code to manipulate domain credentials
Copyright (C) Andrew Tridgell 1997-2003
+ Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
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 2 of the License, or
+ 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,
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, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
+#include "system/time.h"
+#include "auth/auth.h"
+#include "lib/crypto/crypto.h"
+#include "libcli/auth/libcli_auth.h"
/*
- initialise the credentials state
+ initialise the credentials state for old-style 64 bit session keys
+
+ this call is made after the netr_ServerReqChallenge call
*/
-void creds_init(struct netr_CredentialState *creds,
- const struct netr_Credential *client_challenge,
- const struct netr_Credential *server_challenge,
- const uint8 machine_password[16])
+static void creds_init_64bit(struct creds_CredentialState *creds,
+ const struct netr_Credential *client_challenge,
+ const struct netr_Credential *server_challenge,
+ const struct samr_Password *machine_password)
{
- struct netr_Credential time_cred;
- uint32 sum[2];
- uint8 sum2[8];
+ uint32_t sum[2];
+ uint8_t sum2[8];
sum[0] = IVAL(client_challenge->data, 0) + IVAL(server_challenge->data, 0);
sum[1] = IVAL(client_challenge->data, 4) + IVAL(server_challenge->data, 4);
SIVAL(sum2,0,sum[0]);
SIVAL(sum2,4,sum[1]);
- cred_hash1(creds->session_key, sum2, machine_password);
+ ZERO_STRUCT(creds->session_key);
+
+ des_crypt128(creds->session_key, sum2, machine_password->hash);
+
+ des_crypt112(creds->client.data, client_challenge->data, creds->session_key, 1);
+ des_crypt112(creds->server.data, server_challenge->data, creds->session_key, 1);
+
+ creds->seed = creds->client;
+}
+
+/*
+ initialise the credentials state for ADS-style 128 bit session keys
+
+ this call is made after the netr_ServerReqChallenge call
+*/
+static void creds_init_128bit(struct creds_CredentialState *creds,
+ const struct netr_Credential *client_challenge,
+ const struct netr_Credential *server_challenge,
+ const struct samr_Password *machine_password)
+{
+ unsigned char zero[4], tmp[16];
+ HMACMD5Context ctx;
+ struct MD5Context md5;
+
+ ZERO_STRUCT(creds->session_key);
+
+ memset(zero, 0, sizeof(zero));
- creds->sequence = 0;
+ hmac_md5_init_rfc2104(machine_password->hash, sizeof(machine_password->hash), &ctx);
+ MD5Init(&md5);
+ MD5Update(&md5, zero, sizeof(zero));
+ MD5Update(&md5, client_challenge->data, 8);
+ MD5Update(&md5, server_challenge->data, 8);
+ MD5Final(tmp, &md5);
+ hmac_md5_update(tmp, sizeof(tmp), &ctx);
+ hmac_md5_final(creds->session_key, &ctx);
- SIVAL(time_cred.data, 0, IVAL(client_challenge->data, 0) + creds->sequence);
- SIVAL(time_cred.data, 4, IVAL(client_challenge->data, 4));
+ creds->client = *client_challenge;
+ creds->server = *server_challenge;
- cred_hash2(creds->client_cred.data, time_cred.data, creds->session_key);
+ des_crypt112(creds->client.data, client_challenge->data, creds->session_key, 1);
+ des_crypt112(creds->server.data, server_challenge->data, creds->session_key, 1);
- creds->server_cred = *server_challenge;
+ creds->seed = creds->client;
}
+
/*
- check that the credentials reply is correct then generate the next
- set of credentials
+ step the credentials to the next element in the chain, updating the
+ current client and server credentials and the seed
*/
-BOOL creds_next(struct netr_CredentialState *creds,
- const struct netr_Credential *next)
+static void creds_step(struct creds_CredentialState *creds)
{
- struct netr_Credential cred2;
struct netr_Credential time_cred;
- SIVAL(time_cred.data, 0, IVAL(creds->server_cred.data, 0) + creds->sequence);
- SIVAL(time_cred.data, 4, IVAL(creds->server_cred.data, 4));
- cred_hash2(cred2.data, time_cred.data, creds->session_key);
- if (memcmp(next->data, cred2.data, 8) != 0) {
+ DEBUG(5,("\tseed %08x:%08x\n",
+ IVAL(creds->seed.data, 0), IVAL(creds->seed.data, 4)));
+
+ SIVAL(time_cred.data, 0, IVAL(creds->seed.data, 0) + creds->sequence);
+ SIVAL(time_cred.data, 4, IVAL(creds->seed.data, 4));
+
+ DEBUG(5,("\tseed+time %08x:%08x\n", IVAL(time_cred.data, 0), IVAL(time_cred.data, 4)));
+
+ des_crypt112(creds->client.data, time_cred.data, creds->session_key, 1);
+
+ DEBUG(5,("\tCLIENT %08x:%08x\n",
+ IVAL(creds->client.data, 0), IVAL(creds->client.data, 4)));
+
+ SIVAL(time_cred.data, 0, IVAL(creds->seed.data, 0) + creds->sequence + 1);
+ SIVAL(time_cred.data, 4, IVAL(creds->seed.data, 4));
+
+ DEBUG(5,("\tseed+time+1 %08x:%08x\n",
+ IVAL(time_cred.data, 0), IVAL(time_cred.data, 4)));
+
+ des_crypt112(creds->server.data, time_cred.data, creds->session_key, 1);
+
+ DEBUG(5,("\tSERVER %08x:%08x\n",
+ IVAL(creds->server.data, 0), IVAL(creds->server.data, 4)));
+
+ creds->seed = time_cred;
+}
+
+
+/*
+ DES encrypt a 8 byte LMSessionKey buffer using the Netlogon session key
+*/
+void creds_des_encrypt_LMKey(struct creds_CredentialState *creds, struct netr_LMSessionKey *key)
+{
+ struct netr_LMSessionKey tmp;
+ des_crypt56(tmp.key, key->key, creds->session_key, 1);
+ *key = tmp;
+}
+
+/*
+ DES decrypt a 8 byte LMSessionKey buffer using the Netlogon session key
+*/
+void creds_des_decrypt_LMKey(struct creds_CredentialState *creds, struct netr_LMSessionKey *key)
+{
+ struct netr_LMSessionKey tmp;
+ des_crypt56(tmp.key, key->key, creds->session_key, 0);
+ *key = tmp;
+}
+
+/*
+ DES encrypt a 16 byte password buffer using the session key
+*/
+void creds_des_encrypt(struct creds_CredentialState *creds, struct samr_Password *pass)
+{
+ struct samr_Password tmp;
+ des_crypt112_16(tmp.hash, pass->hash, creds->session_key, 1);
+ *pass = tmp;
+}
+
+/*
+ DES decrypt a 16 byte password buffer using the session key
+*/
+void creds_des_decrypt(struct creds_CredentialState *creds, struct samr_Password *pass)
+{
+ struct samr_Password tmp;
+ des_crypt112_16(tmp.hash, pass->hash, creds->session_key, 0);
+ *pass = tmp;
+}
+
+/*
+ ARCFOUR encrypt/decrypt a password buffer using the session key
+*/
+void creds_arcfour_crypt(struct creds_CredentialState *creds, uint8_t *data, size_t len)
+{
+ DATA_BLOB session_key = data_blob(creds->session_key, 16);
+
+ arcfour_crypt_blob(data, len, &session_key);
+
+ data_blob_free(&session_key);
+}
+
+/*****************************************************************
+The above functions are common to the client and server interface
+next comes the client specific functions
+******************************************************************/
+
+/*
+ initialise the credentials chain and return the first client
+ credentials
+*/
+void creds_client_init(struct creds_CredentialState *creds,
+ const struct netr_Credential *client_challenge,
+ const struct netr_Credential *server_challenge,
+ const struct samr_Password *machine_password,
+ struct netr_Credential *initial_credential,
+ uint32_t negotiate_flags)
+{
+ creds->sequence = time(NULL);
+ creds->negotiate_flags = negotiate_flags;
+
+ dump_data_pw("Client chall", client_challenge->data, sizeof(client_challenge->data));
+ dump_data_pw("Server chall", server_challenge->data, sizeof(server_challenge->data));
+ dump_data_pw("Machine Pass", machine_password->hash, sizeof(machine_password->hash));
+
+ if (negotiate_flags & NETLOGON_NEG_128BIT) {
+ creds_init_128bit(creds, client_challenge, server_challenge, machine_password);
+ } else {
+ creds_init_64bit(creds, client_challenge, server_challenge, machine_password);
+ }
+
+ dump_data_pw("Session key", creds->session_key, 16);
+ dump_data_pw("Credential ", creds->client.data, 8);
+
+ *initial_credential = creds->client;
+}
+
+/*
+ step the credentials to the next element in the chain, updating the
+ current client and server credentials and the seed
+
+ produce the next authenticator in the sequence ready to send to
+ the server
+*/
+void creds_client_authenticator(struct creds_CredentialState *creds,
+ struct netr_Authenticator *next)
+{
+ creds->sequence += 2;
+ creds_step(creds);
+
+ next->cred = creds->client;
+ next->timestamp = creds->sequence;
+}
+
+/*
+ check that a credentials reply from a server is correct
+*/
+BOOL creds_client_check(struct creds_CredentialState *creds,
+ const struct netr_Credential *received_credentials)
+{
+ if (!received_credentials ||
+ memcmp(received_credentials->data, creds->server.data, 8) != 0) {
DEBUG(2,("credentials check failed\n"));
return False;
}
+ return True;
+}
- creds->server_cred = creds->client_cred;
- SIVAL(time_cred.data, 0, IVAL(creds->client_cred.data, 0) + creds->sequence);
- SIVAL(time_cred.data, 4, IVAL(creds->client_cred.data, 4));
+/*****************************************************************
+The above functions are common to the client and server interface
+next comes the server specific functions
+******************************************************************/
- cred_hash2(cred2.data, time_cred.data, creds->session_key);
+/*
+ initialise the credentials chain and return the first server
+ credentials
+*/
+void creds_server_init(struct creds_CredentialState *creds,
+ const struct netr_Credential *client_challenge,
+ const struct netr_Credential *server_challenge,
+ const struct samr_Password *machine_password,
+ struct netr_Credential *initial_credential,
+ uint32_t negotiate_flags)
+{
+ if (negotiate_flags & NETLOGON_NEG_128BIT) {
+ creds_init_128bit(creds, client_challenge, server_challenge,
+ machine_password);
+ } else {
+ creds_init_64bit(creds, client_challenge, server_challenge,
+ machine_password);
+ }
+
+ *initial_credential = creds->server;
+ creds->negotiate_flags = negotiate_flags;
+}
- creds->client_cred = cred2;
- creds->sequence++;
+/*
+ check that a credentials reply from a server is correct
+*/
+BOOL creds_server_check(const struct creds_CredentialState *creds,
+ const struct netr_Credential *received_credentials)
+{
+ if (memcmp(received_credentials->data, creds->client.data, 8) != 0) {
+ DEBUG(2,("credentials check failed\n"));
+ dump_data_pw("client creds", creds->client.data, 8);
+ dump_data_pw("calc creds", received_credentials->data, 8);
+ return False;
+ }
return True;
}
+
+NTSTATUS creds_server_step_check(struct creds_CredentialState *creds,
+ struct netr_Authenticator *received_authenticator,
+ struct netr_Authenticator *return_authenticator)
+{
+ if (!received_authenticator || !return_authenticator) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ if (!creds) {
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ /* TODO: this may allow the a replay attack on a non-signed
+ connection. Should we check that this is increasing? */
+ creds->sequence = received_authenticator->timestamp;
+ creds_step(creds);
+ if (creds_server_check(creds, &received_authenticator->cred)) {
+ return_authenticator->cred = creds->server;
+ return_authenticator->timestamp = creds->sequence;
+ return NT_STATUS_OK;
+ } else {
+ ZERO_STRUCTP(return_authenticator);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+}
+
+void creds_decrypt_samlogon(struct creds_CredentialState *creds,
+ uint16_t validation_level,
+ union netr_Validation *validation)
+{
+ static const char zeros[16];
+
+ struct netr_SamBaseInfo *base = NULL;
+ switch (validation_level) {
+ case 2:
+ if (validation->sam2) {
+ base = &validation->sam2->base;
+ }
+ break;
+ case 3:
+ if (validation->sam3) {
+ base = &validation->sam3->base;
+ }
+ break;
+ case 6:
+ if (validation->sam6) {
+ base = &validation->sam6->base;
+ }
+ break;
+ default:
+ /* If we can't find it, we can't very well decrypt it */
+ return;
+ }
+
+ if (!base) {
+ return;
+ }
+
+ /* find and decyrpt the session keys, return in parameters above */
+ if (validation_level == 6) {
+ /* they aren't encrypted! */
+ } else if (creds->negotiate_flags & NETLOGON_NEG_ARCFOUR) {
+ if (memcmp(base->key.key, zeros,
+ sizeof(base->key.key)) != 0) {
+ creds_arcfour_crypt(creds,
+ base->key.key,
+ sizeof(base->key.key));
+ }
+
+ if (memcmp(base->LMSessKey.key, zeros,
+ sizeof(base->LMSessKey.key)) != 0) {
+ creds_arcfour_crypt(creds,
+ base->LMSessKey.key,
+ sizeof(base->LMSessKey.key));
+ }
+ } else {
+ if (memcmp(base->LMSessKey.key, zeros,
+ sizeof(base->LMSessKey.key)) != 0) {
+ creds_des_decrypt_LMKey(creds,
+ &base->LMSessKey);
+ }
+ }
+}
git.samba.org / kai / samba-autobuild / .git / blobdiff