md5(n) MD5 Message-Digest Algorithm md5(n) 







md5 - MD5 Message-Digest Algorithm








package require Tcl 8.2


package require md5 ?2.0.7?


::md5::md5 ?-hex? [ -channel channel |
    -file filename | string ]


::md5::hmac ?-hex? -key key [ -channel
    channel | -file filename | string ]


::md5::MD5Init


::md5::MD5Update token data


::md5::MD5Final token


::md5::HMACInit key


::md5::HMACUpdate token data


::md5::HMACFinal token












This package is an implementation in Tcl of the MD5 message-digest
    algorithm as described in RFC 1321 (1). This algorithm takes an arbitrary
    quantity of data and generates a 128-bit message digest from the input. The
    MD5 algorithm is related to the MD4 algorithm (2) but has been strengthened
    against certain types of potential attack. MD5 should be used in preference
    to MD4 for new applications.


If you have critcl and have built the tcllibc
    package then the implementation of the hashing function will be performed by
    compiled code. Alternatively if you have either cryptkit or
    Trf then either of these can be used to accelerate the digest
    computation. If no suitable compiled package is available then the pure-Tcl
    implementation wil be used. The programming interface remains the same in
    all cases.


Note the previous version of this package always returned a
    hex encoded string. This has been changed to simplify the programming
    interface and to make this version more compatible with other
    implementations. To obtain the previous usage, either explicitly specify
    package version 1 or use the -hex option to the md5
  command.









  
::md5::md5 ?-hex? [ -channel channel | -file
    filename | string ]

  
Calculate the MD5 digest of the data given in string. This is returned as
      a binary string by default. Giving the -hex option will return a
      hexadecimal encoded version of the digest.
    
The data to be hashed can be specified either as a string
        argument to the md5 command, or as a filename or a pre-opened
        channel. If the -filename argument is given then the file is
        opened, the data read and hashed and the file is closed. If the
        -channel argument is given then data is read from the channel
        until the end of file. The channel is not closed.

    
Only one of -file, -channel or string
        should be given.

  

  
::md5::hmac ?-hex? -key key [ -channel channel
    | -file filename | string ]

  
Calculate an Hashed Message Authentication digest (HMAC) using the MD5
      digest algorithm. HMACs are described in RFC 2104 (3) and provide an MD5
      digest that includes a key. All options other than -key are as for
      the ::md5::md5 command.










For the programmer, the MD5 hash can be viewed as a bucket into
    which one pours data. When you have finished, you extract a value that is
    derived from the data that was poured into the bucket. The programming
    interface to the MD5 hash operates on a token (equivalent to the bucket).
    You call MD5Init to obtain a token and then call MD5Update as
    many times as required to add data to the hash. To release any resources and
    obtain the hash value, you then call MD5Final. An equivalent set of
    functions gives you a keyed digest (HMAC).



  
::md5::MD5Init

  
Begins a new MD5 hash. Returns a token ID that must be used for the
      remaining functions.

  
::md5::MD5Update token data

  
Add data to the hash identified by token. Calling MD5Update $token
      "abcd" is equivalent to calling MD5Update $token
      "ab" followed by MD5Update $token "cb". See
      EXAMPLES.

  
::md5::MD5Final token

  
Returns the hash value and releases any resources held by this token. Once
      this command completes the token will be invalid. The result is a binary
      string of 16 bytes representing the 128 bit MD5 digest value.

  
::md5::HMACInit key

  
This is equivalent to the ::md5::MD5Init command except that it
      requires the key that will be included in the HMAC.

  
::md5::HMACUpdate token data

  

  
::md5::HMACFinal token

  
These commands are identical to the MD5 equivalent commands.










% md5::md5 -hex "Tcl does MD5"
8AAC1EE01E20BB347104FABB90310433



% md5::hmac -hex -key Sekret "Tcl does MD5"
35BBA244FD56D3EDF5F3C47474DACB5D



% set tok [md5::MD5Init]
::md5::1
% md5::MD5Update $tok "Tcl "
% md5::MD5Update $tok "does "
% md5::MD5Update $tok "MD5"
% md5::Hex [md5::MD5Final $tok]
8AAC1EE01E20BB347104FABB90310433










  
[1]

  
Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, MIT
      and RSA Data Security, Inc, April 1992.
      (http://www.rfc-editor.org/rfc/rfc1321.txt)

  
[2]

  
Rivest, R., "The MD4 Message Digest Algorithm", RFC 1320, MIT,
      April 1992. (http://www.rfc-editor.org/rfc/rfc1320.txt)

  
[3]

  
Krawczyk, H., Bellare, M. and Canetti, R. "HMAC: Keyed-Hashing for
      Message Authentication", RFC 2104, February 1997.
      (http://www.rfc-editor.org/rfc/rfc2104.txt)










This document, and the package it describes, will undoubtedly
    contain bugs and other problems. Please report such in the category
    md5 of the Tcllib SF Trackers
    [http://sourceforge.net/tracker/?group_id=12883]. Please also report any
    ideas for enhancements you may have for either package and/or
  documentation.








md4, sha1








hashing, md5, message-digest, rfc 1320, rfc 1321, rfc 2104,
    security








Hashes, checksums, and encryption








Copyright (c) 2003, Pat Thoyts <patthoyts@users.sourceforge.net>








  

    2.0.7
    md5