mirror of https://github.com/aria2/aria2
128 lines
3.4 KiB
C++
128 lines
3.4 KiB
C++
/* <!-- copyright */
|
|
/*
|
|
* aria2 - a simple utility for downloading files faster
|
|
*
|
|
* Copyright (C) 2006 Tatsuhiro Tsujikawa
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
/* copyright --> */
|
|
#include "Base64.h"
|
|
|
|
string Base64::part_encode(const string& subplain)
|
|
{
|
|
static char base64_table[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', '+', '/',
|
|
};
|
|
|
|
int shift = 2;
|
|
char carry = 0;
|
|
bool ignore_flag = false;
|
|
string crypted;
|
|
|
|
for(unsigned int index = 0; index < subplain.size(); ++index) {
|
|
if(ignore_flag) {
|
|
crypted += '=';
|
|
} else {
|
|
char cur = subplain.at(index) >> shift | carry;
|
|
if(subplain.at(index) == 0) ignore_flag = true;
|
|
carry = (subplain.at(index) << (6-shift)) & 0x3F;
|
|
shift += 2;
|
|
crypted += base64_table[(unsigned int)cur];
|
|
}
|
|
}
|
|
if(subplain.at(subplain.size()-1) == 0) {
|
|
crypted += '=';
|
|
} else {
|
|
char cur = subplain.at(subplain.size()-1) & 0x3F;
|
|
crypted += base64_table[(unsigned int)cur];
|
|
}
|
|
|
|
return crypted;
|
|
}
|
|
|
|
string Base64::encode(const string& plainSrc)
|
|
{
|
|
string plain = plainSrc;
|
|
int remainder = plain.size() % 3;
|
|
if( remainder ) remainder = 3-remainder;
|
|
for(int i = 0; i < remainder; ++i) plain += (char)0;
|
|
string crypted;
|
|
int start_pos = 0;
|
|
for(unsigned int index = 0; plain.size() > index; index += 3) {
|
|
string subplain = plain.substr(start_pos, 3);
|
|
string subcrypted = part_encode(subplain);
|
|
start_pos += 3;
|
|
crypted += subcrypted;
|
|
}
|
|
return crypted;
|
|
}
|
|
|
|
char Base64::getValue(char ch)
|
|
{
|
|
char retch;
|
|
|
|
if(ch >= 'A' && ch <= 'Z') {
|
|
retch = ch-'A';
|
|
} else if(ch >= 'a' && ch <= 'z') {
|
|
retch = ch-'a'+26;
|
|
} else if(ch >= '0' && ch <= '9') {
|
|
retch = ch-'0'+52;
|
|
} else if(ch == '+') {
|
|
retch = 62;
|
|
} else if(ch == '/') {
|
|
retch = 63;
|
|
} else {
|
|
retch = 0;
|
|
}
|
|
return retch;
|
|
}
|
|
|
|
string Base64::part_decode(const string& subCrypted)
|
|
{
|
|
int shift = 2;
|
|
string plain;
|
|
|
|
for(unsigned int index = 0; index < subCrypted.size()-1; ++index) {
|
|
if(subCrypted.at(index) == '=') break;
|
|
char cur = getValue(subCrypted.at(index)) << shift;
|
|
char carry = getValue(subCrypted.at(index+1)) >> (6-shift);
|
|
shift += 2;
|
|
plain += cur | carry;
|
|
}
|
|
|
|
return plain;
|
|
}
|
|
|
|
string Base64::decode(const string& crypted)
|
|
{
|
|
string plain;
|
|
int sIndex = 0;
|
|
for(int index = 0; crypted.size() > (unsigned int)index; index +=4) {
|
|
string subCrypted = crypted.substr(sIndex, 4);
|
|
string subPlain = part_decode(subCrypted);
|
|
sIndex += 4;
|
|
plain += subPlain;
|
|
}
|
|
return plain;
|
|
}
|