/*

cencoder.c - c source to a base64 encoding algorithm implementation

This is part of the libb64 project, and has been placed in the public domain.

For details, see http://sourceforge.net/projects/libb64

*/

#include "cencode.h" // changed from <B64/cencode.h>

static const int CHARS_PER_LINE = 72;

#ifdef _MSC_VER

#pragma warning(push)

#pragma warning(disable : 4244)

#endif // _MSC_VER

void base64_init_encodestate(base64_encodestate* state_in)

{

  state_in->step = step_A;

  state_in->result = 0;

  state_in->stepcount = 0;

}

char base64_encode_value(char value_in)

{

  static const char* encoding = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

  if (value_in > 63) return '=';

  return encoding[(int)value_in];

}

int base64_encode_block(const char* plaintext_in, int length_in, char* code_out, base64_encodestate* state_in)

{

  const char* plainchar = plaintext_in;

  const char* const plaintextend = plaintext_in + length_in;

  char* codechar = code_out;

  char result;

  char fragment;

  result = state_in->result;

  switch (state_in->step)

  {

    while (1)

    {

  case step_A:

      if (plainchar == plaintextend)

      {

        state_in->result = result;

        state_in->step = step_A;

        return (int)(codechar - code_out);

      }

      fragment = *plainchar++;

      result = (fragment & 0x0fc) >> 2;

      *codechar++ = base64_encode_value(result);

      result = (fragment & 0x003) << 4;

  case step_B:

      if (plainchar == plaintextend)

      {

        state_in->result = result;

        state_in->step = step_B;

        return (int)(codechar - code_out);

      }

      fragment = *plainchar++;

      result |= (fragment & 0x0f0) >> 4;

      *codechar++ = base64_encode_value(result);

      result = (fragment & 0x00f) << 2;

  case step_C:

      if (plainchar == plaintextend)

      {

        state_in->result = result;

        state_in->step = step_C;

        return (int)(codechar - code_out);

      }

      fragment = *plainchar++;

      result |= (fragment & 0x0c0) >> 6;

      *codechar++ = base64_encode_value(result);

      result  = (fragment & 0x03f) >> 0;

      *codechar++ = base64_encode_value(result);

      ++(state_in->stepcount);

      if (state_in->stepcount == CHARS_PER_LINE/4)

      {

        *codechar++ = '\n';

        state_in->stepcount = 0;

      }

    }

  }

  /* control should not reach here */

  return (int)(codechar - code_out);

}

int base64_encode_blockend(char* code_out, base64_encodestate* state_in)

{

  char* codechar = code_out;

  switch (state_in->step)

  {

  case step_B:

    *codechar++ = base64_encode_value(state_in->result);

    *codechar++ = '=';

    *codechar++ = '=';

    break;

  case step_C:

    *codechar++ = base64_encode_value(state_in->result);

    *codechar++ = '=';

    break;

  case step_A:

    break;

  }

  *codechar++ = '\n';

  return (int)(codechar - code_out);

}

#ifdef _MSC_VER

#pragma warning(pop)

#endif // _MSC_VER