45 lines
990 B
Rust
45 lines
990 B
Rust
use crate::error::Error;
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pub fn hex_to_bytes(s: &str) -> crate::error::Result<Vec<u8>> {
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let bytes = s.as_bytes();
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if bytes.len() % 2 != 0 {
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return Err(Error::new(format!(
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"hex string must have even length, got {}",
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bytes.len()
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)));
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}
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let mut out = Vec::with_capacity(bytes.len() / 2);
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for chunk in bytes.chunks(2) {
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let hi = match hex_val(chunk[0]) {
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Some(hi) => hi,
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None => {
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return Err(Error::new(format!(
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"invalid hex char '{}'",
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chunk[0] as char
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)));
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}
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};
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let lo = match hex_val(chunk[1]) {
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Some(lo) => lo,
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None => {
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return Err(Error::new(format!(
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"invalid hex char '{}'",
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chunk[1] as char
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)));
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}
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};
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out.push((hi << 4) | lo);
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}
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Ok(out)
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}
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fn hex_val(b: u8) -> Option<u8> {
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match b {
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b'0'..=b'9' => Some(b - b'0'),
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b'a'..=b'f' => Some(b - b'a' + 10),
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b'A'..=b'F' => Some(b - b'A' + 10),
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_ => None,
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}
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}
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