Example #1
0
static NTSTATUS authsam_authenticate(struct auth_context *auth_context, 
				     TALLOC_CTX *mem_ctx, struct ldb_context *sam_ctx, 
				     struct ldb_dn *domain_dn,
				     struct ldb_message *msg,
				     const struct auth_usersupplied_info *user_info, 
				     DATA_BLOB *user_sess_key, DATA_BLOB *lm_sess_key) 
{
	struct samr_Password *lm_pwd, *nt_pwd;
	NTSTATUS nt_status;

	uint16_t acct_flags = samdb_result_acct_flags(sam_ctx, mem_ctx, msg, domain_dn);
	
	/* Quit if the account was locked out. */
	if (acct_flags & ACB_AUTOLOCK) {
		DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", 
			 user_info->mapped.account_name));
		return NT_STATUS_ACCOUNT_LOCKED_OUT;
	}

	/* You can only do an interactive login to normal accounts */
	if (user_info->flags & USER_INFO_INTERACTIVE_LOGON) {
		if (!(acct_flags & ACB_NORMAL)) {
			return NT_STATUS_NO_SUCH_USER;
		}
	}

	nt_status = samdb_result_passwords(mem_ctx, auth_context->lp_ctx, msg, &lm_pwd, &nt_pwd);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	nt_status = authsam_password_ok(auth_context, mem_ctx, 
					acct_flags, lm_pwd, nt_pwd,
					user_info, user_sess_key, lm_sess_key);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	nt_status = authsam_account_ok(mem_ctx, sam_ctx, 
				       user_info->logon_parameters,
				       domain_dn,
				       msg,
				       user_info->workstation_name,
				       user_info->mapped.account_name,
				       false, false);

	return nt_status;
}
Example #2
0
static NTSTATUS authsam_authenticate(struct auth_context *auth_context, 
				     TALLOC_CTX *mem_ctx, struct ldb_context *sam_ctx, 
				     struct ldb_dn *domain_dn,
				     struct ldb_message *msg,
				     const struct auth_usersupplied_info *user_info, 
				     DATA_BLOB *user_sess_key, DATA_BLOB *lm_sess_key) 
{
	struct samr_Password *lm_pwd, *nt_pwd;
	NTSTATUS nt_status;

	uint16_t acct_flags = samdb_result_acct_flags(auth_context->sam_ctx, mem_ctx, msg, domain_dn);
	
	/* Quit if the account was locked out. */
	if (acct_flags & ACB_AUTOLOCK) {
		DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", 
			 user_info->mapped.account_name));
		return NT_STATUS_ACCOUNT_LOCKED_OUT;
	}

	/* You can only do an interactive login to normal accounts */
	if (user_info->flags & USER_INFO_INTERACTIVE_LOGON) {
		if (!(acct_flags & ACB_NORMAL)) {
			return NT_STATUS_NO_SUCH_USER;
		}
	}

	nt_status = samdb_result_passwords(mem_ctx, auth_context->lp_ctx, msg, &lm_pwd, &nt_pwd);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	if (lm_pwd == NULL && nt_pwd == NULL) {
		bool am_rodc;
		if (samdb_rodc(auth_context->sam_ctx, &am_rodc) == LDB_SUCCESS && am_rodc) {
			/* we don't have passwords for this
			 * account. We are an RODC, and this account
			 * may be one for which we either are denied
			 * REPL_SECRET replication or we haven't yet
			 * done the replication. We return
			 * NT_STATUS_NOT_IMPLEMENTED which tells the
			 * auth code to try the next authentication
			 * mechanism. We also send a message to our
			 * drepl server to tell it to try and
			 * replicate the secrets for this account.
			 */
			auth_sam_trigger_repl_secret(mem_ctx, auth_context, msg->dn);
			return NT_STATUS_NOT_IMPLEMENTED;
		}
	}

	nt_status = authsam_password_ok(auth_context, mem_ctx, 
					acct_flags, lm_pwd, nt_pwd,
					user_info, user_sess_key, lm_sess_key);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	nt_status = authsam_account_ok(mem_ctx, auth_context->sam_ctx,
				       user_info->logon_parameters,
				       domain_dn,
				       msg,
				       user_info->workstation_name,
				       user_info->mapped.account_name,
				       false, false);

	return nt_status;
}
Example #3
0
static NTSTATUS authsam_password_check_and_record(struct auth4_context *auth_context,
						  TALLOC_CTX *mem_ctx,
						  struct ldb_dn *domain_dn,
						  struct ldb_message *msg,
						  uint16_t acct_flags,
						  const struct auth_usersupplied_info *user_info,
						  DATA_BLOB *user_sess_key,
						  DATA_BLOB *lm_sess_key,
						  bool *authoritative)
{
	NTSTATUS nt_status;
	NTSTATUS auth_status;
	TALLOC_CTX *tmp_ctx;
	int i, ret;
	int history_len = 0;
	struct ldb_context *sam_ctx = auth_context->sam_ctx;
	const char * const attrs[] = { "pwdHistoryLength", NULL };
	struct ldb_message *dom_msg;
	struct samr_Password *lm_pwd;
	struct samr_Password *nt_pwd;
	bool am_rodc;

	tmp_ctx = talloc_new(mem_ctx);
	if (tmp_ctx == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	/*
	 * This call does more than what it appears to do, it also
	 * checks for the account lockout.
	 *
	 * It is done here so that all parts of Samba that read the
	 * password refuse to even operate on it if the account is
	 * locked out, to avoid mistakes like CVE-2013-4496.
	 */
	nt_status = samdb_result_passwords(tmp_ctx, auth_context->lp_ctx,
					   msg, &lm_pwd, &nt_pwd);
	if (!NT_STATUS_IS_OK(nt_status)) {
		TALLOC_FREE(tmp_ctx);
		return nt_status;
	}

	if (lm_pwd == NULL && nt_pwd == NULL) {
		if (samdb_rodc(auth_context->sam_ctx, &am_rodc) == LDB_SUCCESS && am_rodc) {
			/*
			 * we don't have passwords for this
			 * account. We are an RODC, and this account
			 * may be one for which we either are denied
			 * REPL_SECRET replication or we haven't yet
			 * done the replication. We return
			 * NT_STATUS_NOT_IMPLEMENTED which tells the
			 * auth code to try the next authentication
			 * mechanism. We also send a message to our
			 * drepl server to tell it to try and
			 * replicate the secrets for this account.
			 *
			 * TODO: Should we only trigger this is detected
			 * there's a chance that the password might be
			 * replicated, we should be able to detect this
			 * based on msDS-NeverRevealGroup.
			 */
			auth_sam_trigger_repl_secret(auth_context,
						     auth_context->msg_ctx,
						     auth_context->event_ctx,
						     msg->dn);
			TALLOC_FREE(tmp_ctx);
			return NT_STATUS_NOT_IMPLEMENTED;
		}
	}

	auth_status = authsam_password_ok(auth_context, tmp_ctx,
					  acct_flags,
					  lm_pwd, nt_pwd,
					  user_info,
					  user_sess_key, lm_sess_key);
	if (NT_STATUS_IS_OK(auth_status)) {
		if (user_sess_key->data) {
			talloc_steal(mem_ctx, user_sess_key->data);
		}
		if (lm_sess_key->data) {
			talloc_steal(mem_ctx, lm_sess_key->data);
		}
		TALLOC_FREE(tmp_ctx);
		return NT_STATUS_OK;
	}
	*user_sess_key = data_blob_null;
	*lm_sess_key = data_blob_null;

	if (!NT_STATUS_EQUAL(auth_status, NT_STATUS_WRONG_PASSWORD)) {
		TALLOC_FREE(tmp_ctx);
		return auth_status;
	}

	/*
	 * We only continue if this was a wrong password
	 * and we'll always return NT_STATUS_WRONG_PASSWORD
	 * no matter what error happens.
	 */

	/* pull the domain password property attributes */
	ret = dsdb_search_one(sam_ctx, tmp_ctx, &dom_msg, domain_dn, LDB_SCOPE_BASE,
			      attrs, 0, "objectClass=domain");
	if (ret == LDB_SUCCESS) {
		history_len = ldb_msg_find_attr_as_uint(dom_msg, "pwdHistoryLength", 0);
	} else if (ret == LDB_ERR_NO_SUCH_OBJECT) {
		DEBUG(3,("Couldn't find domain %s: %s!\n",
			 ldb_dn_get_linearized(domain_dn),
			 ldb_errstring(sam_ctx)));
	} else {
		DEBUG(3,("error finding domain %s: %s!\n",
			 ldb_dn_get_linearized(domain_dn),
			 ldb_errstring(sam_ctx)));
	}

	for (i = 1; i < MIN(history_len, 3); i++) {
		struct samr_Password zero_string_hash;
		struct samr_Password zero_string_des_hash;
		struct samr_Password *nt_history_pwd = NULL;
		struct samr_Password *lm_history_pwd = NULL;
		NTTIME pwdLastSet;
		struct timeval tv_now;
		NTTIME now;
		int allowed_period_mins;
		NTTIME allowed_period;

		nt_status = samdb_result_passwords_from_history(tmp_ctx,
							auth_context->lp_ctx,
							msg, i,
							&lm_history_pwd,
							&nt_history_pwd);
		if (!NT_STATUS_IS_OK(nt_status)) {
			/*
			 * If we don't find element 'i' we won't find
			 * 'i+1' ...
			 */
			break;
		}

		/*
		 * We choose to avoid any issues
		 * around different LM and NT history
		 * lengths by only checking the NT
		 * history
		 */
		if (nt_history_pwd == NULL) {
			/*
			 * If we don't find element 'i' we won't find
			 * 'i+1' ...
			 */
			break;
		}

		/* Skip over all-zero hashes in the history */
		if (all_zero(nt_history_pwd->hash,
			     sizeof(nt_history_pwd->hash))) {
			continue;
		}

		/*
		 * This looks odd, but the password_hash module writes this in if
		 * (somehow) we didn't have an old NT hash
		 */

		E_md4hash("", zero_string_hash.hash);
		if (memcmp(nt_history_pwd->hash, zero_string_hash.hash, 16) == 0) {
			continue;
		}

		E_deshash("", zero_string_des_hash.hash);
		if (!lm_history_pwd || memcmp(lm_history_pwd->hash, zero_string_des_hash.hash, 16) == 0) {
			lm_history_pwd = NULL;
		}

		auth_status = authsam_password_ok(auth_context, tmp_ctx,
						  acct_flags,
						  lm_history_pwd,
						  nt_history_pwd,
						  user_info,
						  user_sess_key,
						  lm_sess_key);
		if (!NT_STATUS_IS_OK(auth_status)) {
			/*
			 * If this was not a correct password, try the next
			 * one from the history
			 */
			*user_sess_key = data_blob_null;
			*lm_sess_key = data_blob_null;
			continue;
		}

		if (i != 1) {
			/*
			 * The authentication was OK, but not against
			 * the previous password, which is stored at index 1.
			 *
			 * We just return the original wrong password.
			 * This skips the update of the bad pwd count,
			 * because this is almost certainly user error
			 * (or automatic login on a computer using a cached
			 * password from before the password change),
			 * not an attack.
			 */
			TALLOC_FREE(tmp_ctx);
			return NT_STATUS_WRONG_PASSWORD;
		}

		if (user_info->password_state != AUTH_PASSWORD_RESPONSE) {
			/*
			 * The authentication was OK against the previous password,
			 * but it's not a NTLM network authentication.
			 *
			 * We just return the original wrong password.
			 * This skips the update of the bad pwd count,
			 * because this is almost certainly user error
			 * (or automatic login on a computer using a cached
			 * password from before the password change),
			 * not an attack.
			 */
			TALLOC_FREE(tmp_ctx);
			return NT_STATUS_WRONG_PASSWORD;
		}

		/*
		 * If the password was OK, it's a NTLM network authentication
		 * and it was the previous password.
		 *
		 * Now we see if it is within the grace period,
		 * so that we don't break cached sessions on other computers
		 * before the user can lock and unlock their other screens
		 * (resetting their cached password).
		 *
		 * See http://support.microsoft.com/kb/906305
		 * OldPasswordAllowedPeriod ("old password allowed period")
		 * is specified in minutes. The default is 60.
		 */
		allowed_period_mins = lpcfg_old_password_allowed_period(auth_context->lp_ctx);
		/*
		 * NTTIME uses 100ns units
		 */
		allowed_period = allowed_period_mins * 60 * 1000*1000*10;
		pwdLastSet = samdb_result_nttime(msg, "pwdLastSet", 0);
		tv_now = timeval_current();
		now = timeval_to_nttime(&tv_now);

		if (now < pwdLastSet) {
			/*
			 * time jump?
			 *
			 * We just return the original wrong password.
			 * This skips the update of the bad pwd count,
			 * because this is almost certainly user error
			 * (or automatic login on a computer using a cached
			 * password from before the password change),
			 * not an attack.
			 */
			TALLOC_FREE(tmp_ctx);
			return NT_STATUS_WRONG_PASSWORD;
		}

		if ((now - pwdLastSet) >= allowed_period) {
			/*
			 * The allowed period is over.
			 *
			 * We just return the original wrong password.
			 * This skips the update of the bad pwd count,
			 * because this is almost certainly user error
			 * (or automatic login on a computer using a cached
			 * password from before the password change),
			 * not an attack.
			 */
			TALLOC_FREE(tmp_ctx);
			return NT_STATUS_WRONG_PASSWORD;
		}

		/*
		 * We finally allow the authentication with the
		 * previous password within the allowed period.
		 */
		if (user_sess_key->data) {
			talloc_steal(mem_ctx, user_sess_key->data);
		}
		if (lm_sess_key->data) {
			talloc_steal(mem_ctx, lm_sess_key->data);
		}

		TALLOC_FREE(tmp_ctx);
		return auth_status;
	}

	/*
	 * If we are not in the allowed period or match an old password,
	 * we didn't return early. Now update the badPwdCount et al.
	 */
	nt_status = authsam_update_bad_pwd_count(auth_context->sam_ctx,
						 msg, domain_dn);
	if (!NT_STATUS_IS_OK(nt_status)) {
		/*
		 * We need to return the original
		 * NT_STATUS_WRONG_PASSWORD error, so there isn't
		 * anything more we can do than write something into
		 * the log
		 */
		DEBUG(0, ("Failed to note bad password for user [%s]: %s\n",
			  user_info->mapped.account_name,
			  nt_errstr(nt_status)));
	}

	if (samdb_rodc(auth_context->sam_ctx, &am_rodc) == LDB_SUCCESS && am_rodc) {
		*authoritative = false;
	}

	TALLOC_FREE(tmp_ctx);
	return NT_STATUS_WRONG_PASSWORD;
}