| <!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/chacha20_poly1305.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>chacha20_poly1305.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 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="kw">use super</span>::{ |
| chacha::{<span class="self">self</span>, Counter}, |
| iv::Iv, |
| poly1305, Aad, Block, Direction, Nonce, Tag, BLOCK_LEN, |
| }; |
| <span class="kw">use crate</span>::{aead, cpu, endian::<span class="kw-2">*</span>, error, polyfill}; |
| <span class="kw">use </span>core::convert::TryInto; |
| |
| <span class="doccomment">/// ChaCha20-Poly1305 as described in [RFC 7539]. |
| /// |
| /// The keys are 256 bits long and the nonces are 96 bits long. |
| /// |
| /// [RFC 7539]: https://tools.ietf.org/html/rfc7539 |
| </span><span class="kw">pub static </span>CHACHA20_POLY1305: aead::Algorithm = aead::Algorithm { |
| key_len: chacha::KEY_LEN, |
| init: chacha20_poly1305_init, |
| seal: chacha20_poly1305_seal, |
| open: chacha20_poly1305_open, |
| id: aead::AlgorithmID::CHACHA20_POLY1305, |
| max_input_len: <span class="kw">super</span>::max_input_len(<span class="number">64</span>, <span class="number">1</span>), |
| }; |
| |
| <span class="doccomment">/// Copies |key| into |ctx_buf|. |
| </span><span class="kw">fn </span>chacha20_poly1305_init( |
| key: <span class="kw-2">&</span>[u8], |
| _todo: cpu::Features, |
| ) -> <span class="prelude-ty">Result</span><aead::KeyInner, error::Unspecified> { |
| <span class="kw">let </span>key: [u8; chacha::KEY_LEN] = key.try_into()<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(aead::KeyInner::ChaCha20Poly1305(chacha::Key::from(key))) |
| } |
| |
| <span class="kw">fn </span>chacha20_poly1305_seal( |
| key: <span class="kw-2">&</span>aead::KeyInner, |
| nonce: Nonce, |
| aad: Aad<<span class="kw-2">&</span>[u8]>, |
| in_out: <span class="kw-2">&mut </span>[u8], |
| cpu_features: cpu::Features, |
| ) -> Tag { |
| <span class="kw">let </span>key = <span class="kw">match </span>key { |
| aead::KeyInner::ChaCha20Poly1305(key) => key, |
| <span class="kw">_ </span>=> <span class="macro">unreachable!</span>(), |
| }; |
| |
| <span class="attribute">#[cfg(target_arch = <span class="string">"x86_64"</span>)] |
| </span>{ |
| <span class="kw">if </span>cpu::intel::SSE41.available(cpu_features) { |
| <span class="comment">// XXX: BoringSSL uses `alignas(16)` on `key` instead of on the |
| // structure, but Rust can't do that yet; see |
| // https://github.com/rust-lang/rust/issues/73557. |
| // |
| // Keep in sync with the anonymous struct of BoringSSL's |
| // `chacha20_poly1305_seal_data`. |
| </span><span class="attribute">#[repr(align(<span class="number">16</span>), C)] |
| #[derive(Clone, Copy)] |
| </span><span class="kw">struct </span>seal_data_in { |
| key: [u8; chacha::KEY_LEN], |
| counter: u32, |
| nonce: [u8; <span class="kw">super</span>::NONCE_LEN], |
| extra_ciphertext: <span class="kw-2">*const </span>u8, |
| extra_ciphertext_len: usize, |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>data = InOut { |
| input: seal_data_in { |
| key: <span class="kw-2">*</span>key.words_less_safe().as_byte_array(), |
| counter: <span class="number">0</span>, |
| nonce: <span class="kw-2">*</span>nonce.as_ref(), |
| extra_ciphertext: core::ptr::null(), |
| extra_ciphertext_len: <span class="number">0</span>, |
| }, |
| }; |
| |
| <span class="comment">// Encrypts `plaintext_len` bytes from `plaintext` and writes them to `out_ciphertext`. |
| </span><span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">fn </span>GFp_chacha20_poly1305_seal( |
| out_ciphertext: <span class="kw-2">*mut </span>u8, |
| plaintext: <span class="kw-2">*const </span>u8, |
| plaintext_len: usize, |
| ad: <span class="kw-2">*const </span>u8, |
| ad_len: usize, |
| data: <span class="kw-2">&mut </span>InOut<seal_data_in>, |
| ); |
| } |
| |
| <span class="kw">let </span>out = <span class="kw">unsafe </span>{ |
| GFp_chacha20_poly1305_seal( |
| in_out.as_mut_ptr(), |
| in_out.as_ptr(), |
| in_out.len(), |
| aad.as_ref().as_ptr(), |
| aad.as_ref().len(), |
| <span class="kw-2">&mut </span>data, |
| ); |
| <span class="kw-2">&</span>data.out |
| }; |
| |
| <span class="kw">return </span>Tag(out.tag); |
| } |
| } |
| |
| aead(key, nonce, aad, in_out, Direction::Sealing, cpu_features) |
| } |
| |
| <span class="kw">fn </span>chacha20_poly1305_open( |
| key: <span class="kw-2">&</span>aead::KeyInner, |
| nonce: Nonce, |
| aad: Aad<<span class="kw-2">&</span>[u8]>, |
| in_prefix_len: usize, |
| in_out: <span class="kw-2">&mut </span>[u8], |
| cpu_features: cpu::Features, |
| ) -> Tag { |
| <span class="kw">let </span>key = <span class="kw">match </span>key { |
| aead::KeyInner::ChaCha20Poly1305(key) => key, |
| <span class="kw">_ </span>=> <span class="macro">unreachable!</span>(), |
| }; |
| |
| <span class="attribute">#[cfg(target_arch = <span class="string">"x86_64"</span>)] |
| </span>{ |
| <span class="kw">if </span>cpu::intel::SSE41.available(cpu_features) { |
| <span class="comment">// XXX: BoringSSL uses `alignas(16)` on `key` instead of on the |
| // structure, but Rust can't do that yet; see |
| // https://github.com/rust-lang/rust/issues/73557. |
| // |
| // Keep in sync with the anonymous struct of BoringSSL's |
| // `chacha20_poly1305_open_data`. |
| </span><span class="attribute">#[derive(Copy, Clone)] |
| #[repr(align(<span class="number">16</span>), C)] |
| </span><span class="kw">struct </span>open_data_in { |
| key: [u8; chacha::KEY_LEN], |
| counter: u32, |
| nonce: [u8; <span class="kw">super</span>::NONCE_LEN], |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>data = InOut { |
| input: open_data_in { |
| key: <span class="kw-2">*</span>key.words_less_safe().as_byte_array(), |
| counter: <span class="number">0</span>, |
| nonce: <span class="kw-2">*</span>nonce.as_ref(), |
| }, |
| }; |
| |
| <span class="comment">// Decrypts `plaintext_len` bytes from `ciphertext` and writes them to `out_plaintext`. |
| </span><span class="kw">extern </span><span class="string">"C" </span>{ |
| <span class="kw">fn </span>GFp_chacha20_poly1305_open( |
| out_plaintext: <span class="kw-2">*mut </span>u8, |
| ciphertext: <span class="kw-2">*const </span>u8, |
| plaintext_len: usize, |
| ad: <span class="kw-2">*const </span>u8, |
| ad_len: usize, |
| data: <span class="kw-2">&mut </span>InOut<open_data_in>, |
| ); |
| } |
| |
| <span class="kw">let </span>out = <span class="kw">unsafe </span>{ |
| GFp_chacha20_poly1305_open( |
| in_out.as_mut_ptr(), |
| in_out.as_ptr().add(in_prefix_len), |
| in_out.len() - in_prefix_len, |
| aad.as_ref().as_ptr(), |
| aad.as_ref().len(), |
| <span class="kw-2">&mut </span>data, |
| ); |
| <span class="kw-2">&</span>data.out |
| }; |
| |
| <span class="kw">return </span>Tag(out.tag); |
| } |
| } |
| |
| aead( |
| key, |
| nonce, |
| aad, |
| in_out, |
| Direction::Opening { in_prefix_len }, |
| cpu_features, |
| ) |
| } |
| |
| <span class="kw">pub type </span>Key = chacha::Key; |
| |
| <span class="comment">// Keep in sync with BoringSSL's `chacha20_poly1305_open_data` and |
| // `chacha20_poly1305_seal_data`. |
| </span><span class="attribute">#[repr(C)] |
| #[cfg(target_arch = <span class="string">"x86_64"</span>)] |
| </span><span class="kw">union </span>InOut<T> |
| <span class="kw">where |
| </span>T: Copy, |
| { |
| input: T, |
| out: Out, |
| } |
| |
| <span class="comment">// It isn't obvious whether the assembly code works for tags that aren't |
| // 16-byte aligned. In practice it will always be 16-byte aligned because it |
| // is embedded in a union where the other member of the union is 16-byte |
| // aligned. |
| </span><span class="attribute">#[cfg(target_arch = <span class="string">"x86_64"</span>)] |
| #[derive(Clone, Copy)] |
| #[repr(align(<span class="number">16</span>), C)] |
| </span><span class="kw">struct </span>Out { |
| tag: [u8; <span class="kw">super</span>::TAG_LEN], |
| } |
| |
| <span class="attribute">#[inline(always)] </span><span class="comment">// Statically eliminate branches on `direction`. |
| </span><span class="kw">fn </span>aead( |
| chacha20_key: <span class="kw-2">&</span>Key, |
| nonce: Nonce, |
| Aad(aad): Aad<<span class="kw-2">&</span>[u8]>, |
| in_out: <span class="kw-2">&mut </span>[u8], |
| direction: Direction, |
| cpu_features: cpu::Features, |
| ) -> Tag { |
| <span class="kw">let </span><span class="kw-2">mut </span>counter = Counter::zero(nonce); |
| <span class="kw">let </span><span class="kw-2">mut </span>ctx = { |
| <span class="kw">let </span>key = derive_poly1305_key(chacha20_key, counter.increment(), cpu_features); |
| poly1305::Context::from_key(key) |
| }; |
| |
| poly1305_update_padded_16(<span class="kw-2">&mut </span>ctx, aad); |
| |
| <span class="kw">let </span>in_out_len = <span class="kw">match </span>direction { |
| Direction::Opening { in_prefix_len } => { |
| poly1305_update_padded_16(<span class="kw-2">&mut </span>ctx, <span class="kw-2">&</span>in_out[in_prefix_len..]); |
| chacha20_key.encrypt_overlapping(counter, in_out, in_prefix_len); |
| in_out.len() - in_prefix_len |
| } |
| Direction::Sealing => { |
| chacha20_key.encrypt_in_place(counter, in_out); |
| poly1305_update_padded_16(<span class="kw-2">&mut </span>ctx, in_out); |
| in_out.len() |
| } |
| }; |
| |
| ctx.update( |
| Block::from_u64_le( |
| LittleEndian::from(polyfill::u64_from_usize(aad.len())), |
| LittleEndian::from(polyfill::u64_from_usize(in_out_len)), |
| ) |
| .as_ref(), |
| ); |
| ctx.finish() |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>poly1305_update_padded_16(ctx: <span class="kw-2">&mut </span>poly1305::Context, input: <span class="kw-2">&</span>[u8]) { |
| <span class="kw">let </span>remainder_len = input.len() % BLOCK_LEN; |
| <span class="kw">let </span>whole_len = input.len() - remainder_len; |
| <span class="kw">if </span>whole_len > <span class="number">0 </span>{ |
| ctx.update(<span class="kw-2">&</span>input[..whole_len]); |
| } |
| <span class="kw">if </span>remainder_len > <span class="number">0 </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>block = Block::zero(); |
| block.overwrite_part_at(<span class="number">0</span>, <span class="kw-2">&</span>input[whole_len..]); |
| ctx.update(block.as_ref()) |
| } |
| } |
| |
| <span class="comment">// Also used by chacha20_poly1305_openssh. |
| </span><span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">fn </span>derive_poly1305_key( |
| chacha_key: <span class="kw-2">&</span>chacha::Key, |
| iv: Iv, |
| cpu_features: cpu::Features, |
| ) -> poly1305::Key { |
| <span class="kw">let </span><span class="kw-2">mut </span>key_bytes = [<span class="number">0u8</span>; <span class="number">2 </span>* BLOCK_LEN]; |
| chacha_key.encrypt_iv_xor_blocks_in_place(iv, <span class="kw-2">&mut </span>key_bytes); |
| poly1305::Key::new(key_bytes, cpu_features) |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>max_input_len_test() { |
| <span class="comment">// Errata 4858 at https://www.rfc-editor.org/errata_search.php?rfc=7539. |
| </span><span class="macro">assert_eq!</span>(<span class="kw">super</span>::CHACHA20_POLY1305.max_input_len, <span class="number">274_877_906_880u64</span>); |
| } |
| } |
| </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> |
