/*
parse a spnego NTLMSSP challenge packet giving two security blobs
*/
bool spnego_parse_challenge(TALLOC_CTX *ctx, const DATA_BLOB blob,
DATA_BLOB *chal1, DATA_BLOB *chal2)
{
bool ret = false;
ASN1_DATA *data;
ZERO_STRUCTP(chal1);
ZERO_STRUCTP(chal2);
data = asn1_init(talloc_tos());
if (data == NULL) {
return false;
}
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,1)) goto err;
if (!asn1_end_tag(data)) goto err;
if (!asn1_start_tag(data,ASN1_CONTEXT(1))) goto err;
if (!asn1_check_OID(data, OID_NTLMSSP)) goto err;
if (!asn1_end_tag(data)) goto err;
if (!asn1_start_tag(data,ASN1_CONTEXT(2))) goto err;
if (!asn1_read_OctetString(data, ctx, chal1)) goto err;
if (!asn1_end_tag(data)) goto err;
/* the second challenge is optional (XP doesn't send it) */
if (asn1_tag_remaining(data)) {
if (!asn1_start_tag(data,ASN1_CONTEXT(3))) goto err;
if (!asn1_read_OctetString(data, ctx, chal2)) goto err;
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)) {
data_blob_free(chal1);
data_blob_free(chal2);
}
asn1_free(data);
return ret;
}
/*
parse a SPNEGO NTLMSSP auth packet. This contains the encrypted passwords
*/
BOOL spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
DATA_BLOB *auth)
{
ASN1_DATA data;
uint8 negResult;
if (NT_STATUS_IS_OK(nt_status)) {
negResult = SPNEGO_NEG_RESULT_ACCEPT;
} else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
negResult = SPNEGO_NEG_RESULT_INCOMPLETE;
} else {
negResult = SPNEGO_NEG_RESULT_REJECT;
}
asn1_load(&data, blob);
asn1_start_tag(&data, ASN1_CONTEXT(1));
asn1_start_tag(&data, ASN1_SEQUENCE(0));
asn1_start_tag(&data, ASN1_CONTEXT(0));
asn1_check_enumerated(&data, negResult);
asn1_end_tag(&data);
if (negResult == SPNEGO_NEG_RESULT_INCOMPLETE) {
asn1_start_tag(&data,ASN1_CONTEXT(1));
asn1_check_OID(&data, OID_NTLMSSP);
asn1_end_tag(&data);
asn1_start_tag(&data,ASN1_CONTEXT(2));
asn1_read_OctetString(&data, auth);
asn1_end_tag(&data);
}
asn1_end_tag(&data);
asn1_end_tag(&data);
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 True;
}
/*
parse a spnego NTLMSSP challenge packet giving two security blobs
*/
BOOL spnego_parse_challenge(const DATA_BLOB blob,
DATA_BLOB *chal1, DATA_BLOB *chal2)
{
BOOL ret;
ASN1_DATA data;
ZERO_STRUCTP(chal1);
ZERO_STRUCTP(chal2);
asn1_load(&data, blob);
asn1_start_tag(&data,ASN1_CONTEXT(1));
asn1_start_tag(&data,ASN1_SEQUENCE(0));
asn1_start_tag(&data,ASN1_CONTEXT(0));
asn1_check_enumerated(&data,1);
asn1_end_tag(&data);
asn1_start_tag(&data,ASN1_CONTEXT(1));
asn1_check_OID(&data, OID_NTLMSSP);
asn1_end_tag(&data);
asn1_start_tag(&data,ASN1_CONTEXT(2));
asn1_read_OctetString(&data, chal1);
asn1_end_tag(&data);
/* the second challenge is optional (XP doesn't send it) */
if (asn1_tag_remaining(&data)) {
asn1_start_tag(&data,ASN1_CONTEXT(3));
asn1_read_OctetString(&data, chal2);
asn1_end_tag(&data);
}
asn1_end_tag(&data);
asn1_end_tag(&data);
ret = !data.has_error;
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;
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;
}
asn1_load(data, blob);
asn1_start_tag(data, ASN1_CONTEXT(1));
asn1_start_tag(data, ASN1_SEQUENCE(0));
asn1_start_tag(data, ASN1_CONTEXT(0));
asn1_check_enumerated(data, negResult);
asn1_end_tag(data);
*auth = data_blob_null;
if (asn1_tag_remaining(data)) {
asn1_start_tag(data,ASN1_CONTEXT(1));
asn1_check_OID(data, mechOID);
asn1_end_tag(data);
if (asn1_tag_remaining(data)) {
asn1_start_tag(data,ASN1_CONTEXT(2));
asn1_read_OctetString(data, ctx, auth);
asn1_end_tag(data);
}
} else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
data->has_error = 1;
}
/* 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;
asn1_start_tag(data, ASN1_CONTEXT(3));
asn1_read_OctetString(data, ctx, &mechList);
asn1_end_tag(data);
data_blob_free(&mechList);
DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
"ignoring.\n"));
}
asn1_end_tag(data);
asn1_end_tag(data);
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 True;
}
