Working bot answering PING, and its C wrapper.

1 files changed, 165 insertions, 0 deletions

diff --git a/src/tls.c b/src/tls.c
new file mode 100644
index 0000000..6b81bd3
--- /dev/null
+++ b/src/tls.c
@@ -0,0 +1,165 @@
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tcp.h"
+#include "tls.h"
+
+int sd = 0;
+gnutls_session_t session;
+gnutls_certificate_credentials_t xcred;
+
+void tls_init(void)
+{
+    gnutls_global_init();
+    gnutls_certificate_allocate_credentials(&xcred);
+    //gnutls_certificate_set_x509_trust_file(xcred, cafile, GNUTLS_X509_FMT_PEM);
+    //gnutls_certificate_set_verify_function(xcred, _verify_certificate_callback);
+    //gnutls_certificate_set_x509_key_file (xcred, "cert.pem", "key.pem", GNUTLS_X509_FMT_PEM);
+    gnutls_init(&session, GNUTLS_CLIENT);
+
+    // Only usefull if accessing a virtual hosting server
+    //gnutls_session_set_ptr(session, (void *) "my_host_name");
+    //gnutls_server_name_set(session, GNUTLS_NAME_DNS, "my_host_name", strlen("my_host_name"));
+
+    gnutls_set_default_priority(session);
+    gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
+}
+
+int tls_connect(const char* const host, const unsigned short port)
+{
+    int ret;
+    sd = tcp_connect(host, port);
+    if (sd < 0) {
+        tls_clean();
+        exit(101);
+    }
+
+    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, "TLS Handshake failed\n");
+        gnutls_perror(ret);
+        tls_clean();
+        exit(102);
+    } else {
+        char *desc;
+
+        desc = gnutls_session_get_desc(session);
+        printf("# TLS Session info: %s\n", desc);
+        gnutls_free(desc);
+    }
+
+    int sf = fcntl (sd, F_GETFL, 0);
+    if (sf == -1) {
+        perror("fcntl get");
+        return -1;
+    }
+    fcntl(sd, F_SETFL, sf | O_NONBLOCK);
+    if (sf == -1) {
+        perror("fcntl set");
+        return -1;
+    }
+
+    return sd;
+}
+
+int tls_read(int (*input_handler_callback)(const char* const sbuf, const int len))
+{
+    char sbuf[512]; /* string buffer */
+    int len = 0;  /* len read from the server */
+    len = gnutls_record_recv(session, sbuf, sizeof(sbuf));
+    if (len == 0) {
+        printf("Server has closed the TLS connection\n");
+        tls_clean();
+        return 1;
+    } else if (len < 0 && gnutls_error_is_fatal(len) == 0) {
+        fprintf(stderr, "*** Warning: %s\n", gnutls_strerror(len));
+        return 3;
+    } else if (len < 0) {
+        fprintf(stderr, "*** Error: %s\n", gnutls_strerror(len));
+        tls_clean();
+        return 2;
+    } else {
+        if (input_handler_callback(sbuf, len) != 0) {
+            return 0;
+        }
+    }
+    return 4;
+}
+
+void tls_send(char *buf, int len)
+{
+    gnutls_record_send(session, buf, len);
+}
+
+void tls_close(void) {
+    gnutls_bye(session, GNUTLS_SHUT_RDWR);
+    tls_clean();
+}
+
+void tls_clean(void)
+{
+    tcp_close(sd);
+    gnutls_deinit(session);
+    gnutls_certificate_free_credentials(xcred);
+    gnutls_global_deinit();
+}
+
+/* This function will verify the peer's certificate, and check
+ * if the hostname matches, as well as the activation, expiration dates. */
+//static int _verify_certificate_callback(gnutls_session_t session)
+//{
+//    unsigned int status;
+//    int ret, type;
+//    const char *hostname;
+//    gnutls_datum_t out;
+//
+//    /* read hostname */
+//    hostname = gnutls_session_get_ptr(session);
+//
+//    /* This verification function uses the trusted CAs in the credentials
+//     * structure. So you must have installed one or more CA certificates. */
+//    gnutls_typed_vdata_st data[2];
+//
+//    memset(data, 0, sizeof(data));
+//
+//    data[0].type = GNUTLS_DT_DNS_HOSTNAME;
+//    data[0].data = (void*)hostname;
+//
+//    data[1].type = GNUTLS_DT_KEY_PURPOSE_OID;
+//    data[1].data = (void*)GNUTLS_KP_TLS_WWW_SERVER;
+//
+//    ret = gnutls_certificate_verify_peers(session, data, 2, &status);
+//    if (ret < 0) {
+//        printf("Error\n");
+//        return GNUTLS_E_CERTIFICATE_ERROR;
+//    }
+//
+//    type = gnutls_certificate_type_get(session);
+//
+//    ret = gnutls_certificate_verification_status_print(status, type, &out, 0);
+//    if (ret < 0) {
+//        printf("Error\n");
+//        return GNUTLS_E_CERTIFICATE_ERROR;
+//    }
+//
+//    printf("%s", out.data);
+//
+//    gnutls_free(out.data);
+//
+//    if (status != 0)        /* Certificate is not trusted */
+//        return GNUTLS_E_CERTIFICATE_ERROR;
+//
+//    /* notify gnutls to continue handshake normally */
+//    return 0;
+//}