mmo-ref/dep-libtomcrypt
1
0
Fork 0
mirror of https://github.com/libtom/libtomcrypt synced 2026-08-25 20:26:07 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Update docs

Browse source 
Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>
This commit is contained in:
Steffen Jaeckel 2024-02-26 11:21:12 +01:00
parent d11758e700
commit 8be96ac2f6
1 changed files with 65 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

67
doc/crypt.tex
View file

@ -2877,6 +2877,7 @@ For further information see \url{https://en.wikipedia.org/wiki/SHA-3}
Example of using SHAKE256 with an arbitrary length output.
\begin{small}
\begin{verbatim}
#include <tomcrypt.h>
int main(void)
@ -2901,14 +2902,76 @@ int main(void)
return EXIT_SUCCESS;
}
\end{verbatim}
\end{small}
\mysection{Extended Tiger API}
The Tiger and Tiger2 hash algorithms \url{http://www.cs.technion.ac.il/~biham/Reports/Tiger/} specify the possibility to run the algorithm with
a configurable number of passes. The default and minimum is 3 passes, there is a second more or less widely used version with 4 passes,
which has been introduced by PHP. Its utilization is mostly limited to PHP, so we don't provide descriptors by default.
An example of how to use the 4-pass version of Tiger in a libtomcrypt-style way is shown below.
\index{tiger\_init\_ex()}
\begin{small}
\begin{verbatim}
#include <tomcrypt.h>
static const char *tiger_4passes_name = "tiger-4passes";
static int tiger_4passes_init(hash_state *md)
{
return tiger_init_ex(md, 4);
}
static struct ltc_hash_descriptor tiger_4passes_desc;
int main(void)
{
int err = 0;
unsigned char hash[MAXBLOCKSIZE], *p;
unsigned long hashlen = sizeof(hash);
memcpy(&tiger_4passes_desc, &tiger_desc, sizeof(tiger_4passes_desc));
tiger_4passes_desc.init = tiger_4passes_init;
/* Make sure to have a different name, ID and OID than standard Tiger */
tiger_4passes_desc.name = tiger_4passes_name;
tiger_4passes_desc.ID |= 0x80u;
memset(tiger_4passes_desc.OID, 0, sizeof(tiger_4passes_desc.OID));
tiger_4passes_desc.OIDlen = 0;
if ((err = register_hash(&tiger_4passes_desc)) == CRYPT_OK) {
err = hash_memory(find_hash(tiger_4passes_name), (unsigned char*)"abc", 3, hash, &hashlen);
}
if (err != 0) {
fprintf(stderr, "Error %s (%d)", error_to_string(err), err);
} else {
p = hash;
printf("Resulting hash: ");
while(hashlen--) {
printf("%02x", *p++);
}
printf("\n");
}
return err;
}
\end{verbatim}
\end{small}
When compiling and running this, the output should be:
\begin{verbatim}
Resulting hash: 538883c8fc5f28250299018e66bdf4fdb5ef7b65f2e91753
\end{verbatim}
\mysection{Notice}
It is highly recommended that you \textbf{not} use the MD2, MD4, MD5, or SHA-1 hashes for the purposes of digital signatures or authentication codes.
These hashes are provided for completeness and they still can be used for the purposes of password hashing or one-way accumulators
(e.g. Yarrow).
The other hashes such as the SHA-2 (that includes SHA-512, SHA-512/384, SHA-384, SHA-512/256, SHA-256 and SHA-224) and TIGER-192 are still considered secure
for all purposes you would normally use a hash for.
The other hashes such as the SHA-2 (that includes SHA-512, SHA-512/384, SHA-384, SHA-512/256, SHA-256 and SHA-224), TIGER-192 and TIGER2-192 are still
considered secure for all purposes you would normally use a hash for.
\chapter{Checksum Functions}