heimdal/lib/krb5/kcm.c

/*
 * Copyright (c) 2005, PADL Software Pty Ltd.
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of PADL Software nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "krb5_locl.h"

#ifdef HAVE_KCM
/*
 * Client library for Kerberos Credentials Manager (KCM) daemon
 */

#include "kcm.h"
#include <heim-ipc.h>

static krb5_error_code
kcm_set_kdc_offset(krb5_context, krb5_ccache, krb5_deltat);

static const char *kcm_ipc_name = "ANY:org.h5l.kcm";

typedef struct krb5_kcmcache {
    char *name;
} krb5_kcmcache;

typedef struct krb5_kcm_cursor {
    unsigned long offset;
    unsigned long length;
    kcmuuid_t *uuids;
} *krb5_kcm_cursor;


#define KCMCACHE(X)	((krb5_kcmcache *)(X)->data.data)
#define CACHENAME(X)	(KCMCACHE(X)->name)
#define KCMCURSOR(C)	((krb5_kcm_cursor)(C))

static HEIMDAL_MUTEX kcm_mutex = HEIMDAL_MUTEX_INITIALIZER;
static heim_ipc kcm_ipc = NULL;

static krb5_error_code
kcm_send_request(krb5_context context,
		 krb5_storage *request,
		 krb5_data *response_data)
{
    krb5_error_code ret = 0;
    krb5_data request_data;

    krb5_data_zero(response_data);

    HEIMDAL_MUTEX_lock(&kcm_mutex);
    if (kcm_ipc == NULL)
	ret = heim_ipc_init_context(kcm_ipc_name, &kcm_ipc);
    HEIMDAL_MUTEX_unlock(&kcm_mutex);
    if (ret)
	return KRB5_CC_NOSUPP;

    ret = krb5_storage_to_data(request, &request_data);
    if (ret) {
	return krb5_enomem(context);
    }

    ret = heim_ipc_call(kcm_ipc, &request_data, response_data, NULL);
    krb5_data_free(&request_data);
    return ret;
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kcm_storage_request(krb5_context context,
			 uint16_t opcode,
			 krb5_storage **storage_p)
{
    krb5_storage *sp;
    krb5_error_code ret;

    *storage_p = NULL;

    sp = krb5_storage_emem();
    if (sp == NULL)
	return krb5_enomem(context);

    /* Send MAJOR | VERSION | OPCODE */
    ret  = krb5_store_int8(sp, KCM_PROTOCOL_VERSION_MAJOR);
    if (ret)
	goto fail;
    ret = krb5_store_int8(sp, KCM_PROTOCOL_VERSION_MINOR);
    if (ret)
	goto fail;
    ret = krb5_store_int16(sp, opcode);
    if (ret)
	goto fail;

    *storage_p = sp;
 fail:
    if (ret) {
	krb5_set_error_message(context, ret,
			       N_("Failed to encode KCM request", ""));
	krb5_storage_free(sp);
    }

    return ret;
}

/*
 * A sort of a state() for caches -- we use this to see if the local default
 * cache name for KCM happens to exist.  See kcm_alloc() below.
 */
static krb5_error_code
kcm_stat(krb5_context context, const char *name)
{
    krb5_error_code ret;
    krb5_storage *request = NULL;
    krb5_data response_data;

    krb5_data_zero(&response_data);

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_PRINCIPAL, &request);
    if (ret == 0)
        ret = krb5_store_stringz(request, name);
    if (ret == 0)
        ret = krb5_kcm_call(context, request, NULL, &response_data);
    krb5_storage_free(request);
    krb5_data_free(&response_data);
    return ret;
}

static krb5_error_code kcm_get_default_name(krb5_context,
                                            const krb5_cc_ops *,
                                            const char *, char **);

static krb5_error_code
kcm_alloc(krb5_context context,
          const krb5_cc_ops *ops,
          const char *residual,
          const char *sub,
          krb5_ccache *id)
{
    krb5_error_code ret;
    krb5_kcmcache *k;
    size_t ops_prefix_len = strlen(ops->prefix);
    size_t plen = 0;
    size_t local_def_name_len;
    char *local_def_name = NULL; /* Our idea of default KCM cache name */
    char *kcm_def_name = NULL; /* KCM's knowledge of default cache name */
    int aret;

    /* Get the KCM:%{UID} default */
    if (ops == &krb5_kcm_ops)
        ret = _krb5_expand_default_cc_name(context, KRB5_DEFAULT_CCNAME_KCM_KCM, &local_def_name);
    else
        ret = _krb5_expand_default_cc_name(context, KRB5_DEFAULT_CCNAME_KCM_API, &local_def_name);
    if (ret)
        return ret;
    local_def_name_len = strlen(local_def_name);

    /* Get the default ccache name from KCM if possible */
    (void) kcm_get_default_name(context, ops, NULL, &kcm_def_name);

    /*
     * We have a sticky situation in that applications that call
     * krb5_cc_default() will be getting the locally configured or compiled-in
     * default KCM cache name, which may not exist in the user's KCM session,
     * and which the KCM daemon may not be able to alias to the actual default
     * for the user's session.
     *
     * To deal with this we heuristically detect when an application uses the
     * default KCM ccache name.
     *
     * If the residual happens to be the local default KCM name we may end up
     * using whatever the default KCM cache name is instead of the local
     * default.
     *
     * Note that here `residual' may be any of:
     *
     *  - %{UID}
     *  - %{UID}:
     *  - %{UID}:<subsidiary>
     *  - <something not starting with %{UID}:>
     *  - <empty string>
     *  - <NULL>
     *
     * Only the first two count as "maybe I mean the default KCM cache".
     */
    if (residual && !sub &&
        strncmp(residual, local_def_name + ops_prefix_len + 1,
                local_def_name_len - (ops_prefix_len + 1)) == 0) {
        if (residual[local_def_name_len - (ops_prefix_len + 1)] == '\0' ||
            (residual[local_def_name_len - (ops_prefix_len + 1)] == ':' &&
             residual[local_def_name_len - ops_prefix_len] == '\0')) {
            /*
             * If we got a default cache name from KCM and the requested default
             * cache does not exist, use the former.
             */
            if (kcm_def_name && kcm_stat(context, residual))
                residual = kcm_def_name + ops_prefix_len + 1;
        }
    }

    if (residual && residual[0] == '\0')
        residual = NULL;
    if (sub && sub[0] == '\0')
        sub = NULL;

    if (residual == NULL && sub == NULL) {
        /* Use the default cache name, either from KCM or local default */
        if (kcm_def_name)
            residual = kcm_def_name + ops_prefix_len + 1;
        else
            residual = local_def_name + ops_prefix_len + 1;
    }

    if (residual) {
        /* KCM cache names must start with {UID} or {UID}: */
        if (residual[0] != '0')
            plen = strspn(residual, "0123456789");
        if (plen && residual[plen] != ':' && residual[plen] != '\0')
            plen = 0;
        /*
         * If `plen', then residual is such a residual, else we'll want to
         * prefix the {UID}:.
         */
    }

    k = calloc(1, sizeof(*k));
    if (k == NULL) {
        free(local_def_name);
        free(kcm_def_name);
	return krb5_enomem(context);
    }
    k->name = NULL;

    if (residual == NULL && sub == NULL) {
        /* One more way to get a default */
        aret = asprintf(&k->name, "%llu", (unsigned long long)getuid());
    } else if (residual == NULL) {
        /*
         * Treat the subsidiary as the residual (maybe this will turn out to be
         * wrong).
         */
        aret = asprintf(&k->name, "%llu:%s", (unsigned long long)getuid(),
                        sub);
    } else if (plen) {
        /* The residual is a UID */
        aret = asprintf(&k->name, "%s%s%s", residual,
                        sub ? ":" : "", sub ? sub : "");
    } else if (sub == NULL) {
        /* The residual is NOT a UID */
        aret = asprintf(&k->name, "%llu:%s", (unsigned long long)getuid(),
                        residual);
    } else {
        /* Ditto, plus we have a subsidiary.  `residual && sub && !plen' */
        aret = asprintf(&k->name, "%llu:%s:%s", (unsigned long long)getuid(),
                        residual, sub);
    }
    if (aret == -1 || k->name == NULL) {
        free(local_def_name);
        free(kcm_def_name);
        free(k);
        return krb5_enomem(context);
    }

    free(local_def_name);
    free(kcm_def_name);
    (*id)->data.data = k;
    (*id)->data.length = sizeof(*k);

    return 0;
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_kcm_call(krb5_context context,
	      krb5_storage *request,
	      krb5_storage **response_p,
	      krb5_data *response_data_p)
{
    krb5_data response_data;
    krb5_error_code ret;
    int32_t status;
    krb5_storage *response;

    if (response_p != NULL)
	*response_p = NULL;

    krb5_data_zero(&response_data);
    ret = kcm_send_request(context, request, &response_data);
    if (ret) {
        krb5_data_free(&response_data);
        return ret;
    }

    response = krb5_storage_from_data(&response_data);
    if (response == NULL) {
	krb5_data_free(&response_data);
	return KRB5_CC_IO;
    }

    ret = krb5_ret_int32(response, &status);
    if (ret) {
	krb5_storage_free(response);
	krb5_data_free(&response_data);
	return KRB5_CC_FORMAT;
    }

    if (status) {
	krb5_storage_free(response);
	krb5_data_free(&response_data);
	return status;
    }

    if (response_p != NULL) {
	*response_data_p = response_data;
	*response_p = response;

	return 0;
    }

    krb5_storage_free(response);
    krb5_data_free(&response_data);

    return 0;
}

static void
kcm_free(krb5_context context, krb5_ccache *id)
{
    krb5_kcmcache *k = KCMCACHE(*id);

    if (k != NULL) {
	if (k->name != NULL)
	    free(k->name);
	memset_s(k, sizeof(*k), 0, sizeof(*k));
	krb5_data_free(&(*id)->data);
    }
}

static krb5_error_code KRB5_CALLCONV
kcm_get_name_2(krb5_context context,
	       krb5_ccache id,
	       const char **name,
	       const char **col,
	       const char **sub)
{
    /*
     * TODO:
     *
     *  - name should be <IPC-name>:<cache-name>
     *  - col  should be <IPC-name>
     *  - sub  should be <cache-name>
     */
    if (name)
        *name = CACHENAME(id);
    if (col)
        *col = NULL;
    if (sub)
        *sub = CACHENAME(id);
    return 0;
}

static krb5_error_code
kcm_resolve_2_kcm(krb5_context context,
                  krb5_ccache *id,
                  const char *res,
                  const char *sub)
{
    /*
     * For now, for KCM the `res' is the `sub'.
     *
     * TODO: We should use `res' as the IPC name instead of the one currently
     *       hard-coded in `kcm_ipc_name'.
     */
    return kcm_alloc(context, &krb5_kcm_ops, res, sub, id);
}

static krb5_error_code
kcm_resolve_2_api(krb5_context context,
                  krb5_ccache *id,
                  const char *res,
                  const char *sub)
{
    /*
     * For now, for KCM the `res' is the `sub'.
     *
     * TODO: We should use `res' as the IPC name instead of the one currently
     *       hard-coded in `kcm_ipc_name'.
     */
    return kcm_alloc(context, &krb5_akcm_ops, res, sub, id);
}

/*
 * Request:
 *
 * Response:
 *      NameZ
 */
static krb5_error_code
kcm_gen_new(krb5_context context, const krb5_cc_ops *ops, krb5_ccache *id)
{
    krb5_kcmcache *k;
    krb5_error_code ret;
    krb5_storage *request, *response;
    krb5_data response_data;

    ret = kcm_alloc(context, ops, NULL, NULL, id);
    if (ret)
	return ret;

    k = KCMCACHE(*id);

    ret = krb5_kcm_storage_request(context, KCM_OP_GEN_NEW, &request);
    if (ret) {
	kcm_free(context, id);
	return ret;
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    if (ret) {
	krb5_storage_free(request);
	kcm_free(context, id);
	return ret;
    }

    ret = krb5_ret_stringz(response, &k->name);
    if (ret)
	ret = KRB5_CC_IO;

    krb5_storage_free(request);
    krb5_storage_free(response);
    krb5_data_free(&response_data);

    if (ret)
	kcm_free(context, id);

    return ret;
}

static krb5_error_code
kcm_gen_new_kcm(krb5_context context, krb5_ccache *id)
{
    return kcm_gen_new(context, &krb5_kcm_ops, id);
}

static krb5_error_code
kcm_gen_new_api(krb5_context context, krb5_ccache *id)
{
    return kcm_gen_new(context, &krb5_akcm_ops, id);
}

/*
 * Request:
 *      NameZ
 *      Principal
 *
 * Response:
 *
 */
static krb5_error_code
kcm_initialize(krb5_context context,
	       krb5_ccache id,
	       krb5_principal primary_principal)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_INITIALIZE, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_principal(request, primary_principal);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);

    if (context->kdc_sec_offset)
	kcm_set_kdc_offset(context, id, context->kdc_sec_offset);

    return ret;
}

static krb5_error_code
kcm_close(krb5_context context,
	  krb5_ccache id)
{
    kcm_free(context, &id);
    return 0;
}

/*
 * Request:
 *      NameZ
 *
 * Response:
 *
 */
static krb5_error_code
kcm_destroy(krb5_context context,
	    krb5_ccache id)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_DESTROY, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}

/*
 * Request:
 *      NameZ
 *      Creds
 *
 * Response:
 *
 */
static krb5_error_code
kcm_store_cred(krb5_context context,
	       krb5_ccache id,
	       krb5_creds *creds)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_STORE, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_creds(request, creds);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}

#if 0
/*
 * Request:
 *      NameZ
 *      WhichFields
 *      MatchCreds
 *
 * Response:
 *      Creds
 *
 */
static krb5_error_code
kcm_retrieve(krb5_context context,
	     krb5_ccache id,
	     krb5_flags which,
	     const krb5_creds *mcred,
	     krb5_creds *creds)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request, *response;
    krb5_data response_data;

    ret = krb5_kcm_storage_request(context, KCM_OP_RETRIEVE, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_int32(request, which);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_creds_tag(request, rk_UNCONST(mcred));
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_ret_creds(response, creds);
    if (ret)
	ret = KRB5_CC_IO;

    krb5_storage_free(request);
    krb5_storage_free(response);
    krb5_data_free(&response_data);

    return ret;
}
#endif

/*
 * Request:
 *      NameZ
 *
 * Response:
 *      Principal
 */
static krb5_error_code
kcm_get_principal(krb5_context context,
		  krb5_ccache id,
		  krb5_principal *principal)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request, *response;
    krb5_data response_data;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_PRINCIPAL, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_ret_principal(response, principal);
    if (ret)
	ret = KRB5_CC_IO;

    krb5_storage_free(request);
    krb5_storage_free(response);
    krb5_data_free(&response_data);

    return ret;
}

/*
 * Request:
 *      NameZ
 *
 * Response:
 *      Cursor
 *
 */
static krb5_error_code
kcm_get_first (krb5_context context,
	       krb5_ccache id,
	       krb5_cc_cursor *cursor)
{
    krb5_error_code ret;
    krb5_kcm_cursor c;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request, *response;
    krb5_data response_data;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_CRED_UUID_LIST, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    krb5_storage_free(request);
    if (ret)
	return ret;

    c = calloc(1, sizeof(*c));
    if (c == NULL) {
	ret = krb5_enomem(context);
	return ret;
    }

    while (1) {
	ssize_t sret;
	kcmuuid_t uuid;
	void *ptr;

	sret = krb5_storage_read(response, &uuid, sizeof(uuid));
	if (sret == 0) {
	    ret = 0;
	    break;
	} else if (sret != sizeof(uuid)) {
	    ret = EINVAL;
	    break;
	}

	ptr = realloc(c->uuids, sizeof(c->uuids[0]) * (c->length + 1));
	if (ptr == NULL) {
	    free(c->uuids);
	    free(c);
	    return krb5_enomem(context);
	}
	c->uuids = ptr;

	memcpy(&c->uuids[c->length], &uuid, sizeof(uuid));
	c->length += 1;
    }

    krb5_storage_free(response);
    krb5_data_free(&response_data);

    if (ret) {
        free(c->uuids);
        free(c);
	return ret;
    }

    *cursor = c;

    return 0;
}

/*
 * Request:
 *      NameZ
 *      Cursor
 *
 * Response:
 *      Creds
 */
static krb5_error_code
kcm_get_next (krb5_context context,
		krb5_ccache id,
		krb5_cc_cursor *cursor,
		krb5_creds *creds)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_kcm_cursor c = KCMCURSOR(*cursor);
    krb5_storage *request, *response;
    krb5_data response_data;
    ssize_t sret;

 again:

    if (c->offset >= c->length)
	return KRB5_CC_END;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_CRED_BY_UUID, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    sret = krb5_storage_write(request,
			      &c->uuids[c->offset],
			      sizeof(c->uuids[c->offset]));
    c->offset++;
    if (sret != sizeof(c->uuids[c->offset])) {
	krb5_storage_free(request);
	return krb5_enomem(context);
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    krb5_storage_free(request);
    if (ret == KRB5_CC_END) {
	goto again;
    } else if (ret)
	return ret;

    ret = krb5_ret_creds(response, creds);
    if (ret)
	ret = KRB5_CC_IO;

    krb5_storage_free(response);
    krb5_data_free(&response_data);

    return ret;
}

/*
 * Request:
 *      NameZ
 *      Cursor
 *
 * Response:
 *
 */
static krb5_error_code
kcm_end_get (krb5_context context,
	     krb5_ccache id,
	     krb5_cc_cursor *cursor)
{
    krb5_kcm_cursor c = KCMCURSOR(*cursor);

    free(c->uuids);
    free(c);

    *cursor = NULL;

    return 0;
}

/*
 * Request:
 *      NameZ
 *      WhichFields
 *      MatchCreds
 *
 * Response:
 *
 */
static krb5_error_code
kcm_remove_cred(krb5_context context,
		krb5_ccache id,
		krb5_flags which,
		krb5_creds *cred)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_REMOVE_CRED, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_int32(request, which);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_creds_tag(request, cred);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}

static krb5_error_code
kcm_set_flags(krb5_context context,
	      krb5_ccache id,
	      krb5_flags flags)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_SET_FLAGS, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_int32(request, flags);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}

static int
kcm_get_version(krb5_context context,
		krb5_ccache id)
{
    return 0;
}

/*
 * Send nothing
 * get back list of uuids
 */

static krb5_error_code
kcm_get_cache_first(krb5_context context, krb5_cc_cursor *cursor)
{
    krb5_error_code ret;
    krb5_kcm_cursor c;
    krb5_storage *request, *response;
    krb5_data response_data;

    *cursor = NULL;

    c = calloc(1, sizeof(*c));
    if (c == NULL) {
	ret = krb5_enomem(context);
	goto out;
    }

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_CACHE_UUID_LIST, &request);
    if (ret)
	goto out;

    ret = krb5_kcm_call(context, request, &response, &response_data);
    krb5_storage_free(request);
    if (ret)
	goto out;

    while (1) {
	ssize_t sret;
	kcmuuid_t uuid;
	void *ptr;

	sret = krb5_storage_read(response, &uuid, sizeof(uuid));
	if (sret == 0) {
	    ret = 0;
	    break;
	} else if (sret != sizeof(uuid)) {
	    ret = EINVAL;
	    goto out;
	}

	ptr = realloc(c->uuids, sizeof(c->uuids[0]) * (c->length + 1));
	if (ptr == NULL) {
	    ret = krb5_enomem(context);
	    goto out;
	}
	c->uuids = ptr;

	memcpy(&c->uuids[c->length], &uuid, sizeof(uuid));
	c->length += 1;
    }

    krb5_storage_free(response);
    krb5_data_free(&response_data);

 out:
    if (ret && c) {
        free(c->uuids);
        free(c);
    } else
	*cursor = c;

    return ret;
}

/*
 * Send uuid
 * Recv cache name
 */

static krb5_error_code
kcm_get_cache_next(krb5_context context, krb5_cc_cursor cursor, const krb5_cc_ops *ops, krb5_ccache *id)
{
    krb5_error_code ret;
    krb5_kcm_cursor c = KCMCURSOR(cursor);
    krb5_storage *request, *response;
    krb5_data response_data;
    ssize_t sret;
    char *name;

    *id = NULL;

 again:

    if (c->offset >= c->length)
	return KRB5_CC_END;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_CACHE_BY_UUID, &request);
    if (ret)
	return ret;

    sret = krb5_storage_write(request,
			      &c->uuids[c->offset],
			      sizeof(c->uuids[c->offset]));
    c->offset++;
    if (sret != sizeof(c->uuids[c->offset])) {
	krb5_storage_free(request);
	return krb5_enomem(context);
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    krb5_storage_free(request);
    if (ret == KRB5_CC_END)
	goto again;
    else if (ret)
	return ret;

    ret = krb5_ret_stringz(response, &name);
    krb5_storage_free(response);
    krb5_data_free(&response_data);

    if (ret == 0) {
	ret = _krb5_cc_allocate(context, ops, id);
	if (ret == 0)
	    ret = kcm_alloc(context, ops, name, NULL, id);
	krb5_xfree(name);
    }

    return ret;
}

static krb5_error_code
kcm_get_cache_next_kcm(krb5_context context, krb5_cc_cursor cursor, krb5_ccache *id)
{
#ifndef KCM_IS_API_CACHE
    return kcm_get_cache_next(context, cursor, &krb5_kcm_ops, id);
#else
    return KRB5_CC_END;
#endif
}

static krb5_error_code
kcm_get_cache_next_api(krb5_context context, krb5_cc_cursor cursor, krb5_ccache *id)
{
    return kcm_get_cache_next(context, cursor, &krb5_akcm_ops, id);
}


static krb5_error_code
kcm_end_cache_get(krb5_context context, krb5_cc_cursor cursor)
{
    krb5_kcm_cursor c = KCMCURSOR(cursor);

    free(c->uuids);
    free(c);
    return 0;
}


static krb5_error_code
kcm_move(krb5_context context, krb5_ccache from, krb5_ccache to)
{
    krb5_error_code ret;
    krb5_kcmcache *oldk = KCMCACHE(from);
    krb5_kcmcache *newk = KCMCACHE(to);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_MOVE_CACHE, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, oldk->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_stringz(request, newk->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }
    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);

    if (ret == 0)
        krb5_cc_destroy(context, from);
    return ret;
}

static krb5_error_code
kcm_get_default_name(krb5_context context, const krb5_cc_ops *ops,
		     const char *defstr, char **str)
{
    krb5_error_code ret;
    krb5_storage *request, *response;
    krb5_data response_data;
    char *name;
    int aret;

    *str = NULL;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_DEFAULT_CACHE, &request);
    if (ret)
	return ret;

    ret = krb5_kcm_call(context, request, &response, &response_data);
    krb5_storage_free(request);
    if (ret) {
        if (defstr)
            return _krb5_expand_default_cc_name(context, defstr, str);
        return ret;
    }

    ret = krb5_ret_stringz(response, &name);
    krb5_storage_free(response);
    krb5_data_free(&response_data);
    if (ret)
	return ret;

    aret = asprintf(str, "%s:%s", ops->prefix, name);
    free(name);
    if (aret == -1 || *str == NULL)
	return krb5_enomem(context);

    return 0;
}

static krb5_error_code
kcm_get_default_name_api(krb5_context context, char **str)
{
    return kcm_get_default_name(context, &krb5_akcm_ops,
				KRB5_DEFAULT_CCNAME_KCM_API, str);
}

static krb5_error_code
kcm_get_default_name_kcm(krb5_context context, char **str)
{
    return kcm_get_default_name(context, &krb5_kcm_ops,
				KRB5_DEFAULT_CCNAME_KCM_KCM, str);
}

static krb5_error_code
kcm_set_default(krb5_context context, krb5_ccache id)
{
    krb5_error_code ret;
    krb5_storage *request;
    krb5_kcmcache *k = KCMCACHE(id);

    ret = krb5_kcm_storage_request(context, KCM_OP_SET_DEFAULT_CACHE, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);
    krb5_storage_free(request);

    return ret;
}

static krb5_error_code
kcm_lastchange(krb5_context context, krb5_ccache id, krb5_timestamp *mtime)
{
    *mtime = time(NULL);
    return 0;
}

static krb5_error_code
kcm_set_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat kdc_offset)
{
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_error_code ret;
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_SET_KDC_OFFSET, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }
    ret = krb5_store_int32(request, kdc_offset);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);
    krb5_storage_free(request);

    return ret;
}

static krb5_error_code
kcm_get_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat *kdc_offset)
{
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_error_code ret;
    krb5_storage *request, *response;
    krb5_data response_data;
    int32_t offset;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_KDC_OFFSET, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, &response, &response_data);
    krb5_storage_free(request);
    if (ret)
	return ret;

    ret = krb5_ret_int32(response, &offset);
    krb5_storage_free(response);
    krb5_data_free(&response_data);
    if (ret)
	return ret;

    *kdc_offset = offset;

    return 0;
}

/**
 * Variable containing the KCM based credential cache implemention.
 *
 * @ingroup krb5_ccache
 */

KRB5_LIB_VARIABLE const krb5_cc_ops krb5_kcm_ops = {
    KRB5_CC_OPS_VERSION_5,
    "KCM",
    NULL,
    NULL,
    kcm_gen_new_kcm,
    kcm_initialize,
    kcm_destroy,
    kcm_close,
    kcm_store_cred,
    NULL /* kcm_retrieve */,
    kcm_get_principal,
    kcm_get_first,
    kcm_get_next,
    kcm_end_get,
    kcm_remove_cred,
    kcm_set_flags,
    kcm_get_version,
    kcm_get_cache_first,
    kcm_get_cache_next_kcm,
    kcm_end_cache_get,
    kcm_move,
    kcm_get_default_name_kcm,
    kcm_set_default,
    kcm_lastchange,
    kcm_set_kdc_offset,
    kcm_get_kdc_offset,
    kcm_get_name_2,
    kcm_resolve_2_kcm
};

KRB5_LIB_VARIABLE const krb5_cc_ops krb5_akcm_ops = {
    KRB5_CC_OPS_VERSION_5,
    "API",
    NULL,
    NULL,
    kcm_gen_new_api,
    kcm_initialize,
    kcm_destroy,
    kcm_close,
    kcm_store_cred,
    NULL /* kcm_retrieve */,
    kcm_get_principal,
    kcm_get_first,
    kcm_get_next,
    kcm_end_get,
    kcm_remove_cred,
    kcm_set_flags,
    kcm_get_version,
    kcm_get_cache_first,
    kcm_get_cache_next_api,
    kcm_end_cache_get,
    kcm_move,
    kcm_get_default_name_api,
    kcm_set_default,
    kcm_lastchange,
    NULL,
    NULL,
    kcm_get_name_2,
    kcm_resolve_2_api
};

KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL
_krb5_kcm_is_running(krb5_context context)
{
    krb5_error_code ret;
    krb5_ccache_data ccdata;
    krb5_ccache id = &ccdata;
    krb5_boolean running;

    ret = kcm_alloc(context, NULL, NULL, NULL, &id);
    if (ret)
	return 0;

    running = (_krb5_kcm_noop(context, id) == 0);

    kcm_free(context, &id);

    return running;
}

/*
 * Request:
 *
 * Response:
 *
 */
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_kcm_noop(krb5_context context,
	       krb5_ccache id)
{
    krb5_error_code ret;
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_NOOP, &request);
    if (ret)
	return ret;

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}


/*
 * Request:
 *      NameZ
 *      ServerPrincipalPresent
 *      ServerPrincipal OPTIONAL
 *      Key
 *
 * Repsonse:
 *
 */
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_kcm_get_initial_ticket(krb5_context context,
			     krb5_ccache id,
			     krb5_principal server,
			     krb5_keyblock *key)
{
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_error_code ret;
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_INITIAL_TICKET, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_int8(request, (server == NULL) ? 0 : 1);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    if (server != NULL) {
	ret = krb5_store_principal(request, server);
	if (ret) {
	    krb5_storage_free(request);
	    return ret;
	}
    }

    ret = krb5_store_keyblock(request, *key);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}


/*
 * Request:
 *      NameZ
 *      KDCFlags
 *      EncryptionType
 *      ServerPrincipal
 *
 * Repsonse:
 *
 */
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_kcm_get_ticket(krb5_context context,
		     krb5_ccache id,
		     krb5_kdc_flags flags,
		     krb5_enctype enctype,
		     krb5_principal server)
{
    krb5_error_code ret;
    krb5_kcmcache *k = KCMCACHE(id);
    krb5_storage *request;

    ret = krb5_kcm_storage_request(context, KCM_OP_GET_TICKET, &request);
    if (ret)
	return ret;

    ret = krb5_store_stringz(request, k->name);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_int32(request, flags.i);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_int32(request, enctype);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_store_principal(request, server);
    if (ret) {
	krb5_storage_free(request);
	return ret;
    }

    ret = krb5_kcm_call(context, request, NULL, NULL);

    krb5_storage_free(request);
    return ret;
}

#endif /* HAVE_KCM */