// aLen 为 aSrc 的长度， aDest 所指的缓冲区必须至少为 aLen 的 1.33 倍！！！
// 返回 aDest 的长度
unsigned int Base64Encode( char * const aDest, const unsigned char * aSrc, unsigned int aLen )
{
char * p = aDest;
unsigned int i;
unsigned char t;
for ( i = 0; i < aLen; i++ )
{
switch ( i % 3 )
{
case 0 :
*p++ = Base2Chr( *aSrc >> 2 );
t = ( *aSrc++ << 4 ) & 0x3F;
break;
case 1 :
*p++ = Base2Chr( t | ( *aSrc >> 4 ) );
t = ( *aSrc++ << 2 ) & 0x3F;
break;
case 2 :
*p++ = Base2Chr( t | ( *aSrc >> 6 ) );
*p++ = Base2Chr( *aSrc++ );
break;
}
}
if ( aLen % 3 != 0 )
{
*p++ = Base2Chr( t );
if ( aLen % 3 == 1 )
*p++ = '=';
*p++ = '=';
}
*p = 0; // aDest is an ASCIIZ string
return (unsigned int)( p - aDest ); // exclude the end of zero
}
// base64加密
int CYTSocket::Base64Encode(const char * inbuf, char * outbuf)
{
unsigned int x, y, z;
unsigned int i, j;
unsigned char buf[3];
x = strlen(inbuf)/3;
y = strlen(inbuf)%3;
i = 0;
j = 0;
for(z=0; z<x; z++)
{
outbuf[i] = Base2Chr(inbuf[j]>>2);
outbuf[i+1] = Base2Chr((inbuf[j] & 0x03)<<4 | inbuf[j+1]>>4);
outbuf[i+2] = Base2Chr((inbuf[j+1] & 0x0F)<<2 | inbuf[j+2]>>6);
outbuf[i+3] = Base2Chr(inbuf[j+2] & 0x3F);
i += 4;
j += 3;
}
if(y != 0)
{
buf[0] = 0x00;
buf[1] = 0x00;
buf[2] = 0x00;
for(z=0; z<y; z++)
{
buf[z] = inbuf[j+z];
}
outbuf[i] = Base2Chr(buf[0]>>2);
outbuf[i+1] = Base2Chr((buf[0] & 0x03)<<4 | buf[1]>>4);
outbuf[i+2] = Base2Chr((buf[1] & 0x0F)<<2 | buf[2]>>6);
outbuf[i+3] = Base2Chr(buf[2] & 0x3F);
i += 4;
for(z=0; z<3-y; z++)
{
outbuf[i-z-1] = '=';
}
}