apps/src/init.c

@@ -53,6 +53,8 @@ int main()
 
     show_motd();
 
+    msleep(200);
+
     pid_t child = fork();
     if (child < 0)
     {

apps/src/session.c

@@ -39,24 +39,6 @@ static void strip_newline(char* str)
     if (str[len - 1] == '\n') str[len - 1] = 0;
 }
 
-static char* collect_password()
-{
-    static char buf[BUFSIZ];
-
-    printf("Password: ");
-    fgets(buf, BUFSIZ, stdin);
-
-    strip_newline(buf);
-    putchar('\n');
-
-    char* copy = strdup(
-        buf); // The password only stays in a caller-controlled heap-allocated buffer, where it can be freed at will.
-
-    memset(buf, 0, BUFSIZ);
-
-    return copy;
-}
-
 static void login_as(struct passwd* user)
 {
     pid_t child = fork();
@@ -92,19 +74,18 @@ static int login()
             printf("Unknown user %s\n", username);
         return 0;
     }
-    char* password = collect_password();
-    putchar('\n');
+    printf("Password: ");
+    char password[BUFSIZ];
+    fgets(password, BUFSIZ, stdin);
+    strip_newline(password);
+    puts("\n");
     if (strcmp(user->pw_passwd, password) == 0)
     {
-        free(password);
         login_as(user);
         puts("logout\n");
     }
     else
-    {
-        free(password);
         puts("Invalid password.\n");
-    }
     return 0;
 }
 

apps/src/sh.c

@@ -87,7 +87,6 @@ void show_prompt()
             username = "??";
         }
         else { username = user->pw_name; }
-        atexit(endpwent);
     }
     if (WEXITSTATUS(status)) { printf("%d [%s]> ", WEXITSTATUS(status), username); }
     else

apps/src/su.c

@@ -19,26 +19,13 @@ void strip_newline(char* str)
     if (str[len - 1] == '\n') str[len - 1] = 0;
 }
 
-static const char* collect_password()
-{
-    static char buf[BUFSIZ];
-
-    printf("Password: ");
-    fgets(buf, BUFSIZ, stdin);
-
-    strip_newline(buf);
-    putchar('\n');
-
-    return buf;
-}
-
 int main(int argc, char** argv)
 {
-    const char* username;
-
-    if (argc == 1) username = "root";
-    else
-        username = argv[1];
+    if (argc == 1)
+    {
+        fprintf(stderr, "Usage: %s [username] [command | login shell]\n", argv[0]);
+        return EXIT_FAILURE;
+    }
 
     if (getuid() != 0)
     {
@@ -46,22 +33,24 @@ int main(int argc, char** argv)
         return EXIT_FAILURE;
     }
 
-    struct passwd* user = getpwnam(username);
-
-    endpwent();
+    struct passwd* user = getpwnam(argv[1]);
 
     if (!user)
     {
         if (errno) perror("getpwnam");
         else
-            fprintf(stderr, "Unknown user %s\n", username);
+            fprintf(stderr, "Unknown user %s\n", argv[1]);
         return EXIT_FAILURE;
     }
 
     if (getuid() != geteuid()) // we were started from a non-root user
     {
-        const char* pw = collect_password();
-        if (strcmp(pw, user->pw_passwd) != 0)
+        printf("Password: ");
+        char buf[BUFSIZ];
+        fgets(buf, BUFSIZ, stdin);
+        strip_newline(buf);
+        putchar('\n');
+        if (strcmp(buf, user->pw_passwd) != 0)
         {
             fprintf(stderr, "Invalid password\n");
             return EXIT_FAILURE;