ma_core/
multiformat.rs

1use unsigned_varint::{decode, encode};
2
3use crate::error::{MaError, MaResult as Result};
4
5// Well-known multicodec codec identifiers for payload encoding.
6// Key/signature codecs live in key.rs.
7// Source: https://github.com/multiformats/multicodec/blob/master/table.csv
8pub const CODEC_IDENTITY: u64 = 0x00;
9pub const CODEC_RAW: u64 = 0x55;
10pub const CODEC_CBOR: u64 = 0x51;
11pub const CODEC_DAG_CBOR: u64 = 0x71;
12pub const CODEC_DAG_JSON: u64 = 0x0129;
13pub const CODEC_JSON: u64 = 0x0200;
14
15pub fn multibase_encode(data: &[u8]) -> String {
16    multibase::encode(multibase::Base::Base58Btc, data)
17}
18
19pub fn multibase_decode(input: &str) -> Result<Vec<u8>> {
20    multibase::decode(input)
21        .map(|(_, data)| data)
22        .map_err(|_| MaError::InvalidPublicKeyMultibase)
23}
24
25pub fn multicodec_encode(codec: u64, payload: &[u8]) -> Vec<u8> {
26    let mut buffer = encode::u64_buffer();
27    let prefix = encode::u64(codec, &mut buffer);
28    let mut out = prefix.to_vec();
29    out.extend_from_slice(payload);
30    out
31}
32
33pub fn multicodec_decode(encoded: &[u8]) -> Result<(u64, Vec<u8>)> {
34    let (codec, remainder) =
35        decode::u64(encoded).map_err(|_| MaError::InvalidPublicKeyMultibase)?;
36    if remainder.is_empty() {
37        return Err(MaError::InvalidPublicKeyMultibase);
38    }
39    Ok((codec, remainder.to_vec()))
40}
41
42pub fn public_key_multibase_encode(codec: u64, public_key: &[u8]) -> String {
43    multibase_encode(&multicodec_encode(codec, public_key))
44}
45
46pub fn public_key_multibase_decode(input: &str) -> Result<(u64, Vec<u8>)> {
47    let decoded = multibase_decode(input)?;
48    multicodec_decode(&decoded)
49}
50
51pub fn signature_multibase_encode(codec: u64, signature: &[u8]) -> String {
52    multibase_encode(&multicodec_encode(codec, signature))
53}
54
55pub fn signature_multibase_decode(input: &str) -> Result<(u64, Vec<u8>)> {
56    let decoded = multibase_decode(input)?;
57    multicodec_decode(&decoded)
58}
59
60#[cfg(test)]
61mod tests {
62    use super::*;
63
64    #[test]
65    fn multicodec_round_trip_dag_cbor() {
66        let payload = b"hello dag-cbor";
67        let encoded = multicodec_encode(CODEC_DAG_CBOR, payload);
68        let (codec, decoded) = multicodec_decode(&encoded).unwrap();
69        assert_eq!(codec, CODEC_DAG_CBOR);
70        assert_eq!(decoded, payload);
71    }
72
73    #[test]
74    fn multicodec_round_trip_identity() {
75        let payload = b"raw bytes";
76        let encoded = multicodec_encode(CODEC_IDENTITY, payload);
77        let (codec, decoded) = multicodec_decode(&encoded).unwrap();
78        assert_eq!(codec, CODEC_IDENTITY);
79        assert_eq!(decoded.as_slice(), payload);
80    }
81
82    #[test]
83    fn multicodec_round_trip_large_codec_varint() {
84        // CODEC_DAG_JSON (0x0129) requires a 2-byte varint — exercises multi-byte encoding.
85        let payload = b"json payload";
86        let encoded = multicodec_encode(CODEC_DAG_JSON, payload);
87        let (codec, decoded) = multicodec_decode(&encoded).unwrap();
88        assert_eq!(codec, CODEC_DAG_JSON);
89        assert_eq!(decoded.as_slice(), payload);
90    }
91
92    #[test]
93    fn multicodec_decode_empty_payload_fails() {
94        // A valid varint prefix with no payload following it should be rejected.
95        let mut buf = unsigned_varint::encode::u64_buffer();
96        let prefix = unsigned_varint::encode::u64(CODEC_CBOR, &mut buf);
97        assert!(multicodec_decode(prefix).is_err());
98    }
99
100    #[test]
101    fn multicodec_decode_empty_slice_fails() {
102        assert!(multicodec_decode(&[]).is_err());
103    }
104
105    #[test]
106    fn multibase_round_trip() {
107        let data = b"test data 12345";
108        let encoded = multibase_encode(data);
109        assert!(
110            encoded.starts_with('z'),
111            "base58btc multibase prefix is 'z'"
112        );
113        let decoded = multibase_decode(&encoded).unwrap();
114        assert_eq!(decoded, data);
115    }
116
117    #[test]
118    fn multibase_decode_invalid_input_fails() {
119        assert!(multibase_decode("!!!not-valid!!!").is_err());
120    }
121
122    #[test]
123    fn public_key_multibase_round_trip() {
124        // Use the Ed25519 public key codec (0xed).
125        let codec = 0xed_u64;
126        let key_bytes = [42u8; 32];
127        let encoded = public_key_multibase_encode(codec, &key_bytes);
128        let (decoded_codec, decoded_bytes) = public_key_multibase_decode(&encoded).unwrap();
129        assert_eq!(decoded_codec, codec);
130        assert_eq!(decoded_bytes.as_slice(), &key_bytes);
131    }
132
133    #[test]
134    fn signature_multibase_round_trip() {
135        // Use the EdDSA signature codec (0xd0ed).
136        let codec = 0xd0ed_u64;
137        let sig_bytes = [99u8; 64];
138        let encoded = signature_multibase_encode(codec, &sig_bytes);
139        let (decoded_codec, decoded_bytes) = signature_multibase_decode(&encoded).unwrap();
140        assert_eq!(decoded_codec, codec);
141        assert_eq!(decoded_bytes.as_slice(), &sig_bytes);
142    }
143
144    #[test]
145    fn multicodec_encode_prepends_prefix_bytes() {
146        // CODEC_IDENTITY = 0x00 → single zero byte prefix.
147        let payload = b"x";
148        let encoded = multicodec_encode(CODEC_IDENTITY, payload);
149        assert_eq!(encoded[0], 0x00);
150        assert_eq!(&encoded[1..], payload);
151    }
152}
ma_core/multiformat.rs

ma_core/
multiformat.rs
