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version 6.9

/*************************************************************************
* (C) 2010 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
*  by Michael Pounov <misho@elwix.org>
*
* $Author: misho $
* $Id: crypt.c,v 1.10 2014/02/08 22:06:17 misho Exp $
*
**************************************************************************
The ELWIX and AITNET software is distributed under the following
terms:

All of the documentation and software included in the ELWIX and AITNET
Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>

Copyright 2004 - 2014
	by Michael Pounov <misho@elwix.org>.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by Michael Pounov <misho@elwix.org>
ELWIX - Embedded LightWeight unIX and its contributors.
4. Neither the name of AITNET nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
*/
#include "global.h"


/*
 * ioCipher() - Cipher wrapper for all supported crypto algorythms
 *
 * @pInput = input buffer
 * @inLen = input buffer len
 * @ppOutput = output allocated buffe, must be e_free after use
 * @Cipher = cipher engine, like EVP_bf_cbc() or etc...
 * @pKey = key
 * @pIV = IV, salt (8 bytes)
 * @nMode = Mode 0 - decrypting or 1 - encrypting
 * return: 0 not present data or error!; >0 number of processed and returned bytes into ppOutput
*/
int
ioCipher(u_char *pInput, int inLen, u_char **ppOutput, const EVP_CIPHER *Cipher, 
		u_char *pKey, u_char *pIV, int nMode)
{
	EVP_CIPHER_CTX ctx;
	int chunk, buflen, outlen = 0;
	u_char *pos, *buf = NULL;

	if (!pInput || !inLen || !ppOutput || nMode & 0xFFFFFFFE)
		return 0;
	buf = e_malloc(inLen + EVP_MAX_BLOCK_LENGTH);
	if (!buf) {
		LOGERR;
		goto end;
	} else
		memset(buf, 0, inLen + EVP_MAX_BLOCK_LENGTH);

	EVP_CIPHER_CTX_init(&ctx);
	EVP_CipherInit_ex(&ctx, Cipher, NULL, pKey, pIV, nMode);

	for (outlen = 0, buflen = -1, pos = pInput; inLen; outlen += buflen) {
		chunk = inLen > 7 ? 8 : inLen;

		if (!EVP_CipherUpdate(&ctx, buf + outlen, &buflen, pos, chunk)) {
			EVP_CIPHER_CTX_cleanup(&ctx);
			outlen = 0;
			e_free(buf);
			buf = NULL;
			goto end;
		} else {
			if (nMode && !buflen)
				break;

			pos += chunk;
			inLen -= chunk;
		}
	}
	if (!EVP_CipherFinal_ex(&ctx, buf + outlen, &buflen)) {
		outlen = 0;
		e_free(buf);
		buf = NULL;
	} else
		outlen += buflen;

	EVP_CIPHER_CTX_cleanup(&ctx);
end:
	*ppOutput = buf;
	return outlen;
}

/*
 * io_Blowfish() - Blowfish cipher algorythm, work with ASCII hex strings
 *
 * @pInput = input buffer
 * @inLen = input buffer len
 * @ppOutput = output allocated buffe, must be e_free after use
 * @pKey = key
 * @pIV = IV, salt (8 bytes)
 * @nMode = Mode 0 - decrypting or 1 - encrypting
 * return: 0 not present data or error!; >0 number of processed and returned bytes into ppOutput
*/
int
io_Blowfish(u_char *pInput, int inLen, u_char **ppOutput, u_char *pKey, u_char *pIV, int nMode)
{
	int len, ret;
	register int i;
	char bufCH[3], *str = NULL;
	u_char *buf = NULL;

	if (!pInput || !inLen || !ppOutput || nMode & 0xFFFFFFFE)
		return 0;

	if (nMode) {
		len = strlen((char*) pInput);
		str = e_strdup((char*) pInput);
	} else {
		len = strlen((char*) pInput) / 2;
		str = e_malloc(len + 1);
		if (!str) {
			LOGERR;
			return 0;
		} else
			memset(str, 0, len + 1);

		for (i = 0; i < len * 2; i += 2) {
			strlcpy(bufCH, (char*) &pInput[i], 3);
			str[i / 2] = (u_char) strtol(bufCH, NULL, 16);
		}
	}

	ret = len = ioCipher((u_char*) str, len, &buf, EVP_bf_cbc(), pKey, pIV, nMode);
	e_free(str);

	if (nMode) {
		ret *= 2;
		*ppOutput = e_malloc(ret + 1);
		if (!*ppOutput) {
			LOGERR;
			return 0;
		} else
			memset(*ppOutput, 0, ret + 1);

		for (i = 0; i < len; i++) {
			memset(bufCH, 0, 3);
			snprintf(bufCH, 3, "%02x", buf[i]);
			strlcat((char*) *ppOutput, bufCH, ret + 1);
		}
	} else
		if (ret && buf)
			*ppOutput = (u_char*) e_strdup((char*) buf);

	return ret;
}

/*
 * io_ctr_AES() - Encrypt/Decrypt stream cipher CTR_AES
 *
 * @pInput = Input buffer with ASCII
 * @inLen = Input buffer data length
 * @ppOutput = Output buffer with cipher data, must be e_free after use
 * @pKey = Key
 * @IV = IVector/Nonce/Counter, Warning: IV must be variable, because we write there!!!
 * return: -1 error or >-1 how many cipher blocks proceeded
 */
int
io_ctr_AES(u_char *pInput, int inLen, u_char **ppOutput, u_char *pKey, u_char IV[AES_BLOCK_SIZE])
{
	u_int num;
	AES_KEY key;
	u_char ecount_buf[AES_BLOCK_SIZE] = { 0 };
	int total = 0;

	if (!pInput || !inLen || !ppOutput)
		return -1;

	*ppOutput = e_malloc(inLen);
	if (!*ppOutput) {
		LOGERR;
		return -1;
	} else
		memset(*ppOutput, 0, inLen);

	AES_set_encrypt_key(pKey, 128, &key);

	while (inLen) {
		num = 0;
		memset(ecount_buf, 0, sizeof ecount_buf);
		AES_ctr128_encrypt(pInput + total, (*ppOutput) + total, 
				(inLen / (AES_BLOCK_SIZE - 1)) ? (AES_BLOCK_SIZE - 1) : inLen, 
				&key, IV, ecount_buf, &num);
		if (num < 1) {
			e_free(*ppOutput);
			*ppOutput = NULL;
			total = -1;
			break;
		} else {
			total += num;
			inLen -= num;
		}
	}

	return total;
}