| <!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/aead/counter.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>counter.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> |
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| </pre><pre class="rust"><code><span class="comment">// Copyright 2018 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="kw">use super</span>::{ |
| iv::{Iv, IV_LEN}, |
| Nonce, |
| }; |
| <span class="kw">use </span><span class="kw">crate</span>::endian::<span class="kw-2">*</span>; |
| <span class="kw">use </span>core::convert::TryInto; |
| |
| <span class="doccomment">/// A generator of a monotonically increasing series of `Iv`s. |
| /// |
| /// Intentionally not `Clone` to ensure counters aren't forked. |
| </span><span class="attribute">#[repr(C)] |
| </span><span class="kw">pub struct </span>Counter<U32> { |
| u32s: [U32; COUNTER_LEN], |
| } |
| |
| <span class="kw">const </span>COUNTER_LEN: usize = <span class="number">4</span>; |
| |
| <span class="kw">impl</span><U32> Counter<U32> |
| <span class="kw">where |
| </span>U32: Copy, |
| U32: Encoding<u32>, |
| U32: From<[u8; <span class="number">4</span>]>, |
| U32: Layout, |
| [U32; <span class="number">4</span>]: ArrayEncoding<[u8; IV_LEN]>, |
| { |
| <span class="kw">pub fn </span>zero(nonce: Nonce) -> <span class="self">Self </span>{ |
| <span class="self">Self</span>::new(nonce, <span class="number">0</span>) |
| } |
| <span class="kw">pub fn </span>one(nonce: Nonce) -> <span class="self">Self </span>{ |
| <span class="self">Self</span>::new(nonce, <span class="number">1</span>) |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">pub fn </span>from_test_vector(nonce: <span class="kw-2">&</span>[u8], initial_counter: u32) -> <span class="self">Self </span>{ |
| <span class="self">Self</span>::new( |
| Nonce::try_assume_unique_for_key(nonce).unwrap(), |
| initial_counter, |
| ) |
| } |
| |
| <span class="kw">fn </span>new(nonce: Nonce, initial_counter: u32) -> <span class="self">Self </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="self">Self </span>{ |
| u32s: [U32::ZERO; COUNTER_LEN], |
| }; |
| <span class="kw">let </span>nonce_index = (U32::COUNTER_INDEX + <span class="number">1</span>) % COUNTER_LEN; |
| (<span class="kw-2">&mut </span>r.u32s[nonce_index..][..<span class="number">3</span>]) |
| .iter_mut() |
| .zip(nonce.as_ref().chunks_exact(<span class="number">4</span>)) |
| .for_each(|(initial, nonce)| { |
| <span class="kw">let </span>nonce: <span class="kw-2">&</span>[u8; <span class="number">4</span>] = nonce.try_into().unwrap(); |
| <span class="kw-2">*</span>initial = U32::from(<span class="kw-2">*</span>nonce); |
| }); |
| r.u32s[U32::COUNTER_INDEX] = U32::from(initial_counter); |
| r |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>increment(<span class="kw-2">&mut </span><span class="self">self</span>) -> Iv { |
| <span class="kw">let </span>current = <span class="self">Self </span>{ u32s: <span class="self">self</span>.u32s }; |
| <span class="self">self</span>.increment_by_less_safe(<span class="number">1</span>); |
| current.into() |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>increment_by_less_safe(<span class="kw-2">&mut </span><span class="self">self</span>, increment_by: u32) { |
| <span class="kw">let </span>counter = <span class="kw-2">&mut </span><span class="self">self</span>.u32s[U32::COUNTER_INDEX]; |
| <span class="kw">let </span>old_value: u32 = (<span class="kw-2">*</span>counter).into(); |
| <span class="kw-2">*</span>counter = U32::from(old_value + increment_by); |
| } |
| } |
| |
| <span class="kw">pub trait </span>Layout { |
| <span class="kw">const </span>COUNTER_INDEX: usize; |
| } |
| |
| <span class="kw">impl </span>Layout <span class="kw">for </span>BigEndian<u32> { |
| <span class="kw">const </span>COUNTER_INDEX: usize = <span class="number">3</span>; |
| } |
| |
| <span class="kw">impl </span>Layout <span class="kw">for </span>LittleEndian<u32> { |
| <span class="kw">const </span>COUNTER_INDEX: usize = <span class="number">0</span>; |
| } |
| |
| <span class="kw">impl</span><U32> Into<Iv> <span class="kw">for </span>Counter<U32> |
| <span class="kw">where |
| </span>[U32; <span class="number">4</span>]: ArrayEncoding<[u8; IV_LEN]>, |
| { |
| <span class="kw">fn </span>into(<span class="self">self</span>) -> Iv { |
| Iv::assume_unique_for_key(<span class="kw-2">*</span><span class="self">self</span>.u32s.as_byte_array()) |
| } |
| } |
| </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> |
