mchost / src/encoding.rs

//! Minimal percent-encoding/decoding for the bridge shared secret.

const UNRESERVED: &[u8] = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.~";

/// Percent-encode everything outside the unreserved set.
pub fn percent_encode(input: &str) -> String {
    let mut out = String::with_capacity(input.len());
    for byte in input.bytes() {
        if UNRESERVED.contains(&byte) {
            out.push(byte as char);
        } else {
            out.push_str(&format!("%{byte:02X}"));
        }
    }
    out
}

/// Decode `%XX` escapes. `+` is left alone (never produced by `percent_encode`).
pub fn percent_decode(input: &str) -> String {
    let bytes = input.as_bytes();
    let mut out = Vec::with_capacity(bytes.len());
    let mut i = 0;
    while i < bytes.len() {
        if bytes[i] == b'%' && i + 2 < bytes.len() {
            let hex = &input[i + 1..i + 3];
            if let Ok(byte) = u8::from_str_radix(hex, 16) {
                out.push(byte);
                i += 3;
                continue;
            }
        }
        out.push(bytes[i]);
        i += 1;
    }
    String::from_utf8_lossy(&out).into_owned()
}