libsodium/demos/onetimeauth.c

72 lines
1.8 KiB
C

/*
* GraxRabble
* 05 May 2014
* Demo programs for libsodium.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sodium.h> /* library header */
#include "demo_utils.h" /* utility functions shared by demos */
/*
* This method is only effective for a single use per key. The benefit is
* the algorithm is quicker and output is half the size of auth. It is easy
* to see how weak the algorithm is when you use a one letter key.
*
* Note that the same key must not be used more than once.
*/
static int
onetimeauth(void)
{
unsigned char k[crypto_onetimeauth_KEYBYTES];/* key */
unsigned char a[crypto_onetimeauth_BYTES]; /* authentication */
unsigned char m[BUFFER_SIZE]; /* message */
size_t mlen; /* message length */
int r;
sodium_memzero(k, sizeof k); /* must zero the key */
puts("Example: crypto_onetimeauth\n");
prompt_input("Input your key > ", (char*) k, sizeof k);
mlen = prompt_input("Input your message > ", (char*) m, sizeof m);
putchar('\n');
printf("Generating %s authentication...\n",
crypto_onetimeauth_primitive());
crypto_onetimeauth(a, m, mlen, k);
puts("Format: authentication token::message");
print_hex(a, sizeof a);
fputs("::", stdout);
puts((const char*) m);
putchar('\n');
puts("Verifying authentication...");
r = crypto_onetimeauth_verify(a, m, mlen, k);
print_verification(r);
sodium_memzero(k, sizeof k); /* wipe sensitive data */
sodium_memzero(a, sizeof a);
sodium_memzero(m, sizeof m);
return r;
}
int
main(int argc, char **argv)
{
int r;
sodium_init();
printf("Using LibSodium %s\n", sodium_version_string());
r = (0 == onetimeauth() ? EXIT_SUCCESS : EXIT_FAILURE);
exit(r);
}