Self-Addressing Identifier (SAI) provides a compact text representation of digests of data. It supports multiple hash algorithms.
Self Addressing Identifier is base64 encoded hash of data, prepended with one or two letter prefix, called derivation code. Derivation code determines which hash algorithm was used to derive the digest.
| derivation code| digest type | code length | identifier length | |---------------|-------------------|---------------|-------------------| | E | Blake3-256 Digest | 1 | 44 | | F | Blake2b-256 Digest| 1 | 44 | | G | Blake2s-256 Digest| 1 | 44 | | H | SHA3-256 Digest | 1 | 44 | | I | SHA2-256 Digest | 1 | 44 | | 0D | Blake3-512 Digest | 2 | 88 | | 0E | Blake2b-512 Digest| 2 | 88 | | 0F | SHA3-512 Digest | 2 | 88 | | 0G | SHA2-512 Digest | 2 | 88 |
To derive Self Addressing Identifier, SelfAddressing
enum can be used. It
determines hashing algorithm used for Identifier derivation. Here are its
possible values:
rust
pub enum SelfAddressing {
Blake3_256,
Blake2B256(Vec<u8>),
Blake2S256(Vec<u8>),
SHA3_256,
SHA2_256,
Blake3_512,
SHA3_512,
Blake2B512,
SHA2_512,
}
verify_bindings
function checks if provided data matches digest encoded in Self Addressing Identifier.
```rust let data = "hello there"; let sai = SelfAddressing::Blake3256.derive(data.asbytes());
asserteq!(format!("{}", sai), "E2bCqepXGid9s1nSEyKk4kljbl3GULx5JjkFvIwJ8sk"); assert!(sai.verifybinding(data.asbytes())); assert!(!sai.verifybinding("wrong data".asbytes())); ```
bindings/sai_wasm
directory contains a project which allows to compile sai library to wasm.