키워드 [Programming][VC++][Base64]
걍 라이브러리로 만들어 놓은 것 중에서.. 일부를 뽑아 소스를 올린다.
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// base64 인코딩/디코딩 및 제거
// base64.h
K4LIB_BASIC_API unsigned char* base64_encode(const unsigned char *string, int length, int *ret_length);
K4LIB_BASIC_API unsigned char* base64_decode(const unsigned char *string, int length, int *ret_length);
K4LIB_BASIC_API void base64_free(unsigned char* data);
/////////////////////////////////////////////////////////////
// base64 인코딩/디코딩 및 제거
// base64.cpp
static char base64_table[] =
{ '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', '+', '/', '\0'
};
static char base64_pad = '=';
unsigned char *base64_encode(const unsigned char *string, int length, int *ret_length)
{
const unsigned char *current = string;
int i = 0;
int wi = 0;
int nAllocSize = ((length + 3 - length
% 3) * 4 / 3 + 1) * sizeof(char);
nAllocSize += (nAllocSize/80+1)*2;
unsigned char *result = new unsigned char[nAllocSize];
while (length > 2)
{ /* keep going until we have less than 24 bits */
result[i++] = base64_table[current[0] >> 2];
result[i++] = base64_table[((current[0] & 0x03) << 4)
+ (current[1] >> 4)];
result[i++] = base64_table[((current[1] & 0x0f) << 2)
+ (current[2] >> 6)];
result[i++] = base64_table[current[2] & 0x3f];
current += 3;
length -= 3; /* we just handle 3 octets of data */
wi+=4;
/* if(wi%80 == 0)
{
result[i++] = '\r';
result[i++] = '\n';
}
*/ }
/* now deal with the tail end of things */
if (length != 0)
{
result[i++] = base64_table[current[0] >> 2];
if (length > 1)
{
result[i++] = base64_table[((current[0] &
0x03) << 4) + (current[1] >> 4)];
result[i++] = base64_table[(current[1] &
0x0f) << 2];
result[i++] = base64_pad;
}else
{
result[i++] = base64_table[(current[0] &
0x03) << 4];
result[i++] = base64_pad;
result[i++] = base64_pad;
}
}
if(ret_length)
{
*ret_length = i;
}
result[i] = '\0';
return result;
}
/* as above, but backwards. :) */
unsigned char *base64_decode(const unsigned char *string, int length, int *ret_length)
{
const unsigned char *current = string;
int ch, i = 0, j = 0, k;
char *chp;
unsigned char *result = new unsigned char[(length / 4 *3 + 1) * sizeof(char)];
if (result == NULL) {
return NULL;
}
/* run through the whole string, converting as we go */
while ((ch = *current++) != '\0') {
if (ch == base64_pad) break;
chp = strchr(base64_table, ch);
if (chp == NULL) continue;
ch = chp - base64_table;
switch(i % 4) {
case 0:
result[j] = (unsigned char)(ch << 2);
break;
case 1:
result[j++] |= ch >> 4;
result[j] = (unsigned char)((ch & 0x0f) << 4);
break;
case 2:
result[j++] |= ch >>2;
result[j] = (unsigned char)((ch & 0x03) << 6);
break;
case 3:
result[j++] |= ch;
break;
}
i++;
}
k = j;
/* mop things up if we ended on a boundary */
if (ch == base64_pad) {
switch(i % 4) {
case 0:
case 1:
delete [] result;
return NULL;
case 2:
k++;
case 3:
result[k++] = 0;
}
}
if(ret_length) {
*ret_length = j;
}
result[k] = '\0';
return result;
}
void base64_free(unsigned char* data)
{
delete[] data;
}
