https://github.com/jtdowney/hkdf

Rubygem for HMAC-based Key Derivation Function
https://github.com/jtdowney/hkdf

Last synced: 3 months ago
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Rubygem for HMAC-based Key Derivation Function

• Host: GitHub
• URL: https://github.com/jtdowney/hkdf
• Owner: jtdowney
• License: mit
• Created: 2012-04-14T16:01:39.000Z (almost 13 years ago)
• Default Branch: main
• Last Pushed: 2021-04-27T15:36:27.000Z (over 3 years ago)
• Last Synced: 2024-09-19T21:07:08.254Z (4 months ago)
• Language: Ruby
• Homepage:
• Size: 43.9 KB
• Stars: 15
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE
  • Code of conduct: CODE_OF_CONDUCT.md

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README

        
# HKDF

[![CI](https://github.com/jtdowney/hkdf/actions/workflows/ci.yml/badge.svg)](https://github.com/jtdowney/hkdf/actions/workflows/ci.yml)

[![Gem Version](https://badge.fury.io/rb/hkdf.svg)](https://badge.fury.io/rb/hkdf)

This is a ruby implementation of [RFC 5869](http://tools.ietf.org/html/rfc5869): HMAC-based Extract-and-Expand Key Derivation Function. The goal of HKDF is to take some source key material and generate suitable cryptographic keys from it.

## Usage

```ruby

hkdf = HKDF.new('source key material')

hkdf.read(32)

 => "\f#\xF4b\x98\x9B\x7Fw>|/|k\xF4k\xB7\xB9\x11e\xC5\x92\xD1\fH\xFDG\x94vt\xB4\x14\xCE"

```

The default algorithm is HMAC-SHA256, you can override this and other defaults by providing an options hash during construction.

```ruby

hkdf = HKDF.new('source key material', :salt => 'NaCl', :algorithm => 'SHA1', :info => 'the 411')

hkdf.read(16)

 => "\xC0<\x13\x85\x8C\x84z\xCE\xC7\xCE+\xFF\x1C\xEB\xE6\xBC"

```

You can also give an IO object as the source. It will be read in as a stream to generate the key. The optional argument `:read_size` can be used to control how many bytes are read from the IO at a time.

```ruby

hkdf = HKDF.new(File.new('/tmp/filename'), :read_size => 512)

hkdf.read(32)

 => "\f#\xF4b\x98\x9B\x7Fw>|/|k\xF4k\xB7\xB9\x11e\xC5\x92\xD1\fH\xFDG\x94vt\xB4\x14\xCE"

```

## Requirements

- Ruby >= 2.4