WARP¶
Binary Ninja ships a first party plugin for WARP a format for transferring analysis information, such as function names and types. This integration is responsible for matching unique functions in a binary and automatically applying information to the analysis. As well as providing the user the ability to select from a set of possible functions, when identifying the unique function fails.
The bundled plugin is open source and is located here.
How WARP Works¶
WARP works by making a function GUID based off the byte contents of the function. Because WARP creates this GUID based off the byte contents, the functions are expected to be an exact match, aside from variant instructions. To use WARP, you only need to know that the function GUID's must match across binaries for the function information to be considered.
To read more about how WARP works, please see the GitHub repository here.
Applied Function Information¶
When a function matches, we will apply the following information:
- Symbol
- Name
- Demangled type
- User defined type
- Calling convention
- Parameter names
- Parameter types
- Return type
- User defined variables
- Name
- Type
- Comments
Loading WARP Files¶
Automatically on start¶
Files are automatically loaded from two locations when Binary Ninja starts:
- Install Directory +
/signatures/
- Can be disabled using the setting
analysis.warp.loadBundledFiles
.
- Can be disabled using the setting
- User Directory +
/signatures/
- Can be disabled using the setting
analysis.warp.loadUserFiles
.
- Can be disabled using the setting
Warning
Always place your signature libraries in your user directory. The installation path is wiped whenever Binary Ninja auto-updates. You can locate it with Open Plugin Folder
in the command palette and navigate "up" a directory.
Manually¶
Aside from using the signature directory you can load any WARP file manually using the
command WARP\\Load File
or via the UI sidebar, they both do the same thing. Once the file is
loaded, you do not need to load if for every view, it is available globally.
Tip
When loading signatures you may encounter a dialog asking to "Override file target?" this happens when your file has a different platform, which is common if you are working with firmware where the intermediate libraries may be detected as a different target, this is OK you can continue loading, and it will change the file target to fit the view.
Creating WARP Files¶
Before you actually can create these WARP files, you must identify the binary files relevant to the target binary. Once that is done, you can determine which of the following procedures is best:
You can create signatures for the current view by running the
command WARP\\Create\\From View
or by hitting the associated
button in the WARP sidebar.
Using the command WARP\\Create\\From File(s)
you can create
a signature file for an external file. This is useful if you
are generating signatures for library files (.a
, .lib
, .rlib
).
Tip
You can also create signature files using the provided API, see the API section for more details.
Both the file and project signature creation support loading the following file formats:
- Binary files (
.exe
,.so
,.dylib
) - WARP files (
.warp
)- Useful when merging multiple warp files in a project.
- BNDB files (
.bndb
)- Using a database will allow you to mark up the function information and also cut down on processing time as the required information has already been created prior to processing.
- Archive files (
.a
,.lib
,.rlib
)- The archive entry files will be extracted to a temporary directory for processing.
Including specific functions¶
Sometimes you may not want to include every function but a subset, in that case you can tag functions to include with
the command WARP\\Include Function
(or add the tag yourself with "WARP: Selected Function"
) once you have selected all
the functions you want, you can run the create command. If you are trying to add functions to an existing warp file, you
will be prompted whether you want to keep the existing data, you will want to say yes.
File size¶
Information in the WARP file will be deduplicated across all processed files automatically. If your files are too large, try and adjust the file data to something like "Symbols" only, and if you are looking to make the files load quicker, turn off compression.
Overwriting Matched Functions¶
WARP will not always be able to identify the unique function in the matcher. In this case we give the user a few options for resolving the matched function:
- Using the WARP sidebar, you can view and set the matched function
- In the "Current Function" tab, double-click on any possible function (or right-click and hit Apply)
- Using the API, you can query possible functions and then set the matched function
All matched functions are stored in the BNDB, so you do not need to provide signature files when distributing databases.
API¶
To create, query and load WARP data programmatically, we provide a Python API. For those looking to interact with WARP from Rust because the plugin is open source, you can depend directly on the Rust plugin, skipping the FFI entirely.
Python example¶
This example will open a binary in Binary Ninja then output a WARP signature file.
import sys
from pathlib import Path
from binaryninja import load
from binaryninja.warp import WarpContainer, WarpFunction, WarpTarget
def process_binary(input_file: str, output_dir: str) -> None:
input_path = Path(input_file)
output_dir = Path(output_dir)
output_dir.mkdir(parents=True, exist_ok=True)
bv = load(input_path)
bv.update_analysis_and_wait()
if not bv:
return
# Sources exist only in containers, so we will just pull off the first available container.
# In the future we might make container construction available to the API.
container = WarpContainer.all()[0]
output_file = output_dir / f"{input_path.stem}_analysis.warp"
# Add the source so we can add functions to it and then commit it (write to disk)
source = container.add_source(str(output_file))
# NOTE: You probably want to pull the platform from the function, but for this example it's fine.
target = WarpTarget(bv.platform)
# NOTE: You probably want to filter for functions with actual annotations, no point to signature a function with no symbol.
functions_to_warp = [WarpFunction(func) for func in bv.functions]
container.add_functions(target, source, functions_to_warp)
# Actually write the warp file to disk.
container.commit_source(source)
bv.file.close()
if __name__ == "__main__":
if len(sys.argv) != 3:
print(f"Usage: {sys.argv[0]} <input_binary> <output_directory>")
sys.exit(1)
process_binary(sys.argv[1], sys.argv[2])
The flexibility of the API allows you to include or exclude any functions you want from the creation of the signature file.
Troubleshooting¶
Why do these very similar functions have a different function GUID?¶
WARP is an exact function matcher, even small changes like a different register will change the GUID. The point of WARP is to provide an inexpensive base layer of function matching and an open source file format for sharing analysis information.
Why does the exact same function have a different function GUID?¶
Using the render layer, you can identify differences in the two functions guid construction:
- Highlighted red is "variant instruction"
- Highlighted yellow is "computed variant instruction"
- Highlighted black is "blacklisted instruction"
The function guid will differ if the instruction highlights are not exactly the same across all instructions in both functions.
No relocatable regions found¶
When running the matcher manually, you may get a warning about no relocatable regions found; this means you have no defined sections or segments in your view. For WARP to work we must have some range of address space to work with, without it the function GUID's will likely be inconsistent if the functions can be based at different addresses.
Glossary¶
Here is a list of terms used and a simplified description, please see the WARP spec repository for a more detailed description.
Target¶
A Target defines platform-specific information needed to filter out irrelevant WARP information.
Container¶
A Container stores and manages WARP data, whether in memory, on disk or over the network. Each container has its own collection of sources.
Source¶
A Source is a collection of WARP data within a container, like a file containing function and type information.
Function¶
A Function in WARP represents the collection of metadata that we wish to transfer, such as the symbol, comments and types.
Function GUID¶
A Function GUID is a unique ID derived from the contents of the function, allowing matching across different binaries.
Constraint¶
A Constraint helps ensure accurate function matching by verifying specific properties are shared between functions. For example, a referenced function would be used as a constraint.