/*
* Copyright: (c) 2008 Artyom Beilise
* License: MIT
* Other Copyrights:
* 7 lines of code had taken from: http://base64.sourceforge.net/b64.c
* and they are subject to MIT license by (c) Trantor Standard Systems Inc., 2001
*/
#define CPPCMS_SOURCE
#include <cppcms/base64.h>
#include <vector>
#include <ostream>
namespace {
const unsigned char encode_6_to_8[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
inline unsigned char encode_8_to_6(unsigned char c)
{
if('A'<=c && c<='Z')
return c - 'A';
if('a'<=c && c<='z')
return ('Z'-'A' + 1) + c - 'a';
if('0'<=c && c<='9')
return 2*('Z'-'A' + 1) + c - '0';
if(c=='-')
return 62;
if(c=='_')
return 63;
return 0;
}
size_t inline bencode(unsigned const char in[3],unsigned char out[4],size_t len)
{
out[0] = encode_6_to_8[in[0] >> 2];
if(len<=1) {
out[1] = encode_6_to_8[(in[0] & 0x03) << 4];
return 2;
}
else {
out[1] = encode_6_to_8[((in[0] & 0x03) << 4) | ((in[1] & 0xf0) >> 4)];
if(len<=2) {
out[2] = encode_6_to_8[(in[1] & 0x0f) << 2];
return 3;
}
else {
out[2] = encode_6_to_8[((in[1] & 0x0f) << 2) | ((in[2] & 0xc0) >> 6)];
out[3] = encode_6_to_8[in[2] & 0x3f];
return 4;
}
}
}
inline size_t bdecode(unsigned const char in8[4],unsigned char out[3],size_t len)
{
unsigned char in[4] = { 0 };
for(unsigned i=0;i<len;i++)
in[i]=encode_8_to_6(in8[i]);
out[ 0 ] = (unsigned char ) (in[0] << 2 | in[1] >> 4);
if(len==2) {
return 1;
}
else {
out[ 1 ] = (unsigned char ) (in[1] << 4 | in[2] >> 2);
if(len==3) {
return 2;
}
else {
out[ 2 ] = (unsigned char ) (((in[2] << 6) & 0xc0) | in[3]);
return 3;
}
}
}
} // anon namespace
namespace cppcms {
namespace b64url {
int encoded_size(size_t s)
{
switch(s % 3) {
case 1: return s/3*4+2;
case 2: return s/3*4+3;
default:
return s/3*4;
}
}
int decoded_size(size_t s)
{
switch(s % 4) {
case 1: return -1; // invalid
case 2: return s/4*3+1;
case 3: return s/4*3+2;
default:
return s/4*3;
}
}
unsigned char *encode(unsigned char const *begin,unsigned char const *end,unsigned char *target)
{
while(end - begin >=3) {
bencode(begin,target,3);
begin += 3;
target += 4;
}
if(end!=begin)
target+=bencode(begin,target,end-begin);
return target;
}
void encode(unsigned char const *begin,unsigned char const *end,std::ostream &out)
{
unsigned char target[4];
while(end - begin >=3) {
bencode(begin,target,3);
begin += 3;
out.write(reinterpret_cast<char *>(target),4);
}
if(end!=begin) {
int n = bencode(begin,target,end-begin);
out.write(reinterpret_cast<char *>(target),n);
}
}
unsigned char *decode(unsigned char const *begin,unsigned char const *end,unsigned char *target)
{
while(end - begin >=4) {
bdecode(begin,target,4);
begin+=4;
target+=3;
}
if(end!=begin)
target+=bdecode(begin,target,end-begin);
return target;
}
bool CPPCMS_API decode(std::string const &input,std::string &output)
{
int ds = decoded_size(input.size());
if(ds < 0)
return false;
if(ds == 0)
return true;
unsigned char const *begin = reinterpret_cast<unsigned char const *>(input.c_str());
unsigned char const *end = begin + input.size();
std::vector<char> buf(ds,0);
unsigned char *outbuf = reinterpret_cast<unsigned char *>(&buf[0]);
decode(begin,end,outbuf);
output.assign(&buf[0],ds);
return true;
}
///
/// Perform base64 URL encoding of the binary data \a input, and return it
///
///
std::string CPPCMS_API encode(std::string const &input)
{
std::string result;
size_t enc_size = encoded_size(input.size());
if(enc_size == 0)
return result;
unsigned char const *begin = reinterpret_cast<unsigned char const *>(input.c_str());
unsigned char const *end = begin + input.size();
std::vector<char> buf(enc_size,0);
unsigned char *outbuf = reinterpret_cast<unsigned char *>(&buf[0]);
encode(begin,end,outbuf);
result.assign(&buf[0],enc_size);
return result;
}
} // b64url
} // cppcms
