freebsd-skq/sys/kgssapi/krb5/kcrypto.c
Pedro F. Giffuni 4de8ade94c sys/kgssapi: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:49:00 +00:00

268 lines
6.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/kobj.h>
#include <sys/mbuf.h>
#include <kgssapi/gssapi.h>
#include <kgssapi/gssapi_impl.h>
#include "kcrypto.h"
static struct krb5_encryption_class *krb5_encryption_classes[] = {
&krb5_des_encryption_class,
&krb5_des3_encryption_class,
&krb5_aes128_encryption_class,
&krb5_aes256_encryption_class,
&krb5_arcfour_encryption_class,
&krb5_arcfour_56_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));
}