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[src/trunk]: src/share/examples/rump/img2cgd Add a simple proof-of-concept pr...
details: https://anonhg.NetBSD.org/src/rev/83b3fa446635
branches: trunk
changeset: 747303:83b3fa446635
user: pooka <pooka%NetBSD.org@localhost>
date: Tue Sep 08 21:48:25 2009 +0000
description:
Add a simple proof-of-concept program which shows how to use the
kernel cgd driver in an application which encrypts and decrypts
files. The cgd driver is running completely in userspace and
requires no special access privileges.
For example:
golem> dmesg > dmesg.txt
# write encrypted dmesg.txt to encrypted.img
golem> ./img2cgd write encrypted.img dmesg.txt
/cryptfile's passphrase:
# read encrypted.img and output decrypted contents to decrypted.txt
golem> ./img2cgd read encrypted.img decypted.txt
/cryptfile's passphrase:
golem> diff dmesg.txt decypted.txt
# but when entering a different password:
golem> ./img2cgd read encrypted.img decypted.txt
/cryptfile's passphrase:
golem> diff dmesg.txt decypted.txt
Binary files dmesg.txt and decypted.txt differ
Currently the utility writes the data length in a proprietary
format, but I'll convert it to use a real disklabel RSN. Then it
can be used to create cgd-encrypted disk images.
This program can later be used as a base for a utility to create
cgd-encrypted images of a standard NetBSD build. Idea for such a
tool and hence the inspiration for this simple example program from
Roland Dowdeswell.
diffstat:
share/examples/rump/img2cgd/Makefile | 16 ++
share/examples/rump/img2cgd/cgd.conf | 8 +
share/examples/rump/img2cgd/cgd_rumpops.c | 49 ++++++
share/examples/rump/img2cgd/img2cgd.c | 216 ++++++++++++++++++++++++++++++
4 files changed, 289 insertions(+), 0 deletions(-)
diffs (truncated from 305 to 300 lines):
diff -r 6eb0c434a377 -r 83b3fa446635 share/examples/rump/img2cgd/Makefile
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/share/examples/rump/img2cgd/Makefile Tue Sep 08 21:48:25 2009 +0000
@@ -0,0 +1,16 @@
+PROG= img2cgd
+SRCS= img2cgd.c cgd_rumpops.c
+NOMAN=
+
+.include <bsd.own.mk>
+
+.include "${NETBSDSRCDIR}/sbin/cgdconfig/Makefile.cgdconfig"
+
+LDADD+= -lrumpdev_cgd -lrumpdev_disk -lrumpdev -lrumpcrypto
+LDADD+= -lrumpvfs -lrump -lrumpuser -lpthread
+
+CPPFLAGS+= -DCGDCONFIG_AS_LIB
+
+DBG=-g -O0
+
+.include <bsd.prog.mk>
diff -r 6eb0c434a377 -r 83b3fa446635 share/examples/rump/img2cgd/cgd.conf
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/share/examples/rump/img2cgd/cgd.conf Tue Sep 08 21:48:25 2009 +0000
@@ -0,0 +1,8 @@
+algorithm aes-cbc;
+iv-method encblkno1;
+keylength 128;
+verify_method none;
+keygen pkcs5_pbkdf2/sha1 {
+ iterations 42;
+ salt AAAAgGP2NZIYEnyKYALLRmdZdZc=;
+};
diff -r 6eb0c434a377 -r 83b3fa446635 share/examples/rump/img2cgd/cgd_rumpops.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/share/examples/rump/img2cgd/cgd_rumpops.c Tue Sep 08 21:48:25 2009 +0000
@@ -0,0 +1,49 @@
+/* $NetBSD: cgd_rumpops.c,v 1.1 2009/09/08 21:48:25 pooka Exp $ */
+
+/*
+ * Copyright (c) 2009 The NetBSD Foundation, Inc.
+ * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``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 FOUNDATION OR CONTRIBUTORS
+ * 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 <sys/cdefs.h>
+#ifndef lint
+__RCSID("$NetBSD: cgd_rumpops.c,v 1.1 2009/09/08 21:48:25 pooka Exp $");
+#endif /* !lint */
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <rump/rump_syscalls.h>
+
+#include "cgd_kernelops.h"
+
+const struct cgd_kernelops cgd_kops = {
+ .ko_open = rump_sys_open,
+ .ko_ioctl = rump_sys_ioctl,
+ .ko_pread = rump_sys_pread,
+ .ko_close = rump_sys_close,
+};
diff -r 6eb0c434a377 -r 83b3fa446635 share/examples/rump/img2cgd/img2cgd.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/share/examples/rump/img2cgd/img2cgd.c Tue Sep 08 21:48:25 2009 +0000
@@ -0,0 +1,216 @@
+/* $NetBSD: img2cgd.c,v 1.1 2009/09/08 21:48:25 pooka Exp $ */
+
+/*
+ * Copyright (c) 2009 Antti Kantee. 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 OR CONTRIBUTORS 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 <sys/types.h>
+#include <sys/param.h>
+
+#include <assert.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rump/rump.h>
+#include <rump/rump_syscalls.h>
+
+/*
+ * We really should use disklabel. However, for the time being,
+ * use a endian independent magic number at offset == 0 and a
+ * 64bit size at offset == 8.
+ */
+#define MYMAGIC 0x11000a00000a0011LL
+#define MAGOFF 0
+#define SIZEOFF 8
+
+#define SKIPLABEL 8192
+#define IMG_MINSIZE (128*1024) /* label/mbr/etc search looks here and there */
+
+static void
+usage(void)
+{
+
+ fprintf(stderr, "usage: %s read|write cgd_image file\n", getprogname());
+ exit(1);
+}
+
+typedef ssize_t (*readfn)(int, void *, size_t);
+typedef ssize_t (*writefn)(int, const void *, size_t);
+
+#define BLOCKSIZE 512
+#define BLKROUND(a) (((a)+(BLOCKSIZE-1)) & ~(BLOCKSIZE-1))
+
+static void
+doxfer(int fd_from, int fd_to, off_t nbytes, readfn rfn, writefn wfn,
+ int roundwrite)
+{
+ char buf[8192];
+ ssize_t n;
+
+ assert(sizeof(buf) % BLOCKSIZE == 0);
+ if (roundwrite)
+ nbytes = BLKROUND(nbytes);
+
+ memset(buf, 0, sizeof(buf));
+ while (nbytes) {
+ n = rfn(fd_from, buf, sizeof(buf));
+ if (n == -1)
+ err(1, "read");
+ if (n == 0)
+ break;
+ n = MIN(n, nbytes);
+ if (roundwrite)
+ n = BLKROUND(n);
+ nbytes -= n;
+ if (wfn(fd_to, buf, n) == -1)
+ err(1, "write");
+ }
+}
+
+#define RFLAGS (O_RDONLY)
+#define WFLAGS (O_WRONLY | O_CREAT | O_TRUNC)
+int
+main(int argc, char *argv[])
+{
+ const char *the_argv[10];
+ const char *cgd_file, *img_file;
+ struct stat sb_cgd, sb_file;
+ off_t nbytes;
+ int error;
+ int fd, fd_r;
+ int readmode;
+
+ setprogname(argv[0]);
+
+ if (argc != 4)
+ usage();
+
+ if (strcmp(argv[1], "read") == 0)
+ readmode = 1;
+ else if (strcmp(argv[1], "write") == 0)
+ readmode = 0;
+ else
+ usage();
+
+ cgd_file = argv[2];
+ img_file = argv[3];
+
+ if (stat(img_file, &sb_file) == -1) {
+ if (!readmode)
+ err(1, "cannot open file image %s", img_file);
+ } else {
+ if (!S_ISREG(sb_file.st_mode))
+ errx(1, "%s is not a regular file", img_file);
+ }
+
+ if (stat(cgd_file, &sb_cgd) == -1) {
+ if (readmode)
+ err(1, "cannot open cgd image %s", cgd_file);
+ } else {
+ if (!S_ISREG(sb_cgd.st_mode))
+ errx(1, "%s is not a regular file", cgd_file);
+ }
+
+ /*
+ * Create a file big enough to hold the file we are encrypting.
+ * This is because cgd works on a device internally and does
+ * not know how to enlarge a device (surprisingly ...).
+ */
+ if (!readmode) {
+ uint64_t tmpval;
+
+ fd = open(cgd_file, WFLAGS, 0755);
+ if (fd == -1)
+ err(1, "fd");
+ ftruncate(fd,
+ MAX(IMG_MINSIZE, BLKROUND(sb_file.st_size)) + SKIPLABEL);
+
+ /* write magic info */
+ tmpval = MYMAGIC;
+ if (pwrite(fd, &tmpval, 8, MAGOFF) != 8)
+ err(1, "magic write failed");
+ tmpval = htole64(sb_file.st_size);
+ if (pwrite(fd, &tmpval, 8, SIZEOFF) != 8)
+ err(1, "size write failed");
+
+ close(fd);
+
+ nbytes = sb_file.st_size;
+ } else {
+ uint64_t tmpval;
+
+ fd = open(cgd_file, RFLAGS);
+ if (fd == -1)
+ err(1, "image open failed");
+
+ if (pread(fd, &tmpval, 8, MAGOFF) != 8)
+ err(1, "magic read failed");
+ if (tmpval != MYMAGIC)
+ errx(1, "%s is not a valid image", img_file);
+ if (pread(fd, &tmpval, 8, SIZEOFF) != 8)
+ errx(1, "size read failed");
+ close(fd);
+
+ nbytes = le64toh(tmpval);
+ }
+
+ rump_init();
+ if ((error = rump_etfs_register("/cryptfile", cgd_file,
+ RUMP_ETFS_BLK)) != 0) {
+ printf("etfs: %d\n", error);
+ exit(1);
+ }
+
+ the_argv[0] = "cgdconfig";
+ the_argv[1] = "cgd0";
+ the_argv[2] = "/cryptfile";
+ the_argv[3] = "./cgd.conf";
+ the_argv[4] = NULL;
+ error = cgdconfig(4, the_argv);
+ if (error) {
+ fprintf(stderr, "cgdconfig failed: %d (%s)\n",
+ error, strerror(error));
+ exit(1);
+ }
+
+ fd = open(img_file, readmode ? WFLAGS : RFLAGS, 0755);
+ if (fd == -1)
+ err(1, "fd");
+ fd_r = rump_sys_open("/dev/rcgd0d", O_RDWR, 0755);
+ if (fd_r == -1)
+ err(1, "fd_r");
+ if (rump_sys_lseek(fd_r, SKIPLABEL, SEEK_SET) == -1)
+ err(1, "rump lseek");
+
+ if (readmode) {
+ doxfer(fd_r, fd, nbytes, rump_sys_read, write, 0);
+ } else {
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