263 lines
6.4 KiB
C
263 lines
6.4 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*
|
|
* Copyright (c) 2008 Isilon Inc http://www.isilon.com/
|
|
* Authors: Doug Rabson <dfr@rabson.org>
|
|
* Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#include <sys/param.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/kobj.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <kgssapi/gssapi.h>
|
|
#include <kgssapi/gssapi_impl.h>
|
|
|
|
#include "kcrypto.h"
|
|
|
|
static struct krb5_encryption_class *krb5_encryption_classes[] = {
|
|
&krb5_aes128_encryption_class,
|
|
&krb5_aes256_encryption_class,
|
|
NULL
|
|
};
|
|
|
|
struct krb5_encryption_class *
|
|
krb5_find_encryption_class(int etype)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; krb5_encryption_classes[i]; i++) {
|
|
if (krb5_encryption_classes[i]->ec_type == etype)
|
|
return (krb5_encryption_classes[i]);
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
struct krb5_key_state *
|
|
krb5_create_key(const struct krb5_encryption_class *ec)
|
|
{
|
|
struct krb5_key_state *ks;
|
|
|
|
ks = malloc(sizeof(struct krb5_key_state), M_GSSAPI, M_WAITOK);
|
|
ks->ks_class = ec;
|
|
refcount_init(&ks->ks_refs, 1);
|
|
ks->ks_key = malloc(ec->ec_keylen, M_GSSAPI, M_WAITOK);
|
|
ec->ec_init(ks);
|
|
|
|
return (ks);
|
|
}
|
|
|
|
void
|
|
krb5_free_key(struct krb5_key_state *ks)
|
|
{
|
|
|
|
if (refcount_release(&ks->ks_refs)) {
|
|
ks->ks_class->ec_destroy(ks);
|
|
bzero(ks->ks_key, ks->ks_class->ec_keylen);
|
|
free(ks->ks_key, M_GSSAPI);
|
|
free(ks, M_GSSAPI);
|
|
}
|
|
}
|
|
|
|
static size_t
|
|
gcd(size_t a, size_t b)
|
|
{
|
|
|
|
if (b == 0)
|
|
return (a);
|
|
return gcd(b, a % b);
|
|
}
|
|
|
|
static size_t
|
|
lcm(size_t a, size_t b)
|
|
{
|
|
return ((a * b) / gcd(a, b));
|
|
}
|
|
|
|
/*
|
|
* Rotate right 13 of a variable precision number in 'in', storing the
|
|
* result in 'out'. The number is assumed to be big-endian in memory
|
|
* representation.
|
|
*/
|
|
static void
|
|
krb5_rotate_right_13(uint8_t *out, uint8_t *in, size_t numlen)
|
|
{
|
|
uint32_t carry;
|
|
size_t i;
|
|
|
|
/*
|
|
* Special case when numlen == 1. A rotate right 13 of a
|
|
* single byte number changes to a rotate right 5.
|
|
*/
|
|
if (numlen == 1) {
|
|
carry = in[0] >> 5;
|
|
out[0] = (in[0] << 3) | carry;
|
|
return;
|
|
}
|
|
|
|
carry = ((in[numlen - 2] & 31) << 8) | in[numlen - 1];
|
|
for (i = 2; i < numlen; i++) {
|
|
out[i] = ((in[i - 2] & 31) << 3) | (in[i - 1] >> 5);
|
|
}
|
|
out[1] = ((carry & 31) << 3) | (in[0] >> 5);
|
|
out[0] = carry >> 5;
|
|
}
|
|
|
|
/*
|
|
* Add two variable precision numbers in big-endian representation
|
|
* using ones-complement arithmetic.
|
|
*/
|
|
static void
|
|
krb5_ones_complement_add(uint8_t *out, const uint8_t *in, size_t len)
|
|
{
|
|
int n, i;
|
|
|
|
/*
|
|
* First calculate the 2s complement sum, remembering the
|
|
* carry.
|
|
*/
|
|
n = 0;
|
|
for (i = len - 1; i >= 0; i--) {
|
|
n = out[i] + in[i] + n;
|
|
out[i] = n;
|
|
n >>= 8;
|
|
}
|
|
/*
|
|
* Then add back the carry.
|
|
*/
|
|
for (i = len - 1; n && i >= 0; i--) {
|
|
n = out[i] + n;
|
|
out[i] = n;
|
|
n >>= 8;
|
|
}
|
|
}
|
|
|
|
static void
|
|
krb5_n_fold(uint8_t *out, size_t outlen, const uint8_t *in, size_t inlen)
|
|
{
|
|
size_t tmplen;
|
|
uint8_t *tmp;
|
|
size_t i;
|
|
uint8_t *p;
|
|
|
|
tmplen = lcm(inlen, outlen);
|
|
tmp = malloc(tmplen, M_GSSAPI, M_WAITOK);
|
|
|
|
bcopy(in, tmp, inlen);
|
|
for (i = inlen, p = tmp; i < tmplen; i += inlen, p += inlen) {
|
|
krb5_rotate_right_13(p + inlen, p, inlen);
|
|
}
|
|
bzero(out, outlen);
|
|
for (i = 0, p = tmp; i < tmplen; i += outlen, p += outlen) {
|
|
krb5_ones_complement_add(out, p, outlen);
|
|
}
|
|
free(tmp, M_GSSAPI);
|
|
}
|
|
|
|
struct krb5_key_state *
|
|
krb5_derive_key(struct krb5_key_state *inkey,
|
|
void *constant, size_t constantlen)
|
|
{
|
|
struct krb5_key_state *dk;
|
|
const struct krb5_encryption_class *ec = inkey->ks_class;
|
|
uint8_t *folded;
|
|
uint8_t *bytes, *p, *q;
|
|
struct mbuf *m;
|
|
int randomlen, i;
|
|
|
|
/*
|
|
* Expand the constant to blocklen bytes.
|
|
*/
|
|
folded = malloc(ec->ec_blocklen, M_GSSAPI, M_WAITOK);
|
|
krb5_n_fold(folded, ec->ec_blocklen, constant, constantlen);
|
|
|
|
/*
|
|
* Generate enough bytes for keybits rounded up to a multiple
|
|
* of blocklen.
|
|
*/
|
|
randomlen = roundup(ec->ec_keybits / 8, ec->ec_blocklen);
|
|
bytes = malloc(randomlen, M_GSSAPI, M_WAITOK);
|
|
MGET(m, M_WAITOK, MT_DATA);
|
|
m->m_len = ec->ec_blocklen;
|
|
for (i = 0, p = bytes, q = folded; i < randomlen;
|
|
q = p, i += ec->ec_blocklen, p += ec->ec_blocklen) {
|
|
bcopy(q, m->m_data, ec->ec_blocklen);
|
|
krb5_encrypt(inkey, m, 0, ec->ec_blocklen, NULL, 0);
|
|
bcopy(m->m_data, p, ec->ec_blocklen);
|
|
}
|
|
m_free(m);
|
|
|
|
dk = krb5_create_key(ec);
|
|
krb5_random_to_key(dk, bytes);
|
|
|
|
free(folded, M_GSSAPI);
|
|
free(bytes, M_GSSAPI);
|
|
|
|
return (dk);
|
|
}
|
|
|
|
static struct krb5_key_state *
|
|
krb5_get_usage_key(struct krb5_key_state *basekey, int usage, int which)
|
|
{
|
|
const struct krb5_encryption_class *ec = basekey->ks_class;
|
|
|
|
if (ec->ec_flags & EC_DERIVED_KEYS) {
|
|
uint8_t constant[5];
|
|
|
|
constant[0] = usage >> 24;
|
|
constant[1] = usage >> 16;
|
|
constant[2] = usage >> 8;
|
|
constant[3] = usage;
|
|
constant[4] = which;
|
|
return (krb5_derive_key(basekey, constant, 5));
|
|
} else {
|
|
refcount_acquire(&basekey->ks_refs);
|
|
return (basekey);
|
|
}
|
|
}
|
|
|
|
struct krb5_key_state *
|
|
krb5_get_encryption_key(struct krb5_key_state *basekey, int usage)
|
|
{
|
|
|
|
return (krb5_get_usage_key(basekey, usage, 0xaa));
|
|
}
|
|
|
|
struct krb5_key_state *
|
|
krb5_get_integrity_key(struct krb5_key_state *basekey, int usage)
|
|
{
|
|
|
|
return (krb5_get_usage_key(basekey, usage, 0x55));
|
|
}
|
|
|
|
struct krb5_key_state *
|
|
krb5_get_checksum_key(struct krb5_key_state *basekey, int usage)
|
|
{
|
|
|
|
return (krb5_get_usage_key(basekey, usage, 0x99));
|
|
}
|