packet

Packet

Bases: OrderedDict

Packet acts like a standard python map to provide simple access to the RADIUS attributes. Since RADIUS allows for repeated attributes the value will always be a sequence. pyrad makes sure to preserve the ordering when encoding and decoding packets.

There are two ways to use the map interface: if attribute names are used pyrad take care of en-/decoding data. If the attribute type number (or a vendor ID/attribute type tuple for vendor attributes) is used you work with the raw data.

Normally you will not use this class directly, but one of the AuthPacket, AcctPacket or CoAPacket classes.

Source code in pyrad2/packet.py

class Packet(OrderedDict):
    """Packet acts like a standard python map to provide simple access
    to the RADIUS attributes. Since RADIUS allows for repeated
    attributes the value will always be a sequence. pyrad makes sure
    to preserve the ordering when encoding and decoding packets.

    There are two ways to use the map interface: if attribute
    names are used pyrad take care of en-/decoding data. If
    the attribute type number (or a vendor ID/attribute type
    tuple for vendor attributes) is used you work with the
    raw data.

    Normally you will not use this class directly, but one of the
    `AuthPacket`, `AcctPacket` or `CoAPacket` classes.
    """

    def __init__(
        self,
        code: int = 0,
        id: Optional[int] = None,
        secret: bytes = b"radsec",
        authenticator: Optional[bytes] = None,
        **attributes,
    ):
        """Initializes a Packet instance.

        Args:
            code (int): Packet type code (8 bits).
            id (int): Packet identification number (8 bits).
            secret (str): Secret needed to communicate with a RADIUS server.
            authenticator (bytes): Optional authenticator
            attributes (dict): Attributes to set in the packet
        """
        super().__init__()
        self.code = code
        if id is not None:
            self.id = id
        else:
            self.id = CreateID()
        if not isinstance(secret, bytes):
            raise TypeError("secret must be a binary string")
        self.secret = secret
        if authenticator is not None and not isinstance(authenticator, bytes):
            raise TypeError("authenticator must be a binary string")
        self.authenticator = authenticator
        self.message_authenticator = None
        self.raw_packet = None

        # injected by server when grabbing packet
        self.source: list[str]

        if "dict" in attributes:
            self.dict = attributes["dict"]

        if "packet" in attributes:
            self.raw_packet = attributes["packet"]
            self.DecodePacket(self.raw_packet)

        if "message_authenticator" in attributes:
            self.message_authenticator = attributes["message_authenticator"]

        for key, value in attributes.items():
            if key in [
                "dict",
                "fd",
                "packet",
                "message_authenticator",
            ]:
                continue
            key = key.replace("_", "-")
            self.AddAttribute(key, value)

    def add_message_authenticator(self) -> None:
        self.message_authenticator = True
        # Maintain a zero octets content for md5 and hmac calculation.
        self["Message-Authenticator"] = 16 * b"\00"

        if self.id is None:
            self.id = self.CreateID()

        if self.authenticator is None and self.code == PacketType.AccessRequest:
            self.authenticator = self.CreateAuthenticator()
            self._refresh_message_authenticator()

    def get_message_authenticator(self) -> Optional[bool]:
        self._refresh_message_authenticator()
        return self.message_authenticator

    def _refresh_message_authenticator(self):
        hmac_constructor = hmac_new(self.secret)

        # Maintain a zero octets content for md5 and hmac calculation.
        self["Message-Authenticator"] = 16 * b"\00"
        attr = self._PktEncodeAttributes()

        header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))

        hmac_constructor.update(header[0:4])
        if self.code in (
            PacketType.AccountingRequest,
            PacketType.DisconnectRequest,
            PacketType.CoARequest,
            PacketType.AccountingResponse,
        ):
            hmac_constructor.update(16 * b"\00")
        else:
            # NOTE: self.authenticator on reply packet is initialized
            #       with request authenticator by design.
            #       For AccessAccept, AccessReject and AccessChallenge
            #       it is needed use original Authenticator.
            #       For AccessAccept, AccessReject and AccessChallenge
            #       it is needed use original Authenticator.
            if self.authenticator is None:
                raise Exception("No authenticator found")
            hmac_constructor.update(self.authenticator)

        hmac_constructor.update(attr)
        self["Message-Authenticator"] = hmac_constructor.digest()

    def verify_message_authenticator(
        self,
        secret: Optional[bytes] = None,
        original_authenticator=None,
        original_code=None,
    ) -> bool:
        """Verify packet Message-Authenticator.

        Args:
            secret (bytes): The shared secret


        Returns:
            bool: False if verification failed else True
        """
        if self.message_authenticator is None:
            raise Exception("No Message-Authenticator AVP present")

        prev_ma = self["Message-Authenticator"]
        # Set zero bytes for Message-Authenticator for md5 calculation
        if secret is None and self.secret is None:
            raise Exception("Missing secret for HMAC/MD5 verification")

        if secret:
            key = secret
        else:
            key = self.secret

        # If there's a raw packet, use that to calculate the expected
        # Message-Authenticator. While the Packet class keeps multiple
        # instances of an attribute grouped together in the attribute list,
        # other applications may not. Using _PktEncodeAttributes to get
        # the attributes could therefore end up changing the attribute order
        # because of the grouping Packet does, which would cause
        # Message-Authenticator verification to fail. Using the raw packet
        # instead, if present, ensures the verification is done using the
        # attributes exactly as sent.
        if self.raw_packet:
            attr = self.raw_packet[20:]
            attr = attr.replace(prev_ma[0], 16 * b"\00")
        else:
            self["Message-Authenticator"] = 16 * b"\00"
            attr = self._PktEncodeAttributes()

        header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))

        hmac_constructor = hmac_new(key)
        hmac_constructor.update(header)
        if self.code in (
            PacketType.AccountingRequest,
            PacketType.DisconnectRequest,
            PacketType.CoARequest,
            PacketType.AccountingResponse,
        ):
            if original_code is None or original_code != PacketType.StatusServer:
                # TODO: Handle Status-Server response correctly.
                hmac_constructor.update(16 * b"\00")
        elif self.code in (
            PacketType.AccessAccept,
            PacketType.AccessChallenge,
            PacketType.AccessReject,
        ):
            if original_authenticator is None:
                if self.authenticator:
                    # NOTE: self.authenticator on reply packet is initialized
                    #       with request authenticator by design.
                    original_authenticator = self.authenticator
                else:
                    raise Exception("Missing original authenticator")

            hmac_constructor.update(original_authenticator)
        else:
            # On Access-Request and Status-Server use dynamic authenticator
            hmac_constructor.update(self.authenticator)

        hmac_constructor.update(attr)
        self["Message-Authenticator"] = prev_ma[0]
        return prev_ma[0] == hmac_constructor.digest()

    def CreateReply(self, **attributes) -> "Packet":
        """Create a new packet as a reply to this one. This method
        makes sure the authenticator and secret are copied over
        to the new instance.
        """
        return Packet(
            id=self.id,
            secret=self.secret,
            authenticator=self.authenticator,
            dict=self.dict,
            **attributes,
        )

    def _DecodeValue(self, attr: Attribute, value: bytes) -> bytes | str:
        if attr.encrypt == 2:
            # salt decrypt attribute
            value = self.SaltDecrypt(value)

        if attr.values.HasBackward(value):
            return attr.values.GetBackward(value)
        else:
            return tools.DecodeAttr(attr.type, value)

    def _EncodeValue(self, attr: Attribute, value: bytes | str) -> bytes:
        if attr.values.HasForward(value):
            result = attr.values.GetForward(value)
        else:
            result = tools.EncodeAttr(attr.type, value)

        if attr.encrypt == 2:
            # salt encrypt attribute
            result = self.SaltCrypt(result)

        return result

    def _EncodeKeyValues(self, key: Hashable, values):
        if not isinstance(key, str):
            return (key, values)

        if not isinstance(values, (list, tuple)):
            values = [values]

        key, _, tag = key.partition(":")
        attr = self.dict.attributes[key]
        key = self._EncodeKey(key)
        if tag:
            tag_bytes = struct.pack("B", int(tag))
            if attr.type == "integer":
                return (
                    key,
                    [tag_bytes + self._EncodeValue(attr, v)[1:] for v in values],
                )
            else:
                return (key, [tag_bytes + self._EncodeValue(attr, v) for v in values])
        else:
            return (key, [self._EncodeValue(attr, v) for v in values])

    def _EncodeKey(self, key: Hashable):
        if not isinstance(key, str):
            return key

        attr = self.dict.attributes[key]
        if (
            attr.vendor and not attr.is_sub_attribute
        ):  # sub attribute keys don't need vendor
            return (self.dict.vendors.GetForward(attr.vendor), attr.code)
        else:
            return attr.code

    def _DecodeKey(self, key: Hashable) -> Hashable:
        """Turn a key into a string if possible"""

        if self.dict.attrindex.HasBackward(key):
            return self.dict.attrindex.GetBackward(key)
        return key

    def AddAttribute(self, key: str, value: RadiusAttributeValue) -> None:
        """Add an attribute to the packet.

        Args:
            key (str): Attribute name or identification.
            value (Any): The attribute value.
        """
        attr = self.dict.attributes[key.partition(":")[0]]

        (key, value) = self._EncodeKeyValues(key, value)

        if attr.is_sub_attribute:
            tlv = self.setdefault(self._EncodeKey(attr.parent.name), {})
            encoded = tlv.setdefault(key, [])
        else:
            encoded = self.setdefault(key, [])

        encoded.extend(value)

    def get(self, key: Hashable, failobj: Any = None) -> Any:
        try:
            res = self.__getitem__(key)
        except KeyError:
            res = failobj
        return res

    def __getitem__(self, key: Hashable) -> dict | list:
        if not isinstance(key, str):
            return super().__getitem__(key)

        values = super().__getitem__(self._EncodeKey(key))
        attr = self.dict.attributes[key]
        if attr.type == "tlv":  # return map from sub attribute code to its values
            map_result: dict = {}
            for sub_attr_key, sub_attr_val in values.items():
                sub_attr_name = attr.sub_attributes[sub_attr_key]
                sub_attr = self.dict.attributes[sub_attr_name]
                for v in sub_attr_val:
                    map_result.setdefault(sub_attr_name, []).append(
                        self._DecodeValue(sub_attr, v)
                    )
            return map_result
        else:
            list_result: list = []
            for v in values:
                list_result.append(self._DecodeValue(attr, v))
            return list_result

    def __contains__(self, key: Hashable) -> bool:
        try:
            return super().__contains__(self._EncodeKey(key))
        except KeyError:
            return False

    has_key = __contains__

    def __delitem__(self, key: Hashable) -> None:
        super().__delitem__(self._EncodeKey(key))

    def __setitem__(self, key: Hashable, item: Any):
        if isinstance(key, str):
            (key, item) = self._EncodeKeyValues(key, item)
            super().__setitem__(key, item)
        else:
            super().__setitem__(key, item)

    def keys(self):
        return [self._DecodeKey(key) for key in OrderedDict.keys(self)]

    @staticmethod
    def CreateAuthenticator() -> bytes:
        """Create a packet authenticator. All RADIUS packets contain a sixteen
        byte authenticator which is used to authenticate replies from the
        RADIUS server and in the password hiding algorithm. This function
        returns a suitable random string that can be used as an authenticator.

        Returns:
            bytes: Valid packet authenticator
        """
        return bytes(random_generator.randrange(0, 256) for _ in range(16))

    @staticmethod
    def CreateID() -> int:
        """Create a packet ID.  All RADIUS requests have a ID which is used to
        identify a request. This is used to detect retries and replay attacks.
        This function returns a suitable random number that can be used as ID.

        Returns:
            int: ID number
        """
        return random_generator.randrange(0, 256)

    def ReplyPacket(self) -> bytes:
        """Create a ready-to-transmit authentication reply packet.
        Returns a RADIUS packet which can be directly transmitted
        to a RADIUS server. This differs with Packet() in how
        the authenticator is calculated.

        Returns:
            bytes: Raw packet
        """
        assert self.authenticator

        assert self.secret is not None

        if self.message_authenticator:
            self._refresh_message_authenticator()

        attr = self._PktEncodeAttributes()
        header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))

        authenticator = hashlib.md5(
            header[0:4] + self.authenticator + attr + self.secret
        ).digest()

        return header + authenticator + attr

    def VerifyReply(self, reply: "Packet", rawreply: Optional[bytes] = None) -> bool:
        if reply.id != self.id:
            return False

        if rawreply is None:
            rawreply = reply.ReplyPacket()

        reply._PktEncodeAttributes()
        # The Authenticator field in an Accounting-Response packet is called
        # the Response Authenticator, and contains a one-way MD5 hash
        # calculated over a stream of octets consisting of the Accounting
        # Response Code, Identifier, Length, the Request Authenticator field
        # from the Accounting-Request packet being replied to, and the
        # response attributes if any, followed by the shared secret.  The
        # resulting 16 octet MD5 hash value is stored in the Authenticator
        # field of the Accounting-Response packet.
        hash = hashlib.md5(
            rawreply[0:4] + self.authenticator + rawreply[20:] + self.secret  # type: ignore
        ).digest()

        if hash != rawreply[4:20]:
            return False
        return True

    def _PktEncodeAttribute(self, key: Hashable, value: Any):
        if isinstance(key, tuple):
            value = struct.pack("!L", key[0]) + self._PktEncodeAttribute(key[1], value)
            key = 26

        return struct.pack("!BB", key, (len(value) + 2)) + value

    def _PktEncodeTlv(self, tlv_key: str, tlv_value: Any) -> bytes:
        tlv_attr = self.dict.attributes[self._DecodeKey(tlv_key)]
        curr_avp = b""
        avps = []
        max_sub_attribute_len = max(map(lambda item: len(item[1]), tlv_value.items()))
        for i in range(max_sub_attribute_len):
            sub_attr_encoding = b""
            for code, datalst in tlv_value.items():
                if i < len(datalst):
                    sub_attr_encoding += self._PktEncodeAttribute(code, datalst[i])
            # split above 255. assuming len of one instance of all sub tlvs is lower than 255
            if (len(sub_attr_encoding) + len(curr_avp)) < 245:
                curr_avp += sub_attr_encoding
            else:
                avps.append(curr_avp)
                curr_avp = sub_attr_encoding
        avps.append(curr_avp)
        tlv_avps = []
        for avp in avps:
            value = struct.pack("!BB", tlv_attr.code, (len(avp) + 2)) + avp
            tlv_avps.append(value)
        if tlv_attr.vendor:
            vendor_avps = b""
            for avp in tlv_avps:
                vendor_avps += (
                    struct.pack(
                        "!BBL",
                        26,
                        (len(avp) + 6),
                        self.dict.vendors.GetForward(tlv_attr.vendor),
                    )
                    + avp
                )
            return vendor_avps
        else:
            return b"".join(tlv_avps)

    def _PktEncodeAttributes(self) -> bytes:
        result = b""
        for code, datalst in self.items():
            attribute = self.dict.attributes.get(self._DecodeKey(code))
            if attribute and attribute.type == "tlv":
                result += self._PktEncodeTlv(code, datalst)
            else:
                for data in datalst:
                    result += self._PktEncodeAttribute(code, data)
        return result

    def _PktDecodeVendorAttribute(self, data: bytes) -> list[tuple]:
        # Check if this packet is long enough to be in the
        # RFC2865 recommended form
        if len(data) < 6:
            return [(26, data)]

        (vendor, atype, length) = struct.unpack("!LBB", data[:6])[0:3]
        attribute = self.dict.attributes.get(self._DecodeKey((vendor, atype)))
        try:
            if attribute and attribute.type == "tlv":
                self._PktDecodeTlvAttribute((vendor, atype), data[6 : length + 4])
                tlvs = []  # tlv is added to the packet inside _PktDecodeTlvAttribute
            else:
                tlvs = [((vendor, atype), data[6 : length + 4])]
        except Exception:
            return [(26, data)]

        sumlength = 4 + length
        while len(data) > sumlength:
            try:
                atype, length = struct.unpack("!BB", data[sumlength : sumlength + 2])[
                    0:2
                ]
            except Exception:
                return [(26, data)]
            tlvs.append(((vendor, atype), data[sumlength + 2 : sumlength + length]))
            sumlength += length
        return tlvs

    def _PktDecodeTlvAttribute(self, code, data):
        sub_attributes = self.setdefault(code, {})
        loc = 0

        while loc < len(data):
            atype, length = struct.unpack("!BB", data[loc : loc + 2])[0:2]
            sub_attributes.setdefault(atype, []).append(data[loc + 2 : loc + length])
            loc += length

    def DecodePacket(self, packet: bytes) -> None:
        """Initialize the object from raw packet data.  Decode a packet as
        received from the network and decode it.

        Args:
            packet packet.Packet: Raw packet
        """
        try:
            (self.code, self.id, length, self.authenticator) = struct.unpack(
                "!BBH16s", packet[0:20]
            )

        except struct.error:
            raise PacketError("Packet header is corrupt")
        if len(packet) != length:
            raise PacketError("Packet has invalid length")
        if length > 8192:
            raise PacketError("Packet length is too long (%d)" % length)

        self.clear()

        packet = packet[20:]
        while packet:
            try:
                (key, attrlen) = struct.unpack("!BB", packet[0:2])
            except struct.error:
                raise PacketError("Attribute header is corrupt")

            if attrlen < 2:
                raise PacketError("Attribute length is too small (%d)" % attrlen)

            value = packet[2:attrlen]
            attribute = self.dict.attributes.get(self._DecodeKey(key))
            if key == 26:
                for key, value in self._PktDecodeVendorAttribute(value):
                    self.setdefault(key, []).append(value)
            elif key == 80:
                # POST: Message Authenticator AVP is present.
                self.message_authenticator = True
                self.setdefault(key, []).append(value)
            elif attribute and attribute.type == "tlv":
                self._PktDecodeTlvAttribute(key, value)
            else:
                self.setdefault(key, []).append(value)

            packet = packet[attrlen:]

    def _salt_en_decrypt(self, data, salt):
        result = b""
        last = self.authenticator + salt
        while data:
            hash = hashlib.md5(self.secret + last).digest()
            for i in range(16):
                result += bytes((hash[i] ^ data[i],))

            last = result[-16:]
            data = data[16:]
        return result

    def SaltCrypt(self, value) -> bytes:
        """SaltEncrypt

        Args:
            value (str): Plaintext value

        Returns:
            bytes: Obfuscated version of the value
        """

        if isinstance(value, str):
            value = value.encode("utf-8")

        if self.authenticator is None:
            # self.authenticator = self.CreateAuthenticator()
            self.authenticator = 16 * b"\x00"

        # create salt
        random_value = 32768 + random_generator.randrange(0, 32767)
        salt_raw = struct.pack("!H", random_value)

        # length prefixing
        length = struct.pack("B", len(value))
        value = length + value

        # zero padding
        if len(value) % 16 != 0:
            value += b"\x00" * (16 - (len(value) % 16))

        return salt_raw + self._salt_en_decrypt(value, salt_raw)

    def SaltDecrypt(self, value: bytes) -> bytes:
        """SaltDecrypt

        Args:
            value (bytes): encrypted value including salt

        Returns:
            bytes: Decrypted plaintext string
        """
        # extract salt
        salt = value[:2]

        # decrypt
        value = self._salt_en_decrypt(value[2:], salt)

        # remove padding
        length = value[0]
        value = value[1 : length + 1]

        return value

    def VerifyPacket(self) -> bool:
        """Verify request.

        Returns:
            bool: True if verification passed else False
        """
        assert self.raw_packet
        hash = hashlib.md5(
            self.raw_packet[0:4] + 16 * b"\x00" + self.raw_packet[20:] + self.secret
        ).digest()
        return hash == self.authenticator

__init__(code=0, id=None, secret=b'radsec', authenticator=None, **attributes)

Initializes a Packet instance.

Parameters:

Name	Type	Description	Default
code	int	Packet type code (8 bits).	0
id	int	Packet identification number (8 bits).	None
secret	str	Secret needed to communicate with a RADIUS server.	b'radsec'
authenticator	bytes	Optional authenticator	None
attributes	dict	Attributes to set in the packet	{}

Source code in pyrad2/packet.py

def __init__(
    self,
    code: int = 0,
    id: Optional[int] = None,
    secret: bytes = b"radsec",
    authenticator: Optional[bytes] = None,
    **attributes,
):
    """Initializes a Packet instance.

    Args:
        code (int): Packet type code (8 bits).
        id (int): Packet identification number (8 bits).
        secret (str): Secret needed to communicate with a RADIUS server.
        authenticator (bytes): Optional authenticator
        attributes (dict): Attributes to set in the packet
    """
    super().__init__()
    self.code = code
    if id is not None:
        self.id = id
    else:
        self.id = CreateID()
    if not isinstance(secret, bytes):
        raise TypeError("secret must be a binary string")
    self.secret = secret
    if authenticator is not None and not isinstance(authenticator, bytes):
        raise TypeError("authenticator must be a binary string")
    self.authenticator = authenticator
    self.message_authenticator = None
    self.raw_packet = None

    # injected by server when grabbing packet
    self.source: list[str]

    if "dict" in attributes:
        self.dict = attributes["dict"]

    if "packet" in attributes:
        self.raw_packet = attributes["packet"]
        self.DecodePacket(self.raw_packet)

    if "message_authenticator" in attributes:
        self.message_authenticator = attributes["message_authenticator"]

    for key, value in attributes.items():
        if key in [
            "dict",
            "fd",
            "packet",
            "message_authenticator",
        ]:
            continue
        key = key.replace("_", "-")
        self.AddAttribute(key, value)

verify_message_authenticator(secret=None, original_authenticator=None, original_code=None)

Verify packet Message-Authenticator.

Parameters:

Name	Type	Description	Default
secret	bytes	The shared secret	None

Returns:

Name	Type	Description
bool	bool	False if verification failed else True

Source code in pyrad2/packet.py

def verify_message_authenticator(
    self,
    secret: Optional[bytes] = None,
    original_authenticator=None,
    original_code=None,
) -> bool:
    """Verify packet Message-Authenticator.

    Args:
        secret (bytes): The shared secret


    Returns:
        bool: False if verification failed else True
    """
    if self.message_authenticator is None:
        raise Exception("No Message-Authenticator AVP present")

    prev_ma = self["Message-Authenticator"]
    # Set zero bytes for Message-Authenticator for md5 calculation
    if secret is None and self.secret is None:
        raise Exception("Missing secret for HMAC/MD5 verification")

    if secret:
        key = secret
    else:
        key = self.secret

    # If there's a raw packet, use that to calculate the expected
    # Message-Authenticator. While the Packet class keeps multiple
    # instances of an attribute grouped together in the attribute list,
    # other applications may not. Using _PktEncodeAttributes to get
    # the attributes could therefore end up changing the attribute order
    # because of the grouping Packet does, which would cause
    # Message-Authenticator verification to fail. Using the raw packet
    # instead, if present, ensures the verification is done using the
    # attributes exactly as sent.
    if self.raw_packet:
        attr = self.raw_packet[20:]
        attr = attr.replace(prev_ma[0], 16 * b"\00")
    else:
        self["Message-Authenticator"] = 16 * b"\00"
        attr = self._PktEncodeAttributes()

    header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))

    hmac_constructor = hmac_new(key)
    hmac_constructor.update(header)
    if self.code in (
        PacketType.AccountingRequest,
        PacketType.DisconnectRequest,
        PacketType.CoARequest,
        PacketType.AccountingResponse,
    ):
        if original_code is None or original_code != PacketType.StatusServer:
            # TODO: Handle Status-Server response correctly.
            hmac_constructor.update(16 * b"\00")
    elif self.code in (
        PacketType.AccessAccept,
        PacketType.AccessChallenge,
        PacketType.AccessReject,
    ):
        if original_authenticator is None:
            if self.authenticator:
                # NOTE: self.authenticator on reply packet is initialized
                #       with request authenticator by design.
                original_authenticator = self.authenticator
            else:
                raise Exception("Missing original authenticator")

        hmac_constructor.update(original_authenticator)
    else:
        # On Access-Request and Status-Server use dynamic authenticator
        hmac_constructor.update(self.authenticator)

    hmac_constructor.update(attr)
    self["Message-Authenticator"] = prev_ma[0]
    return prev_ma[0] == hmac_constructor.digest()

CreateReply(**attributes)

Create a new packet as a reply to this one. This method makes sure the authenticator and secret are copied over to the new instance.

Source code in pyrad2/packet.py

def CreateReply(self, **attributes) -> "Packet":
    """Create a new packet as a reply to this one. This method
    makes sure the authenticator and secret are copied over
    to the new instance.
    """
    return Packet(
        id=self.id,
        secret=self.secret,
        authenticator=self.authenticator,
        dict=self.dict,
        **attributes,
    )

AddAttribute(key, value)

Add an attribute to the packet.

Parameters:

Name	Type	Description	Default
key	str	Attribute name or identification.	required
value	Any	The attribute value.	required

Source code in pyrad2/packet.py

def AddAttribute(self, key: str, value: RadiusAttributeValue) -> None:
    """Add an attribute to the packet.

    Args:
        key (str): Attribute name or identification.
        value (Any): The attribute value.
    """
    attr = self.dict.attributes[key.partition(":")[0]]

    (key, value) = self._EncodeKeyValues(key, value)

    if attr.is_sub_attribute:
        tlv = self.setdefault(self._EncodeKey(attr.parent.name), {})
        encoded = tlv.setdefault(key, [])
    else:
        encoded = self.setdefault(key, [])

    encoded.extend(value)

CreateAuthenticator() staticmethod

Create a packet authenticator. All RADIUS packets contain a sixteen byte authenticator which is used to authenticate replies from the RADIUS server and in the password hiding algorithm. This function returns a suitable random string that can be used as an authenticator.

Returns:

Name	Type	Description
bytes	bytes	Valid packet authenticator

Source code in pyrad2/packet.py

@staticmethod
def CreateAuthenticator() -> bytes:
    """Create a packet authenticator. All RADIUS packets contain a sixteen
    byte authenticator which is used to authenticate replies from the
    RADIUS server and in the password hiding algorithm. This function
    returns a suitable random string that can be used as an authenticator.

    Returns:
        bytes: Valid packet authenticator
    """
    return bytes(random_generator.randrange(0, 256) for _ in range(16))

CreateID() staticmethod

Create a packet ID. All RADIUS requests have a ID which is used to identify a request. This is used to detect retries and replay attacks. This function returns a suitable random number that can be used as ID.

Returns:

Name	Type	Description
int	int	ID number

Source code in pyrad2/packet.py

@staticmethod
def CreateID() -> int:
    """Create a packet ID.  All RADIUS requests have a ID which is used to
    identify a request. This is used to detect retries and replay attacks.
    This function returns a suitable random number that can be used as ID.

    Returns:
        int: ID number
    """
    return random_generator.randrange(0, 256)

ReplyPacket()

Create a ready-to-transmit authentication reply packet. Returns a RADIUS packet which can be directly transmitted to a RADIUS server. This differs with Packet() in how the authenticator is calculated.

Returns:

Name	Type	Description
bytes	bytes	Raw packet

Source code in pyrad2/packet.py

def ReplyPacket(self) -> bytes:
    """Create a ready-to-transmit authentication reply packet.
    Returns a RADIUS packet which can be directly transmitted
    to a RADIUS server. This differs with Packet() in how
    the authenticator is calculated.

    Returns:
        bytes: Raw packet
    """
    assert self.authenticator

    assert self.secret is not None

    if self.message_authenticator:
        self._refresh_message_authenticator()

    attr = self._PktEncodeAttributes()
    header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))

    authenticator = hashlib.md5(
        header[0:4] + self.authenticator + attr + self.secret
    ).digest()

    return header + authenticator + attr

DecodePacket(packet)

Initialize the object from raw packet data. Decode a packet as received from the network and decode it.

Parameters:

Name	Type	Description	Default
packet	Packet	Raw packet	required

Source code in pyrad2/packet.py

def DecodePacket(self, packet: bytes) -> None:
    """Initialize the object from raw packet data.  Decode a packet as
    received from the network and decode it.

    Args:
        packet packet.Packet: Raw packet
    """
    try:
        (self.code, self.id, length, self.authenticator) = struct.unpack(
            "!BBH16s", packet[0:20]
        )

    except struct.error:
        raise PacketError("Packet header is corrupt")
    if len(packet) != length:
        raise PacketError("Packet has invalid length")
    if length > 8192:
        raise PacketError("Packet length is too long (%d)" % length)

    self.clear()

    packet = packet[20:]
    while packet:
        try:
            (key, attrlen) = struct.unpack("!BB", packet[0:2])
        except struct.error:
            raise PacketError("Attribute header is corrupt")

        if attrlen < 2:
            raise PacketError("Attribute length is too small (%d)" % attrlen)

        value = packet[2:attrlen]
        attribute = self.dict.attributes.get(self._DecodeKey(key))
        if key == 26:
            for key, value in self._PktDecodeVendorAttribute(value):
                self.setdefault(key, []).append(value)
        elif key == 80:
            # POST: Message Authenticator AVP is present.
            self.message_authenticator = True
            self.setdefault(key, []).append(value)
        elif attribute and attribute.type == "tlv":
            self._PktDecodeTlvAttribute(key, value)
        else:
            self.setdefault(key, []).append(value)

        packet = packet[attrlen:]

SaltCrypt(value)

SaltEncrypt

Parameters:

Name	Type	Description	Default
value	str	Plaintext value	required

Returns:

Name	Type	Description
bytes	bytes	Obfuscated version of the value

Source code in pyrad2/packet.py

def SaltCrypt(self, value) -> bytes:
    """SaltEncrypt

    Args:
        value (str): Plaintext value

    Returns:
        bytes: Obfuscated version of the value
    """

    if isinstance(value, str):
        value = value.encode("utf-8")

    if self.authenticator is None:
        # self.authenticator = self.CreateAuthenticator()
        self.authenticator = 16 * b"\x00"

    # create salt
    random_value = 32768 + random_generator.randrange(0, 32767)
    salt_raw = struct.pack("!H", random_value)

    # length prefixing
    length = struct.pack("B", len(value))
    value = length + value

    # zero padding
    if len(value) % 16 != 0:
        value += b"\x00" * (16 - (len(value) % 16))

    return salt_raw + self._salt_en_decrypt(value, salt_raw)

SaltDecrypt(value)

SaltDecrypt

Parameters:

Name	Type	Description	Default
value	bytes	encrypted value including salt	required

Returns:

Name	Type	Description
bytes	bytes	Decrypted plaintext string

Source code in pyrad2/packet.py

def SaltDecrypt(self, value: bytes) -> bytes:
    """SaltDecrypt

    Args:
        value (bytes): encrypted value including salt

    Returns:
        bytes: Decrypted plaintext string
    """
    # extract salt
    salt = value[:2]

    # decrypt
    value = self._salt_en_decrypt(value[2:], salt)

    # remove padding
    length = value[0]
    value = value[1 : length + 1]

    return value

VerifyPacket()

Verify request.

Returns:

Name	Type	Description
bool	bool	True if verification passed else False

Source code in pyrad2/packet.py

def VerifyPacket(self) -> bool:
    """Verify request.

    Returns:
        bool: True if verification passed else False
    """
    assert self.raw_packet
    hash = hashlib.md5(
        self.raw_packet[0:4] + 16 * b"\x00" + self.raw_packet[20:] + self.secret
    ).digest()
    return hash == self.authenticator

AuthPacket

Bases: Packet

Source code in pyrad2/packet.py

class AuthPacket(Packet):
    def __init__(
        self,
        code: int = PacketType.AccessRequest,
        id: Optional[int] = None,
        secret: bytes = b"",
        authenticator=None,
        auth_type: str = "pap",
        **attributes,
    ):
        """Initializes an AuthPacket.

        Args:
            code (int): Packet type code (8 bits).
            id (int): Packet identification number (8 bits).
            secret (str): Secret needed to communicate with a RADIUS server.
            authenticator (bytes): Optional authenticator
            auth_type (str): Defaults to `pap`.
            attributes (dict): Attributes to set in the packet
        """
        super().__init__(code, id, secret, authenticator, **attributes)
        self.auth_type = auth_type

    def CreateReply(self, **attributes) -> "AuthPacket":
        """Create a new packet as a reply to this one. This method
        makes sure the authenticator and secret are copied over
        to the new instance.
        """
        return AuthPacket(
            PacketType.AccessAccept,
            self.id,
            self.secret,
            self.authenticator,
            dict=self.dict,
            auth_type=self.auth_type,
            **attributes,
        )

    def RequestPacket(self) -> bytes:
        """Create a ready-to-transmit authentication request packet.
        Return a RADIUS packet which can be directly transmitted
        to a RADIUS server.

        Returns:
            bytes: Raw packet
        """
        if self.authenticator is None:
            self.authenticator = self.CreateAuthenticator()

        if self.id is None:
            self.id = self.CreateID()

        if self.message_authenticator:
            self._refresh_message_authenticator()

        attr = self._PktEncodeAttributes()
        if self.auth_type == "eap-md5":
            header = struct.pack(
                "!BBH16s", self.code, self.id, (20 + 18 + len(attr)), self.authenticator
            )
            digest = hmac_new(
                self.secret,
                header
                + attr
                + struct.pack("!BB16s", 80, struct.calcsize("!BB16s"), b""),
            ).digest()
            return (
                header
                + attr
                + struct.pack("!BB16s", 80, struct.calcsize("!BB16s"), digest)
            )

        header = struct.pack(
            "!BBH16s", self.code, self.id, (20 + len(attr)), self.authenticator
        )

        return header + attr

    def PwDecrypt(self, password: bytes) -> str:
        """De-Obfuscate a RADIUS password. RADIUS hides passwords in packets by
        using an algorithm based on the MD5 hash of the packet authenticator
        and RADIUS secret. This function reverses the obfuscation process.

        Although RFC2865 does not explicitly state UTF-8 for the password field,
        the rest of RFC2865 defines UTF-8 as the encoding expected for the decrypted password.

        Args:
            password (str): obfuscated form of password

        Returns:
            str: Plaintext passsword
        """
        buf = password
        pw = b""

        last = self.authenticator
        while buf:
            hash = hashlib.md5(self.secret + last).digest()  # type: ignore
            for i in range(16):
                pw += bytes((hash[i] ^ buf[i],))
            (last, buf) = (buf[:16], buf[16:])

        # This is safe even with UTF-8 encoding since no valid encoding of UTF-8
        # (other than encoding U+0000 NULL) will produce a bytestream containing 0x00 byte.
        while pw.endswith(b"\x00"):
            pw = pw[:-1]

        # If the shared secret with the client is not the same, then de-obfuscating the password
        # field may yield illegal UTF-8 bytes. Therefore, in order not to provoke an Exception here
        # (which would be not consistently generated since this will depend on the random data
        # chosen by the client) we simply ignore un-parsable UTF-8 sequences.
        return pw.decode("utf-8", errors="ignore")

    def PwCrypt(self, password: bytes) -> bytes:
        """Obfuscate password.
        RADIUS hides passwords in packets by using an algorithm
        based on the MD5 hash of the packet authenticator and RADIUS
        secret. If no authenticator has been set before calling PwCrypt
        one is created automatically. Changing the authenticator after
        setting a password that has been encrypted using this function
        will not work.

        Args:
            password (str): Plaintext password

        Returns:
            bytes: Obfuscated version of the password
        """
        if self.authenticator is None:
            self.authenticator = self.CreateAuthenticator()

        if isinstance(password, str):
            password = password.encode("utf-8")

        buf = password
        if len(password) % 16 != 0:
            buf += b"\x00" * (16 - (len(password) % 16))

        result = b""

        last = self.authenticator
        while buf:
            hash = hashlib.md5(self.secret + last).digest()
            for i in range(16):
                result += bytes((hash[i] ^ buf[i],))
            last = result[-16:]
            buf = buf[16:]

        return result

    def VerifyChapPasswd(self, userpwd: bytes) -> bool:
        """Verify RADIUS ChapPasswd

        Args:
            userpwd (str): Plaintext password

        Returns:
            bool: True if verification is ok else False
        """

        if not self.authenticator:
            self.authenticator = self.CreateAuthenticator()

        if isinstance(userpwd, str):
            userpwd = userpwd.strip().encode("utf-8")

        chap_password = tools.DecodeOctets(self.get(3)[0])
        if len(chap_password) != 17:
            return False

        chapid = chap_password[:1]
        password = chap_password[1:]

        challenge = self.authenticator
        if "CHAP-Challenge" in self:
            challenge = self["CHAP-Challenge"][0]

        return password == hashlib.md5(chapid + userpwd + challenge).digest()

    def VerifyAuthRequest(self) -> bool:
        """Verify request authenticator.

        Returns:
            bool: True if verification passed else False
        """
        if not self.raw_packet:
            raise ValueError("Raw packet not present")

        if not self.raw_packet[0] == PacketType.AccessRequest:
            return False

        return True

__init__(code=PacketType.AccessRequest, id=None, secret=b'', authenticator=None, auth_type='pap', **attributes)

Initializes an AuthPacket.

Parameters:

Name	Type	Description	Default
code	int	Packet type code (8 bits).	AccessRequest
id	int	Packet identification number (8 bits).	None
secret	str	Secret needed to communicate with a RADIUS server.	b''
authenticator	bytes	Optional authenticator	None
auth_type	str	Defaults to pap.	'pap'
attributes	dict	Attributes to set in the packet	{}

Source code in pyrad2/packet.py

def __init__(
    self,
    code: int = PacketType.AccessRequest,
    id: Optional[int] = None,
    secret: bytes = b"",
    authenticator=None,
    auth_type: str = "pap",
    **attributes,
):
    """Initializes an AuthPacket.

    Args:
        code (int): Packet type code (8 bits).
        id (int): Packet identification number (8 bits).
        secret (str): Secret needed to communicate with a RADIUS server.
        authenticator (bytes): Optional authenticator
        auth_type (str): Defaults to `pap`.
        attributes (dict): Attributes to set in the packet
    """
    super().__init__(code, id, secret, authenticator, **attributes)
    self.auth_type = auth_type

CreateReply(**attributes)

Create a new packet as a reply to this one. This method makes sure the authenticator and secret are copied over to the new instance.

Source code in pyrad2/packet.py

def CreateReply(self, **attributes) -> "AuthPacket":
    """Create a new packet as a reply to this one. This method
    makes sure the authenticator and secret are copied over
    to the new instance.
    """
    return AuthPacket(
        PacketType.AccessAccept,
        self.id,
        self.secret,
        self.authenticator,
        dict=self.dict,
        auth_type=self.auth_type,
        **attributes,
    )

RequestPacket()

Create a ready-to-transmit authentication request packet. Return a RADIUS packet which can be directly transmitted to a RADIUS server.

Returns:

Name	Type	Description
bytes	bytes	Raw packet

Source code in pyrad2/packet.py

def RequestPacket(self) -> bytes:
    """Create a ready-to-transmit authentication request packet.
    Return a RADIUS packet which can be directly transmitted
    to a RADIUS server.

    Returns:
        bytes: Raw packet
    """
    if self.authenticator is None:
        self.authenticator = self.CreateAuthenticator()

    if self.id is None:
        self.id = self.CreateID()

    if self.message_authenticator:
        self._refresh_message_authenticator()

    attr = self._PktEncodeAttributes()
    if self.auth_type == "eap-md5":
        header = struct.pack(
            "!BBH16s", self.code, self.id, (20 + 18 + len(attr)), self.authenticator
        )
        digest = hmac_new(
            self.secret,
            header
            + attr
            + struct.pack("!BB16s", 80, struct.calcsize("!BB16s"), b""),
        ).digest()
        return (
            header
            + attr
            + struct.pack("!BB16s", 80, struct.calcsize("!BB16s"), digest)
        )

    header = struct.pack(
        "!BBH16s", self.code, self.id, (20 + len(attr)), self.authenticator
    )

    return header + attr

PwDecrypt(password)

De-Obfuscate a RADIUS password. RADIUS hides passwords in packets by using an algorithm based on the MD5 hash of the packet authenticator and RADIUS secret. This function reverses the obfuscation process.

Although RFC2865 does not explicitly state UTF-8 for the password field, the rest of RFC2865 defines UTF-8 as the encoding expected for the decrypted password.

Parameters:

Name	Type	Description	Default
password	str	obfuscated form of password	required

Returns:

Name	Type	Description
str	str	Plaintext passsword

Source code in pyrad2/packet.py

def PwDecrypt(self, password: bytes) -> str:
    """De-Obfuscate a RADIUS password. RADIUS hides passwords in packets by
    using an algorithm based on the MD5 hash of the packet authenticator
    and RADIUS secret. This function reverses the obfuscation process.

    Although RFC2865 does not explicitly state UTF-8 for the password field,
    the rest of RFC2865 defines UTF-8 as the encoding expected for the decrypted password.

    Args:
        password (str): obfuscated form of password

    Returns:
        str: Plaintext passsword
    """
    buf = password
    pw = b""

    last = self.authenticator
    while buf:
        hash = hashlib.md5(self.secret + last).digest()  # type: ignore
        for i in range(16):
            pw += bytes((hash[i] ^ buf[i],))
        (last, buf) = (buf[:16], buf[16:])

    # This is safe even with UTF-8 encoding since no valid encoding of UTF-8
    # (other than encoding U+0000 NULL) will produce a bytestream containing 0x00 byte.
    while pw.endswith(b"\x00"):
        pw = pw[:-1]

    # If the shared secret with the client is not the same, then de-obfuscating the password
    # field may yield illegal UTF-8 bytes. Therefore, in order not to provoke an Exception here
    # (which would be not consistently generated since this will depend on the random data
    # chosen by the client) we simply ignore un-parsable UTF-8 sequences.
    return pw.decode("utf-8", errors="ignore")

PwCrypt(password)

Obfuscate password. RADIUS hides passwords in packets by using an algorithm based on the MD5 hash of the packet authenticator and RADIUS secret. If no authenticator has been set before calling PwCrypt one is created automatically. Changing the authenticator after setting a password that has been encrypted using this function will not work.

Parameters:

Name	Type	Description	Default
password	str	Plaintext password	required

Returns:

Name	Type	Description
bytes	bytes	Obfuscated version of the password

Source code in pyrad2/packet.py

def PwCrypt(self, password: bytes) -> bytes:
    """Obfuscate password.
    RADIUS hides passwords in packets by using an algorithm
    based on the MD5 hash of the packet authenticator and RADIUS
    secret. If no authenticator has been set before calling PwCrypt
    one is created automatically. Changing the authenticator after
    setting a password that has been encrypted using this function
    will not work.

    Args:
        password (str): Plaintext password

    Returns:
        bytes: Obfuscated version of the password
    """
    if self.authenticator is None:
        self.authenticator = self.CreateAuthenticator()

    if isinstance(password, str):
        password = password.encode("utf-8")

    buf = password
    if len(password) % 16 != 0:
        buf += b"\x00" * (16 - (len(password) % 16))

    result = b""

    last = self.authenticator
    while buf:
        hash = hashlib.md5(self.secret + last).digest()
        for i in range(16):
            result += bytes((hash[i] ^ buf[i],))
        last = result[-16:]
        buf = buf[16:]

    return result

VerifyChapPasswd(userpwd)

Verify RADIUS ChapPasswd

Parameters:

Name	Type	Description	Default
userpwd	str	Plaintext password	required

Returns:

Name	Type	Description
bool	bool	True if verification is ok else False

Source code in pyrad2/packet.py

def VerifyChapPasswd(self, userpwd: bytes) -> bool:
    """Verify RADIUS ChapPasswd

    Args:
        userpwd (str): Plaintext password

    Returns:
        bool: True if verification is ok else False
    """

    if not self.authenticator:
        self.authenticator = self.CreateAuthenticator()

    if isinstance(userpwd, str):
        userpwd = userpwd.strip().encode("utf-8")

    chap_password = tools.DecodeOctets(self.get(3)[0])
    if len(chap_password) != 17:
        return False

    chapid = chap_password[:1]
    password = chap_password[1:]

    challenge = self.authenticator
    if "CHAP-Challenge" in self:
        challenge = self["CHAP-Challenge"][0]

    return password == hashlib.md5(chapid + userpwd + challenge).digest()

VerifyAuthRequest()

Verify request authenticator.

Returns:

Name	Type	Description
bool	bool	True if verification passed else False

Source code in pyrad2/packet.py

def VerifyAuthRequest(self) -> bool:
    """Verify request authenticator.

    Returns:
        bool: True if verification passed else False
    """
    if not self.raw_packet:
        raise ValueError("Raw packet not present")

    if not self.raw_packet[0] == PacketType.AccessRequest:
        return False

    return True

AcctPacket

Bases: Packet

RADIUS accounting packets. This class is a specialization of the generic :obj:Packet class for accounting packets.

Source code in pyrad2/packet.py

class AcctPacket(Packet):
    """RADIUS accounting packets. This class is a specialization
    of the generic :obj:`Packet` class for accounting packets.
    """

    def __init__(
        self,
        code: int = PacketType.AccountingRequest,
        id: Optional[int] = None,
        secret: bytes = b"",
        authenticator: Optional[bytes] = None,
        **attributes,
    ):
        """Initializes an Accounting packet.

        Args:
            code (int): Packet type code (8 bits).
            id (int): Packet identification number (8 bits).
            secret (str): Secret needed to communicate with a RADIUS server.
            authenticator (bytes): Optional authenticator
            attributes (dict): Attributes to set in the packet
        """
        super().__init__(code, id, secret, authenticator, **attributes)

    def CreateReply(self, **attributes) -> "AcctPacket":
        """Create a new packet as a reply to this one. This method
        makes sure the authenticator and secret are copied over
        to the new instance.
        """
        return AcctPacket(
            PacketType.AccountingResponse,
            self.id,
            self.secret,
            self.authenticator,
            dict=self.dict,
            **attributes,
        )

    def VerifyAcctRequest(self) -> bool:
        """Verify request authenticator.

        Returns:
            bool: True if verification passed else False
        """
        return self.VerifyPacket()

    def RequestPacket(self) -> bytes:
        """Create a ready-to-transmit authentication request packet.
        Return a RADIUS packet which can be directly transmitted
        to a RADIUS server.

        Returns:
            bytes: Raw packet
        """

        if self.id is None:
            self.id = self.CreateID()

        if self.message_authenticator:
            self._refresh_message_authenticator()

        attr = self._PktEncodeAttributes()
        header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))
        self.authenticator = hashlib.md5(
            header[0:4] + 16 * b"\x00" + attr + self.secret
        ).digest()

        ans = header + self.authenticator + attr

        return ans

__init__(code=PacketType.AccountingRequest, id=None, secret=b'', authenticator=None, **attributes)

Initializes an Accounting packet.

Parameters:

Name	Type	Description	Default
code	int	Packet type code (8 bits).	AccountingRequest
id	int	Packet identification number (8 bits).	None
secret	str	Secret needed to communicate with a RADIUS server.	b''
authenticator	bytes	Optional authenticator	None
attributes	dict	Attributes to set in the packet	{}

Source code in pyrad2/packet.py

def __init__(
    self,
    code: int = PacketType.AccountingRequest,
    id: Optional[int] = None,
    secret: bytes = b"",
    authenticator: Optional[bytes] = None,
    **attributes,
):
    """Initializes an Accounting packet.

    Args:
        code (int): Packet type code (8 bits).
        id (int): Packet identification number (8 bits).
        secret (str): Secret needed to communicate with a RADIUS server.
        authenticator (bytes): Optional authenticator
        attributes (dict): Attributes to set in the packet
    """
    super().__init__(code, id, secret, authenticator, **attributes)

CreateReply(**attributes)

Create a new packet as a reply to this one. This method makes sure the authenticator and secret are copied over to the new instance.

Source code in pyrad2/packet.py

def CreateReply(self, **attributes) -> "AcctPacket":
    """Create a new packet as a reply to this one. This method
    makes sure the authenticator and secret are copied over
    to the new instance.
    """
    return AcctPacket(
        PacketType.AccountingResponse,
        self.id,
        self.secret,
        self.authenticator,
        dict=self.dict,
        **attributes,
    )

VerifyAcctRequest()

Verify request authenticator.

Returns:

Name	Type	Description
bool	bool	True if verification passed else False

Source code in pyrad2/packet.py

def VerifyAcctRequest(self) -> bool:
    """Verify request authenticator.

    Returns:
        bool: True if verification passed else False
    """
    return self.VerifyPacket()

RequestPacket()

Create a ready-to-transmit authentication request packet. Return a RADIUS packet which can be directly transmitted to a RADIUS server.

Returns:

Name	Type	Description
bytes	bytes	Raw packet

Source code in pyrad2/packet.py

def RequestPacket(self) -> bytes:
    """Create a ready-to-transmit authentication request packet.
    Return a RADIUS packet which can be directly transmitted
    to a RADIUS server.

    Returns:
        bytes: Raw packet
    """

    if self.id is None:
        self.id = self.CreateID()

    if self.message_authenticator:
        self._refresh_message_authenticator()

    attr = self._PktEncodeAttributes()
    header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))
    self.authenticator = hashlib.md5(
        header[0:4] + 16 * b"\x00" + attr + self.secret
    ).digest()

    ans = header + self.authenticator + attr

    return ans

CoAPacket

Bases: Packet

RADIUS CoA packets. This class is a specialization of the generic :obj:Packet class for CoA packets.

Source code in pyrad2/packet.py

class CoAPacket(Packet):
    """RADIUS CoA packets. This class is a specialization
    of the generic :obj:`Packet` class for CoA packets.
    """

    def __init__(
        self,
        code: int = PacketType.CoARequest,
        id: Optional[int] = None,
        secret: bytes = b"",
        authenticator: Optional[bytes] = None,
        **attributes,
    ):
        """Initializes a CoA packet.

        Args:
            code (int): Packet type code (8 bits).
            id (int): Packet identification number (8 bits).
            secret (str): Secret needed to communicate with a RADIUS server.
            authenticator (bytes): Optional authenticator
            attributes (dict): Attributes to set in the packet
        """
        super().__init__(code, id, secret, authenticator, **attributes)

    def CreateReply(self, **attributes) -> "CoAPacket":
        """Create a new packet as a reply to this one. This method
        makes sure the authenticator and secret are copied over
        to the new instance.
        """
        return CoAPacket(
            PacketType.CoAACK,
            self.id,
            self.secret,
            self.authenticator,
            dict=self.dict,
            **attributes,
        )

    def VerifyCoARequest(self) -> bool:
        """Verify request authenticator.

        :return: True if verification passed else False
        :rtype: boolean
        """
        return self.VerifyPacket()

    def RequestPacket(self) -> bytes:
        """Create a ready-to-transmit CoA request packet.
        Return a RADIUS packet which can be directly transmitted
        to a RADIUS server.

        :return: raw packet
        :rtype:  string
        """

        attr = self._PktEncodeAttributes()

        if self.id is None:
            self.id = self.CreateID()

        header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))
        self.authenticator = hashlib.md5(
            header[0:4] + 16 * b"\x00" + attr + self.secret
        ).digest()

        if self.message_authenticator:
            self._refresh_message_authenticator()
            attr = self._PktEncodeAttributes()
            self.authenticator = hashlib.md5(
                header[0:4] + 16 * b"\x00" + attr + self.secret
            ).digest()

        return header + self.authenticator + attr

__init__(code=PacketType.CoARequest, id=None, secret=b'', authenticator=None, **attributes)

Initializes a CoA packet.

Parameters:

Name	Type	Description	Default
code	int	Packet type code (8 bits).	CoARequest
id	int	Packet identification number (8 bits).	None
secret	str	Secret needed to communicate with a RADIUS server.	b''
authenticator	bytes	Optional authenticator	None
attributes	dict	Attributes to set in the packet	{}

Source code in pyrad2/packet.py

def __init__(
    self,
    code: int = PacketType.CoARequest,
    id: Optional[int] = None,
    secret: bytes = b"",
    authenticator: Optional[bytes] = None,
    **attributes,
):
    """Initializes a CoA packet.

    Args:
        code (int): Packet type code (8 bits).
        id (int): Packet identification number (8 bits).
        secret (str): Secret needed to communicate with a RADIUS server.
        authenticator (bytes): Optional authenticator
        attributes (dict): Attributes to set in the packet
    """
    super().__init__(code, id, secret, authenticator, **attributes)

CreateReply(**attributes)

Create a new packet as a reply to this one. This method makes sure the authenticator and secret are copied over to the new instance.

Source code in pyrad2/packet.py

def CreateReply(self, **attributes) -> "CoAPacket":
    """Create a new packet as a reply to this one. This method
    makes sure the authenticator and secret are copied over
    to the new instance.
    """
    return CoAPacket(
        PacketType.CoAACK,
        self.id,
        self.secret,
        self.authenticator,
        dict=self.dict,
        **attributes,
    )

VerifyCoARequest()

Verify request authenticator.

:return: True if verification passed else False :rtype: boolean

Source code in pyrad2/packet.py

def VerifyCoARequest(self) -> bool:
    """Verify request authenticator.

    :return: True if verification passed else False
    :rtype: boolean
    """
    return self.VerifyPacket()

RequestPacket()

Create a ready-to-transmit CoA request packet. Return a RADIUS packet which can be directly transmitted to a RADIUS server.

:return: raw packet :rtype: string

Source code in pyrad2/packet.py

def RequestPacket(self) -> bytes:
    """Create a ready-to-transmit CoA request packet.
    Return a RADIUS packet which can be directly transmitted
    to a RADIUS server.

    :return: raw packet
    :rtype:  string
    """

    attr = self._PktEncodeAttributes()

    if self.id is None:
        self.id = self.CreateID()

    header = struct.pack("!BBH", self.code, self.id, (20 + len(attr)))
    self.authenticator = hashlib.md5(
        header[0:4] + 16 * b"\x00" + attr + self.secret
    ).digest()

    if self.message_authenticator:
        self._refresh_message_authenticator()
        attr = self._PktEncodeAttributes()
        self.authenticator = hashlib.md5(
            header[0:4] + 16 * b"\x00" + attr + self.secret
        ).digest()

    return header + self.authenticator + attr

CreateID()

Generate a packet ID.

:return: packet ID :rtype: 8 bit integer

Source code in pyrad2/packet.py

def CreateID() -> int:
    """Generate a packet ID.

    :return: packet ID
    :rtype:  8 bit integer
    """
    global CurrentID

    CurrentID = (CurrentID + 1) % 256
    return CurrentID