The branch, master has been updated
via 5e492f8 s4 dns: Allow configuring signed updates
via 2b17566 s4 dns: Make sure to remember incoming tkey name
via 53f602c s4 dns: Verify incoming TSIG signatures
via 7fe5e2c s4 dns: Handle GSS-TSIG signature creation
via 956f41b s4 dns: When we got a TKEY, we need to remember which key
to use for signing
via e81d026 s4 dns: TKEY record needs to remember incoming algorithm
via c0e6a4b s4 dns: Move dns_find_tkey to an extra file
via 22fda8c s4 dns: Create IDL entry for TSIG-like record needed for
signature check
from 58d8d94 s4-dns: Fix linking the dns service.
http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit 5e492f8d324d269c2eb0e12f6dca2cb8133c4b8e
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 01:27:00 2012 +0200
s4 dns: Allow configuring signed updates
Autobuild-User(master): Kai Blin <k...@samba.org>
Autobuild-Date(master): Wed Sep 5 20:42:46 CEST 2012 on sn-devel-104
commit 2b17566e8902a326253257e1665b3b7a49e1aa26
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 01:26:16 2012 +0200
s4 dns: Make sure to remember incoming tkey name
commit 53f602c3744c0952f3385a39d5984d5a47b9905c
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 08:34:49 2012 +0200
s4 dns: Verify incoming TSIG signatures
commit 7fe5e2cdcb17cee06ebde2717439c0aa964ac026
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 08:34:04 2012 +0200
s4 dns: Handle GSS-TSIG signature creation
commit 956f41bddf946d5e1e35f06632f40e7ac71b6588
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 08:29:38 2012 +0200
s4 dns: When we got a TKEY, we need to remember which key to use for signing
commit e81d026576cd1df9eb406c8ef0b0f27b7188b8ea
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 08:27:28 2012 +0200
s4 dns: TKEY record needs to remember incoming algorithm
Samba3 (and older windows versions) use gss.microsoft.com, win7 (and the
RFC) use gss-tsig
commit c0e6a4b1b07c7aff49f19c4d8cf3de1ff020afab
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 08:24:52 2012 +0200
s4 dns: Move dns_find_tkey to an extra file
commit 22fda8cb155041556a51106e5b1f058378c2c05b
Author: Kai Blin <k...@samba.org>
Date: Wed Sep 5 08:16:43 2012 +0200
s4 dns: Create IDL entry for TSIG-like record needed for signature check
-----------------------------------------------------------------------
Summary of changes:
librpc/idl/dns.idl | 14 ++
source4/dns_server/dns_crypto.c | 359 ++++++++++++++++++++++++++++++++++++++
source4/dns_server/dns_query.c | 110 ++++++------
source4/dns_server/dns_server.c | 20 ++
source4/dns_server/dns_server.h | 18 ++
source4/dns_server/dns_update.c | 7 +-
source4/dns_server/dns_utils.c | 2 +
source4/dns_server/wscript_build | 2 +-
8 files changed, 472 insertions(+), 60 deletions(-)
create mode 100644 source4/dns_server/dns_crypto.c
Changeset truncated at 500 lines:
diff --git a/librpc/idl/dns.idl b/librpc/idl/dns.idl
index a92c418..984f2b3 100644
--- a/librpc/idl/dns.idl
+++ b/librpc/idl/dns.idl
@@ -192,6 +192,20 @@ interface dns
uint8 other_data[other_size];
} dns_tsig_record;
+ typedef [flag(NDR_NOALIGN|NDR_BIG_ENDIAN|NDR_PAHEX),public] struct {
+ dns_string name;
+ dns_qclass rr_class;
+ uint32 ttl;
+ dns_string algorithm_name;
+ uint16 time_prefix; /* 0 until February 2106*/
+ uint32 time;
+ uint16 fudge;
+ uint16 original_id;
+ uint16 error;
+ uint16 other_size;
+ uint8 other_data[other_size];
+ } dns_fake_tsig_rec;
+
typedef [nodiscriminant,public,flag(NDR_NOALIGN)] union {
[case(DNS_QTYPE_A)] ipv4address ipv4_record;
[case(DNS_QTYPE_NS)] dns_string ns_record;
diff --git a/source4/dns_server/dns_crypto.c b/source4/dns_server/dns_crypto.c
new file mode 100644
index 0000000..7362adc
--- /dev/null
+++ b/source4/dns_server/dns_crypto.c
@@ -0,0 +1,359 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ DNS server handler for signed packets
+
+ Copyright (C) 2012 Kai Blin <k...@samba.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "lib/crypto/hmacmd5.h"
+#include "system/network.h"
+#include "librpc/ndr/libndr.h"
+#include "librpc/gen_ndr/ndr_dns.h"
+#include "dns_server/dns_server.h"
+#include "libcli/util/ntstatus.h"
+#include "auth/auth.h"
+#include "auth/gensec/gensec.h"
+
+static WERROR dns_copy_tsig(TALLOC_CTX *mem_ctx,
+ struct dns_res_rec *old,
+ struct dns_res_rec *new_rec)
+{
+ new_rec->name = talloc_strdup(mem_ctx, old->name);
+ W_ERROR_HAVE_NO_MEMORY(new_rec->name);
+
+ new_rec->rr_type = old->rr_type;
+ new_rec->rr_class = old->rr_class;
+ new_rec->ttl = old->ttl;
+ new_rec->length = old->length;
+ new_rec->rdata.tsig_record.algorithm_name = talloc_strdup(mem_ctx,
+ old->rdata.tsig_record.algorithm_name);
+ W_ERROR_HAVE_NO_MEMORY(new_rec->rdata.tsig_record.algorithm_name);
+
+ new_rec->rdata.tsig_record.time_prefix =
old->rdata.tsig_record.time_prefix;
+ new_rec->rdata.tsig_record.time = old->rdata.tsig_record.time;
+ new_rec->rdata.tsig_record.fudge = old->rdata.tsig_record.fudge;
+ new_rec->rdata.tsig_record.mac_size = old->rdata.tsig_record.mac_size;
+ new_rec->rdata.tsig_record.mac = talloc_memdup(mem_ctx,
+ old->rdata.tsig_record.mac,
+ old->rdata.tsig_record.mac_size);
+ W_ERROR_HAVE_NO_MEMORY(new_rec->rdata.tsig_record.mac);
+
+ new_rec->rdata.tsig_record.original_id =
old->rdata.tsig_record.original_id;
+ new_rec->rdata.tsig_record.error = old->rdata.tsig_record.error;
+ new_rec->rdata.tsig_record.other_size =
old->rdata.tsig_record.other_size;
+ new_rec->rdata.tsig_record.other_data = talloc_memdup(mem_ctx,
+ old->rdata.tsig_record.other_data,
+ old->rdata.tsig_record.other_size);
+ W_ERROR_HAVE_NO_MEMORY(new_rec->rdata.tsig_record.other_data);
+
+ return WERR_OK;
+}
+
+struct dns_server_tkey *dns_find_tkey(struct dns_server_tkey_store *store,
+ const char *name)
+{
+ struct dns_server_tkey *tkey = NULL;
+ uint16_t i = 0;
+
+ do {
+ struct dns_server_tkey *tmp_key = store->tkeys[i];
+
+ i++;
+ i %= TKEY_BUFFER_SIZE;
+
+ if (tmp_key == NULL) {
+ continue;
+ }
+ if (dns_name_equal(name, tmp_key->name)) {
+ tkey = tmp_key;
+ break;
+ }
+ } while (i != 0);
+
+ return tkey;
+}
+
+WERROR dns_verify_tsig(struct dns_server *dns,
+ TALLOC_CTX *mem_ctx,
+ struct dns_request_state *state,
+ struct dns_name_packet *packet,
+ DATA_BLOB *in)
+{
+ WERROR werror;
+ NTSTATUS status;
+ enum ndr_err_code ndr_err;
+ bool found_tsig = false;
+ uint16_t i, arcount = 0;
+ DATA_BLOB tsig_blob, fake_tsig_blob, sig;
+ uint8_t *buffer = NULL;
+ size_t buffer_len = 0, packet_len = 0;
+ struct dns_server_tkey *tkey = NULL;
+ struct dns_fake_tsig_rec *check_rec = talloc_zero(mem_ctx,
+ struct dns_fake_tsig_rec);
+
+
+ /* Find the first TSIG record in the additional records */
+ for (i=0; i < packet->arcount; i++) {
+ if (packet->additional[i].rr_type == DNS_QTYPE_TSIG) {
+ found_tsig = true;
+ break;
+ }
+ }
+
+ if (!found_tsig) {
+ return WERR_OK;
+ }
+
+ /* The TSIG record needs to be the last additional record */
+ if (found_tsig && i + 1 != packet->arcount) {
+ DEBUG(0, ("TSIG record not the last additional record!\n"));
+ return DNS_ERR(FORMAT_ERROR);
+ }
+
+ /* We got a TSIG, so we need to sign our reply */
+ state->sign = true;
+
+ state->tsig = talloc_zero(mem_ctx, struct dns_res_rec);
+ if (state->tsig == NULL) {
+ return WERR_NOMEM;
+ }
+
+ werror = dns_copy_tsig(state->tsig, &packet->additional[i],
+ state->tsig);
+ if (!W_ERROR_IS_OK(werror)) {
+ return werror;
+ }
+
+ packet->arcount--;
+
+ tkey = dns_find_tkey(dns->tkeys, state->tsig->name);
+ if (tkey == NULL) {
+ state->tsig_error = DNS_RCODE_BADKEY;
+ return DNS_ERR(NOTAUTH);
+ }
+
+ /* FIXME: check TSIG here */
+ if (check_rec == NULL) {
+ return WERR_NOMEM;
+ }
+
+ /* first build and verify check packet */
+ check_rec->name = talloc_strdup(check_rec, tkey->name);
+ if (check_rec->name == NULL) {
+ return WERR_NOMEM;
+ }
+ check_rec->rr_class = DNS_QCLASS_ANY;
+ check_rec->ttl = 0;
+ check_rec->algorithm_name = talloc_strdup(check_rec, tkey->algorithm);
+ if (check_rec->algorithm_name == NULL) {
+ return WERR_NOMEM;
+ }
+ check_rec->time_prefix = 0;
+ check_rec->time = state->tsig->rdata.tsig_record.time;
+ check_rec->fudge = state->tsig->rdata.tsig_record.fudge;
+ check_rec->error = 0;
+ check_rec->other_size = 0;
+ check_rec->other_data = NULL;
+
+ ndr_err = ndr_push_struct_blob(&tsig_blob, mem_ctx, state->tsig,
+ (ndr_push_flags_fn_t)ndr_push_dns_res_rec);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ DEBUG(1, ("Failed to push packet: %s!\n",
+ ndr_errstr(ndr_err)));
+ return DNS_ERR(SERVER_FAILURE);
+ }
+
+ ndr_err = ndr_push_struct_blob(&fake_tsig_blob, mem_ctx, check_rec,
+ (ndr_push_flags_fn_t)ndr_push_dns_fake_tsig_rec);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ DEBUG(1, ("Failed to push packet: %s!\n",
+ ndr_errstr(ndr_err)));
+ return DNS_ERR(SERVER_FAILURE);
+ }
+
+ /* we need to work some magic here. we need to keep the input packet
+ * exactly like we got it, but we need to cut off the tsig record */
+ packet_len = in->length - tsig_blob.length;
+ buffer_len = packet_len + fake_tsig_blob.length;
+ buffer = talloc_zero_array(mem_ctx, uint8_t, buffer_len);
+ if (buffer == NULL) {
+ return WERR_NOMEM;
+ }
+
+ memcpy(buffer, in->data, packet_len);
+ memcpy(buffer + packet_len, fake_tsig_blob.data, fake_tsig_blob.length);
+
+ sig.length = state->tsig->rdata.tsig_record.mac_size;
+ sig.data = talloc_memdup(mem_ctx, state->tsig->rdata.tsig_record.mac,
sig.length);
+ if (sig.data == NULL) {
+ return WERR_NOMEM;
+ }
+
+ /*FIXME: Why is there too much padding? */
+ buffer_len -= 2;
+
+ /* Now we also need to count down the additional record counter */
+ arcount = RSVAL(buffer, 10);
+ RSSVAL(buffer, 10, arcount-1);
+
+ status = gensec_check_packet(tkey->gensec, buffer, buffer_len,
+ buffer, buffer_len, &sig);
+ if (NT_STATUS_EQUAL(NT_STATUS_ACCESS_DENIED, status)) {
+ return DNS_ERR(BADKEY);
+ }
+
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0, ("Verifying tsig failed: %s\n", nt_errstr(status)));
+ return ntstatus_to_werror(status);
+ }
+
+ state->authenticated = true;
+ state->key_name = talloc_strdup(mem_ctx, tkey->name);
+ if (state->key_name == NULL) {
+ return WERR_NOMEM;
+ }
+
+ return WERR_OK;
+}
+
+WERROR dns_sign_tsig(struct dns_server *dns,
+ TALLOC_CTX *mem_ctx,
+ struct dns_request_state *state,
+ struct dns_name_packet *packet,
+ uint16_t error)
+{
+ WERROR werror;
+ NTSTATUS status;
+ enum ndr_err_code ndr_err;
+ time_t current_time = time(NULL);
+ DATA_BLOB packet_blob, tsig_blob, sig;
+ uint8_t *buffer = NULL;
+ size_t buffer_len = 0;
+ struct dns_server_tkey * tkey = NULL;
+ struct dns_res_rec *tsig = talloc_zero(mem_ctx, struct dns_res_rec);
+
+ struct dns_fake_tsig_rec *check_rec = talloc_zero(mem_ctx,
+ struct dns_fake_tsig_rec);
+
+ if (tsig == NULL) {
+ return WERR_NOMEM;
+ }
+
+ if (check_rec == NULL) {
+ return WERR_NOMEM;
+ }
+
+ tkey = dns_find_tkey(dns->tkeys, state->key_name);
+ if (tkey == NULL) {
+ /* FIXME: read up on what to do when we can't find a key */
+ return WERR_OK;
+ }
+
+ /* first build and verify check packet */
+ check_rec->name = talloc_strdup(check_rec, tkey->name);
+ if (check_rec->name == NULL) {
+ return WERR_NOMEM;
+ }
+ check_rec->rr_class = DNS_QCLASS_ANY;
+ check_rec->ttl = 0;
+ check_rec->algorithm_name = talloc_strdup(check_rec, tkey->algorithm);
+ if (check_rec->algorithm_name == NULL) {
+ return WERR_NOMEM;
+ }
+ check_rec->time_prefix = 0;
+ check_rec->time = current_time;
+ check_rec->fudge = 300;
+ check_rec->error = state->tsig_error;
+ check_rec->other_size = 0;
+ check_rec->other_data = NULL;
+
+ ndr_err = ndr_push_struct_blob(&packet_blob, mem_ctx, packet,
+ (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ DEBUG(1, ("Failed to push packet: %s!\n",
+ ndr_errstr(ndr_err)));
+ return DNS_ERR(SERVER_FAILURE);
+ }
+
+ ndr_err = ndr_push_struct_blob(&tsig_blob, mem_ctx, check_rec,
+ (ndr_push_flags_fn_t)ndr_push_dns_fake_tsig_rec);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ DEBUG(1, ("Failed to push packet: %s!\n",
+ ndr_errstr(ndr_err)));
+ return DNS_ERR(SERVER_FAILURE);
+ }
+
+ buffer_len = packet_blob.length + tsig_blob.length;
+ buffer = talloc_zero_array(mem_ctx, uint8_t, buffer_len);
+ if (buffer == NULL) {
+ return WERR_NOMEM;
+ }
+
+ memcpy(buffer, packet_blob.data, packet_blob.length);
+ memcpy(buffer+packet_blob.length, tsig_blob.data, tsig_blob.length);
+
+
+ status = gensec_sign_packet(tkey->gensec, mem_ctx, buffer, buffer_len,
+ buffer, buffer_len, &sig);
+ if (!NT_STATUS_IS_OK(status)) {
+ return ntstatus_to_werror(status);
+ }
+
+ tsig->name = talloc_strdup(tsig, check_rec->name);
+ if (tsig->name == NULL) {
+ return WERR_NOMEM;
+ }
+ tsig->rr_class = check_rec->rr_class;
+ tsig->rr_type = DNS_QTYPE_TSIG;
+ tsig->ttl = 0;
+ tsig->length = UINT16_MAX;
+ tsig->rdata.tsig_record.algorithm_name = talloc_strdup(tsig,
+ check_rec->algorithm_name);
+ tsig->rdata.tsig_record.time_prefix = check_rec->time_prefix;
+ tsig->rdata.tsig_record.time = check_rec->time;
+ tsig->rdata.tsig_record.fudge = check_rec->fudge;
+ tsig->rdata.tsig_record.error = state->tsig_error;
+ tsig->rdata.tsig_record.original_id = packet->id;
+ tsig->rdata.tsig_record.other_size = 0;
+ tsig->rdata.tsig_record.other_data = NULL;
+ tsig->rdata.tsig_record.mac_size = sig.length;
+ tsig->rdata.tsig_record.mac = talloc_memdup(tsig, sig.data, sig.length);
+
+
+ if (packet->arcount == 0) {
+ packet->additional = talloc_zero(mem_ctx, struct dns_res_rec);
+ if (packet->additional == NULL) {
+ return WERR_NOMEM;
+ }
+ }
+ packet->additional = talloc_realloc(mem_ctx, packet->additional,
+ struct dns_res_rec,
+ packet->arcount + 1);
+ if (packet->additional == NULL) {
+ return WERR_NOMEM;
+ }
+
+ werror = dns_copy_tsig(mem_ctx, tsig,
+ &packet->additional[packet->arcount]);
+ if (!W_ERROR_IS_OK(werror)) {
+ return werror;
+ }
+ packet->arcount++;
+
+ return WERR_OK;
+}
diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c
index 530b7b2..98ebc63 100644
--- a/source4/dns_server/dns_query.c
+++ b/source4/dns_server/dns_query.c
@@ -320,62 +320,9 @@ static WERROR handle_question(struct dns_server *dns,
return WERR_OK;
}
-static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
- struct dns_server *dns,
- struct dns_server_tkey *tkey,
- const DATA_BLOB *key,
- DATA_BLOB *reply,
- uint16_t *dns_auth_error)
-{
- NTSTATUS status;
-
- status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
- *key, reply);
-
- if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
- *dns_auth_error = DNS_RCODE_OK;
- return status;
- }
-
- if (NT_STATUS_IS_OK(status)) {
-
- status = gensec_session_info(tkey->gensec, tkey,
&tkey->session_info);
- if (!NT_STATUS_IS_OK(status)) {
- *dns_auth_error = DNS_RCODE_BADKEY;
- return status;
- }
- *dns_auth_error = DNS_RCODE_OK;
- }
-
- return status;
-}
-
-static struct dns_server_tkey *find_tkey(struct dns_server_tkey_store *store,
- const char *name)
-{
- struct dns_server_tkey *tkey = NULL;
- uint16_t i = 0;
-
- do {
- struct dns_server_tkey *tmp_key = store->tkeys[i];
-
- i++;
- i %= TKEY_BUFFER_SIZE;
-
- if (tmp_key == NULL) {
- continue;
- }
- if (dns_name_equal(name, tmp_key->name)) {
- tkey = tmp_key;
- break;
- }
- } while (i != 0);
-
- return tkey;
-}
-
static NTSTATUS create_tkey(struct dns_server *dns,
const char* name,
+ const char* algorithm,
struct dns_server_tkey **tkey)
{
NTSTATUS status;
@@ -392,6 +339,11 @@ static NTSTATUS create_tkey(struct dns_server *dns,
return NT_STATUS_NO_MEMORY;
}
+ k->algorithm = talloc_strdup(k, algorithm);
+ if (k->algorithm == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
status = samba_server_gensec_start(k,
dns->task->event_ctx,
dns->task->msg_ctx,
@@ -428,9 +380,40 @@ static NTSTATUS create_tkey(struct dns_server *dns,
return NT_STATUS_OK;
}
+static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
+ struct dns_server *dns,
+ struct dns_server_tkey *tkey,
+ const DATA_BLOB *key,
+ DATA_BLOB *reply,
+ uint16_t *dns_auth_error)
+{
+ NTSTATUS status;
+
+ status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
+ *key, reply);
+
+ if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
+ *dns_auth_error = DNS_RCODE_OK;
+ return status;
+ }
+
+ if (NT_STATUS_IS_OK(status)) {
+
+ status = gensec_session_info(tkey->gensec, tkey,
&tkey->session_info);
+ if (!NT_STATUS_IS_OK(status)) {
+ *dns_auth_error = DNS_RCODE_BADKEY;
+ return status;
+ }
+ *dns_auth_error = DNS_RCODE_OK;
+ }
--
Samba Shared Repository
