1
0
Fork 0
mirror of https://gitlab.redox-os.org/CoffeeCode/redox-ssh.git synced 2025-12-28 18:42:18 +01:00
redox-ssh/crypto/fortuna/index.html

166 lines
No EOL
7.1 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="rustdoc">
<meta name="description" content="API documentation for the Rust `fortuna` mod in crate `crypto`.">
<meta name="keywords" content="rust, rustlang, rust-lang, fortuna">
<title>crypto::fortuna - Rust</title>
<link rel="stylesheet" type="text/css" href="../../normalize.css">
<link rel="stylesheet" type="text/css" href="../../rustdoc.css">
<link rel="stylesheet" type="text/css" href="../../main.css">
</head>
<body class="rustdoc mod">
<!--[if lte IE 8]>
<div class="warning">
This old browser is unsupported and will most likely display funky
things.
</div>
<![endif]-->
<nav class="sidebar">
<p class='location'>Module fortuna</p><div class="block items"><ul><li><a href="#structs">Structs</a></li><li><a href="#constants">Constants</a></li></ul></div><p class='location'><a href='../index.html'>crypto</a></p><script>window.sidebarCurrent = {name: 'fortuna', ty: 'mod', relpath: '../'};</script><script defer src="../sidebar-items.js"></script>
</nav>
<nav class="sub">
<form class="search-form js-only">
<div class="search-container">
<input class="search-input" name="search"
autocomplete="off"
placeholder="Click or press S to search, ? for more options…"
type="search">
</div>
</form>
</nav>
<section id='main' class="content">
<h1 class='fqn'><span class='in-band'>Module <a href='../index.html'>crypto</a>::<wbr><a class="mod" href=''>fortuna</a></span><span class='out-of-band'><span id='render-detail'>
<a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">
[<span class='inner'>&#x2212;</span>]
</a>
</span><a class='srclink' href='../../src/crypto/fortuna.rs.html#7-515' title='goto source code'>[src]</a></span></h1>
<div class='docblock'><p>An implementation of the Fortuna CSPRNG</p>
<p>First create a <code>FortunaRng</code> object using either the <code>new_unseeded</code>
constructor or <code>SeedableRng::from_seed</code>. Additional entropy may be
added using the method <code>add_random_event</code>, or the underlying RNG
maybe reseeded directly by <code>SeedableRng::reseed</code>. Note that this is
not recommended, since the generator automatically reseeds itself
using the data provided by <code>add_random_events</code> through an
accumulator. The accumulator is part of Fortuna&#39;s design and using
<code>SeedableRng::reseed</code> directly bypasses it.</p>
<p>Note that the underlying block cipher is <code>AesSafe256Encryptor</code> which
is designed to be timing-attack resistant. The speed hit from this
is in line with a &quot;safety first&quot; API, but be aware of it.</p>
<p>Fortuna was originally described in
Practical Cryptography, Niels Ferguson and Bruce Schneier.
John Wiley &amp; Sons, 2003.</p>
<p>Comments throughout this file contain references of the form
(PC 1.2.3); these refer to sections within this text.</p>
<h1 id='a-note-on-forking' class='section-header'><a href='#a-note-on-forking'>A note on forking</a></h1>
<p>Proper behaviour for a CSRNG on a process fork is to reseed itself with
the timestamp and new process ID, to ensure that after forking the child
process does not share the same RNG state (and therefore the same output)
as its parent.</p>
<p>However, this appears not to be possible in Rust, due to
<a href="https://github.com/rust-lang/rust/issues/16799">https://github.com/rust-lang/rust/issues/16799</a>
The reason is that Rust&#39;s process management all happens through its
stdlib runtime, which explicitly does not support forking, so it provides
no mechanism with which to detect forks.</p>
<p>What this means is that if you are writing forking code (using <code>#![no_std]</code>
say) then you need to EXPLICITLY RESEED THE RNG AFTER FORKING.</p>
</div><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table>
<tr class=' module-item'>
<td><a class="struct" href="struct.Fortuna.html"
title='struct crypto::fortuna::Fortuna'>Fortuna</a></td>
<td class='docblock-short'>
<p>The <code>Fortuna</code> CSPRNG (PC 9.5)</p>
</td>
</tr></table><h2 id='constants' class='section-header'><a href="#constants">Constants</a></h2>
<table>
<tr class=' module-item'>
<td><a class="constant" href="constant.MIN_POOL_SIZE.html"
title='constant crypto::fortuna::MIN_POOL_SIZE'>MIN_POOL_SIZE</a></td>
<td class='docblock-short'>
<p>Length in bytes that the first pool must be before a &quot;catastrophic
reseed&quot; is allowed to happen. (A direct reseed through the
<code>SeedableRng</code> API is not affected by this limit.)</p>
</td>
</tr></table></section>
<section id='search' class="content hidden"></section>
<section class="footer"></section>
<aside id="help" class="hidden">
<div>
<h1 class="hidden">Help</h1>
<div class="shortcuts">
<h2>Keyboard Shortcuts</h2>
<dl>
<dt>?</dt>
<dd>Show this help dialog</dd>
<dt>S</dt>
<dd>Focus the search field</dd>
<dt>&larrb;</dt>
<dd>Move up in search results</dd>
<dt>&rarrb;</dt>
<dd>Move down in search results</dd>
<dt>&#9166;</dt>
<dd>Go to active search result</dd>
<dt>+</dt>
<dd>Collapse/expand all sections</dd>
</dl>
</div>
<div class="infos">
<h2>Search Tricks</h2>
<p>
Prefix searches with a type followed by a colon (e.g.
<code>fn:</code>) to restrict the search to a given type.
</p>
<p>
Accepted types are: <code>fn</code>, <code>mod</code>,
<code>struct</code>, <code>enum</code>,
<code>trait</code>, <code>type</code>, <code>macro</code>,
and <code>const</code>.
</p>
<p>
Search functions by type signature (e.g.
<code>vec -> usize</code> or <code>* -> vec</code>)
</p>
</div>
</div>
</aside>
<script>
window.rootPath = "../../";
window.currentCrate = "crypto";
</script>
<script src="../../main.js"></script>
<script defer src="../../search-index.js"></script>
</body>
</html>