--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+
+ endpoint server for the backupkey interface
+
+ Copyright (C) Matthieu Patou <mat@samba.org> 2010
+ Copyright (C) Andreas Schneider <asn@samba.org> 2015
+
+ 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 "rpc_server/dcerpc_server.h"
+#include "librpc/gen_ndr/ndr_backupkey.h"
+#include "dsdb/common/util.h"
+#include "dsdb/samdb/samdb.h"
+#include "lib/ldb/include/ldb_errors.h"
+#include "../lib/util/util_ldb.h"
+#include "param/param.h"
+#include "auth/session.h"
+#include "system/network.h"
+
+#include "../lib/tsocket/tsocket.h"
+#include "../libcli/security/security.h"
+#include "librpc/gen_ndr/ndr_security.h"
+
+#include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
+#include <gnutls/crypto.h>
+#include <gnutls/abstract.h>
+
+static NTSTATUS set_lsa_secret(TALLOC_CTX *mem_ctx,
+ struct ldb_context *ldb,
+ const char *name,
+ const DATA_BLOB *lsa_secret)
+{
+ struct ldb_message *msg;
+ struct ldb_result *res;
+ struct ldb_dn *domain_dn;
+ struct ldb_dn *system_dn;
+ struct ldb_val val;
+ int ret;
+ char *name2;
+ struct timeval now = timeval_current();
+ NTTIME nt_now = timeval_to_nttime(&now);
+ const char *attrs[] = {
+ NULL
+ };
+
+ domain_dn = ldb_get_default_basedn(ldb);
+ if (!domain_dn) {
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ msg = ldb_msg_new(mem_ctx);
+ if (msg == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ /*
+ * This function is a lot like dcesrv_lsa_CreateSecret
+ * in the rpc_server/lsa directory
+ * The reason why we duplicate the effort here is that:
+ * * we want to keep the former function static
+ * * we want to avoid the burden of doing LSA calls
+ * when we can just manipulate the secrets directly
+ * * taillor the function to the particular needs of backup protocol
+ */
+
+ system_dn = samdb_search_dn(ldb, msg, domain_dn, "(&(objectClass=container)(cn=System))");
+ if (system_dn == NULL) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ name2 = talloc_asprintf(msg, "%s Secret", name);
+ if (name2 == NULL) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ ret = ldb_search(ldb, mem_ctx, &res, system_dn, LDB_SCOPE_SUBTREE, attrs,
+ "(&(cn=%s)(objectclass=secret))",
+ ldb_binary_encode_string(mem_ctx, name2));
+
+ if (ret != LDB_SUCCESS || res->count != 0 ) {
+ DEBUG(2, ("Secret %s already exists !\n", name2));
+ talloc_free(msg);
+ return NT_STATUS_OBJECT_NAME_COLLISION;
+ }
+
+ /*
+ * We don't care about previous value as we are
+ * here only if the key didn't exists before
+ */
+
+ msg->dn = ldb_dn_copy(mem_ctx, system_dn);
+ if (msg->dn == NULL) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+ if (!ldb_dn_add_child_fmt(msg->dn, "cn=%s", name2)) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ ret = ldb_msg_add_string(msg, "cn", name2);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+ ret = ldb_msg_add_string(msg, "objectClass", "secret");
+ if (ret != LDB_SUCCESS) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+ ret = samdb_msg_add_uint64(ldb, mem_ctx, msg, "priorSetTime", nt_now);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+ val.data = lsa_secret->data;
+ val.length = lsa_secret->length;
+ ret = ldb_msg_add_value(msg, "currentValue", &val, NULL);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+ ret = samdb_msg_add_uint64(ldb, mem_ctx, msg, "lastSetTime", nt_now);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(msg);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ /*
+ * create the secret with DSDB_MODIFY_RELAX
+ * otherwise dsdb/samdb/ldb_modules/objectclass.c forbid
+ * the create of LSA secret object
+ */
+ ret = dsdb_add(ldb, msg, DSDB_MODIFY_RELAX);
+ if (ret != LDB_SUCCESS) {
+ DEBUG(2,("Failed to create secret record %s: %s\n",
+ ldb_dn_get_linearized(msg->dn),
+ ldb_errstring(ldb)));
+ talloc_free(msg);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ talloc_free(msg);
+ return NT_STATUS_OK;
+}
+
+/* This function is pretty much like dcesrv_lsa_QuerySecret */
+static NTSTATUS get_lsa_secret(TALLOC_CTX *mem_ctx,
+ struct ldb_context *ldb,
+ const char *name,
+ DATA_BLOB *lsa_secret)
+{
+ TALLOC_CTX *tmp_mem;
+ struct ldb_result *res;
+ struct ldb_dn *domain_dn;
+ struct ldb_dn *system_dn;
+ const struct ldb_val *val;
+ uint8_t *data;
+ const char *attrs[] = {
+ "currentValue",
+ NULL
+ };
+ int ret;
+
+ lsa_secret->data = NULL;
+ lsa_secret->length = 0;
+
+ domain_dn = ldb_get_default_basedn(ldb);
+ if (!domain_dn) {
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ tmp_mem = talloc_new(mem_ctx);
+ if (tmp_mem == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ system_dn = samdb_search_dn(ldb, tmp_mem, domain_dn, "(&(objectClass=container)(cn=System))");
+ if (system_dn == NULL) {
+ talloc_free(tmp_mem);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ ret = ldb_search(ldb, mem_ctx, &res, system_dn, LDB_SCOPE_SUBTREE, attrs,
+ "(&(cn=%s Secret)(objectclass=secret))",
+ ldb_binary_encode_string(tmp_mem, name));
+
+ if (ret != LDB_SUCCESS) {
+ talloc_free(tmp_mem);
+ return NT_STATUS_INTERNAL_DB_CORRUPTION;
+ }
+ if (res->count == 0) {
+ talloc_free(tmp_mem);
+ return NT_STATUS_RESOURCE_NAME_NOT_FOUND;
+ }
+ if (res->count > 1) {
+ DEBUG(2, ("Secret %s collision\n", name));
+ talloc_free(tmp_mem);
+ return NT_STATUS_INTERNAL_DB_CORRUPTION;
+ }
+
+ val = ldb_msg_find_ldb_val(res->msgs[0], "currentValue");
+ if (val == NULL) {
+ /*
+ * The secret object is here but we don't have the secret value
+ * The most common case is a RODC
+ */
+ *lsa_secret = data_blob_null;
+ talloc_free(tmp_mem);
+ return NT_STATUS_OK;
+ }
+
+ data = val->data;
+ lsa_secret->data = talloc_move(mem_ctx, &data);
+ lsa_secret->length = val->length;
+
+ talloc_free(tmp_mem);
+ return NT_STATUS_OK;
+}
+
+static int reverse_and_get_bignum(TALLOC_CTX *mem_ctx,
+ DATA_BLOB blob,
+ gnutls_datum_t *datum)
+{
+ uint32_t i;
+
+ datum->data = talloc_array(mem_ctx, uint8_t, blob.length);
+ if (datum->data == NULL) {
+ return -1;
+ }
+
+ for(i = 0; i < blob.length; i++) {
+ datum->data[i] = blob.data[blob.length - i - 1];
+ }
+ datum->size = blob.length;
+
+ return 0;
+}
+
+static NTSTATUS get_pk_from_raw_keypair_params(TALLOC_CTX *ctx,
+ struct bkrp_exported_RSA_key_pair *keypair,
+ gnutls_privkey_t *pk)
+{
+ gnutls_x509_privkey_t x509_privkey = NULL;
+ gnutls_privkey_t privkey = NULL;
+ gnutls_datum_t m, e, d, p, q, u, e1, e2;
+ int rc;
+
+ rc = reverse_and_get_bignum(ctx, keypair->modulus, &m);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ rc = reverse_and_get_bignum(ctx, keypair->public_exponent, &e);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ rc = reverse_and_get_bignum(ctx, keypair->private_exponent, &d);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ rc = reverse_and_get_bignum(ctx, keypair->prime1, &p);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ rc = reverse_and_get_bignum(ctx, keypair->prime2, &q);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ rc = reverse_and_get_bignum(ctx, keypair->coefficient, &u);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ rc = reverse_and_get_bignum(ctx, keypair->exponent1, &e1);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ rc = reverse_and_get_bignum(ctx, keypair->exponent2, &e2);
+ if (rc != 0) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ rc = gnutls_x509_privkey_init(&x509_privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_privkey_init failed - %s\n",
+ gnutls_strerror(rc));
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ rc = gnutls_x509_privkey_import_rsa_raw2(x509_privkey,
+ &m,
+ &e,
+ &d,
+ &p,
+ &q,
+ &u,
+ &e1,
+ &e2);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_privkey_import_rsa_raw2 failed - %s\n",
+ gnutls_strerror(rc));
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ rc = gnutls_privkey_init(&privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_privkey_init failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_privkey_deinit(x509_privkey);
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ rc = gnutls_privkey_import_x509(privkey,
+ x509_privkey,
+ GNUTLS_PRIVKEY_IMPORT_AUTO_RELEASE);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_privkey_import_x509 failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_privkey_deinit(x509_privkey);
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ *pk = privkey;
+
+ return NT_STATUS_OK;
+}
+
+static WERROR get_and_verify_access_check(TALLOC_CTX *sub_ctx,
+ uint32_t version,
+ uint8_t *key_and_iv,
+ uint8_t *access_check,
+ uint32_t access_check_len,
+ struct auth_session_info *session_info)
+{
+ gnutls_cipher_hd_t cipher_handle = { 0 };
+ gnutls_cipher_algorithm_t cipher_algo;
+ DATA_BLOB blob_us;
+ enum ndr_err_code ndr_err;
+ gnutls_datum_t key;
+ gnutls_datum_t iv;
+
+ struct dom_sid *access_sid = NULL;
+ struct dom_sid *caller_sid = NULL;
+ int rc;
+
+ switch (version) {
+ case 2:
+ cipher_algo = GNUTLS_CIPHER_3DES_CBC;
+ break;
+ case 3:
+ cipher_algo = GNUTLS_CIPHER_AES_256_CBC;
+ break;
+ default:
+ return WERR_INVALID_DATA;
+ }
+
+ key.data = key_and_iv;
+ key.size = gnutls_cipher_get_key_size(cipher_algo);
+
+ iv.data = key_and_iv + key.size;
+ iv.size = gnutls_cipher_get_iv_size(cipher_algo);
+
+ /* Allocate data structure for the plaintext */
+ blob_us = data_blob_talloc_zero(sub_ctx, access_check_len);
+ if (blob_us.data == NULL) {
+ return WERR_INVALID_DATA;
+ }
+
+ rc = gnutls_cipher_init(&cipher_handle,
+ cipher_algo,
+ &key,
+ &iv);
+ if (rc < 0) {
+ DBG_ERR("gnutls_cipher_init failed: %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_DATA;
+ }
+
+ rc = gnutls_cipher_decrypt2(cipher_handle,
+ access_check,
+ access_check_len,
+ blob_us.data,
+ blob_us.length);
+ gnutls_cipher_deinit(cipher_handle);
+ if (rc < 0) {
+ DBG_ERR("gnutls_cipher_decrypt2 failed: %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_DATA;
+ }
+
+ switch (version) {
+ case 2:
+ {
+ uint32_t hash_size = 20;
+ uint8_t hash[hash_size];
+ gnutls_hash_hd_t dig_ctx;
+ struct bkrp_access_check_v2 uncrypted_accesscheckv2;
+
+ ndr_err = ndr_pull_struct_blob(&blob_us, sub_ctx, &uncrypted_accesscheckv2,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_access_check_v2);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ /* Unable to unmarshall */
+ return WERR_INVALID_DATA;
+ }
+ if (uncrypted_accesscheckv2.magic != 0x1) {
+ /* wrong magic */
+ return WERR_INVALID_DATA;
+ }
+
+ gnutls_hash_init(&dig_ctx, GNUTLS_DIG_SHA1);
+ gnutls_hash(dig_ctx,
+ blob_us.data,
+ blob_us.length - hash_size);
+ gnutls_hash_deinit(dig_ctx, hash);
+ /*
+ * We free it after the sha1 calculation because blob.data
+ * point to the same area
+ */
+
+ if (memcmp(hash, uncrypted_accesscheckv2.hash, hash_size) != 0) {
+ DEBUG(2, ("Wrong hash value in the access check in backup key remote protocol\n"));
+ return WERR_INVALID_DATA;
+ }
+ access_sid = &(uncrypted_accesscheckv2.sid);
+ break;
+ }
+ case 3:
+ {
+ uint32_t hash_size = 64;
+ uint8_t hash[hash_size];
+ gnutls_hash_hd_t dig_ctx;
+ struct bkrp_access_check_v3 uncrypted_accesscheckv3;
+
+ ndr_err = ndr_pull_struct_blob(&blob_us, sub_ctx, &uncrypted_accesscheckv3,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_access_check_v3);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ /* Unable to unmarshall */
+ return WERR_INVALID_DATA;
+ }
+ if (uncrypted_accesscheckv3.magic != 0x1) {
+ /* wrong magic */
+ return WERR_INVALID_DATA;
+ }
+
+ gnutls_hash_init(&dig_ctx, GNUTLS_DIG_SHA512);
+ gnutls_hash(dig_ctx,
+ blob_us.data,
+ blob_us.length - hash_size);
+ gnutls_hash_deinit(dig_ctx, hash);
+
+ /*
+ * We free it after the sha1 calculation because blob.data
+ * point to the same area
+ */
+
+ if (memcmp(hash, uncrypted_accesscheckv3.hash, hash_size) != 0) {
+ DEBUG(2, ("Wrong hash value in the access check in backup key remote protocol\n"));
+ return WERR_INVALID_DATA;
+ }
+ access_sid = &(uncrypted_accesscheckv3.sid);
+ break;
+ }
+ default:
+ /* Never reached normally as we filtered at the switch / case level */
+ return WERR_INVALID_DATA;
+ }
+
+ caller_sid = &session_info->security_token->sids[PRIMARY_USER_SID_INDEX];
+
+ if (!dom_sid_equal(caller_sid, access_sid)) {
+ return WERR_INVALID_ACCESS;
+ }
+ return WERR_OK;
+}
+
+/*
+ * We have some data, such as saved website or IMAP passwords that the
+ * client has in profile on-disk. This needs to be decrypted. This
+ * version gives the server the data over the network (protected by
+ * the X.509 certificate and public key encryption, and asks that it
+ * be decrypted returned for short-term use, protected only by the
+ * negotiated transport encryption.
+ *
+ * The data is NOT stored in the LSA, but a X.509 certificate, public
+ * and private keys used to encrypt the data will be stored. There is
+ * only one active encryption key pair and certificate per domain, it
+ * is pointed at with G$BCKUPKEY_PREFERRED in the LSA secrets store.
+ *
+ * The potentially multiple valid decrypting key pairs are in turn
+ * stored in the LSA secrets store as G$BCKUPKEY_keyGuidString.
+ *
+ */
+static WERROR bkrp_client_wrap_decrypt_data(struct dcesrv_call_state *dce_call,
+ TALLOC_CTX *mem_ctx,
+ struct bkrp_BackupKey *r,
+ struct ldb_context *ldb_ctx)
+{
+ struct bkrp_client_side_wrapped uncrypt_request;
+ DATA_BLOB blob;
+ enum ndr_err_code ndr_err;
+ char *guid_string;
+ char *cert_secret_name;
+ DATA_BLOB lsa_secret;
+ DATA_BLOB *uncrypted_data = NULL;
+ NTSTATUS status;
+ uint32_t requested_version;
+
+ blob.data = r->in.data_in;
+ blob.length = r->in.data_in_len;
+
+ if (r->in.data_in_len < 4 || r->in.data_in == NULL) {
+ return WERR_INVALID_PARAM;
+ }
+
+ /*
+ * We check for the version here, so we can actually print the
+ * message as we are unlikely to parse it with NDR.
+ */
+ requested_version = IVAL(r->in.data_in, 0);
+ if ((requested_version != BACKUPKEY_CLIENT_WRAP_VERSION2)
+ && (requested_version != BACKUPKEY_CLIENT_WRAP_VERSION3)) {
+ DEBUG(1, ("Request for unknown BackupKey sub-protocol %d\n", requested_version));
+ return WERR_INVALID_PARAMETER;
+ }
+
+ ndr_err = ndr_pull_struct_blob(&blob, mem_ctx, &uncrypt_request,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_client_side_wrapped);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INVALID_PARAM;
+ }
+
+ if ((uncrypt_request.version != BACKUPKEY_CLIENT_WRAP_VERSION2)
+ && (uncrypt_request.version != BACKUPKEY_CLIENT_WRAP_VERSION3)) {
+ DEBUG(1, ("Request for unknown BackupKey sub-protocol %d\n", uncrypt_request.version));
+ return WERR_INVALID_PARAMETER;
+ }
+
+ guid_string = GUID_string(mem_ctx, &uncrypt_request.guid);
+ if (guid_string == NULL) {
+ return WERR_NOMEM;
+ }
+
+ cert_secret_name = talloc_asprintf(mem_ctx,
+ "BCKUPKEY_%s",
+ guid_string);
+ if (cert_secret_name == NULL) {
+ return WERR_NOMEM;
+ }
+
+ status = get_lsa_secret(mem_ctx,
+ ldb_ctx,
+ cert_secret_name,
+ &lsa_secret);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(10, ("Error while fetching secret %s\n", cert_secret_name));
+ return WERR_INVALID_DATA;
+ } else if (lsa_secret.length == 0) {
+ /* we do not have the real secret attribute, like if we are an RODC */
+ return WERR_INVALID_PARAMETER;
+ } else {
+ struct bkrp_exported_RSA_key_pair keypair;
+ gnutls_privkey_t privkey = NULL;
+ gnutls_datum_t reversed_secret;
+ gnutls_datum_t uncrypted_secret;
+ uint32_t i;
+ DATA_BLOB blob_us;
+ WERROR werr;
+ int rc;
+
+ ndr_err = ndr_pull_struct_blob(&lsa_secret, mem_ctx, &keypair, (ndr_pull_flags_fn_t)ndr_pull_bkrp_exported_RSA_key_pair);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ DEBUG(2, ("Unable to parse the ndr encoded cert in key %s\n", cert_secret_name));
+ return WERR_FILE_NOT_FOUND;
+ }
+
+ status = get_pk_from_raw_keypair_params(mem_ctx,
+ &keypair,
+ &privkey);
+ if (!NT_STATUS_IS_OK(status)) {
+ return WERR_INTERNAL_ERROR;
+ }
+
+ reversed_secret.data = talloc_array(mem_ctx, uint8_t,
+ uncrypt_request.encrypted_secret_len);
+ if (reversed_secret.data == NULL) {
+ gnutls_privkey_deinit(privkey);
+ return WERR_NOMEM;
+ }
+
+ /* The secret has to be reversed ... */
+ for(i=0; i< uncrypt_request.encrypted_secret_len; i++) {
+ uint8_t *reversed = (uint8_t *)reversed_secret.data;
+ uint8_t *uncrypt = uncrypt_request.encrypted_secret;
+ reversed[i] = uncrypt[uncrypt_request.encrypted_secret_len - 1 - i];
+ }
+ reversed_secret.size = uncrypt_request.encrypted_secret_len;
+
+ /*
+ * Let's try to decrypt the secret now that
+ * we have the private key ...
+ */
+ rc = gnutls_privkey_decrypt_data(privkey,
+ 0,
+ &reversed_secret,
+ &uncrypted_secret);
+ gnutls_privkey_deinit(privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ /* We are not able to decrypt the secret, looks like something is wrong */
+ return WERR_INVALID_PARAMETER;
+ }
+ blob_us.data = uncrypted_secret.data;
+ blob_us.length = uncrypted_secret.size;
+
+ if (uncrypt_request.version == 2) {
+ struct bkrp_encrypted_secret_v2 uncrypted_secretv2;
+
+ ndr_err = ndr_pull_struct_blob(&blob_us, mem_ctx, &uncrypted_secretv2,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_encrypted_secret_v2);
+ gnutls_free(uncrypted_secret.data);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ /* Unable to unmarshall */
+ return WERR_INVALID_DATA;
+ }
+ if (uncrypted_secretv2.magic != 0x20) {
+ /* wrong magic */
+ return WERR_INVALID_DATA;
+ }
+
+ werr = get_and_verify_access_check(mem_ctx, 2,
+ uncrypted_secretv2.payload_key,
+ uncrypt_request.access_check,
+ uncrypt_request.access_check_len,
+ dce_call->conn->auth_state.session_info);
+ if (!W_ERROR_IS_OK(werr)) {
+ return werr;
+ }
+ uncrypted_data = talloc(mem_ctx, DATA_BLOB);
+ if (uncrypted_data == NULL) {
+ return WERR_INVALID_DATA;
+ }
+
+ uncrypted_data->data = uncrypted_secretv2.secret;
+ uncrypted_data->length = uncrypted_secretv2.secret_len;
+ }
+ if (uncrypt_request.version == 3) {
+ struct bkrp_encrypted_secret_v3 uncrypted_secretv3;
+
+ ndr_err = ndr_pull_struct_blob(&blob_us, mem_ctx, &uncrypted_secretv3,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_encrypted_secret_v3);
+ gnutls_free(uncrypted_secret.data);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ /* Unable to unmarshall */
+ return WERR_INVALID_DATA;
+ }
+
+ if (uncrypted_secretv3.magic1 != 0x30 ||
+ uncrypted_secretv3.magic2 != 0x6610 ||
+ uncrypted_secretv3.magic3 != 0x800e) {
+ /* wrong magic */
+ return WERR_INVALID_DATA;
+ }
+
+ /*
+ * Confirm that the caller is permitted to
+ * read this particular data. Because one key
+ * pair is used per domain, the caller could
+ * have stolen the profile data on-disk and
+ * would otherwise be able to read the
+ * passwords.
+ */
+
+ werr = get_and_verify_access_check(mem_ctx, 3,
+ uncrypted_secretv3.payload_key,
+ uncrypt_request.access_check,
+ uncrypt_request.access_check_len,
+ dce_call->conn->auth_state.session_info);
+ if (!W_ERROR_IS_OK(werr)) {
+ return werr;
+ }
+
+ uncrypted_data = talloc(mem_ctx, DATA_BLOB);
+ if (uncrypted_data == NULL) {
+ return WERR_INVALID_DATA;
+ }
+
+ uncrypted_data->data = uncrypted_secretv3.secret;
+ uncrypted_data->length = uncrypted_secretv3.secret_len;
+ }
+
+ /*
+ * Yeah if we are here all looks pretty good:
+ * - hash is ok
+ * - user sid is the same as the one in access check
+ * - we were able to decrypt the whole stuff
+ */
+ }
+
+ if (uncrypted_data->data == NULL) {
+ return WERR_INVALID_DATA;
+ }
+
+ /* There is a magic value a the beginning of the data
+ * we can use an adhoc structure but as the
+ * parent structure is just an array of bytes it a lot of work
+ * work just prepending 4 bytes
+ */
+ *(r->out.data_out) = talloc_zero_array(mem_ctx, uint8_t, uncrypted_data->length + 4);
+ W_ERROR_HAVE_NO_MEMORY(*(r->out.data_out));
+ memcpy(4+*(r->out.data_out), uncrypted_data->data, uncrypted_data->length);
+ *(r->out.data_out_len) = uncrypted_data->length + 4;
+
+ return WERR_OK;
+}
+
+static DATA_BLOB *reverse_and_get_blob(TALLOC_CTX *mem_ctx,
+ gnutls_datum_t *datum)
+{
+ DATA_BLOB *blob;
+ size_t i;
+
+ blob = talloc(mem_ctx, DATA_BLOB);
+ if (blob == NULL) {
+ return NULL;
+ }
+
+ blob->length = datum->size;
+ if (datum->data[0] == '\0') {
+ /* The datum has a leading byte zero, skip it */
+ blob->length = datum->size - 1;
+ }
+ blob->data = talloc_zero_array(mem_ctx, uint8_t, blob->length);
+ if (blob->data == NULL) {
+ talloc_free(blob);
+ return NULL;
+ }
+
+ for (i = 0; i < blob->length; i++) {
+ blob->data[i] = datum->data[datum->size - i - 1];
+ }
+
+ return blob;
+}
+
+static WERROR create_privkey_rsa(gnutls_privkey_t *pk)
+{
+ int bits = 2048;
+ gnutls_x509_privkey_t x509_privkey = NULL;
+ gnutls_privkey_t privkey = NULL;
+ int rc;
+
+ rc = gnutls_x509_privkey_init(&x509_privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_privkey_init failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_INTERNAL_ERROR;
+ }
+
+ rc = gnutls_x509_privkey_generate(x509_privkey,
+ GNUTLS_PK_RSA,
+ bits,
+ 0);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_privkey_generate failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_privkey_deinit(x509_privkey);
+ return WERR_INTERNAL_ERROR;
+ }
+
+ rc = gnutls_privkey_init(&privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_privkey_init failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_privkey_deinit(x509_privkey);
+ return WERR_INTERNAL_ERROR;
+ }
+
+ rc = gnutls_privkey_import_x509(privkey,
+ x509_privkey,
+ GNUTLS_PRIVKEY_IMPORT_AUTO_RELEASE);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_privkey_import_x509 failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_privkey_deinit(x509_privkey);
+ return WERR_INTERNAL_ERROR;
+ }
+
+ *pk = privkey;
+
+ return WERR_OK;
+}
+
+static WERROR self_sign_cert(TALLOC_CTX *mem_ctx,
+ time_t lifetime,
+ const char *dn,
+ gnutls_privkey_t issuer_privkey,
+ gnutls_x509_crt_t *certificate,
+ DATA_BLOB *guidblob)
+{
+ gnutls_datum_t unique_id;
+ gnutls_datum_t serial_number;
+ gnutls_x509_crt_t issuer_cert;
+ gnutls_x509_privkey_t x509_issuer_privkey;
+ time_t activation = time(NULL);
+ time_t expiry = activation + lifetime;
+ const char *error_string;
+ uint8_t *reversed;
+ size_t i;
+ int rc;
+
+ unique_id.size = guidblob->length;
+ unique_id.data = talloc_memdup(mem_ctx,
+ guidblob->data,
+ guidblob->length);
+ if (unique_id.data == NULL) {
+ return WERR_NOMEM;
+ }
+
+ reversed = talloc_array(mem_ctx, uint8_t, guidblob->length);
+ if (reversed == NULL) {
+ talloc_free(unique_id.data);
+ return WERR_NOMEM;
+ }
+
+ /* Native AD generates certificates with serialnumber in reversed notation */
+ for (i = 0; i < guidblob->length; i++) {
+ uint8_t *uncrypt = guidblob->data;
+ reversed[i] = uncrypt[guidblob->length - i - 1];
+ }
+ serial_number.size = guidblob->length;
+ serial_number.data = reversed;
+
+ /* Create certificate to sign */
+ rc = gnutls_x509_crt_init(&issuer_cert);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_init failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_NOMEM;
+ }
+
+ rc = gnutls_x509_crt_set_dn(issuer_cert, dn, &error_string);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_dn failed - %s (%s)\n",
+ gnutls_strerror(rc),
+ error_string);
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_issuer_dn(issuer_cert, dn, &error_string);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_issuer_dn failed - %s (%s)\n",
+ gnutls_strerror(rc),
+ error_string);
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ /* Get x509 privkey for subjectPublicKeyInfo */
+ rc = gnutls_x509_privkey_init(&x509_issuer_privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_privkey_init failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_privkey_export_x509(issuer_privkey,
+ &x509_issuer_privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_privkey_init failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_privkey_deinit(x509_issuer_privkey);
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ /* Set subjectPublicKeyInfo */
+ rc = gnutls_x509_crt_set_key(issuer_cert, x509_issuer_privkey);
+ gnutls_x509_privkey_deinit(x509_issuer_privkey);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_pubkey failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_activation_time(issuer_cert, activation);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_activation_time failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_expiration_time(issuer_cert, expiry);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_expiration_time failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_version(issuer_cert, 3);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_version failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_subject_unique_id(issuer_cert,
+ unique_id.data,
+ unique_id.size);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_subject_key_id failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_issuer_unique_id(issuer_cert,
+ unique_id.data,
+ unique_id.size);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_issuer_unique_id failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_set_serial(issuer_cert,
+ serial_number.data,
+ serial_number.size);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_set_serial failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_x509_crt_deinit(issuer_cert);
+ return WERR_INVALID_PARAM;
+ }
+
+ rc = gnutls_x509_crt_privkey_sign(issuer_cert,
+ issuer_cert,
+ issuer_privkey,
+ GNUTLS_DIG_SHA1,
+ 0);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_privkey_sign failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_PARAM;
+ }
+
+ *certificate = issuer_cert;
+
+ return WERR_OK;
+}
+
+/* Return an error when we fail to generate a certificate */
+static WERROR generate_bkrp_cert(TALLOC_CTX *mem_ctx,
+ struct dcesrv_call_state *dce_call,
+ struct ldb_context *ldb_ctx,
+ const char *dn)
+{
+ WERROR werr;
+ gnutls_privkey_t issuer_privkey = NULL;
+ gnutls_x509_crt_t cert = NULL;
+ gnutls_datum_t cert_blob;
+ gnutls_datum_t m, e, d, p, q, u, e1, e2;
+ DATA_BLOB blob;
+ DATA_BLOB blobkeypair;
+ DATA_BLOB *tmp;
+ bool ok = true;
+ struct GUID guid = GUID_random();
+ NTSTATUS status;
+ char *secret_name;
+ struct bkrp_exported_RSA_key_pair keypair;
+ enum ndr_err_code ndr_err;
+ time_t nb_seconds_validity = 3600 * 24 * 365;
+ int rc;
+
+ DEBUG(6, ("Trying to generate a certificate\n"));
+ werr = create_privkey_rsa(&issuer_privkey);
+ if (!W_ERROR_IS_OK(werr)) {
+ return werr;
+ }
+
+ status = GUID_to_ndr_blob(&guid, mem_ctx, &blob);
+ if (!NT_STATUS_IS_OK(status)) {
+ gnutls_privkey_deinit(issuer_privkey);
+ return WERR_INVALID_DATA;
+ }
+
+ werr = self_sign_cert(mem_ctx,
+ nb_seconds_validity,
+ dn,
+ issuer_privkey,
+ &cert,
+ &blob);
+ if (!W_ERROR_IS_OK(werr)) {
+ gnutls_privkey_deinit(issuer_privkey);
+ return WERR_INVALID_DATA;
+ }
+
+ rc = gnutls_x509_crt_export2(cert, GNUTLS_X509_FMT_DER, &cert_blob);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_x509_crt_export2 failed - %s\n",
+ gnutls_strerror(rc));
+ gnutls_privkey_deinit(issuer_privkey);
+ gnutls_x509_crt_deinit(cert);
+ return WERR_INVALID_DATA;
+ }
+
+ keypair.cert.length = cert_blob.size;
+ keypair.cert.data = talloc_memdup(mem_ctx, cert_blob.data, cert_blob.size);
+ gnutls_x509_crt_deinit(cert);
+ gnutls_free(cert_blob.data);
+ if (keypair.cert.data == NULL) {
+ gnutls_privkey_deinit(issuer_privkey);
+ return WERR_NOMEM;
+ }
+
+ rc = gnutls_privkey_export_rsa_raw(issuer_privkey,
+ &m,
+ &e,
+ &d,
+ &p,
+ &q,
+ &u,
+ &e1,
+ &e2);
+ if (rc != GNUTLS_E_SUCCESS) {
+ gnutls_privkey_deinit(issuer_privkey);
+ return WERR_INVALID_DATA;
+ }
+
+ /*
+ * Heimdal's bignum are big endian and the
+ * structure expect it to be in little endian
+ * so we reverse the buffer to make it work
+ */
+ tmp = reverse_and_get_blob(mem_ctx, &e);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ SMB_ASSERT(tmp->length <= 4);
+ keypair.public_exponent = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &d);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.private_exponent = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &m);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.modulus = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &p);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.prime1 = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &q);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.prime2 = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &e1);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.exponent1 = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &e2);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.exponent2 = *tmp;
+ }
+
+ tmp = reverse_and_get_blob(mem_ctx, &u);
+ if (tmp == NULL) {
+ ok = false;
+ } else {
+ keypair.coefficient = *tmp;
+ }
+
+ /* One of the keypair allocation was wrong */
+ if (ok == false) {
+ gnutls_privkey_deinit(issuer_privkey);
+ return WERR_INVALID_DATA;
+ }
+
+ keypair.certificate_len = keypair.cert.length;
+ ndr_err = ndr_push_struct_blob(&blobkeypair,
+ mem_ctx,
+ &keypair,
+ (ndr_push_flags_fn_t)ndr_push_bkrp_exported_RSA_key_pair);
+ gnutls_privkey_deinit(issuer_privkey);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INVALID_DATA;
+ }
+
+ secret_name = talloc_asprintf(mem_ctx, "BCKUPKEY_%s", GUID_string(mem_ctx, &guid));
+ if (secret_name == NULL) {
+ return WERR_OUTOFMEMORY;
+ }
+
+ status = set_lsa_secret(mem_ctx, ldb_ctx, secret_name, &blobkeypair);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to save the secret %s\n", secret_name));
+ }
+ talloc_free(secret_name);
+
+ GUID_to_ndr_blob(&guid, mem_ctx, &blob);
+ status = set_lsa_secret(mem_ctx, ldb_ctx, "BCKUPKEY_PREFERRED", &blob);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to save the secret BCKUPKEY_PREFERRED\n"));
+ }
+
+ return WERR_OK;
+}
+
+static WERROR bkrp_retrieve_client_wrap_key(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+ struct bkrp_BackupKey *r, struct ldb_context *ldb_ctx)
+{
+ struct GUID guid;
+ char *guid_string;
+ DATA_BLOB lsa_secret;
+ enum ndr_err_code ndr_err;
+ NTSTATUS status;
+
+ /*
+ * here we basicaly need to return our certificate
+ * search for lsa secret BCKUPKEY_PREFERRED first
+ */
+
+ status = get_lsa_secret(mem_ctx,
+ ldb_ctx,
+ "BCKUPKEY_PREFERRED",
+ &lsa_secret);
+ if (NT_STATUS_EQUAL(status, NT_STATUS_RESOURCE_NAME_NOT_FOUND)) {
+ /* Ok we can be in this case if there was no certs */
+ struct loadparm_context *lp_ctx = dce_call->conn->dce_ctx->lp_ctx;
+ char *dn = talloc_asprintf(mem_ctx, "CN=%s",
+ lpcfg_realm(lp_ctx));
+
+ WERROR werr = generate_bkrp_cert(mem_ctx, dce_call, ldb_ctx, dn);
+ if (!W_ERROR_IS_OK(werr)) {
+ return WERR_INVALID_PARAMETER;
+ }
+ status = get_lsa_secret(mem_ctx,
+ ldb_ctx,
+ "BCKUPKEY_PREFERRED",
+ &lsa_secret);
+
+ if (!NT_STATUS_IS_OK(status)) {
+ /* Ok we really don't manage to get this certs ...*/
+ DEBUG(2, ("Unable to locate BCKUPKEY_PREFERRED after cert generation\n"));
+ return WERR_FILE_NOT_FOUND;
+ }
+ } else if (!NT_STATUS_IS_OK(status)) {
+ return WERR_INTERNAL_ERROR;
+ }
+
+ if (lsa_secret.length == 0) {
+ DEBUG(1, ("No secret in BCKUPKEY_PREFERRED, are we an undetected RODC?\n"));
+ return WERR_INTERNAL_ERROR;
+ } else {
+ char *cert_secret_name;
+
+ status = GUID_from_ndr_blob(&lsa_secret, &guid);
+ if (!NT_STATUS_IS_OK(status)) {
+ return WERR_FILE_NOT_FOUND;
+ }
+
+ guid_string = GUID_string(mem_ctx, &guid);
+ if (guid_string == NULL) {
+ /* We return file not found because the client
+ * expect this error
+ */
+ return WERR_FILE_NOT_FOUND;
+ }
+
+ cert_secret_name = talloc_asprintf(mem_ctx,
+ "BCKUPKEY_%s",
+ guid_string);
+ status = get_lsa_secret(mem_ctx,
+ ldb_ctx,
+ cert_secret_name,
+ &lsa_secret);
+ if (!NT_STATUS_IS_OK(status)) {
+ return WERR_FILE_NOT_FOUND;
+ }
+
+ if (lsa_secret.length != 0) {
+ struct bkrp_exported_RSA_key_pair keypair;
+ ndr_err = ndr_pull_struct_blob(&lsa_secret, mem_ctx, &keypair,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_exported_RSA_key_pair);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_FILE_NOT_FOUND;
+ }
+ *(r->out.data_out_len) = keypair.cert.length;
+ *(r->out.data_out) = talloc_memdup(mem_ctx, keypair.cert.data, keypair.cert.length);
+ W_ERROR_HAVE_NO_MEMORY(*(r->out.data_out));
+ return WERR_OK;
+ } else {
+ DEBUG(1, ("No or broken secret called %s\n", cert_secret_name));
+ return WERR_INTERNAL_ERROR;
+ }
+ }
+
+ return WERR_NOT_SUPPORTED;
+}
+
+static WERROR generate_bkrp_server_wrap_key(TALLOC_CTX *ctx, struct ldb_context *ldb_ctx)
+{
+ struct GUID guid = GUID_random();
+ enum ndr_err_code ndr_err;
+ DATA_BLOB blob_wrap_key, guid_blob;
+ struct bkrp_dc_serverwrap_key wrap_key;
+ NTSTATUS status;
+ char *secret_name;
+ TALLOC_CTX *frame = talloc_stackframe();
+
+ generate_random_buffer(wrap_key.key, sizeof(wrap_key.key));
+
+ ndr_err = ndr_push_struct_blob(&blob_wrap_key, ctx, &wrap_key, (ndr_push_flags_fn_t)ndr_push_bkrp_dc_serverwrap_key);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ TALLOC_FREE(frame);
+ return WERR_INVALID_DATA;
+ }
+
+ secret_name = talloc_asprintf(frame, "BCKUPKEY_%s", GUID_string(ctx, &guid));
+ if (secret_name == NULL) {
+ TALLOC_FREE(frame);
+ return WERR_NOMEM;
+ }
+
+ status = set_lsa_secret(frame, ldb_ctx, secret_name, &blob_wrap_key);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to save the secret %s\n", secret_name));
+ TALLOC_FREE(frame);
+ return WERR_INTERNAL_ERROR;
+ }
+
+ status = GUID_to_ndr_blob(&guid, frame, &guid_blob);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to save the secret %s\n", secret_name));
+ TALLOC_FREE(frame);
+ }
+
+ status = set_lsa_secret(frame, ldb_ctx, "BCKUPKEY_P", &guid_blob);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to save the secret %s\n", secret_name));
+ TALLOC_FREE(frame);
+ return WERR_INTERNAL_ERROR;
+ }
+
+ TALLOC_FREE(frame);
+
+ return WERR_OK;
+}
+
+/*
+ * Find the specified decryption keys from the LSA secrets store as
+ * G$BCKUPKEY_keyGuidString.
+ */
+
+static WERROR bkrp_do_retrieve_server_wrap_key(TALLOC_CTX *mem_ctx, struct ldb_context *ldb_ctx,
+ struct bkrp_dc_serverwrap_key *server_key,
+ struct GUID *guid)
+{
+ NTSTATUS status;
+ DATA_BLOB lsa_secret;
+ char *secret_name;
+ char *guid_string;
+ enum ndr_err_code ndr_err;
+
+ guid_string = GUID_string(mem_ctx, guid);
+ if (guid_string == NULL) {
+ /* We return file not found because the client
+ * expect this error
+ */
+ return WERR_FILE_NOT_FOUND;
+ }
+
+ secret_name = talloc_asprintf(mem_ctx, "BCKUPKEY_%s", guid_string);
+ if (secret_name == NULL) {
+ return WERR_NOMEM;
+ }
+
+ status = get_lsa_secret(mem_ctx, ldb_ctx, secret_name, &lsa_secret);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(10, ("Error while fetching secret %s\n", secret_name));
+ return WERR_INVALID_DATA;
+ }
+ if (lsa_secret.length == 0) {
+ /* RODC case, we do not have secrets locally */
+ DEBUG(1, ("Unable to fetch value for secret %s, are we an undetected RODC?\n",
+ secret_name));
+ return WERR_INTERNAL_ERROR;
+ }
+ ndr_err = ndr_pull_struct_blob(&lsa_secret, mem_ctx, server_key,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_dc_serverwrap_key);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ DEBUG(2, ("Unable to parse the ndr encoded server wrap key %s\n", secret_name));
+ return WERR_INVALID_DATA;
+ }
+
+ return WERR_OK;
+}
+
+/*
+ * Find the current, preferred ServerWrap Key by looking at
+ * G$BCKUPKEY_P in the LSA secrets store.
+ *
+ * Then find the current decryption keys from the LSA secrets store as
+ * G$BCKUPKEY_keyGuidString.
+ */
+
+static WERROR bkrp_do_retrieve_default_server_wrap_key(TALLOC_CTX *mem_ctx,
+ struct ldb_context *ldb_ctx,
+ struct bkrp_dc_serverwrap_key *server_key,
+ struct GUID *returned_guid)
+{
+ NTSTATUS status;
+ DATA_BLOB guid_binary;
+
+ status = get_lsa_secret(mem_ctx, ldb_ctx, "BCKUPKEY_P", &guid_binary);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(10, ("Error while fetching secret BCKUPKEY_P to find current GUID\n"));
+ return WERR_FILE_NOT_FOUND;
+ } else if (guid_binary.length == 0) {
+ /* RODC case, we do not have secrets locally */
+ DEBUG(1, ("Unable to fetch value for secret BCKUPKEY_P, are we an undetected RODC?\n"));
+ return WERR_INTERNAL_ERROR;
+ }
+
+ status = GUID_from_ndr_blob(&guid_binary, returned_guid);
+ if (!NT_STATUS_IS_OK(status)) {
+ return WERR_FILE_NOT_FOUND;
+ }
+
+ return bkrp_do_retrieve_server_wrap_key(mem_ctx, ldb_ctx,
+ server_key, returned_guid);
+}
+
+static WERROR bkrp_server_wrap_decrypt_data(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+ struct bkrp_BackupKey *r ,struct ldb_context *ldb_ctx)
+{
+ WERROR werr;
+ struct bkrp_server_side_wrapped decrypt_request;
+ DATA_BLOB sid_blob, encrypted_blob;
+ DATA_BLOB blob;
+ enum ndr_err_code ndr_err;
+ struct bkrp_dc_serverwrap_key server_key;
+ struct bkrp_rc4encryptedpayload rc4payload;
+ struct dom_sid *caller_sid;
+ uint8_t symkey[20]; /* SHA-1 hash len */
+ uint8_t mackey[20]; /* SHA-1 hash len */
+ uint8_t mac[20]; /* SHA-1 hash len */
+ gnutls_hmac_hd_t hmac_hnd;
+ gnutls_cipher_hd_t cipher_hnd;
+ gnutls_datum_t cipher_key;
+ int rc;
+
+ blob.data = r->in.data_in;
+ blob.length = r->in.data_in_len;
+
+ if (r->in.data_in_len == 0 || r->in.data_in == NULL) {
+ return WERR_INVALID_PARAM;
+ }
+
+ ndr_err = ndr_pull_struct_blob_all(&blob, mem_ctx, &decrypt_request,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_server_side_wrapped);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INVALID_PARAM;
+ }
+
+ if (decrypt_request.magic != BACKUPKEY_SERVER_WRAP_VERSION) {
+ return WERR_INVALID_PARAM;
+ }
+
+ werr = bkrp_do_retrieve_server_wrap_key(mem_ctx, ldb_ctx, &server_key,
+ &decrypt_request.guid);
+ if (!W_ERROR_IS_OK(werr)) {
+ return werr;
+ }
+
+ dump_data_pw("server_key: \n", server_key.key, sizeof(server_key.key));
+
+ dump_data_pw("r2: \n", decrypt_request.r2, sizeof(decrypt_request.r2));
+
+ /*
+ * This is *not* the leading 64 bytes, as indicated in MS-BKRP 3.1.4.1.1
+ * BACKUPKEY_BACKUP_GUID, it really is the whole key
+ */
+
+ gnutls_hmac_init(&hmac_hnd,
+ GNUTLS_MAC_SHA1,
+ server_key.key,
+ sizeof(server_key.key));
+ gnutls_hmac(hmac_hnd,
+ decrypt_request.r2,
+ sizeof(decrypt_request.r2));
+ gnutls_hmac_output(hmac_hnd, symkey);
+
+ dump_data_pw("symkey: \n", symkey, sizeof(symkey));
+
+ /* rc4 decrypt sid and secret using sym key */
+ cipher_key.data = symkey;
+ cipher_key.size = sizeof(symkey);
+
+ encrypted_blob = data_blob_const(decrypt_request.rc4encryptedpayload,
+ decrypt_request.ciphertext_length);
+
+ rc = gnutls_cipher_init(&cipher_hnd,
+ GNUTLS_CIPHER_ARCFOUR_128,
+ &cipher_key,
+ NULL);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_cipher_init failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_PARAM;
+ }
+ rc = gnutls_cipher_encrypt2(cipher_hnd,
+ encrypted_blob.data,
+ encrypted_blob.length,
+ encrypted_blob.data,
+ encrypted_blob.length);
+ gnutls_cipher_deinit(cipher_hnd);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_cipher_encrypt2 failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_PARAM;
+ }
+
+ ndr_err = ndr_pull_struct_blob_all(&encrypted_blob, mem_ctx, &rc4payload,
+ (ndr_pull_flags_fn_t)ndr_pull_bkrp_rc4encryptedpayload);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INVALID_PARAM;
+ }
+
+ if (decrypt_request.payload_length != rc4payload.secret_data.length) {
+ return WERR_INVALID_PARAM;
+ }
+
+ dump_data_pw("r3: \n", rc4payload.r3, sizeof(rc4payload.r3));
+
+ /*
+ * This is *not* the leading 64 bytes, as indicated in MS-BKRP 3.1.4.1.1
+ * BACKUPKEY_BACKUP_GUID, it really is the whole key
+ */
+ gnutls_hmac(hmac_hnd,
+ rc4payload.r3,
+ sizeof(rc4payload.r3));
+ gnutls_hmac_deinit(hmac_hnd, mackey);
+
+ dump_data_pw("mackey: \n", mackey, sizeof(mackey));
+
+ ndr_err = ndr_push_struct_blob(&sid_blob, mem_ctx, &rc4payload.sid,
+ (ndr_push_flags_fn_t)ndr_push_dom_sid);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INTERNAL_ERROR;
+ }
+
+ gnutls_hmac_init(&hmac_hnd,
+ GNUTLS_MAC_SHA1,
+ mackey,
+ sizeof(mackey));
+ /* SID field */
+ gnutls_hmac(hmac_hnd,
+ sid_blob.data,
+ sid_blob.length);
+ /* Secret field */
+ gnutls_hmac(hmac_hnd,
+ rc4payload.secret_data.data,
+ rc4payload.secret_data.length);
+ gnutls_hmac_deinit(hmac_hnd, mac);
+
+ dump_data_pw("mac: \n", mac, sizeof(mac));
+ dump_data_pw("rc4payload.mac: \n", rc4payload.mac, sizeof(rc4payload.mac));
+
+ if (memcmp(mac, rc4payload.mac, sizeof(mac)) != 0) {
+ return WERR_INVALID_ACCESS;
+ }
+
+ caller_sid = &dce_call->conn->auth_state.session_info->security_token->sids[PRIMARY_USER_SID_INDEX];
+
+ if (!dom_sid_equal(&rc4payload.sid, caller_sid)) {
+ return WERR_INVALID_ACCESS;
+ }
+
+ *(r->out.data_out) = rc4payload.secret_data.data;
+ *(r->out.data_out_len) = rc4payload.secret_data.length;
+
+ return WERR_OK;
+}
+
+/*
+ * For BACKUPKEY_RESTORE_GUID we need to check the first 4 bytes to
+ * determine what type of restore is wanted.
+ *
+ * See MS-BKRP 3.1.4.1.4 BACKUPKEY_RESTORE_GUID point 1.
+ */
+
+static WERROR bkrp_generic_decrypt_data(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+ struct bkrp_BackupKey *r, struct ldb_context *ldb_ctx)
+{
+ if (r->in.data_in_len < 4 || r->in.data_in == NULL) {
+ return WERR_INVALID_PARAM;
+ }
+
+ if (IVAL(r->in.data_in, 0) == BACKUPKEY_SERVER_WRAP_VERSION) {
+ return bkrp_server_wrap_decrypt_data(dce_call, mem_ctx, r, ldb_ctx);
+ }
+
+ return bkrp_client_wrap_decrypt_data(dce_call, mem_ctx, r, ldb_ctx);
+}
+
+/*
+ * We have some data, such as saved website or IMAP passwords that the
+ * client would like to put into the profile on-disk. This needs to
+ * be encrypted. This version gives the server the data over the
+ * network (protected only by the negotiated transport encryption),
+ * and asks that it be encrypted and returned for long-term storage.
+ *
+ * The data is NOT stored in the LSA, but a key to encrypt the data
+ * will be stored. There is only one active encryption key per domain,
+ * it is pointed at with G$BCKUPKEY_P in the LSA secrets store.
+ *
+ * The potentially multiple valid decryptiong keys (and the encryption
+ * key) are in turn stored in the LSA secrets store as
+ * G$BCKUPKEY_keyGuidString.
+ *
+ */
+
+static WERROR bkrp_server_wrap_encrypt_data(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+ struct bkrp_BackupKey *r ,struct ldb_context *ldb_ctx)
+{
+ DATA_BLOB sid_blob, encrypted_blob, server_wrapped_blob;
+ WERROR werr;
+ struct dom_sid *caller_sid;
+ uint8_t symkey[20]; /* SHA-1 hash len */
+ uint8_t mackey[20]; /* SHA-1 hash len */
+ struct bkrp_rc4encryptedpayload rc4payload;
+ gnutls_hmac_hd_t hmac_hnd;
+ struct bkrp_dc_serverwrap_key server_key;
+ enum ndr_err_code ndr_err;
+ struct bkrp_server_side_wrapped server_side_wrapped;
+ struct GUID guid;
+ gnutls_cipher_hd_t cipher_hnd;
+ gnutls_datum_t cipher_key;
+ int rc;
+
+ if (r->in.data_in_len == 0 || r->in.data_in == NULL) {
+ return WERR_INVALID_PARAM;
+ }
+
+ werr = bkrp_do_retrieve_default_server_wrap_key(mem_ctx,
+ ldb_ctx, &server_key,
+ &guid);
+
+ if (!W_ERROR_IS_OK(werr)) {
+ if (W_ERROR_EQUAL(werr, WERR_FILE_NOT_FOUND)) {
+ /* Generate the server wrap key since one wasn't found */
+ werr = generate_bkrp_server_wrap_key(mem_ctx,
+ ldb_ctx);
+ if (!W_ERROR_IS_OK(werr)) {
+ return WERR_INVALID_PARAMETER;
+ }
+ werr = bkrp_do_retrieve_default_server_wrap_key(mem_ctx,
+ ldb_ctx,
+ &server_key,
+ &guid);
+
+ if (W_ERROR_EQUAL(werr, WERR_FILE_NOT_FOUND)) {
+ /* Ok we really don't manage to get this secret ...*/
+ return WERR_FILE_NOT_FOUND;
+ }
+ } else {
+ /* In theory we should NEVER reach this point as it
+ should only appear in a rodc server */
+ /* we do not have the real secret attribute */
+ return WERR_INVALID_PARAMETER;
+ }
+ }
+
+ caller_sid = &dce_call->conn->auth_state.session_info->security_token->sids[PRIMARY_USER_SID_INDEX];
+
+ dump_data_pw("server_key: \n", server_key.key, sizeof(server_key.key));
+
+ /*
+ * This is the key derivation step, so that the HMAC and RC4
+ * operations over the user-supplied data are not able to
+ * disclose the master key. By using random data, the symkey
+ * and mackey values are unique for this operation, and
+ * discovering these (by reversing the RC4 over the
+ * attacker-controlled data) does not return something able to
+ * be used to decyrpt the encrypted data of other users
+ */
+ generate_random_buffer(server_side_wrapped.r2, sizeof(server_side_wrapped.r2));
+
+ dump_data_pw("r2: \n", server_side_wrapped.r2, sizeof(server_side_wrapped.r2));
+
+ generate_random_buffer(rc4payload.r3, sizeof(rc4payload.r3));
+
+ dump_data_pw("r3: \n", rc4payload.r3, sizeof(rc4payload.r3));
+
+
+ /*
+ * This is *not* the leading 64 bytes, as indicated in MS-BKRP 3.1.4.1.1
+ * BACKUPKEY_BACKUP_GUID, it really is the whole key
+ */
+ gnutls_hmac_init(&hmac_hnd,
+ GNUTLS_MAC_SHA1,
+ server_key.key,
+ sizeof(server_key.key));
+ gnutls_hmac(hmac_hnd,
+ server_side_wrapped.r2,
+ sizeof(server_side_wrapped.r2));
+ gnutls_hmac_output(hmac_hnd, symkey);
+
+ dump_data_pw("symkey: \n", symkey, sizeof(symkey));
+
+ /*
+ * This is *not* the leading 64 bytes, as indicated in MS-BKRP 3.1.4.1.1
+ * BACKUPKEY_BACKUP_GUID, it really is the whole key
+ */
+ gnutls_hmac(hmac_hnd,
+ rc4payload.r3,
+ sizeof(rc4payload.r3));
+ gnutls_hmac_deinit(hmac_hnd, mackey);
+
+ dump_data_pw("mackey: \n", mackey, sizeof(mackey));
+
+ ndr_err = ndr_push_struct_blob(&sid_blob, mem_ctx, caller_sid,
+ (ndr_push_flags_fn_t)ndr_push_dom_sid);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INTERNAL_ERROR;
+ }
+
+ rc4payload.secret_data.data = r->in.data_in;
+ rc4payload.secret_data.length = r->in.data_in_len;
+
+ gnutls_hmac_init(&hmac_hnd,
+ GNUTLS_MAC_SHA1,
+ mackey,
+ sizeof(mackey));
+ /* SID field */
+ gnutls_hmac(hmac_hnd,
+ sid_blob.data,
+ sid_blob.length);
+ /* Secret field */
+ gnutls_hmac(hmac_hnd,
+ rc4payload.secret_data.data,
+ rc4payload.secret_data.length);
+ gnutls_hmac_deinit(hmac_hnd, rc4payload.mac);
+
+ dump_data_pw("rc4payload.mac: \n", rc4payload.mac, sizeof(rc4payload.mac));
+
+ rc4payload.sid = *caller_sid;
+
+ ndr_err = ndr_push_struct_blob(&encrypted_blob, mem_ctx, &rc4payload,
+ (ndr_push_flags_fn_t)ndr_push_bkrp_rc4encryptedpayload);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INTERNAL_ERROR;
+ }
+
+ /* rc4 encrypt sid and secret using sym key */
+ cipher_key.data = symkey;
+ cipher_key.size = sizeof(symkey);
+
+ rc = gnutls_cipher_init(&cipher_hnd,
+ GNUTLS_CIPHER_ARCFOUR_128,
+ &cipher_key,
+ NULL);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_cipher_init failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_PARAM;
+ }
+ rc = gnutls_cipher_encrypt2(cipher_hnd,
+ encrypted_blob.data,
+ encrypted_blob.length,
+ encrypted_blob.data,
+ encrypted_blob.length);
+ gnutls_cipher_deinit(cipher_hnd);
+ if (rc != GNUTLS_E_SUCCESS) {
+ DBG_ERR("gnutls_cipher_encrypt2 failed - %s\n",
+ gnutls_strerror(rc));
+ return WERR_INVALID_PARAM;
+ }
+
+ /* create server wrap structure */
+
+ server_side_wrapped.payload_length = rc4payload.secret_data.length;
+ server_side_wrapped.ciphertext_length = encrypted_blob.length;
+ server_side_wrapped.guid = guid;
+ server_side_wrapped.rc4encryptedpayload = encrypted_blob.data;
+
+ ndr_err = ndr_push_struct_blob(&server_wrapped_blob, mem_ctx, &server_side_wrapped,
+ (ndr_push_flags_fn_t)ndr_push_bkrp_server_side_wrapped);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_INTERNAL_ERROR;
+ }
+
+ *(r->out.data_out) = server_wrapped_blob.data;
+ *(r->out.data_out_len) = server_wrapped_blob.length;
+
+ return WERR_OK;
+}
+
+static WERROR dcesrv_bkrp_BackupKey(struct dcesrv_call_state *dce_call,
+ TALLOC_CTX *mem_ctx, struct bkrp_BackupKey *r)
+{
+ WERROR error = WERR_INVALID_PARAM;
+ struct ldb_context *ldb_ctx;
+ bool is_rodc;
+ const char *addr = "unknown";
+ /* At which level we start to add more debug of what is done in the protocol */
+ const int debuglevel = 4;
+
+ gnutls_global_init();
+
+ if (DEBUGLVL(debuglevel)) {
+ const struct tsocket_address *remote_address;
+ remote_address = dcesrv_connection_get_remote_address(dce_call->conn);
+ if (tsocket_address_is_inet(remote_address, "ip")) {
+ addr = tsocket_address_inet_addr_string(remote_address, mem_ctx);
+ W_ERROR_HAVE_NO_MEMORY(addr);
+ }
+ }
+
+ if (lpcfg_server_role(dce_call->conn->dce_ctx->lp_ctx) != ROLE_ACTIVE_DIRECTORY_DC) {
+ return WERR_NOT_SUPPORTED;
+ }
+
+ if (!dce_call->conn->auth_state.auth_info ||
+ dce_call->conn->auth_state.auth_info->auth_level != DCERPC_AUTH_LEVEL_PRIVACY) {
+ DCESRV_FAULT(DCERPC_FAULT_ACCESS_DENIED);
+ }
+
+ ldb_ctx = samdb_connect(mem_ctx, dce_call->event_ctx,
+ dce_call->conn->dce_ctx->lp_ctx,
+ system_session(dce_call->conn->dce_ctx->lp_ctx), 0);
+
+ if (samdb_rodc(ldb_ctx, &is_rodc) != LDB_SUCCESS) {
+ talloc_unlink(mem_ctx, ldb_ctx);
+ return WERR_INVALID_PARAM;
+ }
+
+ if (!is_rodc) {
+ if(strncasecmp(GUID_string(mem_ctx, r->in.guidActionAgent),
+ BACKUPKEY_RESTORE_GUID, strlen(BACKUPKEY_RESTORE_GUID)) == 0) {
+ DEBUG(debuglevel, ("Client %s requested to decrypt a wrapped secret\n", addr));
+ error = bkrp_generic_decrypt_data(dce_call, mem_ctx, r, ldb_ctx);
+ }
+
+ if (strncasecmp(GUID_string(mem_ctx, r->in.guidActionAgent),
+ BACKUPKEY_RETRIEVE_BACKUP_KEY_GUID, strlen(BACKUPKEY_RETRIEVE_BACKUP_KEY_GUID)) == 0) {
+ DEBUG(debuglevel, ("Client %s requested certificate for client wrapped secret\n", addr));
+ error = bkrp_retrieve_client_wrap_key(dce_call, mem_ctx, r, ldb_ctx);
+ }
+
+ if (strncasecmp(GUID_string(mem_ctx, r->in.guidActionAgent),
+ BACKUPKEY_RESTORE_GUID_WIN2K, strlen(BACKUPKEY_RESTORE_GUID_WIN2K)) == 0) {
+ DEBUG(debuglevel, ("Client %s requested to decrypt a server side wrapped secret\n", addr));
+ error = bkrp_server_wrap_decrypt_data(dce_call, mem_ctx, r, ldb_ctx);
+ }
+
+ if (strncasecmp(GUID_string(mem_ctx, r->in.guidActionAgent),
+ BACKUPKEY_BACKUP_GUID, strlen(BACKUPKEY_BACKUP_GUID)) == 0) {
+ DEBUG(debuglevel, ("Client %s requested a server wrapped secret\n", addr));
+ error = bkrp_server_wrap_encrypt_data(dce_call, mem_ctx, r, ldb_ctx);
+ }
+ }
+ /*else: I am a RODC so I don't handle backup key protocol */
+
+ gnutls_global_deinit();
+ talloc_unlink(mem_ctx, ldb_ctx);
+ return error;
+}
+
+/* include the generated boilerplate */
+#include "librpc/gen_ndr/ndr_backupkey_s.c"
git.samba.org / obnox / samba / samba-obnox.git / commitdiff