void aes_ccm_128_init(struct aes_ccm_128_context *ctx,
const uint8_t K[AES_BLOCK_SIZE],
const uint8_t N[AES_CCM_128_NONCE_SIZE],
size_t a_total, size_t m_total)
{
uint8_t B_0[AES_BLOCK_SIZE];
ZERO_STRUCTP(ctx);
AES_set_encrypt_key(K, 128, &ctx->aes_key);
memcpy(ctx->nonce, N, AES_CCM_128_NONCE_SIZE);
ctx->a_remain = a_total;
ctx->m_remain = m_total;
/*
* prepare B_0
*/
B_0[0] = L_;
B_0[0] += 8 * M_;
if (a_total > 0) {
B_0[0] += 64;
}
memcpy(&B_0[1], ctx->nonce, AES_CCM_128_NONCE_SIZE);
RSIVAL(B_0, (AES_BLOCK_SIZE - AES_CCM_128_L), m_total);
/*
* prepare X_1
*/
AES_encrypt(B_0, ctx->X_i, &ctx->aes_key);
/*
* prepare B_1
*/
if (a_total >= UINT32_MAX) {
RSSVAL(ctx->B_i, 0, 0xFFFF);
RSBVAL(ctx->B_i, 2, (uint64_t)a_total);
ctx->B_i_ofs = 10;
} else if (a_total >= 0xFF00) {
RSSVAL(ctx->B_i, 0, 0xFFFE);
RSIVAL(ctx->B_i, 2, a_total);
ctx->B_i_ofs = 6;
} else if (a_total > 0) {
RSSVAL(ctx->B_i, 0, a_total);
ctx->B_i_ofs = 2;
}
ctx->S_i_ofs = AES_BLOCK_SIZE;
}
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"));
}
void dcerpc_set_auth_length(DATA_BLOB *blob, uint16_t v)
{
if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
SSVAL(blob->data, DCERPC_AUTH_LEN_OFFSET, v);
} else {
RSSVAL(blob->data, DCERPC_AUTH_LEN_OFFSET, v);
}
}
/* this function is due to be replaced */
void initrpcreply(char *inbuf, char *q)
{
uint32 callid;
SCVAL(q, 0, 5); q++; /* RPC version 5 */
SCVAL(q, 0, 0); q++; /* minor version 0 */
SCVAL(q, 0, 2); q++; /* RPC response packet */
SCVAL(q, 0, 3); q++; /* first frag + last frag */
RSIVAL(q, 0, 0x10000000); q += 4; /* packed data representation */
RSSVAL(q, 0, 0); q += 2; /* fragment length, fill in later */
SSVAL(q, 0, 0); q += 2; /* authentication length */
callid = RIVAL(inbuf, 12);
RSIVAL(q, 0, callid); q += 4; /* call identifier - match incoming RPC */
SIVAL(q, 0, 0x18); q += 4; /* allocation hint (no idea) */
SSVAL(q, 0, 0); q += 2; /* presentation context identifier */
SCVAL(q, 0, 0); q++; /* cancel count */
SCVAL(q, 0, 0); q++; /* reserved */
}
/*
send a WACK reply
*/
void nbtd_wack_reply(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *request_packet,
struct socket_address *src,
uint32_t ttl)
{
struct nbt_name_packet *packet;
struct nbt_name *name = &request_packet->questions[0].name;
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct nbtd_server *nbtsrv = iface->nbtsrv;
packet = talloc_zero(nbtsock, struct nbt_name_packet);
if (packet == NULL) return;
packet->name_trn_id = request_packet->name_trn_id;
packet->ancount = 1;
packet->operation =
NBT_FLAG_REPLY |
NBT_OPCODE_WACK |
NBT_FLAG_AUTHORITIVE;
packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
if (packet->answers == NULL) goto failed;
packet->answers[0].name = *name;
packet->answers[0].rr_type = NBT_QTYPE_NETBIOS;
packet->answers[0].rr_class = NBT_QCLASS_IP;
packet->answers[0].ttl = ttl;
packet->answers[0].rdata.data.length = 2;
packet->answers[0].rdata.data.data = talloc_size(packet, 2);
if (packet->answers[0].rdata.data.data == NULL) goto failed;
RSSVAL(packet->answers[0].rdata.data.data, 0, request_packet->operation);
DEBUG(7,("Sending WACK reply for %s to %s:%d\n",
nbt_name_string(packet, name), src->addr, src->port));
nbtsrv->stats.total_sent++;
nbt_name_reply_send(nbtsock, src, packet);
failed:
talloc_free(packet);
}
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;
}
int buffer_add_uint16(xrtp_buffer_t * buf, uint16 word){
if(buf->len_data + sizeof(uint16) > buf->len){
return OS_EREFUSE;
}
if(buf->byte_order == BIGEND_ORDER)
{
buffer_log(("buffer_add_uint16: Add BE(%u) to buf[%d]@%d\n", word, buf->pos, (int)(buf->data)));
RSSVAL(buf->data, buf->len_data, word);
}
else
{
buffer_log(("buffer_add_uint16: Add LE(%u) to buf[%d]@%d\n", word, buf->pos, (int)(buf->data)));
SSVAL(buf->data, buf->len_data, word);
}
buf->len_data += sizeof(uint16);
buf->pos += sizeof(uint16);
return OS_OK;
}
/* Return true if there is a valid error packet formed in the error_blob */
static bool kpasswdd_make_error_reply(struct kdc_server *kdc,
TALLOC_CTX *mem_ctx,
uint16_t result_code,
const char *error_string,
DATA_BLOB *error_blob)
{
char *error_string_utf8;
size_t len;
DEBUG(result_code ? 3 : 10, ("kpasswdd: %s\n", error_string));
if (!push_utf8_talloc(mem_ctx, &error_string_utf8, error_string, &len)) {
return false;
}
*error_blob = data_blob_talloc(mem_ctx, NULL, 2 + len + 1);
if (!error_blob->data) {
return false;
}
RSSVAL(error_blob->data, 0, result_code);
memcpy(error_blob->data + 2, error_string_utf8, len + 1);
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 build_kpasswd_request(uint16 pversion,
krb5_context context,
krb5_auth_context auth_context,
krb5_data *ap_req,
const char *princ,
const char *passwd,
bool use_tcp,
krb5_data *packet)
{
krb5_error_code ret;
krb5_data cipherpw;
krb5_data encoded_setpw;
krb5_replay_data replay;
char *p, *msg_start;
DATA_BLOB setpw;
unsigned int msg_length;
ret = krb5_auth_con_setflags(context,
auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
if (ret) {
DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
error_message(ret)));
return ret;
}
/* handle protocol differences in chpw and setpw */
if (pversion == KRB5_KPASSWD_VERS_CHANGEPW)
setpw = data_blob(passwd, strlen(passwd));
else if (pversion == KRB5_KPASSWD_VERS_SETPW ||
pversion == KRB5_KPASSWD_VERS_SETPW_ALT)
setpw = encode_krb5_setpw(princ, passwd);
else
return EINVAL;
if (setpw.data == NULL || setpw.length == 0) {
return EINVAL;
}
encoded_setpw.data = (char *)setpw.data;
encoded_setpw.length = setpw.length;
ret = krb5_mk_priv(context, auth_context,
&encoded_setpw, &cipherpw, &replay);
data_blob_free(&setpw); /*from 'encode_krb5_setpw(...)' */
if (ret) {
DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
return ret;
}
packet->data = (char *)SMB_MALLOC(ap_req->length + cipherpw.length + (use_tcp ? 10 : 6 ));
if (!packet->data)
return -1;
/* see the RFC for details */
msg_start = p = ((char *)packet->data) + (use_tcp ? 4 : 0);
p += 2;
RSSVAL(p, 0, pversion);
p += 2;
RSSVAL(p, 0, ap_req->length);
p += 2;
memcpy(p, ap_req->data, ap_req->length);
p += ap_req->length;
memcpy(p, cipherpw.data, cipherpw.length);
p += cipherpw.length;
packet->length = PTR_DIFF(p,packet->data);
msg_length = PTR_DIFF(p,msg_start);
if (use_tcp) {
RSIVAL(packet->data, 0, msg_length);
}
RSSVAL(msg_start, 0, msg_length);
free(cipherpw.data); /* from 'krb5_mk_priv(...)' */
return 0;
}
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;
}