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// Copyright (c) 2017,2018,2020 Ivaylo Petrov // // Licensed under the MIT license <LICENSE-MIT or // http://opensource.org/licenses/MIT>, at your option. This file may not be // copied, modified, or distributed except according to those terms. // // author: Ivaylo Petrov <ivajloip@gmail.com> //! Provides types and methods for parsing LoRaWAN payloads. //! //! # Examples //! //! ``` //! use lorawan::parser::*; //! use lorawan::keys::*; //! //! let data = vec![0x40, 0x04, 0x03, 0x02, 0x01, 0x80, 0x01, 0x00, 0x01, //! 0xa6, 0x94, 0x64, 0x26, 0x15, 0xd6, 0xc3, 0xb5, 0x82]; //! if let Ok(PhyPayload::Data(DataPayload::Encrypted(phy))) = parse(data) { //! let key = AES128([1; 16]); //! let decrypted = phy.decrypt(None, Some(&key), 1).unwrap(); //! if let Ok(FRMPayload::Data(data_payload)) = //! decrypted.frm_payload() { //! println!("{}", String::from_utf8_lossy(data_payload)); //! } //! } else { //! panic!("failed to parse data payload"); //! } //! ``` use super::keys::{AES128, CryptoFactory, Encrypter, MIC}; use super::maccommands::{DLSettings, Frequency, MacCommandIterator, parse_mac_commands}; use super::securityhelpers; #[cfg(feature = "default-crypto")] use super::default_crypto::DefaultFactory; macro_rules! fixed_len_struct { ( $(#[$outer:meta])* struct $type:ident[$size:expr]; ) => { $(#[$outer])* #[derive(Debug, Eq)] pub struct $type<T: AsRef<[u8]>>(T); impl<T: AsRef<[u8]>> $type<T> { fn new_from_raw(bytes: T) -> $type<T> { $type(bytes) } pub fn new(data: T) -> Option<$type<T>> { let bytes = data.as_ref(); if bytes.len() != $size { None } else { Some($type(data)) } } } impl<T: AsRef<[u8]> + Clone> Clone for $type<T> { fn clone(&self) -> Self { Self(self.0.clone()) } } impl<T: AsRef<[u8]> + Copy> Copy for $type<T> { } impl<T: AsRef<[u8]>, V: AsRef<[u8]>> PartialEq<$type<T>> for $type<V> { fn eq(&self, other: &$type<T>) -> bool { self.as_ref() == other.as_ref() } } impl<'a> From<&'a [u8; $size]> for $type<&'a [u8; $size]> { fn from(v: &'a [u8; $size]) -> Self { $type(v) } } impl<T: AsRef<[u8]>> AsRef<[u8]> for $type<T> { fn as_ref(&self) -> &[u8] { self.0.as_ref() } } impl<T: AsRef<[u8]>> $type<T> { #[inline] pub fn to_owned(&self) -> $type<[u8; $size]> { let mut data = [0 as u8; $size]; data.copy_from_slice(self.0.as_ref()); $type(data) } } impl<T: AsRef<[u8]> + Default> Default for $type<T> { #[inline] fn default() -> $type<T> { $type(T::default()) } } }; } /// PhyPayload is a type that represents a physical LoRaWAN payload. /// /// It can either be JoinRequest, JoinAccept, or DataPayload. #[derive(Debug, PartialEq)] pub enum PhyPayload<T, F> { JoinRequest(JoinRequestPayload<T, F>), JoinAccept(JoinAcceptPayload<T, F>), Data(DataPayload<T, F>) } impl<T: AsRef<[u8]>, F> AsRef<[u8]> for PhyPayload<T, F> { fn as_ref(&self) -> &[u8] { match self { PhyPayload::JoinRequest(jr) => jr.as_bytes(), PhyPayload::JoinAccept(ja) => ja.as_bytes(), PhyPayload::Data(data) => data.as_bytes(), } } } /// JoinAcceptPayload is a type that represents a JoinAccept. /// /// It can either be encrypted for example as a result from the [parse](fn.parse.html) /// function or not. #[derive(Debug, PartialEq)] pub enum JoinAcceptPayload<T, F> { Encrypted(EncryptedJoinAcceptPayload<T, F>), Decrypted(DecryptedJoinAcceptPayload<T, F>) } impl<T: AsRef<[u8]>, F> AsPhyPayloadBytes for JoinAcceptPayload<T, F> { fn as_bytes(&self) -> &[u8] { match self { JoinAcceptPayload::Encrypted(e) => e.as_bytes(), JoinAcceptPayload::Decrypted(d) => d.as_bytes(), } } } /// DataPayload is a type that represents a ConfirmedDataUp, ConfirmedDataDown, /// UnconfirmedDataUp or UnconfirmedDataDown. /// /// It can either be encrypted for example as a result from the [parse](fn.parse.html) /// function or not. #[derive(Debug, PartialEq)] pub enum DataPayload<T, F> { Encrypted(EncryptedDataPayload<T, F>), Decrypted(DecryptedDataPayload<T>) } impl<T: AsRef<[u8]>, F> DataHeader for DataPayload<T, F> { fn as_data_bytes(&self) -> &[u8] { match self { DataPayload::Encrypted(data) => data.as_data_bytes(), DataPayload::Decrypted(data) => data.as_data_bytes() } } } /// Trait with the sole purpose to make clear distinction in some implementations between types /// that just happen to have AsRef and those that want to have the given implementations (like /// MICAble and MHDRAble). pub trait AsPhyPayloadBytes { fn as_bytes(&self) -> &[u8]; } impl AsRef<[u8]> for dyn AsPhyPayloadBytes { fn as_ref(&self) -> &[u8] { self.as_bytes() } } /// Helper trait to add mic to all types that should have it. pub trait MICAble { /// Gives the MIC of the PhyPayload. fn mic(&self) -> MIC; } impl<T: AsPhyPayloadBytes> MICAble for T { fn mic(&self) -> MIC { let data = self.as_bytes(); let len = data.len(); MIC([data[len - 4], data[len - 3], data[len - 2], data[len - 1]]) } } /// Helper trait to add mhdr to all types that should have it. pub trait MHDRAble { /// Gives the MIC of the PhyPayload. fn mhdr(&self) -> MHDR; } /// Assumes at least one byte in the data. impl<T: AsPhyPayloadBytes> MHDRAble for T { fn mhdr(&self) -> MHDR { let data = self.as_bytes(); MHDR(data[0]) } } /// JoinAcceptPayload represents a JoinRequest. /// /// It can be built either directly through the [new](#method.new) or using the /// [parse](fn.parse.html) function. #[derive(Debug, PartialEq)] pub struct JoinRequestPayload<T, F>(T, F); impl<T: AsRef<[u8]>, F> AsPhyPayloadBytes for JoinRequestPayload<T, F> { fn as_bytes(&self) -> &[u8] { self.0.as_ref() } } impl<T: AsRef<[u8]>, F: CryptoFactory> JoinRequestPayload<T, F> { /// Creates a new JoinRequestPayload if the provided data is acceptable. /// /// # Argument /// /// * data - the bytes for the payload. /// /// # Examples /// /// ``` /// let data = vec![0x00, 0x04, 0x03, 0x02, 0x01, 0x04, 0x03, 0x02, 0x01, 0x05, 0x04, 0x03, /// 0x02, 0x05, 0x04, 0x03, 0x02, 0x2d, 0x10, 0x6a, 0x99, 0x0e, 0x12]; /// let phy = lorawan::parser::JoinRequestPayload::new_with_factory(data, /// lorawan::default_crypto::DefaultFactory); /// ``` pub fn new_with_factory<'a>(data: T, factory: F) -> Result<Self, &'a str> { if !Self::can_build_from(data.as_ref()) { Err("can not build JoinRequestPayload from the provided data") } else { Ok(Self(data, factory)) } } fn can_build_from(bytes: &[u8]) -> bool { bytes.len() == 23 && MHDR(bytes[0]).mtype() == MType::JoinRequest } /// Gives the APP EUI of the JoinRequest. pub fn app_eui(&self) -> EUI64<&[u8]> { EUI64::new_from_raw(&self.0.as_ref()[1..9]) } /// Gives the DEV EUI of the JoinRequest. pub fn dev_eui(&self) -> EUI64<&[u8]> { EUI64::new_from_raw(&self.0.as_ref()[9..17]) } /// Gives the DEV Nonce of the JoinRequest. pub fn dev_nonce(&self) -> DevNonce<&[u8]> { DevNonce::new_from_raw(&self.0.as_ref()[17..19]) } /// Verifies that the JoinRequest has correct MIC. pub fn validate_mic(&self, key: &AES128) -> bool { self.mic() == self.calculate_mic(key) } fn calculate_mic(&self, key: &AES128) -> MIC { let d = self.0.as_ref(); securityhelpers::calculate_mic(&d[..d.len() - 4], self.1.new_mac(key)) } } /// EncryptedJoinAcceptPayload represents an encrypted JoinAccept. /// /// It can be built either directly through the [new](#method.new) or using the /// [parse](fn.parse.html) function. #[derive(Debug, PartialEq)] pub struct EncryptedJoinAcceptPayload<T, F>(T, F); impl<T: AsRef<[u8]>, F> AsPhyPayloadBytes for EncryptedJoinAcceptPayload<T, F> { fn as_bytes(&self) -> &[u8] { self.0.as_ref() } } impl<T: AsRef<[u8]> + AsMut<[u8]>, F: CryptoFactory> EncryptedJoinAcceptPayload<T, F> { /// Creates a new EncryptedJoinAcceptPayload if the provided data is acceptable. /// /// # Argument /// /// * data - the bytes for the payload. /// * factory - the factory that shall be used to create object for crypto functions. pub fn new_with_factory<'a>(data: T, factory: F) -> Result<Self, &'a str> { if Self::can_build_from(data.as_ref()) { Ok(Self(data, factory)) } else { Err("can not build EncryptedJoinAcceptPayload from the provided data") } } fn can_build_from(bytes: &[u8]) -> bool { (bytes.len() == 17 || bytes.len() == 33) && MHDR(bytes[0]).mtype() == MType::JoinAccept } /// Decrypts the EncryptedJoinAcceptPayload producing a DecryptedJoinAcceptPayload. /// /// This method consumes the EncryptedJoinAcceptPayload as it reuses the underlying memory. /// Please note that it does not verify the mic. /// /// # Argument /// /// * key - the key to be used for the decryption. /// /// # Examples /// /// ``` /// let mut data = vec![0x20, 0x49, 0x3e, 0xeb, 0x51, 0xfb, 0xa2, 0x11, 0x6f, 0x81, 0x0e, 0xdb, /// 0x37, 0x42, 0x97, 0x51, 0x42]; /// let phy = lorawan::parser::EncryptedJoinAcceptPayload::new(data); /// let key = lorawan::keys::AES128([0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, /// 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff]); /// let decrypted = phy.unwrap().decrypt(&key); /// ``` pub fn decrypt(mut self, key: &AES128) -> DecryptedJoinAcceptPayload<T, F> { { let bytes = self.0.as_mut(); let len = bytes.len(); let aes_enc = self.1.new_enc(key); for i in 0..(len >> 4) { let start = (i << 4) + 1; let mut block = generic_array::GenericArray::from_mut_slice(&mut bytes[start..(start + 16)]); aes_enc.encrypt_block(&mut block); } } DecryptedJoinAcceptPayload(self.0, self.1) } } /// DecryptedJoinAcceptPayload represents a decrypted JoinAccept. /// /// It can be built either directly through the [new](#method.new) or using the /// [EncryptedJoinAcceptPayload.decrypt](struct.EncryptedJoinAcceptPayload.html#method.decrypt) function. #[derive(Debug, PartialEq)] pub struct DecryptedJoinAcceptPayload<T, F>(T, F); impl<T: AsRef<[u8]>, F> AsPhyPayloadBytes for DecryptedJoinAcceptPayload<T, F> { fn as_bytes(&self) -> &[u8] { self.0.as_ref() } } impl<T: AsRef<[u8]>, F: CryptoFactory> DecryptedJoinAcceptPayload<T, F> { /// Verifies that the JoinAccept has correct MIC. pub fn validate_mic(&self, key: &AES128) -> bool { self.mic() == self.calculate_mic(key) } fn calculate_mic(&self, key: &AES128) -> MIC { let d = self.0.as_ref(); securityhelpers::calculate_mic(&d[..d.len() - 4], self.1.new_mac(key)) } /// Computes the network session key for a given device. /// /// # Argument /// /// * app_nonce - the network server nonce. /// * nwk_addr - the address of the network. /// * dev_nonce - the nonce from the device. /// * key - the app key. /// /// # Examples /// /// ``` /// let dev_nonce = vec![0xcc, 0xdd]; /// let data = vec![0x20, 0x49, 0x3e, 0xeb, 0x51, 0xfb, 0xa2, 0x11, 0x6f, 0x81, 0x0e, 0xdb, 0x37, /// 0x42, 0x97, 0x51, 0x42]; /// let app_key = lorawan::keys::AES128([0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, /// 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff]); /// let join_accept = lorawan::parser::DecryptedJoinAcceptPayload::new(data, &app_key).unwrap(); /// /// let nwk_skey = join_accept.derive_newskey( /// &lorawan::parser::DevNonce::new(&dev_nonce[..]).unwrap(), /// &app_key, /// ); /// ``` pub fn derive_newskey<TT: AsRef<[u8]>>(&self, dev_nonce: &DevNonce<TT>, key: &AES128) -> AES128 { self.derive_session_key(0x1, dev_nonce, key) } /// Computes the application session key for a given device. /// /// # Argument /// /// * app_nonce - the network server nonce. /// * nwk_addr - the address of the network. /// * dev_nonce - the nonce from the device. /// * key - the app key. /// /// # Examples /// /// ``` /// let dev_nonce = vec![0xcc, 0xdd]; /// let data = vec![0x20, 0x49, 0x3e, 0xeb, 0x51, 0xfb, 0xa2, 0x11, 0x6f, 0x81, 0x0e, 0xdb, 0x37, /// 0x42, 0x97, 0x51, 0x42]; /// let app_key = lorawan::keys::AES128([0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, /// 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff]); /// let join_accept = lorawan::parser::DecryptedJoinAcceptPayload::new(data, &app_key).unwrap(); /// /// let app_skey = join_accept.derive_appskey( /// &lorawan::parser::DevNonce::new(&dev_nonce[..]).unwrap(), /// &app_key, /// ); /// ``` pub fn derive_appskey<TT: AsRef<[u8]>>(&self, dev_nonce: &DevNonce<TT>, key: &AES128) -> AES128 { self.derive_session_key(0x2, dev_nonce, key) } fn derive_session_key<TT: AsRef<[u8]>>(&self, first_byte: u8, dev_nonce: &DevNonce<TT>, key: &AES128) -> AES128 { let cipher = self.1.new_enc(key); // note: AppNonce is 24 bit, NetId is 24 bit, DevNonce is 16 bit let app_nonce = self.app_nonce(); let nwk_addr = self.net_id(); let (app_nonce_arr, nwk_addr_arr, dev_nonce_arr) = (app_nonce.as_ref(), nwk_addr.as_ref(), dev_nonce.as_ref()); let mut block = [0u8; 16]; block[0] = first_byte; block[1] = app_nonce_arr[0]; block[2] = app_nonce_arr[1]; block[3] = app_nonce_arr[2]; block[4] = nwk_addr_arr[0]; block[5] = nwk_addr_arr[1]; block[6] = nwk_addr_arr[2]; block[7] = dev_nonce_arr[0]; block[8] = dev_nonce_arr[1]; let mut input = generic_array::GenericArray::clone_from_slice(&block); cipher.encrypt_block(&mut input); let mut output_key = [0u8; 16]; output_key.copy_from_slice(&input[0..16]); AES128(output_key) } } impl<T: AsRef<[u8]>, F> DecryptedJoinAcceptPayload<T, F> { /// Gives the app nonce of the JoinAccept. pub fn app_nonce(&self) -> AppNonce<&[u8]> { AppNonce::new_from_raw(&self.0.as_ref()[1..4]) } /// Gives the net ID of the JoinAccept. pub fn net_id(&self) -> NwkAddr<&[u8]> { NwkAddr::new_from_raw(&self.0.as_ref()[4..7]) } /// Gives the dev address of the JoinAccept. pub fn dev_addr(&self) -> DevAddr<&[u8]> { DevAddr::new_from_raw(&self.0.as_ref()[7..11]) } /// Gives the downlink configuration of the JoinAccept. pub fn dl_settings(&self) -> DLSettings { DLSettings::new(self.0.as_ref()[11]) } /// Gives the RX delay of the JoinAccept. pub fn rx_delay(&self) -> u8 { self.0.as_ref()[12] & 0x0f } /// Gives the channel frequency list of the JoinAccept. pub fn c_f_list(&self) -> Option<[Frequency; 5]> { if self.0.as_ref().len() == 17 { return None; } let d = self.0.as_ref(); let res = [Frequency::new_from_raw(&d[13..16]), Frequency::new_from_raw(&d[16..19]), Frequency::new_from_raw(&d[19..22]), Frequency::new_from_raw(&d[22..25]), Frequency::new_from_raw(&d[25..28])]; Some(res) } } impl<T: AsRef<[u8]> + AsMut<[u8]>, F: CryptoFactory> DecryptedJoinAcceptPayload<T, F> { /// Creates a DecryptedJoinAcceptPayload from the bytes of a JoinAccept. /// /// The JoinAccept payload is automatically decrypted and the mic is verified using the suplied /// crypto factory implementation. /// /// # Argument /// /// * bytes - the data from which the PhyPayload is to be built. /// * key - the key that is to be used to decrypt the payload. /// * factory - the factory that shall be used to create object for crypto functions. pub fn new_with_factory<'a, 'b>(data: T, key: &'a AES128, factory: F) -> Result<Self, &'b str> { let t = EncryptedJoinAcceptPayload::new_with_factory(data, factory)?; let res = t.decrypt(key); if res.validate_mic(key) { Ok(res) } else { Err("MIC did not match") } } } /// Helper trait for EncryptedDataPayload and DecryptedDataPayload. /// /// NOTE: Does not check the payload size as that should be done prior to building the object of /// the implementing type. pub trait DataHeader { /// Equivalent to AsRef<[u8]>. fn as_data_bytes(&self) -> &[u8]; /// Gives the FHDR of the DataPayload. fn fhdr(&self) -> FHDR { FHDR::new_from_raw(&self.as_data_bytes()[1..(1 + self.fhdr_length())], self.is_uplink()) } /// Gives whether the payload is uplink or not. fn is_uplink(&self) -> bool { let mtype = MHDR(self.as_data_bytes()[0]).mtype(); mtype == MType::UnconfirmedDataUp || mtype == MType::ConfirmedDataUp } /// Gives the FPort of the DataPayload if there is one. fn f_port(&self) -> Option<u8> { let fhdr_length = self.fhdr_length(); let data = self.as_data_bytes(); if fhdr_length + 1 >= data.len() - 5 { return None; } Some(data[1 + fhdr_length]) } /// Gives the length of the FHDR field. fn fhdr_length(&self) -> usize { fhdr_length(self.as_data_bytes()[5]) } } fn fhdr_length(b: u8) -> usize { 7 + (b & 0x0f) as usize } impl<T: DataHeader> AsPhyPayloadBytes for T { fn as_bytes(&self) -> &[u8] { self.as_data_bytes() } } /// EncryptedDataPayload represents an encrypted data payload. /// /// It can be built either directly through the [new](#method.new) or using the /// [parse](fn.parse.html) function. #[derive(Debug, PartialEq)] pub struct EncryptedDataPayload<T, F>(T, F); impl<T: AsRef<[u8]>, F> DataHeader for EncryptedDataPayload<T, F> { fn as_data_bytes(&self) -> &[u8] { self.0.as_ref() } } impl<T: AsRef<[u8]>, F: CryptoFactory> EncryptedDataPayload<T, F> { /// Creates a new EncryptedDataPayload if the provided data is acceptable. /// /// # Argument /// /// * data - the bytes for the payload. /// * factory - the factory that shall be used to create object for crypto functions. pub fn new_with_factory<'a>(data: T, factory: F) -> Result<Self, &'a str> { if Self::can_build_from(data.as_ref()) { Ok(Self(data, factory)) } else { Err("can not build EncryptedDataPayload from the provided data") } } fn can_build_from(bytes: &[u8]) -> bool { let has_acceptable_len = bytes.len() >= 12 && // TODO: Bug related to possibly insufficient number of bytes fhdr_length(bytes[5]) <= bytes.len(); if !has_acceptable_len { return false; } match MHDR(bytes[0]).mtype() { MType::ConfirmedDataUp | MType::ConfirmedDataDown | MType::UnconfirmedDataUp | MType::UnconfirmedDataDown => { true } _ => { false } } } /// Verifies that the DataPayload has correct MIC. pub fn validate_mic(&self, key: &AES128, fcnt: u32) -> bool { self.mic() == self.calculate_mic(key, fcnt) } fn calculate_mic(&self, key: &AES128, fcnt: u32) -> MIC { let d = self.0.as_ref(); securityhelpers::calculate_data_mic(&d[..d.len() - 4], self.1.new_mac(key), fcnt) } } impl<T: AsRef<[u8]> + AsMut<[u8]>, F: CryptoFactory> EncryptedDataPayload<T, F> { /// Decrypts the EncryptedDataPayload payload. /// /// This method consumes the EncryptedDataPayload as it reuses the underlying memory. Please /// note that it does not verify the mic. /// /// If used on the application server side for application payload decryption, the nwk_skey can /// be None. If used on the network server side and the app_skey is not available, app_skey can /// be None when fport is 0. Failure to meet those constraints will result in an Err being /// returned. /// /// # Argument /// /// * nwk_skey - the Network Session key used to decrypt the mac commands in case the payload /// is transporting those. /// * app_skey - the Application Session key used to decrypt the application payload in case /// the payload is transporting that. /// * fcnt - the counter used to encrypt the payload. /// /// # Examples /// /// ``` /// let mut data = vec![0x40, 0x04, 0x03, 0x02, 0x01, 0x80, 0x01, 0x00, 0x01, /// 0xa6, 0x94, 0x64, 0x26, 0x15, 0xd6, 0xc3, 0xb5, 0x82]; /// let key = lorawan::keys::AES128([1; 16]); /// let enc_phy = lorawan::parser::EncryptedDataPayload::new(data).unwrap(); /// let dec_phy = enc_phy.decrypt(None, Some(&key), 1); /// ``` pub fn decrypt<'a, 'b>(mut self, nwk_skey: Option<&'a AES128>, app_skey: Option<&'a AES128>, fcnt: u32) -> Result<DecryptedDataPayload<T>, &'b str> { let fhdr_length = self.fhdr_length(); let fhdr = self.fhdr(); let full_fcnt = compute_fcnt(fcnt, fhdr.fcnt()); let key = if self.f_port().is_some() && self.f_port().unwrap() != 0{ app_skey } else { nwk_skey }; if key.is_none() { return Err("key needed to decrypt the frm data payload was None"); } let data = self.0.as_mut(); let len = data.len(); let start = 1 + fhdr_length + 1; let end = len - 4; if start < end { securityhelpers::encrypt_frm_data_payload( &mut data[..], start, end, full_fcnt, &self.1.new_enc(&key.unwrap()), ); } Ok(DecryptedDataPayload(self.0)) } /// Verifies the mic and decrypts the EncryptedDataPayload payload if mic matches. /// /// This is helper method that combines validate_mic and decrypt. In case the mic is fine, it /// consumes the EncryptedDataPayload and reuses the underlying memory to produce /// DecryptedDataPayload. If the mic does not match, it returns the original /// EncryptedDataPayload so that it can be tried against the keys of another device that shares /// the same dev_addr. For an example please see [decrypt](#method.decrypt). pub fn decrypt_if_mic_ok<'a>(self, nwk_skey: &'a AES128, app_skey: &'a AES128, fcnt: u32) -> Result<DecryptedDataPayload<T>, Self> { if !self.validate_mic(nwk_skey, fcnt) { Err(self) } else { Ok(self.decrypt(Some(nwk_skey), Some(app_skey), fcnt).unwrap()) } } } fn compute_fcnt(old_fcnt: u32, fcnt: u16) -> u32 { ((old_fcnt >> 16) << 16) ^ u32::from(fcnt) } /// DecryptedDataPayload represents a decrypted DataPayload. /// /// It can be built either directly through the [new](#method.new) or using the /// [EncryptedDataPayload.decrypt](struct.EncryptedDataPayload.html#method.decrypt) function. #[derive(Debug, PartialEq)] pub struct DecryptedDataPayload<T>(T); impl<T: AsRef<[u8]>> DataHeader for DecryptedDataPayload<T> { fn as_data_bytes(&self) -> &[u8] { self.0.as_ref() } } impl<T: AsRef<[u8]>> DecryptedDataPayload<T> { /// Returns FRMPayload that can represent either application payload or mac commands if fport /// is 0. pub fn frm_payload(&self) -> Result<FRMPayload, &str> { let data = self.as_data_bytes(); let len = data.len(); let fhdr_length = self.fhdr_length(); //we have more bytes than fhdr + fport if len < fhdr_length + 6 { Ok(FRMPayload::None) } else if self.f_port() != Some(0) { // the size guarantees the existance of f_port Ok(FRMPayload::Data(&data[(1 + fhdr_length + 1)..(len - 4)])) } else { Ok(FRMPayload::MACCommands(FRMMacCommands::new( &data[(1 + fhdr_length + 1)..(len - 4)], self.is_uplink(), ))) } } } /// Parses a payload as LoRaWAN physical payload. /// /// # Argument /// /// * bytes - the data from which the PhyPayload is to be built. /// /// # Examples /// /// ``` /// let mut data = vec![0x40, 0x04, 0x03, 0x02, 0x01, 0x80, 0x01, 0x00, 0x01, /// 0xa6, 0x94, 0x64, 0x26, 0x15, 0xd6, 0xc3, 0xb5, 0x82]; /// if let Ok(lorawan::parser::PhyPayload::Data(phy)) = lorawan::parser::parse(data) { /// println!("{:?}", phy); /// } else { /// panic!("failed to parse data payload"); /// } /// ``` #[cfg(feature = "default-crypto")] pub fn parse<'a, T: AsRef<[u8]> + AsMut<[u8]>>(data: T) -> Result<PhyPayload<T, DefaultFactory>, &'a str> { parse_with_factory(data, DefaultFactory) } /// Parses a payload as LoRaWAN physical payload. /// /// Check out [parse](fn.parse.html) if you do not need custom crypto factory. /// /// # Argument /// /// * bytes - the data from which the PhyPayload is to be built. /// * factory - the factory that shall be used to create object for crypto functions. pub fn parse_with_factory<'a, T, F>(data: T, factory: F) -> Result<PhyPayload<T, F>, &'a str> where T: AsRef<[u8]> + AsMut<[u8]>, F: CryptoFactory { let bytes = data.as_ref(); let len = bytes.len(); // the smallest payload is a data payload without fport and FRMPayload // which is 12 bytes long. if len < 12 { return Err("insufficient number of bytes"); } match MHDR(bytes[0]).mtype() { MType::JoinRequest => { Ok(PhyPayload::JoinRequest(JoinRequestPayload::new_with_factory(data, factory)?)) }, MType::JoinAccept => { Ok(PhyPayload::JoinAccept(JoinAcceptPayload::Encrypted( EncryptedJoinAcceptPayload::new_with_factory(data, factory)?))) }, MType::UnconfirmedDataUp | MType::ConfirmedDataUp | MType::UnconfirmedDataDown | MType::ConfirmedDataDown => { Ok(PhyPayload::Data(DataPayload::Encrypted( EncryptedDataPayload::new_with_factory(data, factory)?))) }, _ => Err("unsupported message type") } } /// MHDR represents LoRaWAN MHDR. #[derive(Debug, PartialEq)] pub struct MHDR(u8); impl MHDR { pub fn new(byte: u8) -> MHDR { MHDR(byte) } /// Gives the type of message that PhyPayload is carrying. pub fn mtype(&self) -> MType { match self.0 >> 5 { 0 => MType::JoinRequest, 1 => MType::JoinAccept, 2 => MType::UnconfirmedDataUp, 3 => MType::UnconfirmedDataDown, 4 => MType::ConfirmedDataUp, 5 => MType::ConfirmedDataDown, 6 => MType::RFU, _ => MType::Proprietary, } } /// Gives the version of LoRaWAN payload format. pub fn major(&self) -> Major { if self.0.trailing_zeros() >= 2 { Major::LoRaWANR1 } else { Major::RFU } } } impl From<u8> for MHDR { fn from(v: u8) -> Self { MHDR(v) } } /// MType gives the possible message types of the PhyPayload. #[derive(Debug, PartialEq)] pub enum MType { JoinRequest, JoinAccept, UnconfirmedDataUp, UnconfirmedDataDown, ConfirmedDataUp, ConfirmedDataDown, RFU, Proprietary, } /// Major gives the supported LoRaWAN payload formats. #[derive(Debug, PartialEq)] pub enum Major { LoRaWANR1, RFU, } fixed_len_struct! { /// EUI64 represents a 64 bit EUI. struct EUI64[8]; } fixed_len_struct! { /// DevNonce represents a 16 bit device nonce. struct DevNonce[2]; } fixed_len_struct! { /// AppNonce represents a 24 bit network server nonce. struct AppNonce[3]; } fixed_len_struct! { /// DevAddr represents a 32 bit device address. struct DevAddr[4]; } impl<T: AsRef<[u8]>> DevAddr<T> { pub fn nwk_id(&self) -> u8 { self.0.as_ref()[0] >> 1 } } fixed_len_struct! { /// NwkAddr represents a 24 bit network address. struct NwkAddr[3]; } /// FHDR represents FHDR from DataPayload. #[derive(Debug, PartialEq)] pub struct FHDR<'a>(&'a [u8], bool); impl<'a> FHDR<'a> { pub fn new_from_raw(bytes: &'a [u8], uplink: bool) -> FHDR { FHDR(bytes, uplink) } pub fn new(bytes: &'a [u8], uplink: bool) -> Option<FHDR> { let data_len = bytes.len(); if data_len < 7 { return None; } if data_len < fhdr_length(bytes[4]) { return None; } Some(FHDR(bytes, uplink)) } /// Gives the device address associated with the given payload. pub fn dev_addr(&self) -> DevAddr<&'a [u8]> { DevAddr::new_from_raw(&self.0[0..4]) } /// Gives the FCtrl associated with the given payload. pub fn fctrl(&self) -> FCtrl { FCtrl(self.0[4], self.1) } /// Gives the truncated FCnt associated with the given payload. pub fn fcnt(&self) -> u16 { (u16::from(self.0[6]) << 8) | u16::from(self.0[5]) } /// Gives the piggy-backed MAC ommands associated with the given payload. pub fn fopts(&self) -> MacCommandIterator { let f_opts_len = FCtrl(self.0[4], self.1).f_opts_len(); parse_mac_commands(&self.0[7 as usize..(7 + f_opts_len) as usize], self.1) } } /// FCtrl represents the FCtrl from FHDR. #[derive(Debug, PartialEq)] pub struct FCtrl(u8, bool); impl FCtrl { pub fn new(bytes: u8, uplink: bool) -> FCtrl { FCtrl(bytes, uplink) } /// Gives whether ADR is enabled or not. pub fn adr(&self) -> bool { self.0 >> 7 == 1 } /// Gives whether ADR ACK is requested. pub fn adr_ack_req(&self) -> bool { self.1 && self.0 & (1 << 6) != 0 } /// Gives whether ack bit is set. pub fn ack(&self) -> bool { self.0 & (1 << 5) != 0 } /// Gives whether there are more payloads pending. pub fn f_pending(&self) -> bool { !self.1 && self.0 & (1 << 4) != 0 } /// Gives the size of FOpts. pub fn f_opts_len(&self) -> u8 { self.0 & 0x0f } /// Gives the binary representation of the FCtrl. pub fn raw_value(&self) -> u8 { self.0 } } /// FRMPayload represents the FRMPayload that can either be the application /// data or mac commands. #[derive(Debug, PartialEq)] pub enum FRMPayload<'a> { Data(&'a [u8]), MACCommands(FRMMacCommands<'a>), None, } /// FRMMacCommands represents the mac commands. #[derive(Debug, PartialEq)] pub struct FRMMacCommands<'a>(bool, &'a [u8]); impl<'a> FRMMacCommands<'a> { pub fn new(bytes: &'a [u8], uplink: bool) -> Self { FRMMacCommands(uplink, bytes) } /// Gives the list of mac commands represented in the FRMPayload. pub fn mac_commands(&self) -> MacCommandIterator { parse_mac_commands(self.1, self.0) } }