# VCDiff
This is a wrapper around Google's open-vcdiff library, which provides
an encoder and decoder for the format described in RFC 3284:
"The VCDIFF Generic Differencing and Compression Data Format."
The encoding strategy is largely based on Bentley-McIlroy 99:
"Data Compression Using Long Common Strings.

For more details visit: http://code.google.com/p/open-vcdiff

## Installing
	# Install the gem:
	sudo gem install romanbsd-vcdiff

## Usage
	require 'VCDiff'
	
	# Encoding
	dictionary = IO.read('dictionary_file')
	modified = IO.read('modified_file')
	# Optional
	encoder.format_flags = VCDiff::VCD_FORMAT_INTERLEAVED | VCDiff::VCD_FORMAT_CHECKSUM
	encoder = VCDiff::Encoder.new(dictionary)
	res = encoder.encode(modified)
	
	# Decoding
	decoder = VCDiff::Decoder.new
	orig = decoder.decode(dictionary, res)
	
	orig == modified	# -> true


vcdiff

Roman Shterenzon

(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.

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Bad text encoding

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

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Bad semver

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

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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.

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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.

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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.

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Chrome Extension Permission

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

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Chrome Extension Wildcard Host Permission

Semantic versions published out of chronological order.

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Chronological version anomaly

Project maintainer's SSH key has been compromised.

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Compromised SSH key

(Experimental) Copyleft license information was found.

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Copyleft License

Contains a Critical Common Vulnerability and Exposure (CVE).

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Title

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High CVE

Uses debug, reflection and dynamic code execution features.

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Debug access

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Deprecated

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Deprecated SPDX exception

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Deprecated license

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Possible typosquat attack

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Dynamic require

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File dependency

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Filesystem access

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Wildcard dependency

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Git dependency

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GitHub dependency

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AI-detected potential malware

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

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AI-detected potential security risk

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Native code

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High entropy strings

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

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Unicode homoglyphs

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HTTP dependency

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

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Install scripts

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

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Invalid manifest file

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

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Invisible chars

(Experimental) Package license has recently changed.

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License change

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License exception

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

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License Policy Violation

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

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Long strings

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Major refactor

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Known malware

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Manifest confusion

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Medium CVE

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Low CVE

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(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.

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Non-existent author

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(Experimental) Package does not have a license and consumption legal status is unknown.

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Missing license

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Modified license exception

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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.

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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

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No bug tracker

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vcdiff

VCDiff

Installing

Usage

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