[bug-inetutils] fix for: 1.4.2 rexecd doesn't handle shadow passwords

[Andrew Klossner]

rexecd.c only understands passwords from /etc/passwd, it doesn't know
about /etc/shadow.  You could argue that anyone who cares about
shadowing passwords has no business using rexecd in the first place,
but it makes sense for a project I support.  The enclosed patch
teaches rexecd about shadows.

*** inetutils-1.4.2/rexecd/old-rexecd.c Wed Dec 11 04:38:00 2002
--- inetutils-1.4.2/rexecd/rexecd.c     Fri Mar 19 16:04:14 2004
***************
*** 79,84 ****
--- 79,88 ----
  #include <varargs.h>
  #endif
  
+ #ifdef HAVE_SHADOW_H
+ #include <shadow.h>
+ #endif
+ 
  void error __P ((const char *fmt, ...));
  /*
   * remote execute server:
***************
*** 127,132 ****
--- 131,140 ----
        char *cmdbuf, *cp, *namep;
        char *user, *pass;
        struct passwd *pwd;
+ #ifdef HAVE_SHADOW_H
+       struct spwd *spwd;
+       char *pw_field;
+ #endif
        int s;
        u_short port;
        int pv[2], pid, cc;
***************
*** 186,191 ****
--- 194,217 ----
                exit(1);
        }
        endpwent();
+ 
+ #ifdef HAVE_SHADOW_H
+       // Get encrypted password from /etc/shadow if possible,
+       // else from /etc/passwd.
+       spwd = getspnam(user);
+       if (spwd) {
+               pw_field = spwd->sp_pwdp;
+       } else {
+               pw_field = pwd->pw_passwd;
+       }
+       if (*pw_field != '\0') {
+               namep = CRYPT (pass, pw_field);
+               if (strcmp(namep, pw_field)) {
+                       error("Password incorrect.\n");
+                       exit(1);
+               }
+       }
+ #else
        if (*pwd->pw_passwd != '\0') {
                namep = CRYPT (pass, pwd->pw_passwd);
                if (strcmp(namep, pwd->pw_passwd)) {
***************
*** 193,198 ****
--- 219,225 ----
                        exit(1);
                }
        }
+ #endif
        write(STDERR_FILENO, "\0", 1);
        if (port) {
                pipe(pv);