Crate c32

Rust implementation of Crockford’s Base32 encoding scheme.

Implementation

• Lightweight — The core functionality has zero external dependencies.
• Portable — Fully compatible with #![no_std] environments.
• Safe — Implemented entirely in safe Rust with no unsafe blocks.

let bytes = b"usque ad finem";
let encoded = c32::encode(&bytes);
assert_eq!(encoded, "1TQ6WBNCMG62S10CSMPWSBD");

let bytes = b"usque ad finem";
let decoded = c32::decode("1TQ6WBNCMG62S10CSMPWSBD")?;
assert_eq!(decoded, bytes);

In #![no_std] Environments

For environments without allocation support, the library provides buffer-based APIs:

// encoding with a pre-allocated buffer
let bytes = b"usque ad finem";
let mut buffer = [0; 32];

let written = c32::encode_into(bytes, &mut buffer)?;
let encoded = &buffer[..written];
assert_eq!(encoded, b"1TQ6WBNCMG62S10CSMPWSBD");

// decoding with a pre-allocated buffer
let encoded = b"1TQ6WBNCMG62S10CSMPWSBD";
let mut buffer = [0; 32];

let written = c32::decode_into(encoded, &mut buffer)?;
let decoded = &buffer[..written];
assert_eq!(decoded, b"usque ad finem");

Checksums

The check feature enables methods for encoding data with SHA256-based checksum verification.

The encoded data follows this layout:

[version (1B)] + [payload (nB)] + [checksum (4B)]

And is computed by…

1. Concatenating the version byte with the payload bytes.
2. Taking the SHA256 hash of the concatenated bytes.
3. Taking the SHA256 hash of the result.
4. Using the first 4 bytes as the checksum.

Examples

let bytes = b"usque ad finem";
let encoded = c32::encode_check(bytes, 22)?;
assert_eq!(encoded, "P7AWVHENJJ0RB441K6JVK5DNJ7J3V5");

let encoded = "P7AWVHENJJ0RB441K6JVK5DNJ7J3V5";
let (decoded, version) = c32::decode_check(encoded)?;
assert_eq!(decoded, b"usque ad finem");
assert_eq!(version, 22);

Features

Feature	Description
alloc	Allocation-based API via encode and decode
check	Support for checksum validation

For more details, please refer to the full API Reference.

Modules

checksumcheck

This module provides methods for computing SHA-256 checksums.

en

Encoding implementations.

Structs

Buffer

A fixed-size buffer for encoding or decoding Crockford’s Base32.

Enums

Error

Error variants for fallible Crockford Base32 operations.

Traits

Encoding

A marker trait for Crockford Base32 variations.

Functions

decodealloc

Decodes a Crockford Base32-encoded string.

decode_checkalloc and check

Decodes a Crockford Base32Check-encoded string.

decode_check_intocheck

Decodes Crockford Base32Check-encoded bytes into a provided buffer.

decode_check_prefixedalloc and check

Decodes a prefixed Crockford Base32Check-encoded string.

decode_into

Decodes Crockford Base32-encoded bytes into a provided buffer.

decode_prefixedalloc

Decodes a prefixed Crockford Base32-encoded string.

decoded_check_lencheck

Computes the required capacity for decoding from Crockford Base32Check.

decoded_len

Computes the required capacity for decoding from Crockford Base32.

encodealloc

Encodes bytes into a Crockford Base32-encoded string.

encode_checkalloc and check

Encodes bytes into a Crockford Base32Check-encoded string.

encode_check_intocheck

Encodes bytes as Crockford Base32Check into a provided buffer.

encode_check_prefixedalloc and check

Encodes bytes into a prefixed Crockford Base32Check-encoded string.

encode_into

Encodes bytes as Crockford Base32 into a provided buffer.

encode_prefixedalloc

Encodes bytes into a prefixed Crockford Base32-encoded string.

encoded_check_lencheck

Computes the required capacity for encoding into Crockford Base32Check.

encoded_len

Computes the required capacity for encoding into Crockford Base32.

Type Aliases

Result

Result type for fallible Crockford Base32 operations.