glibc/manual/examples/genpass.c
Paul Eggert 2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00

60 lines
1.6 KiB
C

/* Encrypting Passwords
Copyright (C) 1991-2021 Free Software Foundation, Inc.
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; either version 2
of the License, or (at your option) any later version.
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, see <https://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <unistd.h>
#include <crypt.h>
int
main(void)
{
unsigned char ubytes[16];
char salt[20];
const char *const saltchars =
"./0123456789ABCDEFGHIJKLMNOPQRST"
"UVWXYZabcdefghijklmnopqrstuvwxyz";
char *hash;
int i;
/* Retrieve 16 unpredictable bytes from the operating system. */
if (getentropy (ubytes, sizeof ubytes))
{
perror ("getentropy");
return 1;
}
/* Use them to fill in the salt string. */
salt[0] = '$';
salt[1] = '5'; /* SHA-256 */
salt[2] = '$';
for (i = 0; i < 16; i++)
salt[3+i] = saltchars[ubytes[i] & 0x3f];
salt[3+i] = '\0';
/* Read in the user's passphrase and hash it. */
hash = crypt (getpass ("Enter new passphrase: "), salt);
if (!hash || hash[0] == '*')
{
perror ("crypt");
return 1;
}
/* Print the results. */
puts (hash);
return 0;
}