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Message-ID: <20080331053554.GA4964@openwall.com>
Date: Mon, 31 Mar 2008 09:35:54 +0400
From: Solar Designer <solar@...nwall.com>
To: john-users@...ts.openwall.com
Subject: Re: passwords with fixed position characters and numbers
On Wed, Mar 26, 2008 at 10:11:43PM +0100, Ronald Brakeboer wrote:
> I only need some kind of script that generates all possible combinations
> from aaaa0000 - ZZZZ9999
Please find the brand new KnownForce external mode below, pre-configured
the way you have described above.
> And can someone tell me at what speed those could be generated in theory.
With this KnownForce mode and at these settings, I am getting over 1.5
million candidate passwords per second on a 1 GHz Pentium 3 running
Linux, with output to --stdout redirected to /dev/null. When cracking
fast hashes (e.g., LM) with JtR itself, the c/s rate is even higher.
# Generic implementation of exhaustive search for a partially-known password.
# This is pre-configured for length 8, lowercase and uppercase letters in the
# first 4 positions (52 different characters), and digits in the remaining 4
# positions - however, the corresponding part of init() may be modified to use
# arbitrary character sets or even fixed characters for each position.
[List.External:KnownForce]
int last; // Last character position, zero-based
int lastofs; // Last character position offset into charset[]
int lastid; // Current character index in the last position
int id[0x7f]; // Current character indices for other positions
int charset[0x7f00]; // Character sets, 0x100 elements for each position
void init()
{
int length;
int pos, ofs, i, c;
length = 8; // Password length to try
/* This defines the character sets for different character positions */
pos = 0;
while (pos < 4) {
ofs = pos++ << 8;
i = 0;
c = 'a';
while (c <= 'z')
charset[ofs + i++] = c++;
c = 'A';
while (c <= 'Z')
charset[ofs + i++] = c++;
charset[ofs + i] = 0;
}
while (pos < length) {
ofs = pos++ << 8;
i = 0;
c = '0';
while (c <= '9')
charset[ofs + i++] = c++;
charset[ofs + i] = 0;
}
last = length - 1;
pos = -1;
while (++pos <= last)
word[pos] = charset[id[pos] = pos << 8];
lastid = (lastofs = last << 8) - 1;
word[pos] = 0;
}
void generate()
{
int pos;
/* Handle the typical case specially */
if (word[last] = charset[++lastid]) return;
word[pos = last] = charset[lastid = lastofs];
while (pos--) { // Have a preceding position?
if (word[pos] = charset[++id[pos]]) return;
word[pos] = charset[id[pos] = pos << 8];
}
word = 0; // We're done
}
void restore()
{
int i, c;
/* Calculate the current length and infer the character indices */
last = 0;
while (c = word[last]) {
i = lastofs = last << 8;
while (charset[i] != c && charset[i]) i++;
if (!charset[i]) i = lastofs; // Not found
id[last++] = i;
}
lastid = id[--last];
}
--
Alexander Peslyak <solar at openwall.com>
GPG key ID: 5B341F15 fp: B3FB 63F4 D7A3 BCCC 6F6E FC55 A2FC 027C 5B34 1F15
http://www.openwall.com - bringing security into open computing environments
Was I helpful? Please give your feedback here: http://rate.affero.net/solar
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