6 .Nm md5 , sha1 , sha256, rmd160
7 .Nd calculate a message-digest fingerprint (checksum) for a file
27 .Nm md5 , sha1 , sha256
30 utilities take as input a message of arbitrary length and produce as
36 It is conjectured that it is computationally infeasible to
37 produce two messages having the same message digest, or to produce any
38 message having a given prespecified target message digest.
40 .Tn MD5 , SHA-1 , SHA-256
43 algorithms are intended for digital signature applications, where a
46 in a secure manner before being encrypted with a private
48 key under a public-key cryptosystem such as
52 has been completely broken as far as finding collisions is
53 concerned, and should not be relied upon to produce unique outputs.
56 should not be used as part of a cryptographic signature scheme.
57 At the current time (2009-01-06) there is no publicly known method to
59 MD5, i.e., to find an input given a hash value.
62 currently (2009-01-06) has no known collisions, but an attack has been
63 found which is faster than a brute-force search, placing the security of
67 It is recommended that all new applications use
69 instead of one of the other hash functions.
71 The following options may be used in any combination and must
72 precede any files named on the command line.
73 The hexadecimal checksum of each file listed on the command line is printed
74 after the options are processed.
75 .Bl -tag -width indent
77 Print a checksum of the given
80 Echo stdin to stdout and append the checksum to stdout.
82 Quiet mode - only the checksum is printed out.
87 Reverses the format of the output.
88 This helps with visual diffs.
90 when combined with the
94 Run a built-in time trial.
96 Run a built-in test script.
100 .Nm md5 , sha1 , sha256
103 utilities exit 0 on success,
104 and 1 if at least one of the input files could not be read.
113 .%T The MD5 Message-Digest Algorithm
118 .%T The Secure Hash Standard
122 .%A D. Eastlake and P. Jones
123 .%T US Secure Hash Algorithm 1
127 RIPEMD-160 is part of the ISO draft standard
128 .Qq ISO/IEC DIS 10118-3
129 on dedicated hash functions.
131 Secure Hash Standard (SHS):
132 .Pa http://csrc.nist.gov/cryptval/shs.html .
135 .Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
137 This program is placed in the public domain for free general use by
140 Support for SHA-1 and RIPEMD-160 has been added by
141 .An Oliver Eikemeier Aq eik@FreeBSD.org .