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/* wptWipeFile.cpp - Secure file removal |
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* Copyright (C) 2001-2005 Timo Schulz |
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* Copyright (C) 2000 Matt Gauthier |
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* |
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* WinPT software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* WinPT is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with WinPT; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA |
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* |
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************************************************************************** |
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* This code based on the sunlink.c file from the SRM project, but * |
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* it was heavily modified to work with W32 and with added GCRYPT * |
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* support for gathering random bytes. * |
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* * |
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* The original code was placed under the GNU Lesser Public License, * |
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* even so I decide to put this file under the GNU General Public License.* |
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************************************************************************** |
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*/ |
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|
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#include <windows.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <sys/stat.h> |
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#include <string.h> |
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#include <ctype.h> |
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#include <direct.h> |
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|
| 37 |
#include "openpgp.h" |
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#include "wptW32API.h" |
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#include "wptErrors.h" |
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#include "wptTypes.h" |
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|
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|
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typedef unsigned __int64 DDWORD; |
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|
| 45 |
typedef struct { |
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HANDLE fd; |
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DDWORD filesize; |
| 48 |
DDWORD offset; |
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BYTE *buffer; |
| 50 |
DWORD buffsize; |
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const char *name; |
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int n_passes; |
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} wipe_context_s; |
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|
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|
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void (*progress_cb) (void *, DDWORD, DDWORD); |
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static void *progress_cb_value = NULL; |
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|
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void (*unlink_cb)(void *, const char *, int, unsigned, unsigned) = NULL; |
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static void *unlink_cb_value = NULL; |
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|
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static void |
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overwrite (wipe_context_s * ctx) |
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{ |
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DDWORD blocks = 0, mod = 0; |
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DWORD nwritten = 0; |
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LONG size_high = 0; |
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|
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blocks = ctx->filesize / ctx->buffsize; |
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mod = ctx->filesize % ctx->buffsize; |
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SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN); |
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while (blocks--) { |
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if (!WriteFile (ctx->fd, ctx->buffer, ctx->buffsize, &nwritten, NULL)) |
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break; |
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ctx->offset += nwritten; |
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if (unlink_cb) |
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unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset, |
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(unsigned)ctx->filesize*ctx->n_passes); |
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} |
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if (mod) { |
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WriteFile (ctx->fd, ctx->buffer, (DWORD)mod, &nwritten, NULL); |
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ctx->offset += nwritten; |
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if (unlink_cb) |
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unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset, |
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(unsigned)ctx->filesize*ctx->n_passes); |
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} |
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FlushFileBuffers (ctx->fd); |
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SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN); |
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} /* overwrite */ |
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|
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|
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static void |
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randomize_buffer (byte * buf, size_t bufsize, int level) |
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{ |
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const int blocksize = 512; |
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int blocks = bufsize / blocksize; |
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int mod = bufsize % blocksize; |
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|
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while (blocks--) { |
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gpg_randomize (buf, blocksize, level); |
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buf += blocksize; |
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} |
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if (mod) |
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gpg_randomize (buf, mod, level); |
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} /* randomize_buffer */ |
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|
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|
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static void |
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overwrite_random (int npasses, wipe_context_s * ctx) |
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{ |
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int i; |
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|
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for (i = 0; i < npasses; i++) { |
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randomize_buffer (ctx->buffer, ctx->buffsize, 0); |
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overwrite (ctx); |
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} |
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} /* overwrite_random */ |
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|
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|
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static void |
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overwrite_byte (int byte, wipe_context_s * ctx) |
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{ |
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memset (ctx->buffer, byte, ctx->buffsize); |
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overwrite (ctx); |
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} /* overwrite_byte */ |
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|
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|
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static void |
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overwrite_bytes (int byte1, int byte2, int byte3, wipe_context_s * ctx) |
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{ |
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DWORD i; |
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|
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memset (ctx->buffer, byte1, ctx->buffsize); |
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for (i = 1; i < ctx->buffsize; i += 3) { |
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ctx->buffer[i] = byte2; |
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ctx->buffer[i+1] = byte3; |
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} |
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overwrite (ctx); |
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} /* overwrite_bytes */ |
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|
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|
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/** |
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* For the case the file is not a regular file (this is true for |
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* devices or directories) this function tries to rename the file |
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* to random pattern and then it will be delete (without random!). |
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**/ |
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int |
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rename_unlink (const char * path) |
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{ |
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struct stat statbuf; |
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char * new_name = NULL, * p = NULL, c; |
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int i = 0, rc = 0; |
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int is_dir = 0; |
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|
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if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY) |
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is_dir = 1; |
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|
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new_name = new char[strlen (path)+15]; |
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if (!new_name) |
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BUG (0); |
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|
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strcpy (new_name, path); |
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p = strrchr (new_name, '\\'); |
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if (p != NULL) { |
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p++; |
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*p = '\0'; |
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} |
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else |
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p = new_name; |
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do { |
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while (i < 14) { |
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c = gpg_random_char (1); |
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*p = c; |
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p++; |
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i++; |
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} |
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*p = '\0'; |
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} while (stat (new_name, &statbuf) == 0); |
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|
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if (rename (path, new_name) == -1) { |
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rc = WPTERR_FILE_READ; |
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goto leave; |
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} |
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if (is_dir && RemoveDirectory (new_name) == FALSE) |
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rc = WPTERR_FILE_REMOVE; |
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else if (!DeleteFile (new_name)) |
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rc = WPTERR_FILE_REMOVE; |
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|
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leave: |
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free_if_alloc (new_name); |
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return rc; |
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} /* rename_unlink */ |
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|
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|
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static __int64 |
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GetFileSize64 (const char * path) |
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{ |
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FILE *fp = fopen (path, "r"); |
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if (fp) { |
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struct _stati64 statbuf; |
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_fstati64 (fileno (fp), &statbuf); |
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fclose (fp); |
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return statbuf.st_size; |
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} |
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return -1; |
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} /* GetFileSize64 */ |
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|
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|
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static int |
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_secure_unlink (const char * path, int mode, HANDLE *r_fd) |
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{ |
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wipe_context_s ctx; |
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LONG size_high = 0; |
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|
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if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY) |
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return rename_unlink (path); |
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|
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memset (&ctx, 0, sizeof (ctx)); |
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ctx.name = path; |
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ctx.buffsize = 16384; |
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ctx.buffer = new byte[ctx.buffsize]; |
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if (!ctx.buffer) |
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BUG (0); |
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|
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ctx.filesize = GetFileSize64 (path); |
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if (!ctx.filesize) { |
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free_if_alloc (ctx.buffer); |
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return WPTERR_FILE_ZERO; |
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} |
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|
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ctx.fd = CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, |
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OPEN_ALWAYS, 0, NULL); |
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if (ctx.fd == INVALID_HANDLE_VALUE) { |
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free_if_alloc (ctx.buffer); |
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return WPTERR_FILE_OPEN; |
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} |
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else if (r_fd) |
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*r_fd = ctx.fd; |
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|
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gpg_quick_random_gen (1); |
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if (unlink_cb) |
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unlink_cb (unlink_cb_value, ctx.name, 0, 0, 0); |
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|
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switch (mode) { |
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case WIPE_MODE_FAST: |
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ctx.n_passes = 1; |
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overwrite_random (1, &ctx); |
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break; |
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|
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case WIPE_MODE_SIMPLE: |
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ctx.n_passes = 2; |
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overwrite_random (2, &ctx); |
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break; |
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|
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case WIPE_MODE_DOD: |
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ctx.n_passes = 5; |
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overwrite_random (1, &ctx); |
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overwrite_byte ((~1) & 0xFF, &ctx); |
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overwrite_random (1, &ctx); |
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overwrite_byte ((~4) & 0xFF, &ctx); |
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overwrite_random (1, &ctx); |
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break; |
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|
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case WIPE_MODE_GUTMANN: |
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ctx.n_passes = 39; |
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overwrite_random (4, &ctx); |
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overwrite_byte( 0x55, &ctx ); |
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overwrite_byte ( 0xAA, &ctx ); |
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overwrite_bytes( 0x92, 0x49, 0x24, &ctx ); |
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overwrite_bytes( 0x49, 0x24, 0x92, &ctx ); |
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overwrite_bytes( 0x24, 0x92, 0x49, &ctx ); |
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overwrite_byte( 0x00, &ctx ); |
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overwrite_byte( 0x11, &ctx ); |
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overwrite_byte( 0x22, &ctx ); |
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overwrite_byte( 0x33, &ctx ); |
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overwrite_byte( 0x44, &ctx ); |
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overwrite_byte( 0x55, &ctx ); |
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overwrite_byte( 0x66, &ctx ); |
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overwrite_byte( 0x77, &ctx ); |
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overwrite_byte( 0x88, &ctx ); |
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overwrite_byte( 0x99, &ctx ); |
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overwrite_byte( 0xAA, &ctx ); |
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overwrite_byte( 0xBB, &ctx ); |
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overwrite_byte( 0xCC, &ctx ); |
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overwrite_byte( 0xDD, &ctx ); |
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overwrite_byte( 0xEE, &ctx ); |
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overwrite_byte( 0xFF, &ctx ); |
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overwrite_bytes( 0x92, 0x49, 0x24, &ctx ); |
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overwrite_bytes( 0x49, 0x24, 0x92, &ctx ); |
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overwrite_bytes( 0x24, 0x92, 0x49, &ctx ); |
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overwrite_bytes( 0x6D, 0xB6, 0xDB, &ctx ); |
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overwrite_bytes( 0xB6, 0xDB, 0x6D, &ctx ); |
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overwrite_bytes( 0xDB, 0x6D, 0xB6, &ctx ); |
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overwrite_random( 4, &ctx ); |
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break; |
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} |
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|
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/* Set file length to zero so allocated clusters cannot be trailed */ |
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SetFilePointer (ctx.fd, 0, &size_high, FILE_BEGIN); |
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SetEndOfFile (ctx.fd); |
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CloseHandle (ctx.fd); |
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|
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memset (ctx.buffer, 0, ctx.buffsize); /* burn the last evidence */ |
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free_if_alloc (ctx.buffer); |
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|
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return rename_unlink (path); |
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} |
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|
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int |
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secure_unlink (const char *path, int mode) |
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{ |
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return _secure_unlink (path, mode, NULL); |
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} /* secure_unlink */ |
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|
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|
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|
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void |
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secure_unlink_set_cb (void (*cb)(void *, const char *, int, unsigned, unsigned), |
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void *cb_value) |
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{ |
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unlink_cb = cb; |
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unlink_cb_value = cb_value; |
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} /* secure_unlink_set_cb */ |
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|
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|
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/* Windows 98 - Q188074 */ |
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#define REGISTRY_FILESYSTEM "System\\CurrentControlSet\\Control\\FileSystem" |
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#define REGISTRY_LOWDISKSPACE "DisableLowDiskSpaceBroadcast" |
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|
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|
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/* disables the annoying warning Windows 98 displays when disk space is low */ |
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static void |
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handle_lowdiskspace_notify( const char * drive, int disable ) |
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{ |
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OSVERSIONINFO ov; |
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HKEY key; |
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DWORD n; |
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|
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memset( &ov, 0, sizeof ov ); |
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ov.dwOSVersionInfoSize = sizeof ov; |
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GetVersionEx( &ov ); |
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if( ov.dwPlatformId == VER_PLATFORM_WIN32_NT ) |
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return; |
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|
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if( disable ) { |
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unsigned newi = (1 << (toupper((unsigned)drive) - (unsigned)'A')); |
| 347 |
if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) { |
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n = sizeof newi; |
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RegSetValue( key, REGISTRY_LOWDISKSPACE, REG_DWORD, (LPCTSTR)newi, n ); |
| 350 |
RegCloseKey( key ); |
| 351 |
} |
| 352 |
} |
| 353 |
else { |
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if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) { |
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RegDeleteKey( key, REGISTRY_LOWDISKSPACE ); |
| 356 |
RegCloseKey( key ); |
| 357 |
} |
| 358 |
} |
| 359 |
} /* handle_lowdiskspace_notify */ |
| 360 |
|
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|
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int |
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wipe_freespace (const char * drive, HANDLE *r_fd, |
| 364 |
void (*cb)(void *, DDWORD, DDWORD), void * cb_value) |
| 365 |
{ |
| 366 |
ULARGE_INTEGER caller, total, frees; |
| 367 |
LONG hpart=0; |
| 368 |
HANDLE fd; |
| 369 |
int disktyp = GetDriveType (drive); |
| 370 |
int rc; |
| 371 |
char * file; |
| 372 |
|
| 373 |
if (disktyp != DRIVE_FIXED && disktyp != DRIVE_REMOVABLE) |
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return -1; |
| 375 |
if (!GetDiskFreeSpaceEx (drive, &caller, &total, &frees)) |
| 376 |
return -1; |
| 377 |
handle_lowdiskspace_notify (drive, 1); |
| 378 |
|
| 379 |
if (!frees.LowPart) |
| 380 |
return WPTERR_FILE_ZERO; |
| 381 |
file = new char[strlen (drive)+8]; |
| 382 |
if (!file) |
| 383 |
BUG (0); |
| 384 |
sprintf (file, "%stemp_winpt.tmp", drive); |
| 385 |
fd = CreateFile (file, |
| 386 |
GENERIC_READ|GENERIC_WRITE, |
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FILE_SHARE_READ|FILE_SHARE_WRITE, |
| 388 |
NULL, CREATE_ALWAYS, 0, NULL); |
| 389 |
if (fd == INVALID_HANDLE_VALUE) { |
| 390 |
free_if_alloc (file); |
| 391 |
return WPTERR_FILE_OPEN; |
| 392 |
} |
| 393 |
hpart = frees.HighPart; |
| 394 |
SetFilePointer (fd, frees.LowPart, &hpart, FILE_BEGIN); |
| 395 |
SetEndOfFile (fd); |
| 396 |
CloseHandle (fd); |
| 397 |
|
| 398 |
if (cb && cb_value) { |
| 399 |
progress_cb = cb; |
| 400 |
progress_cb_value = cb_value; |
| 401 |
} |
| 402 |
rc = _secure_unlink (file, WIPE_MODE_FAST, r_fd); |
| 403 |
|
| 404 |
handle_lowdiskspace_notify (drive, 0); |
| 405 |
free_if_alloc (file); |
| 406 |
return rc; |
| 407 |
} /* wipe_freespace */ |
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