source: releases/0.4.0/src/reglookup.c @ 250

/*
 * A utility to read a Windows NT/2K/XP/2K3 registry file, using 
 * Gerald Carter''s regfio interface.
 *
 * Copyright (C) 2005-2007 Timothy D. Morgan
 * Copyright (C) 2002 Richard Sharpe, rsharpe@richardsharpe.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  
 *
 * $Id: reglookup.c 96 2007-03-29 01:41:33Z tim $
 */


#include <stdlib.h>
#include <sysexits.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <iconv.h>
#include "../include/regfi.h"
#include "../include/void_stack.h"

/* Globals, influenced by command line parameters */
bool print_verbose = false;
bool print_security = false;
bool print_header = true;
bool path_filter_enabled = false;
bool type_filter_enabled = false;
char* path_filter = NULL;
int type_filter;
char* registry_file = NULL;

/* Other globals */
const char* key_special_chars = ",\"\\/";
const char* subfield_special_chars = ",\"\\|";
const char* common_special_chars = ",\"\\";

iconv_t conv_desc;


void bailOut(int code, char* message)
{
  fprintf(stderr, message);
  exit(code);
}


/* Returns a newly malloc()ed string which contains original buffer,
 * except for non-printable or special characters are quoted in hex
 * with the syntax '\xQQ' where QQ is the hex ascii value of the quoted
 * character.  A null terminator is added, since only ascii, not binary,
 * is returned.
 */
static char* quote_buffer(const unsigned char* str, 
                          unsigned int len, const char* special)
{
  unsigned int i, added_len;
  unsigned int num_written = 0;

  unsigned int buf_len = sizeof(char)*(len+1);
  char* ret_val = malloc(buf_len);
  char* tmp_buf;

  if(ret_val == NULL)
    return NULL;

  for(i=0; i<len; i++)
  {
    if(buf_len <= (num_written+5))
    {
      /* Expand the buffer by the memory consumption rate seen so far 
       * times the amount of input left to process.  The expansion is bounded 
       * below by a minimum safety increase, and above by the maximum possible 
       * output string length.  This should minimize both the number of 
       * reallocs() and the amount of wasted memory.
       */
      added_len = (len-i)*num_written/(i+1);
      if((buf_len+added_len) > (len*4+1))
        buf_len = len*4+1;
      else
      {
        if (added_len < 5)
          buf_len += 5;
        else
          buf_len += added_len;
      }

      tmp_buf = realloc(ret_val, buf_len);
      if(tmp_buf == NULL)
      {
        free(ret_val);
        return NULL;
      }
      ret_val = tmp_buf;
    }
    
    if(str[i] < 32 || str[i] > 126 || strchr(special, str[i]) != NULL)
    {
      num_written += snprintf(ret_val + num_written, buf_len - num_written,
                              "\\x%.2X", str[i]);
    }
    else
      ret_val[num_written++] = str[i];
  }
  ret_val[num_written] = '\0';

  return ret_val;
}


/* Returns a newly malloc()ed string which contains original string, 
 * except for non-printable or special characters are quoted in hex
 * with the syntax '\xQQ' where QQ is the hex ascii value of the quoted
 * character.
 */
static char* quote_string(const char* str, const char* special)
{
  unsigned int len;

  if(str == NULL)
    return NULL;

  len = strlen(str);
  return quote_buffer((const unsigned char*)str, len, special);
}


/*
 * Convert from UTF-16LE to ASCII.  Accepts a Unicode buffer, uni, and
 * it's length, uni_max.  Writes ASCII to the buffer ascii, whose size
 * is ascii_max.  Writes at most (ascii_max-1) bytes to ascii, and null
 * terminates the string.  Returns the length of the string stored in
 * ascii.  On error, returns a negative errno code.
 */
static int uni_to_ascii(unsigned char* uni, char* ascii, 
                        unsigned int uni_max, unsigned int ascii_max)
{
  char* inbuf = (char*)uni;
  char* outbuf = ascii;
  size_t in_len = (size_t)uni_max;
  size_t out_len = (size_t)(ascii_max-1);
  int ret;

  /* Set up conversion descriptor. */
  conv_desc = iconv_open("US-ASCII", "UTF-16LE");

  ret = iconv(conv_desc, &inbuf, &in_len, &outbuf, &out_len);
  if(ret == -1)
  {
    iconv_close(conv_desc);
    return -errno;
  }
  *outbuf = '\0';

  iconv_close(conv_desc);  
  return strlen(ascii);
}


/*
 * Convert a data value to a string for display.  Returns NULL on error,
 * and the string to display if there is no error, or a non-fatal
 * error.  On any error (fatal or non-fatal) occurs, (*error_msg) will
 * be set to a newly allocated string, containing an error message.  If
 * a memory allocation failure occurs while generating the error
 * message, both the return value and (*error_msg) will be NULL.  It
 * is the responsibility of the caller to free both a non-NULL return
 * value, and a non-NULL (*error_msg).
 */
static char* data_to_ascii(unsigned char *datap, uint32 len, uint32 type, 
                           char** error_msg)
{
  char* asciip;
  char* ascii;
  unsigned char* cur_str;
  char* cur_ascii;
  char* cur_quoted;
  char* tmp_err;
  const char* str_type;
  uint32 i;
  uint32 cur_str_len;
  uint32 ascii_max, cur_str_max;
  uint32 str_rem, cur_str_rem, alen;
  int ret_err;
  unsigned short num_nulls;

  *error_msg = NULL;

  switch (type) 
  {
  case REG_SZ:
  case REG_EXPAND_SZ:
    /* REG_LINK is a symbolic link, stored as a unicode string. */
  case REG_LINK:
    ascii_max = sizeof(char)*(len+1);
    ascii = malloc(ascii_max);
    if(ascii == NULL)
      return NULL;
    
    /* Sometimes values have binary stored in them.  If the unicode
     * conversion fails, just quote it raw.
     */
    ret_err = uni_to_ascii(datap, ascii, len, ascii_max);
    if(ret_err < 0)
    {
      tmp_err = strerror(-ret_err);
      str_type = regfi_type_val2str(type);
      *error_msg = (char*)malloc(65+strlen(str_type)+strlen(tmp_err)+1);
      if(*error_msg == NULL)
      {
        free(ascii);
        return NULL;
      }
      sprintf(*error_msg, "Unicode conversion failed on %s field; "
               "printing as binary.  Error: %s", str_type, tmp_err);
      
      cur_quoted = quote_buffer(datap, len, common_special_chars);
    }
    else
      cur_quoted = quote_string(ascii, common_special_chars);
    free(ascii);
    if(cur_quoted == NULL)
    {
      *error_msg = (char*)malloc(27+1);
      if(*error_msg != NULL)
        strcpy(*error_msg, "Buffer could not be quoted.");
    }
    return cur_quoted;
    break;

  case REG_DWORD:
    ascii_max = sizeof(char)*(8+2+1);
    ascii = malloc(ascii_max);
    if(ascii == NULL)
      return NULL;

    snprintf(ascii, ascii_max, "0x%.2X%.2X%.2X%.2X", 
             datap[0], datap[1], datap[2], datap[3]);
    return ascii;
    break;

  case REG_DWORD_BE:
    ascii_max = sizeof(char)*(8+2+1);
    ascii = malloc(ascii_max);
    if(ascii == NULL)
      return NULL;

    snprintf(ascii, ascii_max, "0x%.2X%.2X%.2X%.2X", 
             datap[3], datap[2], datap[1], datap[0]);
    return ascii;
    break;

  case REG_QWORD:
    ascii_max = sizeof(char)*(16+2+1);
    ascii = malloc(ascii_max);
    if(ascii == NULL)
      return NULL;

    snprintf(ascii, ascii_max, "0x%.2X%.2X%.2X%.2X%.2X%.2X%.2X%.2X",
             datap[7], datap[6], datap[5], datap[4],
             datap[3], datap[2], datap[1], datap[0]);
    return ascii;
    break;
    

  /* XXX: this MULTI_SZ parser is pretty inefficient.  Should be
   *      redone with fewer malloc calls and better string concatenation. 
   */
  case REG_MULTI_SZ:
    ascii_max = sizeof(char)*(len*4+1);
    cur_str_max = sizeof(char)*(len+1);
    cur_str = malloc(cur_str_max);
    cur_ascii = malloc(cur_str_max);
    ascii = malloc(ascii_max);
    if(ascii == NULL || cur_str == NULL || cur_ascii == NULL)
      return NULL;

    /* Reads until it reaches 4 consecutive NULLs, 
     * which is two nulls in unicode, or until it reaches len, or until we
     * run out of buffer.  The latter should never happen, but we shouldn't
     * trust our file to have the right lengths/delimiters.
     */
    asciip = ascii;
    num_nulls = 0;
    str_rem = ascii_max;
    cur_str_rem = cur_str_max;
    cur_str_len = 0;

    for(i=0; (i < len) && str_rem > 0; i++)
    {
      *(cur_str+cur_str_len) = *(datap+i);
      if(*(cur_str+cur_str_len) == 0)
        num_nulls++;
      else
        num_nulls = 0;
      cur_str_len++;

      if(num_nulls == 2)
      {
        ret_err = uni_to_ascii(cur_str, cur_ascii, cur_str_len-1, cur_str_max);
        if(ret_err < 0)
        {
          /* XXX: should every sub-field error be enumerated? */
          if(*error_msg == NULL)
          {
            tmp_err = strerror(-ret_err);
            *error_msg = (char*)malloc(90+strlen(tmp_err)+1);
            if(*error_msg == NULL)
            {
              free(cur_str);
              free(cur_ascii);
              free(ascii);
              return NULL;
            }
            sprintf(*error_msg, "Unicode conversion failed on at least one "
                    "MULTI_SZ sub-field; printing as binary.  Error: %s",
                    tmp_err);
          }
          cur_quoted = quote_buffer(cur_str, cur_str_len-1, 
                                    subfield_special_chars);
        }
        else
          cur_quoted = quote_string(cur_ascii, subfield_special_chars);

        alen = snprintf(asciip, str_rem, "%s", cur_quoted);
        asciip += alen;
        str_rem -= alen;
        free(cur_quoted);

        if(*(datap+i+1) == 0 && *(datap+i+2) == 0)
          break;
        else
        {
          if(str_rem > 0)
          {
            asciip[0] = '|';
            asciip[1] = '\0';
            asciip++;
            str_rem--;
          }
          memset(cur_str, 0, cur_str_max);
          cur_str_len = 0;
          num_nulls = 0;
          /* To eliminate leading nulls in subsequent strings. */
          i++;
        }
      }
    }
    *asciip = 0;
    free(cur_str);
    free(cur_ascii);
    return ascii;
    break;

  /* XXX: Dont know what to do with these yet, just print as binary... */
  default:
    fprintf(stderr, "WARNING: Unrecognized registry data type (0x%.8X); quoting as binary.\n", type);
    
  case REG_NONE:
  case REG_RESOURCE_LIST:
  case REG_FULL_RESOURCE_DESCRIPTOR:
  case REG_RESOURCE_REQUIREMENTS_LIST:

  case REG_BINARY:
    return quote_buffer(datap, len, common_special_chars);
    break;
  }

  return NULL;
}


/* XXX: Each chunk must be unquoted after it is split out. 
 *      Quoting syntax may need to be standardized and pushed into the API 
 *      to deal with this issue and others.
 */
char** splitPath(const char* s)
{
  char** ret_val;
  const char* cur = s;
  char* next = NULL;
  char* copy;
  uint32 ret_cur = 0;

  ret_val = (char**)malloc((REGF_MAX_DEPTH+1+1)*sizeof(char**));
  if (ret_val == NULL)
    return NULL;
  ret_val[0] = NULL;

  /* We return a well-formed, 0-length, path even when input is icky. */
  if (s == NULL)
    return ret_val;
  
  while((next = strchr(cur, '/')) != NULL)
  {
    if ((next-cur) > 0)
    {
      copy = (char*)malloc((next-cur+1)*sizeof(char));
      if(copy == NULL)
        bailOut(EX_OSERR, "ERROR: Memory allocation problem.\n");
          
      memcpy(copy, cur, next-cur);
      copy[next-cur] = '\0';
      ret_val[ret_cur++] = copy;
      if(ret_cur < (REGF_MAX_DEPTH+1+1))
        ret_val[ret_cur] = NULL;
      else
        bailOut(EX_DATAERR, "ERROR: Registry maximum depth exceeded.\n");
    }
    cur = next+1;
  }

  /* Grab last element, if path doesn't end in '/'. */
  if(strlen(cur) > 0)
  {
    copy = strdup(cur);
    ret_val[ret_cur++] = copy;
    if(ret_cur < (REGF_MAX_DEPTH+1+1))
      ret_val[ret_cur] = NULL;
    else
      bailOut(EX_DATAERR, "ERROR: Registry maximum depth exceeded.\n");
  }

  return ret_val;
}


void freePath(char** path)
{
  uint32 i;

  if(path == NULL)
    return;

  for(i=0; path[i] != NULL; i++)
    free(path[i]);

  free(path);
}


/* Returns a quoted path from an iterator's stack */
/* XXX: Some way should be found to integrate this into regfi's API 
 *      The problem is that the escaping is sorta reglookup-specific.
 */
char* iter2Path(REGFI_ITERATOR* i)
{
  const REGFI_ITER_POSITION* cur;
  uint32 buf_left = 127;
  uint32 buf_len = buf_left+1;
  uint32 name_len = 0;
  uint32 grow_amt;
  char* buf;
  char* new_buf;
  char* name;
  const char* cur_name;
  void_stack_iterator* iter;
  
  buf = (char*)malloc((buf_len)*sizeof(char));
  if (buf == NULL)
    return NULL;
  buf[0] = '\0';

  iter = void_stack_iterator_new(i->key_positions);
  if (iter == NULL)
  {
    free(buf);
    return NULL;
  }

  /* skip root element */
  if(void_stack_size(i->key_positions) < 1)
  {
    buf[0] = '/';
    buf[1] = '\0';
    return buf;
  }
  cur = void_stack_iterator_next(iter);

  do
  {
    cur = void_stack_iterator_next(iter);
    if (cur == NULL)
      cur_name = i->cur_key->keyname;
    else
      cur_name = cur->nk->keyname;

    buf[buf_len-buf_left-1] = '/';
    buf_left -= 1;
    name = quote_string(cur_name, key_special_chars);
    name_len = strlen(name);
    if(name_len+1 > buf_left)
    {
      grow_amt = (uint32)(buf_len/2);
      buf_len += name_len+1+grow_amt-buf_left;
      if((new_buf = realloc(buf, buf_len)) == NULL)
      {
        free(buf);
        free(iter);
        return NULL;
      }
      buf = new_buf;
      buf_left = grow_amt + name_len + 1;
    }
    strncpy(buf+(buf_len-buf_left-1), name, name_len);
    buf_left -= name_len;
    buf[buf_len-buf_left-1] = '\0';
    free(name);
  } while(cur != NULL);

  return buf;
}


void printValue(const REGF_VK_REC* vk, char* prefix)
{
  char* quoted_value = NULL;
  char* quoted_name = NULL;
  char* conv_error = NULL;
  const char* str_type = NULL;
  uint32 size;
  uint8 tmp_buf[4];

  /* Thanks Microsoft for making this process so straight-forward!!! */
  /* XXX: this logic should be abstracted  and pushed into the regfi 
   *      interface.  This includes the size limits.
   */
  size = (vk->data_size & ~VK_DATA_IN_OFFSET);
  if(vk->data_size & VK_DATA_IN_OFFSET)
  {
    tmp_buf[0] = (uint8)((vk->data_off >> 3) & 0xFF);
    tmp_buf[1] = (uint8)((vk->data_off >> 2) & 0xFF);
    tmp_buf[2] = (uint8)((vk->data_off >> 1) & 0xFF);
    tmp_buf[3] = (uint8)(vk->data_off & 0xFF);
    if(size > 4)
    {
      fprintf(stderr, "WARNING: value stored in offset larger than 4. "
              "Truncating...\n");
      size = 4;
    }
    quoted_value = data_to_ascii(tmp_buf, 4, vk->type, &conv_error);
  }
  else
  {
    /* Microsoft's documentation indicates that "available memory" is 
     * the limit on value sizes.  Annoying.  We limit it to 1M which 
     * should rarely be exceeded, unless the file is corrupt or 
     * malicious. For more info, see:
     *   http://msdn2.microsoft.com/en-us/library/ms724872.aspx
     */
    if(size > VK_MAX_DATA_LENGTH)
    {
      fprintf(stderr, "WARNING: value data size %d larger than "
              "%d, truncating...\n", size, VK_MAX_DATA_LENGTH);
      size = VK_MAX_DATA_LENGTH;
    }

    quoted_value = data_to_ascii(vk->data, vk->data_size, 
                                 vk->type, &conv_error);
  }
  
  /* XXX: Sometimes value names can be NULL in registry.  Need to
   *      figure out why and when, and generate the appropriate output
   *      for that condition.
   */
  quoted_name = quote_string(vk->valuename, common_special_chars);
  if (quoted_name == NULL)
  {
    quoted_name = malloc(1*sizeof(char));
    if(quoted_name == NULL)
      bailOut(EX_OSERR, "ERROR: Could not allocate sufficient memory.\n");
    quoted_name[0] = '\0';
  }

  if(quoted_value == NULL)
  {
    if(conv_error == NULL)
      fprintf(stderr, "WARNING: Could not quote value for '%s/%s'.  "
              "Memory allocation failure likely.\n", prefix, quoted_name);
    else
      fprintf(stderr, "WARNING: Could not quote value for '%s/%s'.  "
              "Returned error: %s\n", prefix, quoted_name, conv_error);
  }
  /* XXX: should these always be printed? */
  else if(conv_error != NULL && print_verbose)
      fprintf(stderr, "VERBOSE: While quoting value for '%s/%s', "
              "warning returned: %s\n", prefix, quoted_name, conv_error);

  str_type = regfi_type_val2str(vk->type);
  if(print_security)
  {
    if(str_type == NULL)
      printf("%s/%s,0x%.8X,%s,,,,,\n", prefix, quoted_name,
             vk->type, quoted_value);
    else
      printf("%s/%s,%s,%s,,,,,\n", prefix, quoted_name,
             str_type, quoted_value);
  }
  else
  {
    if(str_type == NULL)
      printf("%s/%s,0x%.8X,%s,\n", prefix, quoted_name,
             vk->type, quoted_value);
    else
      printf("%s/%s,%s,%s,\n", prefix, quoted_name,
             str_type, quoted_value);
  }

  if(quoted_value != NULL)
    free(quoted_value);
  if(quoted_name != NULL)
    free(quoted_name);
  if(conv_error != NULL)
    free(conv_error);
}


void printValueList(REGFI_ITERATOR* i, char* prefix)
{
  const REGF_VK_REC* value;

  value = regfi_iterator_first_value(i);
  while(value != NULL)
  {
    if(!type_filter_enabled || (value->type == type_filter))
      printValue(value, prefix);
    value = regfi_iterator_next_value(i);
  }
}


void printKey(const REGF_NK_REC* k, char* full_path)
{
  static char empty_str[1] = "";
  char* owner = NULL;
  char* group = NULL;
  char* sacl = NULL;
  char* dacl = NULL;
  char mtime[20];
  time_t tmp_time[1];
  struct tm* tmp_time_s = NULL;

  *tmp_time = nt_time_to_unix(&k->mtime);
  tmp_time_s = gmtime(tmp_time);
  strftime(mtime, sizeof(mtime), "%Y-%m-%d %H:%M:%S", tmp_time_s);

  if(print_security)
  {
    owner = regfi_get_owner(k->sec_desc->sec_desc);
    group = regfi_get_group(k->sec_desc->sec_desc);
    sacl = regfi_get_sacl(k->sec_desc->sec_desc);
    dacl = regfi_get_dacl(k->sec_desc->sec_desc);
    if(owner == NULL)
      owner = empty_str;
    if(group == NULL)
      group = empty_str;
    if(sacl == NULL)
      sacl = empty_str;
    if(dacl == NULL)
      dacl = empty_str;

    printf("%s,KEY,,%s,%s,%s,%s,%s\n", full_path, mtime, 
           owner, group, sacl, dacl);

    if(owner != empty_str)
      free(owner);
    if(group != empty_str)
      free(group);
    if(sacl != empty_str)
      free(sacl);
    if(dacl != empty_str)
      free(dacl);
  }
  else
    printf("%s,KEY,,%s\n", full_path, mtime);
}


void printKeyTree(REGFI_ITERATOR* iter)
{
  const REGF_NK_REC* root = NULL;
  const REGF_NK_REC* cur = NULL;
  const REGF_NK_REC* sub = NULL;
  char* path = NULL;
  int key_type = regfi_type_str2val("KEY");
  bool print_this = true;

  root = cur = regfi_iterator_cur_key(iter);
  sub = regfi_iterator_first_subkey(iter);
  
  if(root == NULL)
    bailOut(EX_DATAERR, "ERROR: root cannot be NULL.\n");
  
  do
  {
    if(print_this)
    {
      path = iter2Path(iter);
      if(path == NULL)
        bailOut(EX_OSERR, "ERROR: Could not construct iterator's path.\n");
      
      if(!type_filter_enabled || (key_type == type_filter))
        printKey(cur, path);
      if(!type_filter_enabled || (key_type != type_filter))
        printValueList(iter, path);
      
      free(path);
    }
    
    if(sub == NULL)
    {
      if(cur != root)
      {
        /* We're done with this sub-tree, going up and hitting other branches. */
        if(!regfi_iterator_up(iter))
          bailOut(EX_DATAERR, "ERROR: could not traverse iterator upward.\n");
        
        cur = regfi_iterator_cur_key(iter);
        if(cur == NULL)
          bailOut(EX_DATAERR, "ERROR: unexpected NULL for key.\n");
        
        sub = regfi_iterator_next_subkey(iter);
      }
      print_this = false;
    }
    else
    { /* We have unexplored sub-keys.  
       * Let's move down and print this first sub-tree out. 
       */
      if(!regfi_iterator_down(iter))
        bailOut(EX_DATAERR, "ERROR: could not traverse iterator downward.\n");

      cur = sub;
      sub = regfi_iterator_first_subkey(iter);
      print_this = true;
    }
  } while(!((cur == root) && (sub == NULL)));

  if(print_verbose)
    fprintf(stderr, "VERBOSE: Finished printing key tree.\n");
}


/*
 * Returns 0 if path was not found.
 * Returns 1 if path was found as value.
 * Returns 2 if path was found as key.
 * Returns less than 0 on other error.
 */
int retrievePath(REGFI_ITERATOR* iter, char** path)
{
  const REGF_VK_REC* value;
  char* tmp_path_joined;
  const char** tmp_path;
  uint32 i;
  
  if(path == NULL)
    return -1;

  /* One extra for any value at the end, and one more for NULL */
  tmp_path = (const char**)malloc(sizeof(const char**)*(REGF_MAX_DEPTH+1+1));
  if(tmp_path == NULL)
    return -2;

  /* Strip any potential value name at end of path */
  for(i=0; 
      (path[i] != NULL) && (path[i+1] != NULL) 
        && (i < REGF_MAX_DEPTH+1+1);
      i++)
    tmp_path[i] = path[i];

  tmp_path[i] = NULL;

  if(print_verbose)
    fprintf(stderr, "VERBOSE: Attempting to retrieve specified path: %s\n",
            path_filter);

  /* Special check for '/' path filter */
  if(path[0] == NULL)
  {
    if(print_verbose)
      fprintf(stderr, "VERBOSE: Found final path element as root key.\n");
    return 2;
  }

  if(!regfi_iterator_walk_path(iter, tmp_path))
  {
    free(tmp_path);
    return 0;
  }

  if(regfi_iterator_find_value(iter, path[i]))
  {
    if(print_verbose)
      fprintf(stderr, "VERBOSE: Found final path element as value.\n");

    value = regfi_iterator_cur_value(iter);
    tmp_path_joined = iter2Path(iter);

    if((value == NULL) || (tmp_path_joined == NULL))
      bailOut(EX_OSERR, "ERROR: Unexpected error before printValue.\n");

    printValue(value, tmp_path_joined);

    free(tmp_path);
    free(tmp_path_joined);
    return 1;
  }
  else if(regfi_iterator_find_subkey(iter, path[i]))
  {
    if(print_verbose)
      fprintf(stderr, "VERBOSE: Found final path element as key.\n");

    if(!regfi_iterator_down(iter))
      bailOut(EX_DATAERR, "ERROR: Unexpected error on traversing path filter key.\n");

    return 2;
  }

  if(print_verbose)
    fprintf(stderr, "VERBOSE: Could not find last element of path.\n");

  return 0;
}


static void usage(void)
{
  fprintf(stderr, "Usage: reglookup [-v] [-s]"
          " [-p <PATH_FILTER>] [-t <TYPE_FILTER>]"
          " <REGISTRY_FILE>\n");
  fprintf(stderr, "Version: 0.4.0\n");
  fprintf(stderr, "Options:\n");
  fprintf(stderr, "\t-v\t sets verbose mode.\n");
  fprintf(stderr, "\t-h\t enables header row. (default)\n");
  fprintf(stderr, "\t-H\t disables header row.\n");
  fprintf(stderr, "\t-s\t enables security descriptor output.\n");
  fprintf(stderr, "\t-S\t disables security descriptor output. (default)\n");
  fprintf(stderr, "\t-p\t restrict output to elements below this path.\n");
  fprintf(stderr, "\t-t\t restrict results to this specific data type.\n");
  fprintf(stderr, "\n");
}


int main(int argc, char** argv)
{
  char** path = NULL;
  REGF_FILE* f;
  REGFI_ITERATOR* iter;
  int retr_path_ret;
  uint32 argi, arge;

  /* Process command line arguments */
  if(argc < 2)
  {
    usage();
    bailOut(EX_USAGE, "ERROR: Requires at least one argument.\n");
  }
  
  arge = argc-1;
  for(argi = 1; argi < arge; argi++)
  {
    if (strcmp("-p", argv[argi]) == 0)
    {
      if(++argi >= arge)
      {
        usage();
        bailOut(EX_USAGE, "ERROR: '-p' option requires parameter.\n");
      }
      if((path_filter = strdup(argv[argi])) == NULL)
        bailOut(EX_OSERR, "ERROR: Memory allocation problem.\n");

      path_filter_enabled = true;
    }
    else if (strcmp("-t", argv[argi]) == 0)
    {
      if(++argi >= arge)
      {
        usage();
        bailOut(EX_USAGE, "ERROR: '-t' option requires parameter.\n");
      }
      if((type_filter = regfi_type_str2val(argv[argi])) < 0)
      {
        fprintf(stderr, "ERROR: Invalid type specified: %s.\n", argv[argi]);
        bailOut(EX_USAGE, "");
      }
      type_filter_enabled = true;
    }
    else if (strcmp("-h", argv[argi]) == 0)
      print_header = true;
    else if (strcmp("-H", argv[argi]) == 0)
      print_header = false;
    else if (strcmp("-s", argv[argi]) == 0)
      print_security = true;
    else if (strcmp("-S", argv[argi]) == 0)
      print_security = false;
    else if (strcmp("-v", argv[argi]) == 0)
      print_verbose = true;
    else
    {
      usage();
      fprintf(stderr, "ERROR: Unrecognized option: %s\n", argv[argi]);
      bailOut(EX_USAGE, "");
    }
  }
  if((registry_file = strdup(argv[argi])) == NULL)
    bailOut(EX_OSERR, "ERROR: Memory allocation problem.\n");

  f = regfi_open(registry_file);
  if(f == NULL)
  {
    fprintf(stderr, "ERROR: Couldn't open registry file: %s\n", registry_file);
    bailOut(EX_NOINPUT, "");
  }

  iter = regfi_iterator_new(f);
  if(iter == NULL)
    bailOut(EX_OSERR, "ERROR: Couldn't create registry iterator.\n");

  if(print_header)
  {
    if(print_security)
      printf("PATH,TYPE,VALUE,MTIME,OWNER,GROUP,SACL,DACL\n");
    else
      printf("PATH,TYPE,VALUE,MTIME\n");
  }

  if(path_filter_enabled && path_filter != NULL)
    path = splitPath(path_filter);

  if(path != NULL)
  {
    retr_path_ret = retrievePath(iter, path);
    freePath(path);

    if(retr_path_ret == 0)
      fprintf(stderr, "WARNING: specified path not found.\n");
    else if (retr_path_ret == 2)
      printKeyTree(iter);
    else if(retr_path_ret < 0)
    {
      fprintf(stderr, "ERROR: retrievePath() returned %d.\n", 
              retr_path_ret);
      bailOut(EX_DATAERR,"ERROR: Unknown error occurred in retrieving path.\n");
    }
  }
  else
    printKeyTree(iter);

  regfi_iterator_free(iter);
  regfi_close(f);

  return 0;
}