diff options
Diffstat (limited to 'doc/examples/ex-serv-psk.c')
| -rw-r--r-- | doc/examples/ex-serv-psk.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/doc/examples/ex-serv-psk.c b/doc/examples/ex-serv-psk.c new file mode 100644 index 0000000..b6d5d11 --- /dev/null +++ b/doc/examples/ex-serv-psk.c @@ -0,0 +1,203 @@ +/* This example code is placed in the public domain. */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <arpa/inet.h> +#include <netinet/in.h> +#include <string.h> +#include <unistd.h> +#include <gnutls/gnutls.h> + +#define KEYFILE "key.pem" +#define CERTFILE "cert.pem" +#define CAFILE "/etc/ssl/certs/ca-certificates.crt" +#define CRLFILE "crl.pem" + +#define LOOP_CHECK(rval, cmd) \ + do { \ + rval = cmd; \ + } while(rval == GNUTLS_E_AGAIN || rval == GNUTLS_E_INTERRUPTED) + +/* This is a sample TLS echo server, supporting X.509 and PSK + authentication. + */ + +#define SOCKET_ERR(err,s) if(err==-1) {perror(s);return(1);} +#define MAX_BUF 1024 +#define PORT 5556 /* listen to 5556 port */ + +static int +pskfunc(gnutls_session_t session, const char *username, + gnutls_datum_t * key) +{ + printf("psk: username %s\n", username); + key->data = gnutls_malloc(4); + key->data[0] = 0xDE; + key->data[1] = 0xAD; + key->data[2] = 0xBE; + key->data[3] = 0xEF; + key->size = 4; + return 0; +} + +int main(void) +{ + int err, listen_sd; + int sd, ret; + struct sockaddr_in sa_serv; + struct sockaddr_in sa_cli; + socklen_t client_len; + char topbuf[512]; + gnutls_session_t session; + gnutls_certificate_credentials_t x509_cred; + gnutls_psk_server_credentials_t psk_cred; + gnutls_priority_t priority_cache; + char buffer[MAX_BUF + 1]; + int optval = 1; + int kx; + + if (gnutls_check_version("3.1.4") == NULL) { + fprintf(stderr, "GnuTLS 3.1.4 or later is required for this example\n"); + exit(1); + } + + /* for backwards compatibility with gnutls < 3.3.0 */ + gnutls_global_init(); + + gnutls_certificate_allocate_credentials(&x509_cred); + gnutls_certificate_set_x509_trust_file(x509_cred, CAFILE, + GNUTLS_X509_FMT_PEM); + + gnutls_certificate_set_x509_crl_file(x509_cred, CRLFILE, + GNUTLS_X509_FMT_PEM); + + gnutls_certificate_set_x509_key_file(x509_cred, CERTFILE, KEYFILE, + GNUTLS_X509_FMT_PEM); + + gnutls_psk_allocate_server_credentials(&psk_cred); + gnutls_psk_set_server_credentials_function(psk_cred, pskfunc); + + /* pre-3.6.3 equivalent: + * gnutls_priority_init(&priority_cache, + * "NORMAL:+PSK:+ECDHE-PSK:+DHE-PSK", + * NULL); + */ + gnutls_priority_init2(&priority_cache, + "+ECDHE-PSK:+DHE-PSK:+PSK", + NULL, GNUTLS_PRIORITY_INIT_DEF_APPEND); + + gnutls_certificate_set_known_dh_params(x509_cred, GNUTLS_SEC_PARAM_MEDIUM); + + /* Socket operations + */ + listen_sd = socket(AF_INET, SOCK_STREAM, 0); + SOCKET_ERR(listen_sd, "socket"); + + memset(&sa_serv, '\0', sizeof(sa_serv)); + sa_serv.sin_family = AF_INET; + sa_serv.sin_addr.s_addr = INADDR_ANY; + sa_serv.sin_port = htons(PORT); /* Server Port number */ + + setsockopt(listen_sd, SOL_SOCKET, SO_REUSEADDR, (void *) &optval, + sizeof(int)); + + err = + bind(listen_sd, (struct sockaddr *) &sa_serv, sizeof(sa_serv)); + SOCKET_ERR(err, "bind"); + err = listen(listen_sd, 1024); + SOCKET_ERR(err, "listen"); + + printf("Server ready. Listening to port '%d'.\n\n", PORT); + + client_len = sizeof(sa_cli); + for (;;) { + gnutls_init(&session, GNUTLS_SERVER); + gnutls_priority_set(session, priority_cache); + gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, + x509_cred); + gnutls_credentials_set(session, GNUTLS_CRD_PSK, psk_cred); + + /* request client certificate if any. + */ + gnutls_certificate_server_set_request(session, + GNUTLS_CERT_REQUEST); + + sd = accept(listen_sd, (struct sockaddr *) &sa_cli, + &client_len); + + printf("- connection from %s, port %d\n", + inet_ntop(AF_INET, &sa_cli.sin_addr, topbuf, + sizeof(topbuf)), ntohs(sa_cli.sin_port)); + + gnutls_transport_set_int(session, sd); + LOOP_CHECK(ret, gnutls_handshake(session)); + if (ret < 0) { + close(sd); + gnutls_deinit(session); + fprintf(stderr, + "*** Handshake has failed (%s)\n\n", + gnutls_strerror(ret)); + continue; + } + printf("- Handshake was completed\n"); + + kx = gnutls_kx_get(session); + if (kx == GNUTLS_KX_PSK || kx == GNUTLS_KX_DHE_PSK || + kx == GNUTLS_KX_ECDHE_PSK) { + printf("- User %s was connected\n", + gnutls_psk_server_get_username(session)); + } + + /* see the Getting peer's information example */ + /* print_info(session); */ + + for (;;) { + LOOP_CHECK(ret, gnutls_record_recv(session, buffer, MAX_BUF)); + + if (ret == 0) { + printf + ("\n- Peer has closed the GnuTLS connection\n"); + break; + } else if (ret < 0 + && gnutls_error_is_fatal(ret) == 0) { + fprintf(stderr, "*** Warning: %s\n", + gnutls_strerror(ret)); + } else if (ret < 0) { + fprintf(stderr, "\n*** Received corrupted " + "data(%d). Closing the connection.\n\n", + ret); + break; + } else if (ret > 0) { + /* echo data back to the client + */ + gnutls_record_send(session, buffer, ret); + } + } + printf("\n"); + /* do not wait for the peer to close the connection. + */ + LOOP_CHECK(ret, gnutls_bye(session, GNUTLS_SHUT_WR)); + + close(sd); + gnutls_deinit(session); + + } + close(listen_sd); + + gnutls_certificate_free_credentials(x509_cred); + gnutls_psk_free_server_credentials(psk_cred); + + gnutls_priority_deinit(priority_cache); + + gnutls_global_deinit(); + + return 0; + +} |