From 2923d026e55998133c0f6e5186dca2a3c0fa5ff5 Mon Sep 17 00:00:00 2001
From: Darren Tucker <dtucker@dtucker.net>
Date: Sat, 26 Mar 2022 12:49:50 +1100
Subject: [PATCH] Factor out platform-specific locked account check.

Also fixes an incorrect free on platforms with both libiaf and shadow
passwords (probably only Unixware).  Prompted by github PR#284,
originally from @c3h2_ctf and stoeckmann@.
---
 auth.c     | 50 +++-----------------------------------------------
 platform.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 platform.h |  1 +
 3 files changed, 55 insertions(+), 47 deletions(-)

diff --git a/auth.c b/auth.c
index 560e8ecac..81d275895 100644
--- a/auth.c
+++ b/auth.c
@@ -104,59 +104,15 @@ allowed_user(struct ssh *ssh, struct passwd * pw)
 	const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
 	u_int i;
 	int r;
-#ifdef USE_SHADOW
-	struct spwd *spw = NULL;
-#endif
 
 	/* Shouldn't be called if pw is NULL, but better safe than sorry... */
 	if (!pw || !pw->pw_name)
 		return 0;
 
-#ifdef USE_SHADOW
-	if (!options.use_pam)
-		spw = getspnam(pw->pw_name);
-#ifdef HAS_SHADOW_EXPIRE
-	if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw))
+	if (!options.use_pam && platform_locked_account(pw)) {
+		logit("User %.100s not allowed because account is locked",
+		    pw->pw_name);
 		return 0;
-#endif /* HAS_SHADOW_EXPIRE */
-#endif /* USE_SHADOW */
-
-	/* grab passwd field for locked account check */
-	passwd = pw->pw_passwd;
-#ifdef USE_SHADOW
-	if (spw != NULL)
-#ifdef USE_LIBIAF
-		passwd = get_iaf_password(pw);
-#else
-		passwd = spw->sp_pwdp;
-#endif /* USE_LIBIAF */
-#endif
-
-	/* check for locked account */
-	if (!options.use_pam && passwd && *passwd) {
-		int locked = 0;
-
-#ifdef LOCKED_PASSWD_STRING
-		if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0)
-			 locked = 1;
-#endif
-#ifdef LOCKED_PASSWD_PREFIX
-		if (strncmp(passwd, LOCKED_PASSWD_PREFIX,
-		    strlen(LOCKED_PASSWD_PREFIX)) == 0)
-			 locked = 1;
-#endif
-#ifdef LOCKED_PASSWD_SUBSTR
-		if (strstr(passwd, LOCKED_PASSWD_SUBSTR))
-			locked = 1;
-#endif
-#ifdef USE_LIBIAF
-		free((void *) passwd);
-#endif /* USE_LIBIAF */
-		if (locked) {
-			logit("User %.100s not allowed because account is locked",
-			    pw->pw_name);
-			return 0;
-		}
 	}
 
 	/*
diff --git a/platform.c b/platform.c
index 44ba71dc5..4fe8744ee 100644
--- a/platform.c
+++ b/platform.c
@@ -18,6 +18,7 @@
 
 #include <stdarg.h>
 #include <stdio.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "log.h"
@@ -197,3 +198,53 @@ platform_krb5_get_principal_name(const char *pw_name)
 	return NULL;
 #endif
 }
+
+/* returns 1 if account is locked */
+int
+platform_locked_account(struct passwd *pw)
+{
+	int locked = 0;
+	char *passwd = pw->pw_passwd;
+#ifdef USE_SHADOW
+	struct spwd *spw = NULL;
+#ifdef USE_LIBIAF
+	char *iaf_passwd = NULL;
+#endif
+
+	spw = getspnam(pw->pw_name);
+#ifdef HAS_SHADOW_EXPIRE
+	if (spw != NULL && auth_shadow_acctexpired(spw))
+		return 1;
+#endif /* HAS_SHADOW_EXPIRE */
+
+	if (spw != NULL)
+#ifdef USE_LIBIAF
+		iaf_passwd = passwd = get_iaf_password(pw);
+#else
+		passwd = spw->sp_pwdp;
+#endif /* USE_LIBIAF */
+#endif
+
+	/* check for locked account */
+	if (passwd && *passwd) {
+#ifdef LOCKED_PASSWD_STRING
+		if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0)
+			locked = 1;
+#endif
+#ifdef LOCKED_PASSWD_PREFIX
+		if (strncmp(passwd, LOCKED_PASSWD_PREFIX,
+		    strlen(LOCKED_PASSWD_PREFIX)) == 0)
+			locked = 1;
+#endif
+#ifdef LOCKED_PASSWD_SUBSTR
+		if (strstr(passwd, LOCKED_PASSWD_SUBSTR))
+			locked = 1;
+#endif
+	}
+#ifdef USE_LIBIAF
+	if (iaf_passwd != NULL)
+		freezero(iaf_passwd, strlen(iaf_passwd));
+#endif /* USE_LIBIAF */
+
+	return locked;
+}
diff --git a/platform.h b/platform.h
index ea4f9c584..98c48da40 100644
--- a/platform.h
+++ b/platform.h
@@ -28,6 +28,7 @@ void platform_setusercontext(struct passwd *);
 void platform_setusercontext_post_groups(struct passwd *);
 char *platform_get_krb5_client(const char *);
 char *platform_krb5_get_principal_name(const char *);
+int platform_locked_account(struct passwd *)
 int platform_sys_dir_uid(uid_t);
 void platform_disable_tracing(int);