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2 Commits

Author SHA1 Message Date
kirbylife 4396e6a43d Reduce the bin size removing the sha1_smol library 2023-04-26 23:33:28 -06:00
kirbylife dbc75352ac Finally works! 2023-04-26 21:50:18 -06:00
10 changed files with 669 additions and 196 deletions

50
Cargo.lock generated
View File

@ -5,7 +5,7 @@ version = 3
[[package]]
name = "arduino-hal"
version = "0.1.0"
source = "git+https://github.com/rahix/avr-hal#fb609ab0d14c5a0a44e2dff3e5e514cb612a529a"
source = "git+https://github.com/rahix/avr-hal#e29a7be5b1fa9d490ded11e539d345af041ccef6"
dependencies = [
"atmega-hal",
"avr-device",
@ -19,7 +19,7 @@ dependencies = [
[[package]]
name = "atmega-hal"
version = "0.1.0"
source = "git+https://github.com/rahix/avr-hal#fb609ab0d14c5a0a44e2dff3e5e514cb612a529a"
source = "git+https://github.com/rahix/avr-hal#e29a7be5b1fa9d490ded11e539d345af041ccef6"
dependencies = [
"avr-device",
"avr-hal-generic",
@ -33,9 +33,9 @@ checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
[[package]]
name = "avr-device"
version = "0.5.0"
version = "0.5.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "deb45711b7227cb3f799c40c4e0e8beea1765acff8d06a14bb3479c1a549d8b0"
checksum = "644690f9699830f0efce38ca9d41c7ad51a6ec1829364dd272638938c953673a"
dependencies = [
"avr-device-macros",
"bare-metal",
@ -45,9 +45,9 @@ dependencies = [
[[package]]
name = "avr-device-macros"
version = "0.5.0"
version = "0.5.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "87c428a2384981d8460668c48c766ff18e7e91d2d467f7b103151984ee952d38"
checksum = "ba8b49941a5148cec432d5180d205871f0132f9f15b7225a9f3ad9e2bae026cb"
dependencies = [
"proc-macro2",
"quote",
@ -57,7 +57,7 @@ dependencies = [
[[package]]
name = "avr-hal-generic"
version = "0.1.0"
source = "git+https://github.com/rahix/avr-hal#fb609ab0d14c5a0a44e2dff3e5e514cb612a529a"
source = "git+https://github.com/rahix/avr-hal#e29a7be5b1fa9d490ded11e539d345af041ccef6"
dependencies = [
"avr-device",
"cfg-if 0.1.10",
@ -76,12 +76,6 @@ version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f8fe8f5a8a398345e52358e18ff07cc17a568fbca5c6f73873d3a62056309603"
[[package]]
name = "binascii"
version = "0.1.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "383d29d513d8764dcdc42ea295d979eb99c3c9f00607b3692cf68a431f7dca72"
[[package]]
name = "cfg-if"
version = "0.1.10"
@ -107,8 +101,7 @@ dependencies = [
[[package]]
name = "ds323x"
version = "0.5.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "057e63d03a3beb83d3c9b7a19b799c60e203b0c53f1bbec6a715804907f73a2b"
source = "git+https://github.com/kirbylife/ds323x-rs?branch=fix-set-day-format#e204b77494f921cfc276c9a66e6e9ba95dc4e142"
dependencies = [
"embedded-hal",
"rtcc",
@ -130,6 +123,11 @@ version = "0.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "723dce4e9f25b6e6c5f35628e144794e5b459216ed7da97b7c4b66cdb3fa82ca"
[[package]]
name = "hmac-sha1-compact"
version = "1.1.3"
source = "git+https://github.com/kirbylife/rust-hmac-sha1#a3c4116837efb8a850fb0d03985831ce4dc2bc12"
[[package]]
name = "nb"
version = "0.1.3"
@ -184,9 +182,9 @@ checksum = "dc375e1527247fe1a97d8b7156678dfe7c1af2fc075c9a4db3690ecd2a148068"
[[package]]
name = "proc-macro2"
version = "1.0.54"
version = "1.0.56"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e472a104799c74b514a57226160104aa483546de37e839ec50e3c2e41dd87534"
checksum = "2b63bdb0cd06f1f4dedf69b254734f9b45af66e4a031e42a7480257d9898b435"
dependencies = [
"unicode-ident",
]
@ -200,6 +198,12 @@ dependencies = [
"proc-macro2",
]
[[package]]
name = "randomize"
version = "3.0.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "88c38c99b51f33c9fcc655252bf02ac8048eb70f35244e4697b0de9c473e940a"
[[package]]
name = "rtcc"
version = "0.3.0"
@ -220,19 +224,15 @@ name = "rustytoken"
version = "0.1.0"
dependencies = [
"arduino-hal",
"binascii",
"ds323x",
"embedded-hal",
"hmac-sha1-compact",
"nb 1.1.0",
"panic-halt",
"sha1_smol",
"randomize",
"ufmt 0.2.0",
]
[[package]]
name = "sha1_smol"
version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
[[package]]
name = "syn"
version = "1.0.109"

View File

@ -5,16 +5,17 @@ edition = "2021"
[dependencies]
arduino-hal = { git = "https://github.com/rahix/avr-hal", features = ["arduino-uno"] }
ds323x = { git = "https://github.com/kirbylife/ds323x-rs", branch = "fix-set-day-format" }
hmac-sha1-compact = { git = "https://github.com/kirbylife/rust-hmac-sha1" }
panic-halt = "0.2.0"
sha1_smol = "1.0.0"
binascii = { version = "0.1", default-features = false, features = ["decode"] }
ds323x = "0.5.0"
ufmt = "0.2.0"
embedded-hal = "0.2.7"
nb = "1.1.0"
randomize = "3.0.1"
ufmt = "0.2.0"
[profile.release]
lto = true
panic = "abort"
strip = true
opt-level = "z"
opt-level = "s"
codegen-units = 1

63
src/button.rs 100644
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@ -0,0 +1,63 @@
use embedded_hal::digital::v2::InputPin;
pub struct Button<'a, P> {
pin: &'a P,
state: bool,
is_pullup: bool,
}
#[derive(PartialEq)]
pub enum Event {
PressDown,
PressUp,
Pressed,
None,
}
impl<'a, P: InputPin> Button<'a, P> {
pub fn new(pin: &'a P, is_pullup: bool) -> Self {
let mut state = pin.is_high().map_err(|_| ()).unwrap();
if is_pullup {
state = !state;
}
Button {
pin,
state,
is_pullup,
}
}
fn read_pin(&self) -> bool {
let mut inc = 0;
for _ in 0..100 {
let mut state = self.pin.is_high().map_err(|_| ()).unwrap();
if self.is_pullup {
state = !state;
}
if state {
inc += 1;
}
}
inc > 70
}
pub fn update(&mut self) -> Event {
let actual_state = self.read_pin();
match (self.state, actual_state) {
(false, false) => Event::None,
(true, false) => {
self.state = !self.state;
Event::PressUp
}
(false, true) => {
self.state = !self.state;
Event::PressDown
}
(true, true) => Event::Pressed,
}
}
}

View File

@ -1,40 +1,16 @@
use sha1_smol::Sha1;
use hmac_sha1_compact::HMAC;
const BLOCK_SIZE: usize = 64;
pub const INTERVAL: u64 = 30;
pub fn hmac_sha1(key: &[u8], message: &[u8], output: &mut [u8]) {
// Preprocess the key.
let mut key_padded = [0u8; BLOCK_SIZE];
if key.len() > BLOCK_SIZE {
let mut hash = Sha1::new();
hash.update(key);
let key_digest = hash.digest().bytes();
key_padded[..20].copy_from_slice(&key_digest);
} else {
key_padded[..key.len()].copy_from_slice(key);
}
for byte in &mut key_padded {
*byte ^= 0x36;
}
pub fn generate_otp_token(private_key: &[u8], actual_time: u64) -> u32 {
let interval = actual_time / INTERVAL;
let msg = interval.to_be_bytes();
// Hash the inner padded key and the message.
let mut hash = Sha1::new();
hash.update(&key_padded[..]);
hash.update(message);
let mut inner_hash = [0u8; 20];
inner_hash.copy_from_slice(&hash.digest().bytes());
let hmac_digest = HMAC::mac(&msg, private_key);
// Preprocess the key again.
for byte in &mut key_padded {
*byte ^= 0x36 ^ 0x5c;
}
let start = (hmac_digest[19] & 0xF) as usize;
let bytes: [u8; 4] = hmac_digest[start..start + 4].try_into().unwrap();
// Hash the outer padded key and the inner hash.
let mut hash = Sha1::new();
hash.update(&key_padded[..]);
hash.update(&inner_hash[..]);
let hmac_digest = hash.digest().bytes();
// Copy the result into the output buffer.
output.copy_from_slice(&hmac_digest);
let raw_token = u32::from_be_bytes(bytes);
((raw_token & 0x7F_FF_FF_FF) % 1_000_000) as u32
}

View File

@ -11,17 +11,9 @@ pub struct Datetime {
impl Datetime {
pub fn unix_epoch(&self) -> u64 {
let mut year: i64 = self.year as i64 - 1900;
let mut month: i64 = self.month as i64 - 1;
if month >= 12 || month < 0 {
let mut adj = month / 12;
month %= 12;
if month < 0 {
adj -= 1;
month += 12;
}
year += adj as i64;
}
let year: i64 = self.year as i64 - 1900;
let month: i64 = self.month as i64 - 1;
let (mut t, is_leap) = year_to_secs(year);
t += month_to_secs(month, is_leap);
t += 86400 * (self.day as i64 - 1);
@ -35,21 +27,21 @@ impl Datetime {
let year = rtc.year().map_err(|_| ()).unwrap();
let month = rtc.month().map_err(|_| ()).unwrap();
let day = rtc.day().map_err(|_| ()).unwrap();
let hour = match rtc.hours().map_err(|_| ()).unwrap() {
let hours = match rtc.hours().map_err(|_| ()).unwrap() {
ds323x::Hours::AM(val) => val,
ds323x::Hours::PM(val) => val + 12,
ds323x::Hours::H24(val) => val,
};
let minute = rtc.minutes().map_err(|_| ()).unwrap();
let second = rtc.seconds().map_err(|_| ()).unwrap();
let minutes = rtc.minutes().map_err(|_| ()).unwrap();
let seconds = rtc.seconds().map_err(|_| ()).unwrap();
Datetime {
year: year,
month: month,
day: day,
hours: hour,
minutes: minute,
seconds: second,
year,
month,
day,
hours,
minutes,
seconds,
}
}
}
@ -58,64 +50,52 @@ fn year_to_secs(year: i64) -> (i64, bool) {
let is_leap: bool;
let res: i64;
if year - 2 <= 136 {
let y = year as i32;
let mut leaps = (y - 68) >> 2;
if !((y - 68) & 3 != 0) {
leaps -= 1;
is_leap = true;
} else {
is_leap = false;
}
res = 31536000 * (y - 70) as i64 + 86400 * leaps as i64;
} else {
let mut cycles: i64;
let centuries: i64;
let mut leaps: i64;
let mut rem: i64;
let mut cycles: i64;
let centuries: i64;
let mut leaps: i64;
let mut rem: i64;
cycles = (year - 100) / 400;
rem = (year - 100) % 400;
if rem < 0 {
cycles -= 1;
rem += 400;
cycles = (year - 100) / 400;
rem = (year - 100) % 400;
if rem < 0 {
cycles -= 1;
rem += 400;
}
if rem == 0 {
is_leap = true;
centuries = 0;
leaps = 0;
} else {
if rem >= 200 {
if rem >= 300 {
centuries = 3;
rem -= 300;
} else {
centuries = 2;
rem -= 200;
}
} else {
if rem >= 100 {
centuries = 1;
rem -= 100;
} else {
centuries = 0;
}
}
if rem == 0 {
is_leap = true;
centuries = 0;
is_leap = false;
leaps = 0;
} else {
if rem >= 200 {
if rem >= 300 {
centuries = 3;
rem -= 300;
} else {
centuries = 2;
rem -= 200;
}
} else {
if rem >= 100 {
centuries = 1;
rem -= 100;
} else {
centuries = 0;
}
}
if rem == 0 {
is_leap = false;
leaps = 0;
} else {
leaps = rem / 4;
rem %= 4;
is_leap = rem == 0;
}
leaps = rem / 4;
rem %= 4;
is_leap = rem == 0;
}
leaps += 97 * cycles + 24 * centuries - (is_leap as i64);
res = (year - 100) * 31536000 + leaps * 86400 + 946684800 + 86400;
}
leaps += 97 * cycles + 24 * centuries - (is_leap as i64);
res = (year - 100) * 31536000 + leaps * 86400 + 946684800 + 86400;
(res, is_leap)
}

View File

@ -1,60 +1,34 @@
#![no_std]
#![no_main]
mod button;
mod crypto;
mod datetime;
mod screen;
mod storage;
use arduino_hal::default_serial;
use arduino_hal::delay_ms;
use crypto::hmac_sha1;
// use arduino_hal::delay_ms;
use arduino_hal::prelude::*;
use crypto::generate_otp_token;
use crypto::INTERVAL;
use ds323x::Rtcc;
use nb::block;
use panic_halt as _;
use storage::SECRET_KEY_MAX_LEN;
use storage::SECRET_KEY_NAME_LEN;
const INTERVAL: u64 = 30;
const SECRET_KEY_MAX_LEN: usize = 32;
fn process_secret<'a>(secret: &str, output: &mut [u8]) -> usize {
// RFC 6238 Doesn't specify a max length for the secret keys, So I chose 32
// You can change the max length by modifying the const
let mut result = [0u8; SECRET_KEY_MAX_LEN];
let mut inc = 0;
let offset = match 8 - (secret.len() % 8) {
8 => 0,
n => n,
};
for c in secret.chars() {
result[inc] = c.to_ascii_uppercase() as u8;
inc += 1;
}
for _ in 0..offset {
result[inc] = '=' as u8;
inc += 1;
}
let decoded = match binascii::b32decode(&result[..inc], output).ok() {
Some(bytes) => bytes,
None => "".as_bytes(), // TODO: Implement a way to display errors
};
decoded.len()
}
fn generate_otp_token(private_key: &str, actual_time: u64) -> u32 {
let mut output = [0u8; 32];
let private_key_len = process_secret(private_key, &mut output);
let interval = actual_time / INTERVAL;
let msg = interval.to_be_bytes();
let mut hmac_digest = [0u8; 20];
hmac_sha1(&output[..private_key_len], &msg, &mut hmac_digest);
let start = (hmac_digest[19] & 0xF) as usize;
let bytes: [u8; 4] = hmac_digest[start..start + 4].try_into().unwrap();
let raw_token = u32::from_be_bytes(bytes);
((raw_token & 0x7F_FF_FF_FF) % 1_000_000) as u32
}
const ENDL: u8 = 0;
const OK: u8 = 1;
const ERROR: u8 = 2;
const HANDSHAKE: u8 = 3;
const SET_TIMESTAMP: u8 = 10;
const ADD_TOKEN: u8 = 20;
const DELETE_TOKEN: u8 = 30;
const GET_TOKENS: u8 = 40;
const WIPE_TOKENS: u8 = 50;
const EXIT: u8 = 254;
#[arduino_hal::entry]
fn main() -> ! {
@ -72,21 +46,159 @@ fn main() -> ! {
);
let mut rtc = ds323x::Ds323x::new_ds3231(i2c_clock);
let mut rs = pins.d12.into_output();
let mut en = pins.d11.into_output();
let mut d4 = pins.d5.into_output();
let mut d5 = pins.d4.into_output();
let mut d6 = pins.d3.into_output();
let mut d7 = pins.d2.into_output();
let mut display = screen::StnScreen::new(&mut rs, &mut en, &mut d4, &mut d5, &mut d6, &mut d7);
display.clear();
let datetime = datetime::Datetime::from_ds3231(&mut rtc);
let timestamp = datetime.unix_epoch();
ufmt::uwriteln!(&mut serial, "Timestamp: {}", timestamp).unwrap();
let mut eeprom = arduino_hal::Eeprom::new(dp.EEPROM);
let mut tokens = storage::Tokens::new(&mut eeprom, datetime.unix_epoch());
let token = generate_otp_token("FS7J22EHLLSOGKUVJKV2XE7FTIX24JAJ", 1680155315);
ufmt::uwriteln!(&mut serial, "token: {}", token).unwrap();
let up = pins.d6.into_pull_up_input();
let mut button = button::Button::new(&up, true);
delay_ms(5000);
let token = generate_otp_token("FS7J22EHLLSOGKUVJKV2XE7FTIX24JAJ", 1680155315);
ufmt::uwriteln!(&mut serial, "token: {}", token).unwrap();
button.update();
if button.update() == button::Event::Pressed {
display.write_str("Connected to");
display.set_cursor(0, 1);
display.write_str("USB...");
loop {
// Waiting from a command since the tool
let cmd = block!(serial.read()).unwrap_or(u8::MAX);
display.set_cursor(8, 1);
display.write_str("---");
display.set_cursor(8, 1);
display.write_u32(cmd as u32);
delay_ms(5000);
let token = generate_otp_token("FS7J22EHLLSOGKUVJKV2XE7FTIX24JAJ", 1680155315);
ufmt::uwriteln!(&mut serial, "token: {}", token).unwrap();
match cmd {
EXIT => {}
HANDSHAKE => serial.write(OK).unwrap(),
SET_TIMESTAMP => {
serial.write(OK).unwrap();
let year = loop {
let y = block!(serial.read()).unwrap();
serial.write(y).unwrap();
if block!(serial.read()).unwrap() == OK {
break y;
}
};
let month = loop {
let m = block!(serial.read()).unwrap();
serial.write(m).unwrap();
if block!(serial.read()).unwrap() == OK {
break m;
}
};
let day = loop {
let d = block!(serial.read()).unwrap();
serial.write(d).unwrap();
if block!(serial.read()).unwrap() == OK {
break d;
}
};
let hours = loop {
let h = block!(serial.read()).unwrap();
serial.write(h).unwrap();
if block!(serial.read()).unwrap() == OK {
break h;
}
};
let minutes = loop {
let m = block!(serial.read()).unwrap();
serial.write(m).unwrap();
if block!(serial.read()).unwrap() == OK {
break m;
}
};
let seconds = loop {
let s = block!(serial.read()).unwrap();
serial.write(s).unwrap();
if block!(serial.read()).unwrap() == OK {
break s;
}
};
rtc.set_year(year as u16 + 2000).unwrap();
rtc.set_month(month).unwrap();
rtc.set_day(day).unwrap();
rtc.set_hours(ds323x::Hours::H24(hours)).unwrap();
rtc.set_minutes(minutes).unwrap();
rtc.set_seconds(seconds).unwrap();
serial.write(OK).unwrap();
}
ADD_TOKEN => match tokens.search_free() {
Some(index) => {
serial.write(OK).unwrap();
let mut name_buff = [0u8; SECRET_KEY_NAME_LEN as usize];
for i in 0..name_buff.len() {
let ch = block!(serial.read()).unwrap();
if ch == ENDL {
break;
} else {
name_buff[i] = ch;
}
}
let mut key_buff = [0u8; SECRET_KEY_MAX_LEN as usize];
for i in 0..key_buff.len() {
let ch = block!(serial.read()).unwrap();
if ch == ENDL {
break;
} else {
key_buff[i] = ch;
}
}
match tokens.write(index, &name_buff, &key_buff) {
Some(_) => serial.write(OK).unwrap(),
None => serial.write(ERROR).unwrap(),
}
}
None => serial.write(ERROR).unwrap(),
},
WIPE_TOKENS => {
serial.write(OK).unwrap();
tokens.wipe_all_tokens();
serial.write(OK).unwrap();
}
_ => {}
}
}
}
match tokens.current {
Some(index) => {
let mut buff_name = [0u8; SECRET_KEY_NAME_LEN as usize];
let mut buff_key = [0u8; SECRET_KEY_MAX_LEN as usize];
match tokens.read(index, &mut buff_name, &mut buff_key) {
Some((len_name, len_key)) => {
let name = core::str::from_utf8(&buff_name[..len_name]).unwrap();
let key = &buff_key[..len_key];
let dt = datetime::Datetime::from_ds3231(&mut rtc);
let timestamp = dt.unix_epoch();
let token = generate_otp_token(key, timestamp);
display.set_cursor(0, 0);
display.write_str(name);
display.set_cursor(0, 1);
display.write_u32(token);
}
_ => {
// display.clear();
// display.set_cursor(0, 0);
// display.write_str("ERROR");
}
}
}
_ => {}
}
loop {
led.toggle();

View File

@ -2,11 +2,23 @@ use arduino_hal::delay_ms;
use arduino_hal::delay_us;
use embedded_hal::digital::v2::OutputPin;
// The CMDs codes are documented here:
// https://www.openhacks.com/uploadsproductos/eone-1602a1.pdf
const INIT_CMD: u8 = 0x03; // 0b00000011
const MODE_4_BITS_CMD: u8 = 0x02; // 0b00000010
const DISPLAY_MODE_CMD: u8 = 0x28; // 0b00101000
const DISPLAY_MODE_16X2_CMD: u8 = 0x28; // 0b00101000
const ENABLE_SCREEN_CMD: u8 = 0x0C; // 0b00001100
const CLEAN_SCREEN_CMD: u8 = 0x01; // 0b00000001
const SHIFT_LEFT_CMD: u8 = 0x10; // 0b10000
const SHIFT_RIGHT_CMD: u8 = 0x14; // 0b10100
const MOVE_CURSOR_CMD: u8 = 0x80; // 0b10000000
const ROW_OFFSETS: [u8; 2] = [0x00, 0x40];
pub enum Direction {
Left = SHIFT_LEFT_CMD as isize,
Right = SHIFT_RIGHT_CMD as isize,
}
pub struct StnScreen<'a, RS, EN, D4, D5, D6, D7> {
rs: &'a mut RS,
@ -55,8 +67,9 @@ impl<
delay_us(100);
display.write_nibble(MODE_4_BITS_CMD, false);
delay_us(100);
display.send_cmd(DISPLAY_MODE_CMD, false);
display.send_cmd(DISPLAY_MODE_16X2_CMD, false);
display.send_cmd(ENABLE_SCREEN_CMD, false);
display.clear();
display
}
@ -85,8 +98,19 @@ impl<
self.pulse_enable();
}
fn clear(&mut self) {
display.send_cmd(CLEAN_SCREEN_CMD, false);
pub fn clear(&mut self) {
self.send_cmd(CLEAN_SCREEN_CMD, false);
}
pub fn shift(&mut self, dir: Direction) {
let cmd = dir as u8;
self.send_cmd(cmd, false);
}
pub fn set_cursor(&mut self, col: u8, row: u8) {
let row_offset = ROW_OFFSETS[row as usize];
let address_position = row_offset | col;
self.send_cmd(MOVE_CURSOR_CMD | address_position, false);
}
pub fn write_char(&mut self, c: char) {
@ -102,8 +126,36 @@ impl<
self.write_char(c);
}
}
pub fn write_u32(&mut self, num: u32) {
// The max number in an u32 is: 4,294,967,295
let mut buff = [0; 10];
let len = num_chars(num, &mut buff);
self.write_str(&core::str::from_utf8(&buff[..len]).unwrap());
}
}
fn last_bit(n: u8) -> bool {
(n & 1) != 0
}
fn num_rev(mut num: u32) -> u32 {
let mut rev_num = 0;
while num > 0 {
let digit = num % 10;
rev_num = rev_num * 10 + digit;
num /= 10;
}
rev_num
}
fn num_chars(n: u32, output: &mut [u8]) -> usize {
let mut n = num_rev(n);
let mut i = 0;
while n > 0 {
output[i] = (n % 10) as u8 + '0' as u8;
n = n / 10;
i += 1;
}
i
}

131
src/storage.rs 100644
View File

@ -0,0 +1,131 @@
use arduino_hal::eeprom::Eeprom;
use randomize::PCG32;
pub const SECRET_KEY_MAX_LEN: u16 = 32;
pub const SECRET_KEY_NAME_LEN: u16 = 16;
pub const SECRET_KEY_FULL_LEN: u16 = SECRET_KEY_MAX_LEN + SECRET_KEY_NAME_LEN;
pub struct Tokens<'a> {
mem: &'a mut Eeprom,
pub current: Option<u16>,
capacity: u16,
rand: PCG32,
}
impl<'a> Tokens<'a> {
pub fn new(mem: &'a mut Eeprom, rand_seed: u64) -> Self {
let capacity = mem.capacity() / SECRET_KEY_FULL_LEN;
let mut tokens = Tokens {
mem,
capacity,
rand: PCG32::seed(rand_seed, 1),
current: None,
};
tokens.current = tokens.first();
tokens
}
pub fn search_free(&self) -> Option<u16> {
for n in 0..self.capacity {
let index = SECRET_KEY_FULL_LEN * n;
if self.mem.read_byte(index) == 255 {
return Some(n);
}
}
None
}
fn first(&self) -> Option<u16> {
for n in 0..self.capacity {
let index = SECRET_KEY_FULL_LEN * n;
if self.mem.read_byte(index) != 255 {
return Some(n);
}
}
return None;
}
pub fn next(&mut self) -> Option<u16> {
let mut index = self.current.unwrap();
for _ in 0..self.capacity {
index = (index + 1) % self.capacity;
if self.mem.read_byte(index * SECRET_KEY_FULL_LEN) != 255 {
self.current = Some(index);
return Some(index);
}
}
None
}
pub fn prev(&mut self) -> Option<u16> {
todo!();
}
pub fn read(&self, index: u16, name: &mut [u8], key: &mut [u8]) -> Option<(usize, usize)> {
name.fill(0);
key.fill(0);
let index_name = index * SECRET_KEY_FULL_LEN;
let index_key = (index * SECRET_KEY_FULL_LEN) + SECRET_KEY_NAME_LEN;
match self.mem.read(index_name, name) {
Ok(_) => {}
Err(_) => return None,
}
match self.mem.read(index_key, key) {
Ok(_) => {}
Err(_) => return None,
}
let len_name = name
.iter()
.position(|&n| n == 0)
.unwrap_or(SECRET_KEY_NAME_LEN as usize);
let len_key = key
.iter()
.position(|&n| n == 0)
.unwrap_or(SECRET_KEY_MAX_LEN as usize);
Some((len_name, len_key))
}
pub fn write(&mut self, index: u16, name: &[u8], key: &[u8]) -> Option<u16> {
let index_name = index * SECRET_KEY_FULL_LEN;
let index_key = (index * SECRET_KEY_FULL_LEN) + SECRET_KEY_NAME_LEN;
match self.mem.write(index_name, name) {
Ok(_) => {}
Err(_) => return None,
}
match self.mem.write(index_key, key) {
Ok(_) => {}
Err(_) => return None,
}
Some(index)
}
pub fn delete(&mut self, index: u16) -> Option<u16> {
// The Arduino's EEPROM memory has a maximum number of write cycles.
// To keep writes to a minimum, only the first byte of the token name is set to 0
// and a byte of the key is randomly chosen to be overwritten with
// another random value, so that it's unrecoverable.
let index_name = index * SECRET_KEY_FULL_LEN;
let index_key = (index * SECRET_KEY_FULL_LEN) + SECRET_KEY_NAME_LEN;
let index_key = index_key + (self.rand.next_u32() % SECRET_KEY_MAX_LEN as u32) as u16;
let rand_byte = (self.rand.next_u32() % 255) as u8;
self.mem.write_byte(index_name, 255);
self.mem.write_byte(index_key, rand_byte);
Some(index)
}
pub fn wipe_all_tokens(&mut self) -> u8 {
let mut inc = 0;
for n in 0..self.capacity {
let index = SECRET_KEY_FULL_LEN * n;
if self.mem.read_byte(index) != 255 {
self.delete(index);
inc += 1;
}
}
inc
}
}

157
tools/menu.py 100644
View File

@ -0,0 +1,157 @@
from datetime import datetime
from time import sleep
from typing import Any
import base64
import serial
import sys
ENDL = bytes([0])
OK = bytes([1])
ERROR = bytes([2])
HANDSHAKE = bytes([3])
SET_TIMESTAMP = bytes([10])
ADD_TOKEN = bytes([20])
DELETE_TOKEN = bytes([30])
GET_TOKENS = bytes([40])
WIPE_TOKENS = bytes([50])
EXIT = bytes([254])
def loop_input(msg: str, valid_values: Any) -> str:
valid_values = list(map(str, valid_values))
while True:
data = input(msg)
if data not in valid_values:
print(f"'{data}' isn't a valid value, please enter a value in {valid_values}")
else:
break
return data
def b(n: int) -> bytes:
return bytes([n])
def process_secret(secret: str) -> bytes:
offset = 8 - (len(secret) % 8)
if offset != 8:
secret += "=" * offset
return base64.b32decode(secret, casefold=True)
def send_and_validate(value: bytes, conn):
while True:
print(f"Send {list(value)}")
conn.write(value)
resp = conn.read()
print(f"Received {list(resp)}")
if resp == value:
conn.write(OK)
break
else:
conn.write(ERROR)
def get_datetime_items() -> dict[str, bytes]:
now = datetime.utcnow()
return {
"year": b(now.year - 2000),
"month": b(now.month),
"day": b(now.day),
"hours": b(now.hour),
"minutes": b(now.minute),
"seconds": b(now.second)
}
def main(argv: list[str]):
port = argv[-1]
conn = serial.Serial(port=port, baudrate=9600)
print("UP + Reset to enable the USB connection")
input("Press Enter if the device in the USB mode...")
conn.write(HANDSHAKE)
sleep(0.1)
res = conn.read()
if res != OK:
print("A handshake could not be performed")
print("Check the connection with your Arduino")
return 1
else:
print("Handshake successfully performed")
while True:
print("What do you want to do?")
print("1) Update timestamp")
print("2) Add a new token")
print("3) Remove a token")
print("4) WIPE ALL THE TOKENS")
print("5) EXIT")
opt = loop_input(">>> ", range(1, 6))
# Update Timestamp
if opt == "1":
conn.write(SET_TIMESTAMP)
sleep(0.1)
resp = conn.read()
sleep(0.1)
if resp == ERROR:
print(f"Error in the communication: Error {resp}")
continue
date_items = get_datetime_items();
send_and_validate(date_items["year"], conn)
send_and_validate(date_items["month"], conn)
send_and_validate(date_items["day"], conn)
send_and_validate(date_items["hours"], conn)
send_and_validate(date_items["minutes"], conn)
send_and_validate(date_items["seconds"], conn)
resp = conn.read()
if resp != OK:
print(f"Error in the communication: Error {resp}")
else:
print("Timestamp updated successfully!")
# Add token
elif opt == "2":
conn.write(ADD_TOKEN)
sleep(0.1)
resp = conn.read()
if resp == ERROR:
print("The memory of the device is full")
continue
name = input("Enter the name of the new token (16 chars max):\n>>> ")
name = name.strip()[:16].encode("ascii")
key = input("Enter the OTP secret key (32 chars max):\n>>> ")
key = process_secret(key.strip()[:32])
for ch in name:
conn.write(b(ch))
conn.write(ENDL)
for ch in key:
conn.write(b(ch))
conn.write(ENDL)
resp = conn.read()
if resp == ERROR:
print("Error trying to add the token, try again")
else:
print("Token added successfully!")
# Wipe tokens
elif opt == "4":
conn.write(WIPE_TOKENS)
sleep(0.1)
_ = conn.read()
resp = conn.read()
if resp == OK:
print("All the tokens wipped successfully!")
elif opt == "5":
return 0
if __name__ == "__main__":
attrs = sys.argv
if len(attrs) == 1:
print("You need to specify the Arduino's serial port")
print("Example:")
print(f"python {attrs[0]} /dev/ttyUSB0")
sys.exit(1)
sys.exit(main(attrs[1:]))

View File

@ -1 +1,2 @@
avrdude -p atmega328p -c arduino -P /dev/ttyACM0 -U flash:w:target/avr-atmega328p/release/rustytoken.elf:e
# avrdude -p atmega328p -c arduino -P /dev/ttyACM0 -U flash:w:target/avr-atmega328p/release/rustytoken.elf:e
avrdude -p atmega328p -c arduino -P /dev/ttyUSB0 -U flash:w:target/avr-atmega328p/release/rustytoken.elf:e