6 .Nm md5 , sha1 , sha256 , sha384 , sha512, sha512t256, rmd160
7 .Nd calculate a message-digest fingerprint (checksum) for a file
46 .Nm md5 , sha1 , sha256 , sha384 , sha512, sha512t256
49 utilities take as input a message of arbitrary length and produce as
55 It is conjectured that it is computationally infeasible to
56 produce two messages having the same message digest, or to produce any
57 message having a given prespecified target message digest.
59 .Tn MD5 , SHA-1 , SHA-256 , SHA-384 , SHA-512
62 algorithms are intended for digital signature applications, where a
65 in a secure manner before being encrypted with a private
67 key under a public-key cryptosystem such as
71 has been completely broken as far as finding collisions is
72 concerned, and should not be relied upon to produce unique outputs.
75 should not be used as part of a cryptographic signature scheme.
76 At the current time (2014-05-17) there is no publicly known method to
78 MD5, i.e., to find an input given a hash value.
81 currently (2014-05-17) has no known collisions, but an attack has been
82 found which is faster than a brute-force search, placing the security of
89 truncated to only 256 bits.
90 On 64-bit hardware, this algorithm is approximately 50% faster than
92 but with the same level of security.
93 The hashes are not interchangeable.
95 It is recommended that all new applications use
97 instead of one of the other hash functions.
99 The following options may be used in any combination and must
100 precede any files named on the command line.
101 The hexadecimal checksum of each file listed on the command line is printed
102 after the options are processed.
103 .Bl -tag -width indent
105 Compare the digest of the file against this string.
106 .Pq Note that this option is not yet useful if multiple files are specified.
108 Print a checksum of the given
111 Echo stdin to stdout and append the checksum to stdout.
113 Quiet mode \(em only the checksum is printed out.
118 Reverses the format of the output.
119 This helps with visual diffs.
121 when combined with the
125 Run a built-in time trial.
127 Run a built-in test script.
131 .Nm md5 , sha1 , sha256 , sha512, sha512t256
134 utilities exit 0 on success,
135 1 if at least one of the input files could not be read,
136 and 2 if at least one file does not have the same hash as the
149 .%T The MD5 Message-Digest Algorithm
154 .%T The Secure Hash Standard
158 .%A D. Eastlake and P. Jones
159 .%T US Secure Hash Algorithm 1
163 RIPEMD-160 is part of the ISO draft standard
164 .Qq ISO/IEC DIS 10118-3
165 on dedicated hash functions.
167 Secure Hash Standard (SHS):
168 .Pa http://csrc.nist.gov/cryptval/shs.html .
171 .Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
173 This program is placed in the public domain for free general use by
176 Support for SHA-1 and RIPEMD-160 has been added by
177 .An Oliver Eikemeier Aq Mt eik@FreeBSD.org .