From c7f405edf5773e29e58d3a218de2a81d5415d63d Mon Sep 17 00:00:00 2001 From: Sergi Delgado Segura Date: Mon, 22 Mar 2021 11:14:25 +0100 Subject: [PATCH] Adds zbase32 encoding --- lightning/src/util/mod.rs | 1 + lightning/src/util/zbase32.rs | 137 ++++++++++++++++++++++++++++++++++ 2 files changed, 138 insertions(+) create mode 100644 lightning/src/util/zbase32.rs diff --git a/lightning/src/util/mod.rs b/lightning/src/util/mod.rs index 04b77872c..59b46a4f1 100644 --- a/lightning/src/util/mod.rs +++ b/lightning/src/util/mod.rs @@ -15,6 +15,7 @@ pub(crate) mod fuzz_wrappers; pub mod events; pub mod errors; pub mod ser; +pub mod zbase32; pub(crate) mod byte_utils; pub(crate) mod chacha20; diff --git a/lightning/src/util/zbase32.rs b/lightning/src/util/zbase32.rs new file mode 100644 index 000000000..19a10cca3 --- /dev/null +++ b/lightning/src/util/zbase32.rs @@ -0,0 +1,137 @@ +// This is a modification of base32 encoding to support the zbase32 alphabet. +// The original piece of software can be found at https://github.com/andreasots/base32 + +/* +Copyright (c) 2015 The base32 Developers + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. +*/ + +const ALPHABET: &'static [u8] = b"ybndrfg8ejkmcpqxot1uwisza345h769"; + +pub fn encode(data: &[u8]) -> String { + let mut ret = Vec::with_capacity((data.len() + 3) / 4 * 5); + + for chunk in data.chunks(5) { + let buf = { + let mut buf = [0u8; 5]; + for (i, &b) in chunk.iter().enumerate() { + buf[i] = b; + } + buf + }; + + ret.push(ALPHABET[((buf[0] & 0xF8) >> 3) as usize]); + ret.push(ALPHABET[(((buf[0] & 0x07) << 2) | ((buf[1] & 0xC0) >> 6)) as usize]); + ret.push(ALPHABET[((buf[1] & 0x3E) >> 1) as usize]); + ret.push(ALPHABET[(((buf[1] & 0x01) << 4) | ((buf[2] & 0xF0) >> 4)) as usize]); + ret.push(ALPHABET[(((buf[2] & 0x0F) << 1) | (buf[3] >> 7)) as usize]); + ret.push(ALPHABET[((buf[3] & 0x7C) >> 2) as usize]); + ret.push(ALPHABET[(((buf[3] & 0x03) << 3) | ((buf[4] & 0xE0) >> 5)) as usize]); + ret.push(ALPHABET[(buf[4] & 0x1F) as usize]); + } + + if data.len() % 5 != 0 { + let len = ret.len(); + let num_extra = 8 - (data.len() % 5 * 8 + 4) / 5; + ret.truncate(len - num_extra); + } + + String::from_utf8(ret).unwrap() +} + +// ASCII 0-Z +const INV_ALPHABET: [i8; 43] = [ + -1, 18, -1, 25, 26, 27, 30, 29, 7, 31, -1, -1, -1, -1, -1, -1, -1, 24, 1, 12, 3, 8, 5, 6, 28, + 21, 9, 10, -1, 11, 2, 16, 13, 14, 4, 22, 17, 19, -1, 20, 15, 0, 23, +]; + +pub fn decode(data: &str) -> Result, &'static str> { + if !data.is_ascii() { + return Err("Data is not zbase32 encoded"); + } + + let data = data.as_bytes(); + let output_length = data.len() * 5 / 8; + let mut ret = Vec::with_capacity((output_length + 4) / 5 * 5); + + for chunk in data.chunks(8) { + let buf = { + let mut buf = [0u8; 8]; + for (i, &c) in chunk.iter().enumerate() { + match INV_ALPHABET.get(c.to_ascii_uppercase().wrapping_sub(b'0') as usize) { + Some(&-1) | None => return Err("Data is not zbase32 encoded"), + Some(&value) => buf[i] = value as u8, + }; + } + buf + }; + ret.push((buf[0] << 3) | (buf[1] >> 2)); + ret.push((buf[1] << 6) | (buf[2] << 1) | (buf[3] >> 4)); + ret.push((buf[3] << 4) | (buf[4] >> 1)); + ret.push((buf[4] << 7) | (buf[5] << 2) | (buf[6] >> 3)); + ret.push((buf[6] << 5) | buf[7]); + } + ret.truncate(output_length); + Ok(ret) +} + +mod tests { + use super::*; + + const TEST_DATA: &[(&str, &[u8])] = &[ + ("", &[]), + ("yy", &[0x00]), + ("oy", &[0x80]), + ("tqrey", &[0x8b, 0x88, 0x80]), + ("6n9hq", &[0xf0, 0xbf, 0xc7]), + ("4t7ye", &[0xd4, 0x7a, 0x04]), + ("6im5sdy", &[0xf5, 0x57, 0xbb, 0x0c]), + ("ybndrfg8ejkmcpqxot1uwisza345h769", &[0x00, 0x44, 0x32, 0x14, 0xc7, 0x42, 0x54, 0xb6, + 0x35, 0xcf, 0x84, 0x65, 0x3a, 0x56, 0xd7, 0xc6, + 0x75, 0xbe, 0x77, 0xdf]) + ]; + + + #[test] + fn test_encode() { + for &(zbase32, data) in TEST_DATA { + assert_eq!(encode(data), zbase32); + } + } + + #[test] + fn test_decode() { + for &(zbase32, data) in TEST_DATA { + assert_eq!(decode(zbase32).unwrap(), data); + } + } + + #[test] + fn test_decode_wrong() { + let WRONG_DATA = &["00", "l1", "?", "="]; + + for &data in WRONG_DATA { + match decode(data) { + Ok(_) => assert!(false, "Data shouldn't be decodable"), + Err(_) => assert!(true), + } + } + } +} \ No newline at end of file -- 2.39.5