Also support --skip option for loopaesOpen.

git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@481 36d66b0a-2a48-0410-832c-cd162a569da5

ChangeLog

@@ -1,3 +1,6 @@
+2011-04-22  Milan Broz  <mbroz@redhat.com>
+	* Also support --skip option for loopaesOpen.
+
 2011-04-18  Milan Broz  <mbroz@redhat.com>
 	* Respect maximum keyfile size paramater.
 	* Introduce maximum default keyfile size, add configure option.

lib/libcryptsetup.h

@@ -171,6 +171,7 @@ struct crypt_params_luks1 {
 struct crypt_params_loopaes {
 	const char *hash; /* key hash function */
 	uint64_t offset;  /* offset in sectors */
+	uint64_t skip;    /* IV initilisation sector */
 };
 /**
  * Create (format) new crypt device (and possible header on-disk) but not activates it.

lib/loopaes/loopaes.c

@@ -178,9 +178,12 @@ int LOOPAES_activate(struct crypt_device *cd,
 		     const char *base_cipher,
 		     unsigned int keys_count,
 		     struct volume_key *vk,
+		     const char *hash,
+		     uint64_t offset,
+		     uint64_t skip,
 		     uint32_t flags)
 {
-	uint64_t size, offset;
+	uint64_t size;
 	uint32_t req_flags;
 	char *cipher;
 	const char *device;
@@ -188,7 +191,6 @@ int LOOPAES_activate(struct crypt_device *cd,
 
 	size = 0;
 	/* Initial IV (skip) is always the same as offset */
-	offset = crypt_get_data_offset(cd);
 	device = crypt_get_device_name(cd);
 	read_only = flags & CRYPT_ACTIVATE_READONLY;
 
@@ -210,7 +212,7 @@ int LOOPAES_activate(struct crypt_device *cd,
 	r = dm_create_device(name, device,
 			     cipher, CRYPT_LOOPAES,
 			     crypt_get_uuid(cd),
-			     size, offset, offset, vk->keylength, vk->key,
+			     size, skip, offset, vk->keylength, vk->key,
 			     read_only, 0);
 
 	if (!r && !(dm_flags() & req_flags)) {

lib/loopaes/loopaes.h

@@ -17,5 +17,8 @@ int LOOPAES_activate(struct crypt_device *cd,
 		     const char *base_cipher,
 		     unsigned int keys_count,
 		     struct volume_key *vk,
+		     const char *hash,
+		     uint64_t offset,
+		     uint64_t skip,
 		     uint32_t flags);
 #endif

lib/setup.c

@@ -1309,6 +1309,7 @@ static int _crypt_format_loopaes(struct crypt_device *cd,
 		cd->loopaes_hdr.hash = strdup(params->hash);
 
 	cd->loopaes_hdr.offset = params ? params->offset : 0;
+	cd->loopaes_hdr.skip = params ? params->skip : 0;
 
 	return 0;
 }
@@ -2026,7 +2027,10 @@ int crypt_activate_by_keyfile(struct crypt_device *cd,
 			goto out;
 		if (name)
 			r = LOOPAES_activate(cd, name, cd->loopaes_cipher,
-					     key_count, vk, flags);
+					     key_count, vk, NULL,
+					     cd->loopaes_hdr.offset,
+					     cd->loopaes_hdr.skip,
+					     flags);
 	} else
 		r = -EINVAL;
 

man/cryptsetup.8

@@ -179,7 +179,11 @@ parameters are visible in \fB\-\-help\fR output.
 Use \fB\-\-offset\fR to specify device offset. Note the units need to be
 specified in 512 bytes sectors.
 
-\fB<options>\fR can be [\-\-key-file, \-\-key-size, \-\-offset, \-\-readonly].
+Use \fB\-\-skip\fR to specify IV offset. If original device used offset
+and not used it in IV sector calculations, you have to explicitly use
+\fB\-\-skip 0\fR in addition to offset parameter.
+
+\fB<options>\fR can be [\-\-key-file, \-\-key-size, \-\-offset, \-\-skip, \-\-readonly].
 .PP
 \fIloopaesClose\fR <name>
 .IP

src/cryptsetup.c

@@ -50,6 +50,7 @@ static int opt_key_slot = CRYPT_ANY_SLOT;
 static uint64_t opt_size = 0;
 static uint64_t opt_offset = 0;
 static uint64_t opt_skip = 0;
+static int opt_skip_valid = 0;
 static int opt_readonly = 0;
 static int opt_iteration_time = 1000;
 static int opt_batch_mode = 0;
@@ -290,6 +291,7 @@ static int action_loopaesOpen(int arg)
 	struct crypt_params_loopaes params = {
 		.hash = opt_hash ?: NULL, // FIXME
 		.offset = opt_offset,
+		.skip = opt_skip_valid ? opt_skip : opt_offset,
 	};
 	unsigned int key_size = (opt_key_size ?: DEFAULT_LOOPAES_KEYBITS) / 8;
 	int r;
@@ -1157,6 +1159,7 @@ int main(int argc, char **argv)
 				break;
 			case 3:
 				opt_skip = ull_value;
+				opt_skip_valid = 1;
 				break;
 		}
 
@@ -1249,9 +1252,9 @@ int main(int argc, char **argv)
 		usage(popt_context, EXIT_FAILURE, _("Option --uuid is allowed only for luksFormat and luksUUID."),
 		      poptGetInvocationName(popt_context));
 
-	if (opt_skip && strcmp(aname, "create"))
+	if (opt_skip && strcmp(aname, "create") && strcmp(aname, "loopaesOpen"))
 		usage(popt_context, EXIT_FAILURE,
-		_("Option --skip is supported only for create command.\n"),
+		_("Option --skip is supported only for create and loopaesOpen commands.\n"),
 		poptGetInvocationName(popt_context));
 
 	if (opt_offset && strcmp(aname, "create") && strcmp(aname, "loopaesOpen"))

tests/loopaes-test

@@ -60,16 +60,26 @@ function check_exists()
 	[ -b /dev/mapper/$DEV_NAME ] || fail
 }
 
+function get_offset_params() # $offset
+{
+	offset=$1
+	if [ "${offset:0:1}" = "@" ] ; then
+		echo "-o $((${offset:1} / 512)) -p 0"
+	else
+		echo "-o $((offset / 512))"
+	fi
+}
+
 function get_expsum() # $offset
 {
 	case $1 in
 	0)
 	   echo "31e00e0e4c233c89051cd748122fde2c98db0121ca09ba93a3820817ea037bc5"
 	   ;;
-	8192)
+	@8192 | 8192)
 	   echo "bfd94392d1dd8f5d477251d21b3c736e177a4945cd4937847fc7bace82996aed"
 	   ;;
-	8388608)
+	@8388608 | 8388608)
 	   echo "33838fe36928a929bd7971bed7e82bd426c88193fcd692c2e6f1b9c9bfecd4d6"
 	   ;;
 	*) fail
@@ -84,8 +94,8 @@ function check_sum() # $key $keysize $offset
 	sync
 	dmremove $DEV_NAME
 
-	EXPSUM=$(get_expsum $offset)
+	EXPSUM=$(get_expsum $3)
-	$CRYPTSETUP loopaesOpen $LOOPDEV $DEV_NAME -s $2 --key-file $1 -o $3 >/dev/null 2>&1
+	$CRYPTSETUP loopaesOpen $LOOPDEV $DEV_NAME -s $2 --key-file $1 $(get_offset_params $offset) >/dev/null 2>&1
 	ret=$?
 	VSUM=$(sha256sum /dev/mapper/$DEV_NAME | cut -d' ' -f 1)
 	if [ $ret -eq 0 -a "$VSUM" = "$EXPSUM" ] ; then
@@ -136,16 +146,15 @@ check_version || skip "Probably old kernel, test skipped."
 # loop-AES tests
 KEY_SIZES="128 256"
 KEY_FILES="$KEYv1 $KEYv2 $KEYv3"
-DEV_OFFSET="0 8192 8388608"
+DEV_OFFSET="0 8192 @8192 8388608 @8388608"
 
 for key_size in $KEY_SIZES ; do
     for key in $KEY_FILES ; do
         for offset in $DEV_OFFSET ; do
-		offset_sec=$(($offset / 512))
 		prepare "Open loop-AES $key / AES-$key_size / offset $offset"
-		$CRYPTSETUP loopaesOpen $LOOPDEV $DEV_NAME -s $key_size --key-file $key -o $offset_sec || fail
+		$CRYPTSETUP loopaesOpen $LOOPDEV $DEV_NAME -s $key_size --key-file $key $(get_offset_params $offset) || fail
 		check_exists
-		check_sum $key $key_size $offset_sec
+		check_sum $key $key_size $offset
 		$CRYPTSETUP loopaesClose $DEV_NAME || fail
 		check_sum_losetup $key AES$key_size $offset
         done