lib/libgss/g_utils.c

/*
 * 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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <ctype.h>
#include <errno.h>
#include <gssapi/gssapi.h>
#include <gssapi/gssapi_ext.h>
#include <synch.h>

#define Q_DEFAULT       "default"
#define BUFLEN          256

static int qop_num_pair_cnt;
static const char    QOP_NUM_FILE[] = "/etc/gss/qop";
static qop_num  qop_num_pairs[MAX_QOP_NUM_PAIRS+1];
static mutex_t qopfile_lock = DEFAULTMUTEX;

static OM_uint32 __gss_read_qop_file(void);

/*
 * This routine fetches qop and num from "/etc/gss/qop".
 * There is a memory leak associated with rereading this file,
 * because we can't free the qop_num_pairs array when we reread
 * the file (some callers may have been given these pointers).
 * In general, this memory leak should be a small one, because
 * we don't expect the qop file to be changed and reread often.
 */
static OM_uint32
__gss_read_qop_file(void)
{
    char    buf[BUFLEN];    /* one line from the file */
    char    *name, *next;
    char    *qopname, *num_str;
    char    *line;
    FILE    *fp;
    static int last = 0;
    struct stat stbuf;
    OM_uint32 major = GSS_S_COMPLETE;

    (void) mutex_lock(&qopfile_lock);
    if (stat(QOP_NUM_FILE, &stbuf) != 0 || stbuf.st_mtime < last) {
        if (!qop_num_pairs[0].qop) {
            major = GSS_S_FAILURE;
        }
        goto done;
    }
    last = stbuf.st_mtime;

    fp = fopen(QOP_NUM_FILE, "rF");
    if (fp == (FILE *)0) {
        major = GSS_S_FAILURE;
        goto done;
    }

    /*
     * For each line in the file parse it appropriately.
     * File format : qopname    num(int)
     * Note that we silently ignore corrupt entries.
     */
    qop_num_pair_cnt = 0;
    while (!feof(fp)) {
        line = fgets(buf, BUFLEN, fp);
        if (line == NULL)
            break;

        /* Skip comments and blank lines */
        if ((*line == '#') || (*line == '\n'))
            continue;

        /* Skip trailing comments */
        next = strchr(line, '#');
        if (next)
            *next = '\0';

        name = &(buf[0]);
        while (isspace(*name))
            name++;
        if (*name == '\0')  /* blank line */
            continue;

        qopname = name; /* will contain qop name */
        while (!isspace(*qopname))
            qopname++;
        if (*qopname == '\0') {
            continue;
        }
        next = qopname+1;
        *qopname = '\0';    /* null terminate qopname */
        qop_num_pairs[qop_num_pair_cnt].qop = strdup(name);
        if (qop_num_pairs[qop_num_pair_cnt].qop == NULL)
            continue;

        name = next;
        while (isspace(*name))
            name++;
        if (*name == '\0') {    /* end of line, no num */
            free(qop_num_pairs[qop_num_pair_cnt].qop);
            continue;
        }
        num_str = name; /* will contain num (n) */
        while (!isspace(*num_str))
            num_str++;
        next = num_str+1;
        *num_str++ = '\0';  /* null terminate num_str */

        qop_num_pairs[qop_num_pair_cnt].num = (OM_uint32)atoi(name);
        name = next;
        while (isspace(*name))
            name++;
        if (*name == '\0') {    /* end of line, no mechanism */
            free(qop_num_pairs[qop_num_pair_cnt].qop);
            continue;
        }
        num_str = name; /* will contain mech */
        while (!isspace(*num_str))
            num_str++;
        *num_str = '\0';

        qop_num_pairs[qop_num_pair_cnt].mech = strdup(name);
        if (qop_num_pairs[qop_num_pair_cnt].mech == NULL) {
            free(qop_num_pairs[qop_num_pair_cnt].qop);
            continue;
        }

        if (qop_num_pair_cnt++ >= MAX_QOP_NUM_PAIRS)
            break;
    }
    (void) fclose(fp);
done:
    (void) mutex_unlock(&qopfile_lock);
    return (major);
}

OM_uint32
__gss_qop_to_num(
    char        *qop,
    char        *mech,
    OM_uint32   *num
)
{
    int i;
    OM_uint32 major = GSS_S_FAILURE;

    if (!num)
        return (GSS_S_CALL_INACCESSIBLE_WRITE);

    if (qop == NULL || strlen(qop) == 0 ||
            strcasecmp(qop, Q_DEFAULT) == 0) {
        *num = GSS_C_QOP_DEFAULT;
        return (GSS_S_COMPLETE);
    }

    if ((major = __gss_read_qop_file()) != GSS_S_COMPLETE)
        return (major);

    for (i = 0; i < qop_num_pair_cnt; i++) {
        if ((strcasecmp(mech, qop_num_pairs[i].mech) == 0) &&
            (strcasecmp(qop, qop_num_pairs[i].qop) == 0)) {
            *num = qop_num_pairs[i].num;
            return (GSS_S_COMPLETE);
        }
    }

    return (GSS_S_FAILURE);
}

OM_uint32
__gss_num_to_qop(
    char        *mech,
    OM_uint32   num,
    char        **qop
)
{
    int i;
    OM_uint32 major;

    if (!qop)
        return (GSS_S_CALL_INACCESSIBLE_WRITE);
    *qop = NULL;

    if (num == GSS_C_QOP_DEFAULT) {
        *qop = Q_DEFAULT;
        return (GSS_S_COMPLETE);
    }

    if (mech == NULL)
        return (GSS_S_CALL_INACCESSIBLE_READ);

    if ((major = __gss_read_qop_file()) != GSS_S_COMPLETE)
        return (major);

    for (i = 0; i < qop_num_pair_cnt; i++) {
        if ((strcasecmp(mech, qop_num_pairs[i].mech) == 0) &&
            (num == qop_num_pairs[i].num)) {
            *qop = qop_num_pairs[i].qop;
            return (GSS_S_COMPLETE);
        }
    }
    return (GSS_S_FAILURE);
}

/*
 * For a given mechanism pass back qop information about it in a buffer
 * of size MAX_QOPS_PER_MECH+1.
 */
OM_uint32
__gss_get_mech_info(
    char        *mech,
    char        **qops
)
{
    int i, cnt = 0;
    OM_uint32 major = GSS_S_COMPLETE;

    if (!qops)
        return (GSS_S_CALL_INACCESSIBLE_WRITE);
    *qops = NULL;

    if (!mech)
        return (GSS_S_CALL_INACCESSIBLE_READ);

    if ((major = __gss_read_qop_file()) != GSS_S_COMPLETE)
        return (major);

    for (i = 0; i < qop_num_pair_cnt; i++) {
        if (strcmp(mech, qop_num_pairs[i].mech) == 0) {
            if (cnt >= MAX_QOPS_PER_MECH) {
            return (GSS_S_FAILURE);
            }
            qops[cnt++] = qop_num_pairs[i].qop;
        }
    }
    qops[cnt] = NULL;
    return (GSS_S_COMPLETE);
}

/*
 * Copy the qop values and names for the mechanism back in a qop_num
 * buffer of size MAX_QOPS_PER_MECH provided by the caller.
 */
OM_uint32
__gss_mech_qops(
    char *mech,
    qop_num *mechqops,
    int *numqop
)
{
    int i;
    OM_uint32 major;
    int cnt = 0;

    if (!mechqops || !numqop)
        return (GSS_S_CALL_INACCESSIBLE_WRITE);
    *numqop = 0;

    if (!mech)
        return (GSS_S_CALL_INACCESSIBLE_READ);

    if ((major = __gss_read_qop_file()) != GSS_S_COMPLETE)
        return (major);

    for (i = 0; i < qop_num_pair_cnt; i++) {
        if (strcasecmp(mech, qop_num_pairs[i].mech) == 0) {
        if (cnt >= MAX_QOPS_PER_MECH) {
            return (GSS_S_FAILURE);
        }
        mechqops[cnt++] = qop_num_pairs[i];
        }
    }
    *numqop = cnt;
    return (GSS_S_COMPLETE);
}