X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=src%2Fconnection.c;h=700a3548345398a436aaf9a26b5144714e85f230;hb=76ad95f5a7601b7e0549a4f4624443287f64a262;hp=880087b9fb6a92193ec280bf71e68151fc372ed8;hpb=b6debcde1dd7c16eb1102a9fe79d583c40c14b59;p=tlsproxy%2Ftlsproxy.git diff --git a/src/connection.c b/src/connection.c index 880087b..700a354 100644 --- a/src/connection.c +++ b/src/connection.c @@ -31,9 +31,10 @@ #include -/* Maximum line of a HTTP request line. Longer request lines are aborted with - * an error. The standard doesn't specify a maximum line length but this - * should be a good limit to make processing simpler. */ +/* 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 + * should be a good limit to make processing simpler. As HTTPS is used this + * doesn't limit long GET requests. */ #define MAX_REQUEST_LINE 4096 /* Format string used to send HTTP/1.0 error responses to the client. @@ -71,7 +72,8 @@ static int read_from_write_to(int from, int to); static void transfer_data_tls(int client, int server, gnutls_session_t client_session, gnutls_session_t server_session); -static int read_from_write_to_tls(gnutls_session_t from, gnutls_session_t to); +static int read_from_write_to_tls(gnutls_session_t from, gnutls_session_t to, + size_t buffer_size); static int connect_to_host(const char *hostname, const char *port); @@ -87,7 +89,7 @@ void handle_connection(int client_socket) { char host[MAX_REQUEST_LINE]; char port[5 + 1]; - int version_minor; + int version_minor; /* HTTP/1.x */ int result; /* client_x509_cred is used when talking to the client (acting as a TSL @@ -200,7 +202,7 @@ void handle_connection(int client_socket) { char path[1024]; FILE *file = NULL; - if (-2 == server_certificate_path(&file, host, path, sizeof(path))) { + if (-2 == server_certificate_file(&file, host, path, sizeof(path))) { /* We've established a connection, tell the client. */ fprintf(client_fd, "HTTP/1.0 200 Connection established\r\n"); fprintf(client_fd, "\r\n"); @@ -208,7 +210,7 @@ void handle_connection(int client_socket) { LOG(LOG_DEBUG, "transferring data"); - /* Proxy data between client and server until one suite is done + /* Proxy data between client and server until one side is done * (EOF or error). */ transfer_data(client_socket, server_socket); @@ -216,15 +218,15 @@ void handle_connection(int client_socket) { goto out; } - /* server_certificate_path() may open the file, close it. */ + /* server_certificate_file() may have opened the file, close it. */ if (NULL != file) { fclose(file); } } + /* Initialize TLS client credentials to talk to the server. */ result = initialize_tls_session_server(server_socket, &server_session, &server_x509_cred); - /* Initialize TLS client credentials to talk to the server. */ if (0 != result) { LOG(LOG_WARNING, "initialize_tls_session_server() failed"); send_forwarding_failure(client_fd); @@ -250,13 +252,14 @@ void handle_connection(int client_socket) { if (0 != verify_tls_connection(server_session, host)) { LOG(LOG_ERROR, "server certificate validation failed!"); /* We send the error message over our TLS connection to the client, - * but with an invalid certificate. */ + * but with an invalid certificate. No data is transfered from/to the + * target server. */ validation_failed = 1; } /* Initialize TLS server credentials to talk to the client. */ result = initialize_tls_session_client(client_socket, - /* use special host if the server + /* use a special host if the server * certificate was invalid */ (validation_failed) ? "invalid" : host, @@ -298,7 +301,7 @@ void handle_connection(int client_socket) { LOG(LOG_DEBUG, "transferring TLS data"); - /* Proxy data between client and server until one suite is done (EOF or + /* Proxy data between client and server until one side is done (EOF or * error). */ transfer_data_tls(client_socket, server_socket, client_session, server_session); @@ -354,23 +357,14 @@ static int initialize_tls_session_client(int peer_socket, /* The "invalid" hostname is special. If it's used we send an invalid * certificate to let the client know something is wrong. */ - use_invalid_cert = 0 == strcmp(hostname, "invalid"); + use_invalid_cert = (0 == strcmp(hostname, "invalid")); - /* Hostname too long. */ - if (sizeof(path) - strlen(PROXY_SERVER_CERT_FORMAT) <= strlen(hostname)) { - LOG(LOG_WARNING, - "initialize_tls_session_client(): hostname too long: '%s'", - hostname); - return -1; - } - /* Try to prevent path traversals in hostnames. */ - if (NULL != strstr(hostname, "..")) { - LOG(LOG_WARNING, - "initialize_tls_session_client(): possible path traversal: '%s'", - hostname); + if (0 != proxy_certificate_path(hostname, path, sizeof(path))) { + LOG(LOG_ERROR, + "initialize_tls_session_client(): \ +failed to get proxy certificate path"); return -1; } - snprintf(path, sizeof(path), PROXY_SERVER_CERT_FORMAT, hostname); result = gnutls_certificate_allocate_credentials(x509_cred); if (GNUTLS_E_SUCCESS != result) { @@ -386,18 +380,17 @@ gnutls_certificate_allocate_credentials(): %s", result = gnutls_certificate_set_x509_trust_file(*x509_cred, PROXY_CA_FILE, GNUTLS_X509_FMT_PEM); + if (0 >= result) { + LOG(LOG_ERROR, + "initialize_tls_session_client(): can't read CA file: '%s'", + PROXY_CA_FILE); + gnutls_certificate_free_credentials(*x509_cred); + return -1; + } + } /* If the invalid hostname was specified do nothing, we use a self-signed * certificate in this case. */ - } else { - result = 1; - } - if (0 >= result) { - LOG(LOG_ERROR, - "initialize_tls_session_client(): can't read CA file: '%s'", - PROXY_CA_FILE); - gnutls_certificate_free_credentials(*x509_cred); - return -1; - } + /* And certificate for this website and proxy's private key. */ if (!use_invalid_cert) { result = gnutls_certificate_set_x509_key_file(*x509_cred, @@ -519,7 +512,7 @@ static int read_http_request(FILE *client_fd, char *request, size_t length) { return -2; } - while (NULL != fgets(buffer, MAX_REQUEST_LINE, client_fd)) { + while (NULL != fgets(buffer, sizeof(buffer), client_fd)) { /* End of header. */ if (0 == strcmp(buffer, "\n") || 0 == strcmp(buffer, "\r\n")) { break; @@ -555,15 +548,26 @@ static void tls_send_invalid_cert_message(gnutls_session_t session) { #define RESPONSE_ERROR "500 Internal Server Error" #define RESPONSE_MSG "Server certificate validation failed, check logs." + int result; char buffer[sizeof(HTTP_RESPONSE_FORMAT) - 1 /* '\0' */ - 4 * 2 /* four %s */ + (sizeof(RESPONSE_ERROR) - 1 /* '\0' */) * 3 + sizeof(RESPONSE_MSG) - 1 /* '\0' */ + 1 /* '\0' */]; - snprintf(buffer, sizeof(buffer), - HTTP_RESPONSE_FORMAT, - RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_MSG); + result = snprintf(buffer, sizeof(buffer), + HTTP_RESPONSE_FORMAT, + RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR, + RESPONSE_MSG); + if (result < 0) { + LOG_PERROR(LOG_ERROR, + "tls_send_invalid_cert_message(): snprintf failed"); + return; + } else if ((size_t)result >= sizeof(buffer)) { + LOG(LOG_ERROR, + "tls_send_invalid_cert_message(): snprintf buffer too short"); + return; + } gnutls_record_send(session, buffer, sizeof(buffer) - 1); /* don't send trailing '\0' */ @@ -654,6 +658,8 @@ static int read_from_write_to(int from, int to) { static void transfer_data_tls(int client, int server, gnutls_session_t client_session, gnutls_session_t server_session) { + size_t buffer_size; + struct pollfd fds[2]; fds[0].fd = client; fds[0].events = POLLIN | POLLPRI | POLLHUP | POLLERR; @@ -662,6 +668,14 @@ static void transfer_data_tls(int client, int server, fds[1].events = POLLIN | POLLPRI | POLLHUP | POLLERR; fds[1].revents = 0; + /* Get maximum possible buffer size. */ + buffer_size = gnutls_record_get_max_size(client_session); + if (buffer_size > gnutls_record_get_max_size(server_session)) { + buffer_size = gnutls_record_get_max_size(server_session); + } + LOG(LOG_DEBUG, "transfer_data_tls(): suggested buffer size: %ld", + (long int)buffer_size); + for (;;) { int result = poll(fds, 2, -1 /* no timeout */); if (result < 0) { @@ -671,14 +685,16 @@ static void transfer_data_tls(int client, int server, /* Data available from client. */ if (fds[0].revents & POLLIN || fds[0].revents & POLLPRI) { - if (0 != read_from_write_to_tls(client_session, server_session)) { + if (0 != read_from_write_to_tls(client_session, server_session, + buffer_size)) { /* EOF (or other error) */ break; } } /* Data available from server. */ if (fds[1].revents & POLLIN || fds[1].revents & POLLPRI) { - if (0 != read_from_write_to_tls(server_session, client_session)) { + if (0 != read_from_write_to_tls(server_session, client_session, + buffer_size)) { /* EOF (or other error) */ break; } @@ -697,26 +713,19 @@ static void transfer_data_tls(int client, int server, /* Read available data from session from and write to session to. */ static int read_from_write_to_tls(gnutls_session_t from, - gnutls_session_t to) { - size_t size; + gnutls_session_t to, + size_t buffer_size) { ssize_t size_read; ssize_t size_written; char buffer[16384]; - /* Get maximum possible buffer size. */ - size = gnutls_record_get_max_size(from); - LOG(LOG_DEBUG, "read_from_write_to_tls(): suggested buffer size: %ld", - (long int)size); - if (size > gnutls_record_get_max_size(to)) { - size = gnutls_record_get_max_size(to); - } - if (size > sizeof(buffer)) { - size = sizeof(buffer); + if (buffer_size > sizeof(buffer)) { + buffer_size = sizeof(buffer); } LOG(LOG_DEBUG, "read_from_write_to_tls(): used buffer size: %ld", - (long int)size); + (long int)buffer_size); - size_read = gnutls_record_recv(from, buffer, size); + size_read = gnutls_record_recv(from, buffer, buffer_size); if (0 > size_read) { LOG(LOG_WARNING, "read_from_write_to_tls(): gnutls_record_recv(): %s", gnutls_strerror((int)size_read));