SHAmwow/README.md

# SHAmwow

Sometimes you just want to understand how your hashing algorithms work, so you implement them yourself.

It should go without saying that this was just for fun, and you should never, ever, _ever_ roll your own cryptography primatives for any  purpose other than education!

## Talk

I gave a talk on this project at [Papers We Love NYC](http://paperswelove.org/2017/video/david-ashby-shamwow/)! The [PDF](https://github.com/deltamualpha/shamwow/blob/master/slides.pdf), [Keynote file](https://github.com/deltamualpha/shamwow/blob/master/slides.key), and [PDF-with-nodes](https://github.com/deltamualpha/shamwow/blob/master/slides-with-notes.pdf) of the slides are also in this repo.

## sha1

The sha1 function in `shamwow.rb` implements the SHA1 hashing function in Ruby, outputting the 160-bit hash as a hexadecimal string.

### sources

* wikipedia's pseudocode breakdown: <https://en.wikipedia.org/wiki/SHA-1#Examples_and_pseudocode>

## sha2

The sha2 function in `shamwow.rb` implements the SHA-256 hashing function in Ruby, outputting the 256-bit hash as a hexadecimal string.

### Sources

* the actual spec: <http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf>
* wikipedia's pseudocode breakdown: <https://en.wikipedia.org/wiki/SHA-2#Pseudocode>
* a JS implementation that helped as I was debugging some boneheaded mistakes: <http://www.movable-type.co.uk/scripts/sha256.html>

## Tests

`shamwow_test.rb` contains a few sanity tests for the bit-rotation functions and for the hashes themselves, testing against the output of the `Digest` gem in the standard library.

## Obligatory

[![ShamWOW](https://img.youtube.com/vi/F3lrhPeK6gU/0.jpg)](https://www.youtube.com/watch?v=F3lrhPeK6gU)
initial commit 2017-08-30 00:36:14 +00:00			`# SHAmwow`

extra s 2017-09-04 02:22:24 +00:00			`Sometimes you just want to understand how your hashing algorithms work, so you implement them yourself.`
initial commit 2017-08-30 00:36:14 +00:00
update readme with SHA1 2017-09-04 02:21:46 +00:00			`It should go without saying that this was just for fun, and you should never, ever, _ever_ roll your own cryptography primatives for any purpose other than education!`
initial commit 2017-08-30 00:36:14 +00:00
add info on talk and link to slides 2018-01-08 23:46:25 +00:00			`## Talk`

			`I gave a talk on this project at [Papers We Love NYC](http://paperswelove.org/2017/video/david-ashby-shamwow/)! The [PDF](https://github.com/deltamualpha/shamwow/blob/master/slides.pdf), [Keynote file](https://github.com/deltamualpha/shamwow/blob/master/slides.key), and [PDF-with-nodes](https://github.com/deltamualpha/shamwow/blob/master/slides-with-notes.pdf) of the slides are also in this repo.`

update readme with SHA1 2017-09-04 02:21:46 +00:00			`## sha1`
initial commit 2017-08-30 00:36:14 +00:00
update readme with SHA1 2017-09-04 02:21:46 +00:00			The sha1 function in `shamwow.rb` implements the SHA1 hashing function in Ruby, outputting the 160-bit hash as a hexadecimal string.
initial commit 2017-08-30 00:36:14 +00:00
update readme with SHA1 2017-09-04 02:21:46 +00:00			`### sources`

			`* wikipedia's pseudocode breakdown: <https://en.wikipedia.org/wiki/SHA-1#Examples_and_pseudocode>`

			`## sha2`

			The sha2 function in `shamwow.rb` implements the SHA-256 hashing function in Ruby, outputting the 256-bit hash as a hexadecimal string.

			`### Sources`
initial commit 2017-08-30 00:36:14 +00:00
			`* the actual spec: <http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf>`
			`* wikipedia's pseudocode breakdown: <https://en.wikipedia.org/wiki/SHA-2#Pseudocode>`
			`* a JS implementation that helped as I was debugging some boneheaded mistakes: <http://www.movable-type.co.uk/scripts/sha256.html>`

update readme with SHA1 2017-09-04 02:21:46 +00:00			`## Tests`

			`shamwow_test.rb` contains a few sanity tests for the bit-rotation functions and for the hashes themselves, testing against the output of the `Digest` gem in the standard library.

initial commit 2017-08-30 00:36:14 +00:00			`## Obligatory`

fix that embed, of course github doesn't allow that 2017-08-30 00:38:56 +00:00			`[![ShamWOW](https://img.youtube.com/vi/F3lrhPeK6gU/0.jpg)](https://www.youtube.com/watch?v=F3lrhPeK6gU)`