sulogin: use common password-checking routine.

This needed some extensions correct_passwd() function,
which got renamed ask_and_check_password() to better describe what it does.

function                                             old     new   delta
ask_and_check_password_extended                        -     215    +215
ask_and_check_password                                 -      12     +12
vlock_main                                           394     397      +3
sulogin_main                                         494     326    -168
correct_password                                     207       -    -207
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 1/1 up/down: 230/-375)         Total: -145 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/libbb/correct_password.c b/libbb/correct_password.c
index 7cabd33d0..d02d0d6a0 100644
--- a/libbb/correct_password.c
+++ b/libbb/correct_password.c
@@ -31,12 +31,15 @@
 #include "libbb.h"
 
 /* Ask the user for a password.
+ * Return 1 without asking if PW has an empty password.
+ * Return -1 on EOF, error while reading input, or timeout.
  * Return 1 if the user gives the correct password for entry PW,
- * 0 if not.  Return 1 without asking if PW has an empty password.
+ * 0 if not.
  *
- * NULL pw means "just fake it for login with bad username" */
-
-int FAST_FUNC correct_password(const struct passwd *pw)
+ * NULL pw means "just fake it for login with bad username"
+ */
+int FAST_FUNC ask_and_check_password_extended(const struct passwd *pw,
+                int timeout, const char *prompt)
 {
         char *unencrypted, *encrypted;
         const char *correct;
@@ -65,9 +68,10 @@ int FAST_FUNC correct_password(const struct passwd *pw)
                 return 1;
 
  fake_it:
-        unencrypted = bb_ask_stdin("Password: ");
+        unencrypted = bb_ask(STDIN_FILENO, timeout, prompt);
         if (!unencrypted) {
-                return 0;
+                /* EOF (such as ^D) or error (such as ^C) */
+                return -1;
         }
         encrypted = pw_encrypt(unencrypted, correct, 1);
         r = (strcmp(encrypted, correct) == 0);
@@ -75,3 +79,8 @@ int FAST_FUNC correct_password(const struct passwd *pw)
         memset(unencrypted, 0, strlen(unencrypted));
         return r;
 }
+
+int FAST_FUNC ask_and_check_password(const struct passwd *pw)
+{
+        return ask_and_check_password_extended(pw, 0, "Password: ");
+}