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</pre><pre class='rust '>
<span class='comment'>// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT</span>
<span class='comment'>// file at the top-level directory of this distribution and at</span>
<span class='comment'>// http://rust-lang.org/COPYRIGHT.</span>
<span class='comment'>//</span>
<span class='comment'>// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span>
<span class='comment'>// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span>
<span class='comment'>// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span>
<span class='comment'>// option. This file may not be copied, modified, or distributed</span>
<span class='comment'>// except according to those terms.</span>
<span class='kw'>use</span> <span class='ident'>std</span>;
<span class='kw'>use</span> <span class='ident'>std</span>::{<span class='ident'>io</span>, <span class='ident'>mem</span>};
<span class='kw'>use</span> <span class='ident'>std</span>::<span class='ident'>ptr</span>;
<span class='kw'>use</span> <span class='ident'>buffer</span>::{<span class='ident'>ReadBuffer</span>, <span class='ident'>WriteBuffer</span>, <span class='ident'>BufferResult</span>};
<span class='kw'>use</span> <span class='ident'>buffer</span>::<span class='ident'>BufferResult</span>::{<span class='ident'>BufferUnderflow</span>, <span class='ident'>BufferOverflow</span>};
<span class='kw'>use</span> <span class='ident'>symmetriccipher</span>::{<span class='ident'>SynchronousStreamCipher</span>, <span class='ident'>SymmetricCipherError</span>};
<span class='doccomment'>/// Write a u64 into a vector, which must be 8 bytes long. The value is written in big-endian</span>
<span class='doccomment'>/// format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>write_u64_be</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u8</span>], <span class='kw-2'>mut</span> <span class='ident'>input</span>: <span class='ident'>u64</span>) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>8</span>);
<span class='ident'>input</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>to_be</span>();
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> <span class='kw-2'>&</span><span class='ident'>input</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span>;
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>tmp</span>, <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>), <span class='number'>8</span>);
}
}
<span class='doccomment'>/// Write a u64 into a vector, which must be 8 bytes long. The value is written in little-endian</span>
<span class='doccomment'>/// format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>write_u64_le</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u8</span>], <span class='kw-2'>mut</span> <span class='ident'>input</span>: <span class='ident'>u64</span>) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>8</span>);
<span class='ident'>input</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>to_le</span>();
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> <span class='kw-2'>&</span><span class='ident'>input</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span>;
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>tmp</span>, <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>), <span class='number'>8</span>);
}
}
<span class='doccomment'>/// Write a vector of u64s into a vector of bytes. The values are written in little-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>write_u64v_le</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u8</span>], <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u64</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>8</span> <span class='op'>*</span> <span class='ident'>input</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>x</span>: <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>y</span>: <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u64</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>);
<span class='kw'>for</span> _ <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>input</span>.<span class='ident'>len</span>() {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> (<span class='kw-2'>*</span><span class='ident'>y</span>).<span class='ident'>to_le</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='kw-2'>&</span><span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span>, <span class='ident'>x</span>, <span class='number'>8</span>);
<span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>x</span>.<span class='ident'>offset</span>(<span class='number'>8</span>);
<span class='ident'>y</span> <span class='op'>=</span> <span class='ident'>y</span>.<span class='ident'>offset</span>(<span class='number'>1</span>);
}
}
}
<span class='doccomment'>/// Write a u32 into a vector, which must be 4 bytes long. The value is written in big-endian</span>
<span class='doccomment'>/// format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>write_u32_be</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> [<span class='ident'>u8</span>], <span class='kw-2'>mut</span> <span class='ident'>input</span>: <span class='ident'>u32</span>) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>4</span>);
<span class='ident'>input</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>to_be</span>();
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> <span class='kw-2'>&</span><span class='ident'>input</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span>;
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>tmp</span>, <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>), <span class='number'>4</span>);
}
}
<span class='doccomment'>/// Write a u32 into a vector, which must be 4 bytes long. The value is written in little-endian</span>
<span class='doccomment'>/// format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>write_u32_le</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u8</span>], <span class='kw-2'>mut</span> <span class='ident'>input</span>: <span class='ident'>u32</span>) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>4</span>);
<span class='ident'>input</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>to_le</span>();
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> <span class='kw-2'>&</span><span class='ident'>input</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span>;
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>tmp</span>, <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>), <span class='number'>4</span>);
}
}
<span class='doccomment'>/// Write a vector of u32s into a vector of bytes. The values are written in little-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>write_u32v_le</span> (<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u8</span>], <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u32</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>4</span> <span class='op'>*</span> <span class='ident'>input</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>x</span>: <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>y</span>: <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>);
<span class='kw'>for</span> _ <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>input</span>.<span class='ident'>len</span>() {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> (<span class='kw-2'>*</span><span class='ident'>y</span>).<span class='ident'>to_le</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='kw-2'>&</span><span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span>, <span class='ident'>x</span>, <span class='number'>4</span>);
<span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>x</span>.<span class='ident'>offset</span>(<span class='number'>4</span>);
<span class='ident'>y</span> <span class='op'>=</span> <span class='ident'>y</span>.<span class='ident'>offset</span>(<span class='number'>1</span>);
}
}
}
<span class='doccomment'>/// Read a vector of bytes into a vector of u64s. The values are read in big-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>read_u64v_be</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u64</span>], <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>*</span> <span class='number'>8</span> <span class='op'>==</span> <span class='ident'>input</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>x</span>: <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u64</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>y</span>: <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>);
<span class='kw'>for</span> _ <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>dst</span>.<span class='ident'>len</span>() {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>tmp</span>: <span class='ident'>u64</span> <span class='op'>=</span> <span class='ident'>mem</span>::<span class='ident'>uninitialized</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>y</span>, <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span>, <span class='number'>8</span>);
<span class='kw-2'>*</span><span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>u64</span>::<span class='ident'>from_be</span>(<span class='ident'>tmp</span>);
<span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>x</span>.<span class='ident'>offset</span>(<span class='number'>1</span>);
<span class='ident'>y</span> <span class='op'>=</span> <span class='ident'>y</span>.<span class='ident'>offset</span>(<span class='number'>8</span>);
}
}
}
<span class='doccomment'>/// Read a vector of bytes into a vector of u64s. The values are read in little-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>read_u64v_le</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u64</span>], <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>*</span> <span class='number'>8</span> <span class='op'>==</span> <span class='ident'>input</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>x</span>: <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u64</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>y</span>: <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>);
<span class='kw'>for</span> _ <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>dst</span>.<span class='ident'>len</span>() {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>tmp</span>: <span class='ident'>u64</span> <span class='op'>=</span> <span class='ident'>mem</span>::<span class='ident'>uninitialized</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>y</span>, <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span>, <span class='number'>8</span>);
<span class='kw-2'>*</span><span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>u64</span>::<span class='ident'>from_le</span>(<span class='ident'>tmp</span>);
<span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>x</span>.<span class='ident'>offset</span>(<span class='number'>1</span>);
<span class='ident'>y</span> <span class='op'>=</span> <span class='ident'>y</span>.<span class='ident'>offset</span>(<span class='number'>8</span>);
}
}
}
<span class='doccomment'>/// Read a vector of bytes into a vector of u32s. The values are read in big-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>read_u32v_be</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u32</span>], <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>*</span> <span class='number'>4</span> <span class='op'>==</span> <span class='ident'>input</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>x</span>: <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>y</span>: <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>);
<span class='kw'>for</span> _ <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>dst</span>.<span class='ident'>len</span>() {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>tmp</span>: <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>mem</span>::<span class='ident'>uninitialized</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>y</span>, <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span>, <span class='number'>4</span>);
<span class='kw-2'>*</span><span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>u32</span>::<span class='ident'>from_be</span>(<span class='ident'>tmp</span>);
<span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>x</span>.<span class='ident'>offset</span>(<span class='number'>1</span>);
<span class='ident'>y</span> <span class='op'>=</span> <span class='ident'>y</span>.<span class='ident'>offset</span>(<span class='number'>4</span>);
}
}
}
<span class='doccomment'>/// Read a vector of bytes into a vector of u32s. The values are read in little-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>read_u32v_le</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u32</span>], <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>*</span> <span class='number'>4</span> <span class='op'>==</span> <span class='ident'>input</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>x</span>: <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>get_unchecked_mut</span>(<span class='number'>0</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>y</span>: <span class='kw-2'>*</span><span class='kw'>const</span> <span class='ident'>u8</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>);
<span class='kw'>for</span> _ <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>dst</span>.<span class='ident'>len</span>() {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>tmp</span>: <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>mem</span>::<span class='ident'>uninitialized</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>y</span>, <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span>, <span class='number'>4</span>);
<span class='kw-2'>*</span><span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>u32</span>::<span class='ident'>from_le</span>(<span class='ident'>tmp</span>);
<span class='ident'>x</span> <span class='op'>=</span> <span class='ident'>x</span>.<span class='ident'>offset</span>(<span class='number'>1</span>);
<span class='ident'>y</span> <span class='op'>=</span> <span class='ident'>y</span>.<span class='ident'>offset</span>(<span class='number'>4</span>);
}
}
}
<span class='doccomment'>/// Read the value of a vector of bytes as a u32 value in little-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>read_u32_le</span>(<span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) <span class='op'>-></span> <span class='ident'>u32</span> {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>input</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>4</span>);
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>tmp</span>: <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>mem</span>::<span class='ident'>uninitialized</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>), <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span>, <span class='number'>4</span>);
<span class='ident'>u32</span>::<span class='ident'>from_le</span>(<span class='ident'>tmp</span>)
}
}
<span class='doccomment'>/// Read the value of a vector of bytes as a u32 value in big-endian format.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>read_u32_be</span>(<span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) <span class='op'>-></span> <span class='ident'>u32</span> {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>input</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>4</span>);
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>tmp</span>: <span class='ident'>u32</span> <span class='op'>=</span> <span class='ident'>mem</span>::<span class='ident'>uninitialized</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>input</span>.<span class='ident'>get_unchecked</span>(<span class='number'>0</span>), <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>tmp</span> <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> _ <span class='kw'>as</span> <span class='kw-2'>*</span><span class='kw-2'>mut</span> <span class='ident'>u8</span>, <span class='number'>4</span>);
<span class='ident'>u32</span>::<span class='ident'>from_be</span>(<span class='ident'>tmp</span>)
}
}
<span class='doccomment'>/// XOR plaintext and keystream, storing the result in dst.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>xor_keystream</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span>[<span class='ident'>u8</span>], <span class='ident'>plaintext</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>], <span class='ident'>keystream</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='ident'>plaintext</span>.<span class='ident'>len</span>());
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>plaintext</span>.<span class='ident'>len</span>() <span class='op'><=</span> <span class='ident'>keystream</span>.<span class='ident'>len</span>());
<span class='comment'>// Do one byte at a time, using unsafe to skip bounds checking.</span>
<span class='kw'>let</span> <span class='ident'>p</span> <span class='op'>=</span> <span class='ident'>plaintext</span>.<span class='ident'>as_ptr</span>();
<span class='kw'>let</span> <span class='ident'>k</span> <span class='op'>=</span> <span class='ident'>keystream</span>.<span class='ident'>as_ptr</span>();
<span class='kw'>let</span> <span class='ident'>d</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>as_mut_ptr</span>();
<span class='kw'>for</span> <span class='ident'>i</span> <span class='kw'>in</span> <span class='number'>0isize</span>..<span class='ident'>plaintext</span>.<span class='ident'>len</span>() <span class='kw'>as</span> <span class='ident'>isize</span> {
<span class='kw'>unsafe</span>{ <span class='kw-2'>*</span><span class='ident'>d</span>.<span class='ident'>offset</span>(<span class='ident'>i</span>) <span class='op'>=</span> <span class='kw-2'>*</span><span class='ident'>p</span>.<span class='ident'>offset</span>(<span class='ident'>i</span>) <span class='op'>^</span> <span class='kw-2'>*</span><span class='ident'>k</span>.<span class='ident'>offset</span>(<span class='ident'>i</span>) };
}
}
<span class='doccomment'>/// Copy bytes from src to dest</span>
<span class='attribute'>#[<span class='ident'>inline</span>]</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>copy_memory</span>(<span class='ident'>src</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>], <span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> [<span class='ident'>u8</span>]) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>dst</span>.<span class='ident'>len</span>() <span class='op'>>=</span> <span class='ident'>src</span>.<span class='ident'>len</span>());
<span class='kw'>unsafe</span> {
<span class='kw'>let</span> <span class='ident'>srcp</span> <span class='op'>=</span> <span class='ident'>src</span>.<span class='ident'>as_ptr</span>();
<span class='kw'>let</span> <span class='ident'>dstp</span> <span class='op'>=</span> <span class='ident'>dst</span>.<span class='ident'>as_mut_ptr</span>();
<span class='ident'>ptr</span>::<span class='ident'>copy_nonoverlapping</span>(<span class='ident'>srcp</span>, <span class='ident'>dstp</span>, <span class='ident'>src</span>.<span class='ident'>len</span>());
}
}
<span class='doccomment'>/// Zero all bytes in dst</span>
<span class='attribute'>#[<span class='ident'>inline</span>]</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>zero</span>(<span class='ident'>dst</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> [<span class='ident'>u8</span>]) {
<span class='kw'>unsafe</span> {
<span class='ident'>ptr</span>::<span class='ident'>write_bytes</span>(<span class='ident'>dst</span>.<span class='ident'>as_mut_ptr</span>(), <span class='number'>0</span>, <span class='ident'>dst</span>.<span class='ident'>len</span>());
}
}
<span class='doccomment'>/// An extension trait to implement a few useful serialization</span>
<span class='doccomment'>/// methods on types that implement Write</span>
<span class='kw'>pub</span> <span class='kw'>trait</span> <span class='ident'>WriteExt</span> {
<span class='kw'>fn</span> <span class='ident'>write_u8</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u8</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span>;
<span class='kw'>fn</span> <span class='ident'>write_u32_le</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u32</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span>;
<span class='kw'>fn</span> <span class='ident'>write_u32_be</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u32</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span>;
<span class='kw'>fn</span> <span class='ident'>write_u64_le</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u64</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span>;
<span class='kw'>fn</span> <span class='ident'>write_u64_be</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u64</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span>;
}
<span class='kw'>impl</span> <span class='op'><</span><span class='ident'>T</span><span class='op'>></span> <span class='ident'>WriteExt</span> <span class='kw'>for</span> <span class='ident'>T</span> <span class='kw'>where</span> <span class='ident'>T</span>: <span class='ident'>io</span>::<span class='ident'>Write</span> {
<span class='kw'>fn</span> <span class='ident'>write_u8</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u8</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span> {
<span class='kw'>let</span> <span class='ident'>buff</span> <span class='op'>=</span> [<span class='ident'>val</span>];
<span class='self'>self</span>.<span class='ident'>write_all</span>(<span class='kw-2'>&</span><span class='ident'>buff</span>)
}
<span class='kw'>fn</span> <span class='ident'>write_u32_le</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u32</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>buff</span> <span class='op'>=</span> [<span class='number'>0u8</span>; <span class='number'>4</span>];
<span class='ident'>write_u32_le</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>buff</span>, <span class='ident'>val</span>);
<span class='self'>self</span>.<span class='ident'>write_all</span>(<span class='kw-2'>&</span><span class='ident'>buff</span>)
}
<span class='kw'>fn</span> <span class='ident'>write_u32_be</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u32</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>buff</span> <span class='op'>=</span> [<span class='number'>0u8</span>; <span class='number'>4</span>];
<span class='ident'>write_u32_be</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>buff</span>, <span class='ident'>val</span>);
<span class='self'>self</span>.<span class='ident'>write_all</span>(<span class='kw-2'>&</span><span class='ident'>buff</span>)
}
<span class='kw'>fn</span> <span class='ident'>write_u64_le</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u64</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>buff</span> <span class='op'>=</span> [<span class='number'>0u8</span>; <span class='number'>8</span>];
<span class='ident'>write_u64_le</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>buff</span>, <span class='ident'>val</span>);
<span class='self'>self</span>.<span class='ident'>write_all</span>(<span class='kw-2'>&</span><span class='ident'>buff</span>)
}
<span class='kw'>fn</span> <span class='ident'>write_u64_be</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>val</span>: <span class='ident'>u64</span>) <span class='op'>-></span> <span class='ident'>io</span>::<span class='prelude-ty'>Result</span><span class='op'><</span>()<span class='op'>></span> {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>buff</span> <span class='op'>=</span> [<span class='number'>0u8</span>; <span class='number'>8</span>];
<span class='ident'>write_u64_be</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>buff</span>, <span class='ident'>val</span>);
<span class='self'>self</span>.<span class='ident'>write_all</span>(<span class='kw-2'>&</span><span class='ident'>buff</span>)
}
}
<span class='doccomment'>/// symm_enc_or_dec() implements the necessary functionality to turn a SynchronousStreamCipher into</span>
<span class='doccomment'>/// an Encryptor or Decryptor</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>symm_enc_or_dec</span><span class='op'><</span><span class='ident'>S</span>: <span class='ident'>SynchronousStreamCipher</span>, <span class='ident'>R</span>: <span class='ident'>ReadBuffer</span>, <span class='ident'>W</span>: <span class='ident'>WriteBuffer</span><span class='op'>></span>(
<span class='ident'>c</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>S</span>,
<span class='ident'>input</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>R</span>,
<span class='ident'>output</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>W</span>) <span class='op'>-></span>
<span class='prelude-ty'>Result</span><span class='op'><</span><span class='ident'>BufferResult</span>, <span class='ident'>SymmetricCipherError</span><span class='op'>></span> {
<span class='kw'>let</span> <span class='ident'>count</span> <span class='op'>=</span> <span class='ident'>std</span>::<span class='ident'>cmp</span>::<span class='ident'>min</span>(<span class='ident'>input</span>.<span class='ident'>remaining</span>(), <span class='ident'>output</span>.<span class='ident'>remaining</span>());
<span class='ident'>c</span>.<span class='ident'>process</span>(<span class='ident'>input</span>.<span class='ident'>take_next</span>(<span class='ident'>count</span>), <span class='ident'>output</span>.<span class='ident'>take_next</span>(<span class='ident'>count</span>));
<span class='kw'>if</span> <span class='ident'>input</span>.<span class='ident'>is_empty</span>() {
<span class='prelude-val'>Ok</span>(<span class='ident'>BufferUnderflow</span>)
} <span class='kw'>else</span> {
<span class='prelude-val'>Ok</span>(<span class='ident'>BufferOverflow</span>)
}
}
<span class='doccomment'>/// Convert the value in bytes to the number of bits, a tuple where the 1st item is the</span>
<span class='doccomment'>/// high-order value and the 2nd item is the low order value.</span>
<span class='kw'>fn</span> <span class='ident'>to_bits</span>(<span class='ident'>x</span>: <span class='ident'>u64</span>) <span class='op'>-></span> (<span class='ident'>u64</span>, <span class='ident'>u64</span>) {
(<span class='ident'>x</span> <span class='op'>>></span> <span class='number'>61</span>, <span class='ident'>x</span> <span class='op'><<</span> <span class='number'>3</span>)
}
<span class='doccomment'>/// Adds the specified number of bytes to the bit count. panic!() if this would cause numeric</span>
<span class='doccomment'>/// overflow.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>add_bytes_to_bits</span>(<span class='ident'>bits</span>: <span class='ident'>u64</span>, <span class='ident'>bytes</span>: <span class='ident'>u64</span>) <span class='op'>-></span> <span class='ident'>u64</span> {
<span class='kw'>let</span> (<span class='ident'>new_high_bits</span>, <span class='ident'>new_low_bits</span>) <span class='op'>=</span> <span class='ident'>to_bits</span>(<span class='ident'>bytes</span>);
<span class='kw'>if</span> <span class='ident'>new_high_bits</span> <span class='op'>></span> <span class='number'>0</span> {
<span class='macro'>panic</span><span class='macro'>!</span>(<span class='string'>"Numeric overflow occured."</span>)
}
<span class='ident'>bits</span>.<span class='ident'>checked_add</span>(<span class='ident'>new_low_bits</span>).<span class='ident'>expect</span>(<span class='string'>"Numeric overflow occured."</span>)
}
<span class='doccomment'>/// Adds the specified number of bytes to the bit count, which is a tuple where the first element is</span>
<span class='doccomment'>/// the high order value. panic!() if this would cause numeric overflow.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>add_bytes_to_bits_tuple</span>
(<span class='ident'>bits</span>: (<span class='ident'>u64</span>, <span class='ident'>u64</span>), <span class='ident'>bytes</span>: <span class='ident'>u64</span>) <span class='op'>-></span> (<span class='ident'>u64</span>, <span class='ident'>u64</span>) {
<span class='kw'>let</span> (<span class='ident'>new_high_bits</span>, <span class='ident'>new_low_bits</span>) <span class='op'>=</span> <span class='ident'>to_bits</span>(<span class='ident'>bytes</span>);
<span class='kw'>let</span> (<span class='ident'>hi</span>, <span class='ident'>low</span>) <span class='op'>=</span> <span class='ident'>bits</span>;
<span class='comment'>// Add the low order value - if there is no overflow, then add the high order values</span>
<span class='comment'>// If the addition of the low order values causes overflow, add one to the high order values</span>
<span class='comment'>// before adding them.</span>
<span class='kw'>match</span> <span class='ident'>low</span>.<span class='ident'>checked_add</span>(<span class='ident'>new_low_bits</span>) {
<span class='prelude-val'>Some</span>(<span class='ident'>x</span>) <span class='op'>=></span> {
<span class='kw'>if</span> <span class='ident'>new_high_bits</span> <span class='op'>==</span> <span class='number'>0</span> {
<span class='comment'>// This is the fast path - every other alternative will rarely occur in practice</span>
<span class='comment'>// considering how large an input would need to be for those paths to be used.</span>
<span class='kw'>return</span> (<span class='ident'>hi</span>, <span class='ident'>x</span>);
} <span class='kw'>else</span> {
<span class='kw'>match</span> <span class='ident'>hi</span>.<span class='ident'>checked_add</span>(<span class='ident'>new_high_bits</span>) {
<span class='prelude-val'>Some</span>(<span class='ident'>y</span>) <span class='op'>=></span> <span class='kw'>return</span> (<span class='ident'>y</span>, <span class='ident'>x</span>),
<span class='prelude-val'>None</span> <span class='op'>=></span> <span class='macro'>panic</span><span class='macro'>!</span>(<span class='string'>"Numeric overflow occured."</span>)
}
}
},
<span class='prelude-val'>None</span> <span class='op'>=></span> {
<span class='kw'>let</span> <span class='ident'>z</span> <span class='op'>=</span> <span class='kw'>match</span> <span class='ident'>new_high_bits</span>.<span class='ident'>checked_add</span>(<span class='number'>1</span>) {
<span class='prelude-val'>Some</span>(<span class='ident'>w</span>) <span class='op'>=></span> <span class='ident'>w</span>,
<span class='prelude-val'>None</span> <span class='op'>=></span> <span class='macro'>panic</span><span class='macro'>!</span>(<span class='string'>"Numeric overflow occured."</span>)
};
<span class='kw'>match</span> <span class='ident'>hi</span>.<span class='ident'>checked_add</span>(<span class='ident'>z</span>) {
<span class='comment'>// This re-executes the addition that was already performed earlier when overflow</span>
<span class='comment'>// occured, this time allowing the overflow to happen. Technically, this could be</span>
<span class='comment'>// avoided by using the checked add intrinsic directly, but that involves using</span>
<span class='comment'>// unsafe code and is not really worthwhile considering how infrequently code will</span>
<span class='comment'>// run in practice. This is the reason that this function requires that the type T</span>
<span class='comment'>// be UnsignedInt - overflow is not defined for Signed types. This function could</span>
<span class='comment'>// be implemented for signed types as well if that were needed.</span>
<span class='prelude-val'>Some</span>(<span class='ident'>y</span>) <span class='op'>=></span> <span class='kw'>return</span> (<span class='ident'>y</span>, <span class='ident'>low</span>.<span class='ident'>wrapping_add</span>(<span class='ident'>new_low_bits</span>)),
<span class='prelude-val'>None</span> <span class='op'>=></span> <span class='macro'>panic</span><span class='macro'>!</span>(<span class='string'>"Numeric overflow occured."</span>)
}
}
}
}
<span class='doccomment'>/// A FixedBuffer, likes its name implies, is a fixed size buffer. When the buffer becomes full, it</span>
<span class='doccomment'>/// must be processed. The input() method takes care of processing and then clearing the buffer</span>
<span class='doccomment'>/// automatically. However, other methods do not and require the caller to process the buffer. Any</span>
<span class='doccomment'>/// method that modifies the buffer directory or provides the caller with bytes that can be modifies</span>
<span class='doccomment'>/// results in those bytes being marked as used by the buffer.</span>
<span class='kw'>pub</span> <span class='kw'>trait</span> <span class='ident'>FixedBuffer</span> {
<span class='doccomment'>/// Input a vector of bytes. If the buffer becomes full, process it with the provided</span>
<span class='doccomment'>/// function and then clear the buffer.</span>
<span class='kw'>fn</span> <span class='ident'>input</span><span class='op'><</span><span class='ident'>F</span>: <span class='ident'>FnMut</span>(<span class='kw-2'>&</span>[<span class='ident'>u8</span>])<span class='op'>></span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>], <span class='ident'>func</span>: <span class='ident'>F</span>);
<span class='doccomment'>/// Reset the buffer.</span>
<span class='kw'>fn</span> <span class='ident'>reset</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>);
<span class='doccomment'>/// Zero the buffer up until the specified index. The buffer position currently must not be</span>
<span class='doccomment'>/// greater than that index.</span>
<span class='kw'>fn</span> <span class='ident'>zero_until</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>idx</span>: <span class='ident'>usize</span>);
<span class='doccomment'>/// Get a slice of the buffer of the specified size. There must be at least that many bytes</span>
<span class='doccomment'>/// remaining in the buffer.</span>
<span class='kw'>fn</span> <span class='ident'>next</span><span class='op'><</span><span class='lifetime'>'s</span><span class='op'>></span>(<span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>len</span>: <span class='ident'>usize</span>) <span class='op'>-></span> <span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> [<span class='ident'>u8</span>];
<span class='doccomment'>/// Get the current buffer. The buffer must already be full. This clears the buffer as well.</span>
<span class='kw'>fn</span> <span class='ident'>full_buffer</span><span class='op'><</span><span class='lifetime'>'s</span><span class='op'>></span>(<span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> <span class='self'>self</span>) <span class='op'>-></span> <span class='kw-2'>&</span><span class='lifetime'>'s</span> [<span class='ident'>u8</span>];
<span class='doccomment'>/// Get the current buffer.</span>
<span class='kw'>fn</span> <span class='ident'>current_buffer</span><span class='op'><</span><span class='lifetime'>'s</span><span class='op'>></span>(<span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> <span class='self'>self</span>) <span class='op'>-></span> <span class='kw-2'>&</span><span class='lifetime'>'s</span> [<span class='ident'>u8</span>];
<span class='doccomment'>/// Get the current position of the buffer.</span>
<span class='kw'>fn</span> <span class='ident'>position</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span>;
<span class='doccomment'>/// Get the number of bytes remaining in the buffer until it is full.</span>
<span class='kw'>fn</span> <span class='ident'>remaining</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span>;
<span class='doccomment'>/// Get the size of the buffer</span>
<span class='kw'>fn</span> <span class='ident'>size</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span>;
}
<span class='macro'>macro_rules</span><span class='macro'>!</span> <span class='ident'>impl_fixed_buffer</span>( (<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>name</span>:<span class='ident'>ident</span>, <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>size</span>:<span class='ident'>expr</span>) <span class='op'>=></span> (
<span class='kw'>impl</span> <span class='ident'>FixedBuffer</span> <span class='kw'>for</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>name</span> {
<span class='kw'>fn</span> <span class='ident'>input</span><span class='op'><</span><span class='ident'>F</span>: <span class='ident'>FnMut</span>(<span class='kw-2'>&</span>[<span class='ident'>u8</span>])<span class='op'>></span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>input</span>: <span class='kw-2'>&</span>[<span class='ident'>u8</span>], <span class='kw-2'>mut</span> <span class='ident'>func</span>: <span class='ident'>F</span>) {
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>i</span> <span class='op'>=</span> <span class='number'>0</span>;
<span class='comment'>// FIXME: #6304 - This local variable shouldn't be necessary.</span>
<span class='kw'>let</span> <span class='ident'>size</span> <span class='op'>=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>size</span>;
<span class='comment'>// If there is already data in the buffer, copy as much as we can into it and process</span>
<span class='comment'>// the data if the buffer becomes full.</span>
<span class='kw'>if</span> <span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>!=</span> <span class='number'>0</span> {
<span class='kw'>let</span> <span class='ident'>buffer_remaining</span> <span class='op'>=</span> <span class='ident'>size</span> <span class='op'>-</span> <span class='self'>self</span>.<span class='ident'>buffer_idx</span>;
<span class='kw'>if</span> <span class='ident'>input</span>.<span class='ident'>len</span>() <span class='op'>>=</span> <span class='ident'>buffer_remaining</span> {
<span class='ident'>copy_memory</span>(
<span class='kw-2'>&</span><span class='ident'>input</span>[..<span class='ident'>buffer_remaining</span>],
<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>.<span class='ident'>buffer</span>[<span class='self'>self</span>.<span class='ident'>buffer_idx</span>..<span class='ident'>size</span>]);
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>=</span> <span class='number'>0</span>;
<span class='ident'>func</span>(<span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>buffer</span>);
<span class='ident'>i</span> <span class='op'>+=</span> <span class='ident'>buffer_remaining</span>;
} <span class='kw'>else</span> {
<span class='ident'>copy_memory</span>(
<span class='ident'>input</span>,
<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>.<span class='ident'>buffer</span>[<span class='self'>self</span>.<span class='ident'>buffer_idx</span>..<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>+</span> <span class='ident'>input</span>.<span class='ident'>len</span>()]);
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>+=</span> <span class='ident'>input</span>.<span class='ident'>len</span>();
<span class='kw'>return</span>;
}
}
<span class='comment'>// While we have at least a full buffer size chunks's worth of data, process that data</span>
<span class='comment'>// without copying it into the buffer</span>
<span class='kw'>while</span> <span class='ident'>input</span>.<span class='ident'>len</span>() <span class='op'>-</span> <span class='ident'>i</span> <span class='op'>>=</span> <span class='ident'>size</span> {
<span class='ident'>func</span>(<span class='kw-2'>&</span><span class='ident'>input</span>[<span class='ident'>i</span>..<span class='ident'>i</span> <span class='op'>+</span> <span class='ident'>size</span>]);
<span class='ident'>i</span> <span class='op'>+=</span> <span class='ident'>size</span>;
}
<span class='comment'>// Copy any input data into the buffer. At this point in the method, the ammount of</span>
<span class='comment'>// data left in the input vector will be less than the buffer size and the buffer will</span>
<span class='comment'>// be empty.</span>
<span class='kw'>let</span> <span class='ident'>input_remaining</span> <span class='op'>=</span> <span class='ident'>input</span>.<span class='ident'>len</span>() <span class='op'>-</span> <span class='ident'>i</span>;
<span class='ident'>copy_memory</span>(
<span class='kw-2'>&</span><span class='ident'>input</span>[<span class='ident'>i</span>..],
<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>.<span class='ident'>buffer</span>[<span class='number'>0</span>..<span class='ident'>input_remaining</span>]);
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>+=</span> <span class='ident'>input_remaining</span>;
}
<span class='kw'>fn</span> <span class='ident'>reset</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>) {
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>=</span> <span class='number'>0</span>;
}
<span class='kw'>fn</span> <span class='ident'>zero_until</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>idx</span>: <span class='ident'>usize</span>) {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>idx</span> <span class='op'>>=</span> <span class='self'>self</span>.<span class='ident'>buffer_idx</span>);
<span class='ident'>zero</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>.<span class='ident'>buffer</span>[<span class='self'>self</span>.<span class='ident'>buffer_idx</span>..<span class='ident'>idx</span>]);
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>=</span> <span class='ident'>idx</span>;
}
<span class='kw'>fn</span> <span class='ident'>next</span><span class='op'><</span><span class='lifetime'>'s</span><span class='op'>></span>(<span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>len</span>: <span class='ident'>usize</span>) <span class='op'>-></span> <span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> [<span class='ident'>u8</span>] {
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>+=</span> <span class='ident'>len</span>;
<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>.<span class='ident'>buffer</span>[<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>-</span> <span class='ident'>len</span>..<span class='self'>self</span>.<span class='ident'>buffer_idx</span>]
}
<span class='kw'>fn</span> <span class='ident'>full_buffer</span><span class='op'><</span><span class='lifetime'>'s</span><span class='op'>></span>(<span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> <span class='self'>self</span>) <span class='op'>-></span> <span class='kw-2'>&</span><span class='lifetime'>'s</span> [<span class='ident'>u8</span>] {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>==</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>size</span>);
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>=</span> <span class='number'>0</span>;
<span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>buffer</span>[..<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>size</span>]
}
<span class='kw'>fn</span> <span class='ident'>current_buffer</span><span class='op'><</span><span class='lifetime'>'s</span><span class='op'>></span>(<span class='kw-2'>&</span><span class='lifetime'>'s</span> <span class='kw-2'>mut</span> <span class='self'>self</span>) <span class='op'>-></span> <span class='kw-2'>&</span><span class='lifetime'>'s</span> [<span class='ident'>u8</span>] {
<span class='kw'>let</span> <span class='ident'>tmp</span> <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>buffer_idx</span>;
<span class='self'>self</span>.<span class='ident'>buffer_idx</span> <span class='op'>=</span> <span class='number'>0</span>;
<span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>buffer</span>[..<span class='ident'>tmp</span>]
}
<span class='kw'>fn</span> <span class='ident'>position</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span> { <span class='self'>self</span>.<span class='ident'>buffer_idx</span> }
<span class='kw'>fn</span> <span class='ident'>remaining</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span> { <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>size</span> <span class='op'>-</span> <span class='self'>self</span>.<span class='ident'>buffer_idx</span> }
<span class='kw'>fn</span> <span class='ident'>size</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span> { <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>size</span> }
}
));
<span class='doccomment'>/// A fixed size buffer of 64 bytes useful for cryptographic operations.</span>
<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Copy</span>)]</span>
<span class='kw'>pub</span> <span class='kw'>struct</span> <span class='ident'>FixedBuffer64</span> {
<span class='ident'>buffer</span>: [<span class='ident'>u8</span>; <span class='number'>64</span>],
<span class='ident'>buffer_idx</span>: <span class='ident'>usize</span>,
}
<span class='kw'>impl</span> <span class='ident'>Clone</span> <span class='kw'>for</span> <span class='ident'>FixedBuffer64</span> { <span class='kw'>fn</span> <span class='ident'>clone</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>FixedBuffer64</span> { <span class='kw-2'>*</span><span class='self'>self</span> } }
<span class='kw'>impl</span> <span class='ident'>FixedBuffer64</span> {
<span class='doccomment'>/// Create a new buffer</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>new</span>() <span class='op'>-></span> <span class='ident'>FixedBuffer64</span> {
<span class='ident'>FixedBuffer64</span> {
<span class='ident'>buffer</span>: [<span class='number'>0u8</span>; <span class='number'>64</span>],
<span class='ident'>buffer_idx</span>: <span class='number'>0</span>
}
}
}
<span class='macro'>impl_fixed_buffer</span><span class='macro'>!</span>(<span class='ident'>FixedBuffer64</span>, <span class='number'>64</span>);
<span class='doccomment'>/// A fixed size buffer of 128 bytes useful for cryptographic operations.</span>
<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Copy</span>)]</span>
<span class='kw'>pub</span> <span class='kw'>struct</span> <span class='ident'>FixedBuffer128</span> {
<span class='ident'>buffer</span>: [<span class='ident'>u8</span>; <span class='number'>128</span>],
<span class='ident'>buffer_idx</span>: <span class='ident'>usize</span>,
}
<span class='kw'>impl</span> <span class='ident'>Clone</span> <span class='kw'>for</span> <span class='ident'>FixedBuffer128</span> { <span class='kw'>fn</span> <span class='ident'>clone</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>FixedBuffer128</span> { <span class='kw-2'>*</span><span class='self'>self</span> } }
<span class='kw'>impl</span> <span class='ident'>FixedBuffer128</span> {
<span class='doccomment'>/// Create a new buffer</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>new</span>() <span class='op'>-></span> <span class='ident'>FixedBuffer128</span> {
<span class='ident'>FixedBuffer128</span> {
<span class='ident'>buffer</span>: [<span class='number'>0u8</span>; <span class='number'>128</span>],
<span class='ident'>buffer_idx</span>: <span class='number'>0</span>
}
}
}
<span class='macro'>impl_fixed_buffer</span><span class='macro'>!</span>(<span class='ident'>FixedBuffer128</span>, <span class='number'>128</span>);
<span class='doccomment'>/// The StandardPadding trait adds a method useful for various hash algorithms to a FixedBuffer</span>
<span class='doccomment'>/// struct.</span>
<span class='kw'>pub</span> <span class='kw'>trait</span> <span class='ident'>StandardPadding</span> {
<span class='doccomment'>/// Add standard padding to the buffer. The buffer must not be full when this method is called</span>
<span class='doccomment'>/// and is guaranteed to have exactly rem remaining bytes when it returns. If there are not at</span>
<span class='doccomment'>/// least rem bytes available, the buffer will be zero padded, processed, cleared, and then</span>
<span class='doccomment'>/// filled with zeros again until only rem bytes are remaining.</span>
<span class='kw'>fn</span> <span class='ident'>standard_padding</span><span class='op'><</span><span class='ident'>F</span>: <span class='ident'>FnMut</span>(<span class='kw-2'>&</span>[<span class='ident'>u8</span>])<span class='op'>></span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>rem</span>: <span class='ident'>usize</span>, <span class='ident'>func</span>: <span class='ident'>F</span>);
}
<span class='kw'>impl</span> <span class='op'><</span><span class='ident'>T</span>: <span class='ident'>FixedBuffer</span><span class='op'>></span> <span class='ident'>StandardPadding</span> <span class='kw'>for</span> <span class='ident'>T</span> {
<span class='kw'>fn</span> <span class='ident'>standard_padding</span><span class='op'><</span><span class='ident'>F</span>: <span class='ident'>FnMut</span>(<span class='kw-2'>&</span>[<span class='ident'>u8</span>])<span class='op'>></span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>, <span class='ident'>rem</span>: <span class='ident'>usize</span>, <span class='kw-2'>mut</span> <span class='ident'>func</span>: <span class='ident'>F</span>) {
<span class='kw'>let</span> <span class='ident'>size</span> <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>size</span>();
<span class='self'>self</span>.<span class='ident'>next</span>(<span class='number'>1</span>)[<span class='number'>0</span>] <span class='op'>=</span> <span class='number'>128</span>;
<span class='kw'>if</span> <span class='self'>self</span>.<span class='ident'>remaining</span>() <span class='op'><</span> <span class='ident'>rem</span> {
<span class='self'>self</span>.<span class='ident'>zero_until</span>(<span class='ident'>size</span>);
<span class='ident'>func</span>(<span class='self'>self</span>.<span class='ident'>full_buffer</span>());
}
<span class='self'>self</span>.<span class='ident'>zero_until</span>(<span class='ident'>size</span> <span class='op'>-</span> <span class='ident'>rem</span>);
}
}
<span class='attribute'>#[<span class='ident'>cfg</span>(<span class='ident'>test</span>)]</span>
<span class='kw'>pub</span> <span class='kw'>mod</span> <span class='ident'>test</span> {
<span class='kw'>use</span> <span class='ident'>std</span>;
<span class='kw'>use</span> <span class='ident'>std</span>::<span class='ident'>iter</span>::<span class='ident'>repeat</span>;
<span class='kw'>use</span> <span class='ident'>rand</span>::<span class='ident'>IsaacRng</span>;
<span class='kw'>use</span> <span class='ident'>rand</span>::<span class='ident'>distributions</span>::{<span class='ident'>IndependentSample</span>, <span class='ident'>Range</span>};
<span class='kw'>use</span> <span class='ident'>cryptoutil</span>::{<span class='ident'>add_bytes_to_bits</span>, <span class='ident'>add_bytes_to_bits_tuple</span>};
<span class='kw'>use</span> <span class='ident'>digest</span>::<span class='ident'>Digest</span>;
<span class='doccomment'>/// Feed 1,000,000 'a's into the digest with varying input sizes and check that the result is</span>
<span class='doccomment'>/// correct.</span>
<span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>test_digest_1million_random</span><span class='op'><</span><span class='ident'>D</span>: <span class='ident'>Digest</span><span class='op'>></span>(<span class='ident'>digest</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>D</span>, <span class='ident'>blocksize</span>: <span class='ident'>usize</span>, <span class='ident'>expected</span>: <span class='kw-2'>&</span><span class='ident'>str</span>) {
<span class='kw'>let</span> <span class='ident'>total_size</span> <span class='op'>=</span> <span class='number'>1000000</span>;
<span class='kw'>let</span> <span class='ident'>buffer</span>: <span class='ident'>Vec</span><span class='op'><</span><span class='ident'>u8</span><span class='op'>></span> <span class='op'>=</span> <span class='ident'>repeat</span>(<span class='string'>'a'</span> <span class='kw'>as</span> <span class='ident'>u8</span>).<span class='ident'>take</span>(<span class='ident'>blocksize</span> <span class='op'>*</span> <span class='number'>2</span>).<span class='ident'>collect</span>();
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>rng</span> <span class='op'>=</span> <span class='ident'>IsaacRng</span>::<span class='ident'>new_unseeded</span>();
<span class='kw'>let</span> <span class='ident'>range</span> <span class='op'>=</span> <span class='ident'>Range</span>::<span class='ident'>new</span>(<span class='number'>0</span>, <span class='number'>2</span> <span class='op'>*</span> <span class='ident'>blocksize</span> <span class='op'>+</span> <span class='number'>1</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>count</span> <span class='op'>=</span> <span class='number'>0</span>;
<span class='ident'>digest</span>.<span class='ident'>reset</span>();
<span class='kw'>while</span> <span class='ident'>count</span> <span class='op'><</span> <span class='ident'>total_size</span> {
<span class='kw'>let</span> <span class='ident'>next</span> <span class='op'>=</span> <span class='ident'>range</span>.<span class='ident'>ind_sample</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>rng</span>);
<span class='kw'>let</span> <span class='ident'>remaining</span> <span class='op'>=</span> <span class='ident'>total_size</span> <span class='op'>-</span> <span class='ident'>count</span>;
<span class='kw'>let</span> <span class='ident'>size</span> <span class='op'>=</span> <span class='kw'>if</span> <span class='ident'>next</span> <span class='op'>></span> <span class='ident'>remaining</span> { <span class='ident'>remaining</span> } <span class='kw'>else</span> { <span class='ident'>next</span> };
<span class='ident'>digest</span>.<span class='ident'>input</span>(<span class='kw-2'>&</span><span class='ident'>buffer</span>[..<span class='ident'>size</span>]);
<span class='ident'>count</span> <span class='op'>+=</span> <span class='ident'>size</span>;
}
<span class='kw'>let</span> <span class='ident'>result_str</span> <span class='op'>=</span> <span class='ident'>digest</span>.<span class='ident'>result_str</span>();
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>expected</span> <span class='op'>==</span> <span class='kw-2'>&</span><span class='ident'>result_str</span>[..]);
}
<span class='comment'>// A normal addition - no overflow occurs</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_ok</span>() {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>add_bytes_to_bits</span>(<span class='number'>100</span>, <span class='number'>10</span>) <span class='op'>==</span> <span class='number'>180</span>);
}
<span class='comment'>// A simple failure case - adding 1 to the max value</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='attribute'>#[<span class='ident'>should_panic</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_overflow</span>() {
<span class='ident'>add_bytes_to_bits</span>(<span class='ident'>std</span>::<span class='ident'>u64</span>::<span class='ident'>MAX</span>, <span class='number'>1</span>);
}
<span class='comment'>// A normal addition - no overflow occurs (fast path)</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_tuple_ok</span>() {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>add_bytes_to_bits_tuple</span>((<span class='number'>5</span>, <span class='number'>100</span>), <span class='number'>10</span>) <span class='op'>==</span> (<span class='number'>5</span>, <span class='number'>180</span>));
}
<span class='comment'>// The low order value overflows into the high order value</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_tuple_ok2</span>() {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>add_bytes_to_bits_tuple</span>((<span class='number'>5</span>, <span class='ident'>std</span>::<span class='ident'>u64</span>::<span class='ident'>MAX</span>), <span class='number'>1</span>) <span class='op'>==</span> (<span class='number'>6</span>, <span class='number'>7</span>));
}
<span class='comment'>// The value to add is too large to be converted into bits without overflowing its type</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_tuple_ok3</span>() {
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>add_bytes_to_bits_tuple</span>((<span class='number'>5</span>, <span class='number'>0</span>), <span class='number'>0x4000000000000001</span>) <span class='op'>==</span> (<span class='number'>7</span>, <span class='number'>8</span>));
}
<span class='comment'>// A simple failure case - adding 1 to the max value</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='attribute'>#[<span class='ident'>should_panic</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_tuple_overflow</span>() {
<span class='ident'>add_bytes_to_bits_tuple</span>((<span class='ident'>std</span>::<span class='ident'>u64</span>::<span class='ident'>MAX</span>, <span class='ident'>std</span>::<span class='ident'>u64</span>::<span class='ident'>MAX</span>), <span class='number'>1</span>);
}
<span class='comment'>// The value to add is too large to convert to bytes without overflowing its type, but the high</span>
<span class='comment'>// order value from this conversion overflows when added to the existing high order value</span>
<span class='attribute'>#[<span class='ident'>test</span>]</span>
<span class='attribute'>#[<span class='ident'>should_panic</span>]</span>
<span class='kw'>fn</span> <span class='ident'>test_add_bytes_to_bits_tuple_overflow2</span>() {
<span class='kw'>let</span> <span class='ident'>value</span>: <span class='ident'>u64</span> <span class='op'>=</span> <span class='ident'>std</span>::<span class='ident'>u64</span>::<span class='ident'>MAX</span>;
<span class='ident'>add_bytes_to_bits_tuple</span>((<span class='ident'>value</span> <span class='op'>-</span> <span class='number'>1</span>, <span class='number'>0</span>), <span class='number'>0x8000000000000000</span>);
}
}
</pre>
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