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Add loop-AES compatible handling code.

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git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@418 36d66b0a-2a48-0410-832c-cd162a569da5
This commit is contained in:
Milan Broz
2011-01-25 18:48:56 +00:00
parent 49937ac591
commit 044cb58588
10 changed files with 422 additions and 8 deletions
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4
ChangeLog
View File

@@ -1,3 +1,7 @@
2011-01-25 Milan Broz <mbroz@redhat.com>
* Add loop-AES handling (loopaesOpen and loopaesClose commands).
(requires kernel 2.6.38 and above)
2011-01-05 Milan Broz <mbroz@redhat.com>
* Fix static build (--disable-static-cryptsetup now works properly).

1
configure.in
View File

@@ -257,6 +257,7 @@ lib/Makefile
lib/libcryptsetup.pc
lib/crypto_backend/Makefile
lib/luks1/Makefile
lib/loopaes/Makefile
src/Makefile
po/Makefile.in
man/Makefile

14
lib/Makefile.am
View File

@@ -1,4 +1,4 @@
SUBDIRS = crypto_backend luks1
SUBDIRS = crypto_backend luks1 loopaes
moduledir = $(libdir)/cryptsetup
@@ -9,6 +9,7 @@ INCLUDES = \
-I$(top_srcdir) \
-I$(top_srcdir)/lib/crypto_backend \
-I$(top_srcdir)/lib/luks1 \
-I$(top_srcdir)/lib/loopaes \
-DDATADIR=\""$(datadir)"\" \
-DLIBDIR=\""$(libdir)"\" \
-DPREFIX=\""$(prefix)"\" \
@@ -20,7 +21,12 @@ INCLUDES = \
lib_LTLIBRARIES = libcryptsetup.la
libcryptsetup_la_DEPENDENCIES = libcryptsetup.sym
common_ldadd = \
crypto_backend/libcrypto_backend.la \
luks1/libluks1.la \
loopaes/libloopaes.la
libcryptsetup_la_DEPENDENCIES = $(common_ldadd) libcryptsetup.sym
libcryptsetup_la_LDFLAGS = \
-Wl,--version-script=$(top_srcdir)/lib/libcryptsetup.sym \
@@ -32,8 +38,8 @@ libcryptsetup_la_LIBADD = \
@UUID_LIBS@ \
@DEVMAPPER_LIBS@ \
@CRYPTO_LIBS@ \
crypto_backend/libcrypto_backend.la \
luks1/libluks1.la
$(common_ldadd)
libcryptsetup_la_SOURCES = \
setup.c \

5
lib/libcryptsetup.h
View File

@@ -146,6 +146,7 @@ int crypt_memory_lock(struct crypt_device *cd, int lock);
#define CRYPT_PLAIN "PLAIN" /* regular crypt device, no on-disk header */
#define CRYPT_LUKS1 "LUKS1" /* LUKS version 1 header on-disk */
#define CRYPT_LOOPAES "LOOPAES" /* loop-AES compatibility mode */
/**
* Get device type
@@ -167,6 +168,10 @@ struct crypt_params_luks1 {
size_t data_alignment; /* in sectors, data offset is multiple of this */
};
struct crypt_params_loopaes {
const char *hash; /* key hash function */
uint64_t offset; /* offset in sectors */
};
/**
* Create (format) new crypt device (and possible header on-disk) but not activates it.
*

16
lib/loopaes/Makefile.am Normal file
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@@ -0,0 +1,16 @@
moduledir = $(libdir)/cryptsetup
noinst_LTLIBRARIES = libloopaes.la
libloopaes_la_CFLAGS = -Wall @CRYPTO_CFLAGS@
libloopaes_la_SOURCES = \
loopaes.c \
loopaes.h
INCLUDES = -D_GNU_SOURCE \
-D_LARGEFILE64_SOURCE \
-D_FILE_OFFSET_BITS=64 \
-I$(top_srcdir)/lib \
-I$(top_srcdir)/lib/crypto_backend

216
lib/loopaes/loopaes.c Normal file
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@@ -0,0 +1,216 @@
/*
* loop-AES compatible volume handling
*
* Copyright (C) 2011, Red Hat, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "crypto_backend.h"
#include "loopaes.h"
static const char *get_hash(unsigned int key_size)
{
char *hash;
switch (key_size) {
case 16: hash = "sha256"; break;
case 24: hash = "sha384"; break;
case 32: hash = "sha512"; break;
default: hash = NULL;
}
return hash;
}
static unsigned char get_tweak(unsigned int keys_count)
{
switch (keys_count) {
case 64: return 0x55;
case 65: return 0xF4;
default: break;
}
return 0x00;
}
static int hash_key(const char *src, size_t src_len,
char *dst, size_t dst_len,
const char *hash_name)
{
struct crypt_hash *hd = NULL;
if (crypt_hash_init(&hd, hash_name))
return -EINVAL;
crypt_hash_write(hd, src, src_len);
crypt_hash_final(hd, dst, dst_len);
crypt_hash_destroy(hd);
return 0;
}
static int hash_keys(struct volume_key **vk,
const char **input_keys,
unsigned int keys_count,
unsigned int key_len_output)
{
const char *hash_name;
char tweak, *key_ptr;
int r, i, key_len_input;
hash_name = get_hash(key_len_output);
tweak = get_tweak(keys_count);
key_len_input = strlen(input_keys[0]);
if (!keys_count || !key_len_output || !hash_name || !key_len_input)
return -EINVAL;
*vk = crypt_alloc_volume_key(key_len_output * keys_count, NULL);
if (!*vk)
return -ENOMEM;
for (i = 0; i < keys_count; i++) {
key_ptr = &(*vk)->key[i * key_len_output];
r = hash_key(input_keys[i], key_len_input, key_ptr,
key_len_output, hash_name);
if (r < 0)
break;
key_ptr[0] ^= tweak;
}
if (r < 0 && *vk) {
crypt_free_volume_key(*vk);
*vk = NULL;
}
return r;
}
static int keyfile_is_gpg(char *buffer, unsigned int buffer_len)
{
int r = 0;
int index = buffer_len < 100 ? buffer_len - 1 : 100;
char eos = buffer[index];
buffer[index] = '\0';
if (strstr(buffer, "BEGIN PGP MESSAGE"))
r = 1;
buffer[index] = eos;
return r;
}
int LOOPAES_parse_keyfile(struct crypt_device *cd,
struct volume_key **vk,
unsigned int *keys_count,
char *buffer,
unsigned int buffer_len)
{
const char *keys[LOOPAES_KEYS_MAX];
int i, key_index, key_len, offset;
log_dbg("Parsing loop-AES keyfile of size %d.", buffer_len);
if (buffer_len < LOOPAES_KEYFILE_MINSIZE) {
log_err(cd, _("Incompatible loop-AES keyfile detected.\n"));
return -EINVAL;
}
if (keyfile_is_gpg(buffer, buffer_len)) {
log_err(cd, "Detected not yet supported GPG encrypted keyfile.\n");
log_std(cd, "Please use gpg --decrypt <KEYFILE> | cryptsetup --keyfile=- ...\n");
return -EINVAL;
}
/* Remove EOL in buffer */
for (i = 0; i < buffer_len; i++)
if (buffer[i] == '\n' || buffer[i] == '\r')
buffer[i] = '\0';
offset = 0;
key_index = 0;
while (offset < buffer_len && key_index < LOOPAES_KEYS_MAX) {
keys[key_index++] = &buffer[offset];
while (offset < buffer_len && buffer[offset])
offset++;
while (offset < buffer_len && !buffer[offset])
offset++;
}
/* All keys must be the same length */
key_len = key_index ? strlen(keys[0]) : 0;
for (i = 0; i < key_index; i++)
if (key_len != strlen(keys[i])) {
log_dbg("Unexpected length %d of key #%d (should be %d).",
strlen(keys[i]), i, key_len);
key_len = 0;
break;
}
log_dbg("Keyfile: %d keys of length %d.", key_index, key_len);
if (offset != buffer_len || key_len == 0 ||
(key_index != 1 && key_index !=64 && key_index != 65)) {
log_err(cd, _("Incompatible loop-AES keyfile detected.\n"));
return -EINVAL;
}
*keys_count = key_index;
return hash_keys(vk, keys, key_index, crypt_get_volume_key_size(cd));
}
int LOOPAES_activate(struct crypt_device *cd,
const char *name,
const char *base_cipher,
unsigned int keys_count,
struct volume_key *vk,
uint32_t flags)
{
uint64_t size, offset;
char *cipher;
const char *device;
int read_only, r;
size = 0;
offset = crypt_get_data_offset(cd);
device = crypt_get_device_name(cd);
read_only = flags & CRYPT_ACTIVATE_READONLY;
r = device_check_and_adjust(cd, device, 1, &size, &offset, &read_only);
if (r)
return r;
if (keys_count == 1) {
if (asprintf(&cipher, "%s-%s", base_cipher, "cbc-plain") < 0)
return -ENOMEM;
} else {
if (!(dm_flags() & DM_LMK_SUPPORTED)) {
log_err(cd, _("Kernel doesn't support loop-AES compatible mapping.\n"));
return -ENOTSUP;
}
if (asprintf(&cipher, "%s:%d-%s", base_cipher, 64, "cbc-lmk") < 0)
return -ENOMEM;
}
log_dbg("Trying to activate loop-AES device %s using cipher %s.", name, cipher);
r = dm_create_device(name, device,
cipher, CRYPT_LOOPAES,
crypt_get_uuid(cd),
size, 0, offset, vk->keylength, vk->key,
read_only, 0);
free(cipher);
return r;
}

22
lib/loopaes/loopaes.h Normal file
View File

@@ -0,0 +1,22 @@
#ifndef _LOOPAES_H
#define _LOOPAES_H
#define LOOPAES_KEYS_MAX 65
#define LOOPAES_KEYFILE_MINSIZE 60
#define LOOPAES_KEYFILE_MAXSIZE 8000
#define DEFAULT_LOOPAES_CIPHER "aes"
int LOOPAES_parse_keyfile(struct crypt_device *cd,
struct volume_key **vk,
unsigned int *keys_count,
char *buffer,
unsigned int buffer_len);
int LOOPAES_activate(struct crypt_device *cd,
const char *name,
const char *base_cipher,
unsigned int keys_count,
struct volume_key *vk,
uint32_t flags);
#endif

92
lib/setup.c
View File

@@ -7,6 +7,7 @@
#include "libcryptsetup.h"
#include "luks.h"
#include "loopaes.h"
#include "internal.h"
#include "crypto_backend.h"
@@ -31,6 +32,13 @@ struct crypt_device {
char *plain_cipher_mode;
char *plain_uuid;
/* used in CRYPT_LOOPAES */
struct crypt_params_loopaes loopaes_hdr;
char *loopaes_cipher;
char *loopaes_cipher_mode;
char *loopaes_uuid;
unsigned int loopaes_key_size;
/* callbacks definitions */
void (*log)(int level, const char *msg, void *usrptr);
void *log_usrptr;
@@ -160,6 +168,11 @@ static int isLUKS(const char *type)
return (type && !strcmp(CRYPT_LUKS1, type));
}
static int isLOOPAES(const char *type)
{
return (type && !strcmp(CRYPT_LOOPAES, type));
}
/* keyslot helpers */
static int keyslot_verify_or_find_empty(struct crypt_device *cd, int *keyslot)
{
@@ -991,7 +1004,7 @@ int crypt_init_by_name(struct crypt_device **cd, const char *name)
char *device = NULL, *cipher_full = NULL, *device_uuid = NULL;
char cipher[MAX_CIPHER_LEN], cipher_mode[MAX_CIPHER_LEN];
char *key = NULL;
int key_size = 0, r;
int key_size = 0, key_nums, r;
log_dbg("Allocating crypt device context by device %s.", name);
@@ -1040,6 +1053,21 @@ int crypt_init_by_name(struct crypt_device **cd, const char *name)
(*cd)->plain_cipher = strdup(cipher);
(*cd)->plain_cipher_mode = strdup(cipher_mode);
}
} else if (!strncmp(CRYPT_LOOPAES, device_uuid, sizeof(CRYPT_LOOPAES)-1)) {
(*cd)->type = strdup(CRYPT_LOOPAES);
(*cd)->loopaes_uuid = strdup(device_uuid);
(*cd)->loopaes_hdr.offset = cad.offset;
r = crypt_parse_name_and_mode(cipher_full, cipher,
&key_nums, cipher_mode);
if (!r) {
(*cd)->loopaes_cipher = strdup(cipher);
(*cd)->loopaes_cipher_mode = strdup(cipher_mode);
/* version 3 uses last key for IV */
if (key_size % key_nums)
key_nums++;
(*cd)->loopaes_key_size = key_size / key_nums;
}
} else if (!strncmp(CRYPT_LUKS1, device_uuid, sizeof(CRYPT_LUKS1)-1)) {
if (device) {
if (crypt_load(*cd, CRYPT_LUKS1, NULL) < 0 ||
@@ -1168,6 +1196,37 @@ static int _crypt_format_luks1(struct crypt_device *cd,
return r;
}
static int _crypt_format_loopaes(struct crypt_device *cd,
const char *cipher,
const char *uuid,
size_t volume_key_size,
struct crypt_params_loopaes *params)
{
if (!cd->device) {
log_err(cd, _("Can't format LOOPAES without device.\n"));
return -EINVAL;
}
if (volume_key_size > 1024) {
log_err(cd, _("Invalid key size.\n"));
return -EINVAL;
}
cd->loopaes_key_size = volume_key_size;
cd->loopaes_cipher = strdup(cipher ?: DEFAULT_LOOPAES_CIPHER);
if (uuid)
cd->loopaes_uuid = strdup(uuid);
if (params && params->hash)
cd->loopaes_hdr.hash = strdup(params->hash);
cd->loopaes_hdr.offset = params ? params->offset : 0;
return 0;
}
int crypt_format(struct crypt_device *cd,
const char *type,
const char *cipher,
@@ -1194,6 +1253,8 @@ int crypt_format(struct crypt_device *cd,
else if (isLUKS(type))
r = _crypt_format_luks1(cd, cipher, cipher_mode,
uuid, volume_key, volume_key_size, params);
else if (isLOOPAES(type))
r = _crypt_format_loopaes(cd, cipher, uuid, volume_key_size, params);
else {
/* FIXME: allow plugins here? */
log_err(cd, _("Unknown crypt device type %s requested.\n"), type);
@@ -1815,7 +1876,7 @@ int crypt_activate_by_keyfile(struct crypt_device *cd,
crypt_status_info ci;
struct volume_key *vk = NULL;
char *passphrase_read = NULL;
unsigned int passphrase_size_read;
unsigned int passphrase_size_read, key_count = 0;
int r;
log_dbg("Activating volume %s [keyslot %d] using keyfile %s.",
@@ -1863,6 +1924,18 @@ int crypt_activate_by_keyfile(struct crypt_device *cd,
goto out;
}
r = keyslot;
} else if (isLOOPAES(cd->type)) {
r = key_from_file(cd, NULL, &passphrase_read, &passphrase_size_read,
keyfile, LOOPAES_KEYFILE_MAXSIZE);
if (r < 0)
goto out;
r = LOOPAES_parse_keyfile(cd, &vk, &key_count,
passphrase_read, passphrase_size_read);
if (r < 0)
goto out;
if (name)
r = LOOPAES_activate(cd, name, cd->loopaes_cipher,
key_count, vk, flags);
} else
r = -EINVAL;
@@ -2185,6 +2258,9 @@ const char *crypt_get_cipher(struct crypt_device *cd)
if (isLUKS(cd->type))
return cd->hdr.cipherName;
if (isLOOPAES(cd->type))
return cd->loopaes_cipher;
return NULL;
}
@@ -2196,6 +2272,9 @@ const char *crypt_get_cipher_mode(struct crypt_device *cd)
if (isLUKS(cd->type))
return cd->hdr.cipherMode;
if (isLOOPAES(cd->type))
return cd->loopaes_cipher_mode;
return NULL;
}
@@ -2207,6 +2286,9 @@ const char *crypt_get_uuid(struct crypt_device *cd)
if (isPLAIN(cd->type))
return cd->plain_uuid;
if (isLOOPAES(cd->type))
return cd->loopaes_uuid;
return NULL;
}
@@ -2223,6 +2305,9 @@ int crypt_get_volume_key_size(struct crypt_device *cd)
if (isLUKS(cd->type))
return cd->hdr.keyBytes;
if (isLOOPAES(cd->type))
return cd->loopaes_key_size;
return 0;
}
@@ -2234,6 +2319,9 @@ uint64_t crypt_get_data_offset(struct crypt_device *cd)
if (isLUKS(cd->type))
return cd->hdr.payloadOffset;
if (isLOOPAES(cd->type))
return cd->loopaes_hdr.offset;
return 0;
}

20
man/cryptsetup.8
View File

@@ -134,6 +134,26 @@ This command allows restoring header if device do not contain LUKS header or if
For more information about LUKS, see \fBhttp://code.google.com/p/cryptsetup/wiki/Specification\fR
.SH Loop-AES EXTENSION
cryptsetup allows to map loop-AES encrypted partition using compatible dm-crypt mode.
.PP
\fIloopaesOpen\fR <device> <name> \-\-key-file <keyfile>
.IP
opens the loop-AES <device> and sets up a mapping <name>.
N.B. If keyfile is in GPG encrypted format, you have to use \-\-key-file=- and decrypt it before use.
gpg --decrypt <keyfile> | cryptsetup loopaesOpen \-\-key-file=- <device> <name>
\fB<options>\fR can be [\-\-key-file, \-\-key-size, \-\-offset, \-\-readonly].
.PP
\fIloopaesClose\fR <name>
.IP
identical to \fIremove\fR.
.PP
For more information about loop-AES, see \fBhttp://loop-aes.sourceforge.net\fR
.SH OPTIONS
.TP
.B "\-\-verbose, \-v"

40
src/cryptsetup.c
View File

@@ -62,6 +62,7 @@ static int action_luksSuspend(int arg);
static int action_luksResume(int arg);
static int action_luksBackup(int arg);
static int action_luksRestore(int arg);
static int action_loopaesOpen(int arg);
static struct action_type {
const char *type;
@@ -89,6 +90,8 @@ static struct action_type {
{ "luksResume", action_luksResume, 0, 1, 1, N_("<device>"), N_("Resume suspended LUKS device.") },
{ "luksHeaderBackup",action_luksBackup, 0, 1, 1, N_("<device>"), N_("Backup LUKS device header and keyslots") },
{ "luksHeaderRestore",action_luksRestore,0,1, 1, N_("<device>"), N_("Restore LUKS device header and keyslots") },
{ "loopaesOpen",action_loopaesOpen, 0, 2, 1, N_("<device> <name> "), N_("open loop-AES device as mapping <name>") },
{ "loopaesClose",action_remove, 0, 1, 1, N_("<name>"), N_("remove loop-AES mapping") },
{ NULL, NULL, 0, 0, 0, NULL, NULL }
};
@@ -253,6 +256,38 @@ out:
return r;
}
static int action_loopaesOpen(int arg)
{
struct crypt_device *cd = NULL;
struct crypt_params_loopaes params = {
.hash = opt_hash ?: NULL, // FIXME
.offset = opt_offset,
};
unsigned int key_size = (opt_key_size ?: 128) / 8;
int r;
if (!opt_key_file) {
log_err(_("Option --key-file is required.\n"));
return -EINVAL;
}
if ((r = crypt_init(&cd, action_argv[1])))
goto out;
r = crypt_format(cd, CRYPT_LOOPAES, NULL, NULL, NULL, NULL,
key_size, &params);
if (r < 0)
goto out;
r = crypt_activate_by_keyfile(cd, action_argv[0],
CRYPT_ANY_SLOT, opt_key_file, 0,
opt_readonly ? CRYPT_ACTIVATE_READONLY : 0);
out:
crypt_free(cd);
return r;
}
static int action_remove(int arg)
{
struct crypt_device *cd = NULL;
@@ -1027,9 +1062,10 @@ int main(int argc, char **argv)
if (opt_key_size &&
strcmp(aname, "luksFormat") &&
strcmp(aname, "create")) {
strcmp(aname, "create") &&
strcmp(aname, "loopaesOpen")) {
usage(popt_context, EXIT_FAILURE,
_("Option --key-size is allowed only for luksFormat and create.\n"
_("Option --key-size is allowed only for luksFormat, create and loopaesOpen.\n"
"To limit read from keyfile use --keyfile-size=(bytes)."),
poptGetInvocationName(popt_context));
}