remove echo_main -> bb_echo indirection

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

diff --git a/libbb/correct_password.c b/libbb/correct_password.c
index 570aa7e86fca02d7323da1b2903c1ccce54446b4..96bb10e0b465f83be79eb1e1a22a557771a898c4 100644 (file)
--- a/libbb/correct_password.c
+++ b/libbb/correct_password.c
@@ -28,50 +28,50 @@
  * SUCH DAMAGE.
  */
 
-#include <stdio.h>
-#include <errno.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
-#include <syslog.h>
-#include <ctype.h>
-#include <crypt.h>
-
 #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 correct_password(const struct passwd *pw)
 {
-       char *unencrypted, *encrypted, *correct;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-       if (( strcmp ( pw-> pw_passwd, "x" ) == 0 ) || ( strcmp ( pw-> pw_passwd, "*" ) == 0 )) {
-               struct spwd *sp = getspnam ( pw-> pw_name );
-
-               if ( !sp )
-                       bb_error_msg_and_die ( "no valid shadow password" );
+       char *unencrypted, *encrypted;
+       const char *correct;
+#if ENABLE_FEATURE_SHADOWPASSWDS
+       /* Using _r function to avoid pulling in static buffers */
+       struct spwd spw;
+       char buffer[256];
+#endif
 
-               correct = sp-> sp_pwdp;
+       /* 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 ((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;
+               int r = getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result);
+               correct = (r || !result) ? "aa" : result->sp_pwdp;
        }
-       else
 #endif
-       correct = pw-> pw_passwd;
 
-       if ( correct == 0 || correct[0] == '\0' )
+       if (!correct[0]) /* empty password field? */
                return 1;
 
-       unencrypted = bb_askpass ( 0, "Password: " );
-       if ( !unencrypted )
-       {
+ fake_it:
+       unencrypted = bb_askpass(0, "Password: ");
+       if (!unencrypted) {
                return 0;
        }
-       encrypted = crypt ( unencrypted, correct );
-       memset ( unencrypted, 0, bb_strlen ( unencrypted ));
-       return ( strcmp ( encrypted, correct ) == 0 ) ? 1 : 0;
+       encrypted = crypt(unencrypted, correct);
+       memset(unencrypted, 0, strlen(unencrypted));
+       return strcmp(encrypted, correct) == 0;
 }