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Diffstat (limited to '')
-rw-r--r-- | doc/examples/ex-client-anon.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/doc/examples/ex-client-anon.c b/doc/examples/ex-client-anon.c new file mode 100644 index 0000000..39d5a7e --- /dev/null +++ b/doc/examples/ex-client-anon.c @@ -0,0 +1,118 @@ +/* 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 anonymous authentication. + */ + +#define LOOP_CHECK(rval, cmd) \ + do { \ + rval = cmd; \ + } while(rval == GNUTLS_E_AGAIN || rval == GNUTLS_E_INTERRUPTED); \ + assert(rval >= 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]; + gnutls_anon_client_credentials_t anoncred; + /* Need to enable anonymous KX specifically. */ + + gnutls_global_init(); + + gnutls_anon_allocate_client_credentials(&anoncred); + + /* Initialize TLS session + */ + gnutls_init(&session, GNUTLS_CLIENT); + + /* Use default priorities */ + gnutls_priority_set_direct(session, + "PERFORMANCE:+ANON-ECDH:+ANON-DH", + NULL); + + /* put the anonymous credentials to the current session + */ + gnutls_credentials_set(session, GNUTLS_CRD_ANON, anoncred); + + /* 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); + } + + LOOP_CHECK(ret, gnutls_record_send(session, MSG, strlen(MSG))); + + LOOP_CHECK(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); + } + + LOOP_CHECK(ret, gnutls_bye(session, GNUTLS_SHUT_RDWR)); + + end: + + tcp_close(sd); + + gnutls_deinit(session); + + gnutls_anon_free_client_credentials(anoncred); + + gnutls_global_deinit(); + + return 0; +} |