Files
radius-rs/radius/src/core/packet.rs

588 lines
21 KiB
Rust

use std::convert::TryInto;
use rand::Rng;
use thiserror::Error;
use crate::core::attributes::Attributes;
use crate::core::avp::{AVPType, AVP};
use crate::core::code::Code;
const MAX_PACKET_LENGTH: usize = 4096;
const RADIUS_PACKET_HEADER_LENGTH: usize = 20; // i.e. minimum packet length
#[derive(Error, Debug, PartialEq)]
pub enum PacketError {
/// An error indicates the entire length of the given packet has insufficient length.
#[error("RADIUS packet doesn't have enough length of bytes; it has to be at least {0} bytes, but actual length was {1}")]
InsufficientPacketPayloadLengthError(usize, usize),
/// An error indicates the length that is instructed by a header is insufficient.
#[error("RADIUS packet header indicates the length as {0} bytes, but this is insufficient; this must have {1} bytes at least")]
InsufficientHeaderDefinedPacketLengthError(usize, usize),
/// An error indicates the length that is instructed by a header exceeds the maximum length of the RADIUS packet.
#[error("RADIUS packet header indicates the length as {0} bytes, but this exceeds the maximum length {1} bytes")]
HeaderDefinedPacketLengthExceedsMaximumLimitError(usize, usize),
/// An error that is raised when an error has been occurred on decoding bytes for a packet.
#[error("failed to decode the packet: {0}")]
DecodingError(String),
/// An error that is raised when an error has been occurred on encoding a packet into bytes.
#[error("failed to encode the packet: {0}")]
EncodingError(String),
/// An error that is raised when it received unknown packet type code of RADIUS.
#[error("Unknown RADIUS packet type code: {0}")]
UnknownCodeError(String),
}
/// This struct represents a packet of RADIUS for request and response.
#[derive(Debug, Clone, PartialEq)]
pub struct Packet {
code: Code,
identifier: u8,
authenticator: Vec<u8>,
secret: Vec<u8>,
attributes: Attributes,
}
impl Packet {
/// Constructor for a Packet.
///
/// By default, this constructor makes an instance with a random identifier value.
/// If you'd like to set an arbitrary identifier, please use `new_with_identifier()` constructor instead or `set_identifier()` method for created instance.
pub fn new(code: Code, secret: &[u8]) -> Self {
Self::_new(code, secret, None)
}
/// Constructor for a Packet with arbitrary identifier value.
///
/// If you want to make an instance with a random identifier value, please consider using `new()`.
pub fn new_with_identifier(code: Code, secret: &[u8], identifier: u8) -> Self {
Self::_new(code, secret, Some(identifier))
}
fn _new(code: Code, secret: &[u8], maybe_identifier: Option<u8>) -> Self {
let mut rng = rand::thread_rng();
let authenticator = (0..16).map(|_| rng.gen()).collect::<Vec<u8>>();
Packet {
code: code.to_owned(),
identifier: match maybe_identifier {
Some(ident) => ident,
None => rng.gen(),
},
authenticator,
secret: secret.to_owned(),
attributes: Attributes(vec![]),
}
}
pub fn get_code(&self) -> Code {
self.code
}
pub fn get_identifier(&self) -> u8 {
self.identifier
}
pub fn get_secret(&self) -> &Vec<u8> {
&self.secret
}
pub fn get_authenticator(&self) -> &Vec<u8> {
&self.authenticator
}
/// This sets an identifier value to an instance.
pub fn set_identifier(&mut self, identifier: u8) {
self.identifier = identifier;
}
/// This decodes bytes into a Packet.
pub fn decode(bs: &[u8], secret: &[u8]) -> Result<Self, PacketError> {
if bs.len() < RADIUS_PACKET_HEADER_LENGTH {
return Err(PacketError::InsufficientPacketPayloadLengthError(
RADIUS_PACKET_HEADER_LENGTH,
bs.len(),
));
}
let len = match bs[2..4].try_into() {
Ok(v) => u16::from_be_bytes(v),
Err(e) => return Err(PacketError::DecodingError(e.to_string())),
} as usize;
if len < RADIUS_PACKET_HEADER_LENGTH {
return Err(PacketError::InsufficientHeaderDefinedPacketLengthError(
len,
RADIUS_PACKET_HEADER_LENGTH,
));
}
if len > MAX_PACKET_LENGTH {
return Err(
PacketError::HeaderDefinedPacketLengthExceedsMaximumLimitError(
len,
MAX_PACKET_LENGTH,
),
);
}
if bs.len() < len {
return Err(PacketError::InsufficientPacketPayloadLengthError(
len,
bs.len(),
));
}
let attributes = match Attributes::decode(&bs[RADIUS_PACKET_HEADER_LENGTH..len].to_vec()) {
Ok(attributes) => attributes,
Err(e) => return Err(PacketError::DecodingError(e)),
};
Ok(Packet {
code: Code::from(bs[0]),
identifier: bs[1],
authenticator: bs[4..RADIUS_PACKET_HEADER_LENGTH].to_owned(),
secret: secret.to_owned(),
attributes,
})
}
/// This method makes a response packet according to self (i.e. request packet).
pub fn make_response_packet(&self, code: Code) -> Self {
Packet {
code,
identifier: self.identifier,
authenticator: self.authenticator.clone(),
secret: self.secret.clone(),
attributes: Attributes(vec![]),
}
}
/// This method encodes the Packet into bytes.
pub fn encode(&self) -> Result<Vec<u8>, PacketError> {
let mut bs = match self.marshal_binary() {
Ok(bs) => bs,
Err(e) => return Err(PacketError::EncodingError(e)),
};
match self.code {
Code::AccessRequest | Code::StatusServer => Ok(bs),
Code::AccessAccept
| Code::AccessReject
| Code::AccountingRequest
| Code::AccountingResponse
| Code::AccessChallenge
| Code::DisconnectRequest
| Code::DisconnectACK
| Code::DisconnectNAK
| Code::CoARequest
| Code::CoAACK
| Code::CoANAK => {
let mut buf: Vec<u8> = bs[..4].to_vec();
match self.code {
Code::AccountingRequest | Code::DisconnectRequest | Code::CoARequest => {
buf.extend(vec![
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
]);
}
_ => {
buf.extend(self.authenticator.clone()); // TODO take from `bs`?
}
}
buf.extend(bs[RADIUS_PACKET_HEADER_LENGTH..].to_vec());
buf.extend(&self.secret);
bs.splice(4..20, md5::compute(&buf).to_vec());
Ok(bs)
}
_ => Err(PacketError::UnknownCodeError(format!("{:?}", self.code))),
}
}
/*
* Binary structure:
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Code | Identifier | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* | Authenticator |
* | |
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Attributes ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-
*/
fn marshal_binary(&self) -> Result<Vec<u8>, String> {
let encoded_avp = match self.attributes.encode() {
Ok(encoded) => encoded,
Err(e) => return Err(e),
};
let size = RADIUS_PACKET_HEADER_LENGTH as u16 + encoded_avp.len() as u16;
if size as usize > MAX_PACKET_LENGTH {
return Err("packet is too large".to_owned());
}
let mut bs: Vec<u8> = Vec::new();
bs.push(self.code as u8);
bs.push(self.identifier);
bs.extend(u16::to_be_bytes(size).to_vec());
bs.extend(self.authenticator.to_vec());
bs.extend(match self.attributes.encode() {
Ok(encoded) => encoded,
Err(e) => return Err(e),
});
Ok(bs)
}
/// Returns whether the Packet is authentic response or not.
pub fn is_authentic_response(response: &[u8], request: &[u8], secret: &[u8]) -> bool {
if response.len() < RADIUS_PACKET_HEADER_LENGTH
|| request.len() < RADIUS_PACKET_HEADER_LENGTH
|| secret.is_empty()
{
return false;
}
md5::compute(
[
&response[..4],
&request[4..RADIUS_PACKET_HEADER_LENGTH],
&response[RADIUS_PACKET_HEADER_LENGTH..],
&secret,
]
.concat(),
)
.to_vec()
.eq(&response[4..RADIUS_PACKET_HEADER_LENGTH].to_vec())
}
/// Returns whether the Packet is authentic request or not.
pub fn is_authentic_request(request: &[u8], secret: &[u8]) -> bool {
if request.len() < RADIUS_PACKET_HEADER_LENGTH || secret.is_empty() {
return false;
}
match Code::from(request[0]) {
Code::AccessRequest | Code::StatusServer => true,
Code::AccountingRequest | Code::DisconnectRequest | Code::CoARequest => md5::compute(
[
&request[..4],
&[
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
],
&request[RADIUS_PACKET_HEADER_LENGTH..],
&secret,
]
.concat(),
)
.to_vec()
.eq(&request[4..RADIUS_PACKET_HEADER_LENGTH].to_vec()),
_ => false,
}
}
/// Add an AVP to the list of AVPs.
pub fn add(&mut self, avp: AVP) {
self.attributes.add(avp);
}
/// Add AVPs to the list of AVPs.
pub fn extend(&mut self, avps: Vec<AVP>) {
self.attributes.extend(avps)
}
/// Delete all of AVPs from the list according to given AVP type.
pub fn delete(&mut self, typ: AVPType) {
self.attributes.del(typ);
}
/// Returns an AVP that matches at first with the given AVP type. If there are not any matched ones, this returns `None`.
pub fn lookup(&self, typ: AVPType) -> Option<&AVP> {
self.attributes.lookup(typ)
}
/// Returns AVPs that match with the given AVP type.
pub fn lookup_all(&self, typ: AVPType) -> Vec<&AVP> {
self.attributes.lookup_all(typ)
}
}
#[cfg(test)]
mod tests {
use std::net::Ipv4Addr;
use crate::core::avp::AVP;
use crate::core::code::Code;
use crate::core::packet::{
Packet, PacketError, MAX_PACKET_LENGTH, RADIUS_PACKET_HEADER_LENGTH,
};
use crate::core::rfc2865;
#[test]
fn test_for_rfc2865_7_1() -> Result<(), PacketError> {
// ref: https://tools.ietf.org/html/rfc2865#section-7.1
let secret: Vec<u8> = "xyzzy5461".as_bytes().to_vec();
let request: Vec<u8> = vec![
0x01, 0x00, 0x00, 0x38, 0x0f, 0x40, 0x3f, 0x94, 0x73, 0x97, 0x80, 0x57, 0xbd, 0x83,
0xd5, 0xcb, 0x98, 0xf4, 0x22, 0x7a, 0x01, 0x06, 0x6e, 0x65, 0x6d, 0x6f, 0x02, 0x12,
0x0d, 0xbe, 0x70, 0x8d, 0x93, 0xd4, 0x13, 0xce, 0x31, 0x96, 0xe4, 0x3f, 0x78, 0x2a,
0x0a, 0xee, 0x04, 0x06, 0xc0, 0xa8, 0x01, 0x10, 0x05, 0x06, 0x00, 0x00, 0x00, 0x03,
];
let request_packet = Packet::decode(&request, &secret)?;
assert_eq!(request_packet.code, Code::AccessRequest);
assert_eq!(request_packet.identifier, 0);
assert_eq!(
rfc2865::lookup_user_name(&request_packet).unwrap().unwrap(),
"nemo"
);
assert_eq!(
rfc2865::lookup_all_user_name(&request_packet).unwrap(),
vec!["nemo"],
);
assert_eq!(
rfc2865::lookup_user_password(&request_packet)
.unwrap()
.unwrap(),
b"arctangent"
);
assert_eq!(
rfc2865::lookup_nas_ip_address(&request_packet)
.unwrap()
.unwrap(),
Ipv4Addr::from([192, 168, 1, 16]),
);
assert_eq!(
rfc2865::lookup_nas_port(&request_packet).unwrap().unwrap(),
3
);
assert_eq!(request_packet.encode().unwrap(), request);
assert_eq!(Packet::is_authentic_request(&request, &secret), true);
let response: Vec<u8> = vec![
0x02, 0x00, 0x00, 0x26, 0x86, 0xfe, 0x22, 0x0e, 0x76, 0x24, 0xba, 0x2a, 0x10, 0x05,
0xf6, 0xbf, 0x9b, 0x55, 0xe0, 0xb2, 0x06, 0x06, 0x00, 0x00, 0x00, 0x01, 0x0f, 0x06,
0x00, 0x00, 0x00, 0x00, 0x0e, 0x06, 0xc0, 0xa8, 0x01, 0x03,
];
let mut response_packet = request_packet.make_response_packet(Code::AccessAccept);
rfc2865::add_service_type(&mut response_packet, rfc2865::SERVICE_TYPE_LOGIN_USER);
rfc2865::add_login_service(&mut response_packet, rfc2865::LOGIN_SERVICE_TELNET);
rfc2865::add_login_ip_host(&mut response_packet, &Ipv4Addr::from([192, 168, 1, 3]));
assert_eq!(response_packet.encode().unwrap(), response);
assert_eq!(
Packet::is_authentic_response(&response, &request, &secret),
true
);
// test removing a AVP
assert_eq!(
rfc2865::lookup_service_type(&response_packet).is_some(),
true
);
rfc2865::delete_service_type(&mut response_packet);
assert_eq!(
rfc2865::lookup_service_type(&response_packet).is_some(),
false
);
Ok(())
}
#[test]
fn test_for_rfc2865_7_2() -> Result<(), PacketError> {
let secret: Vec<u8> = "xyzzy5461".as_bytes().to_vec();
let request: Vec<u8> = vec![
0x01, 0x01, 0x00, 0x47, 0x2a, 0xee, 0x86, 0xf0, 0x8d, 0x0d, 0x55, 0x96, 0x9c, 0xa5,
0x97, 0x8e, 0x0d, 0x33, 0x67, 0xa2, 0x01, 0x08, 0x66, 0x6c, 0x6f, 0x70, 0x73, 0x79,
0x03, 0x13, 0x16, 0xe9, 0x75, 0x57, 0xc3, 0x16, 0x18, 0x58, 0x95, 0xf2, 0x93, 0xff,
0x63, 0x44, 0x07, 0x72, 0x75, 0x04, 0x06, 0xc0, 0xa8, 0x01, 0x10, 0x05, 0x06, 0x00,
0x00, 0x00, 0x14, 0x06, 0x06, 0x00, 0x00, 0x00, 0x02, 0x07, 0x06, 0x00, 0x00, 0x00,
0x01,
];
let request_packet = Packet::decode(&request, &secret)?;
assert_eq!(request_packet.get_code(), Code::AccessRequest);
assert_eq!(request_packet.identifier, 1);
assert_eq!(
rfc2865::lookup_user_name(&request_packet).unwrap().unwrap(),
"flopsy"
);
assert_eq!(
rfc2865::lookup_nas_ip_address(&request_packet)
.unwrap()
.unwrap(),
Ipv4Addr::from([192, 168, 1, 16]),
);
assert_eq!(
rfc2865::lookup_nas_port(&request_packet).unwrap().unwrap(),
20
);
assert_eq!(
rfc2865::lookup_service_type(&request_packet)
.unwrap()
.unwrap(),
rfc2865::SERVICE_TYPE_FRAMED_USER,
);
assert_eq!(
rfc2865::lookup_framed_protocol(&request_packet)
.unwrap()
.unwrap(),
rfc2865::FRAMED_PROTOCOL_PPP,
);
let response: Vec<u8> = vec![
0x02, 0x01, 0x00, 0x38, 0x15, 0xef, 0xbc, 0x7d, 0xab, 0x26, 0xcf, 0xa3, 0xdc, 0x34,
0xd9, 0xc0, 0x3c, 0x86, 0x01, 0xa4, 0x06, 0x06, 0x00, 0x00, 0x00, 0x02, 0x07, 0x06,
0x00, 0x00, 0x00, 0x01, 0x08, 0x06, 0xff, 0xff, 0xff, 0xfe, 0x0a, 0x06, 0x00, 0x00,
0x00, 0x00, 0x0d, 0x06, 0x00, 0x00, 0x00, 0x01, 0x0c, 0x06, 0x00, 0x00, 0x05,
// ^ incorrectly a 2 in the document
0xdc,
];
let response_packet = Packet::decode(&response, &secret).unwrap();
assert_eq!(response_packet.get_code(), Code::AccessAccept);
assert_eq!(response_packet.get_identifier(), 1);
assert_eq!(
rfc2865::lookup_service_type(&response_packet)
.unwrap()
.unwrap(),
rfc2865::SERVICE_TYPE_FRAMED_USER
);
assert_eq!(
rfc2865::lookup_framed_protocol(&response_packet)
.unwrap()
.unwrap(),
rfc2865::FRAMED_PROTOCOL_PPP,
);
assert_eq!(
rfc2865::lookup_framed_ip_address(&response_packet)
.unwrap()
.unwrap(),
Ipv4Addr::from([255, 255, 255, 254]),
);
assert_eq!(
rfc2865::lookup_framed_routing(&response_packet)
.unwrap()
.unwrap(),
rfc2865::FRAMED_ROUTING_NONE,
);
assert_eq!(
rfc2865::lookup_framed_compression(&response_packet)
.unwrap()
.unwrap(),
rfc2865::FRAMED_COMPRESSION_VAN_JACOBSON_TCP_IP,
);
assert_eq!(
rfc2865::lookup_framed_mtu(&response_packet)
.unwrap()
.unwrap(),
1500,
);
Ok(())
}
#[test]
fn test_passwords() {
let passwords = vec![
b"".to_vec(),
b"qwerty".to_vec(),
b"helloworld1231231231231233489hegufudhsgdsfygdf8g".to_vec(),
];
let secret = b"xyzzy5461";
for password in passwords {
let mut request_packet = Packet::new(Code::AccessRequest, secret);
rfc2865::add_user_password(&mut request_packet, &password).unwrap();
let encoded = request_packet.encode().unwrap();
let decoded = Packet::decode(&encoded, secret).unwrap();
assert_eq!(
rfc2865::lookup_user_password(&decoded).unwrap().unwrap(),
password
);
}
}
#[test]
fn test_parse_invalid() {
struct TestCase<'a> {
plain_text: &'a str,
expected_error: PacketError,
};
let test_cases = &[
TestCase {
plain_text: "\x01",
expected_error: PacketError::InsufficientPacketPayloadLengthError(RADIUS_PACKET_HEADER_LENGTH, 1),
},
TestCase {
plain_text: "\x01\x7f\x00\x00\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01",
expected_error: PacketError::InsufficientHeaderDefinedPacketLengthError(0, RADIUS_PACKET_HEADER_LENGTH),
},
TestCase {
plain_text: "\x01\x7f\x7f\x7f\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01",
expected_error: PacketError::HeaderDefinedPacketLengthExceedsMaximumLimitError(32639, MAX_PACKET_LENGTH),
},
TestCase {
plain_text: "\x00\x7f\x00\x16\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x00",
expected_error: PacketError::InsufficientPacketPayloadLengthError(22, 21),
},
TestCase {
plain_text: "\x01\x01\x00\x16\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x00",
expected_error: PacketError::DecodingError("invalid attribute length".to_owned()),
}
];
let secret = b"12345";
for test_case in test_cases {
let result = Packet::decode(test_case.plain_text.as_bytes(), secret);
assert_eq!(result.is_err(), true);
assert_eq!(result.err().unwrap(), test_case.expected_error);
}
}
#[test]
fn test_packet_attribute_length_boundary() {
let mut packet = Packet::new(Code::AccessRequest, b"12345");
packet.add(AVP {
typ: 1,
value: vec![1; 253],
});
let encoded = packet.encode();
assert_eq!(encoded.is_err(), false);
let mut packet = Packet::new(Code::AccessRequest, b"12345");
packet.add(AVP {
typ: 1,
value: vec![1; 254],
});
let encoded = packet.encode();
assert_eq!(encoded.is_err(), true);
assert_eq!(
encoded.err().unwrap(),
PacketError::EncodingError("attribute is too large".to_owned()),
);
}
#[test]
fn test_with_arbitrary_identifier() {
let mut packet = Packet::new(Code::AccessRequest, b"12345");
let random_ident = packet.get_identifier();
let expected_ident = random_ident + 1;
packet.set_identifier(expected_ident);
assert_eq!(packet.get_identifier(), expected_ident);
packet = Packet::new_with_identifier(Code::AccessRequest, b"12345", expected_ident);
assert_eq!(packet.get_identifier(), expected_ident);
}
}