chsh-chfn: Move pam auth to its own function, factoring out common code

This makes it easier to add support for libuser, which needs the same PAM
authentication. Also removes duplicate code between chsh and chfn.

Signed-off-by: Cody Maloney <cmaloney@theoreticalchaos.com>

5 files changed, 68 insertions, 60 deletions

diff --git a/login-utils/Makemodule.am b/login-utils/Makemodule.am
index 479b87b0f..ee853295c 100644
--- a/login-utils/Makemodule.am
+++ b/login-utils/Makemodule.am
@@ -62,6 +62,8 @@ dist_man_MANS += \
 chfn_chsh_sources = \
 	login-utils/islocal.c \
 	login-utils/islocal.h \
+	login-utils/auth.c \
+	login-utils/auth.h \
 	login-utils/setpwnam.c \
 	login-utils/setpwnam.h
 chfn_chsh_cflags = $(SUID_CFLAGS) $(AM_CFLAGS)
diff --git a/login-utils/auth.c b/login-utils/auth.c
new file mode 100644
index 000000000..373bd22c1
--- /dev/null
+++ b/login-utils/auth.c
@@ -0,0 +1,47 @@
+/*
+ *   auth.c -- PAM authorization code, common between chsh and chfn
+ *   (c) 2012 by Cody Maloney <cmaloney@theoreticalchaos.com>
+ *
+ *   this program is free software.  you can redistribute it and
+ *   modify it under the terms of the gnu general public license.
+ *   there is no warranty.
+ *
+ */
+
+#include "auth.h"
+
+#include "pamfail.h"
+
+int auth_pam(const char *service_name, uid_t uid, const char *username) {
+#ifdef REQUIRE_PASSWORD
+	if (uid != 0) {
+		pam_handle_t *pamh = NULL;
+		struct pam_conv conv = { misc_conv, NULL };
+		int retcode;
+
+		retcode = pam_start(service_name, username, &conv, &pamh);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		retcode = pam_authenticate(pamh, 0);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		retcode = pam_acct_mgmt(pamh, 0);
+		if (retcode == PAM_NEW_AUTHTOK_REQD)
+			retcode =
+			    pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		retcode = pam_setcred(pamh, 0);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		pam_end(pamh, 0);
+		/* no need to establish a session; this isn't a
+		 * session-oriented activity...  */
+	}
+	return TRUE;
+#endif	/* REQUIRE_PASSWORD */
+}
diff --git a/login-utils/auth.h b/login-utils/auth.h
new file mode 100644
index 000000000..bf7c36924
--- /dev/null
+++ b/login-utils/auth.h
@@ -0,0 +1,13 @@
+/*
+ *   auth.h -- PAM authorization code, common between chsh and chfn
+ *   (c) 2012 by Cody Maloney <cmaloney@theoreticalchaos.com>
+ *
+ *   this program is free software.  you can redistribute it and
+ *   modify it under the terms of the gnu general public license.
+ *   there is no warranty.
+ *
+ */
+
+#include <sys/types.h>
+
+extern int auth_pam(const char *service_name, uid_t uid, const char *username);
diff --git a/login-utils/chfn.c b/login-utils/chfn.c
index b240ec725..7c9af8403 100644
--- a/login-utils/chfn.c
+++ b/login-utils/chfn.c
@@ -31,12 +31,12 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include "auth.h"
 #include "c.h"
 #include "env.h"
 #include "closestream.h"
 #include "islocal.h"
 #include "nls.h"
-#include "pamfail.h"
 #include "setpwnam.h"
 #include "strutils.h"
 #include "xalloc.h"
@@ -157,36 +157,9 @@ int main(int argc, char **argv)
 
 	printf(_("Changing finger information for %s.\n"), oldf.username);
 
-#ifdef REQUIRE_PASSWORD
-	if (uid != 0) {
-		pam_handle_t *pamh = NULL;
-		struct pam_conv conv = { misc_conv, NULL };
-		int retcode;
-
-		retcode = pam_start("chfn", oldf.username, &conv, &pamh);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		retcode = pam_authenticate(pamh, 0);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		retcode = pam_acct_mgmt(pamh, 0);
-		if (retcode == PAM_NEW_AUTHTOK_REQD)
-			retcode =
-			    pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		retcode = pam_setcred(pamh, 0);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		pam_end(pamh, 0);
-		/* no need to establish a session; this isn't a
-		 * session-oriented activity...  */
+	if(!auth_pam("chfn", uid, oldf.username)) {
+		return EXIT_FAILURE;
 	}
-#endif	/* REQUIRE_PASSWORD */
 
 	if (interactive)
 		ask_info(&oldf, &newf);
diff --git a/login-utils/chsh.c b/login-utils/chsh.c
index f83b0571d..7d3963fc0 100644
--- a/login-utils/chsh.c
+++ b/login-utils/chsh.c
@@ -32,12 +32,12 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include "auth.h"
 #include "c.h"
 #include "env.h"
 #include "closestream.h"
 #include "islocal.h"
 #include "nls.h"
-#include "pamfail.h"
 #include "pathnames.h"
 #include "setpwnam.h"
 #include "xalloc.h"
@@ -147,36 +147,9 @@ int main(int argc, char **argv)
 
 	printf(_("Changing shell for %s.\n"), pw->pw_name);
 
-#ifdef REQUIRE_PASSWORD
-	if (uid != 0) {
-		pam_handle_t *pamh = NULL;
-		struct pam_conv conv = { misc_conv, NULL };
-		int retcode;
-
-		retcode = pam_start("chsh", pw->pw_name, &conv, &pamh);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		retcode = pam_authenticate(pamh, 0);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		retcode = pam_acct_mgmt(pamh, 0);
-		if (retcode == PAM_NEW_AUTHTOK_REQD)
-			retcode =
-			    pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		retcode = pam_setcred(pamh, 0);
-		if (pam_fail_check(pamh, retcode))
-			return EXIT_FAILURE;
-
-		pam_end(pamh, 0);
-		/* no need to establish a session; this isn't a
-		 * session-oriented activity...  */
+	if(!auth_pam("chsh", uid, pw->pw_name)) {
+		return EXIT_FAILURE;
 	}
-#endif	/* REQUIRE_PASSWORD */
 
 	if (!shell) {
 		shell = prompt(_("New shell"), oldshell);