libsha256

A minimal library for computing SHA 256 digests.

I created this library because I wanted to have a SHA 256 implementation I could tinker with and integrate easily into other tools for distributed computing.

The implementation in this library is based on the SHA 256 implementation from Git.

You're welcome to use it if you like.

Usage

This library has two main usage modes---one-shot and incremental.

1. One-shot hashing

In one-shot usage, you can compute the digest for a buffer of data you already have in its entirety. In this case, declare a sha256_digest object to store the digest and call sha256. For example:

// Get your data (from somewhere...)
size_t len = ...;
void *data = ...;

// Hash it and use the digest.
sha256_digest d;
sha256(&d, data, len);
do_shit_with(&d);

2. Incremental hashing

In incremental usage, you can compute the digest progressively over incoming ranges of data. In this case, declare a sha256_ctx context object first, and use the sha256_init, sha256_update, and sha256_final functions on it to process data. For example:

// Create a context.
sha256_ctx c;
sha256_init(&c);

// Process data segments.
sha256_update(&c, "Hello", 5);
sha256_update(&c, ", ", 2);
sha256_update(&c, "world!", 6);

// Extract and use the digest.
sha256_digest d;
sha256_final(&d, &c);
do_shit_with(&d);

Installation

You're on your own here. I built this project usng clang and make, so if you have those installed, it-will-probably-just-work. Shouldn't be too hard to be build it yourself using other tools, though.

License

This software is provided under the MIT License. Go wild.