GitHub Viewer
// Simple Base64 code
// (c) Copyright 2010 MCQN Ltd.
// Released under Apache License, version 2.0
#include "b64.h"
/* Simple test program
#include
void main()
{
char* in = "amcewen";
char out[22];
b64_encode(in, 15, out, 22);
out[21] = '\0';
printf(out);
}
*/
int b64_encode(const unsigned char* aInput, int aInputLen, unsigned char* aOutput, int aOutputLen)
{
// Work out if we've got enough space to encode the input
// Every 6 bits of input becomes a byte of output
if (aOutputLen < (aInputLen*8)/6)
{
// FIXME Should we return an error here, or just the length
return (aInputLen*8)/6;
}
// If we get here we've got enough space to do the encoding
const char* b64_dictionary = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
if (aInputLen == 3)
{
aOutput[0] = b64_dictionary[aInput[0] >> 2];
aOutput[1] = b64_dictionary[(aInput[0] & 0x3)4)];
aOutput[2] = b64_dictionary[(aInput[1]&0x0F)6)];
aOutput[3] = b64_dictionary[aInput[2]&0x3F];
}
else if (aInputLen == 2)
{
aOutput[0] = b64_dictionary[aInput[0] >> 2];
aOutput[1] = b64_dictionary[(aInput[0] & 0x3)4)];
aOutput[2] = b64_dictionary[(aInput[1]&0x0F) 2];
aOutput[1] = b64_dictionary[(aInput[0] & 0x3)