Re: checksum with ruby, how?

"shasckaw" wrote:

> >> ... digest/md5 .... but I can't find any
> >>documentation about how to use it (searched on ruby-doc and RAA)


For the archive (and the 'doc. squad') --

This is in the source distribution:
     (ext/digest/digest.txt)

                          Can it be made more visible ?
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** MD5(Class)

A class to implement the MD5 Message-Digest Algorithm by RSA Data
Security, Inc., described in RFC1321.

Superclass: Digest::Base

require 'digest/md5'

** SHA1(Class)

A class to implement the SHA-1 Secure Hash Algorithm by NIST (the US'
National Institute of Standards and Technology), described in FIPS PUB
180-1.

Superclass: Digest::Base

require 'digest/sha1'

** SHA256(Class)
** SHA384(Class)
** SHA512(Class)

Classes to implement the SHA-256/384/512 Secure Hash Algorithm(s) by
NIST (the US' National Institute of Standards and Technology),
described in FIPS PUB 180-2.

Superclass: Digest::Base

require 'digest/sha2'

** RMD160(Class)

A class to implement the RIPEMD-160 cryptographic hash function,
designed by Hans Dobbertin, Antoon Bosselaers, and Bart Preneel.

Superclass: Digest::Base

require 'digest/rmd160'


Those above classes provide a common interface as shown below.


Class Methods:

   new([str])

 Creates a new digest object.  If a string argument is given,
 it is added to the object. (see update.)

   digest(str)

 Immediately calculates and return the hash of the given
 strings as a string.  Equivalent to new(str).digest.

   hexdigest(str)

 Immediately calculates and return the hash of the given
 strings as a string of hexadecimal digits.  Equivalent to
 new(str).hexdigest.

Methods:

   clone

 Creates a copy of the digest object.

   digest

 Returns the hash of the added strings as a string of 16 bytes
 for MD5, 20 bytes for SHA1 and RMD160, 32 bytes for SHA256, 48
 bytes for SHA384, and 64 bytes for SHA512.

   hexdigest
   to_s

 Returns the hash of the added strings as a string of 32
 hexadecimal digits for MD5, 40 hexadecimal digits for SHA1 and
 RMD160, 64 hexadecimal digits for SHA256, 96 hexadecimal
 digits for SHA384, and 128 hexadecimal digits for SHA512.
 This method is equal to:

 def hexdigest
   digest.unpack("H*")[0]
 end

   update(str)
   << str

 Appends the string str to the digest object.  Repeated calls
 are equivalent to a single call with the concatenation of all
 the arguments, i.e. m.update(a); m.update(b) is equivalent to
 m.update(a + b) and m << a << b is equivalent to m << a + b.

   == md

 Checks if the object is equal to the given digest object.

   == str

 Regards the value as either a digest value or a hexdigest
 value (depending on the length) and checks if the object is
 equal to the given string.

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