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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-26 16:18:39 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-26 16:18:39 +0000
commit5242eef8fc54636a41701fd9d7083ba6e4a4e0b3 (patch)
treee6a0980092957865a937cc0f34446df3d5194e99 /lib/obscure.c
parentReleasing progress-linux version 1:4.13+dfsg1-5~progress7.99u1. (diff)
downloadshadow-5242eef8fc54636a41701fd9d7083ba6e4a4e0b3.tar.xz
shadow-5242eef8fc54636a41701fd9d7083ba6e4a4e0b3.zip
Merging upstream version 1:4.15.2.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/obscure.c')
-rw-r--r--lib/obscure.c224
1 files changed, 224 insertions, 0 deletions
diff --git a/lib/obscure.c b/lib/obscure.c
new file mode 100644
index 0000000..549c2a8
--- /dev/null
+++ b/lib/obscure.c
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+/*
+ * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 1999, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+
+#include <ctype.h>
+#include <stdio.h>
+
+#include "alloc.h"
+#include "attr.h"
+#include "memzero.h"
+#include "prototypes.h"
+#include "defines.h"
+#include "getdef.h"
+
+#if WITH_LIBBSD == 0
+#include "freezero.h"
+#endif /* WITH_LIBBSD */
+
+/*
+ * can't be a palindrome - like `R A D A R' or `M A D A M'
+ */
+static bool palindrome (MAYBE_UNUSED const char *old, const char *new)
+{
+ size_t i, j;
+
+ i = strlen (new);
+
+ for (j = 0; j < i; j++) {
+ if (new[i - j - 1] != new[j]) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/*
+ * more than half of the characters are different ones.
+ */
+
+static bool similar (/*@notnull@*/const char *old, /*@notnull@*/const char *new)
+{
+ int i, j;
+
+ /*
+ * XXX - sometimes this fails when changing from a simple password
+ * to a really long one (MD5). For now, I just return success if
+ * the new password is long enough. Please feel free to suggest
+ * something better... --marekm
+ */
+ if (strlen (new) >= 8) {
+ return false;
+ }
+
+ for (i = j = 0; ('\0' != new[i]) && ('\0' != old[i]); i++) {
+ if (strchr (new, old[i]) != NULL) {
+ j++;
+ }
+ }
+
+ if (i >= j * 2) {
+ return false;
+ }
+
+ return true;
+}
+
+static char *str_lower (/*@returned@*/char *string)
+{
+ char *cp;
+
+ for (cp = string; '\0' != *cp; cp++) {
+ *cp = tolower (*cp);
+ }
+ return string;
+}
+
+static /*@observer@*//*@null@*/const char *password_check (
+ /*@notnull@*/const char *old,
+ /*@notnull@*/const char *new,
+ /*@notnull@*/MAYBE_UNUSED const struct passwd *pwdp)
+{
+ const char *msg = NULL;
+ char *oldmono, *newmono, *wrapped;
+
+ if (strcmp (new, old) == 0) {
+ return _("no change");
+ }
+
+ newmono = str_lower (xstrdup (new));
+ oldmono = str_lower (xstrdup (old));
+ wrapped = XMALLOC(strlen(oldmono) * 2 + 1, char);
+ strcpy (wrapped, oldmono);
+ strcat (wrapped, oldmono);
+
+ if (palindrome (oldmono, newmono)) {
+ msg = _("a palindrome");
+ } else if (strcmp (oldmono, newmono) == 0) {
+ msg = _("case changes only");
+ } else if (similar (oldmono, newmono)) {
+ msg = _("too similar");
+ } else if (strstr (wrapped, newmono) != NULL) {
+ msg = _("rotated");
+ }
+ strzero (newmono);
+ strzero (oldmono);
+ strzero (wrapped);
+ free (newmono);
+ free (oldmono);
+ free (wrapped);
+
+ return msg;
+}
+
+static /*@observer@*//*@null@*/const char *obscure_msg (
+ /*@notnull@*/const char *old,
+ /*@notnull@*/const char *new,
+ /*@notnull@*/const struct passwd *pwdp)
+{
+ size_t maxlen, oldlen, newlen;
+ char *new1, *old1;
+ const char *msg;
+ const char *result;
+
+ oldlen = strlen (old);
+ newlen = strlen (new);
+
+ if (newlen < (size_t) getdef_num ("PASS_MIN_LEN", 0)) {
+ return _("too short");
+ }
+
+ /*
+ * Remaining checks are optional.
+ */
+ if (!getdef_bool ("OBSCURE_CHECKS_ENAB")) {
+ return NULL;
+ }
+
+ msg = password_check (old, new, pwdp);
+ if (NULL != msg) {
+ return msg;
+ }
+
+ result = getdef_str ("ENCRYPT_METHOD");
+ if (NULL == result) {
+ /* The traditional crypt() truncates passwords to 8 chars. It is
+ possible to circumvent the above checks by choosing an easy
+ 8-char password and adding some random characters to it...
+ Example: "password$%^&*123". So check it again, this time
+ truncated to the maximum length. Idea from npasswd. --marekm */
+
+ if (getdef_bool ("MD5_CRYPT_ENAB")) {
+ return NULL;
+ }
+
+ } else {
+
+ if ( (strcmp (result, "MD5") == 0)
+#ifdef USE_SHA_CRYPT
+ || (strcmp (result, "SHA256") == 0)
+ || (strcmp (result, "SHA512") == 0)
+#endif
+#ifdef USE_BCRYPT
+ || (strcmp (result, "BCRYPT") == 0)
+#endif
+#ifdef USE_YESCRYPT
+ || (strcmp (result, "YESCRYPT") == 0)
+#endif
+ ) {
+ return NULL;
+ }
+
+ }
+ maxlen = getdef_num ("PASS_MAX_LEN", 8);
+ if ( (oldlen <= maxlen)
+ && (newlen <= maxlen)) {
+ return NULL;
+ }
+
+ new1 = xstrdup (new);
+ old1 = xstrdup (old);
+ if (newlen > maxlen) {
+ new1[maxlen] = '\0';
+ }
+ if (oldlen > maxlen) {
+ old1[maxlen] = '\0';
+ }
+
+ msg = password_check (old1, new1, pwdp);
+
+ freezero (new1, newlen);
+ freezero (old1, oldlen);
+
+ return msg;
+}
+
+/*
+ * Obscure - see if password is obscure enough.
+ *
+ * The programmer is encouraged to add as much complexity to this
+ * routine as desired. Included are some of my favorite ways to
+ * check passwords.
+ */
+
+bool obscure (const char *old, const char *new, const struct passwd *pwdp)
+{
+ const char *msg = obscure_msg (old, new, pwdp);
+
+ if (NULL != msg) {
+ printf (_("Bad password: %s. "), msg);
+ return false;
+ }
+ return true;
+}