| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/src/rand.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>rand.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../ring/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../ring/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
| <span id="2">2</span> |
| <span id="3">3</span> |
| <span id="4">4</span> |
| <span id="5">5</span> |
| <span id="6">6</span> |
| <span id="7">7</span> |
| <span id="8">8</span> |
| <span id="9">9</span> |
| <span id="10">10</span> |
| <span id="11">11</span> |
| <span id="12">12</span> |
| <span id="13">13</span> |
| <span id="14">14</span> |
| <span id="15">15</span> |
| <span id="16">16</span> |
| <span id="17">17</span> |
| <span id="18">18</span> |
| <span id="19">19</span> |
| <span id="20">20</span> |
| <span id="21">21</span> |
| <span id="22">22</span> |
| <span id="23">23</span> |
| <span id="24">24</span> |
| <span id="25">25</span> |
| <span id="26">26</span> |
| <span id="27">27</span> |
| <span id="28">28</span> |
| <span id="29">29</span> |
| <span id="30">30</span> |
| <span id="31">31</span> |
| <span id="32">32</span> |
| <span id="33">33</span> |
| <span id="34">34</span> |
| <span id="35">35</span> |
| <span id="36">36</span> |
| <span id="37">37</span> |
| <span id="38">38</span> |
| <span id="39">39</span> |
| <span id="40">40</span> |
| <span id="41">41</span> |
| <span id="42">42</span> |
| <span id="43">43</span> |
| <span id="44">44</span> |
| <span id="45">45</span> |
| <span id="46">46</span> |
| <span id="47">47</span> |
| <span id="48">48</span> |
| <span id="49">49</span> |
| <span id="50">50</span> |
| <span id="51">51</span> |
| <span id="52">52</span> |
| <span id="53">53</span> |
| <span id="54">54</span> |
| <span id="55">55</span> |
| <span id="56">56</span> |
| <span id="57">57</span> |
| <span id="58">58</span> |
| <span id="59">59</span> |
| <span id="60">60</span> |
| <span id="61">61</span> |
| <span id="62">62</span> |
| <span id="63">63</span> |
| <span id="64">64</span> |
| <span id="65">65</span> |
| <span id="66">66</span> |
| <span id="67">67</span> |
| <span id="68">68</span> |
| <span id="69">69</span> |
| <span id="70">70</span> |
| <span id="71">71</span> |
| <span id="72">72</span> |
| <span id="73">73</span> |
| <span id="74">74</span> |
| <span id="75">75</span> |
| <span id="76">76</span> |
| <span id="77">77</span> |
| <span id="78">78</span> |
| <span id="79">79</span> |
| <span id="80">80</span> |
| <span id="81">81</span> |
| <span id="82">82</span> |
| <span id="83">83</span> |
| <span id="84">84</span> |
| <span id="85">85</span> |
| <span id="86">86</span> |
| <span id="87">87</span> |
| <span id="88">88</span> |
| <span id="89">89</span> |
| <span id="90">90</span> |
| <span id="91">91</span> |
| <span id="92">92</span> |
| <span id="93">93</span> |
| <span id="94">94</span> |
| <span id="95">95</span> |
| <span id="96">96</span> |
| <span id="97">97</span> |
| <span id="98">98</span> |
| <span id="99">99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| <span id="168">168</span> |
| <span id="169">169</span> |
| <span id="170">170</span> |
| <span id="171">171</span> |
| <span id="172">172</span> |
| <span id="173">173</span> |
| <span id="174">174</span> |
| <span id="175">175</span> |
| <span id="176">176</span> |
| <span id="177">177</span> |
| <span id="178">178</span> |
| <span id="179">179</span> |
| <span id="180">180</span> |
| <span id="181">181</span> |
| <span id="182">182</span> |
| <span id="183">183</span> |
| <span id="184">184</span> |
| <span id="185">185</span> |
| <span id="186">186</span> |
| <span id="187">187</span> |
| <span id="188">188</span> |
| <span id="189">189</span> |
| <span id="190">190</span> |
| <span id="191">191</span> |
| <span id="192">192</span> |
| <span id="193">193</span> |
| <span id="194">194</span> |
| <span id="195">195</span> |
| <span id="196">196</span> |
| <span id="197">197</span> |
| <span id="198">198</span> |
| <span id="199">199</span> |
| <span id="200">200</span> |
| <span id="201">201</span> |
| <span id="202">202</span> |
| <span id="203">203</span> |
| <span id="204">204</span> |
| <span id="205">205</span> |
| <span id="206">206</span> |
| <span id="207">207</span> |
| <span id="208">208</span> |
| <span id="209">209</span> |
| <span id="210">210</span> |
| <span id="211">211</span> |
| <span id="212">212</span> |
| <span id="213">213</span> |
| <span id="214">214</span> |
| <span id="215">215</span> |
| <span id="216">216</span> |
| <span id="217">217</span> |
| <span id="218">218</span> |
| <span id="219">219</span> |
| <span id="220">220</span> |
| <span id="221">221</span> |
| <span id="222">222</span> |
| <span id="223">223</span> |
| <span id="224">224</span> |
| <span id="225">225</span> |
| <span id="226">226</span> |
| <span id="227">227</span> |
| <span id="228">228</span> |
| <span id="229">229</span> |
| <span id="230">230</span> |
| <span id="231">231</span> |
| <span id="232">232</span> |
| <span id="233">233</span> |
| <span id="234">234</span> |
| <span id="235">235</span> |
| <span id="236">236</span> |
| <span id="237">237</span> |
| <span id="238">238</span> |
| <span id="239">239</span> |
| <span id="240">240</span> |
| <span id="241">241</span> |
| <span id="242">242</span> |
| <span id="243">243</span> |
| <span id="244">244</span> |
| <span id="245">245</span> |
| <span id="246">246</span> |
| <span id="247">247</span> |
| <span id="248">248</span> |
| <span id="249">249</span> |
| <span id="250">250</span> |
| <span id="251">251</span> |
| <span id="252">252</span> |
| <span id="253">253</span> |
| <span id="254">254</span> |
| <span id="255">255</span> |
| <span id="256">256</span> |
| <span id="257">257</span> |
| <span id="258">258</span> |
| <span id="259">259</span> |
| <span id="260">260</span> |
| <span id="261">261</span> |
| <span id="262">262</span> |
| <span id="263">263</span> |
| <span id="264">264</span> |
| <span id="265">265</span> |
| <span id="266">266</span> |
| <span id="267">267</span> |
| <span id="268">268</span> |
| <span id="269">269</span> |
| <span id="270">270</span> |
| <span id="271">271</span> |
| <span id="272">272</span> |
| <span id="273">273</span> |
| <span id="274">274</span> |
| <span id="275">275</span> |
| <span id="276">276</span> |
| <span id="277">277</span> |
| <span id="278">278</span> |
| <span id="279">279</span> |
| <span id="280">280</span> |
| <span id="281">281</span> |
| <span id="282">282</span> |
| <span id="283">283</span> |
| <span id="284">284</span> |
| <span id="285">285</span> |
| <span id="286">286</span> |
| <span id="287">287</span> |
| <span id="288">288</span> |
| <span id="289">289</span> |
| <span id="290">290</span> |
| <span id="291">291</span> |
| <span id="292">292</span> |
| <span id="293">293</span> |
| <span id="294">294</span> |
| <span id="295">295</span> |
| <span id="296">296</span> |
| <span id="297">297</span> |
| <span id="298">298</span> |
| <span id="299">299</span> |
| <span id="300">300</span> |
| <span id="301">301</span> |
| <span id="302">302</span> |
| <span id="303">303</span> |
| <span id="304">304</span> |
| <span id="305">305</span> |
| <span id="306">306</span> |
| <span id="307">307</span> |
| <span id="308">308</span> |
| <span id="309">309</span> |
| <span id="310">310</span> |
| <span id="311">311</span> |
| <span id="312">312</span> |
| <span id="313">313</span> |
| <span id="314">314</span> |
| <span id="315">315</span> |
| <span id="316">316</span> |
| <span id="317">317</span> |
| <span id="318">318</span> |
| <span id="319">319</span> |
| <span id="320">320</span> |
| <span id="321">321</span> |
| <span id="322">322</span> |
| <span id="323">323</span> |
| <span id="324">324</span> |
| <span id="325">325</span> |
| <span id="326">326</span> |
| <span id="327">327</span> |
| <span id="328">328</span> |
| <span id="329">329</span> |
| <span id="330">330</span> |
| <span id="331">331</span> |
| <span id="332">332</span> |
| <span id="333">333</span> |
| <span id="334">334</span> |
| <span id="335">335</span> |
| <span id="336">336</span> |
| <span id="337">337</span> |
| <span id="338">338</span> |
| <span id="339">339</span> |
| <span id="340">340</span> |
| <span id="341">341</span> |
| <span id="342">342</span> |
| <span id="343">343</span> |
| <span id="344">344</span> |
| <span id="345">345</span> |
| <span id="346">346</span> |
| <span id="347">347</span> |
| <span id="348">348</span> |
| <span id="349">349</span> |
| <span id="350">350</span> |
| <span id="351">351</span> |
| <span id="352">352</span> |
| <span id="353">353</span> |
| <span id="354">354</span> |
| <span id="355">355</span> |
| <span id="356">356</span> |
| <span id="357">357</span> |
| <span id="358">358</span> |
| <span id="359">359</span> |
| <span id="360">360</span> |
| <span id="361">361</span> |
| <span id="362">362</span> |
| <span id="363">363</span> |
| <span id="364">364</span> |
| <span id="365">365</span> |
| <span id="366">366</span> |
| <span id="367">367</span> |
| <span id="368">368</span> |
| <span id="369">369</span> |
| <span id="370">370</span> |
| <span id="371">371</span> |
| <span id="372">372</span> |
| <span id="373">373</span> |
| <span id="374">374</span> |
| <span id="375">375</span> |
| <span id="376">376</span> |
| <span id="377">377</span> |
| <span id="378">378</span> |
| <span id="379">379</span> |
| <span id="380">380</span> |
| <span id="381">381</span> |
| <span id="382">382</span> |
| <span id="383">383</span> |
| <span id="384">384</span> |
| <span id="385">385</span> |
| <span id="386">386</span> |
| <span id="387">387</span> |
| <span id="388">388</span> |
| <span id="389">389</span> |
| <span id="390">390</span> |
| <span id="391">391</span> |
| <span id="392">392</span> |
| <span id="393">393</span> |
| <span id="394">394</span> |
| <span id="395">395</span> |
| <span id="396">396</span> |
| <span id="397">397</span> |
| <span id="398">398</span> |
| <span id="399">399</span> |
| <span id="400">400</span> |
| <span id="401">401</span> |
| <span id="402">402</span> |
| <span id="403">403</span> |
| <span id="404">404</span> |
| <span id="405">405</span> |
| <span id="406">406</span> |
| <span id="407">407</span> |
| <span id="408">408</span> |
| <span id="409">409</span> |
| <span id="410">410</span> |
| <span id="411">411</span> |
| <span id="412">412</span> |
| <span id="413">413</span> |
| <span id="414">414</span> |
| <span id="415">415</span> |
| <span id="416">416</span> |
| <span id="417">417</span> |
| <span id="418">418</span> |
| <span id="419">419</span> |
| <span id="420">420</span> |
| <span id="421">421</span> |
| <span id="422">422</span> |
| <span id="423">423</span> |
| <span id="424">424</span> |
| <span id="425">425</span> |
| <span id="426">426</span> |
| <span id="427">427</span> |
| <span id="428">428</span> |
| <span id="429">429</span> |
| <span id="430">430</span> |
| <span id="431">431</span> |
| <span id="432">432</span> |
| <span id="433">433</span> |
| </pre><pre class="rust"><code><span class="comment">// Copyright 2015-2016 Brian Smith. |
| // |
| // Permission to use, copy, modify, and/or distribute this software for any |
| // purpose with or without fee is hereby granted, provided that the above |
| // copyright notice and this permission notice appear in all copies. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES |
| // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY |
| // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| </span><span class="doccomment">//! Cryptographic pseudo-random number generation. |
| //! |
| //! An application should create a single `SystemRandom` and then use it for |
| //! all randomness generation. Functions that generate random bytes should take |
| //! a `&dyn SecureRandom` parameter instead of instantiating their own. Besides |
| //! being more efficient, this also helps document where non-deterministic |
| //! (random) outputs occur. Taking a reference to a `SecureRandom` also helps |
| //! with testing techniques like fuzzing, where it is useful to use a |
| //! (non-secure) deterministic implementation of `SecureRandom` so that results |
| //! can be replayed. Following this pattern also may help with sandboxing |
| //! (seccomp filters on Linux in particular). See `SystemRandom`'s |
| //! documentation for more details. |
| |
| </span><span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="doccomment">/// A secure random number generator. |
| </span><span class="kw">pub trait </span>SecureRandom: sealed::SecureRandom { |
| <span class="doccomment">/// Fills `dest` with random bytes. |
| </span><span class="kw">fn </span>fill(<span class="kw-2">&</span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified>; |
| } |
| |
| <span class="kw">impl</span><T> SecureRandom <span class="kw">for </span>T |
| <span class="kw">where |
| </span>T: sealed::SecureRandom, |
| { |
| <span class="attribute">#[inline(always)] |
| </span><span class="kw">fn </span>fill(<span class="kw-2">&</span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="self">self</span>.fill_impl(dest) |
| } |
| } |
| |
| <span class="doccomment">/// A random value constructed from a `SecureRandom` that hasn't been exposed |
| /// through any safe Rust interface. |
| /// |
| /// Intentionally does not implement any traits other than `Sized`. |
| </span><span class="kw">pub struct </span>Random<T: RandomlyConstructable>(T); |
| |
| <span class="kw">impl</span><T: RandomlyConstructable> Random<T> { |
| <span class="doccomment">/// Expose the random value. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>expose(<span class="self">self</span>) -> T { |
| <span class="self">self</span>.<span class="number">0 |
| </span>} |
| } |
| |
| <span class="doccomment">/// Generate the new random value using `rng`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>generate<T: RandomlyConstructable>( |
| rng: <span class="kw-2">&</span><span class="kw">dyn </span>SecureRandom, |
| ) -> <span class="prelude-ty">Result</span><Random<T>, error::Unspecified> |
| <span class="kw">where |
| </span>T: RandomlyConstructable, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>r = T::zero(); |
| rng.fill(r.as_mut_bytes())<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(Random(r)) |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">mod </span>sealed { |
| <span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="kw">pub trait </span>SecureRandom: core::fmt::Debug { |
| <span class="doccomment">/// Fills `dest` with random bytes. |
| </span><span class="kw">fn </span>fill_impl(<span class="kw-2">&</span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified>; |
| } |
| |
| <span class="kw">pub trait </span>RandomlyConstructable: Sized { |
| <span class="kw">fn </span>zero() -> <span class="self">Self</span>; <span class="comment">// `Default::default()` |
| </span><span class="kw">fn </span>as_mut_bytes(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>[u8]; <span class="comment">// `AsMut<[u8]>::as_mut` |
| </span>} |
| |
| <span class="macro">macro_rules! </span>impl_random_arrays { |
| [ $(<span class="macro-nonterminal">$len</span>:expr)+ ] => { |
| $( |
| <span class="kw">impl </span>RandomlyConstructable <span class="kw">for </span>[u8; <span class="macro-nonterminal">$len</span>] { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>zero() -> <span class="self">Self </span>{ [<span class="number">0</span>; <span class="macro-nonterminal">$len</span>] } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>as_mut_bytes(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>[u8] { <span class="kw-2">&mut </span><span class="self">self</span>[..] } |
| } |
| )+ |
| } |
| } |
| |
| <span class="macro">impl_random_arrays!</span>[<span class="number">4 8 16 32 48 64 128 256</span>]; |
| } |
| |
| <span class="doccomment">/// A type that can be returned by `ring::rand::generate()`. |
| </span><span class="kw">pub trait </span>RandomlyConstructable: <span class="self">self</span>::sealed::RandomlyConstructable {} |
| <span class="kw">impl</span><T> RandomlyConstructable <span class="kw">for </span>T <span class="kw">where </span>T: <span class="self">self</span>::sealed::RandomlyConstructable {} |
| |
| <span class="doccomment">/// A secure random number generator where the random values come directly |
| /// from the operating system. |
| /// |
| /// A single `SystemRandom` may be shared across multiple threads safely. |
| /// |
| /// `new()` is guaranteed to always succeed and to have low latency; it won't |
| /// try to open or read from a file or do similar things. The first call to |
| /// `fill()` may block a substantial amount of time since any and all |
| /// initialization is deferred to it. Therefore, it may be a good idea to call |
| /// `fill()` once at a non-latency-sensitive time to minimize latency for |
| /// future calls. |
| /// |
| /// On Linux (including Android), `fill()` will use the [`getrandom`] syscall. |
| /// If the kernel is too old to support `getrandom` then by default `fill()` |
| /// falls back to reading from `/dev/urandom`. This decision is made the first |
| /// time `fill` *succeeds*. The fallback to `/dev/urandom` can be disabled by |
| /// disabling the `dev_urandom_fallback` default feature; this should be done |
| /// whenever the target system is known to support `getrandom`. When |
| /// `/dev/urandom` is used, a file handle for `/dev/urandom` won't be opened |
| /// until `fill` is called; `SystemRandom::new()` will not open `/dev/urandom` |
| /// or do other potentially-high-latency things. The file handle will never be |
| /// closed, until the operating system closes it at process shutdown. All |
| /// instances of `SystemRandom` will share a single file handle. To properly |
| /// implement seccomp filtering when the `dev_urandom_fallback` default feature |
| /// is disabled, allow `getrandom` through. When the fallback is enabled, allow |
| /// file opening, `getrandom`, and `read` up until the first call to `fill()` |
| /// succeeds; after that, allow `getrandom` and `read`. |
| /// |
| /// On macOS and iOS, `fill()` is implemented using `SecRandomCopyBytes`. |
| /// |
| /// On wasm32-unknown-unknown (non-WASI), `fill()` is implemented using |
| /// `window.crypto.getRandomValues()`. It must be used in a context where the |
| /// global object is a `Window`; i.e. it must not be used in a Worker or a |
| /// non-browser context. |
| /// |
| /// On Windows, `fill` is implemented using the platform's API for secure |
| /// random number generation. |
| /// |
| /// [`getrandom`]: http://man7.org/linux/man-pages/man2/getrandom.2.html |
| </span><span class="attribute">#[derive(Clone, Debug)] |
| </span><span class="kw">pub struct </span>SystemRandom(()); |
| |
| <span class="kw">impl </span>SystemRandom { |
| <span class="doccomment">/// Constructs a new `SystemRandom`. |
| </span><span class="attribute">#[inline(always)] |
| </span><span class="kw">pub fn </span>new() -> <span class="self">Self </span>{ |
| <span class="self">Self</span>(()) |
| } |
| } |
| |
| <span class="kw">impl </span>sealed::SecureRandom <span class="kw">for </span>SystemRandom { |
| <span class="attribute">#[inline(always)] |
| </span><span class="kw">fn </span>fill_impl(<span class="kw-2">&</span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| fill_impl(dest) |
| } |
| } |
| |
| <span class="kw">impl </span><span class="kw">crate</span>::sealed::Sealed <span class="kw">for </span>SystemRandom {} |
| |
| <span class="attribute">#[cfg(any( |
| all( |
| any(target_os = <span class="string">"android"</span>, target_os = <span class="string">"linux"</span>), |
| not(feature = <span class="string">"dev_urandom_fallback"</span>) |
| ), |
| target_arch = <span class="string">"wasm32"</span>, |
| windows |
| ))] |
| </span><span class="kw">use </span><span class="self">self</span>::sysrand::fill <span class="kw">as </span>fill_impl; |
| |
| <span class="attribute">#[cfg(all( |
| any(target_os = <span class="string">"android"</span>, target_os = <span class="string">"linux"</span>), |
| feature = <span class="string">"dev_urandom_fallback" |
| </span>))] |
| </span><span class="kw">use </span><span class="self">self</span>::sysrand_or_urandom::fill <span class="kw">as </span>fill_impl; |
| |
| <span class="attribute">#[cfg(any( |
| target_os = <span class="string">"dragonfly"</span>, |
| target_os = <span class="string">"freebsd"</span>, |
| target_os = <span class="string">"illumos"</span>, |
| target_os = <span class="string">"netbsd"</span>, |
| target_os = <span class="string">"openbsd"</span>, |
| target_os = <span class="string">"solaris"</span>, |
| ))] |
| </span><span class="kw">use </span><span class="self">self</span>::urandom::fill <span class="kw">as </span>fill_impl; |
| |
| <span class="attribute">#[cfg(any(target_os = <span class="string">"macos"</span>, target_os = <span class="string">"ios"</span>))] |
| </span><span class="kw">use </span><span class="self">self</span>::darwin::fill <span class="kw">as </span>fill_impl; |
| |
| <span class="attribute">#[cfg(any(target_os = <span class="string">"fuchsia"</span>))] |
| </span><span class="kw">use </span><span class="self">self</span>::fuchsia::fill <span class="kw">as </span>fill_impl; |
| |
| <span class="attribute">#[cfg(any(target_os = <span class="string">"android"</span>, target_os = <span class="string">"linux"</span>))] |
| </span><span class="kw">mod </span>sysrand_chunk { |
| <span class="kw">use crate</span>::{c, error}; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>chunk(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><usize, error::Unspecified> { |
| <span class="kw">use </span>libc::c_long; |
| |
| <span class="comment">// See `SYS_getrandom` in #include <sys/syscall.h>. |
| |
| </span><span class="attribute">#[cfg(target_arch = <span class="string">"aarch64"</span>)] |
| </span><span class="kw">const </span>SYS_GETRANDOM: c_long = <span class="number">278</span>; |
| |
| <span class="attribute">#[cfg(target_arch = <span class="string">"arm"</span>)] |
| </span><span class="kw">const </span>SYS_GETRANDOM: c_long = <span class="number">384</span>; |
| |
| <span class="attribute">#[cfg(target_arch = <span class="string">"x86"</span>)] |
| </span><span class="kw">const </span>SYS_GETRANDOM: c_long = <span class="number">355</span>; |
| |
| <span class="attribute">#[cfg(target_arch = <span class="string">"x86_64"</span>)] |
| </span><span class="kw">const </span>SYS_GETRANDOM: c_long = <span class="number">318</span>; |
| |
| <span class="kw">let </span>chunk_len: c::size_t = dest.len(); |
| <span class="kw">let </span>r = <span class="kw">unsafe </span>{ libc::syscall(SYS_GETRANDOM, dest.as_mut_ptr(), chunk_len, <span class="number">0</span>) }; |
| <span class="kw">if </span>r < <span class="number">0 </span>{ |
| <span class="kw">let </span>errno; |
| |
| <span class="attribute">#[cfg(target_os = <span class="string">"linux"</span>)] |
| </span>{ |
| errno = <span class="kw">unsafe </span>{ <span class="kw-2">*</span>libc::__errno_location() }; |
| } |
| |
| <span class="attribute">#[cfg(target_os = <span class="string">"android"</span>)] |
| </span>{ |
| errno = <span class="kw">unsafe </span>{ <span class="kw-2">*</span>libc::__errno() }; |
| } |
| |
| <span class="kw">if </span>errno == libc::EINTR { |
| <span class="comment">// If an interrupt occurs while getrandom() is blocking to wait |
| // for the entropy pool, then EINTR is returned. Returning 0 |
| // will cause the caller to try again. |
| </span><span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="number">0</span>); |
| } |
| <span class="kw">return </span><span class="prelude-val">Err</span>(error::Unspecified); |
| } |
| <span class="prelude-val">Ok</span>(r <span class="kw">as </span>usize) |
| } |
| } |
| |
| <span class="attribute">#[cfg(all( |
| target_arch = <span class="string">"wasm32"</span>, |
| target_vendor = <span class="string">"unknown"</span>, |
| target_os = <span class="string">"unknown"</span>, |
| target_env = <span class="string">""</span>, |
| ))] |
| </span><span class="kw">mod </span>sysrand_chunk { |
| <span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="kw">pub fn </span>chunk(<span class="kw-2">mut </span>dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><usize, error::Unspecified> { |
| <span class="comment">// This limit is specified in |
| // https://www.w3.org/TR/WebCryptoAPI/#Crypto-method-getRandomValues. |
| </span><span class="kw">const </span>MAX_LEN: usize = <span class="number">65_536</span>; |
| <span class="kw">if </span>dest.len() > MAX_LEN { |
| dest = <span class="kw-2">&mut </span>dest[..MAX_LEN]; |
| }; |
| |
| <span class="kw">let _ </span>= web_sys::window() |
| .ok_or(error::Unspecified)<span class="question-mark">? |
| </span>.crypto() |
| .map_err(|<span class="kw">_</span>| error::Unspecified)<span class="question-mark">? |
| </span>.get_random_values_with_u8_array(dest) |
| .map_err(|<span class="kw">_</span>| error::Unspecified)<span class="question-mark">?</span>; |
| |
| <span class="prelude-val">Ok</span>(dest.len()) |
| } |
| } |
| |
| <span class="attribute">#[cfg(windows)] |
| </span><span class="kw">mod </span>sysrand_chunk { |
| <span class="kw">use crate</span>::{error, polyfill}; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>chunk(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><usize, error::Unspecified> { |
| <span class="kw">use </span>winapi::shared::wtypesbase::ULONG; |
| |
| <span class="macro">assert!</span>(core::mem::size_of::<usize>() >= core::mem::size_of::<ULONG>()); |
| <span class="kw">let </span>len = core::cmp::min(dest.len(), polyfill::usize_from_u32(ULONG::max_value())); |
| <span class="kw">let </span>result = <span class="kw">unsafe </span>{ |
| winapi::um::ntsecapi::RtlGenRandom( |
| dest.as_mut_ptr() <span class="kw">as </span><span class="kw-2">*mut </span>winapi::ctypes::c_void, |
| len <span class="kw">as </span>ULONG, |
| ) |
| }; |
| <span class="kw">if </span>result == <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(error::Unspecified); |
| } |
| |
| <span class="prelude-val">Ok</span>(len) |
| } |
| } |
| |
| <span class="attribute">#[cfg(any( |
| target_os = <span class="string">"android"</span>, |
| target_os = <span class="string">"linux"</span>, |
| target_arch = <span class="string">"wasm32"</span>, |
| windows |
| ))] |
| </span><span class="kw">mod </span>sysrand { |
| <span class="kw">use </span><span class="kw">super</span>::sysrand_chunk::chunk; |
| <span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="kw">pub fn </span>fill(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">let </span><span class="kw-2">mut </span>read_len = <span class="number">0</span>; |
| <span class="kw">while </span>read_len < dest.len() { |
| <span class="kw">let </span>chunk_len = chunk(<span class="kw-2">&mut </span>dest[read_len..])<span class="question-mark">?</span>; |
| read_len += chunk_len; |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| } |
| |
| <span class="comment">// Keep the `cfg` conditions in sync with the conditions in lib.rs. |
| </span><span class="attribute">#[cfg(all( |
| any(target_os = <span class="string">"android"</span>, target_os = <span class="string">"linux"</span>), |
| feature = <span class="string">"dev_urandom_fallback" |
| </span>))] |
| </span><span class="kw">mod </span>sysrand_or_urandom { |
| <span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="kw">enum </span>Mechanism { |
| Sysrand, |
| DevURandom, |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>fill(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">use </span>once_cell::sync::Lazy; |
| <span class="kw">static </span>MECHANISM: Lazy<Mechanism> = Lazy::new(|| { |
| <span class="kw">let </span><span class="kw-2">mut </span>dummy = [<span class="number">0u8</span>; <span class="number">1</span>]; |
| <span class="kw">if </span><span class="kw">super</span>::sysrand_chunk::chunk(<span class="kw-2">&mut </span>dummy[..]).is_err() { |
| Mechanism::DevURandom |
| } <span class="kw">else </span>{ |
| Mechanism::Sysrand |
| } |
| }); |
| |
| <span class="kw">match </span><span class="kw-2">*</span>MECHANISM { |
| Mechanism::Sysrand => <span class="kw">super</span>::sysrand::fill(dest), |
| Mechanism::DevURandom => <span class="kw">super</span>::urandom::fill(dest), |
| } |
| } |
| } |
| |
| <span class="attribute">#[cfg(any( |
| all( |
| any(target_os = <span class="string">"android"</span>, target_os = <span class="string">"linux"</span>), |
| feature = <span class="string">"dev_urandom_fallback" |
| </span>), |
| target_os = <span class="string">"dragonfly"</span>, |
| target_os = <span class="string">"freebsd"</span>, |
| target_os = <span class="string">"netbsd"</span>, |
| target_os = <span class="string">"openbsd"</span>, |
| target_os = <span class="string">"solaris"</span>, |
| target_os = <span class="string">"illumos" |
| </span>))] |
| </span><span class="kw">mod </span>urandom { |
| <span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="attribute">#[cfg_attr(any(target_os = <span class="string">"android"</span>, target_os = <span class="string">"linux"</span>), cold, inline(never))] |
| </span><span class="kw">pub fn </span>fill(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">extern crate </span>std; |
| |
| <span class="kw">use </span>once_cell::sync::Lazy; |
| |
| <span class="kw">static </span>FILE: Lazy<<span class="prelude-ty">Result</span><std::fs::File, std::io::Error>> = |
| Lazy::new(|| std::fs::File::open(<span class="string">"/dev/urandom"</span>)); |
| |
| <span class="kw">match </span><span class="kw-2">*</span>FILE { |
| <span class="prelude-val">Ok</span>(<span class="kw-2">ref </span>file) => { |
| <span class="kw">use </span>std::io::Read; |
| (<span class="kw-2">&*</span>file).read_exact(dest).map_err(|<span class="kw">_</span>| error::Unspecified) |
| } |
| <span class="prelude-val">Err</span>(<span class="kw">_</span>) => <span class="prelude-val">Err</span>(error::Unspecified), |
| } |
| } |
| } |
| |
| <span class="attribute">#[cfg(any(target_os = <span class="string">"macos"</span>, target_os = <span class="string">"ios"</span>))] |
| </span><span class="kw">mod </span>darwin { |
| <span class="kw">use crate</span>::{c, error}; |
| |
| <span class="kw">pub fn </span>fill(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">let </span>r = <span class="kw">unsafe </span>{ SecRandomCopyBytes(kSecRandomDefault, dest.len(), dest.as_mut_ptr()) }; |
| <span class="kw">match </span>r { |
| <span class="number">0 </span>=> <span class="prelude-val">Ok</span>(()), |
| <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(error::Unspecified), |
| } |
| } |
| |
| <span class="comment">// XXX: This is emulating an opaque type with a non-opaque type. TODO: Fix |
| // this when |
| // https://github.com/rust-lang/rfcs/pull/1861#issuecomment-274613536 is |
| // resolved. |
| </span><span class="attribute">#[repr(C)] |
| </span><span class="kw">struct </span>SecRandomRef([u8; <span class="number">0</span>]); |
| |
| <span class="attribute">#[link(name = <span class="string">"Security"</span>, kind = <span class="string">"framework"</span>)] |
| </span><span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">static </span>kSecRandomDefault: <span class="kw-2">&</span><span class="lifetime">'static </span>SecRandomRef; |
| |
| <span class="comment">// For now `rnd` must be `kSecRandomDefault`. |
| </span><span class="attribute">#[must_use] |
| </span><span class="kw">fn </span>SecRandomCopyBytes( |
| rnd: <span class="kw-2">&</span><span class="lifetime">'static </span>SecRandomRef, |
| count: c::size_t, |
| bytes: <span class="kw-2">*mut </span>u8, |
| ) -> c::int; |
| } |
| } |
| |
| <span class="attribute">#[cfg(any(target_os = <span class="string">"fuchsia"</span>))] |
| </span><span class="kw">mod </span>fuchsia { |
| <span class="kw">use </span><span class="kw">crate</span>::error; |
| |
| <span class="kw">pub fn </span>fill(dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">unsafe </span>{ |
| zx_cprng_draw(dest.as_mut_ptr(), dest.len()); |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="attribute">#[link(name = <span class="string">"zircon"</span>)] |
| </span><span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">fn </span>zx_cprng_draw(buffer: <span class="kw-2">*mut </span>u8, length: usize); |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="ring" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |