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Message-ID: <20150510234027.GA28403@openwall.com>
Date: Mon, 11 May 2015 02:40:27 +0300
From: Aleksey Cherepanov <lyosha@...nwall.com>
To: john-dev@...ts.openwall.com
Subject: Re: displaying full meta information about hashes with
--show=types
On Sun, May 10, 2015 at 11:32:52PM +0300, Alexander Cherepanov wrote:
> On 2015-05-10 21:43, Aleksey Cherepanov wrote:
> >I implemented --show=types option that prints all meta information
> >about hashes from file. It tries all formats against all hashes and
> >prints result in machine parseable format. It applies even formats
> >that are disabled. It tries generic crypt always. It respects
> >--format= option. It does not bypass john's heuristics for generic
> >crypt.
>
> Cool, it will be useful in scripts for sorting and converting hashes.
It should be useful for Johnny too.
While I intended to make code that prints something for each line of
input file, the code skips bare lines of length < 13 when they consist
of letters.
Fro instance: abcdefghijkl
These are loaded:
1234567890
abcdefghijklm - loaded and validated as crypt: abcdefghijklm
abcdefghijklmo
Loading of the line with : at the beginning works:
:abcdefghijk
:abcdefghijkl
The code responsible for the skipping:
fields[0] = *login = ldr_get_field(&line, db_opts->field_sep_char);
fields[1] = *ciphertext = ldr_get_field(&line, db_opts->field_sep_char);
/* Check for NIS stuff */
if ((!strcmp(*login, "+") || !strncmp(*login, "+@", 2)) &&
strlen(*ciphertext) < 10 && strncmp(*ciphertext, "$dummy$", 7)
&& strncmp(*ciphertext, "$0$", 3))
return 0;
if (!**ciphertext && !line) {
/* Possible hash on a line on its own (no colons) */
char *p = *login;
/* Skip leading and trailing whitespace */
while (*p == ' ' || *p == '\t') p++;
*ciphertext = p;
p += strlen(p) - 1;
while (p > *ciphertext && (*p == ' ' || *p == '\t')) p--;
p++;
/* Some valid dummy or plaintext hashes may be shorter than 10 characters,
* so don't subject them to the length checks. */
if (strncmp(*ciphertext, "$dummy$", 7) &&
strncmp(*ciphertext, "$0$", 3) &&
p - *ciphertext != 10 /* not tripcode */) {
/* Check for a special case: possibly a traditional crypt(3) hash with
* whitespace in its invalid salt. Only support such hashes at the very start
* of a line (no leading whitespace other than the invalid salt). */
if (p - *ciphertext == 11 && *ciphertext - *login == 2)
(*ciphertext)--;
if (p - *ciphertext == 12 && *ciphertext - *login == 1)
(*ciphertext)--;
if (p - *ciphertext < 13)
return 0;
}
*p = 0;
fields[0] = *login = no_username;
fields[1] = *ciphertext;
}
I am not sure what to do. You see 2 return statements here. There are
3 more before my code, they do not need to be handled specially.
if (ldr_check_list(db_opts->users, *login, *uid)) return 0;
if (ldr_check_list(db_opts->groups, gid, gid)) return 0;
if (ldr_check_shells(db_opts->shells, shell)) return 0;
While the first 2 'return' statements may be extended to print the
line to be skipped in --show=types mode before exit.
Thanks!
--
Regards,
Aleksey Cherepanov
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