| <!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/rustls-0.19.1/src/prf.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>prf.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="../../rustls/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="../../rustls/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> |
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| </pre><pre class="rust"><code><span class="kw">use </span>ring::digest; |
| <span class="kw">use </span>ring::hmac; |
| |
| <span class="kw">use </span>std::io::Write; |
| |
| <span class="kw">fn </span>convert_digest_to_hmac_alg(hash: <span class="kw-2">&</span><span class="lifetime">'static </span>digest::Algorithm) -> hmac::Algorithm { |
| <span class="kw">if </span>hash == <span class="kw-2">&</span>digest::SHA256 { |
| hmac::HMAC_SHA256 |
| } <span class="kw">else if </span>hash == <span class="kw-2">&</span>digest::SHA384 { |
| hmac::HMAC_SHA384 |
| } <span class="kw">else if </span>hash == <span class="kw-2">&</span>digest::SHA512 { |
| hmac::HMAC_SHA512 |
| } <span class="kw">else </span>{ |
| <span class="macro">panic!</span>(<span class="string">"bad digest for prf"</span>); |
| } |
| } |
| |
| <span class="kw">fn </span>concat_sign(key: <span class="kw-2">&</span>hmac::Key, a: <span class="kw-2">&</span>[u8], b: <span class="kw-2">&</span>[u8]) -> hmac::Tag { |
| <span class="kw">let </span><span class="kw-2">mut </span>ctx = hmac::Context::with_key(key); |
| ctx.update(a); |
| ctx.update(b); |
| ctx.sign() |
| } |
| |
| <span class="kw">fn </span>p(out: <span class="kw-2">&mut </span>[u8], hashalg: <span class="kw-2">&</span><span class="lifetime">'static </span>digest::Algorithm, secret: <span class="kw-2">&</span>[u8], seed: <span class="kw-2">&</span>[u8]) { |
| <span class="kw">let </span>hmac_key = hmac::Key::new(convert_digest_to_hmac_alg(hashalg), secret); |
| |
| <span class="comment">// A(1) |
| </span><span class="kw">let </span><span class="kw-2">mut </span>current_a = hmac::sign(<span class="kw-2">&</span>hmac_key, seed); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>offs = <span class="number">0</span>; |
| |
| <span class="kw">while </span>offs < out.len() { |
| <span class="comment">// P_hash[i] = HMAC_hash(secret, A(i) + seed) |
| </span><span class="kw">let </span>p_term = concat_sign(<span class="kw-2">&</span>hmac_key, current_a.as_ref(), seed); |
| offs += out[offs..] |
| .as_mut() |
| .write(p_term.as_ref()) |
| .unwrap(); |
| |
| <span class="comment">// A(i+1) = HMAC_hash(secret, A(i)) |
| </span>current_a = hmac::sign(<span class="kw-2">&</span>hmac_key, current_a.as_ref()); |
| } |
| } |
| |
| <span class="kw">fn </span>concat(a: <span class="kw-2">&</span>[u8], b: <span class="kw-2">&</span>[u8]) -> Vec<u8> { |
| <span class="kw">let </span><span class="kw-2">mut </span>ret = Vec::new(); |
| ret.extend_from_slice(a); |
| ret.extend_from_slice(b); |
| ret |
| } |
| |
| <span class="kw">pub fn </span>prf( |
| out: <span class="kw-2">&mut </span>[u8], |
| hashalg: <span class="kw-2">&</span><span class="lifetime">'static </span>digest::Algorithm, |
| secret: <span class="kw-2">&</span>[u8], |
| label: <span class="kw-2">&</span>[u8], |
| seed: <span class="kw-2">&</span>[u8], |
| ) { |
| <span class="kw">let </span>joined_seed = concat(label, seed); |
| p(out, hashalg, secret, <span class="kw-2">&</span>joined_seed); |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="kw">use </span>ring::digest::{SHA256, SHA512}; |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>check_sha256() { |
| <span class="kw">let </span>secret = <span class="string">b"\x9b\xbe\x43\x6b\xa9\x40\xf0\x17\xb1\x76\x52\x84\x9a\x71\xdb\x35"</span>; |
| <span class="kw">let </span>seed = <span class="string">b"\xa0\xba\x9f\x93\x6c\xda\x31\x18\x27\xa6\xf7\x96\xff\xd5\x19\x8c"</span>; |
| <span class="kw">let </span>label = <span class="string">b"test label"</span>; |
| <span class="kw">let </span>expect = <span class="macro">include_bytes!</span>(<span class="string">"testdata/prf-result.1.bin"</span>); |
| <span class="kw">let </span><span class="kw-2">mut </span>output = [<span class="number">0u8</span>; <span class="number">100</span>]; |
| |
| <span class="kw">super</span>::prf(<span class="kw-2">&mut </span>output, <span class="kw-2">&</span>SHA256, secret, label, seed); |
| <span class="macro">assert_eq!</span>(expect.len(), output.len()); |
| <span class="macro">assert_eq!</span>(expect.to_vec(), output.to_vec()); |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>check_sha512() { |
| <span class="kw">let </span>secret = <span class="string">b"\xb0\x32\x35\x23\xc1\x85\x35\x99\x58\x4d\x88\x56\x8b\xbb\x05\xeb"</span>; |
| <span class="kw">let </span>seed = <span class="string">b"\xd4\x64\x0e\x12\xe4\xbc\xdb\xfb\x43\x7f\x03\xe6\xae\x41\x8e\xe5"</span>; |
| <span class="kw">let </span>label = <span class="string">b"test label"</span>; |
| <span class="kw">let </span>expect = <span class="macro">include_bytes!</span>(<span class="string">"testdata/prf-result.2.bin"</span>); |
| <span class="kw">let </span><span class="kw-2">mut </span>output = [<span class="number">0u8</span>; <span class="number">196</span>]; |
| |
| <span class="kw">super</span>::prf(<span class="kw-2">&mut </span>output, <span class="kw-2">&</span>SHA512, secret, label, seed); |
| <span class="macro">assert_eq!</span>(expect.len(), output.len()); |
| <span class="macro">assert_eq!</span>(expect.to_vec(), output.to_vec()); |
| } |
| } |
| </code></pre></div> |
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