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Diffstat (limited to 'doc/examples/ex-serv-x509.c')
| -rw-r--r-- | doc/examples/ex-serv-x509.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/doc/examples/ex-serv-x509.c b/doc/examples/ex-serv-x509.c new file mode 100644 index 0000000..df57207 --- /dev/null +++ b/doc/examples/ex-serv-x509.c @@ -0,0 +1,198 @@ +/* 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> +#include <assert.h> + +#define KEYFILE "key.pem" +#define CERTFILE "cert.pem" +#define CAFILE "/etc/ssl/certs/ca-certificates.crt" +#define CRLFILE "crl.pem" + +#define CHECK(x) assert((x)>=0) +#define LOOP_CHECK(rval, cmd) \ + do { \ + rval = cmd; \ + } while(rval == GNUTLS_E_AGAIN || rval == GNUTLS_E_INTERRUPTED) + +/* The OCSP status file contains up to date information about revocation + * of the server's certificate. That can be periodically be updated + * using: + * $ ocsptool --ask --load-cert your_cert.pem --load-issuer your_issuer.pem + * --load-signer your_issuer.pem --outfile ocsp-status.der + */ +#define OCSP_STATUS_FILE "ocsp-status.der" + +/* This is a sample TLS 1.0 echo server, using X.509 authentication and + * OCSP stapling support. + */ + +#define MAX_BUF 1024 +#define PORT 5556 /* listen to 5556 port */ + +int main(void) +{ + int listen_sd; + int sd, ret; + gnutls_certificate_credentials_t x509_cred; + gnutls_priority_t priority_cache; + struct sockaddr_in sa_serv; + struct sockaddr_in sa_cli; + socklen_t client_len; + char topbuf[512]; + gnutls_session_t session; + char buffer[MAX_BUF + 1]; + int optval = 1; + + /* for backwards compatibility with gnutls < 3.3.0 */ + CHECK(gnutls_global_init()); + + CHECK(gnutls_certificate_allocate_credentials(&x509_cred)); + + CHECK(gnutls_certificate_set_x509_trust_file(x509_cred, CAFILE, + GNUTLS_X509_FMT_PEM)); + + CHECK(gnutls_certificate_set_x509_crl_file(x509_cred, CRLFILE, + GNUTLS_X509_FMT_PEM)); + + /* The following code sets the certificate key pair as well as, + * an OCSP response which corresponds to it. It is possible + * to set multiple key-pairs and multiple OCSP status responses + * (the latter since 3.5.6). See the manual pages of the individual + * functions for more information. + */ + CHECK(gnutls_certificate_set_x509_key_file(x509_cred, CERTFILE, + KEYFILE, + GNUTLS_X509_FMT_PEM)); + + CHECK(gnutls_certificate_set_ocsp_status_request_file(x509_cred, + OCSP_STATUS_FILE, + 0)); + + CHECK(gnutls_priority_init(&priority_cache, NULL, NULL)); + + /* Instead of the default options as shown above one could specify + * additional options such as server precedence in ciphersuite selection + * as follows: + * gnutls_priority_init2(&priority_cache, + * "%SERVER_PRECEDENCE", + * NULL, GNUTLS_PRIORITY_INIT_DEF_APPEND); + */ + +#if GNUTLS_VERSION_NUMBER >= 0x030506 + /* only available since GnuTLS 3.5.6, on previous versions see + * gnutls_certificate_set_dh_params(). */ + gnutls_certificate_set_known_dh_params(x509_cred, GNUTLS_SEC_PARAM_MEDIUM); +#endif + + /* Socket operations + */ + listen_sd = socket(AF_INET, SOCK_STREAM, 0); + + 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)); + + bind(listen_sd, (struct sockaddr *) &sa_serv, sizeof(sa_serv)); + + listen(listen_sd, 1024); + + printf("Server ready. Listening to port '%d'.\n\n", PORT); + + client_len = sizeof(sa_cli); + for (;;) { + CHECK(gnutls_init(&session, GNUTLS_SERVER)); + CHECK(gnutls_priority_set(session, priority_cache)); + CHECK(gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, + x509_cred)); + + /* We don't request any certificate from the client. + * If we did we would need to verify it. One way of + * doing that is shown in the "Verifying a certificate" + * example. + */ + gnutls_certificate_server_set_request(session, + GNUTLS_CERT_IGNORE); + gnutls_handshake_set_timeout(session, + GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT); + + 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"); + + /* 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 + */ + CHECK(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_priority_deinit(priority_cache); + + gnutls_global_deinit(); + + return 0; + +} |