| <!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/base64-0.13.1/src/lib.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lib.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="../../base64/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="../../base64/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="doccomment">//! # Configs |
| //! |
| //! There isn't just one type of Base64; that would be too simple. You need to choose a character |
| //! set (standard, URL-safe, etc) and padding suffix (yes/no). |
| //! The `Config` struct encapsulates this info. There are some common configs included: `STANDARD`, |
| //! `URL_SAFE`, etc. You can also make your own `Config` if needed. |
| //! |
| //! The functions that don't have `config` in the name (e.g. `encode()` and `decode()`) use the |
| //! `STANDARD` config . |
| //! |
| //! The functions that write to a slice (the ones that end in `_slice`) are generally the fastest |
| //! because they don't need to resize anything. If it fits in your workflow and you care about |
| //! performance, keep using the same buffer (growing as need be) and use the `_slice` methods for |
| //! the best performance. |
| //! |
| //! # Encoding |
| //! |
| //! Several different encoding functions are available to you depending on your desire for |
| //! convenience vs performance. |
| //! |
| //! | Function | Output | Allocates | |
| //! | ----------------------- | ---------------------------- | ------------------------------ | |
| //! | `encode` | Returns a new `String` | Always | |
| //! | `encode_config` | Returns a new `String` | Always | |
| //! | `encode_config_buf` | Appends to provided `String` | Only if `String` needs to grow | |
| //! | `encode_config_slice` | Writes to provided `&[u8]` | Never | |
| //! |
| //! All of the encoding functions that take a `Config` will pad as per the config. |
| //! |
| //! # Decoding |
| //! |
| //! Just as for encoding, there are different decoding functions available. |
| //! |
| //! | Function | Output | Allocates | |
| //! | ----------------------- | ----------------------------- | ------------------------------ | |
| //! | `decode` | Returns a new `Vec<u8>` | Always | |
| //! | `decode_config` | Returns a new `Vec<u8>` | Always | |
| //! | `decode_config_buf` | Appends to provided `Vec<u8>` | Only if `Vec` needs to grow | |
| //! | `decode_config_slice` | Writes to provided `&[u8]` | Never | |
| //! |
| //! Unlike encoding, where all possible input is valid, decoding can fail (see `DecodeError`). |
| //! |
| //! Input can be invalid because it has invalid characters or invalid padding. (No padding at all is |
| //! valid, but excess padding is not.) Whitespace in the input is invalid. |
| //! |
| //! # `Read` and `Write` |
| //! |
| //! To map a `Read` of b64 bytes to the decoded bytes, wrap a reader (file, network socket, etc) |
| //! with `base64::read::DecoderReader`. To write raw bytes and have them b64 encoded on the fly, |
| //! wrap a writer with `base64::write::EncoderWriter`. There is some performance overhead (15% or |
| //! so) because of the necessary buffer shuffling -- still fast enough that almost nobody cares. |
| //! Also, these implementations do not heap allocate. |
| //! |
| //! # Panics |
| //! |
| //! If length calculations result in overflowing `usize`, a panic will result. |
| //! |
| //! The `_slice` flavors of encode or decode will panic if the provided output slice is too small, |
| |
| </span><span class="attribute">#![cfg_attr(feature = <span class="string">"cargo-clippy"</span>, allow(clippy::cast_lossless))] |
| #![deny( |
| missing_docs, |
| trivial_casts, |
| trivial_numeric_casts, |
| unused_extern_crates, |
| unused_import_braces, |
| unused_results, |
| variant_size_differences, |
| warnings |
| )] |
| #![forbid(unsafe_code)] |
| #![cfg_attr(not(any(feature = <span class="string">"std"</span>, test)), no_std)] |
| |
| #[cfg(all(feature = <span class="string">"alloc"</span>, not(any(feature = <span class="string">"std"</span>, test))))] |
| </span><span class="kw">extern crate </span>alloc; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">extern crate </span>std <span class="kw">as </span>alloc; |
| |
| <span class="kw">mod </span>chunked_encoder; |
| <span class="kw">pub mod </span>display; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub mod </span>read; |
| <span class="kw">mod </span>tables; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub mod </span>write; |
| |
| <span class="kw">mod </span>encode; |
| <span class="kw">pub use </span><span class="kw">crate</span>::encode::encode_config_slice; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"alloc"</span>, feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub use </span><span class="kw">crate</span>::encode::{encode, encode_config, encode_config_buf}; |
| |
| <span class="kw">mod </span>decode; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"alloc"</span>, feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub use </span><span class="kw">crate</span>::decode::{decode, decode_config, decode_config_buf}; |
| <span class="kw">pub use </span><span class="kw">crate</span>::decode::{decode_config_slice, DecodeError}; |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests; |
| |
| <span class="doccomment">/// Available encoding character sets |
| </span><span class="attribute">#[derive(Clone, Copy, Debug)] |
| </span><span class="kw">pub enum </span>CharacterSet { |
| <span class="doccomment">/// The standard character set (uses `+` and `/`). |
| /// |
| /// See [RFC 3548](https://tools.ietf.org/html/rfc3548#section-3). |
| </span>Standard, |
| <span class="doccomment">/// The URL safe character set (uses `-` and `_`). |
| /// |
| /// See [RFC 3548](https://tools.ietf.org/html/rfc3548#section-4). |
| </span>UrlSafe, |
| <span class="doccomment">/// The `crypt(3)` character set (uses `./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz`). |
| /// |
| /// Not standardized, but folk wisdom on the net asserts that this alphabet is what crypt uses. |
| </span>Crypt, |
| <span class="doccomment">/// The bcrypt character set (uses `./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789`). |
| </span>Bcrypt, |
| <span class="doccomment">/// The character set used in IMAP-modified UTF-7 (uses `+` and `,`). |
| /// |
| /// See [RFC 3501](https://tools.ietf.org/html/rfc3501#section-5.1.3) |
| </span>ImapMutf7, |
| <span class="doccomment">/// The character set used in BinHex 4.0 files. |
| /// |
| /// See [BinHex 4.0 Definition](http://files.stairways.com/other/binhex-40-specs-info.txt) |
| </span>BinHex, |
| } |
| |
| <span class="kw">impl </span>CharacterSet { |
| <span class="kw">fn </span>encode_table(<span class="self">self</span>) -> <span class="kw-2">&</span><span class="lifetime">'static </span>[u8; <span class="number">64</span>] { |
| <span class="kw">match </span><span class="self">self </span>{ |
| CharacterSet::Standard => tables::STANDARD_ENCODE, |
| CharacterSet::UrlSafe => tables::URL_SAFE_ENCODE, |
| CharacterSet::Crypt => tables::CRYPT_ENCODE, |
| CharacterSet::Bcrypt => tables::BCRYPT_ENCODE, |
| CharacterSet::ImapMutf7 => tables::IMAP_MUTF7_ENCODE, |
| CharacterSet::BinHex => tables::BINHEX_ENCODE, |
| } |
| } |
| |
| <span class="kw">fn </span>decode_table(<span class="self">self</span>) -> <span class="kw-2">&</span><span class="lifetime">'static </span>[u8; <span class="number">256</span>] { |
| <span class="kw">match </span><span class="self">self </span>{ |
| CharacterSet::Standard => tables::STANDARD_DECODE, |
| CharacterSet::UrlSafe => tables::URL_SAFE_DECODE, |
| CharacterSet::Crypt => tables::CRYPT_DECODE, |
| CharacterSet::Bcrypt => tables::BCRYPT_DECODE, |
| CharacterSet::ImapMutf7 => tables::IMAP_MUTF7_DECODE, |
| CharacterSet::BinHex => tables::BINHEX_DECODE, |
| } |
| } |
| } |
| |
| <span class="doccomment">/// Contains configuration parameters for base64 encoding |
| </span><span class="attribute">#[derive(Clone, Copy, Debug)] |
| </span><span class="kw">pub struct </span>Config { |
| <span class="doccomment">/// Character set to use |
| </span>char_set: CharacterSet, |
| <span class="doccomment">/// True to pad output with `=` characters |
| </span>pad: bool, |
| <span class="doccomment">/// True to ignore excess nonzero bits in the last few symbols, otherwise an error is returned. |
| </span>decode_allow_trailing_bits: bool, |
| } |
| |
| <span class="kw">impl </span>Config { |
| <span class="doccomment">/// Create a new `Config`. |
| </span><span class="kw">pub const fn </span>new(char_set: CharacterSet, pad: bool) -> Config { |
| Config { |
| char_set, |
| pad, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Sets whether to pad output with `=` characters. |
| </span><span class="kw">pub const fn </span>pad(<span class="self">self</span>, pad: bool) -> Config { |
| Config { pad, ..<span class="self">self </span>} |
| } |
| |
| <span class="doccomment">/// Sets whether to emit errors for nonzero trailing bits. |
| /// |
| /// This is useful when implementing |
| /// [forgiving-base64 decode](https://infra.spec.whatwg.org/#forgiving-base64-decode). |
| </span><span class="kw">pub const fn </span>decode_allow_trailing_bits(<span class="self">self</span>, allow: bool) -> Config { |
| Config { |
| decode_allow_trailing_bits: allow, |
| ..<span class="self">self |
| </span>} |
| } |
| } |
| |
| <span class="doccomment">/// Standard character set with padding. |
| </span><span class="kw">pub const </span>STANDARD: Config = Config { |
| char_set: CharacterSet::Standard, |
| pad: <span class="bool-val">true</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// Standard character set without padding. |
| </span><span class="kw">pub const </span>STANDARD_NO_PAD: Config = Config { |
| char_set: CharacterSet::Standard, |
| pad: <span class="bool-val">false</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// URL-safe character set with padding |
| </span><span class="kw">pub const </span>URL_SAFE: Config = Config { |
| char_set: CharacterSet::UrlSafe, |
| pad: <span class="bool-val">true</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// URL-safe character set without padding |
| </span><span class="kw">pub const </span>URL_SAFE_NO_PAD: Config = Config { |
| char_set: CharacterSet::UrlSafe, |
| pad: <span class="bool-val">false</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// As per `crypt(3)` requirements |
| </span><span class="kw">pub const </span>CRYPT: Config = Config { |
| char_set: CharacterSet::Crypt, |
| pad: <span class="bool-val">false</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// Bcrypt character set |
| </span><span class="kw">pub const </span>BCRYPT: Config = Config { |
| char_set: CharacterSet::Bcrypt, |
| pad: <span class="bool-val">false</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// IMAP modified UTF-7 requirements |
| </span><span class="kw">pub const </span>IMAP_MUTF7: Config = Config { |
| char_set: CharacterSet::ImapMutf7, |
| pad: <span class="bool-val">false</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="doccomment">/// BinHex character set |
| </span><span class="kw">pub const </span>BINHEX: Config = Config { |
| char_set: CharacterSet::BinHex, |
| pad: <span class="bool-val">false</span>, |
| decode_allow_trailing_bits: <span class="bool-val">false</span>, |
| }; |
| |
| <span class="kw">const </span>PAD_BYTE: u8 = <span class="string">b'='</span>; |
| </code></pre></div> |
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