Revision as of 10:24, 20 November 2017

This page outlines version 7.2 of the TSK database schema. It is used in Autopsy 4.6.0 and beyond. The database is made by using the tsk_loaddb command line tool or the equivalent library-level methods.

The major addition in this release was the addition of communications and account related tables.

Some general notes on this schema:

• Every type of data is assigned a unique ID, called the Object ID
• Data sources are grouped by devices (to allow a computer or phone to have multiple drives in it)
• Data in a disk image has a hierarchy. Images are the root, with volume or file systems below it, followed by volumes and files.
• The tsk_objects table is used to keep track of what object IDs have been used and to map the parent and child relationship.
• This schema has been designed to store more than what TSK initially imports. It has been designed to support carved files and a folder full of local files, etc.
• This schema supports the blackboard so that modules in Autopsy can communicate and save results.
• Virtual files are made of unallocated space with the naming format of:
  • Unalloc_[PARENT-OBJECT-ID]_[BYTE-START]_[BYTE-END]

NOTE: This maybe a bit out of date. The code is the best reference. See the initialize() method in db_sqlite.cpp.

General Information Tables

tsk_db_info

Metadata about the database.

• schema_ver - Version of the database schema used to create database
• tsk_ver - Version of TSK used to create database
• "schema_minor_Ver" - Minor release version of the schema to allow for backward compatible changes.

Object Tables

tsk_objects

Every object (image, volume system, file, etc.) has an entry in this table. This table allows you to find the parent of a given object.

• obj_id - Unique id
• par_obj_id - The object id of the parent object (null for root objects). The parent of a volume system is an image, the parent of a directory is a directory or filesystem, the parent of a filesystem is a volume or an image, etc.
• type - Object type (as TSK_DB_OBJECT_TYPE_ENUM enum).

Data Source/Device Tables

data_source_info

Contains information about a data source, which could be an image. This is where we group data sources into devices (based on device ID)

• obj_id - Id of image/data source in tsk_objects
• device_id - Unique ID (GUID) for the device that contains the data source.
• time_zone - Timezone that the data source was originally located in.

tsk_image_info

Contains information about each set of images that is stored in the database.

• obj_id - Id of image in tsk_objects
• type - Type of disk image format (as TSK_IMG_TYPE_ENUM)
• ssize - Sector size of device in bytes
• tzone - Timezone where image is from (the same format that TSK tools want as input)
• size - Size of the original image (in bytes)
• md5 - Hash of the image. Currently, this is populated only if the input image is E01.
• display_name - display name of the image.

tsk_image_names

Stores path(s) to file(s) on disk that make up an image set.

• obj_id - Id of image in tsk_objects
• name - Path to location of image file on disk
• sequence - Position in sequence of image parts

Volume System Tables

tsk_vs_info

Contains one row for every volume system found in the images.

• obj_id - Id of volume system in tsk_objects
• vs_type - Type of volume system / media management (as TSK_VS_TYPE_ENUM)
• img_offset - Byte offset where VS starts in disk image
• block_size - Size of blocks in bytes

tsk_vs_parts

Contains one row for every volume / partition in the images.

• obj_id - Id of volume in tsk_objects
• addr - Address of this partition
• start - Sector offset of start of partition
• length - Number of sectors in partition
• desc - Description of partition (volume system type-specific)
• flags - Flags for partition (as TSK_VS_PART_FLAG_ENUM)

File System Tables

tsk_fs_info

Contains one for for every file system in the images.

• obj_id - Id of filesystem in tsk_objects
• img_offset - Byte offset that filesystem starts at
• fs_type - Type of file system (as TSK_FS_TYPE_ENUM)
• block_size - Size of each block (in bytes)
• block_count - Number of blocks in filesystem
• root_inum - Metadata address of root directory
• first_inum - First valid metadata address
• last_inum - Last valid metadata address
• display_name - Display name of file system (could be volume label) (New in V3)

tsk_files

Contains one for for every file found in the images. Has the basic metadata for the file.

• obj_id - Id of file in tsk_objects
• fs_obj_id - Id of filesystem in tsk_objects (NULL if file is not located in a file system -- carved in unpartitioned space, etc.)
• type - Type of file: filesystem, carved, etc. (as TSK_DB_FILES_TYPE_ENUM enum)
• attr_type - Type of attribute (as TSK_FS_ATTR_TYPE_ENUM)
• attr_id - Id of attribute
• name - Name of attribute. Will be NULL if attribute doesn't have a name. Must not have any slashes in it.
• meta_addr - Address of the metadata structure that the name points to.
• meta_seq - Sequence of the metadata address - New in V3
• has_layout - True if file has an entry in tsk_file_layout
• has_path - True if file has an entry in tsk_files_path
• dir_type - File type information: directory, file, etc. (as TSK_FS_NAME_TYPE_ENUM)
• meta_type - File type (as TSK_FS_META_TYPE_ENUM)
• dir_flags - Flags that describe allocation status etc. (as TSK_FS_NAME_FLAG_ENUM)
• meta_flags - Flags for this file for its allocation status etc. (as TSK_FS_META_FLAG_ENUM)
• size - File size in bytes
• ctime - Last file / metadata status change time (stored in number of seconds since Jan 1, 1970 UTC)
• crtime - Created time
• atime - Last file content accessed time
• mtime - Last file content modification time
• mode - Unix-style permissions (as TSK_FS_META_MODE_ENUM)
• uid - Owner id
• gid - Group id
• md5 - MD5 hash of file contents
• known - Known status of file (as TSK_DB_FILES_KNOWN_ENUM)
• parent_path - full path of parent folder. Must begin and end with a '/' (Note that a single '/' is valid).
• mime_type - MIME type of the file content, if it has been detected.

tsk_file_layout

Stores the layout of a file within the image. A file will have one or more rows in this table depending on how fragmented it was. All file types use this table (file system, carved, unallocated blocks, etc.).

• obj_id - Id of file in tsk_objects
• sequence - Position of this run in the file (0-based and the obj_id and sequence pair will be unique in the table)
• byte_start - Byte offset of fragment relative to the start of the image file
• byte_len - Length of fragment in bytes

tsk_files_path

If a "locally-stored" file has been imported into the database for analysis, then this table stores its path. Used for derived files and other files that are not directly in the image file.

• obj_id - Id of file in tsk_objects
• path - Path to where the file is locally stored in a file system.
• encoding_type - Method used to store the file on the disk.

file_encoding_types

Methods that can be used to store files on local disks to prevent them from being quarantined by antivirus

• encoding_type - ID of method used to store data. See EncodingType enum.
• name - Display name of technique.

tsk_files_derived_method

Derived files are those that result from analyzing another file. For example, files that are extracted from a ZIP file will be considered derived. This table keeps track of the derivation techniques that were used to make the derived files.

• derived_id - Unique id for this derivation method.
• tool_name - Name of derivation method/tool
• tool_version - Version of tool used in derivation method
• other - Other details

tsk_files_derived

Each derived file has a row that captures the information needed to re-derive it

• obj_id - Id of file in tsk_objects
• derived_id - Id of derivation method in tsk_files_derived_method
• rederive - Details needed to re-derive file (will be specific to the derivation method)

Blackboard Tables

The blackboard is used to store results from analysis modules.

blackboard_artifacts

Stores artifacts associated with objects.

• artifact_id - Id of the artifact (assigned by the database)
• obj_id - Id of the associated object
• artifact_type_id - Id for the type of artifact (can be looked up in the blackboard_artifact_types table)

blackboard_attributes

Stores name value pairs associated with an artifact. Only one of the value columns should be populated

• artifact_id - Id of the associated artifact.
• source - Source string, should be module name that created the entry.
• context - Additional context string
• attribute_type_id - Id for the type of attribute (can be looked up in the blackboard_attribute_types)
• value_type - The type of value (0 for string, 1 for int, 2 for long, 3 for double, 4 for byte array)
• value_byte - A blob of binary data (should be empty unless the value type is byte)
• value_text - A string of text (should be empty unless the value type is string)
• value_int32 - An integer (should be 0 unless the value type is int)
• value_int64 - A long integer (should be 0 unless the value type is long)
• value_double - A double (should be 0.0 unless the value type is double)

blackboard_artifact_types

Types of artifacts

• artifact_type_id - Id for the type (this is used by the blackboard_artifacts table)
• type_name - A string identifier for the type (unique)
• display_name - A display name for the type (not unique, should be human readable)

Types of attribute

blackboard_attribute_types

• attribute_type_id - Id for the type (this is used by the blackboard_attributes table)
• type_name - A string identifier for the type (unique)
• display_name - A display name for the type (not unique, should be human readable)

Tags

tag_names table

Defines what tag names the user has created and can therefore be applied.

• tag_name_id - Unique ID for each tag name
• display_name - Display name of tag
• description - Description (can be empty string)
• color - Color choice for tag (can be empty string)

content_tags table

One row for each file tagged.

• tag_id - unique ID
• obj_id - object id of Content that has been tagged
• tag_name_id - Tag name that was used
• comment - optional comment
• begin_byte_offset - optional byte offset into file that was tagged
• end_byte_offset - optional byte ending offset into file that was tagged

blackboard_artifact_tags table

One row for each artifact that is tagged.

• tag_id - unique ID
• artifact_id - Artifact ID of artifact that was tagged
• tag_name_id - Tag name that was used
• comment - optional comment

Communications / Accounts

These tables keep track of which accounts were found and who communicated with who.

Currently in DRAFT form (Nov 20, 2017)

accounts

A row is created in this table for each unique account in the _case_. Each account has a type and identifier (as assigned by the account provider). For example, EMAIL is an account type and the unique identifier is jdoe@gmail.com.

• account_id - Assigned by the database
• account_type_id - Type of account
• account_unique_identifier - Unique identifier assigned by the provider.
• UNIQUE: account_typeId, account_unique_identifier

account_types

A row is created in this table for each type of Account. Module writers in the future will be able to make their own types (no create API exists as of Nov 2017). Some types are predefined: http://sleuthkit.org/sleuthkit/docs/jni-docs/4.4.1/enumorg_1_1sleuthkit_1_1datamodel_1_1_account_1_1_type.html. (Need to update link to future version)

• account_type_id - Assigned by the database
• type_name - Short, enum name for the type
• display_name - Display name (spaces, etc.)

account_to_instances_map

A row is created for each instance of an account in an artifact (or a file if an artifact was not created).

• account_id - Foreign key reference to the accounts table.
• account_instance_id- Id of where the account was "found"
• UNIQUE: account_id, account_instance_id

relationships

A row is created each time there is a relationship between two accounts. For emails with several recipients, a relationship is added between all recipients and sender. For example, a message from A to B and C would have A<->B, A<->B, B<->C. This is a non-directional relationship. NOTE: Even though this relationship is between Accounts, it is assumed that an "Account Instance" (i.e. an entry in account_to_instances_map) was created for the instance that was mentioned in this relationship.

• relationship_id - Assigned by database
• account1_id - Foreign key to accounts table of one account in relationship
• account2_id -Foreign key to accounts table of other account in relationship
• relationship_source_obj_id - Object ID of file or artifact where relationship was found
• date_time - Date associated with relationship (Unix epoch)
• relationship_type -
• data_source_obj_id -
• UNIQUE: account1_id, account2_id, relationship_source_obj_id

Ingest Module Status

These tables keep track in Autopsy which modules were run on the data sources.

ingest_module_types table

Defines the types of ingest modules supported.

• type_id INTEGER PRIMARY KEY
• type_name TEXT NOT NULL)",

ingest_modules

Defines which modules were installed. One row for each module.

• ingest_module_id INTEGER PRIMARY KEY
• display_name TEXT NOT NULL
• unique_name TEXT UNIQUE NOT NULL
• type_id INTEGER NOT NULL
• version TEXT NOT NULL,

ingest_job_status_types table

• type_id INTEGER PRIMARY KEY
• type_name TEXT NOT NULL

ingest_jobs

One row is created each time ingest is started, which is a set of modules in a pipeline.

• ingest_job_id INTEGER PRIMARY KEY
• obj_id INTEGER NOT NULL
• host_name TEXT NOT NULL
• start_date_time INTEGER NOT NULL
• end_date_time INTEGER NOT NULL
• status_id INTEGER NOT NULL
• settings_dir TEXT

ingest_job_modules

Defines the order of the modules in a given pipeline (i.e. ingest_job)

• ingest_job_id INTEGER
• ingest_module_id INTEGER
• pipeline_position INTEGER,

Indexes

parObjId

Index to speed up the process of finding parent objects.

• artifactID ON blackboard_artifacts(artifact_id)
• artifact_objID ON blackboard_artifacts(obj_id)
• attrsArtifactID ON blackboard_attributes(artifact_id)
• layout_objID ON tsk_file_layout(obj_id)