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A new hashlib module to replace the md5 and sha modules. It adds support for additional secure hashes such as SHA-256 and SHA-512. The hashlib module uses OpenSSL for fast platform optimized implementations of algorithms when available. The old md5 and sha modules still exist as wrappers around hashlib to preserve backwards compatibility.
54 lines
2.1 KiB
TeX
54 lines
2.1 KiB
TeX
\section{\module{hmac} ---
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Keyed-Hashing for Message Authentication}
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\declaremodule{standard}{hmac}
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\modulesynopsis{Keyed-Hashing for Message Authentication (HMAC)
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implementation for Python.}
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\moduleauthor{Gerhard H{\"a}ring}{ghaering@users.sourceforge.net}
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\sectionauthor{Gerhard H{\"a}ring}{ghaering@users.sourceforge.net}
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\versionadded{2.2}
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This module implements the HMAC algorithm as described by \rfc{2104}.
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\begin{funcdesc}{new}{key\optional{, msg\optional{, digestmod}}}
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Return a new hmac object. If \var{msg} is present, the method call
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\code{update(\var{msg})} is made. \var{digestmod} is the digest
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constructor or module for the HMAC object to use. It defaults to
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the \code{\refmodule{hashlib}.md5} constructor. \note{The md5 hash
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has known weaknesses but remains the default for backwards compatibility.
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Choose a better one for your application.}
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\end{funcdesc}
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An HMAC object has the following methods:
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\begin{methoddesc}[hmac]{update}{msg}
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Update the hmac object with the string \var{msg}. Repeated calls
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are equivalent to a single call with the concatenation of all the
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arguments: \code{m.update(a); m.update(b)} is equivalent to
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\code{m.update(a + b)}.
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\end{methoddesc}
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\begin{methoddesc}[hmac]{digest}{}
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Return the digest of the strings passed to the \method{update()}
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method so far. This string will be the same length as the
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\var{digest_size} of the digest given to the constructor. It
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may contain non-\ASCII{} characters, including NUL bytes.
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\end{methoddesc}
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\begin{methoddesc}[hmac]{hexdigest}{}
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Like \method{digest()} except the digest is returned as a string
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twice the length containing
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only hexadecimal digits. This may be used to exchange the value
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safely in email or other non-binary environments.
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\end{methoddesc}
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\begin{methoddesc}[hmac]{copy}{}
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Return a copy (``clone'') of the hmac object. This can be used to
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efficiently compute the digests of strings that share a common
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initial substring.
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\end{methoddesc}
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\begin{seealso}
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\seemodule{hashlib}{The python module providing secure hash functions.}
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\end{seealso}
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