/*
parse a negTokenInit packet giving a GUID, a list of supported
OIDs (the mechanisms) and a principal name string
*/
bool spnego_parse_negTokenInit(TALLOC_CTX *ctx,
DATA_BLOB blob,
char *OIDs[ASN1_MAX_OIDS],
char **principal,
DATA_BLOB *secblob)
{
int i;
bool ret = false;
ASN1_DATA *data;
for (i = 0; i < ASN1_MAX_OIDS; i++) {
OIDs[i] = NULL;
}
if (principal) {
*principal = NULL;
}
if (secblob) {
*secblob = data_blob_null;
}
data = asn1_init(talloc_tos());
if (data == NULL) {
return false;
}
if (!asn1_load(data, blob)) goto err;
if (!asn1_start_tag(data,ASN1_APPLICATION(0))) goto err;
if (!asn1_check_OID(data,OID_SPNEGO)) goto err;
/* negTokenInit [0] NegTokenInit */
if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
/* mechTypes [0] MechTypeList OPTIONAL */
/* Not really optional, we depend on this to decide
* what mechanisms we have to work with. */
if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
if (!asn1_read_OID(data,ctx, &OIDs[i])) {
goto err;
}
if (asn1_has_error(data)) {
goto err;
}
}
OIDs[i] = NULL;
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
/*
Win7 + Live Sign-in Assistant attaches a mechToken
ASN1_CONTEXT(2) to the negTokenInit packet
which breaks our negotiation if we just assume
the next tag is ASN1_CONTEXT(3).
*/
if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
uint8_t flags;
/* reqFlags [1] ContextFlags OPTIONAL */
if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
if (!asn1_start_tag(data, ASN1_BIT_STRING)) goto err;
while (asn1_tag_remaining(data) > 0) {
if (!asn1_read_uint8(data, &flags)) goto err;
}
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
}
if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
DATA_BLOB sblob = data_blob_null;
/* mechToken [2] OCTET STRING OPTIONAL */
if (!asn1_start_tag(data, ASN1_CONTEXT(2))) goto err;
if (!asn1_read_OctetString(data, ctx, &sblob)) goto err;
if (!asn1_end_tag(data)) {
data_blob_free(&sblob);
goto err;
}
if (secblob) {
*secblob = sblob;
} else {
data_blob_free(&sblob);
}
}
if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
char *princ = NULL;
/* mechListMIC [3] OCTET STRING OPTIONAL */
if (!asn1_start_tag(data, ASN1_CONTEXT(3))) goto err;
if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
if (!asn1_start_tag(data, ASN1_CONTEXT(0))) goto err;
if (!asn1_read_GeneralString(data, ctx, &princ)) goto err;
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
if (principal) {
*principal = princ;
} else {
TALLOC_FREE(princ);
}
}
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
ret = !asn1_has_error(data);
err:
if (asn1_has_error(data)) {
int j;
if (principal) {
TALLOC_FREE(*principal);
}
if (secblob) {
data_blob_free(secblob);
}
for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
TALLOC_FREE(OIDs[j]);
}
}
asn1_free(data);
return ret;
}
/*
parse a SPNEGO auth packet. This contains the encrypted passwords
*/
bool spnego_parse_auth_response(TALLOC_CTX *ctx,
DATA_BLOB blob, NTSTATUS nt_status,
const char *mechOID,
DATA_BLOB *auth)
{
ASN1_DATA *data;
uint8 negResult;
bool ret = false;
if (NT_STATUS_IS_OK(nt_status)) {
negResult = SPNEGO_ACCEPT_COMPLETED;
} else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
negResult = SPNEGO_ACCEPT_INCOMPLETE;
} else {
negResult = SPNEGO_REJECT;
}
data = asn1_init(talloc_tos());
if (data == NULL) {
return false;
}
*auth = data_blob_null;
if (!asn1_load(data, blob)) goto err;
if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
if (!asn1_start_tag(data, ASN1_CONTEXT(0))) goto err;
if (!asn1_check_enumerated(data, negResult)) goto err;
if (!asn1_end_tag(data)) goto err;
if (asn1_tag_remaining(data)) {
if (!asn1_start_tag(data,ASN1_CONTEXT(1))) goto err;
if (!asn1_check_OID(data, mechOID)) goto err;
if (!asn1_end_tag(data)) goto err;
if (asn1_tag_remaining(data)) {
if (!asn1_start_tag(data,ASN1_CONTEXT(2))) goto err;
if (!asn1_read_OctetString(data, ctx, auth)) goto err;
if (!asn1_end_tag(data)) goto err;
}
} else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
data->has_error = 1;
goto err;
}
/* Binding against Win2K DC returns a duplicate of the responseToken in
* the optional mechListMIC field. This is a bug in Win2K. We ignore
* this field if it exists. Win2K8 may return a proper mechListMIC at
* which point we need to implement the integrity checking. */
if (asn1_tag_remaining(data)) {
DATA_BLOB mechList = data_blob_null;
if (!asn1_start_tag(data, ASN1_CONTEXT(3))) goto err;
if (!asn1_read_OctetString(data, ctx, &mechList)) goto err;
data_blob_free(&mechList);
if (!asn1_end_tag(data)) goto err;
DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
"ignoring.\n"));
}
if (!asn1_end_tag(data)) goto err;
if (!asn1_end_tag(data)) goto err;
ret = !data->has_error;
err:
if (data->has_error) {
DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
asn1_free(data);
data_blob_free(auth);
return false;
}
asn1_free(data);
return ret;
}
/* This implements kerberos password change protocol as specified in
* kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
* as well as microsoft version of the protocol
* as specified in kerberos-set-passwd-00.txt
*/
static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
{
char* princ_part1 = NULL;
char* princ_part2 = NULL;
char* realm = NULL;
char* c;
char* princ;
ASN1_DATA req;
DATA_BLOB ret;
princ = SMB_STRDUP(principal);
if ((c = strchr_m(princ, '/')) == NULL) {
c = princ;
} else {
*c = '\0';
c++;
princ_part1 = princ;
}
princ_part2 = c;
if ((c = strchr_m(c, '@')) != NULL) {
*c = '\0';
c++;
realm = c;
} else {
/* We must have a realm component. */
return data_blob_null;
}
memset(&req, 0, sizeof(req));
asn1_push_tag(&req, ASN1_SEQUENCE(0));
asn1_push_tag(&req, ASN1_CONTEXT(0));
asn1_write_OctetString(&req, password, strlen(password));
asn1_pop_tag(&req);
asn1_push_tag(&req, ASN1_CONTEXT(1));
asn1_push_tag(&req, ASN1_SEQUENCE(0));
asn1_push_tag(&req, ASN1_CONTEXT(0));
asn1_write_Integer(&req, 1);
asn1_pop_tag(&req);
asn1_push_tag(&req, ASN1_CONTEXT(1));
asn1_push_tag(&req, ASN1_SEQUENCE(0));
if (princ_part1) {
asn1_write_GeneralString(&req, princ_part1);
}
asn1_write_GeneralString(&req, princ_part2);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
asn1_push_tag(&req, ASN1_CONTEXT(2));
asn1_write_GeneralString(&req, realm);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
ret = data_blob(req.data, req.length);
asn1_free(&req);
free(princ);
return ret;
}
DATA_BLOB spnego_gen_negTokenInit(TALLOC_CTX *ctx,
const char *OIDs[],
DATA_BLOB *psecblob,
const char *principal)
{
int i;
ASN1_DATA *data;
DATA_BLOB ret = data_blob_null;
data = asn1_init(talloc_tos());
if (data == NULL) {
return data_blob_null;
}
if (!asn1_push_tag(data,ASN1_APPLICATION(0))) goto err;
if (!asn1_write_OID(data,OID_SPNEGO)) goto err;
if (!asn1_push_tag(data,ASN1_CONTEXT(0))) goto err;
if (!asn1_push_tag(data,ASN1_SEQUENCE(0))) goto err;
if (!asn1_push_tag(data,ASN1_CONTEXT(0))) goto err;
if (!asn1_push_tag(data,ASN1_SEQUENCE(0))) goto err;
for (i=0; OIDs[i]; i++) {
if (!asn1_write_OID(data,OIDs[i])) goto err;
}
if (!asn1_pop_tag(data)) goto err;
if (!asn1_pop_tag(data)) goto err;
if (psecblob && psecblob->length && psecblob->data) {
if (!asn1_push_tag(data, ASN1_CONTEXT(2))) goto err;
if (!asn1_write_OctetString(data,psecblob->data,
psecblob->length)) goto err;
if (!asn1_pop_tag(data)) goto err;
}
if (principal) {
if (!asn1_push_tag(data, ASN1_CONTEXT(3))) goto err;
if (!asn1_push_tag(data, ASN1_SEQUENCE(0))) goto err;
if (!asn1_push_tag(data, ASN1_CONTEXT(0))) goto err;
if (!asn1_write_GeneralString(data,principal)) goto err;
if (!asn1_pop_tag(data)) goto err;
if (!asn1_pop_tag(data)) goto err;
if (!asn1_pop_tag(data)) goto err;
}
if (!asn1_pop_tag(data)) goto err;
if (!asn1_pop_tag(data)) goto err;
if (!asn1_pop_tag(data)) goto err;
ret = data_blob_talloc(ctx, data->data, data->length);
err:
if (data->has_error) {
DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
}
asn1_free(data);
return ret;
}
static NTSTATUS check_spnego_blob_complete(uint16 smbpid, uint16 vuid, DATA_BLOB *pblob)
{
struct pending_auth_data *pad = NULL;
ASN1_DATA data;
size_t needed_len = 0;
pad = get_pending_auth_data(smbpid);
/* Ensure we have some data. */
if (pblob->length == 0) {
/* Caller can cope. */
DEBUG(2,("check_spnego_blob_complete: zero blob length !\n"));
delete_partial_auth(pad);
return NT_STATUS_OK;
}
/* Were we waiting for more data ? */
if (pad) {
DATA_BLOB tmp_blob;
size_t copy_len = MIN(65536, pblob->length);
/* Integer wrap paranoia.... */
if (pad->partial_data.length + copy_len < pad->partial_data.length ||
pad->partial_data.length + copy_len < copy_len) {
DEBUG(2,("check_spnego_blob_complete: integer wrap "
"pad->partial_data.length = %u, "
"copy_len = %u\n",
(unsigned int)pad->partial_data.length,
(unsigned int)copy_len ));
delete_partial_auth(pad);
return NT_STATUS_INVALID_PARAMETER;
}
DEBUG(10,("check_spnego_blob_complete: "
"pad->partial_data.length = %u, "
"pad->needed_len = %u, "
"copy_len = %u, "
"pblob->length = %u,\n",
(unsigned int)pad->partial_data.length,
(unsigned int)pad->needed_len,
(unsigned int)copy_len,
(unsigned int)pblob->length ));
tmp_blob = data_blob(NULL,
pad->partial_data.length + copy_len);
/* Concatenate the two (up to copy_len) bytes. */
memcpy(tmp_blob.data,
pad->partial_data.data,
pad->partial_data.length);
memcpy(tmp_blob.data + pad->partial_data.length,
pblob->data,
copy_len);
/* Replace the partial data. */
data_blob_free(&pad->partial_data);
pad->partial_data = tmp_blob;
ZERO_STRUCT(tmp_blob);
/* Are we done ? */
if (pblob->length >= pad->needed_len) {
/* Yes, replace pblob. */
data_blob_free(pblob);
*pblob = pad->partial_data;
ZERO_STRUCT(pad->partial_data);
delete_partial_auth(pad);
return NT_STATUS_OK;
}
/* Still need more data. */
pad->needed_len -= copy_len;
return NT_STATUS_MORE_PROCESSING_REQUIRED;
}
if ((pblob->data[0] != ASN1_APPLICATION(0)) &&
(pblob->data[0] != ASN1_CONTEXT(1))) {
/* Not something we can determine the
* length of.
*/
return NT_STATUS_OK;
}
/* This is a new SPNEGO sessionsetup - see if
* the data given in this blob is enough.
*/
asn1_load(&data, *pblob);
asn1_start_tag(&data, pblob->data[0]);
if (data.has_error || data.nesting == NULL) {
asn1_free(&data);
/* Let caller catch. */
return NT_STATUS_OK;
}
/* Integer wrap paranoia.... */
if (data.nesting->taglen + data.nesting->start < data.nesting->taglen ||
data.nesting->taglen + data.nesting->start < data.nesting->start) {
DEBUG(2,("check_spnego_blob_complete: integer wrap "
"data.nesting->taglen = %u, "
"data.nesting->start = %u\n",
(unsigned int)data.nesting->taglen,
(unsigned int)data.nesting->start ));
asn1_free(&data);
return NT_STATUS_INVALID_PARAMETER;
}
/* Total length of the needed asn1 is the tag length
* plus the current offset. */
needed_len = data.nesting->taglen + data.nesting->start;
asn1_free(&data);
DEBUG(10,("check_spnego_blob_complete: needed_len = %u, "
"pblob->length = %u\n",
(unsigned int)needed_len,
(unsigned int)pblob->length ));
if (needed_len <= pblob->length) {
/* Nothing to do - blob is complete. */
return NT_STATUS_OK;
}
/* Refuse the blob if it's bigger than 64k. */
if (needed_len > 65536) {
DEBUG(2,("check_spnego_blob_complete: needed_len too large (%u)\n",
(unsigned int)needed_len ));
return NT_STATUS_INVALID_PARAMETER;
}
/* We must store this blob until complete. */
pad = SMB_MALLOC(sizeof(struct pending_auth_data));
if (!pad) {
return NT_STATUS_NO_MEMORY;
}
pad->needed_len = needed_len - pblob->length;
pad->partial_data = data_blob(pblob->data, pblob->length);
if (pad->partial_data.data == NULL) {
SAFE_FREE(pad);
return NT_STATUS_NO_MEMORY;
}
pad->smbpid = smbpid;
pad->vuid = vuid;
DLIST_ADD(pd_list, pad);
return NT_STATUS_MORE_PROCESSING_REQUIRED;
}
