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Diffstat (limited to 'vendor/base64/src/lib.rs')
| -rw-r--r-- | vendor/base64/src/lib.rs | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/vendor/base64/src/lib.rs b/vendor/base64/src/lib.rs new file mode 100644 index 00000000..579a7225 --- /dev/null +++ b/vendor/base64/src/lib.rs @@ -0,0 +1,277 @@ +//! Correct, fast, and configurable [base64][] decoding and encoding. Base64 +//! transports binary data efficiently in contexts where only plain text is +//! allowed. +//! +//! [base64]: https://developer.mozilla.org/en-US/docs/Glossary/Base64 +//! +//! # Usage +//! +//! Use an [`Engine`] to decode or encode base64, configured with the base64 +//! alphabet and padding behavior best suited to your application. +//! +//! ## Engine setup +//! +//! There is more than one way to encode a stream of bytes as “base64”. +//! Different applications use different encoding +//! [alphabets][alphabet::Alphabet] and +//! [padding behaviors][engine::general_purpose::GeneralPurposeConfig]. +//! +//! ### Encoding alphabet +//! +//! Almost all base64 [alphabets][alphabet::Alphabet] use `A-Z`, `a-z`, and +//! `0-9`, which gives nearly 64 characters (26 + 26 + 10 = 62), but they differ +//! in their choice of their final 2. +//! +//! Most applications use the [standard][alphabet::STANDARD] alphabet specified +//! in [RFC 4648][rfc-alphabet]. If that’s all you need, you can get started +//! quickly by using the pre-configured +//! [`STANDARD`][engine::general_purpose::STANDARD] engine, which is also available +//! in the [`prelude`] module as shown here, if you prefer a minimal `use` +//! footprint. +//! +#![cfg_attr(feature = "alloc", doc = "```")] +#![cfg_attr(not(feature = "alloc"), doc = "```ignore")] +//! use base64::prelude::*; +//! +//! # fn main() -> Result<(), base64::DecodeError> { +//! assert_eq!(BASE64_STANDARD.decode(b"+uwgVQA=")?, b"\xFA\xEC\x20\x55\0"); +//! assert_eq!(BASE64_STANDARD.encode(b"\xFF\xEC\x20\x55\0"), "/+wgVQA="); +//! # Ok(()) +//! # } +//! ``` +//! +//! [rfc-alphabet]: https://datatracker.ietf.org/doc/html/rfc4648#section-4 +//! +//! Other common alphabets are available in the [`alphabet`] module. +//! +//! #### URL-safe alphabet +//! +//! The standard alphabet uses `+` and `/` as its two non-alphanumeric tokens, +//! which cannot be safely used in URL’s without encoding them as `%2B` and +//! `%2F`. +//! +//! To avoid that, some applications use a [“URL-safe” alphabet][alphabet::URL_SAFE], +//! which uses `-` and `_` instead. To use that alternative alphabet, use the +//! [`URL_SAFE`][engine::general_purpose::URL_SAFE] engine. This example doesn't +//! use [`prelude`] to show what a more explicit `use` would look like. +//! +#![cfg_attr(feature = "alloc", doc = "```")] +#![cfg_attr(not(feature = "alloc"), doc = "```ignore")] +//! use base64::{engine::general_purpose::URL_SAFE, Engine as _}; +//! +//! # fn main() -> Result<(), base64::DecodeError> { +//! assert_eq!(URL_SAFE.decode(b"-uwgVQA=")?, b"\xFA\xEC\x20\x55\0"); +//! assert_eq!(URL_SAFE.encode(b"\xFF\xEC\x20\x55\0"), "_-wgVQA="); +//! # Ok(()) +//! # } +//! ``` +//! +//! ### Padding characters +//! +//! Each base64 character represents 6 bits (2⁶ = 64) of the original binary +//! data, and every 3 bytes of input binary data will encode to 4 base64 +//! characters (8 bits × 3 = 6 bits × 4 = 24 bits). +//! +//! When the input is not an even multiple of 3 bytes in length, [canonical][] +//! base64 encoders insert padding characters at the end, so that the output +//! length is always a multiple of 4: +//! +//! [canonical]: https://datatracker.ietf.org/doc/html/rfc4648#section-3.5 +//! +#![cfg_attr(feature = "alloc", doc = "```")] +#![cfg_attr(not(feature = "alloc"), doc = "```ignore")] +//! use base64::{engine::general_purpose::STANDARD, Engine as _}; +//! +//! assert_eq!(STANDARD.encode(b""), ""); +//! assert_eq!(STANDARD.encode(b"f"), "Zg=="); +//! assert_eq!(STANDARD.encode(b"fo"), "Zm8="); +//! assert_eq!(STANDARD.encode(b"foo"), "Zm9v"); +//! ``` +//! +//! Canonical encoding ensures that base64 encodings will be exactly the same, +//! byte-for-byte, regardless of input length. But the `=` padding characters +//! aren’t necessary for decoding, and they may be omitted by using a +//! [`NO_PAD`][engine::general_purpose::NO_PAD] configuration: +//! +#![cfg_attr(feature = "alloc", doc = "```")] +#![cfg_attr(not(feature = "alloc"), doc = "```ignore")] +//! use base64::{engine::general_purpose::STANDARD_NO_PAD, Engine as _}; +//! +//! assert_eq!(STANDARD_NO_PAD.encode(b""), ""); +//! assert_eq!(STANDARD_NO_PAD.encode(b"f"), "Zg"); +//! assert_eq!(STANDARD_NO_PAD.encode(b"fo"), "Zm8"); +//! assert_eq!(STANDARD_NO_PAD.encode(b"foo"), "Zm9v"); +//! ``` +//! +//! The pre-configured `NO_PAD` engines will reject inputs containing padding +//! `=` characters. To encode without padding and still accept padding while +//! decoding, create an [engine][engine::general_purpose::GeneralPurpose] with +//! that [padding mode][engine::DecodePaddingMode]. +//! +#![cfg_attr(feature = "alloc", doc = "```")] +#![cfg_attr(not(feature = "alloc"), doc = "```ignore")] +//! # use base64::{engine::general_purpose::STANDARD_NO_PAD, Engine as _}; +//! assert_eq!(STANDARD_NO_PAD.decode(b"Zm8="), Err(base64::DecodeError::InvalidPadding)); +//! ``` +//! +//! ### Further customization +//! +//! Decoding and encoding behavior can be customized by creating an +//! [engine][engine::GeneralPurpose] with an [alphabet][alphabet::Alphabet] and +//! [padding configuration][engine::GeneralPurposeConfig]: +//! +#![cfg_attr(feature = "alloc", doc = "```")] +#![cfg_attr(not(feature = "alloc"), doc = "```ignore")] +//! use base64::{engine, alphabet, Engine as _}; +//! +//! // bizarro-world base64: +/ as the first symbols instead of the last +//! let alphabet = +//! alphabet::Alphabet::new("+/ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") +//! .unwrap(); +//! +//! // a very weird config that encodes with padding but requires no padding when decoding...? +//! let crazy_config = engine::GeneralPurposeConfig::new() +//! .with_decode_allow_trailing_bits(true) +//! .with_encode_padding(true) +//! .with_decode_padding_mode(engine::DecodePaddingMode::RequireNone); +//! +//! let crazy_engine = engine::GeneralPurpose::new(&alphabet, crazy_config); +//! +//! let encoded = crazy_engine.encode(b"abc 123"); +//! +//! ``` +//! +//! ## Memory allocation +//! +//! The [decode][Engine::decode()] and [encode][Engine::encode()] engine methods +//! allocate memory for their results – `decode` returns a `Vec<u8>` and +//! `encode` returns a `String`. To instead decode or encode into a buffer that +//! you allocated, use one of the alternative methods: +//! +//! #### Decoding +//! +//! | Method | Output | Allocates memory | +//! | -------------------------- | ----------------------------- | ----------------------------- | +//! | [`Engine::decode`] | returns a new `Vec<u8>` | always | +//! | [`Engine::decode_vec`] | appends to provided `Vec<u8>` | if `Vec` lacks capacity | +//! | [`Engine::decode_slice`] | writes to provided `&[u8]` | never +//! +//! #### Encoding +//! +//! | Method | Output | Allocates memory | +//! | -------------------------- | ---------------------------- | ------------------------------ | +//! | [`Engine::encode`] | returns a new `String` | always | +//! | [`Engine::encode_string`] | appends to provided `String` | if `String` lacks capacity | +//! | [`Engine::encode_slice`] | writes to provided `&[u8]` | never | +//! +//! ## Input and output +//! +//! The `base64` crate can [decode][Engine::decode()] and +//! [encode][Engine::encode()] values in memory, or +//! [`DecoderReader`][read::DecoderReader] and +//! [`EncoderWriter`][write::EncoderWriter] provide streaming decoding and +//! encoding for any [readable][std::io::Read] or [writable][std::io::Write] +//! byte stream. +//! +//! #### Decoding +//! +#![cfg_attr(feature = "std", doc = "```")] +#![cfg_attr(not(feature = "std"), doc = "```ignore")] +//! # use std::io; +//! use base64::{engine::general_purpose::STANDARD, read::DecoderReader}; +//! +//! # fn main() -> Result<(), Box<dyn std::error::Error>> { +//! let mut input = io::stdin(); +//! let mut decoder = DecoderReader::new(&mut input, &STANDARD); +//! io::copy(&mut decoder, &mut io::stdout())?; +//! # Ok(()) +//! # } +//! ``` +//! +//! #### Encoding +//! +#![cfg_attr(feature = "std", doc = "```")] +#![cfg_attr(not(feature = "std"), doc = "```ignore")] +//! # use std::io; +//! use base64::{engine::general_purpose::STANDARD, write::EncoderWriter}; +//! +//! # fn main() -> Result<(), Box<dyn std::error::Error>> { +//! let mut output = io::stdout(); +//! let mut encoder = EncoderWriter::new(&mut output, &STANDARD); +//! io::copy(&mut io::stdin(), &mut encoder)?; +//! # Ok(()) +//! # } +//! ``` +//! +//! #### Display +//! +//! If you only need a base64 representation for implementing the +//! [`Display`][std::fmt::Display] trait, use +//! [`Base64Display`][display::Base64Display]: +//! +//! ``` +//! use base64::{display::Base64Display, engine::general_purpose::STANDARD}; +//! +//! let value = Base64Display::new(b"\0\x01\x02\x03", &STANDARD); +//! assert_eq!("base64: AAECAw==", format!("base64: {}", value)); +//! ``` +//! +//! # Panics +//! +//! If length calculations result in overflowing `usize`, a panic will result. + +#![cfg_attr(feature = "cargo-clippy", allow(clippy::cast_lossless))] +#![deny( + missing_docs, + trivial_casts, + trivial_numeric_casts, + unused_extern_crates, + unused_import_braces, + unused_results, + variant_size_differences +)] +#![forbid(unsafe_code)] +// Allow globally until https://github.com/rust-lang/rust-clippy/issues/8768 is resolved. +// The desired state is to allow it only for the rstest_reuse import. +#![allow(clippy::single_component_path_imports)] +#![cfg_attr(not(any(feature = "std", test)), no_std)] + +#[cfg(any(feature = "alloc", test))] +extern crate alloc; + +// has to be included at top level because of the way rstest_reuse defines its macros +#[cfg(test)] +use rstest_reuse; + +mod chunked_encoder; +pub mod display; +#[cfg(any(feature = "std", test))] +pub mod read; +#[cfg(any(feature = "std", test))] +pub mod write; + +pub mod engine; +pub use engine::Engine; + +pub mod alphabet; + +mod encode; +#[allow(deprecated)] +#[cfg(any(feature = "alloc", test))] +pub use crate::encode::{encode, encode_engine, encode_engine_string}; +#[allow(deprecated)] +pub use crate::encode::{encode_engine_slice, encoded_len, EncodeSliceError}; + +mod decode; +#[allow(deprecated)] +#[cfg(any(feature = "alloc", test))] +pub use crate::decode::{decode, decode_engine, decode_engine_vec}; +#[allow(deprecated)] +pub use crate::decode::{decode_engine_slice, decoded_len_estimate, DecodeError, DecodeSliceError}; + +pub mod prelude; + +#[cfg(test)] +mod tests; + +const PAD_BYTE: u8 = b'='; |