1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169
use std::{fmt, error, string}; use std::error::Error; use std::string::FromUtf8Error; const CHARMAP: [u8; 64] = [ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2F ]; #[derive(Debug)] pub enum Base64Error { Utf8(string::FromUtf8Error), InvalidByte(usize, u8), InvalidLength } impl fmt::Display for Base64Error { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { match *self { Base64Error::Utf8(ref err) => err.fmt(f), Base64Error::InvalidByte(index, byte) => write!(f, "Invalid byte {}, offset {}.", byte, index), Base64Error::InvalidLength => write!(f, "Encoded text cannot have a 6-bit remainder.") } } } impl error::Error for Base64Error { fn description(&self) -> &str { match *self { Base64Error::Utf8(ref err) => err.description(), Base64Error::InvalidByte(_,_) => "invalid byte", Base64Error::InvalidLength => "invalid length" } } fn cause(&self) -> Option<&error::Error> { match *self { Base64Error::Utf8(ref err) => Some(err as &error::Error), _ => None } } } impl From<string::FromUtf8Error> for Base64Error { fn from(err: string::FromUtf8Error) -> Base64Error { Base64Error::Utf8(err) } } pub fn encode(input: &str) -> Result<String, Base64Error> { match u8en(input.as_bytes()) { Ok(bytes) => Ok(try!(String::from_utf8(bytes))), Err(err) => Err(err) } } pub fn decode(input: &str) -> Result<String, Base64Error> { match u8de(input.as_bytes()) { Ok(bytes) => Ok(try!(String::from_utf8(bytes))), Err(err) => Err(err) } } pub fn decode_ws(input: &str) -> Result<String, Base64Error> { let bytes = input.as_bytes(); let mut raw = Vec::<u8>::with_capacity(input.len()); for i in 0..input.len() { if !(bytes[i] == 0x20 || bytes[i] == 0x9 || bytes[i] == 0xa || bytes[i] == 0xc || bytes[i] == 0xd) { raw.push(bytes[i]); } } match u8de(&raw) { Ok(bytes) => Ok(try!(String::from_utf8(bytes))), Err(err) => Err(err) } } pub fn u8en(bytes: &[u8]) -> Result<Vec<u8>, Base64Error> { let rem = bytes.len() % 3; let div = bytes.len() - rem; let mut raw = Vec::<u8>::with_capacity(4*div/3 + if rem == 0 {4} else {0}); let mut i = 0; while i < div { raw.push(CHARMAP[(bytes[i] >> 2) as usize]); raw.push(CHARMAP[((bytes[i] << 4 | bytes[i+1] >> 4) & 0x3f) as usize]); raw.push(CHARMAP[((bytes[i+1] << 2 | bytes[i+2] >> 6) & 0x3f) as usize]); raw.push(CHARMAP[(bytes[i+2] & 0x3f) as usize]); i+=3; } if rem == 2 { raw.push(CHARMAP[(bytes[div] >> 2) as usize]); raw.push(CHARMAP[((bytes[div] << 4 | bytes[div+1] >> 4) & 0x3f) as usize]); raw.push(CHARMAP[(bytes[div+1] << 2 & 0x3f) as usize]); } else if rem == 1 { raw.push(CHARMAP[(bytes[div] >> 2) as usize]); raw.push(CHARMAP[(bytes[div] << 4 & 0x3f) as usize]); } for _ in 0..(3-rem)%3 { raw.push(0x3d); } Ok(raw) } pub fn u8de(bytes: &[u8]) -> Result<Vec<u8>, Base64Error> { let mut buffer = Vec::<u8>::with_capacity(bytes.len()); for i in 0..bytes.len() { if bytes[i] > 0x40 && bytes[i] < 0x5b { buffer.push(bytes[i] - 0x41); } else if bytes[i] > 0x60 && bytes[i] < 0x7b { buffer.push(bytes[i] - 0x61 + 0x1a); } else if bytes[i] > 0x2f && bytes[i] < 0x3a { buffer.push(bytes[i] - 0x30 + 0x34); } else if bytes[i] == 0x2b { buffer.push(0x3e); } else if bytes[i] == 0x2f { buffer.push(0x3f); } else if bytes[i] == 0x3d { ; } else { return Err(Base64Error::InvalidByte(i, bytes[i])); } } let rem = buffer.len() % 4; if rem == 1 { return Err(Base64Error::InvalidLength); } let div = buffer.len() - rem; let mut raw = Vec::<u8>::with_capacity(3*div/4 + rem); let mut i = 0; while i < div { raw.push(buffer[i] << 2 | buffer[i+1] >> 4); raw.push(buffer[i+1] << 4 | buffer[i+2] >> 2); raw.push(buffer[i+2] << 6 | buffer[i+3]); i+=4; } if rem > 1 { raw.push(buffer[div] << 2 | buffer[div+1] >> 4); } if rem > 2 { raw.push(buffer[div+1] << 4 | buffer[div+2] >> 2); } Ok(raw) }