/usr/share/doc/gnutls-doc/examples/ex-client-psk.c is in gnutls-doc 3.5.18-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | /* This example code is placed in the public domain. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <assert.h>
#include <gnutls/gnutls.h>
/* A very basic TLS client, with PSK authentication.
*/
#define CHECK(x) assert((x)>=0)
#define MAX_BUF 1024
#define MSG "GET / HTTP/1.0\r\n\r\n"
extern int tcp_connect(void);
extern void tcp_close(int sd);
int main(void)
{
int ret, sd, ii;
gnutls_session_t session;
char buffer[MAX_BUF + 1];
const char *err;
gnutls_psk_client_credentials_t pskcred;
const gnutls_datum_t key = { (void *) "DEADBEEF", 8 };
CHECK(gnutls_global_init());
CHECK(gnutls_psk_allocate_client_credentials(&pskcred));
CHECK(gnutls_psk_set_client_credentials(pskcred, "test", &key,
GNUTLS_PSK_KEY_HEX));
/* Initialize TLS session
*/
CHECK(gnutls_init(&session, GNUTLS_CLIENT));
/* Use default priorities */
ret =
gnutls_priority_set_direct(session,
"PERFORMANCE:+ECDHE-PSK:+DHE-PSK:+PSK",
&err);
if (ret < 0) {
if (ret == GNUTLS_E_INVALID_REQUEST) {
fprintf(stderr, "Syntax error at: %s\n", err);
}
exit(1);
}
/* put the x509 credentials to the current session
*/
CHECK(gnutls_credentials_set(session, GNUTLS_CRD_PSK, pskcred));
/* connect to the peer
*/
sd = tcp_connect();
gnutls_transport_set_int(session, sd);
gnutls_handshake_set_timeout(session,
GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
/* Perform the TLS handshake
*/
do {
ret = gnutls_handshake(session);
}
while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
if (ret < 0) {
fprintf(stderr, "*** Handshake failed\n");
gnutls_perror(ret);
goto end;
} else {
char *desc;
desc = gnutls_session_get_desc(session);
printf("- Session info: %s\n", desc);
gnutls_free(desc);
}
CHECK(gnutls_record_send(session, MSG, strlen(MSG)));
ret = gnutls_record_recv(session, buffer, MAX_BUF);
if (ret == 0) {
printf("- Peer has closed the TLS connection\n");
goto end;
} else if (ret < 0 && gnutls_error_is_fatal(ret) == 0) {
fprintf(stderr, "*** Warning: %s\n", gnutls_strerror(ret));
} else if (ret < 0) {
fprintf(stderr, "*** Error: %s\n", gnutls_strerror(ret));
goto end;
}
if (ret > 0) {
printf("- Received %d bytes: ", ret);
for (ii = 0; ii < ret; ii++) {
fputc(buffer[ii], stdout);
}
fputs("\n", stdout);
}
CHECK(gnutls_bye(session, GNUTLS_SHUT_RDWR));
end:
tcp_close(sd);
gnutls_deinit(session);
gnutls_psk_free_client_credentials(pskcred);
gnutls_global_deinit();
return 0;
}
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