cryptpw: do not segfault on EOF. Closes 6350

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

1 files changed, 12 insertions, 7 deletions

diff --git a/loginutils/cryptpw.c b/loginutils/cryptpw.c
index a36f920f4..29f0fbe91 100644
--- a/loginutils/cryptpw.c
+++ b/loginutils/cryptpw.c
@@ -92,6 +92,7 @@ int cryptpw_main(int argc UNUSED_PARAM, char **argv)
 {
         char salt[MAX_PW_SALT_LEN];
         char *salt_ptr;
+        char *password;
         const char *opt_m, *opt_S;
         int fd;
 
@@ -123,15 +124,19 @@ int cryptpw_main(int argc UNUSED_PARAM, char **argv)
 
         xmove_fd(fd, STDIN_FILENO);
 
-        puts(pw_encrypt(
-                argv[0] ? argv[0] : (
-                        /* Only mkpasswd, and only from tty, prompts.
-                         * Otherwise it is a plain read. */
-                        (isatty(STDIN_FILENO) && applet_name[0] == 'm')
+        password = argv[0];
+        if (!password) {
+                /* Only mkpasswd, and only from tty, prompts.
+                 * Otherwise it is a plain read. */
+                password = (isatty(STDIN_FILENO) && applet_name[0] == 'm')
                         ? bb_ask_stdin("Password: ")
                         : xmalloc_fgetline(stdin)
-                ),
-                salt, 1));
+                ;
+                /* may still be NULL on EOF/error */
+        }
+
+        if (password)
+                puts(pw_encrypt(password, salt, 1));
 
         return EXIT_SUCCESS;
 }