| <!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/htmlescape-0.3.1/src/encode.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>encode.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="../../htmlescape/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="../../htmlescape/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span>std::io::{<span class="self">self</span>, Write}; |
| <span class="kw">use </span>std::char; |
| <span class="kw">use </span>io_support::{write_char}; |
| <span class="kw">use </span>entities::<span class="kw-2">*</span>; |
| |
| <span class="doccomment">/// |
| /// HTML entity-encode a string. |
| /// |
| /// Entity-encodes a string with a minimal set of entities: |
| /// |
| /// - `" -- &quot;` |
| /// - `& -- &amp;` |
| /// - `' -- &#x27;` |
| /// - `< -- &lt;` |
| /// - `> -- &gt;` |
| /// |
| /// # Arguments |
| /// - `s` - The string to encode. |
| /// |
| /// # Return value |
| /// The encoded string. |
| /// |
| /// # Example |
| /// ~~~ |
| /// let encoded = htmlescape::encode_minimal("<em>Hej!</em>"); |
| /// assert_eq!(&encoded, "&lt;em&gt;Hej!&lt;/em&gt;"); |
| /// ~~~ |
| /// |
| /// # Safety notes |
| /// Using the function to encode an untrusted string that is to be used as a HTML attribute value |
| /// may lead to XSS vulnerabilities. Consider the following example: |
| /// |
| /// ~~~ |
| /// let name = "dummy onmouseover=alert(/XSS/)"; // User input |
| /// let tag = format!("<option value={}>", htmlescape::encode_minimal(name)); |
| /// // Here `tag` is "<option value=dummy onmouseover=alert(/XSS/)>" |
| /// ~~~ |
| /// |
| /// Use `escape_attribute` for escaping HTML attribute values. |
| </span><span class="kw">pub fn </span>encode_minimal(s: <span class="kw-2">&</span>str) -> String { |
| <span class="kw">let </span><span class="kw-2">mut </span>writer = Vec::with_capacity((s.len()/<span class="number">3 </span>+ <span class="number">1</span>) * <span class="number">4</span>); |
| <span class="kw">match </span>encode_minimal_w(s, <span class="kw-2">&mut </span>writer) { |
| <span class="prelude-val">Err</span>(<span class="kw">_</span>) => <span class="macro">panic!</span>(), |
| <span class="prelude-val">Ok</span>(<span class="kw">_</span>) => String::from_utf8(writer).expect(<span class="string">"impossible invalid UTF-8 in output"</span>) |
| } |
| } |
| |
| <span class="doccomment">/// |
| /// HTML entity-encode a string to a writer. |
| /// |
| /// Similar to `encode_minimal`, except that the output is written to a writer rather |
| /// than returned as a `String`. |
| /// |
| /// # Arguments |
| /// - `s` - The string to encode. |
| /// - `writer` - Output is written to here. |
| </span><span class="kw">pub fn </span>encode_minimal_w<W: Write>(s: <span class="kw-2">&</span>str, writer: <span class="kw-2">&mut </span>W) -> io::Result<()> { |
| <span class="kw">for </span>c <span class="kw">in </span>s.chars() { |
| <span class="kw">match </span>get_entity(c) { |
| <span class="prelude-val">None </span>=> <span class="macro">try!</span>(write_char(writer, c)), |
| <span class="prelude-val">Some</span>(entity) => <span class="macro">try!</span>(writer.write_all(entity.as_bytes())) |
| } |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// |
| /// HTML entity-encodes a string for use in attributes values. |
| /// |
| /// Entity-encodes a string using an extensive set of entities, giving a string suitable for use |
| /// in HTML attribute values. All entities from `encode_minimal` are used, and further, all |
| /// non-alphanumeric ASCII characters are hex-encoded (`&#x__;`). |
| /// See the [OWASP XSS Prevention Cheat Sheet]( |
| /// https://www.owasp.org/index.php/XSS_(Cross_Site_Scripting)_Prevention_Cheat_Sheet) for more |
| /// information on entity-encoding for attribute values. |
| /// |
| /// # Arguments |
| /// - `s` - The string to encode. |
| /// |
| /// # Return value |
| /// The encoded string. |
| /// |
| /// # Example |
| /// ~~~ |
| /// let encoded = htmlescape::encode_attribute("\"No\", he said."); |
| /// assert_eq!(&encoded, "&quot;No&quot;&#x2C;&#x20;he&#x20;said&#x2E;"); |
| /// ~~~ |
| </span><span class="kw">pub fn </span>encode_attribute(s: <span class="kw-2">&</span>str) -> String { |
| <span class="kw">let </span><span class="kw-2">mut </span>writer = Vec::with_capacity(s.len() * <span class="number">3</span>); |
| <span class="kw">match </span>encode_attribute_w(s, <span class="kw-2">&mut </span>writer) { |
| <span class="prelude-val">Err</span>(<span class="kw">_</span>) => <span class="macro">panic!</span>(), |
| <span class="prelude-val">Ok</span>(<span class="kw">_</span>) => String::from_utf8(writer).unwrap() |
| } |
| } |
| |
| <span class="doccomment">/// |
| /// HTML entity-encodes a string, for use in attributes values, to a writer. |
| /// |
| /// Similar to `encode_attribute`, except that the output is written to a writer rather |
| /// than returned as a `String`. |
| /// |
| /// # Arguments |
| /// - `s` - The string to encode. |
| /// - `writer` - Output is written to here. |
| </span><span class="kw">pub fn </span>encode_attribute_w<W: Write>(s: <span class="kw-2">&</span>str, writer: <span class="kw-2">&mut </span>W) -> io::Result<()> { |
| <span class="kw">for </span>c <span class="kw">in </span>s.chars() { |
| <span class="kw">let </span>b = c <span class="kw">as </span>usize; |
| <span class="kw">let </span>res = <span class="kw">match </span>get_entity(c) { |
| <span class="prelude-val">Some</span>(entity) => writer.write_all(entity.as_bytes()), |
| <span class="prelude-val">None </span>=> |
| <span class="kw">if </span>b < <span class="number">256 </span>&& (b > <span class="number">127 </span>|| !is_ascii_alnum(c)) { |
| write_hex(writer, c) |
| } <span class="kw">else </span>{ |
| write_char(writer, c) |
| } |
| }; |
| <span class="macro">try!</span>(res); |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>get_entity(c: char) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'static </span>str> { |
| <span class="kw">match </span>MINIMAL_ENTITIES.binary_search_by(|<span class="kw-2">&</span>(ec, <span class="kw">_</span>)| ec.cmp(<span class="kw-2">&</span>c) ) { |
| <span class="prelude-val">Err</span>(..) => <span class="prelude-val">None</span>, |
| <span class="prelude-val">Ok</span>(idx) => { |
| <span class="kw">let </span>(<span class="kw">_</span>, e) = MINIMAL_ENTITIES[idx]; |
| <span class="prelude-val">Some</span>(e) |
| } |
| } |
| } |
| |
| <span class="kw">fn </span>write_hex<W: Write>(writer: <span class="kw-2">&mut </span>W, c: char) -> io::Result<()> { |
| <span class="kw">let </span>hex = <span class="string">b"0123456789ABCDEF"</span>; |
| <span class="macro">try!</span>(writer.write(<span class="string">b"&#x"</span>)); |
| <span class="kw">let </span>n = c <span class="kw">as </span>u8; |
| <span class="kw">let </span>bytes = [hex[((n & <span class="number">0xF0</span>) >> <span class="number">4</span>) <span class="kw">as </span>usize], |
| hex[(n & <span class="number">0x0F</span>) <span class="kw">as </span>usize], |
| <span class="string">b';'</span>]; |
| writer.write_all(<span class="kw-2">&</span>bytes) |
| } |
| |
| <span class="kw">fn </span>is_ascii_alnum(c: char) -> bool { |
| (c >= <span class="string">'a' </span>&& c <= <span class="string">'z'</span>) || (c >= <span class="string">'A' </span>&& c <= <span class="string">'Z'</span>) || (c >= <span class="string">'0' </span>&& c <= <span class="string">'9'</span>) |
| } |
| |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="htmlescape" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |