static ADS_STATUS ads_sasl_gensec_unwrap(struct ads_saslwrap *wrap)
{
struct gensec_security *gensec_security =
talloc_get_type_abort(wrap->wrap_private_data,
struct gensec_security);
NTSTATUS nt_status;
DATA_BLOB unwrapped, wrapped;
TALLOC_CTX *frame = talloc_stackframe();
wrapped = data_blob_const(wrap->in.buf + 4, wrap->in.ofs - 4);
nt_status = gensec_unwrap(gensec_security, frame, &wrapped, &unwrapped);
if (!NT_STATUS_IS_OK(nt_status)) {
TALLOC_FREE(frame);
return ADS_ERROR_NT(nt_status);
}
if (wrapped.length < unwrapped.length) {
TALLOC_FREE(frame);
return ADS_ERROR_NT(NT_STATUS_INTERNAL_ERROR);
}
/* copy the wrapped blob to the right location */
memcpy(wrap->in.buf + 4, unwrapped.data, unwrapped.length);
/* set how many bytes must be written to the underlying socket */
wrap->in.left = unwrapped.length;
wrap->in.ofs = 4;
TALLOC_FREE(frame);
return ADS_SUCCESS;
}
static NTSTATUS common_gensec_decrypt_buffer(struct gensec_security *gensec,
char *buf)
{
NTSTATUS status;
size_t buf_len = smb_len_nbt(buf) + 4; /* Don't forget the 4 length bytes. */
DATA_BLOB in_buf, out_buf;
TALLOC_CTX *frame;
if (buf_len < 8) {
return NT_STATUS_BUFFER_TOO_SMALL;
}
frame = talloc_stackframe();
in_buf = data_blob_const(buf + 8, buf_len - 8);
status = gensec_unwrap(gensec, frame, &in_buf, &out_buf);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0,("common_gensec_decrypt_buffer: gensec_unwrap failed. Error %s\n",
nt_errstr(status)));
TALLOC_FREE(frame);
return status;
}
if (out_buf.length > in_buf.length) {
DEBUG(0,("common_gensec_decrypt_buffer: gensec_unwrap size (%u) too large (%u) !\n",
(unsigned int)out_buf.length,
(unsigned int)in_buf.length ));
TALLOC_FREE(frame);
return NT_STATUS_INVALID_PARAMETER;
}
memcpy(buf + 8, out_buf.data, out_buf.length);
/* Reset the length and overwrite the header. */
smb_setlen_nbt(buf, out_buf.length + 4);
TALLOC_FREE(frame);
return NT_STATUS_OK;
}
/*
* These functions are for use in the deprecated
* gensec_socket code (public because SPNEGO must
* use them for recursion)
*/
NTSTATUS gensec_unwrap_packets(struct gensec_security *gensec_security,
TALLOC_CTX *mem_ctx,
const DATA_BLOB *in,
DATA_BLOB *out,
size_t *len_processed)
{
if (!gensec_security->ops->unwrap_packets) {
DATA_BLOB wrapped;
NTSTATUS nt_status;
size_t packet_size;
if (in->length < 4) {
/* Missing the header we already had! */
DEBUG(0, ("Asked to unwrap packet of bogus length! How did we get the short packet?!\n"));
return NT_STATUS_INVALID_PARAMETER;
}
packet_size = RIVAL(in->data, 0);
wrapped = data_blob_const(in->data + 4, packet_size);
if (wrapped.length > (in->length - 4)) {
DEBUG(0, ("Asked to unwrap packed of bogus length %d > %d! How did we get this?!\n",
(int)wrapped.length, (int)(in->length - 4)));
return NT_STATUS_INTERNAL_ERROR;
}
nt_status = gensec_unwrap(gensec_security,
mem_ctx,
&wrapped, out);
if (!NT_STATUS_IS_OK(nt_status)) {
return nt_status;
}
*len_processed = packet_size + 4;
return nt_status;
}
return gensec_security->ops->unwrap_packets(gensec_security, mem_ctx, in, out,
len_processed);
}
bool kpasswdd_process(struct kdc_server *kdc,
TALLOC_CTX *mem_ctx,
DATA_BLOB *input,
DATA_BLOB *reply,
struct tsocket_address *peer_addr,
struct tsocket_address *my_addr,
int datagram_reply)
{
bool ret;
const uint16_t header_len = 6;
uint16_t len;
uint16_t ap_req_len;
uint16_t krb_priv_len;
uint16_t version;
NTSTATUS nt_status;
DATA_BLOB ap_req, krb_priv_req;
DATA_BLOB krb_priv_rep = data_blob(NULL, 0);
DATA_BLOB ap_rep = data_blob(NULL, 0);
DATA_BLOB kpasswd_req, kpasswd_rep;
struct cli_credentials *server_credentials;
struct gensec_security *gensec_security;
TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
char *keytab_name;
if (!tmp_ctx) {
return false;
}
/* Be parinoid. We need to ensure we don't just let the
* caller lead us into a buffer overflow */
if (input->length <= header_len) {
talloc_free(tmp_ctx);
return false;
}
len = RSVAL(input->data, 0);
if (input->length != len) {
talloc_free(tmp_ctx);
return false;
}
/* There are two different versions of this protocol so far,
* plus others in the standards pipe. Fortunetly they all
* take a very similar framing */
version = RSVAL(input->data, 2);
ap_req_len = RSVAL(input->data, 4);
if ((ap_req_len >= len) || (ap_req_len + header_len) >= len) {
talloc_free(tmp_ctx);
return false;
}
krb_priv_len = len - ap_req_len;
ap_req = data_blob_const(&input->data[header_len], ap_req_len);
krb_priv_req = data_blob_const(&input->data[header_len + ap_req_len], krb_priv_len);
server_credentials = cli_credentials_init(tmp_ctx);
if (!server_credentials) {
DEBUG(1, ("Failed to init server credentials\n"));
return false;
}
/* We want the credentials subsystem to use the krb5 context
* we already have, rather than a new context */
cli_credentials_set_krb5_context(server_credentials, kdc->smb_krb5_context);
cli_credentials_set_conf(server_credentials, kdc->task->lp_ctx);
keytab_name = talloc_asprintf(server_credentials, "HDB:samba4&%p", kdc->base_ctx);
cli_credentials_set_username(server_credentials, "kadmin/changepw", CRED_SPECIFIED);
ret = cli_credentials_set_keytab_name(server_credentials, kdc->task->event_ctx, kdc->task->lp_ctx, keytab_name, CRED_SPECIFIED);
if (ret != 0) {
ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
KRB5_KPASSWD_HARDERROR,
talloc_asprintf(mem_ctx,
"Failed to obtain server credentials for kadmin/changepw: %s\n",
nt_errstr(nt_status)),
&krb_priv_rep);
ap_rep.length = 0;
if (ret) {
goto reply;
}
talloc_free(tmp_ctx);
return ret;
}
/* We don't strictly need to call this wrapper, and could call
* gensec_server_start directly, as we have no need for NTLM
* and we have a PAC, but this ensures that the wrapper can be
* safely extended for other helpful things in future */
nt_status = samba_server_gensec_start(tmp_ctx, kdc->task->event_ctx,
kdc->task->msg_ctx,
kdc->task->lp_ctx,
server_credentials,
"kpasswd",
&gensec_security);
if (!NT_STATUS_IS_OK(nt_status)) {
talloc_free(tmp_ctx);
return false;
}
/* The kerberos PRIV packets include these addresses. MIT
* clients check that they are present */
#if 0
/* Skip this part for now, it breaks with a NetAPP filer and
* in any case where the client address is behind NAT. If
* older MIT clients need this, we might have to insert more
* complex code */
nt_status = gensec_set_local_address(gensec_security, peer_addr);
if (!NT_STATUS_IS_OK(nt_status)) {
talloc_free(tmp_ctx);
return false;
}
#endif
nt_status = gensec_set_local_address(gensec_security, my_addr);
if (!NT_STATUS_IS_OK(nt_status)) {
talloc_free(tmp_ctx);
return false;
}
/* We want the GENSEC wrap calls to generate PRIV tokens */
gensec_want_feature(gensec_security, GENSEC_FEATURE_SEAL);
nt_status = gensec_start_mech_by_name(gensec_security, "krb5");
if (!NT_STATUS_IS_OK(nt_status)) {
talloc_free(tmp_ctx);
return false;
}
/* Accept the AP-REQ and generate teh AP-REP we need for the reply */
nt_status = gensec_update(gensec_security, tmp_ctx, ap_req, &ap_rep);
if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
KRB5_KPASSWD_HARDERROR,
talloc_asprintf(mem_ctx,
"gensec_update failed: %s",
nt_errstr(nt_status)),
&krb_priv_rep);
ap_rep.length = 0;
if (ret) {
goto reply;
}
talloc_free(tmp_ctx);
return ret;
}
/* Extract the data from the KRB-PRIV half of the message */
nt_status = gensec_unwrap(gensec_security, tmp_ctx, &krb_priv_req, &kpasswd_req);
if (!NT_STATUS_IS_OK(nt_status)) {
ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
KRB5_KPASSWD_HARDERROR,
talloc_asprintf(mem_ctx,
"gensec_unwrap failed: %s",
nt_errstr(nt_status)),
&krb_priv_rep);
ap_rep.length = 0;
if (ret) {
goto reply;
}
talloc_free(tmp_ctx);
return ret;
}
/* Figure out something to do with it (probably changing a password...) */
ret = kpasswd_process_request(kdc, tmp_ctx,
gensec_security,
version,
&kpasswd_req, &kpasswd_rep);
if (!ret) {
/* Argh! */
return false;
}
/* And wrap up the reply: This ensures that the error message
* or success can be verified by the client */
nt_status = gensec_wrap(gensec_security, tmp_ctx,
&kpasswd_rep, &krb_priv_rep);
if (!NT_STATUS_IS_OK(nt_status)) {
ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
KRB5_KPASSWD_HARDERROR,
talloc_asprintf(mem_ctx,
"gensec_wrap failed: %s",
nt_errstr(nt_status)),
&krb_priv_rep);
ap_rep.length = 0;
if (ret) {
goto reply;
}
talloc_free(tmp_ctx);
return ret;
}
reply:
*reply = data_blob_talloc(mem_ctx, NULL, krb_priv_rep.length + ap_rep.length + header_len);
if (!reply->data) {
return false;
}
RSSVAL(reply->data, 0, reply->length);
RSSVAL(reply->data, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
RSSVAL(reply->data, 4, ap_rep.length);
memcpy(reply->data + header_len,
ap_rep.data,
ap_rep.length);
memcpy(reply->data + header_len + ap_rep.length,
krb_priv_rep.data,
krb_priv_rep.length);
talloc_free(tmp_ctx);
return ret;
}
