Introduction

Microsoft Application Inspector is a software source code analysis tool that helps identify and surface well-known features and other interesting characteristics of source code to aid in determining what the software is or what it does by conducting an inspecting scan.

Application Inspector is different from traditional static analysis tools in that it doesn't attempt to identify "good" or "bad" patterns; it simply reports what it finds against a set of over 500 rule patterns for feature detection including features that impact security such as the use of cryptography and more. This can be extremely helpful in reducing the time needed to determine what Open Source or other components do by examining the source directly rather than trusting to limited documentation or recommendations.

The tool includes several output formats with the default being an html report similar to the one shown here.

It includes a filterable confidence indicator to help minimize false positives matches as well as customizable default rules and conditional match logic.

Be sure to see our project wiki page for more help https://Github.com/Microsoft/ApplicationInspector/wiki for illustrations and additional information and help.

Goals

Application Inspector can inform you better for choosing the best component to meet your needs with a smaller footprint of unknowns which is very important to keeping the attack surface small. It enables you to avoid inclusion of features you don't want for the problem, system or context your app will run in.

Basically, we created Application Inspector to help us identify risky third party software components based on their specific features, but the tool is helpful in many non-security contexts as well. For instance, it can also help identify feature deltas or changes between versions which can be critical for detecting injection of backdoors.

Using Application Inspector to automate detection of features of interest or changes or to build a data repository of metadata regarding your enterprise applications is achievable.

Application Inspector v1.0 is now in GENERAL AUDIENCE release status. Your feedback is important to us. If you're interested in contributing, please review the CONTRIBUTING.md.

Using Application Inspector

To use Application Inspector, download the relevant binary (either platform-specific or the multi-platform .NET Core release). If you use the .NET Core version, you will need to have .NET Core 3.0 or later installed.

It might be valuable to consult the project wiki for additional background on Rules, Tags and more used to identify features. Tags are used as a systematic heirarchal nomenclature e.g. Cryptography.Protocol.TLS to more easily represent features.

Usage

Application Inspector is a command-line tool. Run it from a command line in Windows, Linux, or MacOS.

> dotnet AppInspector.dll or on *Windows* simply AppInspector.exe <command> <options>

Microsoft Application Inspector 1.0.17
ApplicationInspector 1.0.17

(c) Microsoft Corporation. All rights reserved

ERROR(S):
  No verb selected.

  analyze        Inspect source directory/file/compressed file (.tgz|zip) against defined characteristics
  tagdiff        Compares unique tag values between two source paths
  tagtest        Test presence of smaller set or custom tags in source (compare or verify modes)
  exporttags     Export default unique rule tags to view what features may be detected
  verifyrules    Verify rules syntax is valid
  help           Display more information on a specific command
  version        Display version information

Examples:

Command Help

  Usage: dotnet AppInspector.dll [arguments] [options]

  dotnet AppInspector.dll -description of available commands
  dotnet AppInspectorldll <command> -options description for a given command

Analyze Command

  Usage: dotnet AppInspector.dll analyze [arguments] [options]

  Arguments:
  -s, --source-path             Required. Path to source code to inspect (required)
  -o, --output-file-path        Path to output file
  -f, --output-file-format      (Default: html) Output format [html|json|text]
  -e, --text-format             (Default: Tag:%T,Rule:%N,Ruleid:%R,Confidence:%X,File:%F,Sourcetype:%t,Line:%L,Sample:%m) 
  -r, --custom-rules-path       Custom rules path
  -t, --tag-output-only         (Default: false) Output only contains identified tags
  -i, --ignore-default-rules    (Default: false) Ignore default rules bundled with application
  -d, --allow-dup-tags          (Default: false) Output only contains non-unique tag matches
  -c, --confidence-filters      (Default: high,medium) Output only if matches rule pattern confidence [<value>,] [high|medium|low]
  -k, --include-sample-paths    (Default: false) Include source files with (sample,example,test,.vs,.git) in pathname in analysis
  -x, --console-verbosity       (Default: medium) Console verbosity [high|medium|low|none]
  -l, --log-file-path           Log file path
  -v, --log-file-level          (Default: Error) Log file level [Debug|Info|Warn|Error|Fatal|Off]

Scan a project directory, with output sent to "output.html" (default behavior includes launching default browser to this file)

  dotnet AppInspector.dll analyze -s /home/user/myproject 

Add custom rules (can be specified multiple times)

  dotnet AppInspector.dll analyze -s /home/user/myproject -r /my/rules/directory -r /my/other/rules

Write to JSON format

  dotnet AppInspector.dll analyze -s /home/user/myproject -f json

Tagdiff Command

Use to analyze and report on differences in tags (features) between two project or project versions e.g. v1, v2 to see what changed

  Usage: dotnet AppInspector.dll tagdiff [arguments] [options]

  Arguments:
  --src1                        Required. Source 1 to compare (required)
  --src2                        Required. Source 2 to compare (required
  -t, --test-type               (Default: equality) Type of test to run [equality|inequality]
  -r, --custom-rules-path       Custom rules path
  -i, --ignore-default-rules    (Default: false) Ignore default rules bundled with application
  -o, --output-file-path        Path to output file
  -x, --console-verbosity       Console verbosity [high|medium|low
  -l, --log-file-path           Log file path
  -v, --log-file-level          Log file level [error|trace|debug|info]

Simplist way to see the delta in tag features between two projects

  dotnet AppInspector.dll tagdiff /home/user/project1 /home/user/project2

Basic use

  dotnet AppInspector.dll tagdiff /home/user/project1 /home/user/project2 -t equality

Basic use

  dotnet AppInspector.dll tagdiff /home/user/project1 /home/user/project2 -t inequality

TagTest Command

Used to verify (pass/fail) that a specified set of rule tags is present or not present in a project e.g. user only wants to know true/false if crytography is present as expected or if personal data is not present as expected and get a simple yes/no result rather than a full analyis report.

Note: The user is expected to use the custom-rules-path option rather than the default ruleset because it is unlikely that any source package would contain all of the default rules. Instead, create a custom path and rule set as needed or specify a path using the custom-rules-path to point only to the rule(s) needed from the default set.
Otherwise, testing for all default rules present in source will likely yield a false or fail result in most cases.

  Usage: dotnet AppInspector.dll tagtest [arguments] [options

  Arguments:
  -s, --source-path             Required. Source to test (required)
  -t, --test-type               (Default: rulespresent) Test to perform [rulespresent|rulesnotpresent]
  -r, --custom-rules-path       Custom rules path 
  -i, --ignore-default-rules    (Default: true) Ignore default rules bundled with application
  -o, --output-file-path        Path to output file
  -x, --console-verbosity       Console verbosity [high|medium|low
  -l, --log-file-path           Log file path
  -v, --log-file-level          Log file level

Simplest use to see if a set of rules are all present in a project

  dotnet AppInspector.dll tagtest /home/user/project1 -r /home/user/myrules.json

Basic use

  dotnet AppInspector.dll tagtest /home/user/project1 -r /home/user/myrules.json -t rulespresent

Basic use

  dotnet AppInspector.dll tagtest /home/user/project1 -r /home/user/myrules.json -t rulesnotpresent

ExportTags Command

Simple export of the ruleset schema for tags representing what features are supported for detection

  Usage: dotnet AppInspector.dll exporttags [arguments] [options]

  Arguments:
  -r, --custom-rules-path       Custom rules path
  -i, --ignore-default-rules    (Default: false) Ignore default rules bundled with application
  -o, --output-file-path        Path to output file
  -x, --console-verbosity       Console verbosity [high|medium|low

Export default rule tags to console

  dotnet AppInspector.dll exporttags

Using output file

  dotnet AppInspector.dll exporttags -o /home/user/myproject/exportags.txt

With custom rules and output file

  dotnet AppInspector.dll exporttags -r /home/user/myproject/customrules -o /hom/user/myproject/exportags.txt

Verify Command

Verification that ruleset is compatible and error free for import and analysis

  Usage: dotnet AppInspector.dll verifyrules [arguments]

  Arguments:
  -r, --custom-rules-path       Custom rules path
  -i, --ignore-default-rules    (Default: false) Ignore default rules bundled with application
  -o, --output-file-path        Path to output file
  -x, --console-verbosity       Console verbosity [high|medium|low

Simplist case to verify default rules

  dotnet AppInspector.dll verifyrules

Using custom rules only

  dotnet AppInspector.dll verifyrules -r /home/user/myproject/customrules -i

Build Instructions

Building from source requires .NET Core 3.0. Standard dotnet build commands can be run from the root source folder.

Framework Dependent

  dotnet build -c Release

Platform Targeted Portable

  dotnet publish -c Release -r win-x86
  dotnet publish -c Release -r linux-x64
  dotnet publish -c Release -r osx-x64