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.
89 .Pq Note that this option is not yet useful if multiple files are specified.
91 If the program was called with a name that does end in
93 the file passed as argument must contain digest lines generated by the same
94 digest algorithm with or without the
97 .Pq i.e. in either classical BSD format or in GNU coreutils format .
98 A line with the file name followed by a colon
100 and either OK or FAILED is written for each well-formed line in the digest file.
101 If applicable, the number of failed comparisons and the number of lines that were
102 skipped since they were not well-formed are printed at the end.
105 option can be used to quiesce the output unless there are mismatched entries in
109 Print a checksum of the given
112 Echo stdin to stdout and append the checksum to stdout.
114 Quiet mode \(em only the checksum is printed out.
119 Reverses the format of the output.
120 This helps with visual diffs.
122 when combined with the
126 Run a built-in time trial.
129 versions, this is a nop for compatibility with coreutils.
131 Run a built-in test script.
135 .Nm md5 , sha1 , sha224 , sha256 , sha512 , sha512t256 , rmd160 ,
136 .Nm skein256 , skein512 ,
139 utilities exit 0 on success,
140 1 if at least one of the input files could not be read,
141 and 2 if at least one file does not have the same hash as the
145 Calculate the MD5 checksum of the string
147 .Bd -literal -offset indent
149 MD5 ("Hello") = 8b1a9953c4611296a827abf8c47804d7
152 Same as above, but note the absence of the newline character in the input
154 .Bd -literal -offset indent
155 $ echo -n Hello | md5
156 8b1a9953c4611296a827abf8c47804d7
159 Calculate the checksum of multiple files reversing the output:
160 .Bd -literal -offset indent
161 $ md5 -r /boot/loader.conf /etc/rc.conf
162 ada5f60f23af88ff95b8091d6d67bef6 /boot/loader.conf
163 d80bf36c332dc0fdc479366ec3fa44cd /etc/rc.conf
167 variants put 2 blank characters between hash and file name for full compatibility
168 with the coreutils versions of these commands.
172 .Pa /boot/loader.conf
175 Then calculate the checksum again and validate it against the checksum string
179 .Bd -literal -offset indent
180 $ md5 /boot/loader.conf > digest && md5 -c $(cut -f2 -d= digest) /boot/loader.conf
181 MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6
184 Same as above but comparing the digest against an invalid string
185 .Pq Dq randomstring ,
186 which results in a failure.
187 .Bd -literal -offset indent
188 $ md5 -c randomstring /boot/loader.conf
189 MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6 [ Failed ]
192 If invoked with a name ending in
196 option does not compare against a hash string passed as parameter.
197 Instead, it expects a digest file, as created under the name
200 .Pa /boot/loader.conf
201 in the example above.
202 .Bd -literal -offset indent
203 $ md5 -c digest /boot/loader.conf
204 /boot/loader.conf: OK
207 The digest file may contain any number of lines in the format generated with or without the
210 .Pq i.e. in either classical BSD format or in GNU coreutils format .
211 If a hash value does not match the file, FAILED is printed instead of OK.
223 .%T The MD5 Message-Digest Algorithm
228 .%T The Secure Hash Standard
232 .%A D. Eastlake and P. Jones
233 .%T US Secure Hash Algorithm 1
237 RIPEMD-160 is part of the ISO draft standard
238 .Qq ISO/IEC DIS 10118-3
239 on dedicated hash functions.
241 Secure Hash Standard (SHS):
242 .Pa http://csrc.nist.gov/cryptval/shs.html .
245 .Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
247 All of the utilities that end in
249 are intended to be compatible with the GNU coreutils programs.
250 However, the long option functionality is not provided.
252 This program is placed in the public domain for free general use by
255 Support for SHA-1 and RIPEMD-160 has been added by
256 .An Oliver Eikemeier Aq Mt eik@FreeBSD.org .