diff mbox series

[6/6] dm ima: update dm documentation for ima measurement support

Message ID 20210813213801.297051-7-tusharsu@linux.microsoft.com (mailing list archive)
State New, archived
Headers show
Series updates to device mapper target measurement using ima | expand

Commit Message

Tushar Sugandhi Aug. 13, 2021, 9:38 p.m. UTC
The ima documentation for measuring DM targets (dm-ima.rst) is
missing the attribute information for the targets - 'cache', 'integrity',
'multipath', and 'snapshot'.  It is also missing the grammar for
various DM events and targets, which can help the attestation servers
to determine what data to expect for a given DM device.  Further,
the documentation needs to be updated to incorporate code changes
made to DM ima events and targets as part of this patch series.  For
instance, prefixing the event names with "dm_", adding the DM version to
events, prefixing the table hashes in the ima log with the 
hash algorithm etc.  There are warnings reported by 'make htmldocs' on 
dm-ima.rst, which need to be fixed.  And lastly, the expected behavior
needs to be documented when the configuration CONFIG_IMA_DISABLE_HTABLE
is disabled.

Update the documentation to add examples for 'cache', 'integrity',
'multipath', and 'snapshot' targets.  Add the grammar for
various DM events and targets in Backus Naur form,
so that the attestation servers can interpret and act on the ima 
measurements for DM target.  Fix htmldocs warnings in dm-ima.rst.  Update
the documentation to be consistent with the code changes that are part of
this patch series.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
---
 .../admin-guide/device-mapper/dm-ima.rst      | 827 +++++++++++++-----
 1 file changed, 618 insertions(+), 209 deletions(-)
diff mbox series

Patch

diff --git a/Documentation/admin-guide/device-mapper/dm-ima.rst b/Documentation/admin-guide/device-mapper/dm-ima.rst
index 41894112ff26..a4aa50a828e0 100644
--- a/Documentation/admin-guide/device-mapper/dm-ima.rst
+++ b/Documentation/admin-guide/device-mapper/dm-ima.rst
@@ -26,9 +26,10 @@  fully trusting the system with business-critical data/workload.
 IMA kernel subsystem provides the necessary functionality for
 device mapper to measure the state and configuration of
 various block devices -
-  - BY device mapper itself, from within the kernel,
-  - in a tamper resistant way,
-  - and re-measured - triggered on state/configuration change.
+
+- by device mapper itself, from within the kernel,
+- in a tamper resistant way,
+- and re-measured - triggered on state/configuration change.
 
 Setting the IMA Policy:
 =======================
@@ -36,271 +37,679 @@  For IMA to measure the data on a given system, the IMA policy on the
 system needs to be updated to have following line, and the system needs
 to be restarted for the measurements to take effect.
 
-/etc/ima/ima-policy
- measure func=CRITICAL_DATA label=device-mapper template=ima-buf
+::
+
+ /etc/ima/ima-policy
+    measure func=CRITICAL_DATA label=device-mapper template=ima-buf
 
 The measurements will be reflected in the IMA logs, which are located at:
 
-/sys/kernel/security/integrity/ima/ascii_runtime_measurements
-/sys/kernel/security/integrity/ima/binary_runtime_measurements
+::
+
+ /sys/kernel/security/integrity/ima/ascii_runtime_measurements
+ /sys/kernel/security/integrity/ima/binary_runtime_measurements
 
 Then IMA ASCII measurement log has the following format:
-PCR TEMPLATE_DIGEST TEMPLATE ALG:EVENT_DIGEST EVENT_NAME EVENT_DATA
 
-PCR := Platform Configuration Register, in which the values are registered.
+::
+
+ <PCR> <TEMPLATE_DATA_DIGEST> <TEMPLATE_NAME> <TEMPLATE_DATA>
+
+ PCR := Platform Configuration Register, in which the values are registered.
        This is applicable if TPM chip is in use.
-TEMPLATE_DIGEST := Template digest of the IMA record.
-TEMPLATE := Template that registered the integrity value (e.g. ima-buf).
-ALG:EVENT_DIGEST = Algorithm to compute event digest, followed by digest of event data
-EVENT_NAME := Description of the event (e.g. 'table_load').
-EVENT_DATA := The event data to be measured.
 
-The DM target data measured by IMA subsystem can alternatively
-be queried from userspace by setting DM_IMA_MEASUREMENT_FLAG with
-DM_TABLE_STATUS_CMD.
+ TEMPLATE_DATA_DIGEST := Template data digest of the IMA record.
+ TEMPLATE_NAME := Template name that registered the integrity value (e.g. ima-buf).
+
+ TEMPLATE_DATA := <ALG> ":" <EVENT_DIGEST> <EVENT_NAME> <EVENT_DATA>
+                  It contains data for the specific event to be measured,
+                  in a given template data format.
+
+ ALG := Algorithm to compute event digest
+ EVENT_DIGEST := Digest of the event data
+ EVENT_NAME := Description of the event (e.g. 'dm_table_load').
+ EVENT_DATA := The event data to be measured.
+
+|
+
+| *NOTE #1:*
+| The DM target data measured by IMA subsystem can alternatively
+ be queried from userspace by setting DM_IMA_MEASUREMENT_FLAG with
+ DM_TABLE_STATUS_CMD.
+
+|
+
+| *NOTE #2:*
+| The Kernel configuration CONFIG_IMA_DISABLE_HTABLE allows measurement of duplicate records.
+| To support recording duplicate IMA events in the IMA log, the Kernel needs to be configured with
+ CONFIG_IMA_DISABLE_HTABLE=y.
 
 Supported Device States:
 ========================
-Following device state changes will trigger IMA measurements.
-01. Table load
-02. Device resume
-03. Device remove
-04. Table clear
-05. Device rename
-
-01. Table load:
+Following device state changes will trigger IMA measurements:
+
+ 1. Table load
+ #. Device resume
+ #. Device remove
+ #. Table clear
+ #. Device rename
+
+1. Table load:
 ---------------
 When a new table is loaded in a device's inactive table slot,
 the device information and target specific details from the
 targets in the table are measured.
 
-For instance, if a linear device is created with the following table entries,
-# dmsetup create linear1
-0 2 linear /dev/loop0 512
-2 2 linear /dev/loop0 512
-4 2 linear /dev/loop0 512
-6 2 linear /dev/loop0 512
-
-Then IMA ASCII measurement log will have an entry with:
-EVENT_NAME := table_load
-EVENT_DATA := [device_data];[target_data_row_1];[target_data_row_2];...[target_data_row_n];
-
-E.g.
-(converted from ASCII to text for readability)
-10 a8c5ff755561c7a28146389d1514c318592af49a ima-buf sha256:4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72
-table_load
-name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
-target_index=0,target_begin=0,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-target_index=1,target_begin=2,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-target_index=2,target_begin=4,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-target_index=3,target_begin=6,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-
-02. Device resume:
+The IMA measurement log has the following format for 'dm_table_load':
+
+::
+
+ EVENT_NAME := "dm_table_load"
+ EVENT_DATA := <dm_version_str> ";" <device_metadata> ";" <table_load_data>
+
+ dm_version_str := "dm_version=" <N> "." <N> "." <N>
+                  Same as Device Mapper driver version.
+ device_metadata := <device_name> "," <device_uuid> "," <device_major> "," <device_minor> ","
+                   <minor_count> "," <num_device_targets> ";"
+
+ device_name := "name=" <dm-device-name>
+ device_uuid := "uuid=" <dm-device-uuid>
+ device_major := "major=" <N>
+ device_minor := "minor=" <N>
+ minor_count := "minor_count=" <N>
+ num_device_targets := "num_targets=" <N>
+ dm-device-name := Name of the device. If it contains special characters like '\', ',', ';',
+                   they are prefixed with '\'.
+ dm-device-uuid := UUID of the device. If it contains special characters like '\', ',', ';',
+                   they are prefixed with '\'.
+
+ table_load_data := <target_data>
+                    Represents the data (as name=value pairs) from various targets in the table,
+                    which is being loaded into the DM device's inactive table slot.
+ target_data := <target_data_row> | <target_data><target_data_row>
+
+ target_data_row := <target_index> "," <target_begin> "," <target_len> "," <target_name> ","
+                    <target_version> "," <target_attributes> ";"
+ target_index := "target_index=" <N>
+                 Represents nth target in the table (from 0 to N-1 targets specified in <num_device_targets>)
+                 If all the data for N targets doesn't fit in the given buffer - then the data that fits
+                 in the buffer (say from target 0 to x) is measured in a given IMA event.
+                 The remaining data from targets x+1 to N-1 is measured in the subsequent IMA events,
+                 with the same format as that of 'dm_table_load'
+                 i.e. <dm_version_str> ";" <device_metadata> ";" <table_load_data>.
+
+ target_begin := "target_begin=" <N>
+ target_len := "target_len=" <N>
+ target_name := Name of the target. 'linear', 'crypt', 'integrity' etc.
+                The targets that are supported for IMA measurements are documented below in the
+                'Supported targets' section.
+ target_version := "target_version=" <N> "." <N> "." <N>
+ target_attributes := Data containing comma separated list of name=value pairs of target specific attributes.
+
+ For instance, if a linear device is created with the following table entries,
+  # dmsetup create linear1
+  0 2 linear /dev/loop0 512
+  2 2 linear /dev/loop0 512
+  4 2 linear /dev/loop0 512
+  6 2 linear /dev/loop0 512
+
+ Then IMA ASCII measurement log will have the following entry:
+ (converted from ASCII to text for readability)
+
+ 10 a8c5ff755561c7a28146389d1514c318592af49a ima-buf sha256:4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72
+ dm_table_load
+ dm_version=4.45.0;
+ name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
+ target_index=0,target_begin=0,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
+ target_index=1,target_begin=2,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
+ target_index=2,target_begin=4,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
+ target_index=3,target_begin=6,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
+
+2. Device resume:
 ------------------
-When a suspended device is resumed, the device information and a sha256 hash of the
+When a suspended device is resumed, the device information and the hash of the
 data from previous load of an active table are measured.
 
-For instance, if a linear device is resumed with the following command,
-#dmsetup resume linear1
+The IMA measurement log has the following format for 'dm_device_resume':
 
-Then IMA ASCII measurement log will have an entry with:
-EVENT_NAME := device_resume
-EVENT_DATA := [device_data];active_table_hash=(sha256hash([device_data];[target_data_row_1];...[target_data_row_n]);
-              current_device_capacity=<N>;
+::
 
-E.g.
-(converted from ASCII to text for readability)
-10 56c00cc062ffc24ccd9ac2d67d194af3282b934e ima-buf sha256:e7d12c03b958b4e0e53e7363a06376be88d98a1ac191fdbd3baf5e4b77f329b6
-device_resume
-name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
-active_table_hash=4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72;current_device_capacity=8;
+ EVENT_NAME := "dm_device_resume"
+ EVENT_DATA := <dm_version_str> ";" <device_metadata> ";" <active_table_hash> ";" <current_device_capacity> ";"
 
-03. Device remove:
-------------------
-When a device is removed, the device information and a sha256 hash of the
-data from an active and inactive table are measured.
+ dm_version_str := As described in the 'Table load' section above.
+ device_metadata := As described in the 'Table load' section above.
+ active_table_hash := "active_table_hash=" <table_hash_alg> ":" <table_hash>
+                      Rerpresents the hash of the IMA data being measured for the
+                      active table for the device.
+ table_hash_alg := Algorithm used to compute the hash.
+ table_hash := Hash of the (<dm_version_str> ";" <device_metadata> ";" <table_load_data> ";")
+               as described in the 'dm_table_load' above.
+               Note: If the table_load data spans across multiple IMA 'dm_table_load'
+               events for a given device, the hash is computed combining all the event data
+               i.e. (<dm_version_str> ";" <device_metadata> ";" <table_load_data> ";")
+               across all those events.
+ current_device_capacity := "current_device_capacity=" <N>
 
-For instance, if a linear device is removed with the following command,
-# dmsetup remove linear1
+ For instance, if a linear device is resumed with the following command,
+ #dmsetup resume linear1
 
-Then IMA ASCII measurement log will have an entry with:
-EVENT_NAME := device_remove
-EVENT_DATA := [device_active_metadata];[device_inactive_metadata];
-              [active_table_hash=(sha256hash([device_active_metadata];[active_table_row_1];...[active_table_row_n]),
-              [inactive_table_hash=(sha256hash([device_inactive_metadata];[inactive_table_row_1];...[inactive_table_row_n]),
-              remove_all=[y|n];current_device_capacity=<N>;
+ then IMA ASCII measurement log will have an entry with:
+ (converted from ASCII to text for readability)
 
-E.g
-(converted from ASCII to text for readability)
-10 499812b621b705061c4514d643894483e16d2619 ima-buf sha256:c3f26b02f09bf5b464925589454bdd4d354077ce430fd1e75c9e96ce29cd1cad
-device_remove
-device_active_metadata=name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
-device_inactive_metadata=name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=2;
-active_table_hash=4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72,
-inactive_table_hash=5596cc857b0e887fd0c5d58dc6382513284596b07f09fd37efae2da224bd521d,remove_all=n;
-current_device_capacity=8;
+ 10 56c00cc062ffc24ccd9ac2d67d194af3282b934e ima-buf sha256:e7d12c03b958b4e0e53e7363a06376be88d98a1ac191fdbd3baf5e4b77f329b6
+ dm_device_resume
+ dm_version=4.45.0;
+ name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
+ active_table_hash=sha256:4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72;current_device_capacity=8;
 
+3. Device remove:
+------------------
+When a device is removed, the device information and a sha256 hash of the
+data from an active and inactive table are measured.
 
-04. Table clear:
+The IMA measurement log has the following format for 'dm_device_remove':
+
+::
+
+ EVENT_NAME := "dm_device_remove"
+ EVENT_DATA := <dm_version_str> ";" <device_active_metadata> ";" <device_inactive_metadata> ";"
+               <active_table_hash> "," <inactive_table_hash> "," <remove_all> ";" <current_device_capacity> ";"
+
+ dm_version_str := As described in the 'Table load' section above.
+ device_active_metadata := Device metadata that reflects the currently loaded active table.
+                           The format is same as 'device_metadata' described in the 'Table load' section above.
+ device_inactive_metadata := Device metadata that reflects the inactive table.
+                             The format is same as 'device_metadata' described in the 'Table load' section above.
+ active_table_hash := Hash of the currently loaded active table.
+                      The format is same as 'active_table_hash' described in the 'Device resume' section above.
+ inactive_table_hash :=  Hash of the inactive table.
+                         The format is same as 'active_table_hash' described in the 'Device resume' section above.
+ remove_all := "remove_all=" <yes_no>
+ yes_no := "y" | "n"
+ current_device_capacity := "current_device_capacity=" <N>
+
+ For instance, if a linear device is removed with the following command,
+  #dmsetup remove l1
+
+ then IMA ASCII measurement log will have the following entry:
+ (converted from ASCII to text for readability)
+
+ 10 790e830a3a7a31590824ac0642b3b31c2d0e8b38 ima-buf sha256:ab9f3c959367a8f5d4403d6ce9c3627dadfa8f9f0e7ec7899299782388de3840
+ dm_device_remove
+ dm_version=4.45.0;
+ device_active_metadata=name=l1,uuid=,major=253,minor=2,minor_count=1,num_targets=2;
+ device_inactive_metadata=name=l1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
+ active_table_hash=sha256:4a7e62efaebfc86af755831998b7db6f59b60d23c9534fb16a4455907957953a,
+ inactive_table_hash=sha256:9d79c175bc2302d55a183e8f50ad4bafd60f7692fd6249e5fd213e2464384b86,remove_all=n;
+ current_device_capacity=2048;
+
+4. Table clear:
 ----------------
 When an inactive table is cleared from the device, the device information and a sha256 hash of the
 data from an inactive table are measured.
 
-For instance, if a linear device's inactive table is cleared with the following command,
+The IMA measurement log has the following format for 'dm_table_clear':
+
+::
 
-# dmsetup clear linear1
+ EVENT_NAME := "dm_table_clear"
+ EVENT_DATA := <dm_version_str> ";" <device_inactive_metadata> ";" <inactive_table_hash> ";" <current_device_capacity> ";"
 
-Then IMA ASCII measurement log will have an entry with:
-EVENT_NAME := table_clear
-EVENT_DATA := [device_data];inactive_table_hash=(sha256hash([device_data];[inactive_table_row_1];...[inactive_table_row_n]);
-current_device_capacity=<N>;
+ dm_version_str := As described in the 'Table load' section above.
+ device_inactive_metadata := Device metadata that was captured during the load time inactive table being cleared.
+                             The format is same as 'device_metadata' described in the 'Table load' section above.
+ inactive_table_hash := Hash of the inactive table being cleared from the device.
+                        The format is same as 'active_table_hash' described in the 'Device resume' section above.
+ current_device_capacity := "current_device_capacity=" <N>
 
-E.g.
-(converted from ASCII to text for readability)
-10 9c11e284d792875352d51c09f6643c96649484be ima-buf sha256:84b22b364ea4d8264fa33c38635c18ef448fa9077731fa7e5f969b1da2003ea4
-table_clear
-name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=2;
-inactive_table_hash=5596cc857b0e887fd0c5d58dc6382513284596b07f09fd37efae2da224bd521d;current_device_capacity=0;
+ For instance, if a linear device's inactive table is cleared,
+  #dmsetup clear l1
 
+ then IMA ASCII measurement log will have an entry with:
+ (converted from ASCII to text for readability)
 
-05. Device rename:
+ 10 77d347408f557f68f0041acb0072946bb2367fe5 ima-buf sha256:42f9ca22163fdfa548e6229dece2959bc5ce295c681644240035827ada0e1db5
+ dm_table_clear
+ dm_version=4.45.0;
+ name=l1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
+ inactive_table_hash=sha256:75c0dc347063bf474d28a9907037eba060bfe39d8847fc0646d75e149045d545;current_device_capacity=1024;
+
+5. Device rename:
 ------------------
 When an device's NAME or UUID is changed, the device information and the new NAME and UUID
 are measured.
 
-For instance, if a linear device's name is changed with the following command,
+The IMA measurement log has the following format for 'dm_device_rename':
+
+::
+
+ EVENT_NAME := "dm_device_rename"
+ EVENT_DATA := <dm_version_str> ";" <device_active_metadata> ";" <new_device_name> "," <new_device_uuid> ";" <current_device_capacity> ";"
+
+ dm_version_str := As described in the 'Table load' section above.
+ device_active_metadata := Device metadata that reflects the currently loaded active table.
+                           The format is same as 'device_metadata' described in the 'Table load' section above.
+ new_device_name := "new_name=" <dm-device-name>
+ dm-device-name := Same as <dm-device-name> described in 'Table load' section above
+ new_device_uuid := "new_uuid=" <dm-device-uuid>
+ dm-device-uuid := Same as <dm-device-uuid> described in 'Table load' section above
+ current_device_capacity := "current_device_capacity=" <N>
+
+ E.g 1: if a linear device's name is changed with the following command,
+  #dmsetup rename linear1 --setuuid 1234-5678
 
-#dmsetup rename linear1 linear=2
-Then IMA ASCII measurement log will have an entry with:
-EVENT_NAME := device_rename
-EVENT_DATA := [current_device_data];new_name=<new_name_value>;new_uuid=<new_uuid_value>;current_device_capacity=<N>;
+ then IMA ASCII measurement log will have an entry with:
+ (converted from ASCII to text for readability)
 
-E.g 1:
-#dmsetup rename linear1 --setuuid 1234-5678
+ 10 8b0423209b4c66ac1523f4c9848c9b51ee332f48 ima-buf sha256:6847b7258134189531db593e9230b257c84f04038b5a18fd2e1473860e0569ac
+ dm_device_rename
+ dm_version=4.45.0;
+ name=linear1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;new_name=linear1,new_uuid=1234-5678;
+ current_device_capacity=1024;
 
-IMA Log entry:
-(converted from ASCII to text for readability)
-10 7380ef4d1349fe1ebd74affa54e9fcc960e3cbf5 ima-buf sha256:9759e36a17a967ea43c1bf3455279395a40bd0401105ec5ad8edb9a52054efc7
-device_rename
-name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=1;new_name=linear1,new_uuid=1234-5678;current_device_capacity=2;
+ E.g 2:  if a linear device's name is changed with the following command,
+  # dmsetup rename linear1 linear=2
 
-E.g 2:
-# dmsetup rename linear1 linear=2
-10 092c8266fc36e44f74c59f123ecfe15310f249f4 ima-buf sha256:4cf8b85c81fa6fedaeb602b05019124dbbb0605dce58fcdeea56887a8a3874cd
-device_rename
-name=linear1,uuid=1234-5678,major=253,minor=0,minor_count=1,num_targets=1;new_name=linear\=2,new_uuid=1234-5678;current_device_capacity=2;
+ then IMA ASCII measurement log will have an entry with:
+ (converted from ASCII to text for readability)
 
+ 10 bef70476b99c2bdf7136fae033aa8627da1bf76f ima-buf sha256:8c6f9f53b9ef9dc8f92a2f2cca8910e622543d0f0d37d484870cb16b95111402
+ dm_device_rename
+ dm_version=4.45.0;
+ name=linear1,uuid=1234-5678,major=253,minor=2,minor_count=1,num_targets=1;
+ new_name=linear\=2,new_uuid=1234-5678;
+ current_device_capacity=1024;
 
 Supported targets:
 ==================
-Following targets are supported to measure their data using IMA.
-
-01. cache
-02. crypt
-03. integrity
-04. linear
-05. mirror
-06. multipath
-07. raid
-08. snapshot
-09. striped
-10. verity
 
-01. cache
----------
-<<documenatation in progress>>
+Following targets are supported to measure their data using IMA:
+
+ 1. cache
+ #. crypt
+ #. integrity
+ #. linear
+ #. mirror
+ #. multipath
+ #. raid
+ #. snapshot
+ #. striped
+ #. verity
 
-02. crypt
+1. cache
 ---------
-When a crypt target is loaded, then IMA ASCII measurement log will have an entry
-similar to the following, depicting what crypt attributes are measured in EVENT_DATA.
-
-(converted from ASCII to text for readability)
-10 fe3b80a35b155bd282df778e2625066c05fc068c ima-buf sha256:2d86ce9d6f16a4a97607318aa123ae816e0ceadefeea7903abf7f782f2cb78ad
-table_load
-name=test-crypt,uuid=,major=253,minor=0,minor_count=1,num_targets=1;
-target_index=0,target_begin=0,target_len=1953125,target_name=crypt,target_version=1.23.0,
-allow_discards=y,same_cpu=n,submit_from_crypt_cpus=n,no_read_workqueue=n,no_write_workqueue=n,
-iv_large_sectors=n,cipher_string=aes-xts-plain64,key_size=32,key_parts=1,key_extra_size=0,key_mac_size=0;
-
-03. integrity
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'cache' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <metadata_mode> "," <cache_metadata_device> ","
+                      <cache_device> "," <cache_origin_device> "," <writethrough> "," <writeback> ","
+                      <passthrough> "," <no_discard_passdown> ";"
+
+ target_name := "target_name=cache"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ metadata_mode := "metadata_mode=" <cache_metadata_mode>
+ cache_metadata_mode := "fail" | "ro" | "rw"
+ cache_device := "cache_device=" <cache_device_name_string>
+ cache_origin_device := "cache_origin_device=" <cache_origin_device_string>
+ writethrough := "writethrough=" <yes_no>
+ writeback := "writeback=" <yes_no>
+ passthrough := "passthrough=" <yes_no>
+ no_discard_passdown := "no_discard_passdown=" <yes_no>
+ yes_no := "y" | "n"
+
+ E.g.
+ When a 'cache' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'cache' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;name=cache1,uuid=cache_uuid,major=253,minor=2,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=28672,target_name=cache,target_version=2.2.0,metadata_mode=rw,
+ cache_metadata_device=253:4,cache_device=253:3,cache_origin_device=253:5,writethrough=y,writeback=n,
+ passthrough=n,metadata2=y,no_discard_passdown=n;
+
+
+2. crypt
+---------
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'crypt' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <allow_discards> "," <same_cpu_crypt> ","
+                      <submit_from_crypt_cpus> "," <no_read_workqueue> "," <no_write_workqueue> ","
+                      <iv_large_sectors> "," <iv_large_sectors> "," [<integrity_tag_size> ","] [<cipher_auth> ","]
+                      [<sector_size> ","] [<cipher_string> ","] <key_size> "," <key_parts> ","
+                      <key_extra_size> "," <key_mac_size> ";"
+
+ target_name := "target_name=crypt"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ allow_discards := "allow_discards=" <yes_no>
+ same_cpu_crypt := "same_cpu_crypt=" <yes_no>
+ submit_from_crypt_cpus := "submit_from_crypt_cpus=" <yes_no>
+ no_read_workqueue := "no_read_workqueue=" <yes_no>
+ no_write_workqueue := "no_write_workqueue=" <yes_no>
+ iv_large_sectors := "iv_large_sectors=" <yes_no>
+ integrity_tag_size := "integrity_tag_size=" <N>
+ cipher_auth := "cipher_auth=" <string>
+ sector_size := "sector_size="  <N>
+ cipher_string := "cipher_string="
+ key_size := "key_size="  <N>
+ key_parts := "key_parts="  <N>
+ key_extra_size := "key_extra_size="  <N>
+ key_mac_size := "key_mac_size="  <N>
+ yes_no := "y" | "n"
+
+ E.g.
+ When a 'crypt' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'crypt' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=crypt1,uuid=crypt_uuid1,major=253,minor=0,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=1953125,target_name=crypt,target_version=1.23.0,
+ allow_discards=y,same_cpu=n,submit_from_crypt_cpus=n,no_read_workqueue=n,no_write_workqueue=n,
+ iv_large_sectors=n,cipher_string=aes-xts-plain64,key_size=32,key_parts=1,key_extra_size=0,key_mac_size=0;
+
+3. integrity
 -------------
-<<documenatation in progress>>
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'integrity' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <dev_name> "," <start>
+                      <tag_size> "," <mode> "," [<meta_device> ","] [<block_size> ","] <recalculate> ","
+                      <allow_discards> "," <fix_padding> "," <fix_hmac> "," <legacy_recalculate> ","
+                      <journal_sectors> "," <interleave_sectors> "," <buffer_sectors> ";"
+
+ target_name := "target_name=integrity"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ dev_name := "dev_name=" <device_name_str>
+ start := "start=" <N>
+ tag_size := "tag_size=" <N>
+ mode := "mode=" <integrity_mode_str>
+ integrity_mode_str := "J" | "B" | "D" | "R"
+ meta_device := "meta_device=" <meta_device_str>
+ block_size := "block_size=" <N>
+ recalculate := "recalculate=" <yes_no>
+ allow_discards := "allow_discards=" <yes_no>
+ fix_padding := "fix_padding=" <yes_no>
+ fix_hmac := "fix_hmac=" <yes_no>
+ legacy_recalculate := "legacy_recalculate=" <yes_no>
+ journal_sectors := "journal_sectors=" <N>
+ interleave_sectors := "interleave_sectors=" <N>
+ buffer_sectors := "buffer_sectors=" <N>
+ yes_no := "y" | "n"
+
+ E.g.
+ When a 'integrity' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'integrity' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=integrity1,uuid=,major=253,minor=1,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=7856,target_name=integrity,target_version=1.10.0,
+ dev_name=253:0,start=0,tag_size=32,mode=J,recalculate=n,allow_discards=n,fix_padding=n,
+ fix_hmac=n,legacy_recalculate=n,journal_sectors=88,interleave_sectors=32768,buffer_sectors=128;
+
+
+4. linear
+----------
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'linear' target.
 
+::
 
-04. linear
-----------
-When a linear target is loaded, then IMA ASCII measurement log will have an entry
-similar to the following, depicting what linear attributes are measured in EVENT_DATA.
-
-(converted from ASCII to text for readability)
-10 a8c5ff755561c7a28146389d1514c318592af49a ima-buf sha256:4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72
-table_load
-name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
-target_index=0,target_begin=0,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-target_index=1,target_begin=2,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-target_index=2,target_begin=4,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-target_index=3,target_begin=6,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
-
-05. mirror
-----------
-When a mirror target is loaded, then IMA ASCII measurement log will have an entry
-similar to the following, depicting what mirror attributes are measured in EVENT_DATA.
-
-(converted from ASCII to text for readability)
-10 90ff9113a00c367df823595dc347425ce3bfc50a ima-buf sha256:8da0678ed3bf616533573d9e61e5342f2bd16cb0b3145a08262641a743806c2e
-table_load
-name=test-mirror,uuid=,major=253,minor=4,minor_count=1,num_targets=1;
-target_index=0,target_begin=0,target_len=1953125,target_name=mirror,target_version=1.14.0,
-nr_mirrors=2,mirror_device_0=253:2,mirror_device_0_status=A,mirror_device_1=253:3,mirror_device_1_status=A,
-handle_errors=y,keep_log=n,log_type_status=;
-
-06. multipath
--------------
-<<documenatation in progress>>
+ target_attributes := <target_name> "," <target_version> "," <device_name> <,> <start> ";"
 
-07. raid
---------
-When a raid target is loaded, then IMA ASCII measurement log will have an entry
-similar to the following, depicting what raid attributes are measured in EVENT_DATA.
+ target_name := "target_name=linear"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ device_name := "device_name=" <linear_device_name_str>
+ start := "start=" <N>
 
-(converted from ASCII to text for readability)
-10 76cb30d0cd0fe099966f20f5c82e3a2ac29b21a0 ima-buf sha256:52250f20b27376fcfb348bdfa1e1cf5acfd6646e0f3ad1a72952cffd9f818753
-table_load
-name=test-raid1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
-target_index=0,target_begin=0,target_len=1953125,target_name=raid,target_version=1.15.1,
-raid_type=raid1,raid_disks=2,raid_state=idle,raid_device_0_status=A,raid_device_1_status=A;
+ E.g.
+ When a 'linear' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'linear' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
 
-08. snapshot
-------------
-<<documenatation in progress>>
+ dm_version=4.45.0;
+ name=linear1,uuid=linear_uuid1,major=253,minor=2,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=28672,target_name=linear,target_version=1.4.0,
+ device_name=253:1,start=2048;
 
-09. striped
+5. mirror
+----------
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'mirror' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <nr_mirrors> ","
+                      <mirror_device_data> "," <handle_errors> "," <keep_log> "," <log_type_status> ";"
+
+ target_name := "target_name=mirror"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ nr_mirrors := "nr_mirrors=" <NR>
+ mirror_device_data := <mirror_device_row> | <mirror_device_data><mirror_device_row>
+                       mirror_device_row is repeated <NR> times - for <NR> described in <nr_mirrors>.
+ mirror_device_row := <mirror_device_name> "," <mirror_device_status>
+ mirror_device_name := "mirror_device_" <X> "=" <mirror_device_name_str>
+                       where <X> ranges from 0 to (<NR> -1) - for <NR> described in <nr_mirrors>.
+ mirror_device_status := "mirror_device_" <X> "_status=" <mirror_device_status_char>
+                         where <X> ranges from 0 to (<NR> -1) - for <NR> described in <nr_mirrors>.
+ mirror_device_status_char := "A" | "F" | "D" | "S" | "R" | "U"
+ handle_errors := "handle_errors=" <yes_no>
+ keep_log := "keep_log=" <yes_no>
+ log_type_status := "log_type_status=" <log_type_status_str>
+ yes_no := "y" | "n"
+
+ E.g.
+ When a 'mirror' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'mirror' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=mirror1,uuid=mirror_uuid1,major=253,minor=6,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=2048,target_name=mirror,target_version=1.14.0,nr_mirrors=2,
+    mirror_device_0=253:4,mirror_device_0_status=A,
+    mirror_device_1=253:5,mirror_device_1_status=A,
+ handle_errors=y,keep_log=n,log_type_status=;
+
+6. multipath
+-------------
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'multipath' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <nr_priority_groups>
+                      ["," <pg_state> "," <priority_groups> "," <priority_group_paths>] ";"
+
+ target_name := "target_name=multipath"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ nr_priority_groups := "nr_priority_groups=" <NPG>
+ priority_groups := <priority_groups_row>|<priority_groups_row><priority_groups>
+ priority_groups_row := "pg_state_" <X> "=" <pg_state_str> "," "nr_pgpaths_" <X>  "=" <NPGP> ","
+                        "path_selector_name_" <X> "=" <string> "," <priority_group_paths>
+                        where <X> ranges from 0 to (<NPG> -1) - for <NPG> described in <nr_priority_groups>.
+ pg_state_str := "E" | "A" | "D"
+ <priority_group_paths> := <priority_group_paths_row> | <priority_group_paths_row><priority_group_paths>
+ priority_group_paths_row := "path_name_" <X> "_" <Y> "=" <string> "," "is_active_" <X> "_" <Y> "=" <is_active_str>
+                             "fail_count_" <X> "_" <Y> "=" <N> "," "path_selector_status_" <X> "_" <Y> "=" <path_selector_status_str>
+                             where <X> ranges from 0 to (<NPG> -1) - for <NPG> described in <nr_priority_groups>,
+                             and <Y> ranges from 0 to (<NPGP> -1) - for <NPGP> described in <priority_groups_row>.
+ is_active_str := "A" | "F"
+
+ E.g.
+ When a 'multipath' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'multipath' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=mp,uuid=,major=253,minor=0,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=2097152,target_name=multipath,target_version=1.14.0,nr_priority_groups=2,
+    pg_state_0=E,nr_pgpaths_0=2,path_selector_name_0=queue-length,
+        path_name_0_0=8:16,is_active_0_0=A,fail_count_0_0=0,path_selector_status_0_0=,
+        path_name_0_1=8:32,is_active_0_1=A,fail_count_0_1=0,path_selector_status_0_1=,
+    pg_state_1=E,nr_pgpaths_1=2,path_selector_name_1=queue-length,
+        path_name_1_0=8:48,is_active_1_0=A,fail_count_1_0=0,path_selector_status_1_0=,
+        path_name_1_1=8:64,is_active_1_1=A,fail_count_1_1=0,path_selector_status_1_1=;
+
+7. raid
+--------
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'raid' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <raid_type> "," <raid_disks> "," <raid_state>
+                      <raid_device_status> ["," journal_dev_mode] ";"
+
+ target_name := "target_name=raid"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ raid_type := "raid_type=" <raid_type_str>
+ raid_disks := "raid_disks=" <NRD>
+ raid_state := "raid_state=" <raid_state_str>
+ raid_state_str := "frozen" | "reshape" |"resync" | "check" | "repair" | "recover" | "idle" |"undef"
+ raid_device_status := <raid_device_status_row> | <raid_device_status_row><raid_device_status>
+                       <raid_device_status_row> is repeated <NRD> times - for <NRD> described in <raid_disks>.
+ raid_device_status_row := "raid_device_" <X> "_status=" <raid_device_status_str>
+                           where <X> ranges from 0 to (<NRD> -1) - for <NRD> described in <raid_disks>.
+ raid_device_status_str := "A" | "D" | "a" | "-"
+ journal_dev_mode := "journal_dev_mode=" <journal_dev_mode_str>
+ journal_dev_mode_str := "writethrough" | "writeback" | "invalid"
+
+ E.g.
+ When a 'raid' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'raid' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=raid_LV1,uuid=uuid_raid_LV1,major=253,minor=12,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=2048,target_name=raid,target_version=1.15.1,
+ raid_type=raid10,raid_disks=4,raid_state=idle,
+    raid_device_0_status=A,
+    raid_device_1_status=A,
+    raid_device_2_status=A,
+    raid_device_3_status=A;
+
+
+8. snapshot
+------------
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'snapshot' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <snap_origin_name> ","
+                      <snap_cow_name> "," <snap_valid> "," <snap_merge_failed> "," <snapshot_overflowed> ";"
+
+ target_name := "target_name=snapshot"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ snap_origin_name := "snap_origin_name=" <string>
+ snap_cow_name := "snap_cow_name=" <string>
+ snap_valid := "snap_valid=" <yes_no>
+ snap_merge_failed := "snap_merge_failed=" <yes_no>
+ snapshot_overflowed := "snapshot_overflowed=" <yes_no>
+ yes_no := "y" | "n"
+
+ E.g.
+ When a 'snapshot' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'snapshot' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=snap1,uuid=snap_uuid1,major=253,minor=13,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=4096,target_name=snapshot,target_version=1.16.0,
+ snap_origin_name=253:11,snap_cow_name=253:12,snap_valid=y,snap_merge_failed=n,snapshot_overflowed=n;
+
+9. striped
 -----------
-When a linear target is loaded, then IMA ASCII measurement log will have an entry
-similar to the following, depicting what linear attributes are measured in EVENT_DATA.
-
-(converted from ASCII to text for readability)
-10 7bd94fa8f799169b9f12d97b9dbdce4dc5509233 ima-buf sha256:0d148eda69887f7833f1a6042767b54359cd23b64fa941b9e1856879eee1f778
-table_load
-name=test-raid0,uuid=,major=253,minor=8,minor_count=1,num_targets=1;
-target_index=0,target_begin=0,target_len=7812096,target_name=striped,target_version=1.6.0,stripes=4,chunk_size=128,
-stripe_0_device_name=253:1,stripe_0_physical_start=0,stripe_0_status=A,
-stripe_1_device_name=253:3,stripe_1_physical_start=0,stripe_1_status=A,
-stripe_2_device_name=253:5,stripe_2_physical_start=0,stripe_2_status=A,
-stripe_3_device_name=253:7,stripe_3_physical_start=0,stripe_3_status=A;
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'striped' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <stripes> "," <chunk_size> ","
+                      <stripe_data> ";"
+
+ target_name := "target_name=striped"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ stripes := "stripes=" <NS>
+ chunk_size := "chunk_size=" <N>
+ stripe_data := <stripe_data_row>|<stripe_data><stripe_data_row>
+ stripe_data_row := <stripe_device_name> "," <stripe_physical_start> "," <stripe_status>
+ stripe_device_name := "stripe_" <X> "_device_name=" <stripe_device_name_str>
+                       where <X> ranges from 0 to (<NS> -1) - for <NS> described in <stripes>.
+ stripe_physical_start := "stripe_" <X> "_physical_start=" <N>
+                           where <X> ranges from 0 to (<NS> -1) - for <NS> described in <stripes>.
+ stripe_status := "stripe_" <X> "_status=" <stripe_status_str>
+                  where <X> ranges from 0 to (<NS> -1) - for <NS> described in <stripes>.
+ stripe_status_str := "D" | "A"
+
+ E.g.
+ When a 'striped' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'striped' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=striped1,uuid=striped_uuid1,major=253,minor=5,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=640,target_name=striped,target_version=1.6.0,stripes=2,chunk_size=64,
+    stripe_0_device_name=253:0,stripe_0_physical_start=2048,stripe_0_status=A,
+    stripe_1_device_name=253:3,stripe_1_physical_start=2048,stripe_1_status=A;
 
 10. verity
 ----------
-When a verity target is loaded, then IMA ASCII measurement log will have an entry
-similar to the following, depicting what verity attributes are measured in EVENT_DATA.
-
-(converted from ASCII to text for readability)
-10 fced5f575b140fc0efac302c88a635174cd663da ima-buf sha256:021370c1cc93929460b06922c606334fb1d7ea5ecf04f2384f3157a446894283
-table_load
-name=test-verity,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
-target_index=0,target_begin=0,target_len=1953120,target_name=verity,target_version=1.8.0,hash_failed=V,
-verity_version=1,data_device_name=253:1,hash_device_name=253:0,verity_algorithm=sha256,
-root_digest=29cb87e60ce7b12b443ba6008266f3e41e93e403d7f298f8e3f316b29ff89c5e,
-salt=e48da609055204e89ae53b655ca2216dd983cf3cb829f34f63a297d106d53e2d,
-ignore_zero_blocks=n,check_at_most_once=n;
+The 'target_attributes' (described as part of EVENT_DATA in 'Table load'
+section above) has the following data format for 'verity' target.
+
+::
+
+ target_attributes := <target_name> "," <target_version> "," <hash_failed> "," <verity_version> ","
+                      <data_device_name> "," <hash_device_name> "," <verity_algorithm> "," <root_digest> ","
+                      <salt> "," <ignore_zero_blocks> "," <check_at_most_once> ["," <root_hash_sig_key_desc>]
+                      ["," <verity_mode>] ";"
+
+ target_name := "target_name=verity"
+ target_version := "target_version=" <N> "." <N> "." <N>
+ hash_failed := "hash_failed=" <hash_failed_str>
+ hash_failed_str := "C" | "V"
+ verity_version := "verity_version=" <verity_version_str>
+ data_device_name := "data_device_name=" <data_device_name_str>
+ hash_device_name := "hash_device_name=" <hash_device_name_str>
+ verity_algorithm := "verity_algorithm=" <verity_algorithm_str>
+ root_digest := "root_digest=" <root_digest_str>
+ salt := "salt=" <salt_str>
+ salt_str := "-" <verity_salt_str>
+ ignore_zero_blocks := "ignore_zero_blocks=" <yes_no>
+ check_at_most_once := "check_at_most_once=" <yes_no>
+ root_hash_sig_key_desc := "root_hash_sig_key_desc="
+ verity_mode := "verity_mode=" <verity_mode_str>
+ verity_mode_str := "ignore_corruption" | "restart_on_corruption" | "panic_on_corruption" | "invalid"
+ yes_no := "y" | "n"
+
+ E.g.
+ When a 'verity' target is loaded, then IMA ASCII measurement log will have an entry
+ similar to the following, depicting what 'verity' attributes are measured in EVENT_DATA
+ for 'dm_table_load' event.
+ (converted from ASCII to text for readability)
+
+ dm_version=4.45.0;
+ name=test-verity,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
+ target_index=0,target_begin=0,target_len=1953120,target_name=verity,target_version=1.8.0,hash_failed=V,
+ verity_version=1,data_device_name=253:1,hash_device_name=253:0,verity_algorithm=sha256,
+ root_digest=29cb87e60ce7b12b443ba6008266f3e41e93e403d7f298f8e3f316b29ff89c5e,
+ salt=e48da609055204e89ae53b655ca2216dd983cf3cb829f34f63a297d106d53e2d,
+ ignore_zero_blocks=n,check_at_most_once=n;