// -*- mode: c; tab-width: 8; indent-tabs-mode: 1; st-rulers: [70] -*-
// vim: ts=8 sw=8 ft=c noet

#include "libsodium_api_crypto_stream.h"

static void	LS_API_EXEC(crypto_stream, keybytes);
static void	LS_API_EXEC(crypto_stream, noncebytes);
static void	LS_API_EXEC(crypto_stream, primitive);
static int	LS_API_INIT(crypto_stream, crypto_stream);
static void	LS_API_EXEC(crypto_stream, crypto_stream);
static int	LS_API_INIT(crypto_stream, xor);
static void	LS_API_EXEC(crypto_stream, xor);

libsodium_function_t	libsodium_functions_crypto_stream[] = {
	LS_API_R_ARG0(crypto_stream, keybytes),
	LS_API_R_ARG0(crypto_stream, noncebytes),
	LS_API_R_ARG0(crypto_stream, primitive),
	LS_API_R_ARGV(crypto_stream, crypto_stream, 3),
	LS_API_R_ARGV(crypto_stream, xor, 3),
	{NULL}
};

/* crypto_stream_keybytes/0 */

static void
LS_API_EXEC(crypto_stream, keybytes)
{
	size_t keybytes;

	keybytes = crypto_stream_keybytes();

	ErlDrvTermData spec[] = {
		LS_RES_TAG(request),
		ERL_DRV_UINT, (ErlDrvUInt)(keybytes),
		ERL_DRV_TUPLE, 2
	};

	LS_RESPOND(request, spec, __FILE__, __LINE__);
}

/* crypto_stream_noncebytes/0 */

static void
LS_API_EXEC(crypto_stream, noncebytes)
{
	size_t noncebytes;

	noncebytes = crypto_stream_noncebytes();

	ErlDrvTermData spec[] = {
		LS_RES_TAG(request),
		ERL_DRV_UINT, (ErlDrvUInt)(noncebytes),
		ERL_DRV_TUPLE, 2
	};

	LS_RESPOND(request, spec, __FILE__, __LINE__);
}

/* crypto_stream_primitive/0 */

static void
LS_API_EXEC(crypto_stream, primitive)
{
	const char *primitive;

	primitive = crypto_stream_primitive();

	ErlDrvTermData spec[] = {
		LS_RES_TAG(request),
		ERL_DRV_ATOM, driver_mk_atom((char *)(primitive)),
		ERL_DRV_TUPLE, 2
	};

	LS_RESPOND(request, spec, __FILE__, __LINE__);
}

/* crypto_stream_crypto_stream/3 */

typedef struct LS_API_F_ARGV(crypto_stream, crypto_stream) {
	unsigned long long	clen;
	const unsigned char	*n;
	const unsigned char	*k;
} LS_API_F_ARGV_T(crypto_stream, crypto_stream);

static int
LS_API_INIT(crypto_stream, crypto_stream)
{
	LS_API_F_ARGV_T(crypto_stream, crypto_stream) *argv;
	int skip;
	int type;
	int type_length;
	unsigned long long clen;
	size_t noncebytes;
	size_t keybytes;
	ErlDrvSizeT x;
	void *p;

	if (ei_decode_ulong(buffer, index, (unsigned long *)&(clen)) < 0) {
		return -1;
	}

	noncebytes = crypto_stream_noncebytes();

	if (ei_get_type(buffer, index, &type, &type_length) < 0
			|| type != ERL_BINARY_EXT
			|| type_length != noncebytes) {
		return -1;
	}

	skip = *index;

	if (ei_skip_term(buffer, &skip) < 0) {
		return -1;
	}

	keybytes = crypto_stream_keybytes();

	if (ei_get_type(buffer, &skip, &type, &type_length) < 0
			|| type != ERL_BINARY_EXT
			|| type_length != keybytes) {
		return -1;
	}

	x = (ErlDrvSizeT)(noncebytes + keybytes + (sizeof (LS_API_F_ARGV_T(crypto_stream, crypto_stream))));
	p = (void *)(driver_alloc(x));

	if (p == NULL) {
		return -1;
	}

	argv = (LS_API_F_ARGV_T(crypto_stream, crypto_stream) *)(p);
	p += (sizeof (LS_API_F_ARGV_T(crypto_stream, crypto_stream)));
	argv->clen = clen;
	argv->n = (const unsigned char *)(p);
	p += noncebytes;
	argv->k = (const unsigned char *)(p);

	if (ei_decode_binary(buffer, index, (void *)(argv->n), NULL) < 0) {
		(void) driver_free(argv);
		return -1;
	}

	if (ei_decode_binary(buffer, index, (void *)(argv->k), NULL) < 0) {
		(void) driver_free(argv);
		return -1;
	}

	request->argv = (void *)(argv);

	return 0;
}

static void
LS_API_EXEC(crypto_stream, crypto_stream)
{
	LS_API_F_ARGV_T(crypto_stream, crypto_stream) *argv;
	LS_API_READ_ARGV(crypto_stream, crypto_stream);
	unsigned char *c;

	c = (unsigned char *)(driver_alloc((ErlDrvSizeT)(argv->clen)));

	if (c == NULL) {
		LS_FAIL_OOM(request->port->drv_port);
		return;
	}

	(void) crypto_stream(c, argv->clen, argv->n, argv->k);

	ErlDrvTermData spec[] = {
		LS_RES_TAG(request),
		ERL_DRV_BUF2BINARY, (ErlDrvTermData)(c), argv->clen,
		ERL_DRV_TUPLE, 2
	};

	LS_RESPOND(request, spec, __FILE__, __LINE__);

	(void) driver_free(c);
}

/* crypto_stream_xor/3 */

typedef struct LS_API_F_ARGV(crypto_stream, xor) {
	const unsigned char	*m;
	unsigned long long	mlen;
	const unsigned char	*n;
	const unsigned char	*k;
} LS_API_F_ARGV_T(crypto_stream, xor);

static int
LS_API_INIT(crypto_stream, xor)
{
	LS_API_F_ARGV_T(crypto_stream, xor) *argv;
	int skip;
	int type;
	int type_length;
	unsigned long long mlen;
	size_t noncebytes;
	size_t keybytes;
	ErlDrvSizeT x;
	void *p;

	if (ei_get_type(buffer, index, &type, &type_length) < 0
			|| type != ERL_BINARY_EXT) {
		return -1;
	}

	mlen = (unsigned long long)(type_length);

	skip = *index;

	if (ei_skip_term(buffer, &skip) < 0) {
		return -1;
	}

	noncebytes = crypto_stream_noncebytes();

	if (ei_get_type(buffer, &skip, &type, &type_length) < 0
			|| type != ERL_BINARY_EXT
			|| type_length != noncebytes) {
		return -1;
	}

	if (ei_skip_term(buffer, &skip) < 0) {
		return -1;
	}

	keybytes = crypto_stream_keybytes();

	if (ei_get_type(buffer, &skip, &type, &type_length) < 0
			|| type != ERL_BINARY_EXT
			|| type_length != keybytes) {
		return -1;
	}

	x = (ErlDrvSizeT)(mlen + noncebytes + keybytes + (sizeof (LS_API_F_ARGV_T(crypto_stream, xor))));
	p = (void *)(driver_alloc(x));

	if (p == NULL) {
		return -1;
	}

	argv = (LS_API_F_ARGV_T(crypto_stream, xor) *)(p);
	p += (sizeof (LS_API_F_ARGV_T(crypto_stream, xor)));
	argv->m = (const unsigned char *)(p);
	p += mlen;
	argv->n = (const unsigned char *)(p);
	p += noncebytes;
	argv->k = (const unsigned char *)(p);

	if (ei_decode_binary(buffer, index, (void *)(argv->m), (long *)&(argv->mlen)) < 0) {
		(void) driver_free(argv);
		return -1;
	}

	if (ei_decode_binary(buffer, index, (void *)(argv->n), NULL) < 0) {
		(void) driver_free(argv);
		return -1;
	}

	if (ei_decode_binary(buffer, index, (void *)(argv->k), NULL) < 0) {
		(void) driver_free(argv);
		return -1;
	}

	request->argv = (void *)(argv);

	return 0;
}

static void
LS_API_EXEC(crypto_stream, xor)
{
	LS_API_F_ARGV_T(crypto_stream, xor) *argv;
	LS_API_READ_ARGV(crypto_stream, xor);
	unsigned char *c;

	c = (unsigned char *)(argv->m);

	(void) crypto_stream_xor(c, argv->m, argv->mlen, argv->n, argv->k);

	ErlDrvTermData spec[] = {
		LS_RES_TAG(request),
		ERL_DRV_BUF2BINARY, (ErlDrvTermData)(c), argv->mlen,
		ERL_DRV_TUPLE, 2
	};

	LS_RESPOND(request, spec, __FILE__, __LINE__);
}