TeaSpeak/tomcrypt
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

moar doc

Browse Source 
[skip ci]
This commit is contained in:
Steffen Jaeckel 2017-08-09 15:56:13 +02:00
parent dd01232bcb
commit fc65352261
1 changed files with 45 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
doc/crypt.tex
View File

@ -2546,9 +2546,17 @@ for all purposes you would normally use a hash for.
\chapter{Checksum Functions} \chapter{Checksum Functions}
\mysection{CRC32 -- Cyclic redundancy check} \mysection{Preface}
XXX-TODO see \url{https://en.wikipedia.org/wiki/Cyclic_redundancy_check} The API for all checksum functions operate in mode: \textit{init} -- \textit{update} -- \textit{update} -- ... -- \textit{finish}.
The \textit{finish} functions allow to output a partial result if necessary.
\mysection{CRC-32 -- Cyclic redundancy check}
A Cyclic Redundancy Check is an error-detecting code, where LibTomCrypt implements CRC-32 with the polynomial \textit{0x04C11DB7}.
For further information see \url{https://en.wikipedia.org/wiki/Cyclic_redundancy_check}
\begin{verbatim} \begin{verbatim}
void crc32_init(crc32_state *ctx); void crc32_init(crc32_state *ctx);
@ -2556,9 +2564,11 @@ void crc32_update(crc32_state *ctx, const unsigned char *input, unsigned long le
void crc32_finish(crc32_state *ctx, void *hash, unsigned long size); void crc32_finish(crc32_state *ctx, void *hash, unsigned long size);
\end{verbatim} \end{verbatim}
\mysection{Adler32} \mysection{Adler-32}
XXX-TODO see \url{https://en.wikipedia.org/wiki/Adler-32} Adler-32 is a checksum algorithm.
For further information see \url{https://en.wikipedia.org/wiki/Adler-32}.
\begin{verbatim} \begin{verbatim}
void adler32_init(adler32_state *ctx); void adler32_init(adler32_state *ctx);
@ -5763,8 +5773,17 @@ At this point, we are pointing to the last node of the list. Lists are terminat
can walk up and down the nodes without keeping pointers lying around. can walk up and down the nodes without keeping pointers lying around.
\subsubsection{Shrink'ing a Flexi List}
While decoding the flexi decoder will recursively decode an ASN.1 \textit{constructed} type it will store the decoded list
as well as the plain data that was decoded.
To free up this additional data a shrink function is provided.
\index{der\_sequence\_shrink()}
\begin{verbatim}
void der_sequence_shrink(ltc_asn1_list *in);
\end{verbatim}
This will free all the plain constructed data, but keep the decoded list intact.
\subsubsection{Free'ing a Flexi List} \subsubsection{Free'ing a Flexi List}
To free the list use the following function. To free the list use the following function.
@ -6084,6 +6103,28 @@ int rand_bn_upto( void *N,
This ensures that \textit{N} is set to a random MPI in the range $1 \le N < limit$. This ensures that \textit{N} is set to a random MPI in the range $1 \le N < limit$.
\mysection{Helper functions}
\subsection{Zero'ing data}
XXX-TODO
\index{zeromem()}
\begin{verbatim}
void zeromem(volatile void *out, size_t outlen);
\end{verbatim}
\subsection{Constant-time memory compare}
XXX-TODO
\index{mem\_neq()}
\begin{verbatim}
int mem_neq(const void *a, const void *b, size_t len);
\end{verbatim}
\mysection{Dynamic Language Support} \mysection{Dynamic Language Support}
\index{Dynamic Language Support} \index{Dynamic Language Support}
Various LibTomCrypt functions require that their callers define a struct Various LibTomCrypt functions require that their callers define a struct