md5deep is a

software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

package used in the

computer security Computer security, cybersecurity (cyber security), or information technology security (IT security) is the protection of computer systems and networks from attack by malicious actors that may result in unauthorized information disclosure, the ...

system administration A system administrator, or sysadmin, or admin is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems, especially multi-user computers, such as servers. The system administrator seeks to ensu ...

and

computer forensics Computer forensics (also known as computer forensic science) is a branch of digital forensic science pertaining to evidence found in computers and digital storage media. The goal of computer forensics is to examine digital media in a forensical ...

communities to run large numbers of files through any of several different

cryptographic Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adve ...

digests Digest may refer to: Biology *Digestion of food *Restriction digest Literature and publications *'' The Digest'', formerly the English and Empire Digest *Digest size magazine format * ''Digest'' (Roman law), also known as ''Pandects'', a digest ...

. It was originally authored by Jesse Kornblum, at the time a special agent of the

Air Force Office of Special Investigations The Department of the Air Force Office of Special Investigations (OSI) is a U.S. federal law enforcement agency that reports directly to the Secretary of the Air Force. OSI is also a U.S. Air Force field operating agency under the administrative ...

. , he still maintains it. The name ''md5deep'' is misleading. Since version 2.0, the ''md5deep'' package contains several different programs able to perform MD5,

SHA-1 In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecima ...

SHA-256 SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression ...

, Tiger192 and

Whirlpool A whirlpool is a body of rotating water produced by opposing currents or a current running into an obstacle. Small whirlpools form when a bath or a sink is draining. More powerful ones formed in seas or oceans may be called maelstroms ( ). ''Vo ...

digests, each of them named by the digest type followed by the word "deep". Thus, the name may confuse some people into thinking it only provides the MD5 algorithm when the package supports many more. ''md5deep'' can be invoked in several different ways. Typically users operate it

recursively Recursion (adjective: ''recursive'') occurs when a thing is defined in terms of itself or of its type. Recursion is used in a variety of disciplines ranging from linguistics to logic. The most common application of recursion is in mathematics ...

, where ''md5deep'' walks through one

directory Directory may refer to: * Directory (computing), or folder, a file system structure in which to store computer files * Directory (OpenVMS command) * Directory service, a software application for organizing information about a computer network's u ...

at a time giving digests of each file found, and recursing into any subdirectories within. Its recursive behavior is approximately a

depth-first search Depth-first search (DFS) is an algorithm for traversing or searching tree or graph data structures. The algorithm starts at the root node (selecting some arbitrary node as the root node in the case of a graph) and explores as far as possible alon ...

, which has the benefit of presenting files in

lexicographical order In mathematics, the lexicographic or lexicographical order (also known as lexical order, or dictionary order) is a generalization of the alphabetical order of the dictionaries to sequences of ordered symbols or, more generally, of elements of a ...

. On

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

systems, similar functionality can be often obtained by combining

find Find, FIND or Finding may refer to: Computing * find (Unix), a command on UNIX platforms * find (Windows), a command on DOS/Windows platforms Books * ''The Find'' (2010), by Kathy Page * ''The Find'' (2014), by William Hope Hodgson Film and tel ...

with hashing utilities such as

md5sum is a computer program A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible compon ...

sha256sum is a computer program that calculates and verifies SHA-1 Cryptographic hash function, hashes. It is commonly used to verify the integrity of files. It (or a variant) is installed by default on most Linux distributions. Typically distributed alo ...

tthsum In cryptography and computer science, a hash tree or Merkle tree is a tree in which every "leaf" (node) is labelled with the cryptographic hash of a data block, and every node that is not a leaf (called a ''branch'', ''inner node'', or ''inode'') ...

. ''md5deep'' exists for

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

and most

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

-based systems, including

OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

. It is present in OS X's '' Fink'', '' Homebrew'' and

MacPorts MacPorts, formerly DarwinPorts, is a package manager for macOS and Darwin. It is an open-source software project that aims to simplify the installation of other open source software. It's similar in function to Fink and the BSD ports collections ...

projects. Binary packages exist for most

free Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procur ...

Unix systems. Many vendors initially resist including ''md5deep'' as they mistakenly believe its functions can be reproduced with one line of shell scripting. The matching function of the program, however, cannot be done easily in shell. Because ''md5deep'' was written by an employee of the U.S. government, on government time, it is in the

public domain The public domain (PD) consists of all the creative work A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...

. Other software surrounding it, such as graphical front-ends, may be copyrighted.

References

External links

* {{Official website, https://github.com/jessek/hashdeep/ at ''

GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous ...

'' Computer security software Public-domain software with source code Free software programmed in C

See also

References

External links