## What is go-eval?

go-eval evaluates boolean or basic arithmetic expressions from strings. It's analogous to a basic form of the eval function often found in dynamic languages.

Examples:
```go
res, err := EvalBool("1 > 2")
log.Print(res)
> false
```

```go
res, err := EvalBool(`(1 + 3) >= 4 && ("FOO" == "BAR" || "FOO" == "FOO")`)
log.Print(res)
> true
```

```go
res, err := EvalArithmetic("1 + 2")
log.Print(res)
> 3
```

```go
res, err := EvalArithmetic("2 - -1")
log.Print(res)
> 3
```

## How does it work?

go-eval leverges the awesome AST and Parser packages that ship in the Go standard library. It constructs an abstract syntax tree from the specified expression and walks the tree to determine the result.

## Tests

```go
go get github.com/tools/godep
godep restore
go test

PASS
ok  	github.com/diggs/go-eval	0.005s
```

## Limitations

Floats are not supported yet.
Only boolean and arithmetic expressions are supported, this doesn't support conditionals etc.

Meet the Socket Team at BlackHat and DEF CON in Las Vegas, Aug 4-6

github.com/diggs/go-eval

go-eval

(Experimental) An ambiguous license classifier was found.

What is an ambiguous license classifier?

Ambiguous License Classifier

Source files are encoded using a non-standard text encoding.

What is bad text encoding?

Bad text encoding

Package version is not a valid semantic version (semver).

What is bad semver?

Bad semver

Package has dependencies with an invalid semantic version. This could be a sign of beta, low quality, or unmaintained dependencies.

What is bad dependency semver?

Bad dependency semver

Source files contain bidirectional unicode control characters. This could indicate a Trojan source supply chain attack. See: trojansource.codes for more information.

What are bidirectional unicode control characters?

Bidirectional unicode control characters

This package has multiple bin scripts with the same name. This can cause non-deterministic behavior when installing or could be a sign of a supply chain attack.

What is bin script confusion?

Bin script confusion

This Chrome extension includes a content script '{scriptFile}' that runs on websites matching '{matches}'.

What are Chrome extension content scripts?

Chrome Extension Content Script

This Chrome extension requests access to '{host}'.

What are Chrome extension host permissions?

Chrome Extension Host Permission

This Chrome extension uses the '{permission}' permission.

What are Chrome extension permissions?

Chrome Extension Permission

This Chrome extension requests broad access to websites with the pattern '{host}'.

What are Chrome extension wildcard host permissions?

Chrome Extension Wildcard Host Permission

Semantic versions published out of chronological order.

What is a chronological version anomaly?

Chronological version anomaly

Project maintainer's SSH key has been compromised.

What is a compromised SSH key?

Compromised SSH key

(Experimental) Copyleft license information was found.

What do I need to know about license files?

Copyleft License

Contains a Critical Common Vulnerability and Exposure (CVE).

What is a critical CVE?

Title

Critical CVE

Contains a high severity Common Vulnerability and Exposure (CVE).

What is a CVE?

High CVE

Uses debug, reflection and dynamic code execution features.

What is debug access?

Debug access

The maintainer of the package marked it as deprecated. This could indicate that a single version should not be used, or that the package is no longer maintained and any new vulnerabilities will not be fixed.

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Deprecated

(Experimental) Contains a known deprecated SPDX license exception.

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Deprecated SPDX exception

(Experimental) License is deprecated which may have legal implications regarding the package's use.

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Deprecated license

Package name is similar to other popular packages and may not be the package you want.

What is a typosquat?

Possible typosquat attack

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What is dynamic require?

Dynamic require

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Empty package

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Environment variable access

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Name

Extraneous dependency

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File dependency

Accesses the file system, and could potentially read sensitive data.

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Filesystem access

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What are wildcard dependencies?

Wildcard dependency

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What are git dependencies?

Git dependency

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What are GitHub dependencies?

GitHub dependency

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AI has determined that this package may contain potential security issues or vulnerabilities.

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AI-detected potential security risk

Contains native code (e.g., compiled binaries or shared libraries). Including native code can obscure malicious behavior.

Why is native code a concern?

Native code

Contains high entropy strings. This could be a sign of encrypted data, leaked secrets or obfuscated code.

What are high entropy strings?

High entropy strings

Contains unicode homoglyphs which can be used in supply chain confusion attacks.

What are unicode homoglyphs?

Unicode homoglyphs

Contains a dependency which resolves to a remote HTTP URL which could be used to inject untrusted code and reduce overall package reliability.

What are http dependencies?

HTTP dependency

Install scripts are run when the package is installed. The majority of malware in npm is hidden in install scripts.

What is an install script?

Install scripts

Package has an invalid manifest file and can cause installation problems if you try to use it.

What is an invalid manifest file?

Invalid manifest file

Source files contain invisible characters. This could indicate source obfuscation or a supply chain attack.

What are invisible characters?

Invisible chars

(Experimental) Package license has recently changed.

What is a license change?

License change

(Experimental) Contains an SPDX license exception.

What is a license exception?

License exception

This package is not allowed per your license policy. Review the package's license to ensure compliance.

What is a license policy violation?

License Policy Violation

Contains long string literals, which may be a sign of obfuscated or packed code.

What's wrong with long strings?

Long strings

Package has recently undergone a major refactor. It may be unstable or indicate significant internal changes. Use caution when updating to versions that include significant changes.

What is a major refactor?

Major refactor

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What is known malware?

Known malware

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What is manifest confusion?

Manifest confusion

Contains a medium severity Common Vulnerability and Exposure (CVE).

What is a medium CVE?

Medium CVE

Contains a low severity Common Vulnerability and Exposure (CVE).

What is a mild CVE?

Low CVE

This package contains minified code. This may be harmless in some cases where minified code is included in packaged libraries, however packages on npm should not minify code.

What's wrong with minified code?

Minified code

(Experimental) A package's licensing information has fine-grained problems.

Misc. License Issues

The package was published by an npm account that no longer exists.

What is a non-existent author?

Non-existent author

A required dependency is not declared in package.json and may prevent the package from working.

What is a missing dependency?

Missing dependency

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Missing license

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What is a missing tarball?

Missing package tarball

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Mixed license

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What is a modified license exception?

Modified license exception

(Experimental) Package contains a modified version of an SPDX license. Please read carefully before using this code.

What is a modified license?

Modified license

What is network access?

Network access

A new npm collaborator published a version of the package for the first time. New collaborators are usually benign additions to a project, but do indicate a change to the security surface area of a package.

What is new author?

New author

Package does not specify a list of contributors or an author in package.json.

Why is contributor and author data important?

No contributors or author data

Package does not have a linked bug tracker in package.json.

Why are bug trackers important?

No bug tracker

(Experimental) License information could not be found.

No License Found

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Why are READMEs important?

No README

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Why are missing repositories important?

No repository

Package does not have any tests. This is a strong signal of a poorly maintained or low quality package.

github.com/diggs/go-eval

What is go-eval?

How does it work?

Tests

Limitations

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