freebsd-dev/sys/kgssapi/krb5/kcrypto.c

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Implement support for RPCSEC_GSS authentication to both the NFS client and server. This replaces the RPC implementation of the NFS client and server with the newer RPC implementation originally developed (actually ported from the userland sunrpc code) to support the NFS Lock Manager. I have tested this code extensively and I believe it is stable and that performance is at least equal to the legacy RPC implementation. The NFS code currently contains support for both the new RPC implementation and the older legacy implementation inherited from the original NFS codebase. The default is to use the new implementation - add the NFS_LEGACYRPC option to fall back to the old code. When I merge this support back to RELENG_7, I will probably change this so that users have to 'opt in' to get the new code. To use RPCSEC_GSS on either client or server, you must build a kernel which includes the KGSSAPI option and the crypto device. On the userland side, you must build at least a new libc, mountd, mount_nfs and gssd. You must install new versions of /etc/rc.d/gssd and /etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf. As long as gssd is running, you should be able to mount an NFS filesystem from a server that requires RPCSEC_GSS authentication. The mount itself can happen without any kerberos credentials but all access to the filesystem will be denied unless the accessing user has a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There is currently no support for situations where the ticket file is in a different place, such as when the user logged in via SSH and has delegated credentials from that login. This restriction is also present in Solaris and Linux. In theory, we could improve this in future, possibly using Brooks Davis' implementation of variant symlinks. Supporting RPCSEC_GSS on a server is nearly as simple. You must create service creds for the server in the form 'nfs/<fqdn>@<REALM>' and install them in /etc/krb5.keytab. The standard heimdal utility ktutil makes this fairly easy. After the service creds have been created, you can add a '-sec=krb5' option to /etc/exports and restart both mountd and nfsd. The only other difference an administrator should notice is that nfsd doesn't fork to create service threads any more. In normal operation, there will be two nfsd processes, one in userland waiting for TCP connections and one in the kernel handling requests. The latter process will create as many kthreads as required - these should be visible via 'top -H'. The code has some support for varying the number of service threads according to load but initially at least, nfsd uses a fixed number of threads according to the value supplied to its '-n' option. Sponsored by: Isilon Systems MFC after: 1 month
2008-11-03 10:38:00 +00:00
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
Implement support for RPCSEC_GSS authentication to both the NFS client and server. This replaces the RPC implementation of the NFS client and server with the newer RPC implementation originally developed (actually ported from the userland sunrpc code) to support the NFS Lock Manager. I have tested this code extensively and I believe it is stable and that performance is at least equal to the legacy RPC implementation. The NFS code currently contains support for both the new RPC implementation and the older legacy implementation inherited from the original NFS codebase. The default is to use the new implementation - add the NFS_LEGACYRPC option to fall back to the old code. When I merge this support back to RELENG_7, I will probably change this so that users have to 'opt in' to get the new code. To use RPCSEC_GSS on either client or server, you must build a kernel which includes the KGSSAPI option and the crypto device. On the userland side, you must build at least a new libc, mountd, mount_nfs and gssd. You must install new versions of /etc/rc.d/gssd and /etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf. As long as gssd is running, you should be able to mount an NFS filesystem from a server that requires RPCSEC_GSS authentication. The mount itself can happen without any kerberos credentials but all access to the filesystem will be denied unless the accessing user has a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There is currently no support for situations where the ticket file is in a different place, such as when the user logged in via SSH and has delegated credentials from that login. This restriction is also present in Solaris and Linux. In theory, we could improve this in future, possibly using Brooks Davis' implementation of variant symlinks. Supporting RPCSEC_GSS on a server is nearly as simple. You must create service creds for the server in the form 'nfs/<fqdn>@<REALM>' and install them in /etc/krb5.keytab. The standard heimdal utility ktutil makes this fairly easy. After the service creds have been created, you can add a '-sec=krb5' option to /etc/exports and restart both mountd and nfsd. The only other difference an administrator should notice is that nfsd doesn't fork to create service threads any more. In normal operation, there will be two nfsd processes, one in userland waiting for TCP connections and one in the kernel handling requests. The latter process will create as many kthreads as required - these should be visible via 'top -H'. The code has some support for varying the number of service threads according to load but initially at least, nfsd uses a fixed number of threads according to the value supplied to its '-n' option. Sponsored by: Isilon Systems MFC after: 1 month
2008-11-03 10:38:00 +00:00
* 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 <sys/sysctl.h>
Implement support for RPCSEC_GSS authentication to both the NFS client and server. This replaces the RPC implementation of the NFS client and server with the newer RPC implementation originally developed (actually ported from the userland sunrpc code) to support the NFS Lock Manager. I have tested this code extensively and I believe it is stable and that performance is at least equal to the legacy RPC implementation. The NFS code currently contains support for both the new RPC implementation and the older legacy implementation inherited from the original NFS codebase. The default is to use the new implementation - add the NFS_LEGACYRPC option to fall back to the old code. When I merge this support back to RELENG_7, I will probably change this so that users have to 'opt in' to get the new code. To use RPCSEC_GSS on either client or server, you must build a kernel which includes the KGSSAPI option and the crypto device. On the userland side, you must build at least a new libc, mountd, mount_nfs and gssd. You must install new versions of /etc/rc.d/gssd and /etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf. As long as gssd is running, you should be able to mount an NFS filesystem from a server that requires RPCSEC_GSS authentication. The mount itself can happen without any kerberos credentials but all access to the filesystem will be denied unless the accessing user has a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There is currently no support for situations where the ticket file is in a different place, such as when the user logged in via SSH and has delegated credentials from that login. This restriction is also present in Solaris and Linux. In theory, we could improve this in future, possibly using Brooks Davis' implementation of variant symlinks. Supporting RPCSEC_GSS on a server is nearly as simple. You must create service creds for the server in the form 'nfs/<fqdn>@<REALM>' and install them in /etc/krb5.keytab. The standard heimdal utility ktutil makes this fairly easy. After the service creds have been created, you can add a '-sec=krb5' option to /etc/exports and restart both mountd and nfsd. The only other difference an administrator should notice is that nfsd doesn't fork to create service threads any more. In normal operation, there will be two nfsd processes, one in userland waiting for TCP connections and one in the kernel handling requests. The latter process will create as many kthreads as required - these should be visible via 'top -H'. The code has some support for varying the number of service threads according to load but initially at least, nfsd uses a fixed number of threads according to the value supplied to its '-n' option. Sponsored by: Isilon Systems MFC after: 1 month
2008-11-03 10:38:00 +00:00
#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 timeval krb5_warn_interval = { .tv_sec = 3600, .tv_usec = 0 };
SYSCTL_TIMEVAL_SEC(_kern, OID_AUTO, kgssapi_warn_interval, CTLFLAG_RW,
&krb5_warn_interval,
"Delay in seconds between warnings of deprecated KGSSAPI crypto.");
Implement support for RPCSEC_GSS authentication to both the NFS client and server. This replaces the RPC implementation of the NFS client and server with the newer RPC implementation originally developed (actually ported from the userland sunrpc code) to support the NFS Lock Manager. I have tested this code extensively and I believe it is stable and that performance is at least equal to the legacy RPC implementation. The NFS code currently contains support for both the new RPC implementation and the older legacy implementation inherited from the original NFS codebase. The default is to use the new implementation - add the NFS_LEGACYRPC option to fall back to the old code. When I merge this support back to RELENG_7, I will probably change this so that users have to 'opt in' to get the new code. To use RPCSEC_GSS on either client or server, you must build a kernel which includes the KGSSAPI option and the crypto device. On the userland side, you must build at least a new libc, mountd, mount_nfs and gssd. You must install new versions of /etc/rc.d/gssd and /etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf. As long as gssd is running, you should be able to mount an NFS filesystem from a server that requires RPCSEC_GSS authentication. The mount itself can happen without any kerberos credentials but all access to the filesystem will be denied unless the accessing user has a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There is currently no support for situations where the ticket file is in a different place, such as when the user logged in via SSH and has delegated credentials from that login. This restriction is also present in Solaris and Linux. In theory, we could improve this in future, possibly using Brooks Davis' implementation of variant symlinks. Supporting RPCSEC_GSS on a server is nearly as simple. You must create service creds for the server in the form 'nfs/<fqdn>@<REALM>' and install them in /etc/krb5.keytab. The standard heimdal utility ktutil makes this fairly easy. After the service creds have been created, you can add a '-sec=krb5' option to /etc/exports and restart both mountd and nfsd. The only other difference an administrator should notice is that nfsd doesn't fork to create service threads any more. In normal operation, there will be two nfsd processes, one in userland waiting for TCP connections and one in the kernel handling requests. The latter process will create as many kthreads as required - these should be visible via 'top -H'. The code has some support for varying the number of service threads according to load but initially at least, nfsd uses a fixed number of threads according to the value supplied to its '-n' option. Sponsored by: Isilon Systems MFC after: 1 month
2008-11-03 10:38:00 +00:00
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);
Implement support for RPCSEC_GSS authentication to both the NFS client and server. This replaces the RPC implementation of the NFS client and server with the newer RPC implementation originally developed (actually ported from the userland sunrpc code) to support the NFS Lock Manager. I have tested this code extensively and I believe it is stable and that performance is at least equal to the legacy RPC implementation. The NFS code currently contains support for both the new RPC implementation and the older legacy implementation inherited from the original NFS codebase. The default is to use the new implementation - add the NFS_LEGACYRPC option to fall back to the old code. When I merge this support back to RELENG_7, I will probably change this so that users have to 'opt in' to get the new code. To use RPCSEC_GSS on either client or server, you must build a kernel which includes the KGSSAPI option and the crypto device. On the userland side, you must build at least a new libc, mountd, mount_nfs and gssd. You must install new versions of /etc/rc.d/gssd and /etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf. As long as gssd is running, you should be able to mount an NFS filesystem from a server that requires RPCSEC_GSS authentication. The mount itself can happen without any kerberos credentials but all access to the filesystem will be denied unless the accessing user has a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There is currently no support for situations where the ticket file is in a different place, such as when the user logged in via SSH and has delegated credentials from that login. This restriction is also present in Solaris and Linux. In theory, we could improve this in future, possibly using Brooks Davis' implementation of variant symlinks. Supporting RPCSEC_GSS on a server is nearly as simple. You must create service creds for the server in the form 'nfs/<fqdn>@<REALM>' and install them in /etc/krb5.keytab. The standard heimdal utility ktutil makes this fairly easy. After the service creds have been created, you can add a '-sec=krb5' option to /etc/exports and restart both mountd and nfsd. The only other difference an administrator should notice is that nfsd doesn't fork to create service threads any more. In normal operation, there will be two nfsd processes, one in userland waiting for TCP connections and one in the kernel handling requests. The latter process will create as many kthreads as required - these should be visible via 'top -H'. The code has some support for varying the number of service threads according to load but initially at least, nfsd uses a fixed number of threads according to the value supplied to its '-n' option. Sponsored by: Isilon Systems MFC after: 1 month
2008-11-03 10:38:00 +00:00
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));
}