openwrt-packages-dist/libs/libpam/patches/005-fix_ruserok.patch

--- a/modules/pam_rhosts/pam_rhosts.c
+++ b/modules/pam_rhosts/pam_rhosts.c
@@ -43,6 +43,361 @@
 #include <security/pam_modutil.h>
 #include <security/pam_ext.h>
 
+#ifdef __UCLIBC__
+
+#include <stdio.h>
+#include <sys/stat.h>
+
+
+int  __check_rhosts_file = 1;
+
+/* Extremely paranoid file open function. */
+static FILE *
+iruserfopen (const char *file, uid_t okuser)
+{
+  struct stat st;
+  char *cp = NULL;
+  FILE *res = NULL;
+
+  /* If not a regular file, if owned by someone other than user or
+     root, if writeable by anyone but the owner, or if hardlinked
+     anywhere, quit.  */
+  if (lstat (file, &st))
+    cp = "lstat failed";
+  else if (!S_ISREG (st.st_mode))
+    cp = "not regular file";
+  else
+    {
+      res = fopen (file, "r");
+      if (!res)
+	cp = "cannot open";
+      else if (fstat (fileno (res), &st) < 0)
+	cp = "fstat failed";
+      else if (st.st_uid && st.st_uid != okuser)
+	cp = "bad owner";
+      else if (st.st_mode & (S_IWGRP|S_IWOTH))
+	cp = "writeable by other than owner";
+      else if (st.st_nlink > 1)
+	cp = "hard linked somewhere";
+    }
+
+  /* If there were any problems, quit.  */
+  if (cp != NULL)
+    {
+      if (res)
+	fclose (res);
+      return NULL;
+    }
+
+  return res;
+}
+
+/*
+ * Returns 1 for blank lines (or only comment lines) and 0 otherwise
+ */
+static int
+__isempty(char *p)
+{
+    while (*p && isspace (*p)) {
+	++p;
+    }
+
+    return (*p == '\0' || *p == '#') ? 1 : 0 ;
+}
+
+/* Returns 1 on positive match, 0 on no match, -1 on negative match.  */
+static int
+__icheckhost (u_int32_t raddr, char *lhost, const char *rhost)
+{
+	struct hostent *hp;
+	u_int32_t laddr;
+	int negate=1;    /* Multiply return with this to get -1 instead of 1 */
+	char **pp;
+
+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
+	int save_errno;
+	size_t buflen;
+	char *buffer;
+	struct hostent hostbuf;
+	int herr;
+#endif
+
+#ifdef HAVE_NETGROUP
+	/* Check nis netgroup.  */
+	if (strncmp ("+@", lhost, 2) == 0)
+		return innetgr (&lhost[2], rhost, NULL, NULL);
+
+	if (strncmp ("-@", lhost, 2) == 0)
+		return -innetgr (&lhost[2], rhost, NULL, NULL);
+#endif /* HAVE_NETGROUP */
+
+	/* -host */
+	if (strncmp ("-", lhost,1) == 0) {
+		negate = -1;
+		lhost++;
+	} else if (strcmp ("+",lhost) == 0) {
+		return 1;                    /* asking for trouble, but ok.. */
+	}
+
+	/* Try for raw ip address first. */
+	if (isdigit (*lhost) && (laddr = inet_addr (lhost)) != INADDR_NONE)
+		return negate * (! (raddr ^ laddr));
+
+	/* Better be a hostname. */
+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
+	buflen = 1024;
+	buffer = malloc(buflen);
+	save_errno = errno;
+
+	while (gethostbyname_r (lhost, &hostbuf, buffer, buflen, &hp, &herr)
+	       != 0) {
+	    free(buffer);
+	    return (0);
+	}
+	free(buffer);
+	__set_errno (save_errno);
+#else
+	hp = gethostbyname(lhost);
+#endif /* __UCLIBC_HAS_REENTRANT_RPC__ */
+
+	if (hp == NULL)
+		return 0;
+
+	/* Spin through ip addresses. */
+	for (pp = hp->h_addr_list; *pp; ++pp)
+		if (!memcmp (&raddr, *pp, sizeof (u_int32_t)))
+			return negate;
+
+	/* No match. */
+	return (0);
+}
+
+/* Returns 1 on positive match, 0 on no match, -1 on negative match.  */
+static int
+__icheckuser (const char *luser, const char *ruser)
+{
+
+    /*
+      luser is user entry from .rhosts/hosts.equiv file
+      ruser is user id on remote host
+      */
+
+#ifdef HAVE_NETGROUP
+    /* [-+]@netgroup */
+    if (strncmp ("+@", luser, 2) == 0)
+	return innetgr (&luser[2], NULL, ruser, NULL);
+
+    if (strncmp ("-@", luser,2) == 0)
+	return -innetgr (&luser[2], NULL, ruser, NULL);
+#endif /* HAVE_NETGROUP */
+
+    /* -user */
+    if (strncmp ("-", luser, 1) == 0)
+	return -(strcmp (&luser[1], ruser) == 0);
+
+    /* + */
+    if (strcmp ("+", luser) == 0)
+	return 1;
+
+    /* simple string match */
+    return strcmp (ruser, luser) == 0;
+}
+
+/*
+ * Returns 0 if positive match, -1 if _not_ ok.
+ */
+static int
+__ivaliduser2(FILE *hostf, u_int32_t raddr,	const char *luser,
+			  const char *ruser, const char *rhost)
+{
+    register const char *user;
+    register char *p;
+    int hcheck, ucheck;
+    char *buf = NULL;
+    size_t bufsize = 0;
+    int retval = -1;
+
+    while (getline (&buf, &bufsize, hostf) > 0) {
+	buf[bufsize - 1] = '\0'; /* Make sure it's terminated.  */
+        p = buf;
+
+	/* Skip empty or comment lines */
+	if (__isempty (p)) {
+	    continue;
+	}
+
+	/* Skip lines that are too long. */
+	if (strchr (p, '\n') == NULL) {
+	    int ch = getc_unlocked (hostf);
+
+	    while (ch != '\n' && ch != EOF)
+	      ch = getc_unlocked (hostf);
+	    continue;
+	}
+
+	for (;*p && !isspace(*p); ++p) {
+	    *p = tolower (*p);
+	}
+
+	/* Next we want to find the permitted name for the remote user.  */
+	if (*p == ' ' || *p == '\t') {
+	    /* <nul> terminate hostname and skip spaces */
+	    for (*p++='\0'; *p && isspace (*p); ++p);
+
+	    user = p;                   /* this is the user's name */
+	    while (*p && !isspace (*p))
+		++p;                    /* find end of user's name */
+	} else
+	    user = p;
+
+	*p = '\0';              /* <nul> terminate username (+host?) */
+
+	/* buf -> host(?) ; user -> username(?) */
+
+	/* First check host part */
+	hcheck = __icheckhost (raddr, buf, rhost);
+
+	if (hcheck < 0)
+	    break;
+
+	if (hcheck) {
+	    /* Then check user part */
+	    if (! (*user))
+		user = luser;
+
+	    ucheck = __icheckuser (user, ruser);
+
+	    /* Positive 'host user' match? */
+	    if (ucheck > 0) {
+		retval = 0;
+		break;
+	    }
+
+	    /* Negative 'host -user' match? */
+	    if (ucheck < 0)
+		break;
+
+	    /* Neither, go on looking for match */
+	}
+    }
+
+    free (buf);
+
+    return retval;
+}
+
+static int
+iruserok2 (u_int32_t raddr, int superuser, const char *ruser, const char *luser,
+		   const char *rhost)
+{
+	FILE *hostf = NULL;
+	int isbad = -1;
+
+	if (!superuser)
+		hostf = iruserfopen (_PATH_HEQUIV, 0);
+
+	if (hostf) {
+		isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
+		fclose (hostf);
+
+		if (!isbad)
+			return 0;
+	}
+
+	if (__check_rhosts_file || superuser) {
+		char *pbuf;
+		struct passwd *pwd;
+		size_t dirlen;
+		uid_t uid;
+
+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
+		size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX);
+		struct passwd pwdbuf;
+		char *buffer = stack_heap_alloc(buflen);
+
+		if (getpwnam_r (luser, &pwdbuf, buffer,
+			    buflen, &pwd) != 0 || pwd == NULL)
+		{
+			stack_heap_free(buffer);
+			return -1;
+		}
+		stack_heap_free(buffer);
+#else
+		if ((pwd = getpwnam(luser)) == NULL)
+			return -1;
+#endif
+
+		dirlen = strlen (pwd->pw_dir);
+		pbuf = malloc (dirlen + sizeof "/.rhosts");
+		strcpy (pbuf, pwd->pw_dir);
+		strcat (pbuf, "/.rhosts");
+
+		/* Change effective uid while reading .rhosts.  If root and
+		   reading an NFS mounted file system, can't read files that
+		   are protected read/write owner only.  */
+		uid = geteuid ();
+		seteuid (pwd->pw_uid);
+		hostf = iruserfopen (pbuf, pwd->pw_uid);
+		free(pbuf);
+
+		if (hostf != NULL) {
+			isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
+			fclose (hostf);
+		}
+
+		seteuid (uid);
+		return isbad;
+	}
+	return -1;
+}
+
+int ruserok(const char *rhost, int superuser, const char *ruser,
+			const char *luser)
+{
+        struct hostent *hp;
+	u_int32_t addr;
+	char **ap;
+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
+	size_t buflen;
+	char *buffer;
+	int herr;
+	struct hostent hostbuf;
+#endif
+
+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
+	buflen = 1024;
+	buffer = stack_heap_alloc(buflen);
+
+	while (gethostbyname_r (rhost, &hostbuf, buffer,
+		    buflen, &hp, &herr) != 0 || hp == NULL)
+	{
+	    if (herr != NETDB_INTERNAL || errno != ERANGE) {
+		stack_heap_free(buffer);
+		return -1;
+	    } else
+	    {
+		/* Enlarge the buffer.  */
+		buflen *= 2;
+		stack_heap_free(buffer);
+		buffer = stack_heap_alloc(buflen);
+	    }
+	}
+	stack_heap_free(buffer);
+#else
+	if ((hp = gethostbyname(rhost)) == NULL) {
+		return -1;
+	}
+#endif
+	for (ap = hp->h_addr_list; *ap; ++ap) {
+		memmove(&addr, *ap, sizeof(addr));
+		if (iruserok2(addr, superuser, ruser, luser, rhost) == 0)
+			return 0;
+	}
+	return -1;
+}
+
+#endif /* __UCLIBC__ */
+
 PAM_EXTERN
 int pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc,
 			 const char **argv)