/*-
* Copyright (c) 2005 Doug Rabson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <gssapi/gssapi.h>
#include <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mech_switch.h"
#include "utils.h"
#ifndef _PATH_GSS_MECH
#define _PATH_GSS_MECH "/etc/gss/mech"
#endif
struct _gss_mech_switch_list _gss_mechs =
SLIST_HEAD_INITIALIZER(_gss_mechs);
gss_OID_set _gss_mech_oids;
/*
* Convert a string containing an OID in 'dot' form
* (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
*/
static int
_gss_string_to_oid(const char* s, gss_OID oid)
{
int number_count, i, j;
int byte_count;
const char *p, *q;
char *res;
oid->length = 0;
oid->elements = NULL;
/*
* First figure out how many numbers in the oid, then
* calculate the compiled oid size.
*/
number_count = 0;
for (p = s; p; p = q) {
q = strchr(p, '.');
if (q) q = q + 1;
number_count++;
}
/*
* The first two numbers are in the first byte and each
* subsequent number is encoded in a variable byte sequence.
*/
if (number_count < 2)
return (EINVAL);
/*
* We do this in two passes. The first pass, we just figure
* out the size. Second time around, we actually encode the
* number.
*/
res = 0;
for (i = 0; i < 2; i++) {
byte_count = 0;
for (p = s, j = 0; p; p = q, j++) {
unsigned int number = 0;
/*
* Find the end of this number.
*/
q = strchr(p, '.');
if (q) q = q + 1;
/*
* Read the number of of the string. Don't
* bother with anything except base ten.
*/
while (*p && *p != '.') {
number = 10 * number + (*p - '0');
p++;
}
/*
* Encode the number. The first two numbers
* are packed into the first byte. Subsequent
* numbers are encoded in bytes seven bits at
* a time with the last byte having the high
* bit set.
*/
if (j == 0) {
if (res)
*res = number * 40;
} else if (j == 1) {
if (res) {
*res += number;
res++;
}
byte_count++;
} else if (j >= 2) {
/*
* The number is encoded in seven bit chunks.
*/
unsigned int t;
int bytes;
bytes = 0;
for (t = number; t; t >>= 7)
bytes++;
if (bytes == 0) bytes = 1;
while (bytes) {
if (res) {
int bit = 7*(bytes-1);
*res = (number >> bit) & 0x7f;
if (bytes != 1)
*res |= 0x80;
res++;
}
byte_count++;
bytes--;
}
}
}
if (!res) {
res = malloc(byte_count);
if (!res)
return (ENOMEM);
oid->length = byte_count;
oid->elements = res;
}
}
return (0);
}
#define SYM(name) \
do { \
snprintf(buf, sizeof(buf), "%s_%s", \
m->gm_name_prefix, #name); \
m->gm_ ## name = dlsym(so, buf); \
if (!m->gm_ ## name) { \
fprintf(stderr, "can't find symbol %s\n", buf); \
goto bad; \
} \
} while (0)
#define OPTSYM(name) \
do { \
snprintf(buf, sizeof(buf), "%s_%s", \
m->gm_name_prefix, #name); \
m->gm_ ## name = dlsym(so, buf); \
} while (0)
/*
* Load the mechanisms file (/etc/gss/mech).
*/
void
_gss_load_mech(void)
{
OM_uint32 major_status, minor_status;
FILE *fp;
char buf[256];
char *p;
char *name, *oid, *lib, *kobj;
struct _gss_mech_switch *m;
int count;
void *so;
const char *(*prefix_fn)(void);
if (SLIST_FIRST(&_gss_mechs))
return;
major_status = gss_create_empty_oid_set(&minor_status,
&_gss_mech_oids);
if (major_status)
return;
fp = fopen(_PATH_GSS_MECH, "r");
if (!fp) {
perror(_PATH_GSS_MECH);
return;
}
count = 0;
while (fgets(buf, sizeof(buf), fp)) {
if (*buf == '#')
continue;
p = buf;
name = strsep(&p, "\t\n ");
if (p) while (isspace(*p)) p++;
oid = strsep(&p, "\t\n ");
if (p) while (isspace(*p)) p++;
lib = strsep(&p, "\t\n ");
if (p) while (isspace(*p)) p++;
kobj = strsep(&p, "\t\n ");
if (!name || !oid || !lib || !kobj)
continue;
so = dlopen(lib, RTLD_LOCAL);
if (!so) {
fprintf(stderr, "dlopen: %s\n", dlerror());
continue;
}
m = malloc(sizeof(struct _gss_mech_switch));
if (!m)
break;
m->gm_so = so;
if (_gss_string_to_oid(oid, &m->gm_mech_oid)) {
free(m);
continue;
}
prefix_fn = (const char *(*)(void))
dlsym(so, "_gss_name_prefix");
if (prefix_fn)
m->gm_name_prefix = prefix_fn();
else
m->gm_name_prefix = "gss";
major_status = gss_add_oid_set_member(&minor_status,
&m->gm_mech_oid, &_gss_mech_oids);
if (major_status) {
free(m->gm_mech_oid.elements);
free(m);
continue;
}
SYM(acquire_cred);
SYM(release_cred);
SYM(init_sec_context);
SYM(accept_sec_context);
SYM(process_context_token);
SYM(delete_sec_context);
SYM(context_time);
SYM(get_mic);
SYM(verify_mic);
SYM(wrap);
SYM(unwrap);
SYM(display_status);
OPTSYM(indicate_mechs);
SYM(compare_name);
SYM(display_name);
SYM(import_name);
SYM(export_name);
SYM(release_name);
SYM(inquire_cred);
SYM(inquire_context);
SYM(wrap_size_limit);
SYM(add_cred);
SYM(inquire_cred_by_mech);
SYM(export_sec_context);
SYM(import_sec_context);
SYM(inquire_names_for_mech);
SYM(inquire_mechs_for_name);
SYM(canonicalize_name);
SYM(duplicate_name);
OPTSYM(inquire_sec_context_by_oid);
OPTSYM(inquire_cred_by_oid);
OPTSYM(set_sec_context_option);
OPTSYM(set_cred_option);
OPTSYM(pseudo_random);
OPTSYM(pname_to_uid);
SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
count++;
continue;
bad:
free(m->gm_mech_oid.elements);
free(m);
dlclose(so);
continue;
}
fclose(fp);
}
struct _gss_mech_switch *
_gss_find_mech_switch(gss_OID mech)
{
struct _gss_mech_switch *m;
_gss_load_mech();
SLIST_FOREACH(m, &_gss_mechs, gm_link) {
if (gss_oid_equal(&m->gm_mech_oid, mech))
return m;
}
return (0);
}
