# Kotlin Multiplatform Crypto Library

Kotlin Multiplatform Crypto is a library for various cryptographic applications. 

This is an extremely early release, currently only consisting of Blake2b and SHA256 and 512.

## Notes & Roadmap

**The API will move fast and break often until v1.0**

Make SHA hashes "updateable" like Blake2b

After that tenative plan is to add 25519 curve based signing and key exchange next.

## Should I use this in production?

No, it's untested and unproven. 

## Supported

## Hashing functions
* Blake2b
* SHA512
* SHA256

More to come.

## Integration

#### Gradle
```kotlin
implementation("com.ionspin.kotlin:crypto:0.0.1")
```

#### Snapshot builds
```kotlin
repositories {
    maven {
        url = uri("https://oss.sonatype.org/content/repositories/snapshots")
    }
}
implementation("com.ionspin.kotlin:crypto:0.0.1-SNAPSHOT")

```

## Usage

### Blake2b

You can use Blake 2b in two modes

#### Using a `Blake2b` object
You need to deliver the complete data that is to be hashed in one go

```kotlin
val input = "abc"
val result = Blake2b.digest(input)
```

Result is returned as a `Array<Byte>`

#### Using a `Blake2b` instance
You can create an instance and feed the data by using `update(input : Array<Byte>)` call. Once all data is supplied,
you should call `digest()` or `digestString()` convinence method that converts the `Array<Byte>` into hexadecimal string.

If you want to use Blake2b with a key, you should supply it when creating the `Blake2b` instance.

```kotlin
val test = "abc"
val key = "key"
val blake2b = Blake2b(key)
blake2b.update(test)
val result = blake2b.digest()
```

After digest is called, the instance is reset and can be reused (Keep in mind key stays the same for the particular instance).
### SHA2 (SHA256 and SHA512)

You need to deliver the complete data that is to be hashed in one go. You can either provide the `Array<Byte>` as input
or `String`. Result is always returned as `Array<Byte>` (At least in verision 0.0.1)

```kotlin
val input = "abc"
val result = Sha256.digest(input)
```

```kotlin
val input ="abc"
val result = Sha512.digest(message = input.encodeToByteArray().map { it.toUByte() }.toTypedArray())
```

Result is returned as a `Array<Byte>`