add hg and python

1 files changed, 83 insertions, 0 deletions

diff --git a/sys/src/cmd/python/Doc/lib/libsha.tex b/sys/src/cmd/python/Doc/lib/libsha.tex
new file mode 100644
index 000000000..6d1da68da
--- /dev/null
+++ b/sys/src/cmd/python/Doc/lib/libsha.tex
@@ -0,0 +1,83 @@
+\section{\module{sha} ---
+         SHA-1 message digest algorithm}
+
+\declaremodule{builtin}{sha}
+\modulesynopsis{NIST's secure hash algorithm, SHA.}
+\sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
+
+\deprecated{2.5}{Use the \refmodule{hashlib} module instead.}
+
+
+This module implements the interface to NIST's\index{NIST} secure hash 
+algorithm,\index{Secure Hash Algorithm} known as SHA-1.  SHA-1 is an
+improved version of the original SHA hash algorithm.  It is used in
+the same way as the \refmodule{md5} module:\ use \function{new()}
+to create an sha object, then feed this object with arbitrary strings
+using the \method{update()} method, and at any point you can ask it
+for the \dfn{digest} of the concatenation of the strings fed to it
+so far.\index{checksum!SHA}  SHA-1 digests are 160 bits instead of
+MD5's 128 bits.
+
+
+\begin{funcdesc}{new}{\optional{string}}
+  Return a new sha object.  If \var{string} is present, the method
+  call \code{update(\var{string})} is made.
+\end{funcdesc}
+
+
+The following values are provided as constants in the module and as
+attributes of the sha objects returned by \function{new()}:
+
+\begin{datadesc}{blocksize}
+  Size of the blocks fed into the hash function; this is always
+  \code{1}.  This size is used to allow an arbitrary string to be
+  hashed.
+\end{datadesc}
+
+\begin{datadesc}{digest_size}
+  The size of the resulting digest in bytes.  This is always
+  \code{20}.
+\end{datadesc}
+
+
+An sha object has the same methods as md5 objects:
+
+\begin{methoddesc}[sha]{update}{arg}
+Update the sha object with the string \var{arg}.  Repeated calls are
+equivalent to a single call with the concatenation of all the
+arguments: \code{m.update(a); m.update(b)} is equivalent to
+\code{m.update(a+b)}.
+\end{methoddesc}
+
+\begin{methoddesc}[sha]{digest}{}
+Return the digest of the strings passed to the \method{update()}
+method so far.  This is a 20-byte string which may contain
+non-\ASCII{} characters, including null bytes.
+\end{methoddesc}
+
+\begin{methoddesc}[sha]{hexdigest}{}
+Like \method{digest()} except the digest is returned as a string of
+length 40, containing only hexadecimal digits.  This may 
+be used to exchange the value safely in email or other non-binary
+environments.
+\end{methoddesc}
+
+\begin{methoddesc}[sha]{copy}{}
+Return a copy (``clone'') of the sha object.  This can be used to
+efficiently compute the digests of strings that share a common initial
+substring.
+\end{methoddesc}
+
+\begin{seealso}
+  \seetitle[http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf]
+    {Secure Hash Standard}
+    {The Secure Hash Algorithm is defined by NIST document FIPS
+     PUB 180-2:
+     \citetitle[http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf]
+        {Secure Hash Standard}, published in August 2002.}
+
+  \seetitle[http://csrc.nist.gov/encryption/tkhash.html]
+           {Cryptographic Toolkit (Secure Hashing)}
+           {Links from NIST to various information on secure hashing.}
+\end{seealso}
+