6 .Nm md5 , sha1 , sha224 , sha256 , sha384 , sha512 , sha512t256 , rmd160 ,
7 .Nm skein256 , skein512 , skein1024 ,
8 .Nm md5sum , sha1sum , sha224sum , sha256sum , sha384sum , sha512sum ,
9 .Nm sha512t256sum , rmd160sum , skein256sum , skein512sum , skein1024sum
10 .Nd calculate a message-digest fingerprint (checksum) for a file
24 (All other hashes have the same options and usage.)
27 .Nm md5 , sha1 , sha224 , sha256 , sha384 , sha512 , sha512t256 , rmd160 ,
28 .Nm skein256 , skein512 ,
31 utilities take as input a message of arbitrary length and produce as
38 .Nm md5sum , sha1sum , sha224sum , sha256sum , sha384sum , sha512sum ,
39 .Nm sha512t256sum , rmd160sum , skein256sum , skein512sum ,
42 utilities do the same, but default to the reversed format of
46 It is conjectured that it is computationally infeasible to
47 produce two messages having the same message digest, or to produce any
48 message having a given prespecified target message digest.
49 The SHA-224 , SHA-256 , SHA-384 , SHA-512, RIPEMD-160,
51 algorithms are intended for digital signature applications, where a
54 in a secure manner before being encrypted with a private
56 key under a public-key cryptosystem such as RSA.
58 The MD5 and SHA-1 algorithms have been proven to be vulnerable to practical
59 collision attacks and should not be relied upon to produce unique outputs,
60 .Em nor should they be used as part of a cryptographic signature scheme.
61 As of 2017-03-02, there is no publicly known method to
63 either algorithm, i.e., to find an input that produces a specific
66 SHA-512t256 is a version of SHA-512 truncated to only 256 bits.
67 On 64-bit hardware, this algorithm is approximately 50% faster than SHA-256 but
68 with the same level of security.
69 The hashes are not interchangeable.
71 It is recommended that all new applications use SHA-512 or SKEIN-512
72 instead of one of the other hash functions.
74 The following options may be used in any combination and must
75 precede any files named on the command line.
76 The hexadecimal checksum of each file listed on the command line is printed
77 after the options are processed.
78 .Bl -tag -width indent
82 programs separate hash and digest with a blank followed by an asterisk instead
83 of by 2 blank characters for full compatibility with the output generated by the
84 coreutils versions of these programs.
86 If the program was called with a name that does not end in
88 compare the digest of the file against this string.
91 option, the calculated digest is printed in addition to the exit status being set.
92 .Pq Note that this option is not yet useful if multiple files are specified.
94 If the program was called with a name that does end in
96 the file passed as argument must contain digest lines generated by the same
97 digest algorithm with or without the
100 .Pq i.e., in either classical BSD format or in GNU coreutils format .
101 A line with the file name followed by a colon
103 and either OK or FAILED is written for each well-formed line in the digest file.
104 If applicable, the number of failed comparisons and the number of lines that were
105 skipped since they were not well-formed are printed at the end.
108 option can be used to quiesce the output unless there are mismatched entries in
112 Print a checksum of the given
115 Echo stdin to stdout and append the checksum to stdout.
117 Quiet mode \(em only the checksum is printed out.
122 Reverses the format of the output.
123 This helps with visual diffs.
125 when combined with the
129 Run a built-in time trial.
132 versions, this is a nop for compatibility with coreutils.
134 Run a built-in test script.
138 .Nm md5 , sha1 , sha224 , sha256 , sha512 , sha512t256 , rmd160 ,
139 .Nm skein256 , skein512 ,
142 utilities exit 0 on success,
143 1 if at least one of the input files could not be read,
144 and 2 if at least one file does not have the same hash as the
148 Calculate the MD5 checksum of the string
150 .Bd -literal -offset indent
152 MD5 ("Hello") = 8b1a9953c4611296a827abf8c47804d7
155 Same as above, but note the absence of the newline character in the input
157 .Bd -literal -offset indent
158 $ echo -n Hello | md5
159 8b1a9953c4611296a827abf8c47804d7
162 Calculate the checksum of multiple files reversing the output:
163 .Bd -literal -offset indent
164 $ md5 -r /boot/loader.conf /etc/rc.conf
165 ada5f60f23af88ff95b8091d6d67bef6 /boot/loader.conf
166 d80bf36c332dc0fdc479366ec3fa44cd /etc/rc.conf
170 variants put 2 blank characters between hash and file name for full compatibility
171 with the coreutils versions of these commands.
175 .Pa /boot/loader.conf
178 Then calculate the checksum again and validate it against the checksum string
182 .Bd -literal -offset indent
183 $ md5 /boot/loader.conf > digest && md5 -c $(cut -f2 -d= digest) /boot/loader.conf
184 MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6
187 Same as above but comparing the digest against an invalid string
188 .Pq Dq randomstring ,
189 which results in a failure.
190 .Bd -literal -offset indent
191 $ md5 -c randomstring /boot/loader.conf
192 MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6 [ Failed ]
195 If invoked with a name ending in
199 option does not compare against a hash string passed as parameter.
200 Instead, it expects a digest file, as created under the name
203 .Pa /boot/loader.conf
204 in the example above.
205 .Bd -literal -offset indent
206 $ md5 -c digest /boot/loader.conf
207 /boot/loader.conf: OK
210 The digest file may contain any number of lines in the format generated with or without the
213 .Pq i.e., in either classical BSD format or in GNU coreutils format .
214 If a hash value does not match the file, FAILED is printed instead of OK.
226 .%T The MD5 Message-Digest Algorithm
231 .%T The Secure Hash Standard
235 .%A D. Eastlake and P. Jones
236 .%T US Secure Hash Algorithm 1
240 RIPEMD-160 is part of the ISO draft standard
241 .Qq ISO/IEC DIS 10118-3
242 on dedicated hash functions.
244 Secure Hash Standard (SHS):
245 .Pa https://www.nist.gov/publications/secure-hash-standard-shs
248 .Pa https://homes.esat.kuleuven.be/~bosselae/ripemd160.html
250 All of the utilities that end in
252 are intended to be compatible with the GNU coreutils programs.
253 However, the long option functionality is not provided.
255 This program is placed in the public domain for free general use by
258 Support for SHA-1 and RIPEMD-160 has been added by
259 .An Oliver Eikemeier Aq Mt eik@FreeBSD.org .