As we all know, standard DES crypt() uses only 8 characters of the
password passed to it. Alas, many people trip over this and expect
a long password to give them better protection. (We got security
reports for this already).
However, there are implementations which provide a concatenation of
several 8-byte-blocks. Do they still use the crypt() API? If not,
then I would propose to add one (or both) of the two attached patches:
<<htpasswd.c.diff>>:
Add an error exit to htpasswd which bails with ERR_OVERFLOW if the
password is too long for crypt() -- a similar exit is taken if the
password is too long for other reasons, e.g., because it was given on
the command line but exceeded 8kB in size.
<<htpasswd.xml.diff>>:
Document the restrictions implied by using DES crypt()
Comments?
Martin
--
<[EMAIL PROTECTED]> | Fujitsu Siemens
Fon: +49-89-636-46021, FAX: +49-89-636-47655 | 81730 Munich, Germany
Index: support/htpasswd.c
===================================================================
--- support/htpasswd.c (Revision 125380)
+++ support/htpasswd.c (Arbeitskopie)
@@ -175,6 +175,11 @@
#if !(defined(WIN32) || defined(NETWARE))
case ALG_CRYPT:
default:
+ if (strlen(pw) > 8) {
+ apr_snprintf(record, (rlen - 1), "password too long (must be <= %"
+ APR_SIZE_T_FMT " for crypt format) -- Hint: Use MD5
format", 8);
+ return ERR_OVERFLOW;
+ }
(void) srand((int) time((time_t *) NULL));
to64(&salt[0], rand(), 8);
salt[8] = '\0';
Index: docs/manual/programs/htpasswd.xml
===================================================================
--- docs/manual/programs/htpasswd.xml (Revision 125380)
+++ docs/manual/programs/htpasswd.xml (Arbeitskopie)
@@ -190,6 +190,15 @@
<p>The use of the <code>-b</code> option is discouraged, since when it is
used the unencrypted password appears on the command line.</p>
+
+ <p>When using the <code>crypt()</code> algorithm, note that only the first
+ 8 characters of the password are used to form the password. If the
supplied
+ password is longer, the extra characters will be silently discarded.</p>
+
+ <p>The SHA encryption format does not use salting: for a given password,
+ there is only one encrypted representation. The <code>crypt()</code> and
+ MD5 formats permute the representation by prepending a random salt string,
+ to make dictionary attacks against the passwords more difficult.</p>
</section>
<section id="restrictions"><title>Restrictions</title>
