/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
/* p11-rpc-message.c - our marshalled PKCS#11 protocol.

   Copyright (C) 2008, Stef Walter

   The Mate Keyring Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The Mate Keyring Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the Mate Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
   Boston, MA 02110-1301, USA.

   Author: Stef Walter <stef@memberwebs.com>
*/

#include "config.h"

#include "gkm-rpc-layer.h"
#include "gkm-rpc-private.h"

#include <string.h>

#ifdef G_DISABLE_ASSERT
#define assert(x)
#else
#include <assert.h>
#endif

GkmRpcMessage*
gkm_rpc_message_new (EggBufferAllocator allocator)
{
	GkmRpcMessage *msg;

	assert (allocator);

	msg = (GkmRpcMessage*) (allocator)(NULL, sizeof (GkmRpcMessage));
	if (!msg)
		return NULL;
	memset (msg, 0, sizeof (*msg));

	if (!egg_buffer_init_full (&msg->buffer, 64, allocator)) {
		(allocator) (msg, 0); /* Frees allocation */
		return NULL;
	}

	gkm_rpc_message_reset (msg);

	return msg;
}

void
gkm_rpc_message_free (GkmRpcMessage *msg)
{
	EggBufferAllocator allocator;

	if (msg) {
		assert (msg->buffer.allocator);
		allocator = msg->buffer.allocator;
		egg_buffer_uninit (&msg->buffer);

		/* frees data buffer */
		(allocator) (msg, 0);
	}
}

void
gkm_rpc_message_reset (GkmRpcMessage *msg)
{
	assert (msg);

	msg->call_id = 0;
	msg->call_type = 0;
	msg->signature = NULL;
	msg->sigverify = NULL;
	msg->parsed = 0;

	egg_buffer_reset (&msg->buffer);
}

int
gkm_rpc_message_prep (GkmRpcMessage *msg, int call_id, GkmRpcMessageType type)
{
	int len;

	assert (type);
	assert (call_id >= GKM_RPC_CALL_ERROR);
	assert (call_id < GKM_RPC_CALL_MAX);

	gkm_rpc_message_reset (msg);

	if (call_id != GKM_RPC_CALL_ERROR) {

		/* The call id and signature */
		if (type == GKM_RPC_REQUEST)
			msg->signature = gkm_rpc_calls[call_id].request;
		else if (type == GKM_RPC_RESPONSE)
			msg->signature = gkm_rpc_calls[call_id].response;
		else
			assert (0 && "invalid message type");
		assert (msg->signature);
		msg->sigverify = msg->signature;
	}

	msg->call_id = call_id;
	msg->call_type = type;

	/* Encode the two of them */
	egg_buffer_add_uint32 (&msg->buffer, call_id);
	if (msg->signature) {
		len = strlen (msg->signature);
		egg_buffer_add_byte_array (&msg->buffer, (unsigned char*)msg->signature, len);
	}

	msg->parsed = 0;
	return !egg_buffer_has_error (&msg->buffer);
}

int
gkm_rpc_message_parse (GkmRpcMessage *msg, GkmRpcMessageType type)
{
	const unsigned char *val;
	size_t len;
	uint32_t call_id;

	msg->parsed = 0;

	/* Pull out the call identifier */
	if (!egg_buffer_get_uint32 (&msg->buffer, msg->parsed, &(msg->parsed), &call_id)) {
		gkm_rpc_warn ("invalid message: couldn't read call identifier");
		return 0;
	}

	msg->signature = msg->sigverify = NULL;

	/* If it's an error code then no more processing */
	if (call_id == GKM_RPC_CALL_ERROR) {
		if (type == GKM_RPC_REQUEST) {
			gkm_rpc_warn ("invalid message: error code in request");
			return 0;
		}

		return 1;
	}

	/* The call id and signature */
	if (call_id <= 0 || call_id >= GKM_RPC_CALL_MAX) {
		gkm_rpc_warn ("invalid message: bad call id: %d", call_id);
		return 0;
	}
	if (type == GKM_RPC_REQUEST)
		msg->signature = gkm_rpc_calls[call_id].request;
	else if (type == GKM_RPC_RESPONSE)
		msg->signature = gkm_rpc_calls[call_id].response;
	else
		assert (0 && "invalid message type");
	msg->call_id = call_id;
	msg->call_type = type;
	msg->sigverify = msg->signature;

	/* Verify the incoming signature */
	if (!egg_buffer_get_byte_array (&msg->buffer, msg->parsed, &(msg->parsed), &val, &len)) {
		gkm_rpc_warn ("invalid message: couldn't read signature");
		return 0;
	}

	if ((strlen (msg->signature) != len) || (memcmp (val, msg->signature, len) != 0)) {
		gkm_rpc_warn ("invalid message: signature doesn't match");
		return 0;
	}

	return 1;
}

int
gkm_rpc_message_equals (GkmRpcMessage *m1, GkmRpcMessage *m2)
{
	assert (m1 && m2);

	/* Any errors and messages are never equal */
	if (egg_buffer_has_error (&m1->buffer) ||
	    egg_buffer_has_error (&m2->buffer))
		return 0;

	/* Calls and signatures must be identical */
	if (m1->call_id != m2->call_id)
		return 0;
	if (m1->call_type != m2->call_type)
		return 0;
	if (m1->signature && m2->signature) {
		if (strcmp (m1->signature, m2->signature) != 0)
			return 0;
	} else if (m1->signature != m2->signature) {
		return 0;
	}

	/* Data in buffer must be identical */
	return egg_buffer_equal (&m1->buffer, &m2->buffer);
}

int
gkm_rpc_message_verify_part (GkmRpcMessage *msg, const char* part)
{
	int len, ok;

	if (!msg->sigverify)
		return 1;

	len = strlen (part);
	ok = (strncmp (msg->sigverify, part, len) == 0);
	if (ok)
		msg->sigverify += len;
	return ok;
}

int
gkm_rpc_message_write_attribute_buffer (GkmRpcMessage *msg, CK_ATTRIBUTE_PTR arr,
                                        CK_ULONG num)
{
	CK_ATTRIBUTE_PTR attr;
	CK_ULONG i;

	assert (!num || arr);
	assert (msg);

	/* Make sure this is in the rigth order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "fA"));

	/* Write the number of items */
	egg_buffer_add_uint32 (&msg->buffer, num);

	for (i = 0; i < num; ++i) {
		attr = &(arr[i]);

		/* The attribute type */
		egg_buffer_add_uint32 (&msg->buffer, attr->type);

		/* And the attribute buffer length */
		egg_buffer_add_uint32 (&msg->buffer, attr->pValue ? attr->ulValueLen : 0);
	}

	return !egg_buffer_has_error (&msg->buffer);
}

int
gkm_rpc_message_write_attribute_array (GkmRpcMessage *msg,
                                       CK_ATTRIBUTE_PTR arr, CK_ULONG num)
{
	CK_ULONG i;
	CK_ATTRIBUTE_PTR attr;
	unsigned char validity;

	assert (!num || arr);
	assert (msg);

	/* Make sure this is in the rigth order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "aA"));

	/* Write the number of items */
	egg_buffer_add_uint32 (&msg->buffer, num);

	for (i = 0; i < num; ++i) {
		attr = &(arr[i]);

		/* The attribute type */
		egg_buffer_add_uint32 (&msg->buffer, attr->type);

		/* Write out the attribute validity */
		validity = (((CK_LONG)attr->ulValueLen) == -1) ? 0 : 1;
		egg_buffer_add_byte (&msg->buffer, validity);

		/* The attribute length and value */
		if (validity) {
			egg_buffer_add_uint32 (&msg->buffer, attr->ulValueLen);
			egg_buffer_add_byte_array (&msg->buffer, attr->pValue, attr->ulValueLen);
		}
	}

	return !egg_buffer_has_error (&msg->buffer);
}

int
gkm_rpc_message_read_byte (GkmRpcMessage *msg, CK_BYTE *val)
{
	assert (msg);

	/* Make sure this is in the right order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "y"));
	return egg_buffer_get_byte (&msg->buffer, msg->parsed, &msg->parsed, val);
}

int
gkm_rpc_message_write_byte (GkmRpcMessage *msg, CK_BYTE val)
{
	assert (msg);

	/* Make sure this is in the right order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "y"));
	return egg_buffer_add_byte (&msg->buffer, val);
}

int
gkm_rpc_message_read_ulong (GkmRpcMessage *msg, CK_ULONG *val)
{
	uint64_t v;
	assert (msg);

	/* Make sure this is in the right order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "u"));

	if (!egg_buffer_get_uint64 (&msg->buffer, msg->parsed, &msg->parsed, &v))
		return 0;
	if (val)
		*val = (CK_ULONG)v;
	return 1;
}

int
gkm_rpc_message_write_ulong (GkmRpcMessage *msg, CK_ULONG val)
{
	assert (msg);

	/* Make sure this is in the rigth order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "u"));
	return egg_buffer_add_uint64 (&msg->buffer, val);
}

int
gkm_rpc_message_write_byte_buffer (GkmRpcMessage *msg, CK_ULONG count)
{
	assert (msg);

	/* Make sure this is in the right order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "fy"));
	return egg_buffer_add_uint32 (&msg->buffer, count);
}

int
gkm_rpc_message_write_byte_array (GkmRpcMessage *msg, CK_BYTE_PTR arr, CK_ULONG num)
{
	assert (msg);

	/* Make sure this is in the right order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "ay"));

	/* No array, no data, just length */
	if (!arr) {
		egg_buffer_add_byte (&msg->buffer, 0);
		egg_buffer_add_uint32 (&msg->buffer, num);
	} else {
		egg_buffer_add_byte (&msg->buffer, 1);
		egg_buffer_add_byte_array (&msg->buffer, arr, num);
	}

	return !egg_buffer_has_error (&msg->buffer);
}

int
gkm_rpc_message_write_ulong_buffer (GkmRpcMessage *msg, CK_ULONG count)
{
	assert (msg);

	/* Make sure this is in the right order */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "fu"));
	return egg_buffer_add_uint32 (&msg->buffer, count);
}

int
gkm_rpc_message_write_ulong_array (GkmRpcMessage *msg, CK_ULONG_PTR array, CK_ULONG n_array)
{
	CK_ULONG i;

	assert (msg);

	/* Check that we're supposed to have this at this point */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "au"));

	/* We send a byte which determines whether there's actual data present or not */
	egg_buffer_add_byte (&msg->buffer, array ? 1 : 0);
	egg_buffer_add_uint32 (&msg->buffer, n_array);

	/* Now send the data if valid */
	if (array) {
		for (i = 0; i < n_array; ++i)
			egg_buffer_add_uint64 (&msg->buffer, array[i]);
	}

	return !egg_buffer_has_error (&msg->buffer);
}

int
gkm_rpc_message_read_version (GkmRpcMessage *msg, CK_VERSION* version)
{
	assert (msg);
	assert (version);

	/* Check that we're supposed to have this at this point */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "v"));

	return egg_buffer_get_byte (&msg->buffer, msg->parsed, &msg->parsed, &version->major) &&
	       egg_buffer_get_byte (&msg->buffer, msg->parsed, &msg->parsed, &version->minor);
}

int
gkm_rpc_message_write_version (GkmRpcMessage *msg, CK_VERSION* version)
{
	assert (msg);
	assert (version);

	/* Check that we're supposed to have this at this point */
	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "v"));

	egg_buffer_add_byte (&msg->buffer, version->major);
	egg_buffer_add_byte (&msg->buffer, version->minor);

	return !egg_buffer_has_error (&msg->buffer);
}

int
gkm_rpc_message_read_space_string (GkmRpcMessage *msg, CK_UTF8CHAR* buffer, CK_ULONG length)
{
	const unsigned char *data;
	size_t n_data;

	assert (msg);
	assert (buffer);
	assert (length);

	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "s"));

	if (!egg_buffer_get_byte_array (&msg->buffer, msg->parsed, &msg->parsed, &data, &n_data))
		return 0;

	if (n_data != length) {
		gkm_rpc_warn ("invalid length space padded string received: %d != %d", length, n_data);
		return 0;
	}

	memcpy (buffer, data, length);
	return 1;
}

int
gkm_rpc_message_write_space_string (GkmRpcMessage *msg, CK_UTF8CHAR* buffer, CK_ULONG length)
{
	assert (msg);
	assert (buffer);
	assert (length);

	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "s"));

	return egg_buffer_add_byte_array (&msg->buffer, buffer, length);
}

int
gkm_rpc_message_write_zero_string (GkmRpcMessage *msg, CK_UTF8CHAR* string)
{
	assert (msg);
	assert (string);

	assert (!msg->signature || gkm_rpc_message_verify_part (msg, "z"));

	return egg_buffer_add_string (&msg->buffer, (const char*)string);
}
