sbommerge 0.2.0
Software Bill of Material (SBOM) merge tool
License: Apache-2.0
Requires Python: >=3.7
Keywords: security,tools,SBOM,DevSecOps,SPDX,CycloneDX

# SBOMMerge

SBOMMerge merges two Software Bill of Materials (SBOMs) documents together. It supports SBOMs created in both
[SPDX](https://www.spdx.org) and [CycloneDX](https://www.cyclonedx.org) formats.

## Installation

To install use the following command:

`pip install sbommerge`

Alternatively, just clone the repo and install dependencies using the following command:

`pip install -U -r requirements.txt`

The tool requires Python 3 (3.7+). It is recommended to use a virtual python environment especially
if you are using different versions of python. `virtualenv` is a tool for setting up virtual python environments which
allows you to have all the dependencies for the tool set up in a single environment, or have different environments set
up for testing using different versions of Python.

## Usage

```bash
usage: sbommerge [-h] [--sbom {auto,spdx,cyclonedx}] [-d] [--format {tag,json,yaml}] [-o OUTPUT_FILE] [-V] FILE1 FILE2

SBOMMerge merges two Software Bill of Materials (SBOMs) documents together.

positional arguments:
  FILE1                 first SBOM file
  FILE2                 second SBOM file

options:
  -h, --help            show this help message and exit
  -V, --version         show program's version number and exit

Input:
  --sbom {auto,spdx,cyclonedx}
                        specify type of sbom to merge (default: auto)

Output:
  -d, --debug           show debug information
  --format {tag,json,yaml}
                        specify format of generated sbom (default: tag)
  -o OUTPUT_FILE, --output-file OUTPUT_FILE
                        output filename (default: output to stdout)
```
						
## Operation

The `--sbom` option is used to specify the format of the SBOM files. The default is for the type and format of the SBOM to be
automatically detected based on the extension of the file name.

| SBOM Type | Version   | Extension      |Format         |
| --------- | --------- | ---------------|---------------|
| SPDX      | 2.3       | .spdx          | TagValue      |
| SPDX      | 2.3       | .spdx.json     | JSON          |
| SPDX      | 2.3       | .spdx.yml      | YAML          |
| SPDX      | 2.3       | .spdx.yaml     | YAML          |
| CycloneDX | 1.4       | .json          | JSON          |
| CycloneDX | 1.5       | .json          | JSON          |

Details of the formats for each of the supported SBOM formats are available for
[SPDX](https://spdx.dev/) and [CycloneDX](https://cyclonedx.org/).

For SPDX SBOM files, it is assumed that the name of a Package precedes the version information for the package.
Only modules with a package name and associated version information shall be processed.

The `--output-file` option is used to control the destination of the output generated by the tool. The
default is to report to the console but can be stored in a file (specified using `--output-file` option).

## Implementation Notes

The following design decisions have been made in processing the SBOM files:

1. Package data is merged if the package version matches. Otherwise separate packages will be created.

2. It is assumed that the SBOM is valid and contains syntactically valid data. Invalid files will be silently ignored.

3. A non-zero return value indicates that differences were detected.

## License

Licensed under the Apache 2.0 Licence.

## Limitations

This tool is meant to support software development and security audit functions. However the usefulness of the tool is dependent on the SBOM data
which is provided to the tool. Unfortunately, the tool is unable to determine the validity or completeness of such a SBOM file; users of the tool
are therefore reminded that they should assert the quality of any data which is provided to the tool.

## Feedback and Contributions

Bugs and feature requests can be made via GitHub Issues.