/* Get the keytab (actually, a container containing the krb5_keytab)
* attached to this context. If this hasn't been done or set before,
* it will be generated from the password.
*/
_PUBLIC_ int cli_credentials_get_keytab(struct cli_credentials *cred,
struct loadparm_context *lp_ctx,
struct keytab_container **_ktc)
{
krb5_error_code ret;
struct keytab_container *ktc;
struct smb_krb5_context *smb_krb5_context;
const char *keytab_name;
krb5_keytab keytab;
TALLOC_CTX *mem_ctx;
if (cred->keytab_obtained >= (MAX(cred->principal_obtained,
cred->username_obtained))) {
*_ktc = cred->keytab;
return 0;
}
if (cli_credentials_is_anonymous(cred)) {
return EINVAL;
}
ret = cli_credentials_get_krb5_context(cred, lp_ctx,
&smb_krb5_context);
if (ret) {
return ret;
}
mem_ctx = talloc_new(cred);
if (!mem_ctx) {
return ENOMEM;
}
ret = smb_krb5_create_memory_keytab(mem_ctx,
smb_krb5_context->krb5_context,
cli_credentials_get_password(cred),
cli_credentials_get_username(cred),
cli_credentials_get_realm(cred),
cli_credentials_get_kvno(cred),
&keytab, &keytab_name);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
ret = smb_krb5_get_keytab_container(mem_ctx, smb_krb5_context,
keytab, keytab_name, &ktc);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
cred->keytab_obtained = (MAX(cred->principal_obtained,
cred->username_obtained));
/* We make this keytab up based on a password. Therefore
* match-by-key is acceptable, we can't match on the wrong
* principal */
ktc->password_based = true;
talloc_steal(cred, ktc);
cred->keytab = ktc;
*_ktc = cred->keytab;
talloc_free(mem_ctx);
return ret;
}
/* Get the keytab (actually, a container containing the krb5_keytab)
* attached to this context. If this hasn't been done or set before,
* it will be generated from the password.
*/
_PUBLIC_ int cli_credentials_get_keytab(struct cli_credentials *cred,
struct loadparm_context *lp_ctx,
struct keytab_container **_ktc)
{
krb5_error_code ret;
struct keytab_container *ktc;
struct smb_krb5_context *smb_krb5_context;
const char *keytab_name;
krb5_keytab keytab;
TALLOC_CTX *mem_ctx;
const char *username = cli_credentials_get_username(cred);
const char *realm = cli_credentials_get_realm(cred);
const char *error_string;
const char *salt_principal;
if (cred->keytab_obtained >= (MAX(cred->principal_obtained,
cred->username_obtained))) {
*_ktc = cred->keytab;
return 0;
}
if (cli_credentials_is_anonymous(cred)) {
return EINVAL;
}
ret = cli_credentials_get_krb5_context(cred, lp_ctx,
&smb_krb5_context);
if (ret) {
return ret;
}
mem_ctx = talloc_new(cred);
if (!mem_ctx) {
return ENOMEM;
}
/*
* FIXME: Currently there is no better way than to create the correct
* salt principal by checking if the username ends with a '$'. It would
* be better if it is part of the credentials.
*/
ret = smb_krb5_create_salt_principal(mem_ctx,
username,
realm,
&salt_principal,
&error_string);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
ret = smb_krb5_create_memory_keytab(mem_ctx,
smb_krb5_context->krb5_context,
cli_credentials_get_password(cred),
username,
realm,
salt_principal,
cli_credentials_get_kvno(cred),
&keytab,
&keytab_name);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
ret = smb_krb5_get_keytab_container(mem_ctx, smb_krb5_context,
keytab, keytab_name, &ktc);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
cred->keytab_obtained = (MAX(cred->principal_obtained,
cred->username_obtained));
/* We make this keytab up based on a password. Therefore
* match-by-key is acceptable, we can't match on the wrong
* principal */
ktc->password_based = true;
talloc_steal(cred, ktc);
cred->keytab = ktc;
*_ktc = cred->keytab;
talloc_free(mem_ctx);
return ret;
}
static int create_keytab(TALLOC_CTX *parent_ctx,
struct cli_credentials *machine_account,
struct smb_krb5_context *smb_krb5_context,
const char **enctype_strings,
krb5_keytab keytab,
BOOL add_old)
{
krb5_error_code ret;
const char *password_s;
const char *old_secret;
int kvno;
krb5_principal salt_princ;
krb5_principal princ;
const char *princ_string;
TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);
if (!mem_ctx) {
return ENOMEM;
}
princ_string = cli_credentials_get_principal(machine_account, mem_ctx);
/* Get the principal we will store the new keytab entries under */
ret = principal_from_credentials(mem_ctx, machine_account, smb_krb5_context, &princ);
if (ret) {
DEBUG(1,("create_keytab: makeing krb5 principal failed (%s)\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
return ret;
}
/* The salt used to generate these entries may be different however, fetch that */
ret = salt_principal_from_credentials(mem_ctx, machine_account,
smb_krb5_context,
&salt_princ);
if (ret) {
DEBUG(1,("create_keytab: makeing salt principal failed (%s)\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
return ret;
}
/* Finally, do the dance to get the password to put in the entry */
password_s = cli_credentials_get_password(machine_account);
if (!password_s) {
krb5_keytab_entry entry;
const struct samr_Password *mach_pwd;
if (!str_list_check(enctype_strings, "arcfour-hmac-md5")) {
DEBUG(1, ("Asked to create keytab, but with only an NT hash supplied, "
"but not listing arcfour-hmac-md5 as an enc type to include in the keytab!\n"));
talloc_free(mem_ctx);
return EINVAL;
}
/* If we don't have the plaintext password, try for
* the MD4 password hash */
mach_pwd = cli_credentials_get_nt_hash(machine_account, mem_ctx);
if (!mach_pwd) {
/* OK, nothing to do here */
talloc_free(mem_ctx);
return 0;
}
ret = krb5_keyblock_init(smb_krb5_context->krb5_context,
ETYPE_ARCFOUR_HMAC_MD5,
mach_pwd->hash, sizeof(mach_pwd->hash),
&entry.keyblock);
if (ret) {
DEBUG(1, ("create_keytab: krb5_keyblock_init failed: %s\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
return ret;
}
entry.principal = princ;
entry.vno = cli_credentials_get_kvno(machine_account);
ret = krb5_kt_add_entry(smb_krb5_context->krb5_context, keytab, &entry);
if (ret) {
DEBUG(1, ("Failed to add ARCFOUR_HMAC (only) entry for %s to keytab: %s",
cli_credentials_get_principal(machine_account, mem_ctx),
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &entry.keyblock);
return ret;
}
DEBUG(5, ("Added %s(kvno %d) to keytab (arcfour-hmac-md5)\n",
cli_credentials_get_principal(machine_account, mem_ctx),
cli_credentials_get_kvno(machine_account)));
krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &entry.keyblock);
/* Can't go any further, we only have this one key */
talloc_free(mem_ctx);
return 0;
}
kvno = cli_credentials_get_kvno(machine_account);
/* good, we actually have the real plaintext */
ret = keytab_add_keys(mem_ctx, princ_string, princ, salt_princ,
kvno, password_s, smb_krb5_context,
enctype_strings, keytab);
if (!ret) {
talloc_free(mem_ctx);
return ret;
}
if (!add_old || kvno == 0) {
talloc_free(mem_ctx);
return 0;
}
old_secret = cli_credentials_get_old_password(machine_account);
if (!old_secret) {
talloc_free(mem_ctx);
return 0;
}
ret = keytab_add_keys(mem_ctx, princ_string, princ, salt_princ,
kvno - 1, old_secret, smb_krb5_context,
enctype_strings, keytab);
if (!ret) {
talloc_free(mem_ctx);
return ret;
}
talloc_free(mem_ctx);
return 0;
}
static krb5_error_code remove_old_entries(TALLOC_CTX *parent_ctx,
struct cli_credentials *machine_account,
struct smb_krb5_context *smb_krb5_context,
krb5_keytab keytab, BOOL *found_previous)
{
krb5_error_code ret, ret2;
krb5_kt_cursor cursor;
krb5_principal princ;
int kvno;
TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);
const char *princ_string;
if (!mem_ctx) {
return ENOMEM;
}
*found_previous = False;
princ_string = cli_credentials_get_principal(machine_account, mem_ctx);
/* Get the principal we will store the new keytab entries under */
ret = principal_from_credentials(mem_ctx, machine_account, smb_krb5_context, &princ);
if (ret) {
DEBUG(1,("update_keytab: makeing krb5 principal failed (%s)\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
return ret;
}
kvno = cli_credentials_get_kvno(machine_account);
/* for each entry in the keytab */
ret = krb5_kt_start_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);
switch (ret) {
case 0:
break;
case HEIM_ERR_OPNOTSUPP:
case ENOENT:
case KRB5_KT_END:
/* no point enumerating if there isn't anything here */
talloc_free(mem_ctx);
return 0;
default:
DEBUG(1,("failed to open keytab for read of old entries: %s\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
return ret;
}
while (!ret) {
krb5_keytab_entry entry;
ret = krb5_kt_next_entry(smb_krb5_context->krb5_context, keytab, &entry, &cursor);
if (ret) {
break;
}
/* if it matches our principal */
if (!krb5_kt_compare(smb_krb5_context->krb5_context, &entry, princ, 0, 0)) {
/* Free the entry, it wasn't the one we were looking for anyway */
krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
continue;
}
/* delete it, if it is not kvno -1 */
if (entry.vno != (kvno - 1 )) {
/* Release the enumeration. We are going to
* have to start this from the top again,
* because deletes during enumeration may not
* always be consistant.
*
* Also, the enumeration locks a FILE: keytab
*/
krb5_kt_end_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);
ret = krb5_kt_remove_entry(smb_krb5_context->krb5_context, keytab, &entry);
krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
/* Deleted: Restart from the top */
ret2 = krb5_kt_start_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);
if (ret2) {
krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
DEBUG(1,("failed to restart enumeration of keytab: %s\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
talloc_free(mem_ctx);
return ret2;
}
if (ret) {
break;
}
} else {
*found_previous = True;
}
/* Free the entry, we don't need it any more */
krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
}
krb5_kt_end_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);
switch (ret) {
case 0:
break;
case ENOENT:
case KRB5_KT_END:
ret = 0;
break;
default:
DEBUG(1,("failed in deleting old entries for principal: %s: %s\n",
princ_string,
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx)));
}
talloc_free(mem_ctx);
return ret;
}
NTSTATUS trust_pw_change(struct netlogon_creds_cli_context *context,
struct messaging_context *msg_ctx,
struct dcerpc_binding_handle *b,
const char *domain,
bool force)
{
TALLOC_CTX *frame = talloc_stackframe();
struct trust_pw_change_state *state;
struct cli_credentials *creds = NULL;
const struct samr_Password *current_nt_hash = NULL;
const struct samr_Password *previous_nt_hash = NULL;
enum netr_SchannelType sec_channel_type = SEC_CHAN_NULL;
time_t pass_last_set_time;
uint32_t old_version = 0;
struct pdb_trusted_domain *td = NULL;
struct timeval g_timeout = { 0, };
int timeout = 0;
struct timeval tv = { 0, };
size_t new_len = DEFAULT_TRUST_ACCOUNT_PASSWORD_LENGTH;
uint8_t new_password_buffer[256 * 2] = { 0, };
char *new_trust_passwd = NULL;
size_t len = 0;
uint32_t new_version = 0;
uint32_t *new_trust_version = NULL;
NTSTATUS status;
bool ok;
state = talloc_zero(frame, struct trust_pw_change_state);
if (state == NULL) {
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
state->g_ctx = g_lock_ctx_init(state, msg_ctx);
if (state->g_ctx == NULL) {
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
state->g_lock_key = talloc_asprintf(state,
"trust_password_change_%s",
domain);
if (state->g_lock_key == NULL) {
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
g_timeout = timeval_current_ofs(10, 0);
status = g_lock_lock(state->g_ctx,
state->g_lock_key,
G_LOCK_WRITE, g_timeout);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("could not get g_lock on [%s]!\n",
state->g_lock_key));
TALLOC_FREE(frame);
return status;
}
talloc_set_destructor(state, trust_pw_change_state_destructor);
status = pdb_get_trust_credentials(domain, NULL, frame, &creds);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0, ("could not fetch domain creds for domain %s - %s!\n",
domain, nt_errstr(status)));
TALLOC_FREE(frame);
return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
}
current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
if (current_nt_hash == NULL) {
DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
domain));
TALLOC_FREE(frame);
return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
}
old_version = cli_credentials_get_kvno(creds);
pass_last_set_time = cli_credentials_get_password_last_changed_time(creds);
sec_channel_type = cli_credentials_get_secure_channel_type(creds);
new_version = old_version + 1;
switch (sec_channel_type) {
case SEC_CHAN_WKSTA:
case SEC_CHAN_BDC:
break;
case SEC_CHAN_DNS_DOMAIN:
/*
* new_len * 2 = 498 bytes is the largest possible length
* NL_PASSWORD_VERSION consumes the rest of the possible 512 bytes
* and a confounder with at least 2 bytes is required.
*
* Windows uses new_len = 120 => 240 bytes.
*/
new_len = 120;
/* fall through */
case SEC_CHAN_DOMAIN:
status = pdb_get_trusted_domain(frame, domain, &td);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0, ("pdb_get_trusted_domain() failed for domain %s - %s!\n",
domain, nt_errstr(status)));
TALLOC_FREE(frame);
return status;
}
new_trust_version = &new_version;
break;
default:
TALLOC_FREE(frame);
return NT_STATUS_NOT_SUPPORTED;
}
timeout = lp_machine_password_timeout();
if (timeout == 0) {
if (!force) {
DEBUG(10,("machine password never expires\n"));
TALLOC_FREE(frame);
return NT_STATUS_OK;
}
}
tv.tv_sec = pass_last_set_time;
DEBUG(10, ("password last changed %s\n",
timeval_string(talloc_tos(), &tv, false)));
tv.tv_sec += timeout;
DEBUGADD(10, ("password valid until %s\n",
timeval_string(talloc_tos(), &tv, false)));
if (!force && !timeval_expired(&tv)) {
TALLOC_FREE(frame);
return NT_STATUS_OK;
}
/*
* Create a random machine account password
* We create a random buffer and convert that to utf8.
* This is similar to what windows is doing.
*/
generate_secret_buffer(new_password_buffer, new_len * 2);
ok = convert_string_talloc(frame,
CH_UTF16MUNGED, CH_UTF8,
new_password_buffer, new_len * 2,
(void *)&new_trust_passwd, &len);
ZERO_STRUCT(new_password_buffer);
if (!ok) {
DEBUG(0, ("convert_string_talloc failed\n"));
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
/*
* We could use cli_credentials_get_old_nt_hash(creds, frame) to
* set previous_nt_hash.
*
* But we want to check if the dc has our current password and only do
* a change if that's the case. So we keep previous_nt_hash = NULL.
*
* TODO:
* If the previous password is the only password in common with the dc,
* we better skip the password change, or use something like
* ServerTrustPasswordsGet() or netr_ServerGetTrustInfo() to fix our
* local secrets before doing the change.
*/
status = netlogon_creds_cli_auth(context, b,
*current_nt_hash,
previous_nt_hash);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0, ("netlogon_creds_cli_auth for domain %s - %s!\n",
domain, nt_errstr(status)));
TALLOC_FREE(frame);
return status;
}
/*
* Return the result of trying to write the new password
* back into the trust account file.
*/
switch (sec_channel_type) {
case SEC_CHAN_WKSTA:
case SEC_CHAN_BDC:
ok = secrets_store_machine_password(new_trust_passwd, domain, sec_channel_type);
if (!ok) {
DEBUG(0, ("secrets_store_machine_password failed for domain %s!\n",
domain));
TALLOC_FREE(frame);
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
break;
case SEC_CHAN_DNS_DOMAIN:
case SEC_CHAN_DOMAIN:
/*
* we need to get the sid first for the
* pdb_set_trusteddom_pw call
*/
ok = pdb_set_trusteddom_pw(domain, new_trust_passwd,
&td->security_identifier);
if (!ok) {
DEBUG(0, ("pdb_set_trusteddom_pw() failed for domain %s!\n",
domain));
TALLOC_FREE(frame);
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
break;
default:
smb_panic("Unsupported secure channel type");
break;
}
DEBUG(1,("%s : %s(%s): Changed password locally\n",
current_timestring(talloc_tos(), false), __func__, domain));
status = netlogon_creds_cli_ServerPasswordSet(context, b,
new_trust_passwd,
new_trust_version);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0,("%s : %s(%s) remote password change set failed - %s\n",
current_timestring(talloc_tos(), false), __func__,
domain, nt_errstr(status)));
TALLOC_FREE(frame);
return status;
}
DEBUG(1,("%s : %s(%s): Changed password remotely.\n",
current_timestring(talloc_tos(), false), __func__, domain));
TALLOC_FREE(frame);
return NT_STATUS_OK;
}
