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
74 algorithms have been proven to be vulnerable to practical collision
75 attacks and should not be relied upon to produce unique outputs, nor
76 should they be used as part of a cryptographic signature scheme.
77 As of 2017-03-02, there is no publicly known method to
79 either algorithm, i.e. to find an input that produces a specific
85 truncated to only 256 bits.
86 On 64-bit hardware, this algorithm is approximately 50% faster than
88 but with the same level of security.
89 The hashes are not interchangeable.
91 It is recommended that all new applications use
93 instead of one of the other hash functions.
95 The following options may be used in any combination and must
96 precede any files named on the command line.
97 The hexadecimal checksum of each file listed on the command line is printed
98 after the options are processed.
99 .Bl -tag -width indent
101 Compare the digest of the file against this string.
102 .Pq Note that this option is not yet useful if multiple files are specified.
104 Print a checksum of the given
107 Echo stdin to stdout and append the checksum to stdout.
109 Quiet mode \(em only the checksum is printed out.
114 Reverses the format of the output.
115 This helps with visual diffs.
117 when combined with the
121 Run a built-in time trial.
123 Run a built-in test script.
127 .Nm md5 , sha1 , sha256 , sha512, sha512t256
130 utilities exit 0 on success,
131 1 if at least one of the input files could not be read,
132 and 2 if at least one file does not have the same hash as the
145 .%T The MD5 Message-Digest Algorithm
150 .%T The Secure Hash Standard
154 .%A D. Eastlake and P. Jones
155 .%T US Secure Hash Algorithm 1
159 RIPEMD-160 is part of the ISO draft standard
160 .Qq ISO/IEC DIS 10118-3
161 on dedicated hash functions.
163 Secure Hash Standard (SHS):
164 .Pa http://csrc.nist.gov/cryptval/shs.html .
167 .Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
169 This program is placed in the public domain for free general use by
172 Support for SHA-1 and RIPEMD-160 has been added by
173 .An Oliver Eikemeier Aq Mt eik@FreeBSD.org .