libkmf/common/mapping.c

	mapping.c revision 269e59f9a28bf47e0f463e64fc5af4a408b73b21
/*
 * 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) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * This file implements the KMF certificate to name mapping framework.
 */
#include <stdlib.h>
#include <string.h>
#include <dlfcn.h>
#include <libgen.h>
#include <kmftypes.h>
#include <kmfapiP.h>

/* Mappers go in the same dir as plugins. */
#define DEFAULT_MAPPER_DIR KMF_PLUGIN_PATH

static void
cleanup_mapper(KMF_HANDLE_T handle)
{
    KMF_MAPPER_RECORD *mapper = &handle->policy->mapper;
    void (*finalize)(KMF_HANDLE_T);

    if (mapper->curpathname != NULL) {
        free(mapper->curpathname);
        mapper->curpathname = NULL;
    }
    if (mapper->curoptions != NULL) {
        free(mapper->curoptions);
        mapper->curoptions = NULL;
    }
    if (mapper->dldesc != NULL) {
        finalize = (void(*)())dlsym(mapper->dldesc,
            MAPPER_FINISH_FUNCTION);
        /* Optional, not an error if it does not exist. */
        if (finalize != NULL)
            finalize(handle);

        (void) dlclose(mapper->dldesc);
        mapper->dldesc = NULL;
    }
}

/* The caller is expected to free the returned string. */
char *
get_mapper_pathname(char *name, char *dir)
{
    char *pathname = NULL;
    int len;

    if (name == NULL)
        return (NULL);

    if (dir == NULL)
        dir = DEFAULT_MAPPER_DIR;

    /*
     * MAPPER_NAME_TEMPLATE has 2 extra characters (%s) which make up for
     * the "/" and the terminating NULL when computing the total length.
     */
    len = strlen(name) + strlen(MAPPER_NAME_TEMPLATE) + strlen(dir);

    pathname = malloc(len);
    if (pathname == NULL)
        return (NULL);
    (void) memset(pathname, 0, len);
    /* Avoid double forward slash if the dir's last character is "/". */
    (void) snprintf(pathname, len, "%s%s" MAPPER_NAME_TEMPLATE,
        dir, dir[strlen(dir) - 1] == '/' ? "" : "/", name);

    return (pathname);
}

static KMF_RETURN
open_mapper_library(KMF_MAPPER_RECORD *map)
{
    KMF_RETURN ret = KMF_OK;

    map->dldesc = dlopen(map->curpathname, RTLD_LAZY | RTLD_PARENT);
    if (map->dldesc == NULL)
        return (KMF_ERR_MAPPER_OPEN);

    return (ret);
}

/*
 * The mapping framework uses either attributes or the policy file. Those two
 * sources are never mixed. We always need a mapper name or a mapper pathname
 * but these two are mutually exclusive. Directory can be set only if name is
 * set.
 */
KMF_RETURN
kmf_cert_to_name_mapping_initialize(KMF_HANDLE_T handle, int numattr,
    KMF_ATTRIBUTE *attrlist)
{
    KMF_RETURN ret = KMF_OK;
    KMF_RETURN (*initialize)(KMF_HANDLE_T, char *);
    KMF_MAPPER_RECORD *map = NULL;
    char *dir = NULL;
    char *name = NULL;
    char *opts = NULL;
    char *path = NULL;
    char *tmppath = NULL;
    char *old_curpathname = NULL;
    char *old_curoptions = NULL;

    if (handle == NULL)
        return (KMF_ERR_BAD_PARAMETER);

    map = &handle->policy->mapper;
    old_curpathname = map->curpathname;
    old_curoptions = map->curoptions;

    name = kmf_get_attr_ptr(KMF_MAPPER_NAME_ATTR, attrlist, numattr);
    dir = kmf_get_attr_ptr(KMF_DIRPATH_ATTR, attrlist, numattr);
    path = kmf_get_attr_ptr(KMF_MAPPER_PATH_ATTR, attrlist, numattr);
    opts = kmf_get_attr_ptr(KMF_MAPPER_OPTIONS_ATTR, attrlist, numattr);

    if (path != NULL) {
        /* Mutually exclusive. */
        if (name != NULL || dir != NULL)
            return (KMF_ERR_BAD_PARAMETER);
        tmppath = strdup(path);
        if (tmppath == NULL)
            return (KMF_ERR_MEMORY);
    /* If we only have a name and possibly a dir, we can find the path. */
    } else if (name != NULL) {
        tmppath = get_mapper_pathname(name, dir);
        /*
         * If we were given name but the returned path is still NULL,
         * return an error.
         */
        if (tmppath == NULL)
            return (KMF_ERR_MEMORY);
    /* Can not exist standalone. */
    } else if (dir != NULL || opts != NULL) {
            return (KMF_ERR_BAD_PARAMETER);
    /* No attributes define the mapper so let's use the policy database. */
    } else if (map->pathname != NULL) {
        tmppath = strdup(map->pathname);
        if (tmppath == NULL)
            return (KMF_ERR_MEMORY);
        opts = map->options;
    } else if (map->mapname != NULL) {
        tmppath = get_mapper_pathname(map->mapname, map->dir);
        /*
         * If we were given name but the returned path is still NULL,
         * return an error.
         */
        if (tmppath == NULL)
            return (KMF_ERR_MEMORY);
        opts = map->options;
    } else {
        /*
         * Either a name or a full pathname must be provided whether
         * from attributes or the policy database.
         */
        return (KMF_ERR_BAD_PARAMETER);
    }

    /*
     * Dlopen the mapper specified by the policy. If anything goes wrong
     * just return an error. We do not have to worry about resetting
     * curpathname and curoptions to the previous values since there was no
     * mapper initialized beforehand.
     *
     * No mapper was open so stored curoptions and curpathname are
     * already NULL and need not to be freed.
     */
    if (map->dldesc == NULL) {
        map->curpathname = tmppath;
        if (opts != NULL) {
            map->curoptions = strdup(opts);
            if (map->curoptions == NULL) {
                free(map->curpathname);
                map->curpathname = NULL;
                return (KMF_ERR_MEMORY);
            }
        } else
            map->curoptions = NULL;

        if ((ret = open_mapper_library(map)) != KMF_OK) {
            free(map->curpathname);
            map->curpathname = NULL;
            if (map->curoptions != NULL) {
                free(map->curoptions);
                map->curoptions = NULL;
            }
            return (ret);
        }

        goto end;
    }

    /*
     * We already have an open mapper, let's see if this is a new mapper
     * library.
     */
    if (map->curpathname != NULL &&
        /* No change in mapper pathname. */
        strcmp(map->curpathname, tmppath) == 0) {
        /* New options are empty while we had some before. */
        if (map->curoptions != NULL && opts == NULL) {
            map->curoptions = NULL;
        /* We have some options now while we had none before. */
        } else if (map->curoptions == NULL && opts != NULL) {
            if ((map->curoptions = strdup(opts)) == NULL)
                goto err_mem;
        /* We got different options. */
        } else if (strcmp(map->curoptions, opts) != 0) {
            if ((map->curoptions = strdup(opts)) == NULL)
                goto err_mem;
        } else {
            /*
             * Same options, no free() of current options is
             * required.
             */
            old_curoptions = NULL;
        }

        /* Free old options if applicable. */
        if (old_curoptions != NULL)
            free(old_curoptions);
    } else {
        /*
         * This is a new mapper path, clean up the old data and open the
         * new mapper.
         */
        cleanup_mapper(handle);
        /* These two are no longer valid. */
        old_curoptions = NULL;
        old_curpathname = NULL;
        map->curpathname = tmppath;
        if (opts != NULL) {
            map->curoptions = strdup(opts);
            if (map->curoptions == NULL)
                goto err_mem;
        }
        if ((ret = open_mapper_library(map)) != KMF_OK) {
            /*
             * This will cleanup curoptions and curpathname, and
             * ignores the dldesc since it is NULL. Do not free
             * tmppath, it will be freed through map->curpathname.
             */
            cleanup_mapper(handle);
            return (ret);
        }
    }

end:
    initialize = (KMF_RETURN(*)())dlsym(map->dldesc,
        MAPPER_INIT_FUNCTION);
    /* Optional, not an error if it does not exist. */
    ret = KMF_OK;
    if (initialize != NULL)
        ret = initialize(handle, map->curoptions);

    if (ret != KMF_OK)
        cleanup_mapper(handle);

    return (ret);

err_mem:
    /*
     * Try to put the old curpathname and curoptions back there. In theory,
     * the application might be able to continue to use the old mapping
     * unless we already called cleanup_mapper(). However, it's neither
     * recommended nor officially supported. The app should initialize the
     * old mapping again.
     */
    if (tmppath != NULL)
        free(tmppath);
    map->curoptions = old_curoptions;
    map->curpathname = old_curpathname;
    return (KMF_ERR_MEMORY);
}

KMF_RETURN
kmf_cert_to_name_mapping_finalize(KMF_HANDLE_T handle)
{
    if (handle == NULL)
        return (KMF_ERR_BAD_PARAMETER);

    cleanup_mapper(handle);

    return (KMF_OK);
}

KMF_RETURN
kmf_map_cert_to_name(KMF_HANDLE_T handle, KMF_DATA *cert, KMF_DATA *name)
{
    KMF_MAPPER_RECORD *map = NULL;
    KMF_RETURN (*cert2name)(KMF_HANDLE *, KMF_DATA *, KMF_DATA *);

    if (handle == NULL)
        return (KMF_ERR_BAD_PARAMETER);

    map = &handle->policy->mapper;
    if (map->dldesc == NULL)
        return (KMF_ERR_MAPPER_NOT_FOUND);

    cert2name = (KMF_RETURN(*)())dlsym(map->dldesc,
        MAP_CERT_TO_NAME_FUNCTION);
    if (cert2name == NULL)
        return (KMF_ERR_FUNCTION_NOT_FOUND);

    return (cert2name(handle, cert, name));
}

/*
 * If mapped_name is non-NULL the caller is later expected to free its Data
 * after use.
 */
KMF_RETURN
kmf_match_cert_to_name(KMF_HANDLE_T handle, KMF_DATA *cert,
    KMF_DATA *name_to_match, KMF_DATA *mapped_name)
{
    KMF_MAPPER_RECORD *map = NULL;
    KMF_RETURN (*cert2name)(KMF_HANDLE *, KMF_DATA *, KMF_DATA *,
        KMF_DATA *);

    if (handle == NULL)
        return (KMF_ERR_BAD_PARAMETER);

    map = &handle->policy->mapper;

    if (map->curpathname == NULL || map->dldesc == NULL)
        return (KMF_ERR_MAPPER_NOT_FOUND);

    cert2name = (KMF_RETURN(*)())dlsym(map->dldesc,
        MATCH_CERT_TO_NAME_FUNCTION);
    if (cert2name == NULL)
        return (KMF_ERR_FUNCTION_NOT_FOUND);

    return (cert2name(handle, cert, name_to_match, mapped_name));
}

/*
 * The caller is responsible for freeing the error string (ie., *errstr) when
 * done with it.
 */
KMF_RETURN
kmf_get_mapper_error_str(KMF_HANDLE_T handle, char **errstr)
{
    KMF_HANDLE *h = NULL;
    KMF_MAPPER_RECORD *map = NULL;
    KMF_RETURN (*err2string)(KMF_HANDLE *, char **);

    if (handle == NULL || errstr == NULL)
        return (KMF_ERR_BAD_PARAMETER);

    h = (KMF_HANDLE *)handle;
    map = &(h->policy->mapper);

    if (map->curpathname == NULL || map->dldesc == NULL)
        return (KMF_ERR_MAPPER_NOT_FOUND);

    err2string = (KMF_RETURN(*)())dlsym(map->dldesc,
        MAPPER_ERROR_STRING_FUNCTION);
    if (err2string == NULL)
        return (KMF_ERR_FUNCTION_NOT_FOUND);

    return (err2string(h, errstr));
}

void
kmf_set_mapper_lasterror(KMF_HANDLE_T handle, uint32_t err)
{
    handle->mapstate->lastmappererr = err;
}

uint32_t
kmf_get_mapper_lasterror(KMF_HANDLE_T handle)
{
    return (handle->mapstate->lastmappererr);
}

void
kmf_set_mapper_options(KMF_HANDLE_T handle, void *opts)
{
    handle->mapstate->options = opts;
}

void *
kmf_get_mapper_options(KMF_HANDLE_T handle)
{
    return (handle->mapstate->options);
}