6 .Nm md5 , sha1 , sha256 , sha384 , sha512, rmd160
7 .Nd calculate a message-digest fingerprint (checksum) for a file
41 .Nm md5 , sha1 , sha256 , sha384 , sha512
44 utilities take as input a message of arbitrary length and produce as
50 It is conjectured that it is computationally infeasible to
51 produce two messages having the same message digest, or to produce any
52 message having a given prespecified target message digest.
54 .Tn MD5 , SHA-1 , SHA-256 , SHA-384 , SHA-512
57 algorithms are intended for digital signature applications, where a
60 in a secure manner before being encrypted with a private
62 key under a public-key cryptosystem such as
66 has been completely broken as far as finding collisions is
67 concerned, and should not be relied upon to produce unique outputs.
70 should not be used as part of a cryptographic signature scheme.
71 At the current time (2014-05-17) there is no publicly known method to
73 MD5, i.e., to find an input given a hash value.
76 currently (2014-05-17) has no known collisions, but an attack has been
77 found which is faster than a brute-force search, placing the security of
81 It is recommended that all new applications use
83 instead of one of the other hash functions.
85 The following options may be used in any combination and must
86 precede any files named on the command line.
87 The hexadecimal checksum of each file listed on the command line is printed
88 after the options are processed.
89 .Bl -tag -width indent
91 Compare the digest of the file against this string.
92 .Pq Note that this option is not yet useful if multiple files are specified.
94 Print a checksum of the given
97 Echo stdin to stdout and append the checksum to stdout.
99 Quiet mode \(em only the checksum is printed out.
104 Reverses the format of the output.
105 This helps with visual diffs.
107 when combined with the
111 Run a built-in time trial.
113 Run a built-in test script.
117 .Nm md5 , sha1 , sha256 , sha512
120 utilities exit 0 on success,
121 1 if at least one of the input files could not be read,
122 and 2 if at least one file does not have the same hash as the
135 .%T The MD5 Message-Digest Algorithm
140 .%T The Secure Hash Standard
144 .%A D. Eastlake and P. Jones
145 .%T US Secure Hash Algorithm 1
149 RIPEMD-160 is part of the ISO draft standard
150 .Qq ISO/IEC DIS 10118-3
151 on dedicated hash functions.
153 Secure Hash Standard (SHS):
154 .Pa http://csrc.nist.gov/cryptval/shs.html .
157 .Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
159 This program is placed in the public domain for free general use by
162 Support for SHA-1 and RIPEMD-160 has been added by
163 .An Oliver Eikemeier Aq Mt eik@FreeBSD.org .