| <!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="Shared secret derivation."><meta name="keywords" content="rust, rustlang, rust-lang, derive"><title>openssl::derive - Rust</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="../../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 mod"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../openssl/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../openssl/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Module derive</a></h2><div class="sidebar-elems"><section><ul class="block"><li><a href="#structs">Structs</a></li></ul></section></div></nav><main><div class="width-limiter"><nav class="sub"><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="main-heading"><h1 class="fqn">Module <a href="../index.html">openssl</a>::<wbr><a class="mod" href="#">derive</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/openssl/derive.rs.html#1-182">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Shared secret derivation.</p> |
| <h2 id="example"><a href="#example">Example</a></h2> |
| <p>The following example implements <a href="https://wiki.openssl.org/index.php/Elliptic_Curve_Diffie_Hellman">ECDH</a> using <code>NIST P-384</code> keys:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>openssl::bn::BigNumContext; |
| <span class="kw">use </span>openssl::pkey::PKey; |
| <span class="kw">use </span>openssl::derive::Deriver; |
| <span class="kw">use </span>openssl::ec::{EcGroup, EcKey, EcPoint, PointConversionForm}; |
| <span class="kw">use </span>openssl::nid::Nid; |
| |
| <span class="kw">let </span>group = EcGroup::from_curve_name(Nid::SECP384R1)<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>first: PKey<<span class="kw">_</span>> = EcKey::generate(<span class="kw-2">&</span>group)<span class="question-mark">?</span>.try_into()<span class="question-mark">?</span>; |
| |
| <span class="comment">// second party generates an ephemeral key and derives |
| // a shared secret using first party's public key |
| </span><span class="kw">let </span>shared_key = EcKey::generate(<span class="kw-2">&</span>group)<span class="question-mark">?</span>; |
| <span class="comment">// shared_public is sent to first party |
| </span><span class="kw">let </span><span class="kw-2">mut </span>ctx = BigNumContext::new()<span class="question-mark">?</span>; |
| <span class="kw">let </span>shared_public = shared_key.public_key().to_bytes( |
| <span class="kw-2">&</span>group, |
| PointConversionForm::COMPRESSED, |
| <span class="kw-2">&mut </span>ctx, |
| )<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>shared_key: PKey<<span class="kw">_</span>> = shared_key.try_into()<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>deriver = Deriver::new(<span class="kw-2">&</span>shared_key)<span class="question-mark">?</span>; |
| deriver.set_peer(<span class="kw-2">&</span>first)<span class="question-mark">?</span>; |
| <span class="comment">// secret can be used e.g. as a symmetric encryption key |
| </span><span class="kw">let </span>secret = deriver.derive_to_vec()<span class="question-mark">?</span>; |
| |
| <span class="comment">// first party derives the same shared secret using |
| // shared_public |
| </span><span class="kw">let </span>point = EcPoint::from_bytes(<span class="kw-2">&</span>group, <span class="kw-2">&</span>shared_public, <span class="kw-2">&mut </span>ctx)<span class="question-mark">?</span>; |
| <span class="kw">let </span>recipient_key: PKey<<span class="kw">_</span>> = EcKey::from_public_key(<span class="kw-2">&</span>group, <span class="kw-2">&</span>point)<span class="question-mark">?</span>.try_into()<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>deriver = Deriver::new(<span class="kw-2">&</span>first)<span class="question-mark">?</span>; |
| deriver.set_peer(<span class="kw-2">&</span>recipient_key)<span class="question-mark">?</span>; |
| <span class="kw">let </span>first_secret = deriver.derive_to_vec()<span class="question-mark">?</span>; |
| |
| <span class="macro">assert_eq!</span>(secret, first_secret);</code></pre></div> |
| </div></details><h2 id="structs" class="small-section-header"><a href="#structs">Structs</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Deriver.html" title="openssl::derive::Deriver struct">Deriver</a></div><div class="item-right docblock-short">A type used to derive a shared secret between two keys.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="openssl" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
