/* Unix SMB/CIFS implementation. transport layer security handling code Copyright (C) Andrew Tridgell 2004-2005 Copyright (C) Stefan Metzmacher 2004 Copyright (C) Andrew Bartlett 2006 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #include "lib/events/events.h" #include "lib/socket/socket.h" #include "lib/tls/tls.h" #include "param/param.h" #if ENABLE_GNUTLS #include "gnutls/gnutls.h" #define DH_BITS 1024 #if defined(HAVE_GNUTLS_DATUM) && !defined(HAVE_GNUTLS_DATUM_T) typedef gnutls_datum gnutls_datum_t; #endif /* hold persistent tls data */ struct tls_params { gnutls_certificate_credentials x509_cred; gnutls_dh_params dh_params; bool tls_enabled; }; #endif /* hold per connection tls data */ struct tls_context { struct socket_context *socket; struct tevent_fd *fde; bool tls_enabled; #if ENABLE_GNUTLS gnutls_session session; bool done_handshake; bool have_first_byte; uint8_t first_byte; bool tls_detect; const char *plain_chars; bool output_pending; gnutls_certificate_credentials xcred; bool interrupted; #endif }; bool tls_enabled(struct socket_context *sock) { struct tls_context *tls; if (!sock) { return false; } if (strcmp(sock->backend_name, "tls") != 0) { return false; } tls = talloc_get_type(sock->private_data, struct tls_context); if (!tls) { return false; } return tls->tls_enabled; } #if ENABLE_GNUTLS static const struct socket_ops tls_socket_ops; static NTSTATUS tls_socket_init(struct socket_context *sock) { switch (sock->type) { case SOCKET_TYPE_STREAM: break; default: return NT_STATUS_INVALID_PARAMETER; } sock->backend_name = "tls"; return NT_STATUS_OK; } #define TLSCHECK(call) do { \ ret = call; \ if (ret < 0) { \ DEBUG(0,("TLS %s - %s\n", #call, gnutls_strerror(ret))); \ goto failed; \ } \ } while (0) /* callback for reading from a socket */ static ssize_t tls_pull(gnutls_transport_ptr ptr, void *buf, size_t size) { struct tls_context *tls = talloc_get_type(ptr, struct tls_context); NTSTATUS status; size_t nread; if (tls->have_first_byte) { *(uint8_t *)buf = tls->first_byte; tls->have_first_byte = false; return 1; } status = socket_recv(tls->socket, buf, size, &nread); if (NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)) { return 0; } if (NT_STATUS_IS_ERR(status)) { EVENT_FD_NOT_READABLE(tls->fde); EVENT_FD_NOT_WRITEABLE(tls->fde); errno = EBADF; return -1; } if (!NT_STATUS_IS_OK(status)) { EVENT_FD_READABLE(tls->fde); errno = EAGAIN; return -1; } if (tls->output_pending) { EVENT_FD_WRITEABLE(tls->fde); } if (size != nread) { EVENT_FD_READABLE(tls->fde); } return nread; } /* callback for writing to a socket */ static ssize_t tls_push(gnutls_transport_ptr ptr, const void *buf, size_t size) { struct tls_context *tls = talloc_get_type(ptr, struct tls_context); NTSTATUS status; size_t nwritten; DATA_BLOB b; if (!tls->tls_enabled) { return size; } b.data = discard_const(buf); b.length = size; status = socket_send(tls->socket, &b, &nwritten); if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) { errno = EAGAIN; return -1; } if (!NT_STATUS_IS_OK(status)) { EVENT_FD_WRITEABLE(tls->fde); return -1; } if (size != nwritten) { EVENT_FD_WRITEABLE(tls->fde); } return nwritten; } /* destroy a tls session */ static int tls_destructor(struct tls_context *tls) { int ret; ret = gnutls_bye(tls->session, GNUTLS_SHUT_WR); if (ret < 0) { DEBUG(4,("TLS gnutls_bye failed - %s\n", gnutls_strerror(ret))); } return 0; } /* possibly continue the handshake process */ static NTSTATUS tls_handshake(struct tls_context *tls) { int ret; if (tls->done_handshake) { return NT_STATUS_OK; } ret = gnutls_handshake(tls->session); if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) { if (gnutls_record_get_direction(tls->session) == 1) { EVENT_FD_WRITEABLE(tls->fde); } return STATUS_MORE_ENTRIES; } if (ret < 0) { DEBUG(0,("TLS gnutls_handshake failed - %s\n", gnutls_strerror(ret))); return NT_STATUS_UNEXPECTED_NETWORK_ERROR; } tls->done_handshake = true; return NT_STATUS_OK; } /* possibly continue an interrupted operation */ static NTSTATUS tls_interrupted(struct tls_context *tls) { int ret; if (!tls->interrupted) { return NT_STATUS_OK; } if (gnutls_record_get_direction(tls->session) == 1) { ret = gnutls_record_send(tls->session, NULL, 0); } else { ret = gnutls_record_recv(tls->session, NULL, 0); } if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) { return STATUS_MORE_ENTRIES; } tls->interrupted = false; return NT_STATUS_OK; } /* see how many bytes are pending on the connection */ static NTSTATUS tls_socket_pending(struct socket_context *sock, size_t *npending) { struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); if (!tls->tls_enabled || tls->tls_detect) { return socket_pending(tls->socket, npending); } *npending = gnutls_record_check_pending(tls->session); if (*npending == 0) { NTSTATUS status = socket_pending(tls->socket, npending); if (*npending == 0) { /* seems to be a gnutls bug */ (*npending) = 100; } return status; } return NT_STATUS_OK; } /* receive data either by tls or normal socket_recv */ static NTSTATUS tls_socket_recv(struct socket_context *sock, void *buf, size_t wantlen, size_t *nread) { int ret; NTSTATUS status; struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); if (tls->tls_enabled && tls->tls_detect) { status = socket_recv(tls->socket, &tls->first_byte, 1, nread); NT_STATUS_NOT_OK_RETURN(status); if (*nread == 0) return NT_STATUS_OK; tls->tls_detect = false; /* look for the first byte of a valid HTTP operation */ if (strchr(tls->plain_chars, tls->first_byte)) { /* not a tls link */ tls->tls_enabled = false; *(uint8_t *)buf = tls->first_byte; return NT_STATUS_OK; } tls->have_first_byte = true; } if (!tls->tls_enabled) { return socket_recv(tls->socket, buf, wantlen, nread); } status = tls_handshake(tls); NT_STATUS_NOT_OK_RETURN(status); status = tls_interrupted(tls); NT_STATUS_NOT_OK_RETURN(status); ret = gnutls_record_recv(tls->session, buf, wantlen); if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) { if (gnutls_record_get_direction(tls->session) == 1) { EVENT_FD_WRITEABLE(tls->fde); } tls->interrupted = true; return STATUS_MORE_ENTRIES; } if (ret < 0) { return NT_STATUS_UNEXPECTED_NETWORK_ERROR; } *nread = ret; return NT_STATUS_OK; } /* send data either by tls or normal socket_recv */ static NTSTATUS tls_socket_send(struct socket_context *sock, const DATA_BLOB *blob, size_t *sendlen) { NTSTATUS status; int ret; struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); if (!tls->tls_enabled) { return socket_send(tls->socket, blob, sendlen); } status = tls_handshake(tls); NT_STATUS_NOT_OK_RETURN(status); status = tls_interrupted(tls); NT_STATUS_NOT_OK_RETURN(status); ret = gnutls_record_send(tls->session, blob->data, blob->length); if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) { if (gnutls_record_get_direction(tls->session) == 1) { EVENT_FD_WRITEABLE(tls->fde); } tls->interrupted = true; return STATUS_MORE_ENTRIES; } if (ret < 0) { DEBUG(0,("gnutls_record_send of %d failed - %s\n", (int)blob->length, gnutls_strerror(ret))); return NT_STATUS_UNEXPECTED_NETWORK_ERROR; } *sendlen = ret; tls->output_pending = (ret < blob->length); return NT_STATUS_OK; } /* initialise global tls state */ struct tls_params *tls_initialise(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx) { struct tls_params *params; int ret; TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx); const char *keyfile = lp_tls_keyfile(tmp_ctx, lp_ctx); const char *certfile = lp_tls_certfile(tmp_ctx, lp_ctx); const char *cafile = lp_tls_cafile(tmp_ctx, lp_ctx); const char *crlfile = lp_tls_crlfile(tmp_ctx, lp_ctx); const char *dhpfile = lp_tls_dhpfile(tmp_ctx, lp_ctx); void tls_cert_generate(TALLOC_CTX *, const char *, const char *, const char *, const char *); params = talloc(mem_ctx, struct tls_params); if (params == NULL) { talloc_free(tmp_ctx); return NULL; } if (!lp_tls_enabled(lp_ctx) || keyfile == NULL || *keyfile == 0) { params->tls_enabled = false; talloc_free(tmp_ctx); return params; } if (!file_exist(cafile)) { char *hostname = talloc_asprintf(mem_ctx, "%s.%s", lp_netbios_name(lp_ctx), lp_realm(lp_ctx)); if (hostname == NULL) { goto init_failed; } tls_cert_generate(params, hostname, keyfile, certfile, cafile); talloc_free(hostname); } ret = gnutls_global_init(); if (ret < 0) goto init_failed; gnutls_certificate_allocate_credentials(¶ms->x509_cred); if (ret < 0) goto init_failed; if (cafile && *cafile) { ret = gnutls_certificate_set_x509_trust_file(params->x509_cred, cafile, GNUTLS_X509_FMT_PEM); if (ret < 0) { DEBUG(0,("TLS failed to initialise cafile %s\n", cafile)); goto init_failed; } } if (crlfile && *crlfile) { ret = gnutls_certificate_set_x509_crl_file(params->x509_cred, crlfile, GNUTLS_X509_FMT_PEM); if (ret < 0) { DEBUG(0,("TLS failed to initialise crlfile %s\n", crlfile)); goto init_failed; } } ret = gnutls_certificate_set_x509_key_file(params->x509_cred, certfile, keyfile, GNUTLS_X509_FMT_PEM); if (ret < 0) { DEBUG(0,("TLS failed to initialise certfile %s and keyfile %s\n", certfile, keyfile)); goto init_failed; } ret = gnutls_dh_params_init(¶ms->dh_params); if (ret < 0) goto init_failed; if (dhpfile && *dhpfile) { gnutls_datum_t dhparms; size_t size; dhparms.data = (uint8_t *)file_load(dhpfile, &size, 0, mem_ctx); if (!dhparms.data) { DEBUG(0,("Failed to read DH Parms from %s\n", dhpfile)); goto init_failed; } dhparms.size = size; ret = gnutls_dh_params_import_pkcs3(params->dh_params, &dhparms, GNUTLS_X509_FMT_PEM); if (ret < 0) goto init_failed; } else { ret = gnutls_dh_params_generate2(params->dh_params, DH_BITS); if (ret < 0) goto init_failed; } gnutls_certificate_set_dh_params(params->x509_cred, params->dh_params); params->tls_enabled = true; talloc_free(tmp_ctx); return params; init_failed: DEBUG(0,("GNUTLS failed to initialise - %s\n", gnutls_strerror(ret))); params->tls_enabled = false; talloc_free(tmp_ctx); return params; } /* setup for a new connection */ struct socket_context *tls_init_server(struct tls_params *params, struct socket_context *socket_ctx, struct tevent_fd *fde, const char *plain_chars) { struct tls_context *tls; int ret; struct socket_context *new_sock; NTSTATUS nt_status; nt_status = socket_create_with_ops(socket_ctx, &tls_socket_ops, &new_sock, SOCKET_TYPE_STREAM, socket_ctx->flags | SOCKET_FLAG_ENCRYPT); if (!NT_STATUS_IS_OK(nt_status)) { return NULL; } tls = talloc(new_sock, struct tls_context); if (tls == NULL) { return NULL; } tls->socket = socket_ctx; talloc_steal(tls, socket_ctx); tls->fde = fde; new_sock->private_data = tls; if (!params->tls_enabled) { talloc_free(new_sock); return NULL; } TLSCHECK(gnutls_init(&tls->session, GNUTLS_SERVER)); talloc_set_destructor(tls, tls_destructor); TLSCHECK(gnutls_set_default_priority(tls->session)); TLSCHECK(gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, params->x509_cred)); gnutls_certificate_server_set_request(tls->session, GNUTLS_CERT_REQUEST); gnutls_dh_set_prime_bits(tls->session, DH_BITS); gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr)tls); gnutls_transport_set_pull_function(tls->session, (gnutls_pull_func)tls_pull); gnutls_transport_set_push_function(tls->session, (gnutls_push_func)tls_push); gnutls_transport_set_lowat(tls->session, 0); tls->plain_chars = plain_chars; if (plain_chars) { tls->tls_detect = true; } else { tls->tls_detect = false; } tls->output_pending = false; tls->done_handshake = false; tls->have_first_byte = false; tls->tls_enabled = true; tls->interrupted = false; new_sock->state = SOCKET_STATE_SERVER_CONNECTED; return new_sock; failed: DEBUG(0,("TLS init connection failed - %s\n", gnutls_strerror(ret))); talloc_free(new_sock); return NULL; } /* setup for a new client connection */ struct socket_context *tls_init_client(struct socket_context *socket_ctx, struct tevent_fd *fde, const char *ca_path) { struct tls_context *tls; int ret = 0; const int cert_type_priority[] = { GNUTLS_CRT_X509, GNUTLS_CRT_OPENPGP, 0 }; struct socket_context *new_sock; NTSTATUS nt_status; nt_status = socket_create_with_ops(socket_ctx, &tls_socket_ops, &new_sock, SOCKET_TYPE_STREAM, socket_ctx->flags | SOCKET_FLAG_ENCRYPT); if (!NT_STATUS_IS_OK(nt_status)) { return NULL; } tls = talloc(new_sock, struct tls_context); if (tls == NULL) return NULL; tls->socket = socket_ctx; talloc_steal(tls, socket_ctx); tls->fde = fde; new_sock->private_data = tls; gnutls_global_init(); gnutls_certificate_allocate_credentials(&tls->xcred); gnutls_certificate_set_x509_trust_file(tls->xcred, ca_path, GNUTLS_X509_FMT_PEM); TLSCHECK(gnutls_init(&tls->session, GNUTLS_CLIENT)); TLSCHECK(gnutls_set_default_priority(tls->session)); gnutls_certificate_type_set_priority(tls->session, cert_type_priority); TLSCHECK(gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, tls->xcred)); talloc_set_destructor(tls, tls_destructor); gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr)tls); gnutls_transport_set_pull_function(tls->session, (gnutls_pull_func)tls_pull); gnutls_transport_set_push_function(tls->session, (gnutls_push_func)tls_push); gnutls_transport_set_lowat(tls->session, 0); tls->tls_detect = false; tls->output_pending = false; tls->done_handshake = false; tls->have_first_byte = false; tls->tls_enabled = true; tls->interrupted = false; new_sock->state = SOCKET_STATE_CLIENT_CONNECTED; return new_sock; failed: DEBUG(0,("TLS init connection failed - %s\n", gnutls_strerror(ret))); tls->tls_enabled = false; return new_sock; } static NTSTATUS tls_socket_set_option(struct socket_context *sock, const char *option, const char *val) { set_socket_options(socket_get_fd(sock), option); return NT_STATUS_OK; } static char *tls_socket_get_peer_name(struct socket_context *sock, TALLOC_CTX *mem_ctx) { struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); return socket_get_peer_name(tls->socket, mem_ctx); } static struct socket_address *tls_socket_get_peer_addr(struct socket_context *sock, TALLOC_CTX *mem_ctx) { struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); return socket_get_peer_addr(tls->socket, mem_ctx); } static struct socket_address *tls_socket_get_my_addr(struct socket_context *sock, TALLOC_CTX *mem_ctx) { struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); return socket_get_my_addr(tls->socket, mem_ctx); } static int tls_socket_get_fd(struct socket_context *sock) { struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context); return socket_get_fd(tls->socket); } static const struct socket_ops tls_socket_ops = { .name = "tls", .fn_init = tls_socket_init, .fn_recv = tls_socket_recv, .fn_send = tls_socket_send, .fn_pending = tls_socket_pending, .fn_set_option = tls_socket_set_option, .fn_get_peer_name = tls_socket_get_peer_name, .fn_get_peer_addr = tls_socket_get_peer_addr, .fn_get_my_addr = tls_socket_get_my_addr, .fn_get_fd = tls_socket_get_fd }; bool tls_support(struct tls_params *params) { return params->tls_enabled; } #else /* for systems without tls we just fail the operations, and the caller * will retain the original socket */ struct tls_params *tls_initialise(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx) { return talloc_new(mem_ctx); } /* setup for a new connection */ struct socket_context *tls_init_server(struct tls_params *params, struct socket_context *socket, struct tevent_fd *fde, const char *plain_chars) { return NULL; } /* setup for a new client connection */ struct socket_context *tls_init_client(struct socket_context *socket, struct tevent_fd *fde, const char *ca_path) { return NULL; } bool tls_support(struct tls_params *params) { return false; } #endif