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Diffstat (limited to '')
| -rw-r--r-- | librpc/rpc/dcesrv_auth.c | 703 |
1 files changed, 703 insertions, 0 deletions
diff --git a/librpc/rpc/dcesrv_auth.c b/librpc/rpc/dcesrv_auth.c new file mode 100644 index 0000000..99d8e01 --- /dev/null +++ b/librpc/rpc/dcesrv_auth.c @@ -0,0 +1,703 @@ +/* + Unix SMB/CIFS implementation. + + server side dcerpc authentication code + + Copyright (C) Andrew Tridgell 2003 + Copyright (C) Stefan (metze) Metzmacher 2004 + + 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 "librpc/rpc/dcesrv_core.h" +#include "librpc/rpc/dcesrv_core_proto.h" +#include "librpc/rpc/dcerpc_util.h" +#include "librpc/rpc/dcerpc_pkt_auth.h" +#include "librpc/gen_ndr/ndr_dcerpc.h" +#include "auth/credentials/credentials.h" +#include "auth/gensec/gensec.h" +#include "auth/auth.h" +#include "param/param.h" + +static NTSTATUS dcesrv_auth_negotiate_hdr_signing(struct dcesrv_call_state *call, + struct ncacn_packet *pkt) +{ + struct dcesrv_connection *dce_conn = call->conn; + struct dcesrv_auth *a = NULL; + + if (!(call->pkt.pfc_flags & DCERPC_PFC_FLAG_SUPPORT_HEADER_SIGN)) { + return NT_STATUS_OK; + } + + if (dce_conn->client_hdr_signing) { + if (dce_conn->negotiated_hdr_signing && pkt != NULL) { + pkt->pfc_flags |= DCERPC_PFC_FLAG_SUPPORT_HEADER_SIGN; + } + return NT_STATUS_OK; + } + + dce_conn->client_hdr_signing = true; + dce_conn->negotiated_hdr_signing = dce_conn->support_hdr_signing; + + if (!dce_conn->negotiated_hdr_signing) { + return NT_STATUS_OK; + } + + if (pkt != NULL) { + pkt->pfc_flags |= DCERPC_PFC_FLAG_SUPPORT_HEADER_SIGN; + } + + a = call->conn->default_auth_state; + if (a->gensec_security != NULL) { + gensec_want_feature(a->gensec_security, + GENSEC_FEATURE_SIGN_PKT_HEADER); + } + + for (a = call->conn->auth_states; a != NULL; a = a->next) { + if (a->gensec_security == NULL) { + continue; + } + + gensec_want_feature(a->gensec_security, + GENSEC_FEATURE_SIGN_PKT_HEADER); + } + + return NT_STATUS_OK; +} + +static bool dcesrv_auth_prepare_gensec(struct dcesrv_call_state *call) +{ + struct dcesrv_connection *dce_conn = call->conn; + struct dcesrv_auth *auth = call->auth_state; + struct dcesrv_context_callbacks *cb = call->conn->dce_ctx->callbacks; + NTSTATUS status; + + if (auth->auth_started) { + return false; + } + + auth->auth_started = true; + + if (auth->auth_invalid) { + return false; + } + + if (auth->auth_finished) { + return false; + } + + if (auth->gensec_security != NULL) { + return false; + } + + switch (call->in_auth_info.auth_level) { + case DCERPC_AUTH_LEVEL_CONNECT: + case DCERPC_AUTH_LEVEL_CALL: + case DCERPC_AUTH_LEVEL_PACKET: + case DCERPC_AUTH_LEVEL_INTEGRITY: + case DCERPC_AUTH_LEVEL_PRIVACY: + /* + * We evaluate auth_type only if auth_level was valid + */ + break; + default: + /* + * Setting DCERPC_AUTH_LEVEL_NONE, + * gives the caller the reject_reason + * as auth_context_id. + * + * Note: DCERPC_AUTH_LEVEL_NONE == 1 + */ + auth->auth_type = DCERPC_AUTH_TYPE_NONE; + auth->auth_level = DCERPC_AUTH_LEVEL_NONE; + auth->auth_context_id = DCERPC_BIND_NAK_REASON_NOT_SPECIFIED; + return false; + } + + auth->auth_type = call->in_auth_info.auth_type; + auth->auth_level = call->in_auth_info.auth_level; + auth->auth_context_id = call->in_auth_info.auth_context_id; + + cb->auth.become_root(); + status = cb->auth.gensec_prepare( + auth, + call, + &auth->gensec_security, + cb->auth.private_data); + cb->auth.unbecome_root(); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("Failed to call samba_server_gensec_start %s\n", + nt_errstr(status))); + return false; + } + + /* + * We have to call this because we set the target_service for + * Kerberos to NULL above, and in any case we wish to log a + * more specific service target. + * + */ + status = gensec_set_target_service_description(auth->gensec_security, + "DCE/RPC"); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("Failed to call gensec_set_target_service_description %s\n", + nt_errstr(status))); + return false; + } + + if (call->conn->remote_address != NULL) { + status = gensec_set_remote_address(auth->gensec_security, + call->conn->remote_address); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("Failed to call gensec_set_remote_address() %s\n", + nt_errstr(status))); + return false; + } + } + + if (call->conn->local_address != NULL) { + status = gensec_set_local_address(auth->gensec_security, + call->conn->local_address); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("Failed to call gensec_set_local_address() %s\n", + nt_errstr(status))); + return false; + } + } + + status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_type, + auth->auth_level); + if (!NT_STATUS_IS_OK(status)) { + const char *backend_name = + gensec_get_name_by_authtype(auth->gensec_security, + auth->auth_type); + + DEBUG(3, ("Failed to start GENSEC mechanism for DCERPC server: " + "auth_type=%d (%s), auth_level=%d: %s\n", + (int)auth->auth_type, backend_name, + (int)auth->auth_level, + nt_errstr(status))); + + /* + * Setting DCERPC_AUTH_LEVEL_NONE, + * gives the caller the reject_reason + * as auth_context_id. + * + * Note: DCERPC_AUTH_LEVEL_NONE == 1 + */ + auth->auth_type = DCERPC_AUTH_TYPE_NONE; + auth->auth_level = DCERPC_AUTH_LEVEL_NONE; + if (backend_name != NULL) { + auth->auth_context_id = + DCERPC_BIND_NAK_REASON_INVALID_CHECKSUM; + } else { + auth->auth_context_id = + DCERPC_BIND_NAK_REASON_INVALID_AUTH_TYPE; + } + return false; + } + + if (dce_conn->negotiated_hdr_signing) { + gensec_want_feature(auth->gensec_security, + GENSEC_FEATURE_SIGN_PKT_HEADER); + } + + return true; +} + +static void dcesrv_default_auth_state_finish_bind(struct dcesrv_call_state *call) +{ + SMB_ASSERT(call->pkt.ptype == DCERPC_PKT_BIND); + + if (call->auth_state == call->conn->default_auth_state) { + return; + } + + if (call->conn->default_auth_state->auth_started) { + return; + } + + if (call->conn->default_auth_state->auth_invalid) { + return; + } + + call->conn->default_auth_state->auth_type = DCERPC_AUTH_TYPE_NONE; + call->conn->default_auth_state->auth_level = DCERPC_AUTH_LEVEL_NONE; + call->conn->default_auth_state->auth_context_id = 0; + call->conn->default_auth_state->auth_started = true; + call->conn->default_auth_state->auth_finished = true; + + /* + * + * We defer log_successful_dcesrv_authz_event() + * to dcesrv_default_auth_state_prepare_request() + * + * As we don't want to trigger authz_events + * just for alter_context requests without authentication + */ +} + +void dcesrv_default_auth_state_prepare_request(struct dcesrv_call_state *call) +{ + struct dcesrv_connection *dce_conn = call->conn; + struct dcesrv_auth *auth = call->auth_state; + struct dcesrv_context_callbacks *cb = call->conn->dce_ctx->callbacks; + + if (auth->auth_audited) { + return; + } + + if (call->pkt.ptype != DCERPC_PKT_REQUEST) { + return; + } + + if (auth != dce_conn->default_auth_state) { + return; + } + + if (auth->auth_invalid) { + return; + } + + if (!auth->auth_finished) { + return; + } + + if (cb->log.successful_authz == NULL) { + return; + } + + cb->log.successful_authz(call, cb->log.private_data); +} + +/* + parse any auth information from a dcerpc bind request + return false if we can't handle the auth request for some + reason (in which case we send a bind_nak) +*/ +bool dcesrv_auth_bind(struct dcesrv_call_state *call) +{ + struct ncacn_packet *pkt = &call->pkt; + struct dcesrv_auth *auth = call->auth_state; + struct dcesrv_context_callbacks *cb = call->conn->dce_ctx->callbacks; + NTSTATUS status; + + if (pkt->auth_length == 0) { + auth->auth_type = DCERPC_AUTH_TYPE_NONE; + auth->auth_level = DCERPC_AUTH_LEVEL_NONE; + auth->auth_context_id = 0; + auth->auth_started = true; + + if (cb->log.successful_authz != NULL) { + cb->log.successful_authz(call, cb->log.private_data); + } + + return true; + } + + status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.bind.auth_info, + &call->in_auth_info, + NULL, true); + if (!NT_STATUS_IS_OK(status)) { + /* + * Setting DCERPC_AUTH_LEVEL_NONE, + * gives the caller the reject_reason + * as auth_context_id. + * + * Note: DCERPC_AUTH_LEVEL_NONE == 1 + */ + auth->auth_type = DCERPC_AUTH_TYPE_NONE; + auth->auth_level = DCERPC_AUTH_LEVEL_NONE; + auth->auth_context_id = + DCERPC_BIND_NAK_REASON_PROTOCOL_VERSION_NOT_SUPPORTED; + return false; + } + + return dcesrv_auth_prepare_gensec(call); +} + +NTSTATUS dcesrv_auth_complete(struct dcesrv_call_state *call, NTSTATUS status) +{ + struct dcesrv_auth *auth = call->auth_state; + struct dcesrv_context_callbacks *cb = call->conn->dce_ctx->callbacks; + const char *pdu = "<unknown>"; + + switch (call->pkt.ptype) { + case DCERPC_PKT_BIND: + pdu = "BIND"; + break; + case DCERPC_PKT_ALTER: + pdu = "ALTER"; + break; + case DCERPC_PKT_AUTH3: + pdu = "AUTH3"; + if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { + DEBUG(4, ("GENSEC not finished at at %s\n", pdu)); + return NT_STATUS_RPC_SEC_PKG_ERROR; + } + break; + default: + return NT_STATUS_INTERNAL_ERROR; + } + + if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { + return NT_STATUS_OK; + } + + if (!NT_STATUS_IS_OK(status)) { + DEBUG(4, ("GENSEC mech rejected the incoming authentication " + "at %s: %s\n", pdu, nt_errstr(status))); + return status; + } + + cb->auth.become_root(); + status = gensec_session_info(auth->gensec_security, + auth, + &auth->session_info); + cb->auth.unbecome_root(); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("Failed to establish session_info: %s\n", + nt_errstr(status))); + return status; + } + auth->auth_finished = true; + + if (auth->auth_level == DCERPC_AUTH_LEVEL_CONNECT && + !call->conn->got_explicit_auth_level_connect) + { + call->conn->default_auth_level_connect = auth; + } + + if (call->pkt.ptype != DCERPC_PKT_AUTH3) { + return NT_STATUS_OK; + } + + if (call->out_auth_info->credentials.length != 0) { + DEBUG(4, ("GENSEC produced output token (len=%zu) at %s\n", + call->out_auth_info->credentials.length, pdu)); + return NT_STATUS_RPC_SEC_PKG_ERROR; + } + + return NT_STATUS_OK; +} + +/* + add any auth information needed in a bind ack, and process the authentication + information found in the bind. +*/ +NTSTATUS dcesrv_auth_prepare_bind_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt) +{ + struct dcesrv_connection *dce_conn = call->conn; + struct dcesrv_auth *auth = call->auth_state; + NTSTATUS status; + + status = dcesrv_auth_negotiate_hdr_signing(call, pkt); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + dce_conn->allow_alter = true; + dcesrv_default_auth_state_finish_bind(call); + + if (call->pkt.auth_length == 0) { + auth->auth_finished = true; + return NT_STATUS_OK; + } + + /* We can't work without an existing gensec state */ + if (auth->gensec_security == NULL) { + return NT_STATUS_INTERNAL_ERROR; + } + + call->_out_auth_info = (struct dcerpc_auth) { + .auth_type = auth->auth_type, + .auth_level = auth->auth_level, + .auth_context_id = auth->auth_context_id, + }; + call->out_auth_info = &call->_out_auth_info; + + return NT_STATUS_OK; +} + +/* + process the final stage of a auth request +*/ +bool dcesrv_auth_prepare_auth3(struct dcesrv_call_state *call) +{ + struct ncacn_packet *pkt = &call->pkt; + struct dcesrv_auth *auth = call->auth_state; + NTSTATUS status; + + if (pkt->auth_length == 0) { + return false; + } + + if (auth->auth_finished) { + return false; + } + + if (auth->auth_invalid) { + return false; + } + + /* We can't work without an existing gensec state */ + if (auth->gensec_security == NULL) { + return false; + } + + status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.auth3.auth_info, + &call->in_auth_info, NULL, true); + if (!NT_STATUS_IS_OK(status)) { + /* + * Windows returns DCERPC_NCA_S_FAULT_REMOTE_NO_MEMORY + * instead of DCERPC_NCA_S_PROTO_ERROR. + */ + call->fault_code = DCERPC_NCA_S_FAULT_REMOTE_NO_MEMORY; + return false; + } + + if (call->in_auth_info.auth_type != auth->auth_type) { + return false; + } + + if (call->in_auth_info.auth_level != auth->auth_level) { + return false; + } + + if (call->in_auth_info.auth_context_id != auth->auth_context_id) { + return false; + } + + call->_out_auth_info = (struct dcerpc_auth) { + .auth_type = auth->auth_type, + .auth_level = auth->auth_level, + .auth_context_id = auth->auth_context_id, + }; + call->out_auth_info = &call->_out_auth_info; + + return true; +} + +/* + parse any auth information from a dcerpc alter request + return false if we can't handle the auth request for some + reason (in which case we send a bind_nak (is this true for here?)) +*/ +bool dcesrv_auth_alter(struct dcesrv_call_state *call) +{ + struct ncacn_packet *pkt = &call->pkt; + struct dcesrv_auth *auth = call->auth_state; + NTSTATUS status; + + /* on a pure interface change there is no auth blob */ + if (pkt->auth_length == 0) { + if (!auth->auth_finished) { + return false; + } + return true; + } + + if (auth->auth_finished) { + call->fault_code = DCERPC_FAULT_ACCESS_DENIED; + return false; + } + + status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.alter.auth_info, + &call->in_auth_info, NULL, true); + if (!NT_STATUS_IS_OK(status)) { + call->fault_code = DCERPC_NCA_S_PROTO_ERROR; + return false; + } + + if (!auth->auth_started) { + bool ok; + + ok = dcesrv_auth_prepare_gensec(call); + if (!ok) { + call->fault_code = DCERPC_FAULT_ACCESS_DENIED; + return false; + } + + return true; + } + + if (call->in_auth_info.auth_type == DCERPC_AUTH_TYPE_NONE) { + call->fault_code = DCERPC_FAULT_ACCESS_DENIED; + return false; + } + + if (auth->auth_invalid) { + return false; + } + + if (call->in_auth_info.auth_type != auth->auth_type) { + return false; + } + + if (call->in_auth_info.auth_level != auth->auth_level) { + return false; + } + + if (call->in_auth_info.auth_context_id != auth->auth_context_id) { + return false; + } + + return true; +} + +/* + add any auth information needed in a alter ack, and process the authentication + information found in the alter. +*/ +NTSTATUS dcesrv_auth_prepare_alter_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt) +{ + struct dcesrv_auth *auth = call->auth_state; + NTSTATUS status; + + status = dcesrv_auth_negotiate_hdr_signing(call, pkt); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + /* on a pure interface change there is no auth_info structure + setup */ + if (call->pkt.auth_length == 0) { + return NT_STATUS_OK; + } + + if (auth->gensec_security == NULL) { + return NT_STATUS_INTERNAL_ERROR; + } + + call->_out_auth_info = (struct dcerpc_auth) { + .auth_type = auth->auth_type, + .auth_level = auth->auth_level, + .auth_context_id = auth->auth_context_id, + }; + call->out_auth_info = &call->_out_auth_info; + + return NT_STATUS_OK; +} + +/* + check credentials on a packet +*/ +bool dcesrv_auth_pkt_pull(struct dcesrv_call_state *call, + DATA_BLOB *full_packet, + uint8_t required_flags, + uint8_t optional_flags, + uint8_t payload_offset, + DATA_BLOB *payload_and_verifier) +{ + struct ncacn_packet *pkt = &call->pkt; + struct dcesrv_auth *auth = call->auth_state; + const struct dcerpc_auth tmp_auth = { + .auth_type = auth->auth_type, + .auth_level = auth->auth_level, + .auth_context_id = auth->auth_context_id, + }; + bool check_pkt_auth_fields; + NTSTATUS status; + + if (!auth->auth_started) { + return false; + } + + if (!auth->auth_finished) { + call->fault_code = DCERPC_NCA_S_PROTO_ERROR; + return false; + } + + if (auth->auth_invalid) { + return false; + } + + if (call->pkt.pfc_flags & DCERPC_PFC_FLAG_FIRST) { + /* + * The caller most likely checked this + * already, but we better double check. + */ + check_pkt_auth_fields = true; + } else { + /* + * The caller already found first fragment + * and is passing the auth_state of it. + * A server is supposed to use the + * setting of the first fragment and + * completely ignore the values + * on the remaining fragments + */ + check_pkt_auth_fields = false; + } + + status = dcerpc_ncacn_pull_pkt_auth(&tmp_auth, + auth->gensec_security, + check_pkt_auth_fields, + call, + pkt->ptype, + required_flags, + optional_flags, + payload_offset, + payload_and_verifier, + full_packet, + pkt); + if (NT_STATUS_EQUAL(status, NT_STATUS_RPC_PROTOCOL_ERROR)) { + call->fault_code = DCERPC_NCA_S_PROTO_ERROR; + return false; + } + if (NT_STATUS_EQUAL(status, NT_STATUS_RPC_UNSUPPORTED_AUTHN_LEVEL)) { + call->fault_code = DCERPC_NCA_S_UNSUPPORTED_AUTHN_LEVEL; + return false; + } + if (NT_STATUS_EQUAL(status, NT_STATUS_RPC_SEC_PKG_ERROR)) { + call->fault_code = DCERPC_FAULT_SEC_PKG_ERROR; + return false; + } + if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) { + call->fault_code = DCERPC_FAULT_ACCESS_DENIED; + return false; + } + if (!NT_STATUS_IS_OK(status)) { + return false; + } + + return true; +} + +/* + push a signed or sealed dcerpc request packet into a blob +*/ +bool dcesrv_auth_pkt_push(struct dcesrv_call_state *call, + DATA_BLOB *blob, size_t sig_size, + uint8_t payload_offset, + const DATA_BLOB *payload, + const struct ncacn_packet *pkt) +{ + struct dcesrv_auth *auth = call->auth_state; + const struct dcerpc_auth tmp_auth = { + .auth_type = auth->auth_type, + .auth_level = auth->auth_level, + .auth_context_id = auth->auth_context_id, + }; + NTSTATUS status; + + status = dcerpc_ncacn_push_pkt_auth(&tmp_auth, + auth->gensec_security, + call, blob, sig_size, + payload_offset, + payload, + pkt); + return NT_STATUS_IS_OK(status); +} |