6 .Nm md5 , sha1 , sha256 , sha512, rmd160
7 .Nd calculate a message-digest fingerprint (checksum) for a file
36 .Nm md5 , sha1 , sha256 , sha512
39 utilities take as input a message of arbitrary length and produce as
45 It is conjectured that it is computationally infeasible to
46 produce two messages having the same message digest, or to produce any
47 message having a given prespecified target message digest.
49 .Tn MD5 , SHA-1 , SHA-256 , SHA-512
52 algorithms are intended for digital signature applications, where a
55 in a secure manner before being encrypted with a private
57 key under a public-key cryptosystem such as
61 has been completely broken as far as finding collisions is
62 concerned, and should not be relied upon to produce unique outputs.
65 should not be used as part of a cryptographic signature scheme.
66 At the current time (2014-05-17) there is no publicly known method to
68 MD5, i.e., to find an input given a hash value.
71 currently (2014-05-17) has no known collisions, but an attack has been
72 found which is faster than a brute-force search, placing the security of
76 It is recommended that all new applications use
78 instead of one of the other hash functions.
80 The following options may be used in any combination and must
81 precede any files named on the command line.
82 The hexadecimal checksum of each file listed on the command line is printed
83 after the options are processed.
84 .Bl -tag -width indent
86 Compare the digest of the file against this string.
87 .Pq Note that this option is not yet useful if multiple files are specified.
89 Print a checksum of the given
92 Echo stdin to stdout and append the checksum to stdout.
94 Quiet mode \(em only the checksum is printed out.
99 Reverses the format of the output.
100 This helps with visual diffs.
102 when combined with the
106 Run a built-in time trial.
108 Run a built-in test script.
112 .Nm md5 , sha1 , sha256 , sha512
115 utilities exit 0 on success,
116 1 if at least one of the input files could not be read,
117 and 2 if at least one file does not have the same hash as the
129 .%T The MD5 Message-Digest Algorithm
134 .%T The Secure Hash Standard
138 .%A D. Eastlake and P. Jones
139 .%T US Secure Hash Algorithm 1
143 RIPEMD-160 is part of the ISO draft standard
144 .Qq ISO/IEC DIS 10118-3
145 on dedicated hash functions.
147 Secure Hash Standard (SHS):
148 .Pa http://csrc.nist.gov/cryptval/shs.html .
151 .Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
153 This program is placed in the public domain for free general use by
156 Support for SHA-1 and RIPEMD-160 has been added by
157 .An Oliver Eikemeier Aq eik@FreeBSD.org .