Files
relicario/extension/src/shared/base32.ts
2026-04-20 19:44:18 -04:00

45 lines
1.2 KiB
TypeScript

/// Minimal RFC 4648 base32 encode/decode for TOTP secret parsing.
///
/// Mirrors the encoder in crates/relicario-core/src/item.rs:base32_encode.
/// Decode is case-insensitive, tolerates whitespace and `=` padding.
const ALPHA = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
export function base32Encode(bytes: Uint8Array): string {
let out = '';
let buffer = 0;
let bits = 0;
for (const b of bytes) {
buffer = (buffer << 8) | b;
bits += 8;
while (bits >= 5) {
const idx = (buffer >> (bits - 5)) & 0x1f;
out += ALPHA[idx];
bits -= 5;
}
}
if (bits > 0) {
const idx = (buffer << (5 - bits)) & 0x1f;
out += ALPHA[idx];
}
return out;
}
export function base32Decode(input: string): Uint8Array {
const cleaned = input.replace(/\s+/g, '').replace(/=+$/g, '').toUpperCase();
const out: number[] = [];
let buffer = 0;
let bits = 0;
for (const ch of cleaned) {
const idx = ALPHA.indexOf(ch);
if (idx === -1) throw new Error(`base32: invalid character "${ch}"`);
buffer = (buffer << 5) | idx;
bits += 5;
if (bits >= 8) {
out.push((buffer >> (bits - 8)) & 0xff);
bits -= 8;
}
}
return new Uint8Array(out);
}