int buffer_next_uint16(xrtp_buffer_t * buf, uint16 * ret){
if(buf->pos + sizeof(uint16) > buf->len){
return 0;
}
if(HOST_BYTEORDER == BIGEND_ORDER)
{
*ret = RSVAL(buf->data, buf->pos);
buffer_log(("buffer_next_uint16: BE(%u) at buf[%d]@%d\n", *ret, buf->pos, (int)(buf->data)));
}
else
{
*ret = SVAL(buf->data, buf->pos);
buffer_log(("buffer_next_uint16: LE(%u) at buf[%d]@%d\n", *ret, buf->pos, (int)(buf->data)));
}
if(HOST_BYTEORDER != buf->byte_order)
{
_buffer_swap16(*ret);
buffer_log(("buffer_next_uint16: HE(%u) at buf[%d]@%d\n", *ret, buf->pos, (int)(buf->data)));
}
buf->pos += sizeof(uint16);
return sizeof(uint16);
}
static void dbg_rw_punival(BOOL charmode, const char *name, int depth, prs_struct *ps,
char *in_buf, char *out_buf, int len)
{
int i;
if (UNMARSHALLING(ps)) {
if (ps->bigendian_data) {
for (i = 0; i < len; i++)
SSVAL(out_buf,2*i,RSVAL(in_buf, 2*i));
} else {
for (i = 0; i < len; i++)
SSVAL(out_buf, 2*i, SVAL(in_buf, 2*i));
}
} else {
if (ps->bigendian_data) {
for (i = 0; i < len; i++)
RSSVAL(in_buf, 2*i, SVAL(out_buf,2*i));
} else {
for (i = 0; i < len; i++)
SSVAL(in_buf, 2*i, SVAL(out_buf,2*i));
}
}
DEBUG(5,("%s%04x %s: ", tab_depth(depth), ps->data_offset, name));
if (charmode)
print_asc(5, (unsigned char*)out_buf, 2*len);
else {
for (i = 0; i < len; i++)
DEBUG(5,("%04x ", out_buf[i]));
}
DEBUG(5,("\n"));
}
uint16_t dcerpc_get_frag_length(const DATA_BLOB *blob)
{
if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
return SVAL(blob->data, DCERPC_FRAG_LEN_OFFSET);
} else {
return RSVAL(blob->data, DCERPC_FRAG_LEN_OFFSET);
}
}
_PUBLIC_ NTSTATUS packet_full_request_u16(void *private_data, DATA_BLOB blob, size_t *size)
{
if (blob.length < 2) {
return STATUS_MORE_ENTRIES;
}
*size = 2 + RSVAL(blob.data, 0);
if (*size > blob.length) {
return STATUS_MORE_ENTRIES;
}
return NT_STATUS_OK;
}
BOOL prs_uint16s(BOOL charmode, const char *name, prs_struct *ps, int depth, uint16 *data16s, int len)
{
int i;
char *q = prs_mem_get(ps, len * sizeof(uint16));
if (q == NULL)
return False;
if (UNMARSHALLING(ps)) {
if (ps->bigendian_data) {
for (i = 0; i < len; i++)
data16s[i] = RSVAL(q, 2*i);
} else {
for (i = 0; i < len; i++)
data16s[i] = SVAL(q, 2*i);
}
} else {
if (ps->bigendian_data) {
for (i = 0; i < len; i++)
RSSVAL(q, 2*i, data16s[i]);
} else {
for (i = 0; i < len; i++)
SSVAL(q, 2*i, data16s[i]);
}
}
DEBUG(5,("%s%04x %s: ", tab_depth(depth), ps->data_offset, name));
if (charmode)
print_asc(5, (unsigned char*)data16s, 2*len);
else {
for (i = 0; i < len; i++)
DEBUG(5,("%04x ", data16s[i]));
}
DEBUG(5,("\n"));
ps->data_offset += (len * sizeof(uint16));
return True;
}
BOOL prs_uint16(const char *name, prs_struct *ps, int depth, uint16 *data16)
{
char *q = prs_mem_get(ps, sizeof(uint16));
if (q == NULL)
return False;
if (UNMARSHALLING(ps)) {
if (ps->bigendian_data)
*data16 = RSVAL(q,0);
else
*data16 = SVAL(q,0);
} else {
if (ps->bigendian_data)
RSSVAL(q,0,*data16);
else
SSVAL(q,0,*data16);
}
DEBUG(5,("%s%04x %s: %04x\n", tab_depth(depth), ps->data_offset, name, *data16));
ps->data_offset += sizeof(uint16);
return True;
}
static krb5_error_code parse_setpw_reply(krb5_context context,
bool use_tcp,
krb5_auth_context auth_context,
krb5_data *packet)
{
krb5_data ap_rep;
char *p;
int vnum, ret, res_code;
krb5_data cipherresult;
krb5_data clearresult;
krb5_ap_rep_enc_part *ap_rep_enc;
krb5_replay_data replay;
unsigned int msg_length = packet->length;
if (packet->length < (use_tcp ? 8 : 4)) {
return KRB5KRB_AP_ERR_MODIFIED;
}
p = (char *)packet->data;
/*
** see if it is an error
*/
if (krb5_is_krb_error(packet)) {
ret = handle_krberror_packet(context, packet);
if (ret) {
return ret;
}
}
/* tcp... */
if (use_tcp) {
msg_length -= 4;
if (RIVAL(p, 0) != msg_length) {
DEBUG(1,("Bad TCP packet length (%d/%d) from kpasswd server\n",
RIVAL(p, 0), msg_length));
return KRB5KRB_AP_ERR_MODIFIED;
}
p += 4;
}
if (RSVAL(p, 0) != msg_length) {
DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
RSVAL(p, 0), msg_length));
return KRB5KRB_AP_ERR_MODIFIED;
}
p += 2;
vnum = RSVAL(p, 0); p += 2;
/* FIXME: According to standard there is only one type of reply */
if (vnum != KRB5_KPASSWD_VERS_SETPW &&
vnum != KRB5_KPASSWD_VERS_SETPW_ALT &&
vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
return KRB5KDC_ERR_BAD_PVNO;
}
ap_rep.length = RSVAL(p, 0); p += 2;
if (p + ap_rep.length >= (char *)packet->data + packet->length) {
DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
return KRB5KRB_AP_ERR_MODIFIED;
}
if (ap_rep.length == 0) {
DEBUG(1,("got unencrypted setpw result?!\n"));
return KRB5KRB_AP_ERR_MODIFIED;
}
/* verify ap_rep */
ap_rep.data = p;
p += ap_rep.length;
ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
if (ret) {
DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
return KRB5KRB_AP_ERR_MODIFIED;
}
krb5_free_ap_rep_enc_part(context, ap_rep_enc);
cipherresult.data = p;
cipherresult.length = ((char *)packet->data + packet->length) - p;
ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
&replay);
if (ret) {
DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
return KRB5KRB_AP_ERR_MODIFIED;
}
if (clearresult.length < 2) {
free(clearresult.data);
ret = KRB5KRB_AP_ERR_MODIFIED;
return KRB5KRB_AP_ERR_MODIFIED;
}
p = (char *)clearresult.data;
res_code = RSVAL(p, 0);
free(clearresult.data);
if ((res_code < KRB5_KPASSWD_SUCCESS) ||
(res_code > KRB5_KPASSWD_ETYPE_NOSUPP)) {
return KRB5KRB_AP_ERR_MODIFIED;
}
if (res_code == KRB5_KPASSWD_SUCCESS) {
return 0;
} else {
const char *errstr;
setpw_result_code_string(context, res_code, &errstr);
DEBUG(1, ("Error changing password: %s (%d)\n", errstr, res_code));
return kpasswd_err_to_krb5_err(res_code);
}
}
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;
}
WERROR dns_verify_tsig(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
struct dns_request_state *state,
struct dns_name_packet *packet,
DATA_BLOB *in)
{
WERROR werror;
NTSTATUS status;
enum ndr_err_code ndr_err;
bool found_tsig = false;
uint16_t i, arcount = 0;
DATA_BLOB tsig_blob, fake_tsig_blob, sig;
uint8_t *buffer = NULL;
size_t buffer_len = 0, packet_len = 0;
struct dns_server_tkey *tkey = NULL;
struct dns_fake_tsig_rec *check_rec = talloc_zero(mem_ctx,
struct dns_fake_tsig_rec);
/* Find the first TSIG record in the additional records */
for (i=0; i < packet->arcount; i++) {
if (packet->additional[i].rr_type == DNS_QTYPE_TSIG) {
found_tsig = true;
break;
}
}
if (!found_tsig) {
return WERR_OK;
}
/* The TSIG record needs to be the last additional record */
if (found_tsig && i + 1 != packet->arcount) {
DEBUG(1, ("TSIG record not the last additional record!\n"));
return DNS_ERR(FORMAT_ERROR);
}
/* We got a TSIG, so we need to sign our reply */
state->sign = true;
state->tsig = talloc_zero(state->mem_ctx, struct dns_res_rec);
if (state->tsig == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
werror = dns_copy_tsig(state->tsig, &packet->additional[i],
state->tsig);
if (!W_ERROR_IS_OK(werror)) {
return werror;
}
packet->arcount--;
tkey = dns_find_tkey(dns->tkeys, state->tsig->name);
if (tkey == NULL) {
/*
* We must save the name for use in the TSIG error
* response and have no choice here but to save the
* keyname from the TSIG request.
*/
state->key_name = talloc_strdup(state->mem_ctx,
state->tsig->name);
if (state->key_name == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
state->tsig_error = DNS_RCODE_BADKEY;
return DNS_ERR(NOTAUTH);
}
/*
* Remember the keyname that found an existing tkey, used
* later to fetch the key with dns_find_tkey() when signing
* and adding a TSIG record with MAC.
*/
state->key_name = talloc_strdup(state->mem_ctx, tkey->name);
if (state->key_name == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
/* FIXME: check TSIG here */
if (check_rec == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
/* first build and verify check packet */
check_rec->name = talloc_strdup(check_rec, tkey->name);
if (check_rec->name == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
check_rec->rr_class = DNS_QCLASS_ANY;
check_rec->ttl = 0;
check_rec->algorithm_name = talloc_strdup(check_rec, tkey->algorithm);
if (check_rec->algorithm_name == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
check_rec->time_prefix = 0;
check_rec->time = state->tsig->rdata.tsig_record.time;
check_rec->fudge = state->tsig->rdata.tsig_record.fudge;
check_rec->error = 0;
check_rec->other_size = 0;
check_rec->other_data = NULL;
ndr_err = ndr_push_struct_blob(&tsig_blob, mem_ctx, state->tsig,
(ndr_push_flags_fn_t)ndr_push_dns_res_rec);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DEBUG(1, ("Failed to push packet: %s!\n",
ndr_errstr(ndr_err)));
return DNS_ERR(SERVER_FAILURE);
}
ndr_err = ndr_push_struct_blob(&fake_tsig_blob, mem_ctx, check_rec,
(ndr_push_flags_fn_t)ndr_push_dns_fake_tsig_rec);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DEBUG(1, ("Failed to push packet: %s!\n",
ndr_errstr(ndr_err)));
return DNS_ERR(SERVER_FAILURE);
}
/* we need to work some magic here. we need to keep the input packet
* exactly like we got it, but we need to cut off the tsig record */
packet_len = in->length - tsig_blob.length;
buffer_len = packet_len + fake_tsig_blob.length;
buffer = talloc_zero_array(mem_ctx, uint8_t, buffer_len);
if (buffer == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
memcpy(buffer, in->data, packet_len);
memcpy(buffer + packet_len, fake_tsig_blob.data, fake_tsig_blob.length);
sig.length = state->tsig->rdata.tsig_record.mac_size;
sig.data = talloc_memdup(mem_ctx, state->tsig->rdata.tsig_record.mac, sig.length);
if (sig.data == NULL) {
return WERR_NOT_ENOUGH_MEMORY;
}
/* Now we also need to count down the additional record counter */
arcount = RSVAL(buffer, 10);
RSSVAL(buffer, 10, arcount-1);
status = gensec_check_packet(tkey->gensec, buffer, buffer_len,
buffer, buffer_len, &sig);
if (NT_STATUS_EQUAL(NT_STATUS_ACCESS_DENIED, status)) {
state->tsig_error = DNS_RCODE_BADSIG;
return DNS_ERR(NOTAUTH);
}
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Verifying tsig failed: %s\n", nt_errstr(status)));
return ntstatus_to_werror(status);
}
state->authenticated = true;
return WERR_OK;
}
