freebsd-dev/crypto/kerberosIV/lib/kafs/common.c
2000-01-09 08:31:47 +00:00

397 lines
10 KiB
C

/*
* Copyright (c) 1997, 1998, 1999 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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 the Institute 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 THE INSTITUTE 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 THE INSTITUTE 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 "kafs_locl.h"
RCSID("$Id: common.c,v 1.19 1999/12/02 16:58:40 joda Exp $");
#define AUTH_SUPERUSER "afs"
/*
* Here only ASCII characters are relevant.
*/
#define IsAsciiLower(c) ('a' <= (c) && (c) <= 'z')
#define ToAsciiUpper(c) ((c) - 'a' + 'A')
static void
foldup(char *a, const char *b)
{
for (; *b; a++, b++)
if (IsAsciiLower(*b))
*a = ToAsciiUpper(*b);
else
*a = *b;
*a = '\0';
}
int
kafs_settoken(const char *cell, uid_t uid, CREDENTIALS *c)
{
struct ViceIoctl parms;
struct ClearToken ct;
int32_t sizeof_x;
char buf[2048], *t;
int ret;
/*
* Build a struct ClearToken
*/
ct.AuthHandle = c->kvno;
memcpy (ct.HandShakeKey, c->session, sizeof(c->session));
ct.ViceId = uid;
ct.BeginTimestamp = c->issue_date;
ct.EndTimestamp = krb_life_to_time(c->issue_date, c->lifetime);
if(ct.EndTimestamp < time(NULL))
return 0; /* don't store tokens that has expired (and possibly
overwriting valid tokens)*/
#define ODD(x) ((x) & 1)
/* According to Transarc conventions ViceId is valid iff
* (EndTimestamp - BeginTimestamp) is odd. By decrementing EndTime
* the transformations:
*
* (issue_date, life) -> (StartTime, EndTime) -> (issue_date, life)
* preserves the original values.
*/
if (uid != 0) /* valid ViceId */
{
if (!ODD(ct.EndTimestamp - ct.BeginTimestamp))
ct.EndTimestamp--;
}
else /* not valid ViceId */
{
if (ODD(ct.EndTimestamp - ct.BeginTimestamp))
ct.EndTimestamp--;
}
t = buf;
/*
* length of secret token followed by secret token
*/
sizeof_x = c->ticket_st.length;
memcpy(t, &sizeof_x, sizeof(sizeof_x));
t += sizeof(sizeof_x);
memcpy(t, c->ticket_st.dat, sizeof_x);
t += sizeof_x;
/*
* length of clear token followed by clear token
*/
sizeof_x = sizeof(ct);
memcpy(t, &sizeof_x, sizeof(sizeof_x));
t += sizeof(sizeof_x);
memcpy(t, &ct, sizeof_x);
t += sizeof_x;
/*
* do *not* mark as primary cell
*/
sizeof_x = 0;
memcpy(t, &sizeof_x, sizeof(sizeof_x));
t += sizeof(sizeof_x);
/*
* follow with cell name
*/
sizeof_x = strlen(cell) + 1;
memcpy(t, cell, sizeof_x);
t += sizeof_x;
/*
* Build argument block
*/
parms.in = buf;
parms.in_size = t - buf;
parms.out = 0;
parms.out_size = 0;
ret = k_pioctl(0, VIOCSETTOK, &parms, 0);
return ret;
}
/* Try to get a db-server for an AFS cell from a AFSDB record */
static int
dns_find_cell(const char *cell, char *dbserver, size_t len)
{
struct dns_reply *r;
int ok = -1;
r = dns_lookup(cell, "afsdb");
if(r){
struct resource_record *rr = r->head;
while(rr){
if(rr->type == T_AFSDB && rr->u.afsdb->preference == 1){
strlcpy(dbserver,
rr->u.afsdb->domain,
len);
ok = 0;
break;
}
rr = rr->next;
}
dns_free_data(r);
}
return ok;
}
/*
* Try to find the cells we should try to klog to in "file".
*/
static void
find_cells(char *file, char ***cells, int *index)
{
FILE *f;
char cell[64];
int i;
int ind = *index;
f = fopen(file, "r");
if (f == NULL)
return;
while (fgets(cell, sizeof(cell), f)) {
char *t;
t = cell + strlen(cell);
for (; t >= cell; t--)
if (*t == '\n' || *t == '\t' || *t == ' ')
*t = 0;
if (cell[0] == '\0' || cell[0] == '#')
continue;
for(i = 0; i < ind; i++)
if(strcmp((*cells)[i], cell) == 0)
break;
if(i == ind){
char **tmp;
tmp = realloc(*cells, (ind + 1) * sizeof(**cells));
if (tmp == NULL)
break;
*cells = tmp;
(*cells)[ind] = strdup(cell);
if ((*cells)[ind] == NULL)
break;
++ind;
}
}
fclose(f);
*index = ind;
}
/*
* Get tokens for all cells[]
*/
static int
afslog_cells(kafs_data *data, char **cells, int max, uid_t uid,
const char *homedir)
{
int ret = 0;
int i;
for (i = 0; i < max; i++) {
int er = (*data->afslog_uid)(data, cells[i], 0, uid, homedir);
if (er)
ret = er;
}
return ret;
}
int
_kafs_afslog_all_local_cells(kafs_data *data, uid_t uid, const char *homedir)
{
int ret;
char **cells = NULL;
int index = 0;
if (homedir == NULL)
homedir = getenv("HOME");
if (homedir != NULL) {
char home[MaxPathLen];
snprintf(home, sizeof(home), "%s/.TheseCells", homedir);
find_cells(home, &cells, &index);
}
find_cells(_PATH_THESECELLS, &cells, &index);
find_cells(_PATH_THISCELL, &cells, &index);
find_cells(_PATH_ARLA_THESECELLS, &cells, &index);
find_cells(_PATH_ARLA_THISCELL, &cells, &index);
ret = afslog_cells(data, cells, index, uid, homedir);
while(index > 0)
free(cells[--index]);
free(cells);
return ret;
}
/* Find the realm associated with cell. Do this by opening
/usr/vice/etc/CellServDB and getting the realm-of-host for the
first VL-server for the cell.
This does not work when the VL-server is living in one realm, but
the cell it is serving is living in another realm.
Return 0 on success, -1 otherwise.
*/
int
_kafs_realm_of_cell(kafs_data *data, const char *cell, char **realm)
{
FILE *F;
char buf[1024];
char *p;
int ret = -1;
if ((F = fopen(_PATH_CELLSERVDB, "r"))
|| (F = fopen(_PATH_ARLA_CELLSERVDB, "r"))) {
while (fgets(buf, sizeof(buf), F)) {
if (buf[0] != '>')
continue; /* Not a cell name line, try next line */
if (strncmp(buf + 1, cell, strlen(cell)) == 0) {
/*
* We found the cell name we're looking for.
* Read next line on the form ip-address '#' hostname
*/
if (fgets(buf, sizeof(buf), F) == NULL)
break; /* Read failed, give up */
p = strchr(buf, '#');
if (p == NULL)
break; /* No '#', give up */
p++;
if (buf[strlen(buf) - 1] == '\n')
buf[strlen(buf) - 1] = '\0';
*realm = (*data->get_realm)(data, p);
if (*realm && **realm != '\0')
ret = 0;
break; /* Won't try any more */
}
}
fclose(F);
}
if (*realm == NULL && dns_find_cell(cell, buf, sizeof(buf)) == 0) {
*realm = strdup(krb_realmofhost(buf));
if(*realm != NULL)
ret = 0;
}
return ret;
}
int
_kafs_get_cred(kafs_data *data,
const char *cell,
const char *realm_hint,
const char *realm,
CREDENTIALS *c)
{
int ret = -1;
char *vl_realm;
char CELL[64];
/* We're about to find the the realm that holds the key for afs in
* the specified cell. The problem is that null-instance
* afs-principals are common and that hitting the wrong realm might
* yield the wrong afs key. The following assumptions were made.
*
* Any realm passed to us is preferred.
*
* If there is a realm with the same name as the cell, it is most
* likely the correct realm to talk to.
*
* In most (maybe even all) cases the database servers of the cell
* will live in the realm we are looking for.
*
* Try the local realm, but if the previous cases fail, this is
* really a long shot.
*
*/
/* comments on the ordering of these tests */
/* If the user passes a realm, she probably knows something we don't
* know and we should try afs@realm_hint (otherwise we're talking with a
* blondino and she might as well have it.)
*/
if (realm_hint) {
ret = (*data->get_cred)(data, AUTH_SUPERUSER, cell, realm_hint, c);
if (ret == 0) return 0;
ret = (*data->get_cred)(data, AUTH_SUPERUSER, "", realm_hint, c);
if (ret == 0) return 0;
}
foldup(CELL, cell);
/*
* If cell == realm we don't need no cross-cell authentication.
* Try afs@REALM.
*/
if (strcmp(CELL, realm) == 0) {
ret = (*data->get_cred)(data, AUTH_SUPERUSER, "", realm, c);
if (ret == 0) return 0;
/* Try afs.cell@REALM below. */
}
/*
* If the AFS servers have a file /usr/afs/etc/krb.conf containing
* REALM we still don't have to resort to cross-cell authentication.
* Try afs.cell@REALM.
*/
ret = (*data->get_cred)(data, AUTH_SUPERUSER, cell, realm, c);
if (ret == 0) return 0;
/*
* We failed to get ``first class tickets'' for afs,
* fall back to cross-cell authentication.
* Try afs@CELL.
* Try afs.cell@CELL.
*/
ret = (*data->get_cred)(data, AUTH_SUPERUSER, "", CELL, c);
if (ret == 0) return 0;
ret = (*data->get_cred)(data, AUTH_SUPERUSER, cell, CELL, c);
if (ret == 0) return 0;
/*
* Perhaps the cell doesn't correspond to any realm?
* Use realm of first volume location DB server.
* Try afs.cell@VL_REALM.
* Try afs@VL_REALM???
*/
if (_kafs_realm_of_cell(data, cell, &vl_realm) == 0
&& strcmp(vl_realm, realm) != 0
&& strcmp(vl_realm, CELL) != 0) {
ret = (*data->get_cred)(data, AUTH_SUPERUSER, cell, vl_realm, c);
if (ret)
ret = (*data->get_cred)(data, AUTH_SUPERUSER, "", vl_realm, c);
free(vl_realm);
if (ret == 0) return 0;
}
return ret;
}