# Cryptography primitives for Exonum
[](https://travis-ci.com/exonum/exonum)
[](https://github.com/exonum/exonum/blob/master/LICENSE)

`exonum-crypto` provides a high-level API for work with various cryptography tasks.
Capabilities of `exonum-crypto` include:
- Calculating the hash of data;
- Generating key pairs for work with digital signatures;
- Creating and verifying of digital signatures.
The main backend for `exonum-crypto` is `sodiumoxide`, and the used algorithms are:
- SHA-256 for hashing.
- Ed25519 for digital signatures.
Consult [the crate docs](https://docs.rs/exonum-crypto) for more details.
## Examples
Signing data and verifying the signature:
```rust
exonum_crypto::init();
let (public_key, secret_key) = exonum_crypto::gen_keypair();
let data = [1, 2, 3];
let signature = exonum_crypto::sign(&data, &secret_key);
assert!(exonum_crypto::verify(&signature, &data, &public_key));
```
Hashing fixed amount of data:
```rust
exonum_crypto::init();
let data = [1, 2, 3];
let hash = exonum_crypto::hash(&data);
```
Hashing data by chunks:
```rust
use exonum_crypto::HashStream;
exonum_crypto::init();
let data: Vec<[u8; 5]> = vec![[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]];
let mut hash_stream = HashStream::new();
for chunk in data {
hash_stream = hash_stream.update(&chunk);
}
let _ = hash_stream.hash();
```
## Usage
Include `exonum-crypto` as a dependency in your `Cargo.toml`:
```toml
[dependencies]
exonum-crypto = "1.0.0"
```
## License
`exonum-crypto` is licensed under the Apache License (Version 2.0).
See [LICENSE](LICENSE) for details.