view src/strcat.c @ 5891:a0e751d6c3ad

Import the #'clear-string API from GNU, use it in tls.c src/ChangeLog addition: 2015-04-18 Aidan Kehoe <kehoea@parhasard.net> * sequence.c (Fclear_string): New, API from GNU. Zero a string's contents, making sure the text is not kept around even when the string's data is reallocated because of a changed character length. * sequence.c (syms_of_sequence): Make it available to Lisp. * lisp.h: Make it available to C code. * tls.c (nss_pk11_password): Use it. * tls.c (gnutls_pk11_password): Use it. * tls.c (openssl_password): Use it. tests/ChangeLog addition: 2015-04-18 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-tests.el: Test #'clear-string, just added. Unfortunately there's no way to be certain from Lisp that the old password data has been erased after realloc; it may be worth adding a test to tests.c, but *we'll be reading memory we shouldn't be*, so that gives me pause.
author Aidan Kehoe <kehoea@parhasard.net>
date Sat, 18 Apr 2015 23:00:14 +0100
parents 2aa9cd456ae7
children
line wrap: on
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/* Copyright (C) 1991 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library 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, either version 3 of the License, or (at your
option) any later version.

The GNU C Library 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 the GNU C Library.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: Not in FSF. */

# include <config.h>
# ifndef REGISTER	/* Strictly enforced in 20.3 */
# define REGISTER
# endif

/* In HPUX 10 the strcat function references memory past the last byte of 
   the string!  This will core dump if the memory following the last byte is 
   not mapped.

   Here is a correct version from, glibc 1.09.
*/

char *strcat (char *dest, const char *src);

/* Append SRC on the end of DEST.  */
char *
strcat (char *dest, const char *src)
{
  REGISTER char *s1 = dest;
  REGISTER const char *s2 = src;
  char c;

  /* Find the end of the string.  */
  do
    c = *s1++;
  while (c != '\0');

  /* Make S1 point before the next character, so we can increment
     it while memory is read (wins on pipelined cpus).  */
  s1 -= 2;

  do
    {
      c = *s2++;
      *++s1 = c;
    }
  while (c != '\0');

  return dest;
}