYSTEM_ID
+                new_pssh[29:] = [0, 0, 0, 0]
+                new_pssh[31] = len(pssh)
+                new_pssh[32:] = pssh
+                return base64.b64encode(new_pssh)
+            else:
+                return pssh_b64
+
+        self.session = self.cdm.open_session(check_pssh(self.init_data_b64), deviceconfig.DeviceConfig(self.device))
+        if self.cert_data_b64:
+            self.cdm.set_service_certificate(self.session, self.cert_data_b64)
+
+    def log_message(self, msg):
+        return '{}'.format(msg)
+
+    def start_process(self):
+        keyswvdecrypt = []
+        try:
+            for key in self.cdm.get_keys(self.session):
+                if key.type == 'CONTENT':
+                    keyswvdecrypt.append(self.log_message('{}:{}'.format(key.kid.hex(), key.key.hex())))
+
+        except Exception:
+            return (
+             False, keyswvdecrypt)
+        else:
+            return (
+             True, keyswvdecrypt)
+
+    def get_challenge(self):
+        return self.cdm.get_license_request(self.session)
+
+    def update_license(self, license_b64):
+        self.cdm.provide_license(self.session, license_b64)
+        return True
--- a/pywidevine/L3/getPSSH.py
+++ b/pywidevine/L3/getPSSH.py
@ -0,0 +1,14 @@
+import requests, xmltodict, json
+
+def get_pssh(mpd_url):
+    r = requests.get(url=mpd_url)
+    r.raise_for_status()
+    xml = xmltodict.parse(r.text)
+    mpd = json.loads(json.dumps(xml))
+    tracks = mpd['MPD']['Period']['AdaptationSet']
+    for video_tracks in tracks:
+        if video_tracks['@mimeType'] == 'video/mp4':
+            for t in video_tracks["ContentProtection"]:
+                if t['@schemeIdUri'].lower() == "urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed":
+                    pssh = t["cenc:pssh"]
+    return pssh