security/nss/cmd/shlibsign/mangle/mangle.c

   1 /* ***** BEGIN LICENSE BLOCK *****
   2  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   3  *
   4  * The contents of this file are subject to the Mozilla Public License Version
   5  * 1.1 (the "License"); you may not use this file except in compliance with
   6  * the License. You may obtain a copy of the License at
   7  * http://www.mozilla.org/MPL/
   8  *
   9  * Software distributed under the License is distributed on an "AS IS" basis,
  10  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  11  * for the specific language governing rights and limitations under the
  12  * License.
  13  *
  14  * The Original Code is the Netscape security libraries.
  15  *
  16  * The Initial Developer of the Original Code is
  17  * Netscape Communications Corporation.
  18  * Portions created by the Initial Developer are Copyright (C) 1994-2003
  19  * the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *
  23  * Alternatively, the contents of this file may be used under the terms of
  24  * either the GNU General Public License Version 2 or later (the "GPL"), or
  25  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  26  * in which case the provisions of the GPL or the LGPL are applicable instead
  27  * of those above. If you wish to allow use of your version of this file only
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  32  * the provisions above, a recipient may use your version of this file under
  33  * the terms of any one of the MPL, the GPL or the LGPL.
  34  *
  35  * ***** END LICENSE BLOCK ***** */
  36
  37 /*
  38  * Test program to mangle 1 bit in a binary
  39  *
  40  * $Id: mangle.c,v 1.7 2007/01/26 19:38:05 nelson%bolyard.com Exp $
  41  */
  42
  43 #include "nspr.h"
  44 #include "plstr.h"
  45 #include "plgetopt.h"
  46 #include "prio.h"
  47
  48 static PRFileDesc *pr_stderr;
  49 static void
  50 usage (char *program_name)
  51 {
  52
  53     PR_fprintf (pr_stderr, "Usage:");
  54     PR_fprintf (pr_stderr, "%s -i shared_library_name -o byte_offset -b bit\n", program_name);
  55 }
  56
  57
  58 int
  59 main (int argc, char **argv)
  60 {
  61     /* buffers and locals */
  62     PLOptState  *optstate;
  63     char        *programName;
  64     char        cbuf;
  65
  66     /* parameter set variables */
  67     const char  *libFile = NULL;
  68     int bitOffset = -1;
  69
  70     /* return values */
  71     int          retval = 2;  /* 0 - test succeeded.
  72                                * 1 - illegal args
  73                                * 2 - function failed */
  74     PRFileDesc *fd = NULL;
  75     int bytesRead;
  76     int bytesWritten;
  77     PROffset32   offset = -1;
  78     PROffset32   pos;
  79
  80     programName = PL_strrchr(argv[0], '/');
  81     programName = programName ? (programName + 1) : argv[0];
  82
  83     pr_stderr = PR_STDERR;
  84
  85     optstate = PL_CreateOptState (argc, argv, "i:o:b:");
  86     if (optstate == NULL) {
  87         return 1;
  88     }
  89
  90     while (PL_GetNextOpt (optstate) == PL_OPT_OK) {
  91         switch (optstate->option) {
  92           case 'i':
  93             libFile = optstate->value;
  94             break;
  95
  96           case 'o':
  97             offset = atoi(optstate->value);
  98             break;
  99
 100           case 'b':
 101             bitOffset = atoi(optstate->value);
 102             break;
 103         }
 104     }
 105
 106     if (libFile == NULL) {
 107         usage(programName);
 108         return 1;
 109     }
 110     if ((bitOffset >= 8) || (bitOffset < 0)) {
 111         usage(programName);
 112         return 1;
 113     }
 114
 115     /* open the target signature file */
 116     fd = PR_OpenFile(libFile,PR_RDWR,0666);
 117     if (fd == NULL ) {
 118         /* lperror(libFile); */
 119         PR_fprintf(pr_stderr,"Couldn't Open %s\n",libFile);
 120         goto loser;
 121     }
 122
 123     if (offset < 0) { /* convert to positive offset */
 124         pos = PR_Seek(fd, offset, PR_SEEK_END);
 125         if (pos == -1) {
 126             PR_fprintf(pr_stderr,"Seek for read on %s (to %d) failed\n",
 127                        libFile, offset);
 128             goto loser;
 129         }
 130         offset = pos;
 131     }
 132
 133     /* read the byte */
 134     pos = PR_Seek(fd, offset, PR_SEEK_SET);
 135     if (pos != offset) {
 136         PR_fprintf(pr_stderr,"Seek for read on %s (to %d) failed\n",
 137                    libFile, offset);
 138         goto loser;
 139     }
 140     bytesRead = PR_Read(fd, &cbuf, 1);
 141     if (bytesRead != 1) {
 142         PR_fprintf(pr_stderr,"Read on %s (to %d) failed\n", libFile, offset);
 143         goto loser;
 144     }
 145
 146     PR_fprintf(pr_stderr,"Changing byte 0x%08x (%d): from %02x (%d) to ",
 147                 offset, offset, (unsigned char)cbuf, (unsigned char)cbuf);
 148     /* change it */
 149     cbuf ^= 1 << bitOffset;
 150     PR_fprintf(pr_stderr,"%02x (%d)\n",
 151                (unsigned char)cbuf, (unsigned char)cbuf);
 152
 153     /* write it back out */
 154     pos = PR_Seek(fd, offset, PR_SEEK_SET);
 155     if (pos != offset) {
 156         PR_fprintf(pr_stderr,"Seek for write on %s (to %d) failed\n",
 157                    libFile, offset);
 158         goto loser;
 159     }
 160     bytesWritten = PR_Write(fd, &cbuf, 1);
 161     if (bytesWritten != 1) {
 162         PR_fprintf(pr_stderr,"Write on %s (to %d) failed\n", libFile, offset);
 163         goto loser;
 164     }
 165
 166     retval = 0;
 167
 168 loser:
 169     if (fd)
 170         PR_Close(fd);
 171     PR_Cleanup ();
 172     return retval;
 173 }
 174
 175 /*#DEFINES += -DSHLIB_SUFFIX=\"$(DLL_SUFFIX)\" -DSHLIB_PREFIX=\"$(DLL_PREFIX)\" */