2.Dd June 6, 2004
3.Dt MD5 1
4.Os
5.Sh NAME
6.Nm md5 , sha1 , rmd160
7.Nd calculate a message-digest fingerprint (checksum) for a file
8.Sh SYNOPSIS
9.Nm md5
10.Op Fl pqrtx
11.Op Fl s Ar string
12.Op Ar
13.Nm sha1
14.Op Fl pqrtx
15.Op Fl s Ar string
16.Op Ar
17.Nm rmd160
18.Op Fl pqrtx
19.Op Fl s Ar string
20.Op Ar
21.Sh DESCRIPTION
| 2.Dd June 6, 2004
3.Dt MD5 1
4.Os
5.Sh NAME
6.Nm md5 , sha1 , rmd160
7.Nd calculate a message-digest fingerprint (checksum) for a file
8.Sh SYNOPSIS
9.Nm md5
10.Op Fl pqrtx
11.Op Fl s Ar string
12.Op Ar
13.Nm sha1
14.Op Fl pqrtx
15.Op Fl s Ar string
16.Op Ar
17.Nm rmd160
18.Op Fl pqrtx
19.Op Fl s Ar string
20.Op Ar
21.Sh DESCRIPTION
|
23.Nm md5 , sha1
24and
25.Nm rmd160
26utilities take as input a message of arbitrary length and produce as
27output a
28.Dq fingerprint
29or
30.Dq message digest
31of the input.
32It is conjectured that it is computationally infeasible to
33produce two messages having the same message digest, or to produce any
34message having a given prespecified target message digest.
35The
36.Tn MD5 , SHA-1
37and
38.Tn RIPEMD-160
39algorithms are intended for digital signature applications, where a
40large file must be
41.Dq compressed
42in a secure manner before being encrypted with a private
43(secret)
44key under a public-key cryptosystem such as
45.Tn RSA .
46.Pp
47.Tn MD5
48has not yet (2001-09-03) been broken, but sufficient attacks have been
49made that its security is in some doubt.
50The attacks on
51.Tn MD5
52are in the nature of finding
53.Dq collisions
54\(em that is, multiple
55inputs which hash to the same value; it is still unlikely for an attacker
56to be able to determine the exact original input given a hash value.
57.Pp
58The following options may be used in any combination and must
59precede any files named on the command line.
60The hexadecimal checksum of each file listed on the command line is printed
61after the options are processed.
62.Bl -tag -width indent
63.It Fl s Ar string
64Print a checksum of the given
65.Ar string .
66.It Fl p
67Echo stdin to stdout and append the checksum to stdout.
68.It Fl q
69Quiet mode - only the checksum is printed out.
70Overrides the
71.Fl r
72option.
73.It Fl r
74Reverses the format of the output.
75This helps with visual diffs.
76Does nothing
77when combined with the
78.Fl ptx
79options.
80.It Fl t
81Run a built-in time trial.
82.It Fl x
83Run a built-in test script.
84.El
85.Sh DIAGNOSTICS
86The
87.Nm md5 , sha1
88and
89.Nm rmd160
90utilities exit 0 on success,
91and 1 if at least one of the input files could not be read.
92.Sh SEE ALSO
93.Xr cksum 1 ,
94.Xr md5 3 ,
95.Xr ripemd 3 ,
96.Xr sha 3
97.Rs
98.%A R. Rivest
99.%T The MD5 Message-Digest Algorithm
100.%O RFC1321
101.Re
102.Rs
103.%A J. Burrows
104.%T The Secure Hash Standard
105.%O FIPS PUB 180-1
106.Re
107.Rs
108.%A D. Eastlake and P. Jones
109.%T US Secure Hash Algorithm 1
110.%O RFC 3174
111.Re
112.Pp
113RIPEMD-160 is part of the ISO draft standard
114.Qq ISO/IEC DIS 10118-3
115on dedicated hash functions.
116.Pp
117Secure Hash Standard (SHS):
118.Pa http://csrc.nist.gov/cryptval/shs.html .
119.Pp
120The RIPEMD-160 page:
121.Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
122.Sh ACKNOWLEDGMENTS
123This program is placed in the public domain for free general use by
124RSA Data Security.
125.Pp
126Support for SHA-1 and RIPEMD-160 has been added by
127.An Oliver Eikemeier Aq eik@FreeBSD.org .
| 23.Nm md5 , sha1
24and
25.Nm rmd160
26utilities take as input a message of arbitrary length and produce as
27output a
28.Dq fingerprint
29or
30.Dq message digest
31of the input.
32It is conjectured that it is computationally infeasible to
33produce two messages having the same message digest, or to produce any
34message having a given prespecified target message digest.
35The
36.Tn MD5 , SHA-1
37and
38.Tn RIPEMD-160
39algorithms are intended for digital signature applications, where a
40large file must be
41.Dq compressed
42in a secure manner before being encrypted with a private
43(secret)
44key under a public-key cryptosystem such as
45.Tn RSA .
46.Pp
47.Tn MD5
48has not yet (2001-09-03) been broken, but sufficient attacks have been
49made that its security is in some doubt.
50The attacks on
51.Tn MD5
52are in the nature of finding
53.Dq collisions
54\(em that is, multiple
55inputs which hash to the same value; it is still unlikely for an attacker
56to be able to determine the exact original input given a hash value.
57.Pp
58The following options may be used in any combination and must
59precede any files named on the command line.
60The hexadecimal checksum of each file listed on the command line is printed
61after the options are processed.
62.Bl -tag -width indent
63.It Fl s Ar string
64Print a checksum of the given
65.Ar string .
66.It Fl p
67Echo stdin to stdout and append the checksum to stdout.
68.It Fl q
69Quiet mode - only the checksum is printed out.
70Overrides the
71.Fl r
72option.
73.It Fl r
74Reverses the format of the output.
75This helps with visual diffs.
76Does nothing
77when combined with the
78.Fl ptx
79options.
80.It Fl t
81Run a built-in time trial.
82.It Fl x
83Run a built-in test script.
84.El
85.Sh DIAGNOSTICS
86The
87.Nm md5 , sha1
88and
89.Nm rmd160
90utilities exit 0 on success,
91and 1 if at least one of the input files could not be read.
92.Sh SEE ALSO
93.Xr cksum 1 ,
94.Xr md5 3 ,
95.Xr ripemd 3 ,
96.Xr sha 3
97.Rs
98.%A R. Rivest
99.%T The MD5 Message-Digest Algorithm
100.%O RFC1321
101.Re
102.Rs
103.%A J. Burrows
104.%T The Secure Hash Standard
105.%O FIPS PUB 180-1
106.Re
107.Rs
108.%A D. Eastlake and P. Jones
109.%T US Secure Hash Algorithm 1
110.%O RFC 3174
111.Re
112.Pp
113RIPEMD-160 is part of the ISO draft standard
114.Qq ISO/IEC DIS 10118-3
115on dedicated hash functions.
116.Pp
117Secure Hash Standard (SHS):
118.Pa http://csrc.nist.gov/cryptval/shs.html .
119.Pp
120The RIPEMD-160 page:
121.Pa http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html .
122.Sh ACKNOWLEDGMENTS
123This program is placed in the public domain for free general use by
124RSA Data Security.
125.Pp
126Support for SHA-1 and RIPEMD-160 has been added by
127.An Oliver Eikemeier Aq eik@FreeBSD.org .
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