Copied and adapted from: https://github.com/starkware-libs/starkex-resources/tree/844ac3dcb1f735451457f7eecc6e37cd96d1cb2d/crypto/starkware/crypto/signature
A crypto library in js for signing and hashing
Copyright Copyright 2020 StarkWare Industries Ltd.
Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance with the License. You may obtain a copy of the License at
https://www.starkware.co/open-source-license/
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.