tar: support -T - and -X -

[oweals/busybox.git] / libbb / correct_password.c

diff --git a/libbb/correct_password.c b/libbb/correct_password.c
index c515b26afb581402f6e974861a7820997895d12d..6301589e6ae2ba227d138fb3fff27ea025c5c5b9 100644 (file)
--- a/libbb/correct_password.c
+++ b/libbb/correct_password.c
@@ -31,39 +31,50 @@
 #include "libbb.h"
 
 /* Ask the user for a password.
-   Return 1 if the user gives the correct password for entry PW,
-   0 if not.  Return 1 without asking for a password if run by UID 0
-   or if PW has an empty password.  */
+ * 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.
+ *
+ * NULL pw means "just fake it for login with bad username" */
 
-int correct_password(const struct passwd *pw)
+int FAST_FUNC correct_password(const struct passwd *pw)
 {
        char *unencrypted, *encrypted;
        const char *correct;
+       int r;
 #if ENABLE_FEATURE_SHADOWPASSWDS
        /* Using _r function to avoid pulling in static buffers */
        struct spwd spw;
-       struct spwd *result;
        char buffer[256];
 #endif
 
+       /* fake salt. crypt() can choke otherwise. */
+       correct = "aa";
+       if (!pw) {
+               /* "aa" will never match */
+               goto fake_it;
+       }
        correct = pw->pw_passwd;
 #if ENABLE_FEATURE_SHADOWPASSWDS
-       if (LONE_CHAR(pw->pw_passwd, 'x') || LONE_CHAR(pw->pw_passwd, '*')) {
-               if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result))
-                       bb_error_msg("no valid shadow password, checking ordinary one");
-               else
-                       correct = spw.sp_pwdp;
+       if ((correct[0] == 'x' || correct[0] == '*') && !correct[1]) {
+               /* getspnam_r may return 0 yet set result to NULL.
+                * At least glibc 2.4 does this. Be extra paranoid here. */
+               struct spwd *result = NULL;
+               r = getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result);
+               correct = (r || !result) ? "aa" : result->sp_pwdp;
        }
 #endif
 
-       if (!correct || correct[0] == '\0')
+       if (!correct[0]) /* empty password field? */
                return 1;
 
-       unencrypted = bb_askpass(0, "Password: ");
+ fake_it:
+       unencrypted = bb_ask_stdin("Password: ");
        if (!unencrypted) {
                return 0;
        }
-       encrypted = crypt(unencrypted, correct);
+       encrypted = pw_encrypt(unencrypted, correct, 1);
+       r = (strcmp(encrypted, correct) == 0);
+       free(encrypted);
        memset(unencrypted, 0, strlen(unencrypted));
-       return strcmp(encrypted, correct) == 0;
+       return r;
 }