neco-cid

日本語

A minimal CIDv1 library with only a sha2 dependency, providing CID computation and multibase encode/decode for IPLD and AT Protocol use cases.

Features

Single dependency: sha2 (core functionality)
CIDv1 compute, byte serialization, and deserialization
Multibase encode/decode (base32lower, b prefix)
Supported codecs: dag-cbor (0x71), raw (0x55)
Hash function: SHA-256 only

Usage

Compute a CID

use neco_cid::{Cid, Codec, Base};

let data = b"hello world";
let cid = Cid::compute(Codec::DagCbor, data);

let s = cid.to_multibase(Base::Base32Lower);
// base32lower string like "bafyrei..."

Decode from a CID string

use neco_cid::Cid;

let cid = Cid::from_multibase("bafyreib...").unwrap();

Round-trip through bytes

use neco_cid::Cid;

let bytes = cid.to_bytes();
let (cid2, consumed) = Cid::from_bytes(&bytes).unwrap();
assert_eq!(cid, cid2);
assert_eq!(consumed, bytes.len());

API

`Cid`

Represents a CIDv1. Implements Debug, Clone, PartialEq, Eq, Hash.

Item	Description
`Cid::compute(codec: Codec, data: &[u8]) -> Cid`	Compute a CID from the SHA-256 hash of data
`Cid::from_bytes(input: &[u8]) -> Result<(Cid, usize), CidError>`	Deserialize a CID from bytes, returning the number of bytes consumed
`Cid::to_bytes(&self) -> Vec<u8>`	Serialize the CID to bytes
`Cid::to_multibase(&self, base: Base) -> String`	Encode the CID as a multibase string in the given base
`Cid::from_multibase(input: &str) -> Result<Cid, CidError>`	Decode a CID from a multibase string
`Cid::codec(&self) -> Codec`	Return the codec
`Cid::digest(&self) -> &[u8; 32]`	Return the SHA-256 digest

`Codec`

Variant	Value	Description
`Codec::DagCbor`	`0x71`	DAG-CBOR
`Codec::Raw`	`0x55`	Raw bytes

`Base`

Variant	Prefix	Description
`Base::Base32Lower`	`b`	RFC 4648 base32 lowercase, no padding

`CidError`

Variant	Description
`InvalidVersion(u64)`	Version other than CIDv1
`UnsupportedCodec(u64)`	Unsupported codec code
`UnsupportedHashCode(u64)`	Unsupported hash function code
`InvalidDigestLength`	Digest length is not 32 bytes
`InvalidMultibase`	Malformed multibase string
`UnexpectedEnd`	Input ended prematurely

License

MIT

neco-cid 0.2.0