/*
 * TEA Total Copyright (c) Alex Holden <alex@linuxhacker.org> 2000, 2001.
 *
 * This code is public domain; you can do whatever you want with it, though I
 * would prefer you to contribute any bug fixes back to me if possible.
 * This software comes with NO WARRANTY WHATSOEVER, not even the implied
 * warranties of merchantability and fitness for a particular purpose.
 *
 * tea-kgen.c: The tea-kgen applet.
 */

#include <unistd.h>

#include "teatotal.h"
#include "tea-kgen.h"

#ifdef BUILD_PPKEYS
#include "readkey.h"
#include "btea.h"
#endif

/*
 * Initialise the tea_kgen applet.
 */
void init_tea_kgen(teastate *state)
{
	/* Check for the help flag */
	if(getflag(state->ga, 'h', "help")) usage(state);

#ifdef BUILD_PPKEYS
	/* Get the input key password */
	state->inkeypass = getarg(state->ga, 'p', NULL);
	/* Get the output key password */
	state->outkeypass = getarg(state->ga, 'k', NULL);
	/* Check if we should password protect the generated key */
	state->protkey = getflag(state->ga, 'P', NULL);
	/* Check if we should convert the specified key file instead of
	 * generating a new one */
	state->convkey = getflag(state->ga, 'c', NULL);
#endif

	/* The first unused argument is the name of the key file */
	state->keyfile = getarg(state->ga, 0, NULL);

	/* Check if "-" (stdout) was specified */
	if(state->keyfile && (state->keyfile[0] == '-') && !state->keyfile[1])
		state->keyfile = NULL;
}

/*
 * The tea-kgen applet.
 */
void do_tea_kgen(teastate *state)
{
	u32 *l, k[4];
	u8 binkey[20];
	int i, fd;
	char buf[KEY_LENGTH + 2], *p;

	/* Write the headers */
	memcpy(buf, KEY_HEADER, (sizeof(KEY_HEADER) - 1));
	l = (u32 *)binkey;
	*l = KEY_MAGIC;

#ifdef BUILD_PPKEYS
	/* Read the specified input key, or generate a new one */
	if(state->convkey) read_key(state);
	else generate_key(state);
#else
	/* Generate a new key */
	generate_key(state);
#endif

	/* Load the key as big endian */
	l = (u32 *)&binkey[4];
	for(i = 0; i < 4; i++)
#if BYTE_ORDER == LITTLE_ENDIAN
		l[i] = swapu32(state->k[i]);
#else
		l[i] = state->k[i];
#endif

#ifdef BUILD_PPKEYS
	/* If asked to encrypt the key */
	if(state->protkey) {

		/* Read the password to encrypt the key with */
		read_pass(state, k, 0, 1);

		/* Encrypt the key */
#if BYTE_ORDER == LITTLE_ENDIAN
		btea((u32 *)binkey, k, (20 / 4), 0, 1);
#else
		btea((u32 *)binkey, k, (20 / 4), 0, 0);
#endif

		/* Set the key type to non encrypted */
		buf[sizeof(KEY_HEADER) - 1] = KEY_TEAENC;
	} else {
		/* Set the key type to non encrypted */
		buf[sizeof(KEY_HEADER) - 1] = KEY_NOENC;
	}
#else
	/* Set the key type to non encrypted */
	buf[sizeof(KEY_HEADER) - 1] = KEY_NOENC;
#endif

	/* Open the output key file */
	fd = openwrite(state->keyfile);

	/* Convert the binary key data to a hex ascii string */
	p = &buf[sizeof(KEY_HEADER)];
	for(i = 0; i < 20; i++) {
		inttohex(binkey[i], p);
		p+= 2;
	}
#ifdef DOS_LINE_ENDINGS
	*p++ = '\r';
#endif
	*p = '\n';

	/* Write the string out to the key file (or stdout) */
#ifdef DOS_LINE_ENDINGS
	if(safe_write(fd, buf, (KEY_LENGTH + 2)) != (KEY_LENGTH + 2))
#else
	if(safe_write(fd, buf, (KEY_LENGTH + 1)) != (KEY_LENGTH + 1))
#endif
		die("Key write failed");

	/* Close the key file, unless it is stdout */
	if(state->keyfile) close(fd);
}