| <!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/git/checkouts/incubator-teaclave-crates-c8106113f74feefc/ede1f68/ring/src/ec/curve25519/x25519.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>x25519.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> |
| </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">//! X25519 Key agreement. |
| |
| </span><span class="kw">use super</span>::{ops, scalar::SCALAR_LEN}; |
| <span class="kw">use crate</span>::{agreement, constant_time, cpu, ec, error, rand}; |
| <span class="kw">use </span>core::convert::TryInto; |
| |
| <span class="kw">static </span>CURVE25519: ec::Curve = ec::Curve { |
| public_key_len: PUBLIC_KEY_LEN, |
| elem_scalar_seed_len: ELEM_AND_SCALAR_LEN, |
| id: ec::CurveID::Curve25519, |
| check_private_key_bytes: x25519_check_private_key_bytes, |
| generate_private_key: x25519_generate_private_key, |
| public_from_private: x25519_public_from_private, |
| }; |
| |
| <span class="doccomment">/// X25519 (ECDH using Curve25519) as described in [RFC 7748]. |
| /// |
| /// Everything is as described in RFC 7748. Key agreement will fail if the |
| /// result of the X25519 operation is zero; see the notes on the |
| /// "all-zero value" in [RFC 7748 section 6.1]. |
| /// |
| /// [RFC 7748]: https://tools.ietf.org/html/rfc7748 |
| /// [RFC 7748 section 6.1]: https://tools.ietf.org/html/rfc7748#section-6.1 |
| </span><span class="kw">pub static </span>X25519: agreement::Algorithm = agreement::Algorithm { |
| curve: <span class="kw-2">&</span>CURVE25519, |
| ecdh: x25519_ecdh, |
| }; |
| |
| <span class="kw">fn </span>x25519_check_private_key_bytes(bytes: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="macro">debug_assert_eq!</span>(bytes.len(), PRIVATE_KEY_LEN); |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>x25519_generate_private_key( |
| rng: <span class="kw-2">&</span><span class="kw">dyn </span>rand::SecureRandom, |
| out: <span class="kw-2">&mut </span>[u8], |
| ) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| rng.fill(out) |
| } |
| |
| <span class="kw">fn </span>x25519_public_from_private( |
| public_out: <span class="kw-2">&mut </span>[u8], |
| private_key: <span class="kw-2">&</span>ec::Seed, |
| ) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">let </span>public_out = public_out.try_into()<span class="question-mark">?</span>; |
| |
| <span class="attribute">#[cfg(target_arch = <span class="string">"arm"</span>)] |
| </span><span class="kw">let </span>cpu_features = private_key.cpu_features; |
| |
| <span class="kw">let </span>private_key: <span class="kw-2">&</span>[u8; SCALAR_LEN] = private_key.bytes_less_safe().try_into()<span class="question-mark">?</span>; |
| <span class="kw">let </span>private_key = ops::MaskedScalar::from_bytes_masked(<span class="kw-2">*</span>private_key); |
| |
| <span class="attribute">#[cfg(all(not(target_os = <span class="string">"ios"</span>), target_arch = <span class="string">"arm"</span>))] |
| </span>{ |
| <span class="kw">if </span>cpu::arm::NEON.available(cpu_features) { |
| <span class="kw">static </span>MONTGOMERY_BASE_POINT: [u8; <span class="number">32</span>] = [ |
| <span class="number">9</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, |
| <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, |
| ]; |
| x25519_neon(public_out, <span class="kw-2">&</span>private_key, <span class="kw-2">&</span>MONTGOMERY_BASE_POINT); |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(()); |
| } |
| } |
| |
| <span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">fn </span>GFp_x25519_public_from_private_generic_masked( |
| public_key_out: <span class="kw-2">&mut </span>PublicKey, |
| private_key: <span class="kw-2">&</span>PrivateKey, |
| ); |
| } |
| <span class="kw">unsafe </span>{ |
| GFp_x25519_public_from_private_generic_masked(public_out, <span class="kw-2">&</span>private_key); |
| } |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>x25519_ecdh( |
| out: <span class="kw-2">&mut </span>[u8], |
| my_private_key: <span class="kw-2">&</span>ec::Seed, |
| peer_public_key: untrusted::Input, |
| ) -> <span class="prelude-ty">Result</span><(), error::Unspecified> { |
| <span class="kw">let </span>cpu_features = my_private_key.cpu_features; |
| <span class="kw">let </span>my_private_key: <span class="kw-2">&</span>[u8; SCALAR_LEN] = my_private_key.bytes_less_safe().try_into()<span class="question-mark">?</span>; |
| <span class="kw">let </span>my_private_key = ops::MaskedScalar::from_bytes_masked(<span class="kw-2">*</span>my_private_key); |
| <span class="kw">let </span>peer_public_key: <span class="kw-2">&</span>[u8; PUBLIC_KEY_LEN] = peer_public_key.as_slice_less_safe().try_into()<span class="question-mark">?</span>; |
| |
| <span class="attribute">#[cfg_attr( |
| not(all(not(target_os = <span class="string">"ios"</span>), target_arch = <span class="string">"arm"</span>)), |
| allow(unused_variables) |
| )] |
| </span><span class="kw">fn </span>scalar_mult( |
| out: <span class="kw-2">&mut </span>ops::EncodedPoint, |
| scalar: <span class="kw-2">&</span>ops::MaskedScalar, |
| point: <span class="kw-2">&</span>ops::EncodedPoint, |
| cpu_features: cpu::Features, |
| ) { |
| <span class="attribute">#[cfg(all(not(target_os = <span class="string">"ios"</span>), target_arch = <span class="string">"arm"</span>))] |
| </span>{ |
| <span class="kw">if </span>cpu::arm::NEON.available(cpu_features) { |
| <span class="kw">return </span>x25519_neon(out, scalar, point); |
| } |
| } |
| |
| <span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">fn </span>GFp_x25519_scalar_mult_generic_masked( |
| out: <span class="kw-2">&mut </span>ops::EncodedPoint, |
| scalar: <span class="kw-2">&</span>ops::MaskedScalar, |
| point: <span class="kw-2">&</span>ops::EncodedPoint, |
| ); |
| } |
| <span class="kw">unsafe </span>{ |
| GFp_x25519_scalar_mult_generic_masked(out, scalar, point); |
| } |
| } |
| |
| scalar_mult( |
| out.try_into()<span class="question-mark">?</span>, |
| <span class="kw-2">&</span>my_private_key, |
| peer_public_key, |
| cpu_features, |
| ); |
| |
| <span class="kw">let </span>zeros: SharedSecret = [<span class="number">0</span>; SHARED_SECRET_LEN]; |
| <span class="kw">if </span>constant_time::verify_slices_are_equal(out, <span class="kw-2">&</span>zeros).is_ok() { |
| <span class="comment">// All-zero output results when the input is a point of small order. |
| </span><span class="kw">return </span><span class="prelude-val">Err</span>(error::Unspecified); |
| } |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="attribute">#[cfg(all(not(target_os = <span class="string">"ios"</span>), target_arch = <span class="string">"arm"</span>))] |
| </span><span class="kw">fn </span>x25519_neon(out: <span class="kw-2">&mut </span>ops::EncodedPoint, scalar: <span class="kw-2">&</span>ops::MaskedScalar, point: <span class="kw-2">&</span>ops::EncodedPoint) { |
| <span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">fn </span>GFp_x25519_NEON( |
| out: <span class="kw-2">&mut </span>ops::EncodedPoint, |
| scalar: <span class="kw-2">&</span>ops::MaskedScalar, |
| point: <span class="kw-2">&</span>ops::EncodedPoint, |
| ); |
| } |
| <span class="kw">unsafe </span>{ GFp_x25519_NEON(out, scalar, point) } |
| } |
| |
| <span class="kw">const </span>ELEM_AND_SCALAR_LEN: usize = ops::ELEM_LEN; |
| |
| <span class="kw">type </span>PrivateKey = ops::MaskedScalar; |
| <span class="kw">const </span>PRIVATE_KEY_LEN: usize = ELEM_AND_SCALAR_LEN; |
| |
| <span class="comment">// An X25519 public key as an encoded Curve25519 point. |
| </span><span class="kw">type </span>PublicKey = [u8; PUBLIC_KEY_LEN]; |
| <span class="kw">const </span>PUBLIC_KEY_LEN: usize = ELEM_AND_SCALAR_LEN; |
| |
| <span class="comment">// An X25519 shared secret as an encoded Curve25519 point. |
| </span><span class="kw">type </span>SharedSecret = [u8; SHARED_SECRET_LEN]; |
| <span class="kw">const </span>SHARED_SECRET_LEN: usize = ELEM_AND_SCALAR_LEN; |
| </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> |
