/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * prof_solaris.c:
 * Abstracted contract private interfaces for configuring krb5.conf(5).
 */

#include <ctype.h>
#include "prof_int.h"
#include "k5-int.h"

errcode_t
__profile_iter_name_value(profile_t profile, char *section, char *key,
        char ***retvals)
{
        const char      *hierarchy[4];
        errcode_t       code, code2;
        char            *name = NULL, *value = NULL, **ret_values = NULL;
        void            *state = NULL;
        struct profile_string_list values;
        boolean_t       found = FALSE;

        hierarchy[0] = section;
        hierarchy[1] = NULL;

        if (code = init_list(&values))
                return (code);

        code = profile_iterator_create(profile, hierarchy,
            PROFILE_ITER_LIST_SECTION, &state);
        while (code == 0) {
                code = profile_iterator(&state, &name, &value);
                if (code == 0 && name != NULL) {
                        if ((key == NULL) || (strcmp(value, key) == 0)) {
                                code2 = add_to_list(&values, name);
                                if (code2 != 0) {
                                        end_list(&values, &ret_values);
                                        profile_free_list(ret_values);
                                        code2 = code;
                                        goto cleanup;
                                }
                                found = TRUE;
                        }
                }
                if (name != NULL) {
                        profile_release_string(name);
                        name = NULL;
                }
                if (value != NULL) {
                        profile_release_string(value);
                        value = NULL;
                }
        }
        code = 0;
        if (found == TRUE)
                end_list(&values, &ret_values);

cleanup:

        if (state != NULL)
                profile_iterator_free(&state);
        if (name != NULL)
                profile_release_string(name);
        if (value != NULL)
                profile_release_string(value);

        *retvals = ret_values;

        return (code);
}

errcode_t
__profile_get_domain_realm(profile_t profile, char *realm, char ***domains)
{
        if (profile == NULL || realm == NULL || domains == NULL)
                return (EINVAL);

        return (__profile_iter_name_value(profile, "domain_realm", realm,
            domains));
}

errcode_t
__profile_set_appdefaults(profile_t profile)
{
        const char      *hierarchy[4];
        errcode_t       code;

        if (profile == NULL)
                return (EINVAL);

        hierarchy[0] = "appdefaults";
        hierarchy[1] = "kinit";
        hierarchy[3] = NULL;

        hierarchy[2] = "renewable";

        /*
         * Not fatal if this fails, continue on.
         */
        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, "true");
        if (code != 0)
                return (code);

        hierarchy[2] = "forwardable";

        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, "true");

        return (code);
}

errcode_t
__profile_set_logging(profile_t profile)
{
        const char      *hierarchy[4];
        errcode_t       code;

        if (profile == NULL)
                return (EINVAL);

        hierarchy[0] = "logging";
        hierarchy[2] = NULL;
        hierarchy[3] = NULL;

        hierarchy[1] = "default";

        /*
         * Not fatal if this fails, continue on.
         */
        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy,
            "FILE:/var/krb5/kdc.log");
        if (code != 0)
                return (code);

        hierarchy[1] = "kdc";

        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy,
            "FILE:/var/krb5/kdc.log");
        if (code != 0)
                return (code);

        hierarchy[1] = "kdc_rotate";

        hierarchy[2] = "period";

        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, "1d");
        if (code != 0)
                return (code);

        hierarchy[2] = "versions";

        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, "10");

        return (code);
}

errcode_t
__profile_set_libdefaults(profile_t profile, char *realm)
{
        const char      *hierarchy[4];
        errcode_t       code;

        if (profile == NULL || realm == NULL)
                return (EINVAL);

        hierarchy[0] = "libdefaults";
        hierarchy[1] = "default_realm";
        hierarchy[2] = NULL;

        /*
         * Not fatal if this fails, continue on.
         */
        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, realm);

        return (code);
}

errcode_t
__profile_set_kdc(profile_t profile, char *realm, char *kdc,
        boolean_t overwrite)
{
        const char      *hierarchy[4];
        errcode_t       code;

        if (profile == NULL || realm == NULL || kdc == NULL)
                return (EINVAL);

        hierarchy[0] = "realms";
        hierarchy[1] = realm;
        hierarchy[3] = NULL;

        hierarchy[2] = "kdc";

        if (overwrite == TRUE) {
                /*
                 * Not fatal if this fails, continue on.
                 */
                (void) profile_clear_relation(profile, hierarchy);
        }

        code = profile_add_relation(profile, hierarchy, kdc);

        return (code);
}

/*
 * errcode_t __profile_release(profile_t profile)
 *
 * where profile was the pointer passed back by __profile_init
 * Note: used to commit the associated profile to the backing store
 * (e.g. file) and free profile memory
 * Note: that this function returns an error code which profile_release
 * does not.  With the error code, the application can determine if they
 * need to free the resulting profile information in memory
 */
errcode_t
__profile_release(profile_t profile)
{
        prf_file_t      p, next;
        errcode_t       code;

        if (profile == NULL || profile->magic != PROF_MAGIC_PROFILE)
                return (EINVAL);

        for (p = profile->first_file; p; p = next) {
                next = p->next;
                if ((code = profile_close_file(p)) != 0)
                        return (code);
        }
        profile->magic = 0;
        free(profile);

        return (0);
}

/*
 * void __profile_abandon(profile_t profile)
 *
 * where profile was the pointer passed back by __profile_init
 * Note: used to free any profile information in memory.  Typically can
 * be used in conjunction with __profile_release upon error
 */
void
__profile_abandon(profile_t profile)
{
        profile_abandon(profile);
}

/*
 * errcode_t __profile_add_domain_mapping(profile_t profile, char *domain,
 *      char *realm)
 *
 * where profile was the pointer passed back by __profile_init
 * where domain is the domain name of the associated realm name
 * where realm is the corresponding realm name for the domain
 */
errcode_t
__profile_add_domain_mapping(profile_t profile, char *domain, char *realm)
{
        const char      *hierarchy[4];
        errcode_t       code = 0;

        if (profile == NULL || domain == NULL || realm == NULL)
                return (EINVAL);

        hierarchy[0] = "domain_realm";
        hierarchy[1] = domain;
        hierarchy[2] = NULL;

        /*
         * Not fatal if relation can't be cleared, continue on.
         */
        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, realm);

        return (code);
}

/*
 * errcode_t __profile_remove_domain_mapping(profile_t profile, char *realm)
 *
 * where profile was the pointer passed back by __profile_init
 * where domain is the domain name of the associated realm name
 * where realm is the corresponding realm name for the domain
 * Note: for the remove function, all matching domain - realm mappings
 * will be removed for realm
 */
errcode_t
__profile_remove_domain_mapping(profile_t profile, char *realm)
{
        const char      *hierarchy[4];
        errcode_t       code;
        char            **domains = NULL, **domain = NULL;

        if (profile == NULL || realm == NULL)
                return (EINVAL);

        hierarchy[0] = "domain_realm";
        hierarchy[1] = NULL;
        hierarchy[2] = NULL;

        code = __profile_get_domain_realm(profile, realm, &domains);
        if (code == 0 && domains != NULL) {
                for (domain = domains; *domain; domain++) {
                        hierarchy[1] = *domain;
                        code = profile_clear_relation(profile, hierarchy);
                        if (code != 0)
                                goto error;
                }
        }

error:
        if (domains != NULL)
                profile_free_list(domains);

        return (code);
}

/*
 * errcode_t __profile_get_realm_entry(profile_t profile, char *realm,
 *      char *name, char ***ret_value)
 *
 * where profile was the pointer passed back by __profile_init
 * where realm is the target realm for lookup
 * where name is the name in the realm section requested
 * where value is a string array of any matching values assigned to name.
 * The array is terminated with a NULL pointer.
 * Note: if no name has been configured and a profile does exist
 * then value is set to NULL
 */
errcode_t
__profile_get_realm_entry(profile_t profile, char *realm, char *name,
        char ***ret_value)
{
        const char      *hierarchy[4];
        errcode_t       code;
        char            **values = NULL;

        if (profile == NULL || realm == NULL || name == NULL ||
            ret_value == NULL)
                return (EINVAL);

        hierarchy[0] = "realms";
        hierarchy[1] = realm;
        hierarchy[2] = name;
        hierarchy[3] = NULL;

        code = profile_get_values(profile, hierarchy, &values);
        if (code == 0 && values != NULL)
                *ret_value = values;

        if (code == PROF_NO_RELATION)
                code = 0;

        return (code);
}

/*
 * errcode_t __profile_add_realm_entry(profile_t profile, char *realm,
 *      char *name, char **value)
 *
 * where profile was the pointer passed back by __profile_init
 * where realm is the target realm for the name-value pair
 * where name is the name in the realm subsection to add
 * where value is a string array values to assigned to name.  The array is
 * terminated with a NULL pointer.
 * Note: if the realm subsection does no exist then an error is returned
 * Note: if the name already exists the set is overwritten with the values
 * passed
 */
errcode_t
__profile_add_realm_entry(profile_t profile, char *realm, char *name,
        char **values)
{
        const char      *hierarchy[4];
        errcode_t       code;
        char            **tvalue = NULL;

        if (profile == NULL || realm == NULL || name == NULL || values == NULL)
                return (EINVAL);

        hierarchy[0] = "realms";
        hierarchy[1] = realm;
        hierarchy[2] = name;
        hierarchy[3] = NULL;

        /*
         * Not fatal if this fails, continue on.
         */
        (void) profile_clear_relation(profile, hierarchy);

        for (tvalue = values; *tvalue; tvalue++) {

                code = profile_add_relation(profile, hierarchy, *tvalue);
                if (code != 0)
                        return (code);
        }

        return (0);
}

/*
 * errcode_t __profile_get_default_realm(profile_t profile, char **realm)
 *
 * where profile was the pointer passed back by __profile_init
 * where realm is the default_realm configured for the system
 * Note: if no default_realm has been configured and a profile does exist
 * then realm is set to NULL
 */
errcode_t
__profile_get_default_realm(profile_t profile, char **realm)
{
        errcode_t       code;
        char            *value = NULL;

        if (profile == NULL || realm == NULL)
                return (EINVAL);

        code = profile_get_string(profile, "libdefaults", "default_realm", 0, 0,
            &value);
        if (code == 0 && value != NULL)
                *realm = value;

        if (code == PROF_NO_RELATION)
                code = 0;

        return (code);
}

/*
 * errcode_t __profile_get_realms(profile_t profile, char ***realms)
 *
 * where profile was the pointer passed back by __profile_init
 * where realms is a string array of realm names currently configured.
 * The array is terminated with a NULL pointer.
 * Note: if no realms have been configured and a profile does exist then
 * realms is set to NULL
 */
errcode_t
__profile_get_realms(profile_t profile, char ***realms)
{

        if (profile == NULL || realms == NULL)
                return (EINVAL);

        return (__profile_iter_name_value(profile, "realms", NULL, realms));
}

/*
 * errcode_t __profile_add_realm(profile_t profile, char *realm,
 *      char *master, char **kdcs, boolean_t set_change, boolean_t
 *      default_realm)
 *
 * where profile was the pointer passed back by __profile_init
 * where realm is the realm name associated with the configuration
 * where master is the server that is assigned to admin_server
 * where kdcs is a string array of KDCs used to populate the kdc set.
 * The array is terminated with a NULL pointer.
 * where set_change, if set, will use the SET_CHANGE protocol for password
 * modifications.  RPCSEC_GSS is set by default
 * where default_realm, if set, will assign the realm to default_realm
 * Note: the ordering of kdcs is determined by the server's position in the
 * array
 * Note: kdcs must be assigned a value, even if it is the same value as the
 * master.
 */
errcode_t
__profile_add_realm(profile_t profile, char *realm, char *master, char **kdcs,
        boolean_t set_change, boolean_t default_realm)
{
        const char      *hierarchy[4];
        errcode_t       code;
        boolean_t       ow = TRUE;
        char            **tkdcs;

        if (profile == NULL || realm == NULL || master == NULL || kdcs == NULL)
                return (EINVAL);

        /*
         * Sets the default realm to realm if default_realm flag is set.
         */
        if (default_realm == TRUE) {
                if (code = __profile_set_libdefaults(profile, realm))
                        return (code);
        }

        hierarchy[0] = "realms";
        hierarchy[1] = realm;
        hierarchy[3] = NULL;

        hierarchy[2] = "admin_server";

        /*
         * Not fatal if this fails, therefore return code is not checked.
         */
        (void) profile_clear_relation(profile, hierarchy);

        if (code = profile_add_relation(profile, hierarchy, master))
                return (code);

        /*
         * If not set then defaults to undefined, which defaults to RPCSEC_GSS.
         */
        if (set_change == TRUE) {
                hierarchy[2] = "kpasswd_protocol";

                (void) profile_clear_relation(profile, hierarchy);

                code = profile_add_relation(profile, hierarchy, "SET_CHANGE");
                if (code != 0)
                        return (code);
        }

        for (tkdcs = kdcs; *tkdcs; tkdcs++) {
                if (code = __profile_set_kdc(profile, realm, *tkdcs, ow))
                        return (code);
                ow = FALSE;
        }

        code = __profile_set_logging(profile);
        if (code != 0)
                return (code);

        code = __profile_set_appdefaults(profile);

        return (code);
}

/*
 * errcode_t __profile_remove_xrealm_mapping(profile_t profile, char *realm)
 *
 * where profile was the pointer passed back by __profile_init
 * where source is the source realm for the capath
 * where target is the target realm for the capath
 * where inter is the intermediate realm between the source and target
 * realms.  If the source and target share x-realm keys then this set to "."
 * Note: for the remove function, all associated source, target, and
 * intermediate entries will be removed matching the realm name
 */
errcode_t
__profile_remove_xrealm_mapping(profile_t profile, char *realm)
{
        const char      *hierarchy[4];
        errcode_t       code, code2, code3;
        void            *state = NULL, *state2 = NULL;
        char            *source = NULL, *dummy_val = NULL, *target = NULL;
        char            *inter = NULL;

        if (profile == NULL || realm == NULL)
                return (EINVAL);

        hierarchy[0] = "capaths";
        hierarchy[1] = realm;
        hierarchy[2] = NULL;
        hierarchy[3] = NULL;

        /*
         * Not fatal if this fails, continue on.
         */
        code = profile_rename_section(profile, hierarchy, NULL);

        hierarchy[1] = NULL;
        code = profile_iterator_create(profile, hierarchy,
            PROFILE_ITER_LIST_SECTION, &state);
        while (code == 0) {
                code = profile_iterator(&state, &source, &dummy_val);
                if (code == 0 && source != NULL) {
                        hierarchy[1] = source;
                        code2 = profile_iterator_create(profile, hierarchy,
                            PROFILE_ITER_LIST_SECTION, &state2);
                        while (code2 == 0) {
                                code2 = profile_iterator(&state2, &target,
                                    &inter);
                                if (code2 == 0 && target != NULL &&
                                    inter != NULL) {
                                        if (strcmp(realm, target) == 0 ||
                                            strcmp(realm, inter) == 0) {
                                                hierarchy[2] = target;
                                                code3 =
                                                    profile_clear_relation(
                                                    profile, hierarchy);
                                                if (code3 != 0) {
                                                        code = code3;
                                                        goto error;
                                                }
                                        }
                                }
                                if (target != NULL) {
                                        profile_release_string(target);
                                        target = NULL;
                                }
                                if (inter != NULL) {
                                        profile_release_string(inter);
                                        inter = NULL;
                                }
                        }
                }
                if (source != NULL) {
                        profile_release_string(source);
                        source = NULL;
                }
                if (dummy_val != NULL) {
                        profile_release_string(dummy_val);
                        dummy_val = NULL;
                }
        }
        code = 0;

error:
        if (state != NULL)
                profile_iterator_free(&state);
        if (state2 != NULL)
                profile_iterator_free(&state2);
        if (target != NULL)
                profile_release_string(target);
        if (inter != NULL)
                profile_release_string(inter);
        if (source != NULL)
                profile_release_string(source);
        if (dummy_val != NULL)
                profile_release_string(dummy_val);

        return (code);
}

/*
 * errcode_t __profile_remove_realm(profile_t profile, char *realm)
 *
 * where profile was the pointer passed back by __profile_init
 * where realm is the target realm for removal
 * Note: the function removes the matching realm in the realms section,
 * the default_realm, relevant domain_realm mappings with the realm name,
 * and matching capaths source realm subsection.
 */
errcode_t
__profile_remove_realm(profile_t profile, char *realm)
{
        const char      *hierarchy[4];
        errcode_t       code;
        char            *drealm = NULL;

        if (profile == NULL || realm == NULL)
                return (EINVAL);

        /*
         * Remove the default realm.
         */
        hierarchy[0] = "libdefaults";
        hierarchy[1] = "default_realm";
        hierarchy[2] = NULL;

        code = __profile_get_default_realm(profile, &drealm);
        if (code != 0)
                return (code);
        else if (drealm != NULL) {
                if (strcmp(drealm, realm) == 0) {
                        code = profile_clear_relation(profile, hierarchy);
                        if (code != 0) {
                                free(drealm);
                                return (code);
                        }
                }
                free(drealm);
        }

        hierarchy[0] = "realms";
        hierarchy[1] = realm;
        hierarchy[2] = NULL;

        code = profile_rename_section(profile, hierarchy, NULL);
        if (code != 0)
                return (code);

        code = __profile_remove_domain_mapping(profile, realm);
        if (code != 0)
                return (code);

        code = __profile_remove_xrealm_mapping(profile, realm);
        if (code != 0)
                return (code);

        /*
         * Not fatal even if realm wasn't available to remove.
         */
        return (0);
}

/*
 * errcode_t __profile_add_xrealm_mapping(profile_t profile, char *source,
 *      char *target, char *inter)
 *
 * where profile was the pointer passed back by __profile_init
 * where source is the source realm for the capath
 * where target is the target realm for the capath
 * where inter is the intermediate realm between the source and target
 * realms.  If the source and target share x-realm keys then this set to "."
 * Note: if the section does not exist one will be created
 */
errcode_t
__profile_add_xrealm_mapping(profile_t profile, char *source, char *target,
        char *inter)
{
        const char      *hierarchy[4];
        errcode_t       code;

        if (profile == NULL || source == NULL || target == NULL ||
            inter == NULL)
                return (EINVAL);

        hierarchy[0] = "capaths";
        hierarchy[1] = source;
        hierarchy[2] = target;
        hierarchy[3] = NULL;

        /*
         * Not fatal if this fails, continue on.
         */
        (void) profile_clear_relation(profile, hierarchy);

        code = profile_add_relation(profile, hierarchy, inter);

        return (code);
}

/*
 * errcode_t __profile_validate(profile_t profile, int *val_err, char **val)
 *
 * where profile was the pointer passed back by __profile_init
 * where val_err is a function specific error code of the following values:
 *      0 No errors detected in profile
 *      1 default realm is in lower-case (val returns realm)
 *      2 realm in realms section is in lower-case (val returns realm)
 *      3 default realm is not found in realms section
 *              (val returns realm not found)
 *      4 default realm does not exist
 *      5 no realm found in realms section
 *      6 no domain realm mapping entry found corresponding to a realm
 *              in the realms section (val returns realm name)
 *      7 kdc relation-value does not exist in realm
 *              (val returns realm name)
 *      8 admin_server relation-value does not exist in realm
 *              (val returns realm name)
 * where val is the associated errant value, associated with val_err.  This
 * value is returned as is from the profile
 * Note: function infers the following:
 *      1. REALM should be in upper-case
 *      2. all required entries are present
 *      3. all relations are defined between default realm, realm, and
 *              domain - realm mappings
 *
 * Note: The return value of this function is based on the error code returned
 * by the framework/mechanism.  The function could return zero with the
 * validation error code set to non-zero if the profile is invalid in any way.
 *
 * Caution: This function could return false positives on valid
 * configurations and should only be used by the CIFS team for
 * specific purposes.
 */
errcode_t
__profile_validate(profile_t profile, int *val_err, char **val)
{
        errcode_t       code;
        int             c;
        boolean_t       found = FALSE;
        char            *default_realm = NULL, **realms = NULL, *tr = NULL;
        char            **trealms = NULL, **domains = NULL, **ret_vals = NULL;

        if (profile == NULL || val_err == NULL || val == NULL)
                return (EINVAL);

        *val_err = 0;
        *val = NULL;

        code = __profile_get_default_realm(profile, &default_realm);
        if (code == 0 && default_realm != NULL) {
                tr = default_realm;

                while ((c = *tr++) != 0) {
                        if (islower(c)) {
                                *val_err = 1;
                                *val = strdup(default_realm);
                                if (*val == NULL)
                                        code = ENOMEM;
                                goto cleanup;
                        }
                }
        } else if (code == 0 && default_realm == NULL) {
                *val_err = 4;
                goto cleanup;
        } else
                goto cleanup;

        code = __profile_get_realms(profile, &realms);
        if (code == 0 && realms != NULL) {
                for (trealms = realms; *trealms; trealms++) {

                        tr = *trealms;
                        while ((c = *tr++) != 0) {
                                if (islower(c)) {
                                        *val_err = 2;
                                        *val = strdup(*trealms);
                                        if (*val == NULL)
                                                code = ENOMEM;
                                        goto cleanup;
                                }
                        }

                        if (strcmp(default_realm, *trealms) == 0)
                                found = TRUE;

                        code = __profile_get_domain_realm(profile, *trealms,
                            &domains);
                        if (code == 0 && domains != NULL) {
                                profile_free_list(domains);
                                domains = NULL;
                        } else if (code == 0 && domains == NULL) {
                                *val_err = 6;
                                *val = strdup(*trealms);
                                if (*val == NULL)
                                        code = ENOMEM;
                                goto cleanup;
                        } else
                                goto cleanup;

                        code = __profile_get_realm_entry(profile, *trealms,
                            "kdc", &ret_vals);
                        if (code == 0 && ret_vals != NULL) {
                                profile_free_list(ret_vals);
                                ret_vals = NULL;
                        } else if (code == 0 && ret_vals == NULL) {
                                *val_err = 7;
                                *val = strdup(*trealms);
                                if (*val == NULL)
                                        code = ENOMEM;
                                goto cleanup;
                        } else
                                goto cleanup;

                        code = __profile_get_realm_entry(profile, *trealms,
                            "admin_server", &ret_vals);
                        if (code == 0 && ret_vals != NULL) {
                                profile_free_list(ret_vals);
                                ret_vals = NULL;
                        } else if (code == 0 && ret_vals == NULL) {
                                *val_err = 8;
                                *val = strdup(*trealms);
                                if (*val == NULL)
                                        code = ENOMEM;
                                goto cleanup;
                        } else
                                goto cleanup;
                }

                if (found == FALSE) {
                        *val_err = 3;
                        *val = strdup(default_realm);
                        if (*val == NULL)
                                code = ENOMEM;
                        goto cleanup;
                }
        } else if (code == 0 && realms == NULL)
                *val_err = 5;

cleanup:

        if (realms != NULL)
                profile_free_list(realms);
        if (ret_vals != NULL)
                profile_free_list(ret_vals);
        if (default_realm != NULL)
                profile_release_string(default_realm);
        if (domains != NULL)
                profile_free_list(domains);

        return (code);
}

/*
 * errcode_t __profile_init(char *filename, profile_t *profile)
 *
 * where filename is the specified profile location.  If filename is NULL
 * then function uses the system default name, /etc/krb5/krb5.conf
 * where profile is pointer passed to caller upon success
 * Note: if the file does not exist then one will be created
 * Note: if the file does exist then any existing profile information will
 * be in profile
 * Note: profile_release() should be used by the caller to free profile
 */
errcode_t
__profile_init(char *filename, profile_t *profile)
{
        profile_filespec_t      *filenames = NULL;
        krb5_error_code         ret = 0;
        errcode_t               code = 0;
        int                     err = 0, fd;
        mode_t                  mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;

        if (profile == NULL)
                return (EINVAL);

        if (filename != NULL) {
                filenames = malloc(2 * sizeof (char *));
                if (filenames == NULL)
                        return (ENOMEM);
                filenames[0] = strdup(filename);
                if (filenames[0] == NULL) {
                        free(filenames);
                        return (ENOMEM);
                }
                filenames[1] = NULL;
        } else {
                ret = krb5_get_default_config_files(&filenames);
                if (ret != 0)
                        return (ret);
        }

        /*
         * If file does not exist then create said file.
         */
        fd = open(*filenames, O_RDWR|O_CREAT|O_NOFOLLOW|O_NOLINKS, mode);
        if (fd < 0) {
                err = errno;
                krb5_free_config_files(filenames);
                return (err);
        } else
                close(fd);

        /*
         * Specify non-null for specific file (to load any existing profile)
         */
        code = profile_init((const_profile_filespec_t *)filenames, profile);

        krb5_free_config_files(filenames);

        return (code);
}