/*
   GSS-PROXY

   Copyright (C) 2012 Red Hat, Inc.
   Copyright (C) 2012 Simo Sorce <simo.sorce@redhat.com>

   Permission is hereby granted, free of charge, to any person obtaining a
   copy of this software and associated documentation files (the "Software"),
   to deal in the Software without restriction, including without limitation
   the rights to use, copy, modify, merge, publish, distribute, sublicense,
   and/or sell copies of the Software, and to permit persons to whom the
   Software is furnished to do so, subject to the following conditions:

   The above copyright notice and this permission notice shall be included in
   all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   DEALINGS IN THE SOFTWARE.
*/


#include "gss_plugin.h"

static OM_uint32 acquire_local(OM_uint32 *minor_status,
                               struct gpp_name_handle *name,
                               OM_uint32 time_req,
                               const gss_OID_set desired_mechs,
                               gss_cred_usage_t cred_usage,
                               struct gpp_cred_handle *out_cred_handle,
                               gss_OID_set *actual_mechs,
                               OM_uint32 *time_rec)
{
    gss_OID_set special_mechs = GSS_C_NO_OID_SET;
    OM_uint32 maj, min;

    special_mechs = gpp_special_available_mechs(desired_mechs);
    if (special_mechs == GSS_C_NO_OID_SET) {
        maj = GSS_S_BAD_MECH;
        min = 0;
        goto done;
    }

    if (name && name->remote && !name->local) {
        maj = gpp_name_to_local(&min, name->remote,
                                name->mech_type, &name->local);
        if (maj) {
            goto done;
        }
    }

    maj = gss_acquire_cred(&min,
                           name ? name->local : NULL,
                           time_req,
                           special_mechs,
                           cred_usage,
                           &out_cred_handle->local,
                           actual_mechs,
                           time_rec);

done:
    *minor_status = min;
    (void)gss_release_oid_set(&min, &special_mechs);
    return maj;
}

OM_uint32 gssi_acquire_cred(OM_uint32 *minor_status,
                            const gss_name_t desired_name,
                            OM_uint32 time_req,
                            const gss_OID_set desired_mechs,
                            gss_cred_usage_t cred_usage,
                            gss_cred_id_t *output_cred_handle,
                            gss_OID_set *actual_mechs,
                            OM_uint32 *time_rec)
{
    enum gpp_behavior behavior;
    struct gpp_name_handle *name;
    struct gpp_cred_handle *out_cred_handle = NULL;
    OM_uint32 maj, min;
    OM_uint32 tmaj, tmin;

    GSSI_TRACE();

    if (!output_cred_handle) {
        *minor_status = gpp_map_error(EINVAL);
        return GSS_S_FAILURE;
    }

    tmaj = GSS_S_COMPLETE;
    tmin = 0;

    out_cred_handle = calloc(1, sizeof(struct gpp_cred_handle));
    if (!out_cred_handle) {
        maj = GSS_S_FAILURE;
        min = ENOMEM;
        goto done;
    }

    name = (struct gpp_name_handle *)desired_name;
    behavior = gpp_get_behavior();

    /* See if we should try local first */
    if (behavior == GPP_LOCAL_ONLY || behavior == GPP_LOCAL_FIRST) {

        maj = acquire_local(&min, name, time_req, desired_mechs, cred_usage,
                            out_cred_handle, actual_mechs, time_rec);

        if (maj == GSS_S_COMPLETE || behavior == GPP_LOCAL_ONLY) {
            goto done;
        }

        /* not successful, save actual local error if remote fallback fails */
        tmaj = maj;
        tmin = min;
    }

    /* Then try with remote */
    if (name && name->local && !name->remote) {
        maj = gpp_local_to_name(&min, name->local, &name->remote);
        if (maj) {
            goto done;
        }
    }

    maj = gpm_acquire_cred(&min,
                           name ? name->remote : NULL,
                           time_req,
                           desired_mechs,
                           cred_usage,
                           &out_cred_handle->remote,
                           actual_mechs,
                           time_rec);
    if (maj == GSS_S_COMPLETE || behavior == GPP_REMOTE_ONLY) {
        goto done;
    }

    if (behavior == GPP_REMOTE_FIRST) {
        /* So remote failed, but we can fallback to local, try that */
        maj = acquire_local(&min, name, time_req, desired_mechs, cred_usage,
                            out_cred_handle, actual_mechs, time_rec);
    }

done:
    if (maj != GSS_S_COMPLETE &&
        maj != GSS_S_CONTINUE_NEEDED &&
        tmaj != GSS_S_COMPLETE) {
        maj = tmaj;
        min = tmin;
    }
    if (maj == GSS_S_COMPLETE) {
        *output_cred_handle = (gss_cred_id_t)out_cred_handle;
    } else {
        free(out_cred_handle);
    }
    *minor_status = gpp_map_error(min);
    return maj;
}

OM_uint32 gssi_add_cred(OM_uint32 *minor_status,
                        const gss_cred_id_t input_cred_handle,
                        const gss_name_t desired_name,
                        const gss_OID desired_mech,
                        gss_cred_usage_t cred_usage,
                        OM_uint32 initiator_time_req,
                        OM_uint32 acceptor_time_req,
                        gss_cred_id_t *output_cred_handle,
                        gss_OID_set *actual_mechs,
                        OM_uint32 *initiator_time_rec,
                        OM_uint32 *acceptor_time_rec)
{
    gss_OID_set desired_mechs = GSS_C_NO_OID_SET;
    OM_uint32 time_req, time_rec;
    OM_uint32 maj, min;

    GSSI_TRACE();

    if (!output_cred_handle) {
        return GSS_S_CALL_INACCESSIBLE_WRITE;
    }

    if (desired_mech) {
        maj = gss_create_empty_oid_set(&min, &desired_mechs);
        if (maj != GSS_S_COMPLETE) {
            *minor_status = gpp_map_error(min);
            return maj;
        }
        maj = gss_add_oid_set_member(&min, desired_mech, &desired_mechs);
        if (maj != GSS_S_COMPLETE) {
            (void)gss_release_oid_set(&min, &desired_mechs);
            *minor_status = gpp_map_error(min);
            return maj;
        }
    }

    switch (cred_usage) {
    case GSS_C_ACCEPT:
        time_req = acceptor_time_req;
        break;
    case GSS_C_INITIATE:
        time_req = initiator_time_req;
        break;
    case GSS_C_BOTH:
        if (acceptor_time_req > initiator_time_req) {
            time_req = acceptor_time_req;
        } else {
            time_req = initiator_time_req;
        }
        break;
    default:
        time_req = 0;
    }

    maj = gssi_acquire_cred(minor_status,
                            desired_name,
                            time_req,
                            desired_mechs,
                            cred_usage,
                            output_cred_handle,
                            actual_mechs,
                            &time_rec);
    if (maj == GSS_S_COMPLETE) {
        if (acceptor_time_rec &&
            (cred_usage == GSS_C_ACCEPT || cred_usage == GSS_C_BOTH)) {
            *acceptor_time_rec = time_rec;
        }
        if (initiator_time_rec &&
            (cred_usage == GSS_C_INITIATE || cred_usage == GSS_C_BOTH)) {
            *initiator_time_rec = time_rec;
        }
    }

    (void)gss_release_oid_set(&min, &desired_mechs);
    return maj;
}

OM_uint32 gssi_acquire_cred_with_password(OM_uint32 *minor_status,
                                          const gss_name_t desired_name,
                                          const gss_buffer_t password,
                                          OM_uint32 time_req,
                                          const gss_OID_set desired_mechs,
                                          gss_cred_usage_t cred_usage,
                                          gss_cred_id_t *output_cred_handle,
                                          gss_OID_set *actual_mechs,
                                          OM_uint32 *time_rec)
{
    enum gpp_behavior behavior;
    struct gpp_name_handle *name;
    struct gpp_cred_handle *out_cred_handle = NULL;
    gss_OID_set special_mechs;
    OM_uint32 maj, min;

    GSSI_TRACE();

    if (desired_name == GSS_C_NO_NAME) {
        *minor_status = gpp_map_error(EINVAL);
        return GSS_S_BAD_NAME;
    }
    name = (struct gpp_name_handle *)desired_name;

    if (!output_cred_handle) {
        *minor_status = gpp_map_error(EINVAL);
        return GSS_S_FAILURE;
    }

    if (desired_mechs == GSS_C_NO_OID_SET) {
        return GSS_S_CALL_INACCESSIBLE_READ;
    }

    behavior = gpp_get_behavior();

    out_cred_handle = calloc(1, sizeof(struct gpp_cred_handle));
    if (!out_cred_handle) {
        *minor_status = gpp_map_error(ENOMEM);
        return GSS_S_FAILURE;
    }

    switch (behavior) {
    case GPP_LOCAL_ONLY:
    case GPP_LOCAL_FIRST:
    case GPP_REMOTE_FIRST:

        /* re-enter the mechglue, using the special OIDs for skipping
         * the use of the interposer */
        special_mechs = gpp_special_available_mechs(desired_mechs);
        if (special_mechs == GSS_C_NO_OID_SET) {
            min = EINVAL;
            maj = GSS_S_FAILURE;
            goto done;
        }

        if (name->remote && !name->local) {
            maj = gpp_name_to_local(&min, name->remote,
                                    name->mech_type, &name->local);
            if (maj) {
                goto done;
            }
        }

        maj = gss_acquire_cred_with_password(&min,
                                             name->local,
                                             password,
                                             time_req,
                                             special_mechs,
                                             cred_usage,
                                             &out_cred_handle->local,
                                             actual_mechs,
                                             time_rec);
        break;
        /* fall through if we got no creds locally and we are in
         * automatic mode */

    case GPP_REMOTE_ONLY:

        /* FIXME: not currently available */

        /* fall through for now */

    default:
        maj = GSS_S_FAILURE;
        min = EINVAL;
    }

done:
    if (maj == GSS_S_COMPLETE) {
        *output_cred_handle = (gss_cred_id_t)out_cred_handle;
    } else {
        free(out_cred_handle);
    }
    *minor_status = gpp_map_error(min);
    (void)gss_release_oid_set(&min, &special_mechs);
    return maj;
}