/* Copyright (c) Dovecot authors, see top-level COPYING file */

#include "lib.h"

#include "buffer.h"

#include "hex-binary.h"

#include "quoted-printable.h"

int quoted_printable_q_decode(const unsigned char *src, size_t src_size,

            buffer_t *dest)

{

  char hexbuf[3];

  size_t src_pos, next;

  bool errors = FALSE;

  hexbuf[2] = '\0';

  next = 0;

  for (src_pos = 0; src_pos < src_size; src_pos++) {

    if (src[src_pos] != '_' && src[src_pos] != '=')

      continue;

    buffer_append(dest, src + next, src_pos - next);

    next = src_pos;

    if (src[src_pos] == '_') {

      buffer_append_c(dest, ' ');

      next++;

      continue;

    }

    if (src_pos+2 >= src_size)

      break;

    /* =<hex> */

    hexbuf[0] = (char) src[src_pos+1];

    hexbuf[1] = (char) src[src_pos+2];

    if (hex_to_binary(hexbuf, dest) == 0) {

      src_pos += 2;

      next = src_pos+1;

    } else {

      /* non-hex data, show as-is */

      errors = TRUE;

      next = src_pos;

    }

  }

  buffer_append(dest, src + next, src_size - next);

  return errors ? -1 : 0;

}