# crypto
A crypto library for the Odin language

## Supported
This library offers various algorithms implemented in Odin.
Please see the chart below for the options.  

## Hashing algorithms
| Algorithm                                                                                                    |                  |
|:-------------------------------------------------------------------------------------------------------------|:-----------------|
| [BLAKE](https://web.archive.org/web/20190915215948/https://131002.net/blake)                                 | &#10004;&#65039; |
| [BLAKE2B](https://datatracker.ietf.org/doc/html/rfc7693)                                                     | &#10004;&#65039; |
| [BLAKE2S](https://datatracker.ietf.org/doc/html/rfc7693)                                                     | &#10004;&#65039; |
| [GOST](https://datatracker.ietf.org/doc/html/rfc5831)                                                        | &#10004;&#65039; |
| [Grøstl](http://www.groestl.info/Groestl.zip)                                                                | &#10004;&#65039; |
| [HAVAL](https://web.archive.org/web/20150111210116/http://labs.calyptix.com/haval.php)                       | &#10004;&#65039; |
| [JH](https://www3.ntu.edu.sg/home/wuhj/research/jh/index.html)                                               | &#10004;&#65039; |
| [Keccak](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                           | &#10004;&#65039; |
| [MD2](https://datatracker.ietf.org/doc/html/rfc1319)                                                         | &#10004;&#65039; |
| [MD4](https://datatracker.ietf.org/doc/html/rfc1320)                                                         | &#10004;&#65039; |
| [MD5](https://datatracker.ietf.org/doc/html/rfc1321)                                                         | &#10004;&#65039; |
| [RIPEMD](https://homes.esat.kuleuven.be/~bosselae/ripemd160.html)                                            | &#10004;&#65039; |
| [SHA-1](https://datatracker.ietf.org/doc/html/rfc3174)                                                       | &#10004;&#65039; |
| [SHA-2](https://csrc.nist.gov/csrc/media/publications/fips/180/2/archive/2002-08-01/documents/fips180-2.pdf) | &#10004;&#65039; |
| [SHA-3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                            | &#10004;&#65039; |
| [SHAKE](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                            | &#10004;&#65039; |
| [SM3](https://datatracker.ietf.org/doc/html/draft-sca-cfrg-sm3-02)                                           | &#10004;&#65039; |
| [Streebog](https://datatracker.ietf.org/doc/html/rfc6986)                                                    | &#10004;&#65039; |
| [Tiger](https://www.cs.technion.ac.il/~biham/Reports/Tiger/)                                                 | &#10004;&#65039; |
| [Tiger2](https://www.cs.technion.ac.il/~biham/Reports/Tiger/)                                                | &#10004;&#65039; |
| [Whirlpool](https://web.archive.org/web/20171129084214/http://www.larc.usp.br/~pbarreto/WhirlpoolPage.html)  | &#10004;&#65039; |

#### High level API
Each hash algorithm contains a procedure group named `hash`, or if the algorithm provides more than one digest size `hash_<size>`\*.  
Included in these groups are six procedures.
* `hash_string` - Hash a given string and return the computed hash. Just calls `hash_bytes` internally
* `hash_bytes` - Hash a given byte slice and return the computed hash
* `hash_string_to_buffer` - Hash a given string and put the computed hash in the second proc parameter. Just calls `hash_bytes_to_buffer` internally
* `hash_bytes_to_buffer` - Hash a given string and put the computed hash in the second proc parameter. The destination buffer has to be at least as big as the digest size of the hash
* `hash_stream` - Takes a stream from io.Stream and returns the computed hash from it
* `hash_file` - Takes a file handle and returns the computed hash from it. A second optional boolean parameter controls if the file is streamed (this is the default) or read at once (set to true)

\* On some algorithms there is another part to the name, since they might offer control about additional parameters.  
For instance, `HAVAL` offers different sizes as well as three different round amounts.  
Computing a 256-bit hash with 3 rounds is therefore achieved by calling `haval.hash_256_3(...)`.

#### Low level API
The above mentioned procedures internally call three procedures: `init`, `update` and `final`.
You may also directly call them, if you wish.

#### Example
```odin
package crypto_example

// Import the desired package
import "core:crypto/md4"

main :: proc() {
    input := "foo"

    // Compute the hash, using the high level API
    computed_hash := md4.hash(input)

    // Variant that takes a destination buffer, instead of returning the computed hash
    hash := make([]byte, md4.DIGEST_SIZE) // @note: Destination buffer has to be at least as big as the digest size of the hash
    md4.hash(input, hash[:])

    // Compute the hash, using the low level API
    ctx: md4.Md4_Context
    computed_hash_low: [16]byte
    md4.init(&ctx)
    md4.update(&ctx, transmute([]byte)input)
    md4.final(&ctx, computed_hash_low[:])
}
```
For example uses of all available algorithms, please see the tests within `tests/core/crypto`.

#### Thread safety
The crypto package is not thread-safe at the moment. This may change in the future.

### Disclaimer
The algorithms were ported out of curiosity and due to interest in the field.
We have not had any of the code verified by a third party or tested/fuzzed by any automatic means.
Wherever we were able to find official test vectors, those were used to verify the implementation.
We do not recommend using them in a production environment, without any additional testing and/or verification.

### ToDo
* Ciphers (Symmetric, Asymmetric)
* MACs (Message Authentication Code)
* CSPRNGs (Cryptographically Secure PseudoRandom Number Generator)
* KDFs (Key Derivation Function)
* KEAs (Key Exchange Algorithm)

### License
This library is made available under the BSD-3 license.