source: vendor/current/auth/gensec/gensec.c

/*
   Unix SMB/CIFS implementation.

   Generic Authentication Interface

   Copyright (C) Andrew Tridgell 2003
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2006

   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 "system/network.h"
#define TEVENT_DEPRECATED 1
#include <tevent.h>
#include "lib/tsocket/tsocket.h"
#include "lib/util/tevent_ntstatus.h"
#include "auth/gensec/gensec.h"
#include "auth/gensec/gensec_internal.h"
#include "librpc/gen_ndr/dcerpc.h"

_PRIVATE_ NTSTATUS gensec_may_reset_crypto(struct gensec_security *gensec_security,
                                           bool full_reset)
{
        if (!gensec_security->ops->may_reset_crypto) {
                return NT_STATUS_OK;
        }

        return gensec_security->ops->may_reset_crypto(gensec_security, full_reset);
}

/*
  wrappers for the gensec function pointers
*/
_PUBLIC_ NTSTATUS gensec_unseal_packet(struct gensec_security *gensec_security,
                              uint8_t *data, size_t length,
                              const uint8_t *whole_pdu, size_t pdu_length,
                              const DATA_BLOB *sig)
{
        if (!gensec_security->ops->unseal_packet) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_DCE_STYLE)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        return gensec_security->ops->unseal_packet(gensec_security,
                                                   data, length,
                                                   whole_pdu, pdu_length,
                                                   sig);
}

_PUBLIC_ NTSTATUS gensec_check_packet(struct gensec_security *gensec_security,
                             const uint8_t *data, size_t length,
                             const uint8_t *whole_pdu, size_t pdu_length,
                             const DATA_BLOB *sig)
{
        if (!gensec_security->ops->check_packet) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        return gensec_security->ops->check_packet(gensec_security, data, length, whole_pdu, pdu_length, sig);
}

_PUBLIC_ NTSTATUS gensec_seal_packet(struct gensec_security *gensec_security,
                            TALLOC_CTX *mem_ctx,
                            uint8_t *data, size_t length,
                            const uint8_t *whole_pdu, size_t pdu_length,
                            DATA_BLOB *sig)
{
        if (!gensec_security->ops->seal_packet) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_DCE_STYLE)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        return gensec_security->ops->seal_packet(gensec_security, mem_ctx, data, length, whole_pdu, pdu_length, sig);
}

_PUBLIC_ NTSTATUS gensec_sign_packet(struct gensec_security *gensec_security,
                            TALLOC_CTX *mem_ctx,
                            const uint8_t *data, size_t length,
                            const uint8_t *whole_pdu, size_t pdu_length,
                            DATA_BLOB *sig)
{
        if (!gensec_security->ops->sign_packet) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        return gensec_security->ops->sign_packet(gensec_security, mem_ctx, data, length, whole_pdu, pdu_length, sig);
}

_PUBLIC_ size_t gensec_sig_size(struct gensec_security *gensec_security, size_t data_size)
{
        if (!gensec_security->ops->sig_size) {
                return 0;
        }
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                return 0;
        }
        if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
                if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_DCE_STYLE)) {
                        return 0;
                }
        }

        return gensec_security->ops->sig_size(gensec_security, data_size);
}

_PUBLIC_ size_t gensec_max_wrapped_size(struct gensec_security *gensec_security)
{
        if (!gensec_security->ops->max_wrapped_size) {
                return (1 << 17);
        }

        return gensec_security->ops->max_wrapped_size(gensec_security);
}

_PUBLIC_ size_t gensec_max_input_size(struct gensec_security *gensec_security)
{
        if (!gensec_security->ops->max_input_size) {
                return (1 << 17) - gensec_sig_size(gensec_security, 1 << 17);
        }

        return gensec_security->ops->max_input_size(gensec_security);
}

_PUBLIC_ NTSTATUS gensec_wrap(struct gensec_security *gensec_security,
                     TALLOC_CTX *mem_ctx,
                     const DATA_BLOB *in,
                     DATA_BLOB *out)
{
        if (!gensec_security->ops->wrap) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        return gensec_security->ops->wrap(gensec_security, mem_ctx, in, out);
}

_PUBLIC_ NTSTATUS gensec_unwrap(struct gensec_security *gensec_security,
                       TALLOC_CTX *mem_ctx,
                       const DATA_BLOB *in,
                       DATA_BLOB *out)
{
        if (!gensec_security->ops->unwrap) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        return gensec_security->ops->unwrap(gensec_security, mem_ctx, in, out);
}

_PUBLIC_ NTSTATUS gensec_session_key(struct gensec_security *gensec_security,
                                     TALLOC_CTX *mem_ctx,
                                     DATA_BLOB *session_key)
{
        if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SESSION_KEY)) {
                return NT_STATUS_NO_USER_SESSION_KEY;
        }

        if (!gensec_security->ops->session_key) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }

        return gensec_security->ops->session_key(gensec_security, mem_ctx, session_key);
}

/**
 * Return the credentials of a logged on user, including session keys
 * etc.
 *
 * Only valid after a successful authentication
 *
 * May only be called once per authentication.
 *
 */

_PUBLIC_ NTSTATUS gensec_session_info(struct gensec_security *gensec_security,
                                      TALLOC_CTX *mem_ctx,
                                      struct auth_session_info **session_info)
{
        if (!gensec_security->ops->session_info) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }
        return gensec_security->ops->session_info(gensec_security, mem_ctx, session_info);
}

_PUBLIC_ void gensec_set_max_update_size(struct gensec_security *gensec_security,
                                uint32_t max_update_size)
{
        gensec_security->max_update_size = max_update_size;
}

_PUBLIC_ size_t gensec_max_update_size(struct gensec_security *gensec_security)
{
        if (gensec_security->max_update_size == 0) {
                return UINT32_MAX;
        }

        return gensec_security->max_update_size;
}

static NTSTATUS gensec_verify_dcerpc_auth_level(struct gensec_security *gensec_security)
{
        if (gensec_security->dcerpc_auth_level == 0) {
                return NT_STATUS_OK;
        }

        /*
         * Because callers using the
         * gensec_start_mech_by_auth_type() never call
         * gensec_want_feature(), it isn't sensible for them
         * to have to call gensec_have_feature() manually, and
         * these are not points of negotiation, but are
         * asserted by the client
         */
        switch (gensec_security->dcerpc_auth_level) {
        case DCERPC_AUTH_LEVEL_INTEGRITY:
                if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                        DEBUG(0,("Did not manage to negotiate mandetory feature "
                                 "SIGN for dcerpc auth_level %u\n",
                                 gensec_security->dcerpc_auth_level));
                        return NT_STATUS_ACCESS_DENIED;
                }
                break;
        case DCERPC_AUTH_LEVEL_PRIVACY:
                if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
                        DEBUG(0,("Did not manage to negotiate mandetory feature "
                                 "SIGN for dcerpc auth_level %u\n",
                                 gensec_security->dcerpc_auth_level));
                        return NT_STATUS_ACCESS_DENIED;
                }
                if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
                        DEBUG(0,("Did not manage to negotiate mandetory feature "
                                 "SEAL for dcerpc auth_level %u\n",
                                 gensec_security->dcerpc_auth_level));
                        return NT_STATUS_ACCESS_DENIED;
                }
                break;
        default:
                break;
        }

        return NT_STATUS_OK;
}

_PUBLIC_ NTSTATUS gensec_update_ev(struct gensec_security *gensec_security,
                                   TALLOC_CTX *out_mem_ctx,
                                   struct tevent_context *ev,
                                   const DATA_BLOB in, DATA_BLOB *out)
{
        NTSTATUS status;
        const struct gensec_security_ops *ops = gensec_security->ops;
        TALLOC_CTX *frame = NULL;
        struct tevent_req *subreq = NULL;
        bool ok;

        if (ops->update_send == NULL) {

                if (ev == NULL) {
                        frame = talloc_stackframe();

                        ev = samba_tevent_context_init(frame);
                        if (ev == NULL) {
                                status = NT_STATUS_NO_MEMORY;
                                goto fail;
                        }

                        /*
                         * TODO: remove this hack once the backends
                         * are fixed.
                         */
                        tevent_loop_allow_nesting(ev);
                }

                status = ops->update(gensec_security, out_mem_ctx,
                                     ev, in, out);
                TALLOC_FREE(frame);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }

                /*
                 * Because callers using the
                 * gensec_start_mech_by_auth_type() never call
                 * gensec_want_feature(), it isn't sensible for them
                 * to have to call gensec_have_feature() manually, and
                 * these are not points of negotiation, but are
                 * asserted by the client
                 */
                status = gensec_verify_dcerpc_auth_level(gensec_security);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }

                return NT_STATUS_OK;
        }

        frame = talloc_stackframe();

        if (ev == NULL) {
                ev = samba_tevent_context_init(frame);
                if (ev == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto fail;
                }

                /*
                 * TODO: remove this hack once the backends
                 * are fixed.
                 */
                tevent_loop_allow_nesting(ev);
        }

        subreq = ops->update_send(frame, ev, gensec_security, in);
        if (subreq == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto fail;
        }
        ok = tevent_req_poll_ntstatus(subreq, ev, &status);
        if (!ok) {
                goto fail;
        }
        status = ops->update_recv(subreq, out_mem_ctx, out);
 fail:
        TALLOC_FREE(frame);
        return status;
}

/**
 * Next state function for the GENSEC state machine
 *
 * @param gensec_security GENSEC State
 * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 * @param in The request, as a DATA_BLOB
 * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 *                or NT_STATUS_OK if the user is authenticated.
 */

_PUBLIC_ NTSTATUS gensec_update(struct gensec_security *gensec_security,
                                TALLOC_CTX *out_mem_ctx,
                                const DATA_BLOB in, DATA_BLOB *out)
{
        return gensec_update_ev(gensec_security, out_mem_ctx, NULL, in, out);
}

struct gensec_update_state {
        const struct gensec_security_ops *ops;
        struct tevent_req *subreq;
        struct gensec_security *gensec_security;
        DATA_BLOB out;

        /*
         * only for sync backends, we should remove this
         * once all backends are async.
         */
        struct tevent_immediate *im;
        DATA_BLOB in;
};

static void gensec_update_async_trigger(struct tevent_context *ctx,
                                        struct tevent_immediate *im,
                                        void *private_data);
static void gensec_update_subreq_done(struct tevent_req *subreq);

/**
 * Next state function for the GENSEC state machine async version
 *
 * @param mem_ctx The memory context for the request
 * @param ev The event context for the request
 * @param gensec_security GENSEC State
 * @param in The request, as a DATA_BLOB
 *
 * @return The request handle or NULL on no memory failure
 */

_PUBLIC_ struct tevent_req *gensec_update_send(TALLOC_CTX *mem_ctx,
                                               struct tevent_context *ev,
                                               struct gensec_security *gensec_security,
                                               const DATA_BLOB in)
{
        struct tevent_req *req;
        struct gensec_update_state *state = NULL;

        req = tevent_req_create(mem_ctx, &state,
                                struct gensec_update_state);
        if (req == NULL) {
                return NULL;
        }

        state->ops = gensec_security->ops;
        state->gensec_security = gensec_security;

        if (state->ops->update_send == NULL) {
                state->in = in;
                state->im = tevent_create_immediate(state);
                if (tevent_req_nomem(state->im, req)) {
                        return tevent_req_post(req, ev);
                }

                tevent_schedule_immediate(state->im, ev,
                                          gensec_update_async_trigger,
                                          req);

                return req;
        }

        state->subreq = state->ops->update_send(state, ev, gensec_security, in);
        if (tevent_req_nomem(state->subreq, req)) {
                return tevent_req_post(req, ev);
        }

        tevent_req_set_callback(state->subreq,
                                gensec_update_subreq_done,
                                req);

        return req;
}

static void gensec_update_async_trigger(struct tevent_context *ctx,
                                        struct tevent_immediate *im,
                                        void *private_data)
{
        struct tevent_req *req =
                talloc_get_type_abort(private_data, struct tevent_req);
        struct gensec_update_state *state =
                tevent_req_data(req, struct gensec_update_state);
        NTSTATUS status;

        status = state->ops->update(state->gensec_security, state, ctx,
                                    state->in, &state->out);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        tevent_req_done(req);
}

static void gensec_update_subreq_done(struct tevent_req *subreq)
{
        struct tevent_req *req =
                tevent_req_callback_data(subreq,
                struct tevent_req);
        struct gensec_update_state *state =
                tevent_req_data(req,
                struct gensec_update_state);
        NTSTATUS status;

        state->subreq = NULL;

        status = state->ops->update_recv(subreq, state, &state->out);
        TALLOC_FREE(subreq);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        /*
         * Because callers using the
         * gensec_start_mech_by_authtype() never call
         * gensec_want_feature(), it isn't sensible for them
         * to have to call gensec_have_feature() manually, and
         * these are not points of negotiation, but are
         * asserted by the client
         */
        status = gensec_verify_dcerpc_auth_level(state->gensec_security);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        tevent_req_done(req);
}

/**
 * Next state function for the GENSEC state machine
 *
 * @param req request state
 * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 *                or NT_STATUS_OK if the user is authenticated.
 */
_PUBLIC_ NTSTATUS gensec_update_recv(struct tevent_req *req,
                                     TALLOC_CTX *out_mem_ctx,
                                     DATA_BLOB *out)
{
        struct gensec_update_state *state =
                tevent_req_data(req, struct gensec_update_state);
        NTSTATUS status;

        if (tevent_req_is_nterror(req, &status)) {
                if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
                        tevent_req_received(req);
                        return status;
                }
        } else {
                status = NT_STATUS_OK;
        }

        *out = state->out;
        talloc_steal(out_mem_ctx, out->data);

        tevent_req_received(req);
        return status;
}

/**
 * Set the requirement for a certain feature on the connection
 *
 */

_PUBLIC_ void gensec_want_feature(struct gensec_security *gensec_security,
                         uint32_t feature)
{
        if (!gensec_security->ops || !gensec_security->ops->want_feature) {
                gensec_security->want_features |= feature;
                return;
        }
        gensec_security->ops->want_feature(gensec_security, feature);
}

/**
 * Check the requirement for a certain feature on the connection
 *
 */

_PUBLIC_ bool gensec_have_feature(struct gensec_security *gensec_security,
                         uint32_t feature)
{
        if (!gensec_security->ops || !gensec_security->ops->have_feature) {
                return false;
        }

        /* We might 'have' features that we don't 'want', because the
         * other end demanded them, or we can't neotiate them off */
        return gensec_security->ops->have_feature(gensec_security, feature);
}

_PUBLIC_ NTTIME gensec_expire_time(struct gensec_security *gensec_security)
{
        if (!gensec_security->ops->expire_time) {
                return GENSEC_EXPIRE_TIME_INFINITY;
        }

        return gensec_security->ops->expire_time(gensec_security);
}
/**
 * Return the credentials structure associated with a GENSEC context
 *
 */

_PUBLIC_ struct cli_credentials *gensec_get_credentials(struct gensec_security *gensec_security)
{
        if (!gensec_security) {
                return NULL;
        }
        return gensec_security->credentials;
}

/**
 * Set the target service (such as 'http' or 'host') on a GENSEC context - ensures it is talloc()ed
 *
 */

_PUBLIC_ NTSTATUS gensec_set_target_service(struct gensec_security *gensec_security, const char *service)
{
        gensec_security->target.service = talloc_strdup(gensec_security, service);
        if (!gensec_security->target.service) {
                return NT_STATUS_NO_MEMORY;
        }
        return NT_STATUS_OK;
}

_PUBLIC_ const char *gensec_get_target_service(struct gensec_security *gensec_security)
{
        if (gensec_security->target.service) {
                return gensec_security->target.service;
        }

        return "host";
}

/**
 * Set the target hostname (suitable for kerberos resolutation) on a GENSEC context - ensures it is talloc()ed
 *
 */

_PUBLIC_ NTSTATUS gensec_set_target_hostname(struct gensec_security *gensec_security, const char *hostname)
{
        gensec_security->target.hostname = talloc_strdup(gensec_security, hostname);
        if (hostname && !gensec_security->target.hostname) {
                return NT_STATUS_NO_MEMORY;
        }
        return NT_STATUS_OK;
}

_PUBLIC_ const char *gensec_get_target_hostname(struct gensec_security *gensec_security)
{
        /* We allow the target hostname to be overriden for testing purposes */
        if (gensec_security->settings->target_hostname) {
                return gensec_security->settings->target_hostname;
        }

        if (gensec_security->target.hostname) {
                return gensec_security->target.hostname;
        }

        /* We could add use the 'set sockaddr' call, and do a reverse
         * lookup, but this would be both insecure (compromising the
         * way kerberos works) and add DNS timeouts */
        return NULL;
}

/**
 * Set (and copy) local and peer socket addresses onto a socket
 * context on the GENSEC context.
 *
 * This is so that kerberos can include these addresses in
 * cryptographic tokens, to avoid certain attacks.
 */

/**
 * @brief Set the local gensec address.
 *
 * @param  gensec_security   The gensec security context to use.
 *
 * @param  remote       The local address to set.
 *
 * @return              On success NT_STATUS_OK is returned or an NT_STATUS
 *                      error.
 */
_PUBLIC_ NTSTATUS gensec_set_local_address(struct gensec_security *gensec_security,
                const struct tsocket_address *local)
{
        TALLOC_FREE(gensec_security->local_addr);

        if (local == NULL) {
                return NT_STATUS_OK;
        }

        gensec_security->local_addr = tsocket_address_copy(local, gensec_security);
        if (gensec_security->local_addr == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        return NT_STATUS_OK;
}

/**
 * @brief Set the remote gensec address.
 *
 * @param  gensec_security   The gensec security context to use.
 *
 * @param  remote       The remote address to set.
 *
 * @return              On success NT_STATUS_OK is returned or an NT_STATUS
 *                      error.
 */
_PUBLIC_ NTSTATUS gensec_set_remote_address(struct gensec_security *gensec_security,
                const struct tsocket_address *remote)
{
        TALLOC_FREE(gensec_security->remote_addr);

        if (remote == NULL) {
                return NT_STATUS_OK;
        }

        gensec_security->remote_addr = tsocket_address_copy(remote, gensec_security);
        if (gensec_security->remote_addr == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        return NT_STATUS_OK;
}

/**
 * @brief Get the local address from a gensec security context.
 *
 * @param  gensec_security   The security context to get the address from.
 *
 * @return              The address as tsocket_address which could be NULL if
 *                      no address is set.
 */
_PUBLIC_ const struct tsocket_address *gensec_get_local_address(struct gensec_security *gensec_security)
{
        if (gensec_security == NULL) {
                return NULL;
        }
        return gensec_security->local_addr;
}

/**
 * @brief Get the remote address from a gensec security context.
 *
 * @param  gensec_security   The security context to get the address from.
 *
 * @return              The address as tsocket_address which could be NULL if
 *                      no address is set.
 */
_PUBLIC_ const struct tsocket_address *gensec_get_remote_address(struct gensec_security *gensec_security)
{
        if (gensec_security == NULL) {
                return NULL;
        }
        return gensec_security->remote_addr;
}

/**
 * Set the target principal (assuming it it known, say from the SPNEGO reply)
 *  - ensures it is talloc()ed
 *
 */

_PUBLIC_ NTSTATUS gensec_set_target_principal(struct gensec_security *gensec_security, const char *principal)
{
        gensec_security->target.principal = talloc_strdup(gensec_security, principal);
        if (!gensec_security->target.principal) {
                return NT_STATUS_NO_MEMORY;
        }
        return NT_STATUS_OK;
}

_PUBLIC_ const char *gensec_get_target_principal(struct gensec_security *gensec_security)
{
        if (gensec_security->target.principal) {
                return gensec_security->target.principal;
        }

        return NULL;
}