doot/crates/doot-core/src/builtins/crypto.rs

67 lines
1.9 KiB
Rust

//! Pure base64 helpers used by the CLI for encrypted-var handling.
pub fn base64_encode(data: &[u8]) -> String {
const ALPHABET: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
let mut result = String::new();
for chunk in data.chunks(3) {
let b0 = chunk[0] as usize;
let b1 = chunk.get(1).copied().unwrap_or(0) as usize;
let b2 = chunk.get(2).copied().unwrap_or(0) as usize;
result.push(ALPHABET[b0 >> 2] as char);
result.push(ALPHABET[((b0 & 0x03) << 4) | (b1 >> 4)] as char);
if chunk.len() > 1 {
result.push(ALPHABET[((b1 & 0x0f) << 2) | (b2 >> 6)] as char);
} else {
result.push('=');
}
if chunk.len() > 2 {
result.push(ALPHABET[b2 & 0x3f] as char);
} else {
result.push('=');
}
}
result
}
pub fn base64_decode(s: &str) -> Result<Vec<u8>, String> {
const DECODE: [i8; 256] = {
let mut table = [-1i8; 256];
let alphabet = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
let mut i = 0;
while i < 64 {
table[alphabet[i] as usize] = i as i8;
i += 1;
}
table
};
let s = s.trim_end_matches('=');
let mut result = Vec::with_capacity(s.len() * 3 / 4);
let chars: Vec<u8> = s.bytes().collect();
for chunk in chars.chunks(4) {
let mut buf = [0u8; 4];
for (i, &c) in chunk.iter().enumerate() {
let val = DECODE[c as usize];
if val < 0 {
return Err(format!("invalid base64 character: {}", c as char));
}
buf[i] = val as u8;
}
result.push((buf[0] << 2) | (buf[1] >> 4));
if chunk.len() > 2 {
result.push((buf[1] << 4) | (buf[2] >> 2));
}
if chunk.len() > 3 {
result.push((buf[2] << 6) | buf[3]);
}
}
Ok(result)
}