/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2012 Lennart Poettering Copyright 2012 Zbigniew Jędrzejewski-Szmek systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <stddef.h> #include <stdio.h> #include <string.h> #include "microhttpd-util.h" #include "log.h" #include "macro.h" #include "util.h" #include "strv.h" #ifdef HAVE_GNUTLS #include <gnutls/gnutls.h> #include <gnutls/x509.h> #endif void microhttpd_logger(void *arg, const char *fmt, va_list ap) { char *f; f = strjoina("microhttpd: ", fmt); DISABLE_WARNING_FORMAT_NONLITERAL; log_internalv(LOG_INFO, 0, NULL, 0, NULL, f, ap); REENABLE_WARNING; } static int mhd_respond_internal(struct MHD_Connection *connection, enum MHD_RequestTerminationCode code, char *buffer, size_t size, enum MHD_ResponseMemoryMode mode) { struct MHD_Response *response; int r; assert(connection); response = MHD_create_response_from_buffer(size, buffer, mode); if (!response) return MHD_NO; log_debug("Queing response %u: %s", code, buffer); MHD_add_response_header(response, "Content-Type", "text/plain"); r = MHD_queue_response(connection, code, response); MHD_destroy_response(response); return r; } int mhd_respond(struct MHD_Connection *connection, enum MHD_RequestTerminationCode code, const char *message) { return mhd_respond_internal(connection, code, (char*) message, strlen(message), MHD_RESPMEM_PERSISTENT); } int mhd_respond_oom(struct MHD_Connection *connection) { return mhd_respond(connection, MHD_HTTP_SERVICE_UNAVAILABLE, "Out of memory.\n"); } int mhd_respondf(struct MHD_Connection *connection, enum MHD_RequestTerminationCode code, const char *format, ...) { char *m; int r; va_list ap; assert(connection); assert(format); va_start(ap, format); r = vasprintf(&m, format, ap); va_end(ap); if (r < 0) return respond_oom(connection); return mhd_respond_internal(connection, code, m, r, MHD_RESPMEM_MUST_FREE); } #ifdef HAVE_GNUTLS static struct { const char *const names[4]; int level; bool enabled; } gnutls_log_map[] = { { {"0"}, LOG_DEBUG }, { {"1", "audit"}, LOG_WARNING, true}, /* gnutls session audit */ { {"2", "assert"}, LOG_DEBUG }, /* gnutls assert log */ { {"3", "hsk", "ext"}, LOG_DEBUG }, /* gnutls handshake log */ { {"4", "rec"}, LOG_DEBUG }, /* gnutls record log */ { {"5", "dtls"}, LOG_DEBUG }, /* gnutls DTLS log */ { {"6", "buf"}, LOG_DEBUG }, { {"7", "write", "read"}, LOG_DEBUG }, { {"8"}, LOG_DEBUG }, { {"9", "enc", "int"}, LOG_DEBUG }, }; static void log_func_gnutls(int level, const char *message) { assert_se(message); if (0 <= level && level < (int) ELEMENTSOF(gnutls_log_map)) { if (gnutls_log_map[level].enabled) log_internal(gnutls_log_map[level].level, 0, NULL, 0, NULL, "gnutls %d/%s: %s", level, gnutls_log_map[level].names[1], message); } else { log_debug("Received GNUTLS message with unknown level %d.", level); log_internal(LOG_DEBUG, 0, NULL, 0, NULL, "gnutls: %s", message); } } static void log_reset_gnutls_level(void) { int i; for (i = ELEMENTSOF(gnutls_log_map) - 1; i >= 0; i--) if (gnutls_log_map[i].enabled) { log_debug("Setting gnutls log level to %d", i); gnutls_global_set_log_level(i); break; } } static int log_enable_gnutls_category(const char *cat) { unsigned i; if (streq(cat, "all")) { for (i = 0; i < ELEMENTSOF(gnutls_log_map); i++) gnutls_log_map[i].enabled = true; log_reset_gnutls_level(); return 0; } else for (i = 0; i < ELEMENTSOF(gnutls_log_map); i++) if (strv_contains((char**)gnutls_log_map[i].names, cat)) { gnutls_log_map[i].enabled = true; log_reset_gnutls_level(); return 0; } log_error("No such log category: %s", cat); return -EINVAL; } int setup_gnutls_logger(char **categories) { char **cat; int r; gnutls_global_set_log_function(log_func_gnutls); if (categories) { STRV_FOREACH(cat, categories) { r = log_enable_gnutls_category(*cat); if (r < 0) return r; } } else log_reset_gnutls_level(); return 0; } static int verify_cert_authorized(gnutls_session_t session) { unsigned status; gnutls_certificate_type_t type; gnutls_datum_t out; int r; r = gnutls_certificate_verify_peers2(session, &status); if (r < 0) return log_error_errno(r, "gnutls_certificate_verify_peers2 failed: %m"); type = gnutls_certificate_type_get(session); r = gnutls_certificate_verification_status_print(status, type, &out, 0); if (r < 0) return log_error_errno(r, "gnutls_certificate_verification_status_print failed: %m"); log_debug("Certificate status: %s", out.data); gnutls_free(out.data); return status == 0 ? 0 : -EPERM; } static int get_client_cert(gnutls_session_t session, gnutls_x509_crt_t *client_cert) { const gnutls_datum_t *pcert; unsigned listsize; gnutls_x509_crt_t cert; int r; assert(session); assert(client_cert); pcert = gnutls_certificate_get_peers(session, &listsize); if (!pcert || !listsize) { log_error("Failed to retrieve certificate chain"); return -EINVAL; } r = gnutls_x509_crt_init(&cert); if (r < 0) { log_error("Failed to initialize client certificate"); return r; } /* Note that by passing values between 0 and listsize here, you can get access to the CA's certs */ r = gnutls_x509_crt_import(cert, &pcert[0], GNUTLS_X509_FMT_DER); if (r < 0) { log_error("Failed to import client certificate"); gnutls_x509_crt_deinit(cert); return r; } *client_cert = cert; return 0; } static int get_auth_dn(gnutls_x509_crt_t client_cert, char **buf) { size_t len = 0; int r; assert(buf); assert(*buf == NULL); r = gnutls_x509_crt_get_dn(client_cert, NULL, &len); if (r != GNUTLS_E_SHORT_MEMORY_BUFFER) { log_error("gnutls_x509_crt_get_dn failed"); return r; } *buf = malloc(len); if (!*buf) return log_oom(); gnutls_x509_crt_get_dn(client_cert, *buf, &len); return 0; } static inline void gnutls_x509_crt_deinitp(gnutls_x509_crt_t *p) { gnutls_x509_crt_deinit(*p); } int check_permissions(struct MHD_Connection *connection, int *code, char **hostname) { const union MHD_ConnectionInfo *ci; gnutls_session_t session; _cleanup_(gnutls_x509_crt_deinitp) gnutls_x509_crt_t client_cert = NULL; _cleanup_free_ char *buf = NULL; int r; assert(connection); assert(code); *code = 0; ci = MHD_get_connection_info(connection, MHD_CONNECTION_INFO_GNUTLS_SESSION); if (!ci) { log_error("MHD_get_connection_info failed: session is unencrypted"); *code = mhd_respond(connection, MHD_HTTP_FORBIDDEN, "Encrypted connection is required"); return -EPERM; } session = ci->tls_session; assert(session); r = get_client_cert(session, &client_cert); if (r < 0) { *code = mhd_respond(connection, MHD_HTTP_UNAUTHORIZED, "Authorization through certificate is required"); return -EPERM; } r = get_auth_dn(client_cert, &buf); if (r < 0) { *code = mhd_respond(connection, MHD_HTTP_UNAUTHORIZED, "Failed to determine distinguished name from certificate"); return -EPERM; } log_debug("Connection from %s", buf); if (hostname) { *hostname = buf; buf = NULL; } r = verify_cert_authorized(session); if (r < 0) { log_warning("Client is not authorized"); *code = mhd_respond(connection, MHD_HTTP_UNAUTHORIZED, "Client certificate not signed by recognized authority"); } return r; } #else int check_permissions(struct MHD_Connection *connection, int *code, char **hostname) { return -EPERM; } int setup_gnutls_logger(char **categories) { if (categories) log_notice("Ignoring specified gnutls logging categories — gnutls not available."); return 0; } #endif