pserv/src/jwt_demo_hs256.c
Godmar Back f6389fb4b6 changed header parsing to avoid cutting up space-contained values
- also fixes and updates to JWT examples
2021-04-23 13:16:31 -04:00

74 lines
1.7 KiB
C

/*
* Quick demo of how to use libjwt using a HS256.
*
* @author gback, CS 3214, Spring 2018, updated Spring 2021
*/
#include <jwt.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <errno.h>
static const char * NEVER_EMBED_A_SECRET_IN_CODE = "supa secret";
static void
die(const char *msg, int error)
{
fprintf(stderr, "%s: %s\n", msg, strerror(error));
exit(EXIT_FAILURE);
}
int
main()
{
jwt_t *mytoken;
int rc = jwt_new(&mytoken);
if (rc)
die("jwt_new", rc);
rc = jwt_add_grant(mytoken, "sub", "user0");
if (rc)
die("jwt_add_grant sub", rc);
time_t now = time(NULL);
rc = jwt_add_grant_int(mytoken, "iat", now);
if (rc)
die("jwt_add_grant iat", rc);
rc = jwt_add_grant_int(mytoken, "exp", now + 3600 * 24);
if (rc)
die("jwt_add_grant exp", rc);
rc = jwt_set_alg(mytoken, JWT_ALG_HS256,
(unsigned char *)NEVER_EMBED_A_SECRET_IN_CODE,
strlen(NEVER_EMBED_A_SECRET_IN_CODE));
if (rc)
die("jwt_set_alg", rc);
printf("dump:\n");
rc = jwt_dump_fp(mytoken, stdout, 1);
if (rc)
die("jwt_dump_fp", rc);
char *encoded = jwt_encode_str(mytoken);
if (encoded == NULL)
die("jwt_encode_str", ENOMEM);
printf("encoded as %s\nTry entering this at jwt.io\n", encoded);
jwt_t *ymtoken;
rc = jwt_decode(&ymtoken, encoded,
(unsigned char *)NEVER_EMBED_A_SECRET_IN_CODE,
strlen(NEVER_EMBED_A_SECRET_IN_CODE));
if (rc)
die("jwt_decode", rc);
char *grants = jwt_get_grants_json(ymtoken, NULL); // NULL means all
if (grants == NULL)
die("jwt_get_grants_json", ENOMEM);
printf("redecoded: %s\n", grants);
}