| \section{\module{md5} --- |
| MD5 message digest algorithm} |
| |
| \declaremodule{builtin}{md5} |
| \modulesynopsis{RSA's MD5 message digest algorithm.} |
| |
| |
| This module implements the interface to RSA's MD5 message digest |
| \index{message digest, MD5} |
| algorithm (see also Internet \rfc{1321}). Its use is quite |
| straightforward:\ use the \function{new()} to create an md5 object. |
| You can now feed this object with arbitrary strings using the |
| \method{update()} method, and at any point you can ask it for the |
| \dfn{digest} (a strong kind of 128-bit checksum, |
| a.k.a. ``fingerprint'') of the concatenation of the strings fed to it |
| so far using the \method{digest()} method. |
| \index{checksum!MD5} |
| |
| For example, to obtain the digest of the string \code{'Nobody inspects |
| the spammish repetition'}: |
| |
| \begin{verbatim} |
| >>> import md5 |
| >>> m = md5.new() |
| >>> m.update("Nobody inspects") |
| >>> m.update(" the spammish repetition") |
| >>> m.digest() |
| '\273d\234\203\335\036\245\311\331\336\311\241\215\360\377\351' |
| \end{verbatim} |
| |
| More condensed: |
| |
| \begin{verbatim} |
| >>> md5.new("Nobody inspects the spammish repetition").digest() |
| '\273d\234\203\335\036\245\311\331\336\311\241\215\360\377\351' |
| \end{verbatim} |
| |
| \begin{funcdesc}{new}{\optional{arg}} |
| Return a new md5 object. If \var{arg} is present, the method call |
| \code{update(\var{arg})} is made. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{md5}{\optional{arg}} |
| For backward compatibility reasons, this is an alternative name for the |
| \function{new()} function. |
| \end{funcdesc} |
| |
| An md5 object has the following methods: |
| |
| \begin{methoddesc}[md5]{update}{arg} |
| Update the md5 object with the string \var{arg}. Repeated calls are |
| equivalent to a single call with the concatenation of all the |
| arguments, i.e.\ \code{m.update(a); m.update(b)} is equivalent to |
| \code{m.update(a+b)}. |
| \end{methoddesc} |
| |
| \begin{methoddesc}[md5]{digest}{} |
| Return the digest of the strings passed to the \method{update()} |
| method so far. This is an 16-byte string which may contain |
| non-\ASCII{} characters, including null bytes. |
| \end{methoddesc} |
| |
| \begin{methoddesc}[md5]{copy}{} |
| Return a copy (``clone'') of the md5 object. This can be used to |
| efficiently compute the digests of strings that share a common initial |
| substring. |
| \end{methoddesc} |