What hash to use

[Derek (freebsd lists)]

On 2018-08-23 05:16 AM, Olivier wrote:
> I am using a tools that hashes the passwords in the form of
> $2b$10$OQBll77HJqnOR.zqK2jx8ukE6m68Azc7nrsgRdcT6bVfERRmzFV4.
> 
> What magic tool can I use in freeBSD to do the same hashing?
> 

Try this (cdemo.c):

#include <stdio.h>
#include <string.h>
#include <unistd.h>

int main(void)
{
         struct crypt_data buf1;
         char *hash;

         /*
          * Generate a crypt for storage, using salt as the 
algorithm selection
          * and parameters.
          */
         hash = crypt_r("Initial example password.", 
"$2b$10$22bytesofbase64charactersfromdevurandom", &buf1);
         if (hash == NULL) {
                 printf("crypt_r (hash) failed.\n");
                 return (3);
         }

         printf("crypt_r (hash) result: %s\n", hash);

         return (0);
}


Then:

cc -lcrypt -o cdemo cdemo.c
./cdemo

This is okay for a one-off.

You might wire stdin to read the salt, or for bonus points make 
your own salt generator.

Additionally, it's likely not a good idea to read the password 
from the command-line (argv+argc).  A file descriptor (e.g. 
stdin) of some kind would be better, as it will show up in shell 
history and the process table.

Some languages, e.g. python, php, etc will have a library to do 
this for you as well.

Derek