1md5(n) MD5 Message-Digest Algorithm md5(n)
2______________________________________________________________________________
6
8 md5 - MD5 Message-Digest Algorithm
9
11 package require Tcl 8.2
12 package require md5 ?2.0.7?
14 ::md5::md5 ?-hex? [ -channel channel | -file filename | string ]
16 ::md5::hmac ?-hex? -key key [ -channel channel | -file filename |
18 string ]
19 ::md5::MD5Init
21 ::md5::MD5Update token data
23 ::md5::MD5Final token
25 ::md5::HMACInit key
27 ::md5::HMACUpdate token data
29 ::md5::HMACFinal token
31_________________________________________________________________
33
35 This package is an implementation in Tcl of the MD5 message-digest
36 algorithm as described in RFC 1321 (1). This algorithm takes an arbi‐
37 trary quantity of data and generates a 128-bit message digest from the
38 input. The MD5 algorithm is related to the MD4 algorithm (2) but has
39 been strengthened against certain types of potential attack. MD5 should
40 be used in preference to MD4 for new applications.
41 If you have critcl and have built the tcllibc package then the imple‐
43 mentation of the hashing function will be performed by compiled code.
44 Alternatively if you have either cryptkit or Trf then either of these
45 can be used to accelerate the digest computation. If no suitable com‐
46 piled package is available then the pure-Tcl implementation wil be
47 used. The programming interface remains the same in all cases.
48 Note the previous version of this package always returned a hex encoded
50 string. This has been changed to simplify the programming interface and
51 to make this version more compatible with other implementations. To
52 obtain the previous usage, either explicitly specify package version 1
53 or use the -hex option to the md5 command.
54
56 ::md5::md5 ?-hex? [ -channel channel | -file filename | string ]
57 Calculate the MD5 digest of the data given in string. This is
58 returned as a binary string by default. Giving the -hex option
59 will return a hexadecimal encoded version of the digest.
60 The data to be hashed can be specified either as a string argu‐
62 ment to the md5 command, or as a filename or a pre-opened chan‐
63 nel. If the -filename argument is given then the file is opened,
64 the data read and hashed and the file is closed. If the -channel
65 argument is given then data is read from the channel until the
66 end of file. The channel is not closed.
67 Only one of -file, -channel or string should be given.
69 ::md5::hmac ?-hex? -key key [ -channel channel | -file filename |
71 string ]
72 Calculate an Hashed Message Authentication digest (HMAC) using
73 the MD5 digest algorithm. HMACs are described in RFC 2104 (3)
74 and provide an MD5 digest that includes a key. All options other
75 than -key are as for the ::md5::md5 command.
76
78 For the programmer, the MD5 hash can be viewed as a bucket into which
79 one pours data. When you have finished, you extract a value that is
80 derived from the data that was poured into the bucket. The programming
81 interface to the MD5 hash operates on a token (equivalent to the
82 bucket). You call MD5Init to obtain a token and then call MD5Update as
83 many times as required to add data to the hash. To release any
84 resources and obtain the hash value, you then call MD5Final. An equiva‐
85 lent set of functions gives you a keyed digest (HMAC).
86 ::md5::MD5Init
88 Begins a new MD5 hash. Returns a token ID that must be used for
89 the remaining functions.
90 ::md5::MD5Update token data
92 Add data to the hash identified by token. Calling MD5Update
93 $token "abcd" is equivalent to calling MD5Update $token "ab"
94 followed by MD5Update $token "cb". See EXAMPLES.
95 ::md5::MD5Final token
97 Returns the hash value and releases any resources held by this
98 token. Once this command completes the token will be invalid.
99 The result is a binary string of 16 bytes representing the 128
100 bit MD5 digest value.
101 ::md5::HMACInit key
103 This is equivalent to the ::md5::MD5Init command except that it
104 requires the key that will be included in the HMAC.
105 ::md5::HMACUpdate token data
107 ::md5::HMACFinal token
109 These commands are identical to the MD5 equivalent commands.
110
112 % md5::md5 -hex "Tcl does MD5"
113 8AAC1EE01E20BB347104FABB90310433
114 % md5::hmac -hex -key Sekret "Tcl does MD5"
117 35BBA244FD56D3EDF5F3C47474DACB5D
118 % set tok [md5::MD5Init]
121 ::md5::1
122 % md5::MD5Update $tok "Tcl "
123 % md5::MD5Update $tok "does "
124 % md5::MD5Update $tok "MD5"
125 % md5::Hex [md5::MD5Final $tok]
126 8AAC1EE01E20BB347104FABB90310433
127
130 [1] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, MIT
131 and RSA Data Security, Inc, April 1992. (http://www.rfc-edi‐
132 tor.org/rfc/rfc1321.txt)
133 [2] Rivest, R., "The MD4 Message Digest Algorithm", RFC 1320, MIT,
135 April 1992. (http://www.rfc-editor.org/rfc/rfc1320.txt)
136 [3] Krawczyk, H., Bellare, M. and Canetti, R. "HMAC: Keyed-Hashing
138 for Message Authentication", RFC 2104, February 1997.
139 (http://www.rfc-editor.org/rfc/rfc2104.txt)
140
142 This document, and the package it describes, will undoubtedly contain
143 bugs and other problems. Please report such in the category md5 of the
144 Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883].
145 Please also report any ideas for enhancements you may have for either
146 package and/or documentation.
147
149 md4, sha1
150
152 hashing, md5, message-digest, rfc 1320, rfc 1321, rfc 2104, security
153
155 Copyright (c) 2003, Pat Thoyts <patthoyts@users.sourceforge.net>
156md5 2.0.7 md5(n)