Esempio n. 1
0
/*
  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;
}
Esempio n. 2
0
/*
  generate a krb5 GSS-API wrapper packet given a ticket
*/
DATA_BLOB spnego_gen_krb5_wrap(TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
{
	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_KERBEROS5)) goto err;

	if (!asn1_write(data, tok_id, 2)) goto err;
	if (!asn1_write(data, ticket.data, ticket.length)) goto err;
	if (!asn1_pop_tag(data)) goto err;

	if (!asn1_extract_blob(data, ctx, &ret)) {
		goto err;
	}

  err:

	if (asn1_has_error(data)) {
		DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
			  (int)asn1_current_ofs(data)));
	}

	asn1_free(data);

	return ret;
}
Esempio n. 3
0
/*
  magic check a GSS-API wrapper packet for an Kerberos OID
*/
static bool gensec_gssapi_check_oid(const DATA_BLOB *blob, const char *oid)
{
	bool ret = false;
	struct asn1_data *data = asn1_init(NULL);

	if (!data) 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)) goto err;

	ret = !asn1_has_error(data);

  err:

	asn1_free(data);
	return ret;
}
Esempio n. 4
0
/*
 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_t 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) {
		asn1_set_error(data);
		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 = !asn1_has_error(data);

  err:

	if (asn1_has_error(data)) {
		DEBUG(3, ("spnego_parse_auth_response failed at %d\n",
			  (int)asn1_current_ofs(data)));
		asn1_free(data);
		data_blob_free(auth);
		return false;
	}

	asn1_free(data);
	return ret;
}
Esempio n. 5
0
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;

	if (!asn1_extract_blob(data, ctx, &ret)) {
		goto err;
	}

  err:

	if (asn1_has_error(data)) {
		DEBUG(1, ("Failed to build negTokenInit at offset %d\n",
			  (int)asn1_current_ofs(data)));
	}

	asn1_free(data);

	return ret;
}
Esempio n. 6
0
/*
  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;
}