1 files changed, 143 insertions, 0 deletions
diff --git a/crypto/openssh/auth.c b/crypto/openssh/auth.c
new file mode 100644
index 0000000..2ab6e66
--- /dev/null
+++ b/crypto/openssh/auth.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose.  Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ *
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: auth.c,v 1.11 2000/10/11 20:27:23 markus Exp $");
+RCSID("$FreeBSD$");
+
+#include "xmalloc.h"
+#include "rsa.h"
+#include "ssh.h"
+#include "pty.h"
+#include "packet.h"
+#include "buffer.h"
+#include "mpaux.h"
+#include "servconf.h"
+#include "compat.h"
+#include "channels.h"
+#include "match.h"
+
+#include "bufaux.h"
+#include "ssh2.h"
+#include "auth.h"
+#include "session.h"
+
+/* import */
+extern ServerOptions options;
+
+/*
+ * Check if the user is allowed to log in via ssh. If user is listed in
+ * DenyUsers or user's primary group is listed in DenyGroups, false will
+ * be returned. If AllowUsers isn't empty and user isn't listed there, or
+ * if AllowGroups isn't empty and user isn't listed there, false will be
+ * returned.
+ * If the user's shell is not executable, false will be returned.
+ * Otherwise true is returned.
+ */
+int
+allowed_user(struct passwd * pw)
+{
+	struct stat st;
+	struct group *grp;
+	char *shell;
+	int i;
+
+	/* Shouldn't be called if pw is NULL, but better safe than sorry... */
+	if (!pw)
+		return 0;
+
+	/*
+	 * Get the shell from the password data.  An empty shell field is
+	 * legal, and means /bin/sh.
+	 */
+	shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
+
+	/* deny if shell does not exists or is not executable */
+	if (stat(shell, &st) != 0)
+		return 0;
+	if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP))))
+		return 0;
+
+	/* Return false if user is listed in DenyUsers */
+	if (options.num_deny_users > 0) {
+		if (!pw->pw_name)
+			return 0;
+		for (i = 0; i < options.num_deny_users; i++)
+			if (match_pattern(pw->pw_name, options.deny_users[i]))
+				return 0;
+	}
+	/* Return false if AllowUsers isn't empty and user isn't listed there */
+	if (options.num_allow_users > 0) {
+		if (!pw->pw_name)
+			return 0;
+		for (i = 0; i < options.num_allow_users; i++)
+			if (match_pattern(pw->pw_name, options.allow_users[i]))
+				break;
+		/* i < options.num_allow_users iff we break for loop */
+		if (i >= options.num_allow_users)
+			return 0;
+	}
+	/* Get the primary group name if we need it. Return false if it fails */
+	if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
+		grp = getgrgid(pw->pw_gid);
+		if (!grp)
+			return 0;
+
+		/* Return false if user's group is listed in DenyGroups */
+		if (options.num_deny_groups > 0) {
+			if (!grp->gr_name)
+				return 0;
+			for (i = 0; i < options.num_deny_groups; i++)
+				if (match_pattern(grp->gr_name, options.deny_groups[i]))
+					return 0;
+		}
+		/*
+		 * Return false if AllowGroups isn't empty and user's group
+		 * isn't listed there
+		 */
+		if (options.num_allow_groups > 0) {
+			if (!grp->gr_name)
+				return 0;
+			for (i = 0; i < options.num_allow_groups; i++)
+				if (match_pattern(grp->gr_name, options.allow_groups[i]))
+					break;
+			/* i < options.num_allow_groups iff we break for
+			   loop */
+			if (i >= options.num_allow_groups)
+				return 0;
+		}
+	}
+	/* We found no reason not to let this user try to log on... */
+	return 1;
+}