Graphorin API reference v0.4.0
Graphorin API reference / @graphorin/security / / encodeBase62Bytes
Function: encodeBase62Bytes()
function encodeBase62Bytes(bytes, width): string;Defined in: packages/security/src/auth/token-format.ts:204
Encode a byte buffer as base62 with a fixed-length output. The routine treats the bytes as a big-endian unbounded integer and left-pads to width so that any 32-byte input yields exactly 43 base62 characters.
Bias note (CodeQL js/biased-cryptographic-random): this is not a byte % 62 reduction over CSPRNG bytes — that would indeed bias the output. Instead we perform full big-integer long division, so each emitted base62 character represents a distinct "digit" of the input integer in base 62. As long as the input is uniform over [0, 256^n) (which is what crypto.randomBytes(n) guarantees), the resulting base62 string is uniform over [0, 62^width) for the leading positions; only the most-significant position can carry a small bias when 256^n is not an exact power of 62, and that position is what width left-pads to a constant length for. Callers that need fixed-entropy tokens should pick n such that 256^n >= 62^width — the existing encodeRandomToken helpers do.
Parameters
| Parameter | Type |
|---|---|
bytes | Uint8Array |
width | number |
Returns
string