/// Encodes some bytes as a zbase32 string
pub fn encode(data: &[u8]) -> String {
- let mut ret = Vec::with_capacity((data.len() + 4) / 5 * 8);
-
- 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]);
- }
-
- ret.truncate((data.len() * 8 + 4) / 5);
-
- // Check that our capacity calculation doesn't under-shoot in fuzzing
- #[cfg(fuzzing)]
- assert_eq!(ret.capacity(), (data.len() + 4) / 5 * 8);
-
- String::from_utf8(ret).unwrap()
+ let mut ret = Vec::with_capacity((data.len() + 4) / 5 * 8);
+
+ 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]);
+ }
+
+ ret.truncate((data.len() * 8 + 4) / 5);
+
+ // Check that our capacity calculation doesn't under-shoot in fuzzing
+ #[cfg(fuzzing)]
+ assert_eq!(ret.capacity(), (data.len() + 4) / 5 * 8);
+
+ 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,
+ -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,
];
/// Decodes a zbase32 string to the original bytes, failing if the string was not encoded by a
/// proper zbase32 encoder.
pub fn decode(data: &str) -> Result<Vec<u8>, ()> {
- if !data.is_ascii() {
- return Err(());
- }
-
- let data = data.as_bytes();
- let output_length = data.len() * 5 / 8;
- if data.len() > (output_length * 8 + 4) / 5 {
- // If the string has more charachters than are required to encode the number of bytes
- // decodable, treat the string as invalid.
- return Err(());
- }
-
- let mut ret = Vec::with_capacity((data.len() + 7) / 8 * 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(()),
- 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]);
- }
- for c in ret.drain(output_length..) {
- if c != 0 {
- // If the original string had any bits set at positions outside of the encoded data,
- // treat the string as invalid.
- return Err(());
- }
- }
-
- // Check that our capacity calculation doesn't under-shoot in fuzzing
- #[cfg(fuzzing)]
- assert_eq!(ret.capacity(), (data.len() + 7) / 8 * 5);
-
- Ok(ret)
+ if !data.is_ascii() {
+ return Err(());
+ }
+
+ let data = data.as_bytes();
+ let output_length = data.len() * 5 / 8;
+ if data.len() > (output_length * 8 + 4) / 5 {
+ // If the string has more charachters than are required to encode the number of bytes
+ // decodable, treat the string as invalid.
+ return Err(());
+ }
+
+ let mut ret = Vec::with_capacity((data.len() + 7) / 8 * 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(()),
+ 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]);
+ }
+ for c in ret.drain(output_length..) {
+ if c != 0 {
+ // If the original string had any bits set at positions outside of the encoded data,
+ // treat the string as invalid.
+ return Err(());
+ }
+ }
+
+ // Check that our capacity calculation doesn't under-shoot in fuzzing
+ #[cfg(fuzzing)]
+ assert_eq!(ret.capacity(), (data.len() + 7) / 8 * 5);
+
+ Ok(ret)
}
#[cfg(test)]
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() {
- const WRONG_DATA: &[&str] = &["00", "l1", "?", "="];
-
- for &data in WRONG_DATA {
- match decode(data) {
- Ok(_) => assert!(false, "Data shouldn't be decodable"),
- Err(_) => assert!(true),
- }
- }
- }
+ 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() {
+ const WRONG_DATA: &[&str] = &["00", "l1", "?", "="];
+
+ for &data in WRONG_DATA {
+ match decode(data) {
+ Ok(_) => assert!(false, "Data shouldn't be decodable"),
+ Err(_) => assert!(true),
+ }
+ }
+ }
}
projects / rust-lightning / commitdiff