rust/src/libextra/base64.rs
2013-07-24 09:45:20 -04:00

392 lines
12 KiB
Rust

// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Base64 binary-to-text encoding
/// Available encoding character sets
pub enum CharacterSet {
/// The standard character set (uses '+' and '/')
Standard,
/// The URL safe character set (uses '-' and '_')
UrlSafe
}
/// Contains configuration parameters for to_base64
pub struct Config {
/// Character set to use
char_set: CharacterSet,
/// True to pad output with '=' characters
pad: bool,
/// Some(len) to wrap lines at len, None to disable line wrapping
line_length: Option<uint>
}
/// Configuration for RFC 4648 standard base64 encoding
pub static STANDARD: Config =
Config {char_set: Standard, pad: true, line_length: None};
/// Configuration for RFC 4648 base64url encoding
pub static URL_SAFE: Config =
Config {char_set: UrlSafe, pad: false, line_length: None};
/// Configuration for RFC 2045 MIME base64 encoding
pub static MIME: Config =
Config {char_set: Standard, pad: true, line_length: Some(76)};
static STANDARD_CHARS: [char, ..64] = [
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
];
static URLSAFE_CHARS: [char, ..64] = [
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'
];
/// A trait for converting a value to base64 encoding.
pub trait ToBase64 {
/// Converts the value of `self` to a base64 value following the specified
/// format configuration, returning the owned string.
fn to_base64(&self, config: Config) -> ~str;
}
impl<'self> ToBase64 for &'self [u8] {
/**
* Turn a vector of `u8` bytes into a base64 string.
*
* # Example
*
* ~~~ {.rust}
* extern mod extra;
* use extra::base64::{ToBase64, standard};
*
* fn main () {
* let str = [52,32].to_base64(standard);
* printfln!("%s", str);
* }
* ~~~
*/
fn to_base64(&self, config: Config) -> ~str {
let chars = match config.char_set {
Standard => STANDARD_CHARS,
UrlSafe => URLSAFE_CHARS
};
let mut s = ~"";
let mut i = 0;
let mut cur_length = 0;
let len = self.len();
while i < len - (len % 3) {
match config.line_length {
Some(line_length) =>
if cur_length >= line_length {
s.push_str("\r\n");
cur_length = 0;
},
None => ()
}
let n = (self[i] as u32) << 16 |
(self[i + 1] as u32) << 8 |
(self[i + 2] as u32);
// This 24-bit number gets separated into four 6-bit numbers.
s.push_char(chars[(n >> 18) & 63]);
s.push_char(chars[(n >> 12) & 63]);
s.push_char(chars[(n >> 6 ) & 63]);
s.push_char(chars[n & 63]);
cur_length += 4;
i += 3;
}
if len % 3 != 0 {
match config.line_length {
Some(line_length) =>
if cur_length >= line_length {
s.push_str("\r\n");
},
None => ()
}
}
// Heh, would be cool if we knew this was exhaustive
// (the dream of bounded integer types)
match len % 3 {
0 => (),
1 => {
let n = (self[i] as u32) << 16;
s.push_char(chars[(n >> 18) & 63]);
s.push_char(chars[(n >> 12) & 63]);
if config.pad {
s.push_str("==");
}
}
2 => {
let n = (self[i] as u32) << 16 |
(self[i + 1u] as u32) << 8;
s.push_char(chars[(n >> 18) & 63]);
s.push_char(chars[(n >> 12) & 63]);
s.push_char(chars[(n >> 6 ) & 63]);
if config.pad {
s.push_char('=');
}
}
_ => fail!("Algebra is broken, please alert the math police")
}
s
}
}
impl<'self> ToBase64 for &'self str {
/**
* Convert any string (literal, `@`, `&`, or `~`) to base64 encoding.
*
*
* # Example
*
* ~~~ {.rust}
* extern mod extra;
* use extra::base64::{ToBase64, standard};
*
* fn main () {
* let str = "Hello, World".to_base64(standard);
* printfln!("%s", str);
* }
* ~~~
*
*/
fn to_base64(&self, config: Config) -> ~str {
self.as_bytes().to_base64(config)
}
}
/// A trait for converting from base64 encoded values.
pub trait FromBase64 {
/// Converts the value of `self`, interpreted as base64 encoded data, into
/// an owned vector of bytes, returning the vector.
fn from_base64(&self) -> Result<~[u8], ~str>;
}
impl<'self> FromBase64 for &'self [u8] {
/**
* Convert base64 `u8` vector into u8 byte values.
* Every 4 encoded characters is converted into 3 octets, modulo padding.
*
* # Example
*
* ~~~ {.rust}
* extern mod extra;
* use extra::base64::{ToBase64, FromBase64, standard};
*
* fn main () {
* let str = [52,32].to_base64(standard);
* printfln!("%s", str);
* let bytes = str.from_base64();
* printfln!("%?", bytes);
* }
* ~~~
*/
fn from_base64(&self) -> Result<~[u8], ~str> {
let mut r = ~[];
let mut buf: u32 = 0;
let mut modulus = 0;
let mut it = self.iter();
for it.advance |&byte| {
let ch = byte as char;
let val = byte as u32;
match ch {
'A'..'Z' => buf |= val - 0x41,
'a'..'z' => buf |= val - 0x47,
'0'..'9' => buf |= val + 0x04,
'+'|'-' => buf |= 0x3E,
'/'|'_' => buf |= 0x3F,
'\r'|'\n' => loop,
'=' => break,
_ => return Err(~"Invalid Base64 character")
}
buf <<= 6;
modulus += 1;
if modulus == 4 {
modulus = 0;
r.push((buf >> 22) as u8);
r.push((buf >> 14) as u8);
r.push((buf >> 6 ) as u8);
}
}
if !it.all(|&byte| {byte as char == '='}) {
return Err(~"Invalid Base64 character");
}
match modulus {
2 => {
r.push((buf >> 10) as u8);
}
3 => {
r.push((buf >> 16) as u8);
r.push((buf >> 8 ) as u8);
}
0 => (),
_ => return Err(~"Invalid Base64 length")
}
Ok(r)
}
}
impl<'self> FromBase64 for &'self str {
/**
* Convert any base64 encoded string (literal, `@`, `&`, or `~`)
* to the byte values it encodes.
*
* You can use the `from_bytes` function in `std::str`
* to turn a `[u8]` into a string with characters corresponding to those
* values.
*
* # Example
*
* This converts a string literal to base64 and back.
*
* ~~~ {.rust}
* extern mod extra;
* use extra::base64::{ToBase64, FromBase64, standard};
* use std::str;
*
* fn main () {
* let hello_str = "Hello, World".to_base64(standard);
* printfln!("%s", hello_str);
* let bytes = hello_str.from_base64();
* printfln!("%?", bytes);
* let result_str = str::from_bytes(bytes);
* printfln!("%s", result_str);
* }
* ~~~
*/
fn from_base64(&self) -> Result<~[u8], ~str> {
self.as_bytes().from_base64()
}
}
#[cfg(test)]
mod test {
use test::BenchHarness;
use base64::*;
#[test]
fn test_to_base64_basic() {
assert_eq!("".to_base64(STANDARD), ~"");
assert_eq!("f".to_base64(STANDARD), ~"Zg==");
assert_eq!("fo".to_base64(STANDARD), ~"Zm8=");
assert_eq!("foo".to_base64(STANDARD), ~"Zm9v");
assert_eq!("foob".to_base64(STANDARD), ~"Zm9vYg==");
assert_eq!("fooba".to_base64(STANDARD), ~"Zm9vYmE=");
assert_eq!("foobar".to_base64(STANDARD), ~"Zm9vYmFy");
}
#[test]
fn test_to_base64_line_break() {
assert!(![0u8, 1000].to_base64(Config {line_length: None, ..STANDARD})
.contains("\r\n"));
assert_eq!("foobar".to_base64(Config {line_length: Some(4), ..STANDARD}),
~"Zm9v\r\nYmFy");
}
#[test]
fn test_to_base64_padding() {
assert_eq!("f".to_base64(Config {pad: false, ..STANDARD}), ~"Zg");
assert_eq!("fo".to_base64(Config {pad: false, ..STANDARD}), ~"Zm8");
}
#[test]
fn test_to_base64_url_safe() {
assert_eq!([251, 255].to_base64(URL_SAFE), ~"-_8");
assert_eq!([251, 255].to_base64(STANDARD), ~"+/8=");
}
#[test]
fn test_from_base64_basic() {
assert_eq!("".from_base64().get(), "".as_bytes().to_owned());
assert_eq!("Zg==".from_base64().get(), "f".as_bytes().to_owned());
assert_eq!("Zm8=".from_base64().get(), "fo".as_bytes().to_owned());
assert_eq!("Zm9v".from_base64().get(), "foo".as_bytes().to_owned());
assert_eq!("Zm9vYg==".from_base64().get(), "foob".as_bytes().to_owned());
assert_eq!("Zm9vYmE=".from_base64().get(), "fooba".as_bytes().to_owned());
assert_eq!("Zm9vYmFy".from_base64().get(), "foobar".as_bytes().to_owned());
}
#[test]
fn test_from_base64_newlines() {
assert_eq!("Zm9v\r\nYmFy".from_base64().get(),
"foobar".as_bytes().to_owned());
}
#[test]
fn test_from_base64_urlsafe() {
assert_eq!("-_8".from_base64().get(), "+/8=".from_base64().get());
}
#[test]
fn test_from_base64_invalid_char() {
assert!("Zm$=".from_base64().is_err())
assert!("Zg==$".from_base64().is_err());
}
#[test]
fn test_from_base64_invalid_padding() {
assert!("Z===".from_base64().is_err());
}
#[test]
fn test_base64_random() {
use std::rand::{task_rng, random, RngUtil};
use std::vec;
for 1000.times {
let v: ~[u8] = do vec::build |push| {
for task_rng().gen_uint_range(1, 100).times {
push(random());
}
};
assert_eq!(v.to_base64(STANDARD).from_base64().get(), v);
}
}
#[bench]
pub fn to_base64(bh: & mut BenchHarness) {
let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
do bh.iter {
s.to_base64(STANDARD);
}
bh.bytes = s.len() as u64;
}
#[bench]
pub fn from_base64(bh: & mut BenchHarness) {
let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
let b = s.to_base64(STANDARD);
do bh.iter {
b.from_base64();
}
bh.bytes = b.len() as u64;
}
}