[src/netbsd-1-6]: src/usr.sbin/user Pull up revision 1.61-1.62 (requested by ...

[tron <tron%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ee0ec99f800a
branches:  netbsd-1-6
changeset: 529819:ee0ec99f800a
user:      tron <tron%NetBSD.org@localhost>
date:      Thu Dec 26 07:28:50 2002 +0000

description:
Pull up revision 1.61-1.62 (requested by he in ticket #1041):
Handle PR 18474 in a more safe and scalable fashion - keep a table of
password types, and their associated lengths, and check in useradd or
usermod whether the given encrypted password has the correct length.
This removes the (duplicated) hardcoded lengths which had crept in
with the last commit, and also checks the length of the given password
against the expected length.

diffstat:

 usr.sbin/user/user.c |  60 +++++++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 50 insertions(+), 10 deletions(-)

diffs (95 lines):

diff -r 765bfaa87d60 -r ee0ec99f800a usr.sbin/user/user.c
--- a/usr.sbin/user/user.c      Sun Dec 22 13:40:56 2002 +0000
+++ b/usr.sbin/user/user.c      Thu Dec 26 07:28:50 2002 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: user.c,v 1.51.2.2 2002/12/06 23:40:26 he Exp $ */
+/* $NetBSD: user.c,v 1.51.2.3 2002/12/26 07:28:50 tron Exp $ */
 
 /*
  * Copyright (c) 1999 Alistair G. Crooks.  All rights reserved.
@@ -35,7 +35,7 @@
 #ifndef lint
 __COPYRIGHT("@(#) Copyright (c) 1999 \
                The NetBSD Foundation, Inc.  All rights reserved.");
-__RCSID("$NetBSD: user.c,v 1.51.2.2 2002/12/06 23:40:26 he Exp $");
+__RCSID("$NetBSD: user.c,v 1.51.2.3 2002/12/26 07:28:50 tron Exp $");
 #endif
 
 #include <sys/types.h>
@@ -868,6 +868,46 @@
        return 0;
 }
 
+/* structure which defines a password type */
+typedef struct passwd_type_t {
+       const char     *type;           /* optional type descriptor */
+       int             desc_length;    /* length of type descriptor */
+       int             length;         /* length of password */
+       const char     *regex;          /* regexp to output the password */
+       int             re_sub;         /* subscript of regexp to use */
+} passwd_type_t;
+
+static passwd_type_t   passwd_types[] = {
+       { "$2a",        3,      54,     "\\$[^$]+\\$[^$]+\\$(.*)",      1 },    /* Blowfish */
+       { "$1",         2,      34,     NULL,                           0 },    /* MD5 */
+       { "",           0,      13,     NULL,                           0 },    /* standard DES */
+       { NULL,         -1,     -1,     NULL,                           0 }     /* none - terminate search */
+};
+
+/* return non-zero if it's a valid password - check length for cipher type */
+static int
+valid_password_length(char *newpasswd)
+{
+       passwd_type_t  *pwtp;
+       regmatch_t      matchv[10];
+       regex_t         r;
+
+       for (pwtp = passwd_types ; pwtp->desc_length >= 0 ; pwtp++) {
+               if (strncmp(newpasswd, pwtp->type, pwtp->desc_length) == 0) {
+                       if (pwtp->regex == NULL) {
+                               return strlen(newpasswd) == pwtp->length;
+                       }
+                       (void) regcomp(&r, pwtp->regex, REG_EXTENDED);
+                       if (regexec(&r, newpasswd, 10, matchv, 0) == 0) {
+                               regfree(&r);
+                               return (int)(matchv[pwtp->re_sub].rm_eo - matchv[pwtp->re_sub].rm_so + 1) == pwtp->length;
+                       }
+                       regfree(&r);
+               }
+       }
+       return 0;
+}
+
 /* add a user */
 static int
 adduser(char *login, user_t *up)
@@ -1006,10 +1046,7 @@
                    home);
        }
        password[sizeof(password) - 1] = '\0';
-       if (up->u_password != NULL &&
-           (strlen(up->u_password) == 13 ||
-            strncmp(up->u_password, "$1", 2) == 0 ||
-            strncmp(up->u_password, "$2", 2) == 0)) {
+       if (up->u_password != NULL && valid_password_length(up->u_password)) {
                (void) strlcpy(password, up->u_password, sizeof(password));
        } else {
                (void) memset(password, '\0', sizeof(password));
@@ -1141,10 +1178,13 @@
                        }
                }
                if (up->u_flags & F_PASSWORD) {
-                       if (up->u_password != NULL &&
-                           (strlen(up->u_password) == 13 ||
-                            strncmp(up->u_password, "$1", 2) == 0 ||
-                            strncmp(up->u_password, "$2", 2) == 0)) {
+                       if (up->u_password != NULL) {
+                               if (!valid_password_length(up->u_password) > 0) {
+                                       (void) close(ptmpfd);
+                                       pw_abort();
+                                       errx(EXIT_FAILURE, "Invalid password: `%s'",
+                                               up->u_password);
+                               }
                                pwp->pw_passwd = up->u_password;
                        }
                }