#include <poll.h>
#include <unistd.h>
+#include <gnutls/x509.h>
+
/* Maximum length of a HTTP request line. Longer request lines are aborted
* with an error. The standard doesn't specify a maximum line length but this
/* Format string used to send HTTP/1.0 error responses to the client.
*
* %s is used 5 times, first is the error code, then additional headers, next
- * two are the error code (no %n$s!), the last is the message. */
+ * two are the error code (no %n$s which is not in C98!), the last is the
+ * message. */
#define HTTP_RESPONSE_FORMAT "HTTP/1.0 %s\r\n\
Content-Type: text/html; charset=US-ASCII\r\n\
%s\r\n\
static int parse_request(const char *buffer, char *host, char *port,
int *version_minor);
+static void log_session_information(gnutls_session_t session);
+
void handle_connection(int client_socket) {
int server_socket;
/* Check response of proxy server. */
if (strncmp(buffer, "HTTP/1.0 200", 12)) {
- LOG(WARNING, "bad proxy response: %s", buffer);
+ LOG(WARNING, "bad proxy response: >%s<", buffer);
send_forwarding_failure(client_fd_write);
goto out;
}
LOG(DEBUG1, "server TLS handshake finished");
+ if (global_log_level >= LOG_DEBUG2_LEVEL) {
+ log_session_information(server_session);
+ }
+
/* Make sure the server certificate is valid and known. */
if (verify_tls_connection(server_session, host) != 0) {
LOG(ERROR, "server certificate validation failed!");
LOG(DEBUG1, "client TLS handshake finished");
+ if (global_log_level >= LOG_DEBUG2_LEVEL) {
+ log_session_information(client_session);
+ }
+
/* Tell the client that the verification failed. Shouldn't be necessary as
* the client should terminate the connection because he received the
* invalid certificate but better be sure. */
}
if (client_session_init) {
gnutls_deinit(client_session);
- gnutls_certificate_free_cas(client_x509_cred);
- gnutls_certificate_free_keys(client_x509_cred);
gnutls_certificate_free_credentials(client_x509_cred);
}
const char msg[] = "Server certificate validation failed, check logs.";
int result;
+ ssize_t size_written;
char buffer[sizeof(HTTP_RESPONSE_FORMAT)
+ 3 * sizeof(error) + sizeof(msg)];
error, "", error, error, msg);
assert(result > 0 && (size_t)result < sizeof(buffer));
- gnutls_record_send(session, buffer, strlen(buffer));
+ size_written = gnutls_record_send(session, buffer, strlen(buffer));
+ if (size_written < 0) {
+ LOG(WARNING, "tls_send_invalid_cert_message(): "
+ "gnutls_record_send(): %s",
+ gnutls_strerror((int)size_written));
+ }
+ /* Just an error message, no need to check if everything was written. */
}
return -1;
}
if (size_read != size_written) {
- LOG(ERROR, "read_from_write_to(): only written %ld of %ld bytes!",
- (long int)size_written, (long int)size_read);
+ LOG(ERROR, "read_from_write_to(): only written %zu of %zu bytes!",
+ size_written, size_read);
return -1;
}
if (gnutls_record_get_max_size(server_session) < buffer_size) {
buffer_size = gnutls_record_get_max_size(server_session);
}
- LOG(DEBUG2, "transfer_data_tls(): suggested buffer size: %ld",
- (long int)buffer_size);
+ LOG(DEBUG2, "transfer_data_tls(): suggested buffer size: %zu",
+ buffer_size);
for (;;) {
int result = poll(fds, 2 /* fd count */, -1 /* no timeout */);
size_t buffer_size) {
ssize_t size_read;
ssize_t size_written;
- char buffer[16384];
+ char buffer[16384]; /* GnuTLS default maximum */
if (buffer_size > sizeof(buffer)) {
- LOG(WARNING, "read_from_write_to_tls(): reduced buffer size to %ld",
- (long int)(sizeof(buffer)));
+ LOG(WARNING, "read_from_write_to_tls(): reduced buffer size to %zu",
+ sizeof(buffer));
buffer_size = sizeof(buffer);
}
size_read = gnutls_record_recv(from, buffer, buffer_size);
if (size_read < 0) {
+ /* Allow rehandshakes. As handshakes might be insecure make sure that
+ * %SAFE_RENEGOTIATION is used in GnuTLS's priority string. */
+ if (size_read == GNUTLS_E_REHANDSHAKE) {
+ int result = gnutls_handshake(from);
+ if (result != GNUTLS_E_SUCCESS) {
+ LOG(WARNING, "server TLS rehandshake failed: %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+ return 0;
+ }
+
LOG(WARNING, "read_from_write_to_tls(): gnutls_record_recv(): %s",
gnutls_strerror((int)size_read));
return -1;
return -1;
}
if (size_read != size_written) {
- LOG(ERROR, "read_from_write_to_tls(): only written %ld of %ld bytes!",
- (long int)size_written, (long int)size_read);
+ LOG(ERROR, "read_from_write_to_tls(): only written %zu of %zu bytes!",
+ size_written, size_read);
return -1;
}
return 0;
}
+
+
+static void log_session_information(gnutls_session_t session) {
+ /* From doc/examples/ex-session-info.c of GnuTLS 3.2.3's tarball and
+ * modified, thanks. */
+
+ const char *tmp;
+ gnutls_credentials_type_t cred;
+ gnutls_kx_algorithm_t kx;
+ int dhe, ecdh;
+
+ dhe = 0;
+ ecdh = 0;
+
+ /* Key exchange algorithm. */
+ kx = gnutls_kx_get(session);
+ LOG(DEBUG2, "- key exchange: %s", gnutls_kx_get_name(kx));
+
+ /* Authentication type. */
+ cred = gnutls_auth_get_type(session);
+ switch (cred) {
+ case GNUTLS_CRD_CERTIFICATE:
+ if (kx == GNUTLS_KX_DHE_RSA
+ || kx == GNUTLS_KX_DHE_DSS) {
+ dhe = 1;
+#ifdef GNUTLS_KX_ECDHE_RSA
+ } else if (kx == GNUTLS_KX_ECDHE_RSA
+ || kx == GNUTLS_KX_ECDHE_ECDSA) {
+ ecdh = 1;
+#endif
+ }
+ break;
+
+ case GNUTLS_CRD_IA:
+ case GNUTLS_CRD_SRP:
+ case GNUTLS_CRD_PSK:
+ case GNUTLS_CRD_ANON:
+ default:
+ /* This shouldn't occur. */
+ LOG(WARNING, "unexpected authentication method: %d", cred);
+ break;
+ }
+
+ /* Information about key exchange. */
+ if (dhe) {
+ LOG(DEBUG2, "- ephemeral DH using prime of %d bits",
+ gnutls_dh_get_prime_bits(session));
+ } else if (ecdh) {
+#ifdef GNUTLS_KX_ECDHE_RSA
+ LOG(DEBUG2, "- ephemeral ECDH using curve %s",
+ gnutls_ecc_curve_get_name(gnutls_ecc_curve_get(session)));
+#endif
+ }
+
+ tmp = gnutls_protocol_get_name(gnutls_protocol_get_version(session));
+ LOG(DEBUG2, "- protocol: %s", tmp); /* e.g. TLS 1.0 */
+
+ tmp = gnutls_certificate_type_get_name(gnutls_certificate_type_get(session));
+ LOG(DEBUG2, "- certificate type: %s", tmp);
+
+ tmp = gnutls_compression_get_name(gnutls_compression_get(session));
+ LOG(DEBUG2, "- compression: %s", tmp);
+
+ tmp = gnutls_cipher_get_name(gnutls_cipher_get(session));
+ LOG(DEBUG2, "- cipher: %s", tmp);
+
+ tmp = gnutls_mac_get_name(gnutls_mac_get(session));
+ LOG(DEBUG2, "- MAC: %s", tmp);
+}