mirror of
https://git.FreeBSD.org/ports.git
synced 2024-10-31 21:57:12 +00:00
41 lines
2.1 KiB
Plaintext
41 lines
2.1 KiB
Plaintext
The MD5 module allows you to use the RSA Data Security
|
|
Inc. MD5 Message Digest algorithm from within Perl
|
|
programs.
|
|
|
|
A new MD5 context object is created with the new
|
|
operation. Multiple simultaneous digest contexts can be
|
|
maintained, if desired. The context is updated with the
|
|
add operation which adds the strings contained in the LIST
|
|
parameter. Note, however, that add('foo', 'bar'),
|
|
add('foo') followed by add('bar') and add('foobar') should
|
|
all give the same result.
|
|
|
|
The final message digest value is returned by the digest
|
|
operation as a 16-byte binary string. This operation
|
|
delivers the result of add operations since the last new
|
|
or reset operation. Note that the digest operation is
|
|
effectively a destructive, read-once operation. Once it
|
|
has been performed, the context must be reset before being
|
|
used to calculate another digest value.
|
|
|
|
Several convenience functions are also provided. The
|
|
addfile operation takes an open file-handle and reads it
|
|
until end-of file in 1024 byte blocks adding the contents
|
|
to the context. The file-handle can either be specified by
|
|
name or passed as a type-glob reference, as shown in the
|
|
examples below. The hexdigest operation calls digest and
|
|
returns the result as a printable string of hexdecimal
|
|
digits. This is exactly the same operation as performed by
|
|
the unpack operation in the examples below.
|
|
|
|
The hash operation can act as either a static member
|
|
function (ie you invoke it on the MD5 class as in the
|
|
synopsis above) or as a normal virtual function. In both
|
|
cases it performs the complete MD5 cycle (reset, add,
|
|
digest) on the supplied scalar value. This is convenient
|
|
for handling small quantities of data. When invoked on the
|
|
class a temporary context is created. When invoked through
|
|
an already created context object, this context is used.
|
|
The latter form is slightly more efficient. The hexhash
|
|
operation is analogous to hexdigest.
|