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Diffstat (limited to 'src/journal-remote/microhttpd-util.c')
| -rw-r--r-- | src/journal-remote/microhttpd-util.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/src/journal-remote/microhttpd-util.c b/src/journal-remote/microhttpd-util.c new file mode 100644 index 0000000..c1e35b7 --- /dev/null +++ b/src/journal-remote/microhttpd-util.c @@ -0,0 +1,295 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <stddef.h> +#include <stdio.h> + +#if HAVE_GNUTLS +#include <gnutls/gnutls.h> +#include <gnutls/x509.h> +#endif + +#include "alloc-util.h" +#include "log.h" +#include "macro.h" +#include "microhttpd-util.h" +#include "string-util.h" +#include "strv.h" + +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; +} + +int mhd_respond_internal( + struct MHD_Connection *connection, + enum MHD_RequestTerminationCode code, + const char *buffer, + size_t size, + enum MHD_ResponseMemoryMode mode) { + + assert(connection); + + _cleanup_(MHD_destroy_responsep) struct MHD_Response *response + = MHD_create_response_from_buffer(size, (char*) buffer, mode); + if (!response) + return MHD_NO; + + log_debug("Queueing response %u: %s", code, buffer); + if (MHD_add_response_header(response, "Content-Type", "text/plain") == MHD_NO) + return MHD_NO; + return MHD_queue_response(connection, code, response); +} + +int mhd_respond_oom(struct MHD_Connection *connection) { + return mhd_respond(connection, MHD_HTTP_SERVICE_UNAVAILABLE, "Out of memory."); +} + +int mhd_respondf_internal( + struct MHD_Connection *connection, + int error, + enum MHD_RequestTerminationCode code, + const char *format, ...) { + + char *m; + int r; + va_list ap; + + assert(connection); + assert(format); + + if (error < 0) + error = -error; + errno = -error; + 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); +} + +#if 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; + } + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "No such log category: %s", cat); +} + +int setup_gnutls_logger(char **categories) { + 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) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Failed to retrieve certificate chain"); + + 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 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 = TAKE_PTR(buf); + + 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 +_noreturn_ int check_permissions(struct MHD_Connection *connection, int *code, char **hostname) { + assert_not_reached(); +} + +int setup_gnutls_logger(char **categories) { + if (categories) + log_notice("Ignoring specified gnutls logging categories — gnutls not available."); + return 0; +} +#endif |