encrypt.c

inetutils的源代码

		if (encrypt_debug_mode)
			printf(">>>%s: He is supporting %s (%d)\r\n",
				Name,
				ENCTYPE_NAME(type), type);
		if ((type < ENCTYPE_CNT) &&
		    (I_SUPPORT_ENCRYPT & typemask(type))) {
			remote_supports_decrypt |= typemask(type);
			if (use_type == 0)
				use_type = type;
		}
	}
	if (use_type) {
		ep = findencryption(use_type);
		if (!ep)
			return;
		type = ep->start ? (*ep->start)(DIR_ENCRYPT, Server) : 0;
		if (encrypt_debug_mode)
			printf(">>>%s: (*ep->start)() returned %d\r\n",
					Name, type);
		if (type < 0)
			return;
		encrypt_mode = use_type;
		if (type == 0)
			encrypt_start_output(use_type);
	}
}

	void
encrypt_is(data, cnt)
	unsigned char *data;
	int cnt;
{
	Encryptions *ep;
	register int type, ret;

	if (--cnt < 0)
		return;
	type = *data++;
	if (type < ENCTYPE_CNT)
		remote_supports_encrypt |= typemask(type);
	if (!(ep = finddecryption(type))) {
		if (encrypt_debug_mode)
			printf(">>>%s: Can't find type %s (%d) for initial negotiation\r\n",
				Name,
				ENCTYPE_NAME_OK(type)
					? ENCTYPE_NAME(type) : "(unknown)",
				type);
		return;
	}
	if (!ep->is) {
		if (encrypt_debug_mode)
			printf(">>>%s: No initial negotiation needed for type %s (%d)\r\n",
				Name,
				ENCTYPE_NAME_OK(type)
					? ENCTYPE_NAME(type) : "(unknown)",
				type);
		ret = 0;
	} else {
		ret = (*ep->is)(data, cnt);
		if (encrypt_debug_mode)
			printf("(*ep->is)(%x, %d) returned %s(%d)\n", data, cnt,
				(ret < 0) ? "FAIL " :
				(ret == 0) ? "SUCCESS " : "MORE_TO_DO ", ret);
	}
	if (ret < 0) {
		autodecrypt = 0;
	} else {
		decrypt_mode = type;
		if (ret == 0 && autodecrypt)
			encrypt_send_request_start();
	}
}

	void
encrypt_reply(data, cnt)
	unsigned char *data;
	int cnt;
{
	Encryptions *ep;
	register int ret, type;

	if (--cnt < 0)
		return;
	type = *data++;
	if (!(ep = findencryption(type))) {
		if (encrypt_debug_mode)
			printf(">>>%s: Can't find type %s (%d) for initial negotiation\r\n",
				Name,
				ENCTYPE_NAME_OK(type)
					? ENCTYPE_NAME(type) : "(unknown)",
				type);
		return;
	}
	if (!ep->reply) {
		if (encrypt_debug_mode)
			printf(">>>%s: No initial negotiation needed for type %s (%d)\r\n",
				Name,
				ENCTYPE_NAME_OK(type)
					? ENCTYPE_NAME(type) : "(unknown)",
				type);
		ret = 0;
	} else {
		ret = (*ep->reply)(data, cnt);
		if (encrypt_debug_mode)
			printf("(*ep->reply)(%x, %d) returned %s(%d)\n",
				data, cnt,
				(ret < 0) ? "FAIL " :
				(ret == 0) ? "SUCCESS " : "MORE_TO_DO ", ret);
	}
	if (encrypt_debug_mode)
		printf(">>>%s: encrypt_reply returned %d\n", Name, ret);
	if (ret < 0) {
		autoencrypt = 0;
	} else {
		encrypt_mode = type;
		if (ret == 0 && autoencrypt)
			encrypt_start_output(type);
	}
}

/*
 * Called when a ENCRYPT START command is received.
 */
	void
encrypt_start(data, cnt)
	unsigned char *data;
	int cnt;
{
	Encryptions *ep;

	if (!decrypt_mode) {
		/*
		 * Something is wrong.  We should not get a START
		 * command without having already picked our
		 * decryption scheme.  Send a REQUEST-END to
		 * attempt to clear the channel...
		 */
		printf("%s: Warning, Cannot decrypt input stream!!!\r\n", Name);
		encrypt_send_request_end();
		return;
	}

	if (ep = finddecryption(decrypt_mode)) {
		decrypt_input = ep->input;
		if (encrypt_verbose)
			printf("[ Input is now decrypted with type %s ]\r\n",
				ENCTYPE_NAME(decrypt_mode));
		if (encrypt_debug_mode)
			printf(">>>%s: Start to decrypt input with type %s\r\n",
				Name, ENCTYPE_NAME(decrypt_mode));
	} else {
		printf("%s: Warning, Cannot decrypt type %s (%d)!!!\r\n",
				Name,
				ENCTYPE_NAME_OK(decrypt_mode)
					? ENCTYPE_NAME(decrypt_mode)
					: "(unknown)",
				decrypt_mode);
		encrypt_send_request_end();
	}
}

	void
encrypt_session_key(key, server)
	Session_Key *key;
	int server;
{
	Encryptions *ep = encryptions;

	havesessionkey = 1;

	while (ep->type) {
		if (ep->session)
			(*ep->session)(key, server);
#ifdef notdef
		if (!encrypt_output && autoencrypt && !server)
			encrypt_start_output(ep->type);
		if (!decrypt_input && autodecrypt && !server)
			encrypt_send_request_start();
#endif
		++ep;
	}
}

/*
 * Called when ENCRYPT END is received.
 */
	void
encrypt_end()
{
	decrypt_input = 0;
	if (encrypt_debug_mode)
		printf(">>>%s: Input is back to clear text\r\n", Name);
	if (encrypt_verbose)
		printf("[ Input is now clear text ]\r\n");
}

/*
 * Called when ENCRYPT REQUEST-END is received.
 */
	void
encrypt_request_end()
{
	encrypt_send_end();
}

/*
 * Called when ENCRYPT REQUEST-START is received.  If we receive
 * this before a type is picked, then that indicates that the
 * other side wants us to start encrypting data as soon as we
 * can.
 */
	void
encrypt_request_start(data, cnt)
	unsigned char *data;
	int cnt;
{
	if (encrypt_mode == 0)  {
		if (Server)
			autoencrypt = 1;
		return;
	}
	encrypt_start_output(encrypt_mode);
}

static unsigned char str_keyid[(MAXKEYLEN*2)+5] = { IAC, SB, TELOPT_ENCRYPT };

encrypt_enc_keyid(keyid, len)
	unsigned char *keyid;
	int len;
{
	encrypt_keyid(&ki[1], keyid, len);
}

encrypt_dec_keyid(keyid, len)
	unsigned char *keyid;
	int len;
{
	encrypt_keyid(&ki[0], keyid, len);
}

encrypt_keyid(kp, keyid, len)
	struct key_info *kp;
	unsigned char *keyid;
	int len;
{
	Encryptions *ep;
	unsigned char *strp, *cp;
	int dir = kp->dir;
	register int ret = 0;

	if (!(ep = (*kp->getcrypt)(*kp->modep))) {
		if (len == 0)
			return;
		kp->keylen = 0;
	} else if (len == 0) {
		/*
		 * Empty option, indicates a failure.
		 */
		if (kp->keylen == 0)
			return;
		kp->keylen = 0;
		if (ep->keyid)
			(void)(*ep->keyid)(dir, kp->keyid, &kp->keylen);

	} else if ((len != kp->keylen) ||
		   (memcmp(keyid, kp->keyid, len) != 0)) {
		/*
		 * Length or contents are different
		 */
		kp->keylen = len;
		memmove(kp->keyid, keyid, len);
		if (ep->keyid)
			(void)(*ep->keyid)(dir, kp->keyid, &kp->keylen);
	} else {
		if (ep->keyid)
			ret = (*ep->keyid)(dir, kp->keyid, &kp->keylen);
		if ((ret == 0) && (dir == DIR_ENCRYPT) && autoencrypt)
			encrypt_start_output(*kp->modep);
		return;
	}

	encrypt_send_keyid(dir, kp->keyid, kp->keylen, 0);
}

	void
encrypt_send_keyid(dir, keyid, keylen, saveit)
	int dir;
	unsigned char *keyid;
	int keylen;
	int saveit;
{
	unsigned char *strp;

	str_keyid[3] = (dir == DIR_ENCRYPT)
			? ENCRYPT_ENC_KEYID : ENCRYPT_DEC_KEYID;
	if (saveit) {
		struct key_info *kp = &ki[(dir == DIR_ENCRYPT) ? 0 : 1];
		memmove(kp->keyid, keyid, keylen);
		kp->keylen = keylen;
	}

	for (strp = &str_keyid[4]; keylen > 0; --keylen) {
		if ((*strp++ = *keyid++) == IAC)
			*strp++ = IAC;
	}
	*strp++ = IAC;
	*strp++ = SE;
	net_write(str_keyid, strp - str_keyid);
	printsub('>', &str_keyid[2], strp - str_keyid - 2);
}

	void
encrypt_auto(on)
	int on;
{
	if (on < 0)
		autoencrypt ^= 1;
	else
		autoencrypt = on ? 1 : 0;
}

	void
decrypt_auto(on)
	int on;
{
	if (on < 0)
		autodecrypt ^= 1;
	else
		autodecrypt = on ? 1 : 0;
}

	void
encrypt_start_output(type)
	int type;
{
	Encryptions *ep;
	register unsigned char *p;
	register int i;

	if (!(ep = findencryption(type))) {
		if (encrypt_debug_mode) {
			printf(">>>%s: Can't encrypt with type %s (%d)\r\n",
				Name,
				ENCTYPE_NAME_OK(type)
					? ENCTYPE_NAME(type) : "(unknown)",
				type);
		}
		return;
	}
	if (ep->start) {
		i = (*ep->start)(DIR_ENCRYPT, Server);
		if (encrypt_debug_mode) {
			printf(">>>%s: Encrypt start: %s (%d) %s\r\n",
				Name,
				(i < 0) ? "failed" :
					"initial negotiation in progress",
				i, ENCTYPE_NAME(type));
		}
		if (i)
			return;
	}
	p = str_start + 3;
	*p++ = ENCRYPT_START;
	for (i = 0; i < ki[0].keylen; ++i) {
		if ((*p++ = ki[0].keyid[i]) == IAC)
			*p++ = IAC;
	}
	*p++ = IAC;
	*p++ = SE;
	net_write(str_start, p - str_start);
	net_encrypt();
	printsub('>', &str_start[2], p - &str_start[2]);
	/*
	 * If we are already encrypting in some mode, then
	 * encrypt the ring (which includes our request) in
	 * the old mode, mark it all as "clear text" and then
	 * switch to the new mode.
	 */
	encrypt_output = ep->output;
	encrypt_mode = type;
	if (encrypt_debug_mode)
		printf(">>>%s: Started to encrypt output with type %s\r\n",
			Name, ENCTYPE_NAME(type));
	if (encrypt_verbose)
		printf("[ Output is now encrypted with type %s ]\r\n",
			ENCTYPE_NAME(type));
}

	void
encrypt_send_end()
{
	if (!encrypt_output)
		return;

	str_end[3] = ENCRYPT_END;
	net_write(str_end, sizeof(str_end));
	net_encrypt();
	printsub('>', &str_end[2], sizeof(str_end) - 2);
	/*
	 * Encrypt the output buffer now because it will not be done by
	 * netflush...
	 */
	encrypt_output = 0;
	if (encrypt_debug_mode)
		printf(">>>%s: Output is back to clear text\r\n", Name);
	if (encrypt_verbose)
		printf("[ Output is now clear text ]\r\n");
}

	void
encrypt_send_request_start()
{
	register unsigned char *p;
	register int i;

	p = &str_start[3];
	*p++ = ENCRYPT_REQSTART;
	for (i = 0; i < ki[1].keylen; ++i) {
		if ((*p++ = ki[1].keyid[i]) == IAC)
			*p++ = IAC;
	}
	*p++ = IAC;
	*p++ = SE;
	net_write(str_start, p - str_start);
	printsub('>', &str_start[2], p - &str_start[2]);
	if (encrypt_debug_mode)
		printf(">>>%s: Request input to be encrypted\r\n", Name);
}

	void
encrypt_send_request_end()
{
	str_end[3] = ENCRYPT_REQEND;
	net_write(str_end, sizeof(str_end));
	printsub('>', &str_end[2], sizeof(str_end) - 2);

	if (encrypt_debug_mode)
		printf(">>>%s: Request input to be clear text\r\n", Name);
}

	void
encrypt_wait()
{
	register int encrypt, decrypt;
	if (encrypt_debug_mode)
		printf(">>>%s: in encrypt_wait\r\n", Name);
	if (!havesessionkey || !(I_SUPPORT_ENCRYPT & remote_supports_decrypt))
		return;
	while (autoencrypt && !encrypt_output)
		if (telnet_spin())
			return;
}

	void
encrypt_debug(mode)
	int mode;
{
	encrypt_debug_mode = mode;
}

	void
encrypt_gen_printsub(data, cnt, buf, buflen)
	unsigned char *data, *buf;
	int cnt, buflen;
{
	char tbuf[16], *cp;

	cnt -= 2;
	data += 2;
	buf[buflen-1] = '\0';
	buf[buflen-2] = '*';
	buflen -= 2;;
	for (; cnt > 0; cnt--, data++) {
		sprintf(tbuf, " %d", *data);
		for (cp = tbuf; *cp && buflen > 0; --buflen)
			*buf++ = *cp++;
		if (buflen <= 0)
			return;
	}
	*buf = '\0';
}

	void
encrypt_printsub(data, cnt, buf, buflen)
	unsigned char *data, *buf;
	int cnt, buflen;
{
	Encryptions *ep;
	register int type = data[1];

	for (ep = encryptions; ep->type && ep->type != type; ep++)
		;

	if (ep->printsub)
		(*ep->printsub)(data, cnt, buf, buflen);
	else
		encrypt_gen_printsub(data, cnt, buf, buflen);
}
#endif	/* ENCRYPTION */