| <!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="HMAC is specified in RFC 2104."><meta name="keywords" content="rust, rustlang, rust-lang, hmac"><title>ring::hmac - 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="../../ring/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="../../ring/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Module hmac</a></h2><div class="sidebar-elems"><section><ul class="block"><li><a href="#structs">Structs</a></li><li><a href="#statics">Statics</a></li><li><a href="#functions">Functions</a></li><li><a href="#types">Type Definitions</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">ring</a>::<wbr><a class="mod" href="#">hmac</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/ring/hmac.rs.html#15-385">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>HMAC is specified in <a href="https://tools.ietf.org/html/rfc2104">RFC 2104</a>.</p> |
| <p>After a <code>Key</code> is constructed, it can be used for multiple signing or |
| verification operations. Separating the construction of the key from the |
| rest of the HMAC operation allows the per-key precomputation to be done |
| only once, instead of it being done in every HMAC operation.</p> |
| <p>Frequently all the data to be signed in a message is available in a single |
| contiguous piece. In that case, the module-level <code>sign</code> function can be |
| used. Otherwise, if the input is in multiple parts, <code>Context</code> should be |
| used.</p> |
| <h2 id="examples"><a href="#examples">Examples:</a></h2><h3 id="signing-a-value-and-verifying-it-wasnt-tampered-with"><a href="#signing-a-value-and-verifying-it-wasnt-tampered-with">Signing a value and verifying it wasn’t tampered with</a></h3> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>ring::{hmac, rand}; |
| |
| <span class="kw">let </span>rng = rand::SystemRandom::new(); |
| <span class="kw">let </span>key = hmac::Key::generate(hmac::HMAC_SHA256, <span class="kw-2">&</span>rng)<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>msg = <span class="string">"hello, world"</span>; |
| |
| <span class="kw">let </span>tag = hmac::sign(<span class="kw-2">&</span>key, msg.as_bytes()); |
| |
| <span class="comment">// [We give access to the message to an untrusted party, and they give it |
| // back to us. We need to verify they didn't tamper with it.] |
| |
| </span>hmac::verify(<span class="kw-2">&</span>key, msg.as_bytes(), tag.as_ref())<span class="question-mark">?</span>; |
| </code></pre></div> |
| <h3 id="using-the-one-shot-api"><a href="#using-the-one-shot-api">Using the one-shot API:</a></h3> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>ring::{digest, hmac, rand}; |
| <span class="kw">use </span>ring::rand::SecureRandom; |
| |
| <span class="kw">let </span>msg = <span class="string">"hello, world"</span>; |
| |
| <span class="comment">// The sender generates a secure key value and signs the message with it. |
| // Note that in a real protocol, a key agreement protocol would be used to |
| // derive `key_value`. |
| </span><span class="kw">let </span>rng = rand::SystemRandom::new(); |
| <span class="kw">let </span>key_value: [u8; digest::SHA256_OUTPUT_LEN] = rand::generate(<span class="kw-2">&</span>rng)<span class="question-mark">?</span>.expose(); |
| |
| <span class="kw">let </span>s_key = hmac::Key::new(hmac::HMAC_SHA256, key_value.as_ref()); |
| <span class="kw">let </span>tag = hmac::sign(<span class="kw-2">&</span>s_key, msg.as_bytes()); |
| |
| <span class="comment">// The receiver (somehow!) knows the key value, and uses it to verify the |
| // integrity of the message. |
| </span><span class="kw">let </span>v_key = hmac::Key::new(hmac::HMAC_SHA256, key_value.as_ref()); |
| hmac::verify(<span class="kw-2">&</span>v_key, msg.as_bytes(), tag.as_ref())<span class="question-mark">?</span>; |
| </code></pre></div> |
| <h3 id="using-the-multi-part-api"><a href="#using-the-multi-part-api">Using the multi-part API:</a></h3> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>ring::{digest, hmac, rand}; |
| <span class="kw">use </span>ring::rand::SecureRandom; |
| |
| <span class="kw">let </span>parts = [<span class="string">"hello"</span>, <span class="string">", "</span>, <span class="string">"world"</span>]; |
| |
| <span class="comment">// The sender generates a secure key value and signs the message with it. |
| // Note that in a real protocol, a key agreement protocol would be used to |
| // derive `key_value`. |
| </span><span class="kw">let </span>rng = rand::SystemRandom::new(); |
| <span class="kw">let </span><span class="kw-2">mut </span>key_value: [u8; digest::SHA384_OUTPUT_LEN] = rand::generate(<span class="kw-2">&</span>rng)<span class="question-mark">?</span>.expose(); |
| |
| <span class="kw">let </span>s_key = hmac::Key::new(hmac::HMAC_SHA384, key_value.as_ref()); |
| <span class="kw">let </span><span class="kw-2">mut </span>s_ctx = hmac::Context::with_key(<span class="kw-2">&</span>s_key); |
| <span class="kw">for </span>part <span class="kw">in </span><span class="kw-2">&</span>parts { |
| s_ctx.update(part.as_bytes()); |
| } |
| <span class="kw">let </span>tag = s_ctx.sign(); |
| |
| <span class="comment">// The receiver (somehow!) knows the key value, and uses it to verify the |
| // integrity of the message. |
| </span><span class="kw">let </span>v_key = hmac::Key::new(hmac::HMAC_SHA384, key_value.as_ref()); |
| <span class="kw">let </span><span class="kw-2">mut </span>msg = Vec::<u8>::new(); |
| <span class="kw">for </span>part <span class="kw">in </span><span class="kw-2">&</span>parts { |
| msg.extend(part.as_bytes()); |
| } |
| hmac::verify(<span class="kw-2">&</span>v_key, <span class="kw-2">&</span>msg.as_ref(), tag.as_ref())<span class="question-mark">?</span>; |
| </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.Algorithm.html" title="ring::hmac::Algorithm struct">Algorithm</a></div><div class="item-right docblock-short">An HMAC algorithm.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Context.html" title="ring::hmac::Context struct">Context</a></div><div class="item-right docblock-short">A context for multi-step (Init-Update-Finish) HMAC signing.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Key.html" title="ring::hmac::Key struct">Key</a></div><div class="item-right docblock-short">A key to use for HMAC signing.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Tag.html" title="ring::hmac::Tag struct">Tag</a></div><div class="item-right docblock-short">An HMAC tag.</div></div></div><h2 id="statics" class="small-section-header"><a href="#statics">Statics</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="static" href="static.HMAC_SHA1_FOR_LEGACY_USE_ONLY.html" title="ring::hmac::HMAC_SHA1_FOR_LEGACY_USE_ONLY static">HMAC_SHA1_FOR_LEGACY_USE_ONLY</a></div><div class="item-right docblock-short">HMAC using SHA-1. Obsolete.</div></div><div class="item-row"><div class="item-left module-item"><a class="static" href="static.HMAC_SHA256.html" title="ring::hmac::HMAC_SHA256 static">HMAC_SHA256</a></div><div class="item-right docblock-short">HMAC using SHA-256.</div></div><div class="item-row"><div class="item-left module-item"><a class="static" href="static.HMAC_SHA384.html" title="ring::hmac::HMAC_SHA384 static">HMAC_SHA384</a></div><div class="item-right docblock-short">HMAC using SHA-384.</div></div><div class="item-row"><div class="item-left module-item"><a class="static" href="static.HMAC_SHA512.html" title="ring::hmac::HMAC_SHA512 static">HMAC_SHA512</a></div><div class="item-right docblock-short">HMAC using SHA-512.</div></div></div><h2 id="functions" class="small-section-header"><a href="#functions">Functions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.sign.html" title="ring::hmac::sign fn">sign</a></div><div class="item-right docblock-short">Calculates the HMAC of <code>data</code> using the key <code>key</code> in one step.</div></div><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.verify.html" title="ring::hmac::verify fn">verify</a></div><div class="item-right docblock-short">Calculates the HMAC of <code>data</code> using the signing key <code>key</code>, and verifies |
| whether the resultant value equals <code>tag</code>, in one step.</div></div></div><h2 id="types" class="small-section-header"><a href="#types">Type Definitions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="type" href="type.Signature.html" title="ring::hmac::Signature type">Signature</a><span class="stab deprecated" title="">Deprecated</span></div><div class="item-right docblock-short">A deprecated alias for <code>Tag</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="type" href="type.SigningContext.html" title="ring::hmac::SigningContext type">SigningContext</a><span class="stab deprecated" title="">Deprecated</span></div><div class="item-right docblock-short"><code>hmac::SigningContext</code> was renamed to <code>hmac::Context</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="type" href="type.SigningKey.html" title="ring::hmac::SigningKey type">SigningKey</a><span class="stab deprecated" title="">Deprecated</span></div><div class="item-right docblock-short"><code>hmac::SigningKey</code> was renamed to <code>hmac::Key</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="type" href="type.VerificationKey.html" title="ring::hmac::VerificationKey type">VerificationKey</a><span class="stab deprecated" title="">Deprecated</span></div><div class="item-right docblock-short"><code>hmac::VerificationKey</code> was merged into <code>hmac::Key</code>.</div></div></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> |
