Message-ID: <20060802191115.GA17703@vino.hallyn.com>
Date:	Wed, 2 Aug 2006 14:11:15 -0500
From:	"Serge E. Hallyn" <serge@...lyn.com>
To:	Chris Wright <chrisw@...s-sol.org>
Cc:	Andrew Morton <akpm@...l.org>,
	Michael Halcrow <mhalcrow@...ibm.com>, serue@...ibm.com,
	Stephen Smalley <sds@...ho.nsa.gov>,
	Davi Arnaut <davi.arnaut@...il.com>, jmorris@...ei.org,
	linux-kernel@...r.kernel.org, linux-security-module@...r.kernel.org
Subject: Re: [PATCH] LSM: remove BSD secure level security module

Quoting Chris Wright (chrisw@...s-sol.org):
> This code has suffered from broken core design and lack of developer
> attention.  Broken security modules are too dangerous to leave around.
> It is time to remove this one.
> 
> Signed-off-by: Chris Wright <chrisw@...s-sol.org>
> Cc: Michael Halcrow <mhalcrow@...ibm.com>
> Cc: Serge Hallyn <serue@...ibm.com>
> Cc: Davi Arnaut <davi.arnaut@...il.com>

Heh.

Acked-by: Serge Hallyn <serue@...ibm.com>

thanks,
-serge

> ---
>  Documentation/seclvl.txt |   97 ------
>  security/Kconfig         |   12
>  security/Makefile        |    1
>  security/seclvl.c        |  669 ----------------------------------------------- 4 files changed, 779 deletions(-)
> 
> diff --git a/Documentation/seclvl.txt b/Documentation/seclvl.txt
> deleted file mode 100644
> index 97274d1..0000000
> --- a/Documentation/seclvl.txt
> +++ /dev/null
> @@ -1,97 +0,0 @@
> -BSD Secure Levels Linux Security Module
> -Michael A. Halcrow <mike@...crow.us>
> -
> -
> -Introduction
> -
> -Under the BSD Secure Levels security model, sets of policies are
> -associated with levels. Levels range from -1 to 2, with -1 being the
> -weakest and 2 being the strongest. These security policies are
> -enforced at the kernel level, so not even the superuser is able to
> -disable or circumvent them. This hardens the machine against attackers
> -who gain root access to the system.
> -
> -
> -Levels and Policies
> -
> -Level -1 (Permanently Insecure):
> - - Cannot increase the secure level
> -
> -Level 0 (Insecure):
> - - Cannot ptrace the init process
> -
> -Level 1 (Default):
> - - /dev/mem and /dev/kmem are read-only
> - - IMMUTABLE and APPEND extended attributes, if set, may not be unset
> - - Cannot load or unload kernel modules
> - - Cannot write directly to a mounted block device
> - - Cannot perform raw I/O operations
> - - Cannot perform network administrative tasks
> - - Cannot setuid any file
> -
> -Level 2 (Secure):
> - - Cannot decrement the system time
> - - Cannot write to any block device, whether mounted or not
> - - Cannot unmount any mounted filesystems
> -
> -
> -Compilation
> -
> -To compile the BSD Secure Levels LSM, seclvl.ko, enable the
> -SECURITY_SECLVL configuration option.  This is found under Security
> -options -> BSD Secure Levels in the kernel configuration menu.
> -
> -
> -Basic Usage
> -
> -Once the machine is in a running state, with all the necessary modules
> -loaded and all the filesystems mounted, you can load the seclvl.ko
> -module:
> -
> -# insmod seclvl.ko
> -
> -The module defaults to secure level 1, except when compiled directly
> -into the kernel, in which case it defaults to secure level 0. To raise
> -the secure level to 2, the administrator writes ``2'' to the
> -seclvl/seclvl file under the sysfs mount point (assumed to be /sys in
> -these examples):
> -
> -# echo -n "2" > /sys/seclvl/seclvl
> -
> -Alternatively, you can initialize the module at secure level 2 with
> -the initlvl module parameter:
> -
> -# insmod seclvl.ko initlvl=2
> -
> -At this point, it is impossible to remove the module or reduce the
> -secure level.  If the administrator wishes to have the option of doing
> -so, he must provide a module parameter, sha1_passwd, that specifies
> -the SHA1 hash of the password that can be used to reduce the secure
> -level to 0.
> -
> -To generate this SHA1 hash, the administrator can use OpenSSL:
> -
> -# echo -n "boogabooga" | openssl sha1
> -abeda4e0f33defa51741217592bf595efb8d289c
> -
> -In order to use password-instigated secure level reduction, the SHA1
> -crypto module must be loaded or compiled into the kernel:
> -
> -# insmod sha1.ko
> -
> -The administrator can then insmod the seclvl module, including the
> -SHA1 hash of the password:
> -
> -# insmod seclvl.ko
> -         sha1_passwd=abeda4e0f33defa51741217592bf595efb8d289c
> -
> -To reduce the secure level, write the password to seclvl/passwd under
> -your sysfs mount point:
> -
> -# echo -n "boogabooga" > /sys/seclvl/passwd
> -
> -The September 2004 edition of Sys Admin Magazine has an article about
> -the BSD Secure Levels LSM.  I encourage you to refer to that article
> -for a more in-depth treatment of this security module:
> -
> -http://www.samag.com/documents/s=9304/sam0409a/0409a.htm
> diff --git a/security/Kconfig b/security/Kconfig
> index 67785df..460e5c9 100644
> --- a/security/Kconfig
> +++ b/security/Kconfig
> @@ -93,18 +93,6 @@ config SECURITY_ROOTPLUG
>  	  
>  	  If you are unsure how to answer this question, answer N.
>  
> -config SECURITY_SECLVL
> -	tristate "BSD Secure Levels"
> -	depends on SECURITY
> -	select CRYPTO
> -	select CRYPTO_SHA1
> -	help
> -	  Implements BSD Secure Levels as an LSM.  See
> -	  <file:Documentation/seclvl.txt> for instructions on how to use this
> -	  module.
> -
> -	  If you are unsure how to answer this question, answer N.
> -
>  source security/selinux/Kconfig
>  
>  endmenu
> diff --git a/security/Makefile b/security/Makefile
> index 8cbbf2f..ef87df2 100644
> --- a/security/Makefile
> +++ b/security/Makefile
> @@ -16,4 +16,3 @@ # Must precede capability.o in order to 
>  obj-$(CONFIG_SECURITY_SELINUX)		+= selinux/built-in.o
>  obj-$(CONFIG_SECURITY_CAPABILITIES)	+= commoncap.o capability.o
>  obj-$(CONFIG_SECURITY_ROOTPLUG)		+= commoncap.o root_plug.o
> -obj-$(CONFIG_SECURITY_SECLVL)		+= seclvl.o
> diff --git a/security/seclvl.c b/security/seclvl.c
> deleted file mode 100644
> index c26dd7d..0000000
> --- a/security/seclvl.c
> +++ /dev/null
> @@ -1,669 +0,0 @@
> -/**
> - * BSD Secure Levels LSM
> - *
> - * Maintainers:
> - *	Michael A. Halcrow <mike@...crow.us>
> - *	Serge Hallyn <hallyn@...wm.edu>
> - *
> - * Copyright (c) 2001 WireX Communications, Inc <chris@...ex.com>
> - * Copyright (c) 2001 Greg Kroah-Hartman <greg@...ah.com>
> - * Copyright (c) 2002 International Business Machines <robb@...tin.ibm.com>
> - * Copyright (c) 2006 Davi E. M. Arnaut <davi.arnaut@...il.com>
> - *
> - *	This program is free software; you can redistribute it and/or modify
> - *	it under the terms of the GNU General Public License as published by
> - *	the Free Software Foundation; either version 2 of the License, or
> - *	(at your option) any later version.
> - */
> -
> -#include <linux/module.h>
> -#include <linux/moduleparam.h>
> -#include <linux/kernel.h>
> -#include <linux/init.h>
> -#include <linux/security.h>
> -#include <linux/netlink.h>
> -#include <linux/fs.h>
> -#include <linux/namei.h>
> -#include <linux/mount.h>
> -#include <linux/capability.h>
> -#include <linux/time.h>
> -#include <linux/proc_fs.h>
> -#include <linux/kobject.h>
> -#include <linux/crypto.h>
> -#include <asm/scatterlist.h>
> -#include <linux/scatterlist.h>
> -#include <linux/gfp.h>
> -#include <linux/sysfs.h>
> -
> -#define SHA1_DIGEST_SIZE 20
> -
> -/**
> - * Module parameter that defines the initial secure level.
> - *
> - * When built as a module, it defaults to seclvl 1, which is the
> - * behavior of BSD secure levels.  Note that this default behavior
> - * wrecks havoc on a machine when the seclvl module is compiled into
> - * the kernel.	In that case, we default to seclvl 0.
> - */
> -#ifdef CONFIG_SECURITY_SECLVL_MODULE
> -static int initlvl = 1;
> -#else
> -static int initlvl;
> -#endif
> -module_param(initlvl, int, 0);
> -MODULE_PARM_DESC(initlvl, "Initial secure level (defaults to 1)");
> -
> -/* Module parameter that defines the verbosity level */
> -static int verbosity;
> -module_param(verbosity, int, 0);
> -MODULE_PARM_DESC(verbosity, "Initial verbosity level (0 or 1; defaults to "
> -		 "0, which is Quiet)");
> -
> -/**
> - * Optional password which can be passed in to bring seclvl to 0
> - * (i.e., for halt/reboot).  Defaults to NULL (the passwd attribute
> - * file will not be registered in sysfs).
> - *
> - * This gets converted to its SHA1 hash when stored.  It's probably
> - * not a good idea to use this parameter when loading seclvl from a
> - * script; use sha1_passwd instead.
> - */
> -
> -#define MAX_PASSWD_SIZE	32
> -static char passwd[MAX_PASSWD_SIZE];
> -module_param_string(passwd, passwd, sizeof(passwd), 0);
> -MODULE_PARM_DESC(passwd,
> -		 "Plaintext of password that sets seclvl=0 when written to "
> -		 "(sysfs mount point)/seclvl/passwd\n");
> -
> -/**
> - * SHA1 hashed version of the optional password which can be passed in
> - * to bring seclvl to 0 (i.e., for halt/reboot).  Must be in
> - * hexadecimal format (40 characters).	Defaults to NULL (the passwd
> - * attribute file will not be registered in sysfs).
> - *
> - * Use the sha1sum utility to generate the SHA1 hash of a password:
> - *
> - * echo -n "secret" | sha1sum
> - */
> -#define MAX_SHA1_PASSWD	41
> -static char sha1_passwd[MAX_SHA1_PASSWD];
> -module_param_string(sha1_passwd, sha1_passwd, sizeof(sha1_passwd), 0);
> -MODULE_PARM_DESC(sha1_passwd,
> -		 "SHA1 hash (40 hexadecimal characters) of password that "
> -		 "sets seclvl=0 when plaintext password is written to "
> -		 "(sysfs mount point)/seclvl/passwd\n");
> -
> -static int hideHash = 1;
> -module_param(hideHash, int, 0);
> -MODULE_PARM_DESC(hideHash, "When set to 0, reading seclvl/passwd from sysfs "
> -		 "will return the SHA1-hashed value of the password that "
> -		 "lowers the secure level to 0.\n");
> -
> -#define MY_NAME "seclvl"
> -
> -/**
> - * This time-limits log writes to one per second.
> - */
> -#define seclvl_printk(verb, type, fmt, arg...)			\
> -	do {							\
> -		if (verbosity >= verb) {			\
> -			static unsigned long _prior;		\
> -			unsigned long _now = jiffies;		\
> -			if ((_now - _prior) > HZ) {		\
> -				printk(type "%s: %s: " fmt,	\
> -					MY_NAME, __FUNCTION__ ,	\
> -					## arg);		\
> -				_prior = _now;			\
> -			}					\
> -		}						\
> -	} while (0)
> -
> -/**
> - * The actual security level.  Ranges between -1 and 2 inclusive.
> - */
> -static int seclvl;
> -
> -/**
> - * flag to keep track of how we were registered
> - */
> -static int secondary;
> -
> -/**
> - * Verifies that the requested secure level is valid, given the current
> - * secure level.
> - */
> -static int seclvl_sanity(int reqlvl)
> -{
> -	if ((reqlvl < -1) || (reqlvl > 2)) {
> -		seclvl_printk(1, KERN_WARNING, "Attempt to set seclvl out of "
> -			      "range: [%d]\n", reqlvl);
> -		return -EINVAL;
> -	}
> -	if ((seclvl == 0) && (reqlvl == -1))
> -		return 0;
> -	if (reqlvl < seclvl) {
> -		seclvl_printk(1, KERN_WARNING, "Attempt to lower seclvl to "
> -			      "[%d]\n", reqlvl);
> -		return -EPERM;
> -	}
> -	return 0;
> -}
> -
> -/**
> - * security level advancement rules:
> - *   Valid levels are -1 through 2, inclusive.
> - *   From -1, stuck.  [ in case compiled into kernel ]
> - *   From 0 or above, can only increment.
> - */
> -static void do_seclvl_advance(void *data, u64 val)
> -{
> -	int ret;
> -	int newlvl = (int)val;
> -
> -	ret = seclvl_sanity(newlvl);
> -	if (ret)
> -		return;
> -
> -	if (newlvl > 2) {
> -		seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
> -			      "[%d]\n", newlvl);
> -		return;
> -	}
> -	if (seclvl == -1) {
> -		seclvl_printk(1, KERN_WARNING, "Not allowed to advance to "
> -			      "seclvl [%d]\n", seclvl);
> -		return;
> -	}
> -	seclvl = newlvl;  /* would it be more "correct" to set *data? */
> -	return;
> -}
> -
> -static u64 seclvl_int_get(void *data)
> -{
> -	return *(int *)data;
> -}
> -
> -DEFINE_SIMPLE_ATTRIBUTE(seclvl_file_ops, seclvl_int_get, do_seclvl_advance, "%lld\n");
> -
> -static unsigned char hashedPassword[SHA1_DIGEST_SIZE];
> -
> -/**
> - * Converts a block of plaintext of into its SHA1 hashed value.
> - *
> - * It would be nice if crypto had a wrapper to do this for us linear
> - * people...
> - */
> -static int
> -plaintext_to_sha1(unsigned char *hash, const char *plaintext, unsigned int len)
> -{
> -	struct crypto_tfm *tfm;
> -	struct scatterlist sg;
> -	if (len > PAGE_SIZE) {
> -		seclvl_printk(0, KERN_ERR, "Plaintext password too large (%d "
> -			      "characters).  Largest possible is %lu "
> -			      "bytes.\n", len, PAGE_SIZE);
> -		return -EINVAL;
> -	}
> -	tfm = crypto_alloc_tfm("sha1", CRYPTO_TFM_REQ_MAY_SLEEP);
> -	if (tfm == NULL) {
> -		seclvl_printk(0, KERN_ERR,
> -			      "Failed to load transform for SHA1\n");
> -		return -EINVAL;
> -	}
> -	sg_init_one(&sg, (u8 *)plaintext, len);
> -	crypto_digest_init(tfm);
> -	crypto_digest_update(tfm, &sg, 1);
> -	crypto_digest_final(tfm, hash);
> -	crypto_free_tfm(tfm);
> -	return 0;
> -}
> -
> -/**
> - * Called whenever the user writes to the sysfs passwd handle to this kernel
> - * object.  It hashes the password and compares the hashed results.
> - */
> -static ssize_t
> -passwd_write_file(struct file * file, const char __user * buf,
> -				size_t count, loff_t *ppos)
> -{
> -	char *p;
> -	int len;
> -	unsigned char tmp[SHA1_DIGEST_SIZE];
> -
> -	if (!*passwd && !*sha1_passwd) {
> -		seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the "
> -			      "seclvl module, but neither a plain text "
> -			      "password nor a SHA1 hashed password was "
> -			      "passed in as a module parameter!  This is a "
> -			      "bug, since it should not be possible to be in "
> -			      "this part of the module; please tell a "
> -			      "maintainer about this event.\n");
> -		return -EINVAL;
> -	}
> -
> -	if (count >= PAGE_SIZE)
> -		return -EINVAL;
> -	if (*ppos != 0)
> -		return -EINVAL;
> -	p = kmalloc(count, GFP_KERNEL);
> -	if (!p)
> -		return -ENOMEM;
> -	len = -EFAULT;
> -	if (copy_from_user(p, buf, count))
> -		goto out;
> -	
> -	len = count;
> -	/* ``echo "secret" > seclvl/passwd'' includes a newline */
> -	if (p[len - 1] == '\n')
> -		len--;
> -	/* Hash the password, then compare the hashed values */
> -	if ((len = plaintext_to_sha1(tmp, p, len))) {
> -		seclvl_printk(0, KERN_ERR, "Error hashing password: rc = "
> -			      "[%d]\n", len);
> -		goto out;
> -	}
> -
> -	len = -EPERM;
> -	if (memcmp(hashedPassword, tmp, SHA1_DIGEST_SIZE))
> -		goto out;
> -
> -	seclvl_printk(0, KERN_INFO,
> -		      "Password accepted; seclvl reduced to 0.\n");
> -	seclvl = 0;
> -	len = count;
> -
> -out:
> -	kfree (p);
> -	return len;
> -}
> -
> -static struct file_operations passwd_file_ops = {
> -	.write = passwd_write_file,
> -};
> -
> -/**
> - * Explicitely disallow ptrace'ing the init process.
> - */
> -static int seclvl_ptrace(struct task_struct *parent, struct task_struct *child)
> -{
> -	if (seclvl >= 0 && child->pid == 1) {
> -		seclvl_printk(1, KERN_WARNING, "Attempt to ptrace "
> -			      "the init process dissallowed in "
> -			      "secure level %d\n", seclvl);
> -		return -EPERM;
> -	}
> -	return 0;
> -}
> -
> -/**
> - * Capability checks for seclvl.  The majority of the policy
> - * enforcement for seclvl takes place here.
> - */
> -static int seclvl_capable(struct task_struct *tsk, int cap)
> -{
> -	int rc = 0;
> -
> -	/* init can do anything it wants */
> -	if (tsk->pid == 1)
> -		return 0;
> -
> -	if (seclvl > 0) {
> -		rc = -EPERM;
> -
> -		if (cap == CAP_LINUX_IMMUTABLE)
> -			seclvl_printk(1, KERN_WARNING, "Attempt to modify "
> -				      "the IMMUTABLE and/or APPEND extended "
> -				      "attribute on a file with the IMMUTABLE "
> -				      "and/or APPEND extended attribute set "
> -				      "denied in seclvl [%d]\n", seclvl);
> -		else if (cap == CAP_SYS_RAWIO)
> -			seclvl_printk(1, KERN_WARNING, "Attempt to perform "
> -				      "raw I/O while in secure level [%d] "
> -				      "denied\n", seclvl);
> -		else if (cap == CAP_NET_ADMIN)
> -			seclvl_printk(1, KERN_WARNING, "Attempt to perform "
> -				      "network administrative task while "
> -				      "in secure level [%d] denied\n", seclvl);
> -		else if (cap == CAP_SETUID)
> -			seclvl_printk(1, KERN_WARNING, "Attempt to setuid "
> -				      "while in secure level [%d] denied\n",
> -				      seclvl);
> -		else if (cap == CAP_SETGID)
> -			seclvl_printk(1, KERN_WARNING, "Attempt to setgid "
> -				      "while in secure level [%d] denied\n",
> -				      seclvl);
> -		else if (cap == CAP_SYS_MODULE)
> -			seclvl_printk(1, KERN_WARNING, "Attempt to perform "
> -				      "a module operation while in secure "
> -				      "level [%d] denied\n", seclvl);
> -		else
> -			rc = 0;
> -	}
> -
> -	if (!rc) {
> -		if (!(cap_is_fs_cap(cap) ? tsk->fsuid == 0 : tsk->euid == 0))
> -			rc = -EPERM;
> -	}
> -
> -	if (rc)
> -		seclvl_printk(1, KERN_WARNING, "Capability denied\n");
> -
> -	return rc;
> -}
> -
> -/**
> - * Disallow reversing the clock in seclvl > 1
> - */
> -static int seclvl_settime(struct timespec *tv, struct timezone *tz)
> -{
> -	if (tv && seclvl > 1) {
> -		struct timespec now;
> -		now = current_kernel_time();
> -		if (tv->tv_sec < now.tv_sec ||
> -		    (tv->tv_sec == now.tv_sec && tv->tv_nsec < now.tv_nsec)) {
> -			seclvl_printk(1, KERN_WARNING, "Attempt to decrement "
> -				      "time in secure level %d denied: "
> -				      "current->pid = [%d], "
> -				      "current->group_leader->pid = [%d]\n",
> -				      seclvl, current->pid,
> -				      current->group_leader->pid);
> -			return -EPERM;
> -		}		/* if attempt to decrement time */
> -	}			/* if seclvl > 1 */
> -	return 0;
> -}
> -
> -/* claim the blockdev to exclude mounters, release on file close */
> -static int seclvl_bd_claim(struct inode *inode)
> -{
> -	int holder;
> -	struct block_device *bdev = NULL;
> -	dev_t dev = inode->i_rdev;
> -	bdev = open_by_devnum(dev, FMODE_WRITE);
> -	if (bdev) {
> -		if (bd_claim(bdev, &holder)) {
> -			blkdev_put(bdev);
> -			return -EPERM;
> -		}
> -		/* claimed, mark it to release on close */
> -		inode->i_security = current;
> -	}
> -	return 0;
> -}
> -
> -/* release the blockdev if you claimed it */
> -static void seclvl_bd_release(struct inode *inode)
> -{
> -	if (inode && S_ISBLK(inode->i_mode) && inode->i_security == current) {
> -		struct block_device *bdev = inode->i_bdev;
> -		if (bdev) {
> -			bd_release(bdev);
> -			blkdev_put(bdev);
> -			inode->i_security = NULL;
> -		}
> -	}
> -}
> -
> -/**
> - * Security for writes to block devices is regulated by this seclvl
> - * function.  Deny all writes to block devices in seclvl 2.  In
> - * seclvl 1, we only deny writes to *mounted* block devices.
> - */
> -static int
> -seclvl_inode_permission(struct inode *inode, int mask, struct nameidata *nd)
> -{
> -	if (current->pid != 1 && S_ISBLK(inode->i_mode) && (mask & MAY_WRITE)) {
> -		switch (seclvl) {
> -		case 2:
> -			seclvl_printk(1, KERN_WARNING, "Write to block device "
> -				      "denied in secure level [%d]\n", seclvl);
> -			return -EPERM;
> -		case 1:
> -			if (seclvl_bd_claim(inode)) {
> -				seclvl_printk(1, KERN_WARNING,
> -					      "Write to mounted block device "
> -					      "denied in secure level [%d]\n",
> -					      seclvl);
> -				return -EPERM;
> -			}
> -		}
> -	}
> -	return 0;
> -}
> -
> -/**
> - * The SUID and SGID bits cannot be set in seclvl >= 1
> - */
> -static int seclvl_inode_setattr(struct dentry *dentry, struct iattr *iattr)
> -{
> -	if (seclvl > 0) {
> -		if (iattr->ia_valid & ATTR_MODE)
> -			if (iattr->ia_mode & S_ISUID ||
> -			    iattr->ia_mode & S_ISGID) {
> -				seclvl_printk(1, KERN_WARNING, "Attempt to "
> -					      "modify SUID or SGID bit "
> -					      "denied in seclvl [%d]\n",
> -					      seclvl);
> -				return -EPERM;
> -			}
> -	}
> -	return 0;
> -}
> -
> -/* release busied block devices */
> -static void seclvl_file_free_security(struct file *filp)
> -{
> -	struct dentry *dentry = filp->f_dentry;
> -
> -	if (dentry)
> -		seclvl_bd_release(dentry->d_inode);
> -}
> -
> -/**
> - * Cannot unmount in secure level 2
> - */
> -static int seclvl_umount(struct vfsmount *mnt, int flags)
> -{
> -	if (current->pid != 1 && seclvl == 2) {
> -		seclvl_printk(1, KERN_WARNING, "Attempt to unmount in secure "
> -			      "level %d\n", seclvl);
> -		return -EPERM;
> -	}
> -	return 0;
> -}
> -
> -static struct security_operations seclvl_ops = {
> -	.ptrace = seclvl_ptrace,
> -	.capable = seclvl_capable,
> -	.inode_permission = seclvl_inode_permission,
> -	.inode_setattr = seclvl_inode_setattr,
> -	.file_free_security = seclvl_file_free_security,
> -	.settime = seclvl_settime,
> -	.sb_umount = seclvl_umount,
> -};
> -
> -/**
> - * Process the password-related module parameters
> - */
> -static int processPassword(void)
> -{
> -	int rc = 0;
> -	if (*passwd) {
> -		char *p;
> -
> -		if (*sha1_passwd) {
> -			seclvl_printk(0, KERN_ERR, "Error: Both "
> -				      "passwd and sha1_passwd "
> -				      "were set, but they are mutually "
> -				      "exclusive.\n");
> -			return -EINVAL;
> -		}
> -
> -		p = kstrdup(passwd, GFP_KERNEL);
> -		if (p == NULL)
> -			return -ENOMEM;
> -
> -		if ((rc = plaintext_to_sha1(hashedPassword, p, strlen(p))))
> -			seclvl_printk(0, KERN_ERR, "Error: SHA1 support not "
> -				      "in kernel\n");
> -
> -		kfree (p);
> -		/* All static data goes to the BSS, which zero's the
> -		 * plaintext password out for us. */
> -	} else if (*sha1_passwd) {	// Base 16
> -		int i;
> -		i = strlen(sha1_passwd);
> -		if (i != (SHA1_DIGEST_SIZE * 2)) {
> -			seclvl_printk(0, KERN_ERR, "Received [%d] bytes; "
> -				      "expected [%d] for the hexadecimal "
> -				      "representation of the SHA1 hash of "
> -				      "the password.\n",
> -				      i, (SHA1_DIGEST_SIZE * 2));
> -			return -EINVAL;
> -		}
> -		while ((i -= 2) + 2) {
> -			unsigned char tmp;
> -			tmp = sha1_passwd[i + 2];
> -			sha1_passwd[i + 2] = '\0';
> -			hashedPassword[i / 2] = (unsigned char)
> -			    simple_strtol(&sha1_passwd[i], NULL, 16);
> -			sha1_passwd[i + 2] = tmp;
> -		}
> -	}
> -	return rc;
> -}
> -
> -/**
> - * securityfs registrations
> - */
> -struct dentry *dir_ino, *seclvl_ino, *passwd_ino;
> -
> -static int seclvlfs_register(void)
> -{
> -	int rc = 0;
> -
> -	dir_ino = securityfs_create_dir("seclvl", NULL);
> -
> -	if (IS_ERR(dir_ino))
> -		return PTR_ERR(dir_ino);
> -
> -	seclvl_ino = securityfs_create_file("seclvl", S_IRUGO | S_IWUSR,
> -				dir_ino, &seclvl, &seclvl_file_ops);
> -	if (IS_ERR(seclvl_ino)) {
> -		rc = PTR_ERR(seclvl_ino);
> -		goto out_deldir;
> -	}
> -	if (*passwd || *sha1_passwd) {
> -		passwd_ino = securityfs_create_file("passwd", S_IRUGO | S_IWUSR,
> -				dir_ino, NULL, &passwd_file_ops);
> -		if (IS_ERR(passwd_ino)) {
> -			rc = PTR_ERR(passwd_ino);
> -			goto out_delf;
> -		}
> -	}
> -	return rc;
> -
> -out_delf:
> -	securityfs_remove(seclvl_ino);
> -
> -out_deldir:
> -	securityfs_remove(dir_ino);
> -
> -	return rc;
> -}
> -
> -static void seclvlfs_unregister(void)
> -{
> -	securityfs_remove(seclvl_ino);
> -
> -	if (*passwd || *sha1_passwd)
> -		securityfs_remove(passwd_ino);
> -
> -	securityfs_remove(dir_ino);
> -}
> -
> -/**
> - * Initialize the seclvl module.
> - */
> -static int __init seclvl_init(void)
> -{
> -	int rc = 0;
> -	static char once;
> -
> -	if (verbosity < 0 || verbosity > 1) {
> -		printk(KERN_ERR "Error: bad verbosity [%d]; only 0 or 1 "
> -		       "are valid values\n", verbosity);
> -		rc = -EINVAL;
> -		goto exit;
> -	}
> -	if (initlvl < -1 || initlvl > 2) {
> -		seclvl_printk(0, KERN_ERR, "Error: bad initial securelevel "
> -			      "[%d].\n", initlvl);
> -		rc = -EINVAL;
> -		goto exit;
> -	}
> -	seclvl = initlvl;
> -	if ((rc = processPassword())) {
> -		seclvl_printk(0, KERN_ERR, "Error processing the password "
> -			      "module parameter(s): rc = [%d]\n", rc);
> -		goto exit;
> -	}
> -
> -	if ((rc = seclvlfs_register())) {
> -		seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n");
> -		goto exit;
> -	}
> -	/* register ourselves with the security framework */
> -	if (register_security(&seclvl_ops)) {
> -		seclvl_printk(0, KERN_ERR,
> -			      "seclvl: Failure registering with the "
> -			      "kernel.\n");
> -		/* try registering with primary module */
> -		rc = mod_reg_security(MY_NAME, &seclvl_ops);
> -		if (rc) {
> -			seclvl_printk(0, KERN_ERR, "seclvl: Failure "
> -				      "registering with primary security "
> -				      "module.\n");
> -			seclvlfs_unregister();
> -			goto exit;
> -		}		/* if primary module registered */
> -		secondary = 1;
> -	}			/* if we registered ourselves with the security framework */
> -
> -	seclvl_printk(0, KERN_INFO, "seclvl: Successfully initialized.\n");
> -
> -	if (once) {
> -		once = 1;
> -		seclvl_printk(0, KERN_INFO, "seclvl is going away. It has been "
> -				"buggy for ages. Also, be warned that "
> -				"Securelevels are useless.");
> -	}
> - exit:
> -	if (rc)
> -		printk(KERN_ERR "seclvl: Error during initialization: rc = "
> -		       "[%d]\n", rc);
> -	return rc;
> -}
> -
> -/**
> - * Remove the seclvl module.
> - */
> -static void __exit seclvl_exit(void)
> -{
> -	seclvlfs_unregister();
> -
> -	if (secondary)
> -		mod_unreg_security(MY_NAME, &seclvl_ops);
> -	else if (unregister_security(&seclvl_ops))
> -		seclvl_printk(0, KERN_INFO,
> -			      "seclvl: Failure unregistering with the "
> -			      "kernel\n");
> -}
> -
> -module_init(seclvl_init);
> -module_exit(seclvl_exit);
> -
> -MODULE_AUTHOR("Michael A. Halcrow <mike@...crow.us>");
> -MODULE_DESCRIPTION("LSM implementation of the BSD Secure Levels");
> -MODULE_LICENSE("GPL");
> -
> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
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