doubango/tinyNET/src/stun/tnet_stun_pkt.c
c732d49e
 #if HAVE_CRT
 #define _CRTDBG_MAP_ALLOC 
 #include <stdlib.h> 
 #include <crtdbg.h>
 #endif //HAVE_CRT
 /*
 * Copyright (C) 2017, University of the Basque Country (UPV/EHU)
 * Contact for licensing options: <licensing-mcpttclient(at)mcopenplatform(dot)com>
 *
 * The original file was part of Open Source Doubango Framework
 * Copyright (C) 2010-2011 Mamadou Diop.
 * Copyright (C) 2012 Doubango Telecom <http://doubango.org>
 *
 * This file is part of Open Source Doubango Framework.
 *
 * DOUBANGO is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * DOUBANGO 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with DOUBANGO.
 *
 */
 #include "stun/tnet_stun_pkt.h"
 #include "stun/tnet_stun_utils.h"
 
 #include "tnet_endianness.h"
 
 #include "tsk_sha1.h"
 #include "tsk_hmac.h"
 #include "tsk_md5.h"
 #include "tsk_ppfcs32.h"
 #include "tsk_buffer.h"
 #include "tsk_string.h"
 #include "tsk_memory.h"
 #include "tsk_debug.h"
 
 #if !defined(PRINT_DESTROYED_MSG)
 #	define PRINT_DESTROYED_MSG	0
 #endif
 
 int tnet_stun_pkt_create(tnet_stun_pkt_type_t e_type, uint16_t u_length, const tnet_stun_transac_id_t* pc_transac_id, tnet_stun_pkt_t** pp_attr)
 {
 	extern const tsk_object_def_t *tnet_stun_pkt_def_t;
 	if (!pp_attr) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	if (!(*pp_attr = tsk_object_new(tnet_stun_pkt_def_t))) {
 		TSK_DEBUG_ERROR("Failed to create STUN pkt object");
 		return -2;
 	}
 	if (!((*pp_attr)->p_list_attrs = tsk_list_create())) {
 		TSK_OBJECT_SAFE_FREE(*pp_attr);
 		return -3;
 	}
 	if (pc_transac_id) {
 		memcpy((*pp_attr)->transac_id, *pc_transac_id, sizeof(tnet_stun_transac_id_t));
 	}
 	else {
 		tnet_stun_utils_transac_id_rand(&(*pp_attr)->transac_id);
 	}
 	(*pp_attr)->e_type = e_type;
 	(*pp_attr)->u_length = u_length;
 	return 0;
 }
 
 int tnet_stun_pkt_attr_add(tnet_stun_pkt_t* p_self, tnet_stun_attr_t** pp_attr)
 {
 	if (!p_self || !pp_attr || !*pp_attr) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	tsk_list_push_back_data(p_self->p_list_attrs, (void**)pp_attr);
 	return 0;
 }
 
 int tnet_stun_pkt_attrs_add(tnet_stun_pkt_t* p_self, ...)
 {
 	va_list ap;
 	int ret = 0;
 	tnet_stun_pkt_attr_add_t e_add_attr;
 	if (!p_self) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	va_start(ap, p_self);
 
 	while ((e_add_attr = va_arg(ap, tnet_stun_pkt_attr_add_t)) != tnet_stun_pkt_attr_add_null) {
 		switch (e_add_attr) {
 		case tnet_stun_pkt_attr_add_vdata: {
 			// (enum tnet_stun_attr_type_e)(E_TYPE), (const uint8_t*)(P_DATA_PTR), (uint16_t)(U_DATA_SIZE)
 			enum tnet_stun_attr_type_e E_TYPE = va_arg(ap, enum tnet_stun_attr_type_e);
 			const uint8_t* P_DATA_PTR = va_arg(ap, const uint8_t*);
 			uint16_t U_DATA_SIZE = tsk_va_arg_u16(ap);
 			tnet_stun_attr_vdata_t *p_attr;
 			if ((ret = tnet_stun_attr_vdata_create(E_TYPE, P_DATA_PTR, U_DATA_SIZE, &p_attr))) {
 				goto bail;
 			}
 			if ((ret = tnet_stun_pkt_attr_add(p_self, (tnet_stun_attr_t**)&p_attr))) {
 				TSK_OBJECT_SAFE_FREE(p_attr);
 				goto bail;
 			}
 			break;
 		}
 		case tnet_stun_pkt_attr_add_address: {
 			// (enum tnet_stun_attr_type_e)(E_TYPE), (enum tnet_stun_address_family_e)(E_FAMILY), (uint16_t)(U_PORT), (const tnet_stun_addr_t*)PC_ADDR_PTR
 			enum tnet_stun_attr_type_e E_TYPE = va_arg(ap, enum tnet_stun_attr_type_e);
 			enum tnet_stun_address_family_e E_FAMILY = va_arg(ap, enum tnet_stun_address_family_e);
 			uint16_t U_PORT = tsk_va_arg_u16(ap);
 			const tnet_stun_addr_t* PC_ADDR_PTR = va_arg(ap, const tnet_stun_addr_t*);
 			tnet_stun_attr_address_t *p_attr;
 			if ((ret = tnet_stun_attr_address_create(E_TYPE, E_FAMILY, U_PORT, PC_ADDR_PTR, &p_attr))) {
 				goto bail;
 			}
 			if ((ret = tnet_stun_pkt_attr_add(p_self, (tnet_stun_attr_t**)&p_attr))) {
 				TSK_OBJECT_SAFE_FREE(p_attr);
 				goto bail;
 			}
 			break;
 		}
 		case tnet_stun_pkt_attr_add_error_code: {
 			// (uint8_t)(U8_CLASS), (uint8_t)(U8_NUMBER), (const char*)(PC_REASON_STR)
 			uint8_t U8_CLASS = tsk_va_arg_u8(ap);
 			uint8_t U8_NUMBER = tsk_va_arg_u8(ap);
 			const char* PC_REASON_STR = va_arg(ap, const char*);
 			tnet_stun_attr_error_code_t *p_attr;
 			if ((ret = tnet_stun_attr_error_code_create(U8_CLASS, U8_NUMBER, PC_REASON_STR, (uint16_t)tsk_strlen(PC_REASON_STR), &p_attr))) {
 				goto bail;
 			}
 			if ((ret = tnet_stun_pkt_attr_add(p_self, (tnet_stun_attr_t**)&p_attr))) {
 				TSK_OBJECT_SAFE_FREE(p_attr);
 				goto bail;
 			}
 			break;
 		}
 		case tnet_stun_pkt_attr_add_unknown_attrs: {
 			// (...)
 			tsk_buffer_t* p_buffer = tsk_buffer_create_null();
 			tnet_stun_attr_vdata_t *p_attr;
 			uint16_t u_16;
 			if (!p_buffer) {
 				TSK_DEBUG_ERROR("Failed to create buffer");
 				ret = -4;
 				goto bail;
 			}
 			while ((e_add_attr = va_arg(ap, tnet_stun_pkt_attr_add_t)) != tnet_stun_pkt_attr_add_null) {
 				if (e_add_attr != tnet_stun_pkt_attr_add_unknown_attrs_val) {
 					TSK_OBJECT_SAFE_FREE(p_buffer);
 					TSK_DEBUG_ERROR("Arguments corrupted or invalid.");
 					ret = -3;
 					goto bail;
 				}
 				u_16 = tsk_va_arg_u16(ap);
 				tsk_buffer_append(p_buffer, &u_16, 2);
 			}
 			if ((ret = tnet_stun_attr_vdata_create(tnet_stun_attr_type_unknown_attrs, p_buffer->data, (uint16_t)p_buffer->size, &p_attr))) {
 				TSK_OBJECT_SAFE_FREE(p_buffer);
 				goto bail;
 			}
 			TSK_OBJECT_SAFE_FREE(p_buffer);
 			if ((ret = tnet_stun_pkt_attr_add(p_self, (tnet_stun_attr_t**)&p_attr))) {
 				TSK_OBJECT_SAFE_FREE(p_attr);
 				goto bail;
 			}
 			break;
 		}
 		default: {
 			TSK_DEBUG_ERROR("Arguments corrupted or invalid.");
 			ret = -2;
 			goto bail;
 		}
 		}
 	}
 
 bail:
 	va_end(ap);
 	return ret;
 }
 
 int tnet_stun_pkt_attr_remove(struct tnet_stun_pkt_s* p_self, enum tnet_stun_attr_type_e e_type)
 {
 	tsk_list_item_t* pc_item;
 	tnet_stun_attr_t* pc_attr;
 	if (!p_self || !p_self->p_list_attrs) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 
 again:
 	tsk_list_foreach(pc_item, p_self->p_list_attrs) {
 		if ((pc_attr = (tnet_stun_attr_t*)pc_item->data)) {
 			if (pc_attr->hdr.e_type == e_type) {
 				tsk_list_remove_item(p_self->p_list_attrs, pc_item);
 				goto again;
 			}
 		}
 	}
 	return 0;
 }
 
 int tnet_stun_pkt_attr_find(const tnet_stun_pkt_t* pc_self, tnet_stun_attr_type_t e_type, tsk_size_t u_index, const tnet_stun_attr_t** ppc_attr)
 {
 	const tsk_list_item_t* pc_item;
 	const tnet_stun_attr_t* pc_attr;
 	if (!pc_self || !ppc_attr) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	*ppc_attr = tsk_null;
 	tsk_list_foreach(pc_item, pc_self->p_list_attrs) {
 		if ((pc_attr = (const tnet_stun_attr_t*)pc_item->data)) {
 			if (pc_attr->hdr.e_type == e_type && !u_index--) {
 				*ppc_attr = pc_attr;
 				break;
 			}
 		}
 	}
 	return 0;
 }
 
 tsk_bool_t tnet_stun_pkt_attr_exists(const tnet_stun_pkt_t* pc_self, tnet_stun_attr_type_t e_type)
 {
 	const tnet_stun_attr_t* pc_attr;
 	int ret = tnet_stun_pkt_attr_find(pc_self, e_type, 0, &pc_attr);
 	return (pc_attr && (ret == 0));
 }
 
 int tnet_stun_pkt_get_size_in_octetunits_without_padding(const  tnet_stun_pkt_t* pc_self, tsk_size_t* p_size)
 {
 	const tsk_list_item_t* pc_item;
 	const tnet_stun_attr_t* pc_attr;
 	tsk_size_t n_size;
 	int ret;
 	if (!pc_self || !p_size) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	*p_size = kStunPktHdrSizeInOctets;
 	tsk_list_foreach(pc_item, pc_self->p_list_attrs) {
 		if ((pc_attr = (const tnet_stun_attr_t*)pc_item->data)) {
 			if ((ret = tnet_stun_attr_get_size_in_octetunits_without_padding(pc_attr, &n_size))) {
 				return ret;
 			}
 			*p_size += n_size;
 		}
 	}
 	if (pc_self->opt.fingerprint) {
 		*p_size += kStunAttrHdrSizeInOctets + 4;
 	}
 	if (pc_self->opt.dontfrag) {
 		*p_size += kStunAttrHdrSizeInOctets;
 	}
 	return 0;
 }
 
 int tnet_stun_pkt_get_size_in_octetunits_with_padding(const  tnet_stun_pkt_t* pc_self, tsk_size_t* p_size)
 {
 	const tsk_list_item_t* pc_item;
 	const tnet_stun_attr_t* pc_attr;
 	tsk_size_t n_size;
 	int ret;
 	if (!pc_self || !p_size) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	*p_size = kStunPktHdrSizeInOctets;
 	tsk_list_foreach(pc_item, pc_self->p_list_attrs) {
 		if ((pc_attr = (const tnet_stun_attr_t*)pc_item->data)) {
 			if ((ret = tnet_stun_attr_get_size_in_octetunits_with_padding(pc_attr, &n_size))) {
 				return ret;
 			}
 			*p_size += n_size;
 		}
 	}
 	if (pc_self->opt.fingerprint) {
 		*p_size += kStunAttrHdrSizeInOctets + 4;
 	}
 	if (pc_self->opt.dontfrag) {
 		*p_size += kStunAttrHdrSizeInOctets;
 	}
 	return 0;
 }
 
 int tnet_stun_pkt_write_with_padding(const tnet_stun_pkt_t* pc_self, uint8_t* p_buff_ptr, tsk_size_t n_buff_size, tsk_size_t *p_written)
 {
 	const tsk_list_item_t* pc_item;
 	const tnet_stun_attr_t* pc_attr;
 	tsk_size_t n_size;
 	int ret;
 	uint8_t *_p_buff_ptr = p_buff_ptr, *_p_msg_int_start;
 	if (!pc_self || !p_buff_ptr || !n_buff_size || !p_written) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	if ((ret = tnet_stun_pkt_get_size_in_octetunits_with_padding(pc_self, p_written))) {
 		return ret;
 	}
 	if ((n_buff_size < *p_written)) {
 		TSK_DEBUG_ERROR("Buffer too short: %u<%u", n_buff_size, *p_written);
 		return -1;
 	}
 
 	// write header
 	*((uint16_t*)&p_buff_ptr[0]) = tnet_htons((unsigned short)pc_self->e_type);
 	*((uint32_t*)&p_buff_ptr[4]) = (uint32_t)tnet_htonl(kStunMagicCookie);
 	memcpy(&p_buff_ptr[8], pc_self->transac_id, sizeof(pc_self->transac_id));
 
 	p_buff_ptr += kStunPktHdrSizeInOctets;
 	n_buff_size -= kStunPktHdrSizeInOctets;
 
 	// write attributes
 	tsk_list_foreach(pc_item, pc_self->p_list_attrs) {
 		if ((pc_attr = (const tnet_stun_attr_t*)pc_item->data)) {
 			if ((pc_attr->hdr.e_type == tnet_stun_attr_type_message_integrity)) {
 				continue; // because 'MESSAGE-INTEGRITY' must be the latest attribute
 			}
 			if ((ret = tnet_stun_attr_write_with_padding(&pc_self->transac_id, pc_attr, p_buff_ptr, n_buff_size, &n_size))) {
 				return ret;
 			}
 			p_buff_ptr += n_size;
 			n_buff_size -= n_size;
 		}
 	}
 
 	// DONT-FRAGMENT
 	if (pc_self->opt.dontfrag && tnet_stun_pkt_attr_find_first(pc_self, tnet_stun_attr_type_dont_fragment, &pc_attr) == 0 && !pc_attr) {
 		*((uint16_t*)&p_buff_ptr[0]) = tnet_htons(tnet_stun_attr_type_dont_fragment); // Type
 		*((uint16_t*)&p_buff_ptr[2]) = 0; // Length
 		p_buff_ptr += 4;
 	}
 
 	// MESSAGE-INTEGRITY
 	if (!tsk_strnullORempty(pc_self->p_pwd) && tnet_stun_pkt_attr_find_first(pc_self, tnet_stun_attr_type_message_integrity, &pc_attr) == 0 && pc_attr) {
 		/* RFC 5389 - 15.4.  MESSAGE-INTEGRITY
 		   The MESSAGE-INTEGRITY attribute contains an HMAC-SHA1 [RFC2104] of the STUN message.
 
 		   For long-term credentials ==> key = MD5(username ":" realm ":" SASLprep(password))
 		   For short-term credentials ==> key = SASLprep(password)
 		   */
 
 		tsk_sha1digest_t hmac;
 		const tnet_stun_attr_vdata_t *pc_attr_username = tsk_null, *pc_attr_realm = tsk_null, *pc_attr_nonce = tsk_null;
 		static const uint16_t kMsgIntTotalLength = kStunAttrHdrSizeInOctets + TSK_SHA1_DIGEST_SIZE;
 		_p_msg_int_start = p_buff_ptr;
 
 		// write attribute
 		if ((ret = tnet_stun_attr_write_with_padding(&pc_self->transac_id, pc_attr, p_buff_ptr, n_buff_size, &n_size))) {
 			return ret;
 		}
 		p_buff_ptr += n_size;
 		n_buff_size -= n_size;
 
 		// Length (must be correct before computing message integrity)
 		*((uint16_t*)&_p_buff_ptr[2]) = tnet_htons((unsigned short)((p_buff_ptr - _p_buff_ptr) - kStunPktHdrSizeInOctets));
 
 		if ((ret = tnet_stun_pkt_attr_find_first(pc_self, tnet_stun_attr_type_username, (const tnet_stun_attr_t**)&pc_attr_username))) {
 			return ret;
 		}
 		if (pc_attr_username) {
 			if ((ret = tnet_stun_pkt_attr_find_first(pc_self, tnet_stun_attr_type_realm, (const tnet_stun_attr_t**)&pc_attr_realm))) {
 				return ret;
 			}
 			if (pc_attr_realm) {
 				if ((ret = tnet_stun_pkt_attr_find_first(pc_self, tnet_stun_attr_type_nonce, (const tnet_stun_attr_t**)&pc_attr_nonce))) {
 					return ret;
 				}
 			}
 		}
 		if (pc_attr_username && pc_attr_realm && pc_attr_nonce) {
 			// LONG-TERM
 			char* p_keystr = tsk_null;
 			tsk_md5digest_t md5;
 			tsk_sprintf(&p_keystr, "%s:%s:%s", pc_attr_username->p_data_ptr, pc_attr_realm->p_data_ptr, pc_self->p_pwd);
 			TSK_MD5_DIGEST_CALC(p_keystr, (tsk_size_t)tsk_strlen(p_keystr), md5);
 			hmac_sha1digest_compute(_p_buff_ptr, (tsk_size_t)(_p_msg_int_start - _p_buff_ptr), (const char*)md5, TSK_MD5_DIGEST_SIZE, hmac);
 			TSK_FREE(p_keystr);
 		}
 		else {
 			// SHORT-TERM
 			hmac_sha1digest_compute(_p_buff_ptr, (tsk_size_t)(_p_msg_int_start - _p_buff_ptr), pc_self->p_pwd, (tsk_size_t)tsk_strlen(pc_self->p_pwd), hmac);
 		}
 
 		// update MESSAGE-INTEGRITY attribute value
 		if ((ret = tnet_stun_attr_vdata_update((tnet_stun_attr_vdata_t*)pc_attr, hmac, TSK_SHA1_DIGEST_SIZE))) {
 			return ret;
 		}
 		if ((ret = tnet_stun_attr_write_with_padding(&pc_self->transac_id, pc_attr, _p_msg_int_start, kMsgIntTotalLength, &n_size))) {
 			return ret;
 		}
 	}
 
 	// Length before computing FINGERPRINT
 	*((uint16_t*)&_p_buff_ptr[2]) = tnet_htons((unsigned short)((p_buff_ptr - _p_buff_ptr) - kStunPktHdrSizeInOctets + ((pc_self->opt.fingerprint && (p_buff_ptr - _p_buff_ptr) >= 8) ? 8 : 0)));
 
 	if (pc_self->opt.fingerprint && (p_buff_ptr - _p_buff_ptr) >= 8) {
 		/*	RFC 5389 - 15.5.  FINGERPRINT
 			The FINGERPRINT attribute MAY be present in all STUN messages.  The
 			value of the attribute is computed as the CRC-32 of the STUN message
 			up to (but excluding) the FINGERPRINT attribute itself, XOR'ed with
 			the 32-bit value 0x5354554e
 			*/
 		uint32_t u_fingerprint = tsk_pppfcs32(TSK_PPPINITFCS32, _p_buff_ptr, (int32_t)(p_buff_ptr - _p_buff_ptr)) ^ kStunFingerprintXorConst;
 		*((uint16_t*)&p_buff_ptr[0]) = tnet_htons(tnet_stun_attr_type_fingerprint); // Type
 		*((uint16_t*)&p_buff_ptr[2]) = tnet_htons(4); // Length
 		*((uint32_t*)&p_buff_ptr[4]) = (uint32_t)tnet_htonl(u_fingerprint);
 		p_buff_ptr += 8;
 	}
 
 	*p_written = (tsk_size_t)(p_buff_ptr - _p_buff_ptr);
 	return 0;
 }
 
 int tnet_stun_pkt_write_with_padding_2(const struct tnet_stun_pkt_s* pc_self, struct tsk_buffer_s** pp_buff)
 {
 	tsk_size_t u_buff_size;
 	int ret;
 	if (!pc_self || !pp_buff) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	*pp_buff = tsk_null;
 	if ((ret = tnet_stun_pkt_get_size_in_octetunits_with_padding(pc_self, &u_buff_size))) {
 		goto bail;
 	}
 	u_buff_size += kStunBuffMinPad;
 	if (!(*pp_buff = tsk_buffer_create(tsk_null, u_buff_size))) {
 		goto bail;
 	}
 	if ((ret = tnet_stun_pkt_write_with_padding(pc_self, (*pp_buff)->data, (*pp_buff)->size, &(*pp_buff)->size))) {
 		goto bail;
 	}
 bail:
 	if (ret) {
 		TSK_OBJECT_SAFE_FREE(*pp_buff);
 	}
 	return ret;
 }
 
 int tnet_stun_pkt_is_complete(const uint8_t* pc_buff_ptr, tsk_size_t n_buff_size, tsk_bool_t *pb_is_complete)
 {
 	if (!pb_is_complete) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	*pb_is_complete = tsk_false;
 	if (pc_buff_ptr && n_buff_size >= kStunPktHdrSizeInOctets) {
 		tsk_size_t n_paylen_in_octets = tnet_ntohs_2(&pc_buff_ptr[2]);
 		*pb_is_complete = ((n_buff_size - kStunPktHdrSizeInOctets) >= n_paylen_in_octets);
 	}
 	return 0;
 }
 
 int tnet_stun_pkt_read(const uint8_t* pc_buff_ptr, tsk_size_t n_buff_size, tnet_stun_pkt_t** pp_pkt)
 {
 	tsk_bool_t b_is_complete;
 	uint16_t PayloadLengthInOctets;
 	tnet_stun_pkt_type_t Type;
 	tnet_stun_transac_id_t transac_id;
 	uint32_t MagicCookie;
 	int ret;
 
 	if (!pc_buff_ptr || !n_buff_size || !pp_pkt) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	if (!TNET_STUN_BUFF_IS_STUN2(pc_buff_ptr, n_buff_size)) {
 		TSK_DEBUG_ERROR("Buffer doesn't contain a valid STUN2 pkt");
 		return -2;
 	}
 	if ((ret = tnet_stun_pkt_is_complete(pc_buff_ptr, n_buff_size, &b_is_complete))) {
 		return ret;
 	}
 	if (!b_is_complete) {
 		TSK_DEBUG_ERROR("Buffer too short(%u)", n_buff_size);
 		return -3;
 	}
 
 	// read the header
 	Type = tnet_ntohs_2(&pc_buff_ptr[0]);
 	PayloadLengthInOctets = tnet_ntohs_2(&pc_buff_ptr[2]);
 	MagicCookie = (uint32_t)tnet_ntohl_2(&pc_buff_ptr[4]);
 	if (MagicCookie != kStunMagicCookieLong) {
 		TSK_DEBUG_ERROR("%x not a valid STUN2 magic cookie", MagicCookie);
 		return -4;
 	}
 	memcpy(transac_id, &pc_buff_ptr[8], sizeof(tnet_stun_transac_id_t));
 	// create the pkt
 	if ((ret = tnet_stun_pkt_create(Type, PayloadLengthInOctets, (const tnet_stun_transac_id_t*)&transac_id, pp_pkt))) {
 		return ret;
 	}
 
 	if (PayloadLengthInOctets > 0) {
 		tnet_stun_attr_t* p_attr;
 		tsk_size_t n_consumed_octets;
 		pc_buff_ptr += kStunPktHdrSizeInOctets;
 		do {
 			if ((ret = tnet_stun_attr_read((const tnet_stun_transac_id_t*)&(*pp_pkt)->transac_id, pc_buff_ptr, PayloadLengthInOctets, &n_consumed_octets, &p_attr))) {
 				return ret;
 			}
 			if ((ret = tnet_stun_pkt_attr_add((*pp_pkt), &p_attr))) {
 				TSK_OBJECT_SAFE_FREE((*pp_pkt));
 				return ret;
 			}
 			PayloadLengthInOctets -= (uint16_t)n_consumed_octets;
 			pc_buff_ptr += n_consumed_octets;
 		} while (PayloadLengthInOctets >= kStunAttrHdrSizeInOctets);
 	}
 
 	return 0;
 }
 
 int tnet_stun_pkt_auth_prepare(tnet_stun_pkt_t* p_self, const char* pc_usr_name, const char* pc_pwd, const char* pc_realm, const char* pc_nonce)
 {
 	const tnet_stun_attr_t* pc_attr;
 	int ret;
 	static const tsk_sha1digest_t __pc_sha1digestEmpty = { 0 };
 	static const uint16_t __u_sha1digestEmpty = sizeof(__pc_sha1digestEmpty);
 	if (!p_self /*|| !pc_usr_name*/ || !pc_pwd /*|| !pc_realm || !pc_nonce*/) { // "username", "realm" and "nonce" are null for short-term authentication
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	// USERNAME
 	if (pc_usr_name) { // LONG-TERM, optional for SHORT-TERM
 		if ((ret = tnet_stun_pkt_attr_find_first(p_self, tnet_stun_attr_type_username, &pc_attr))) {
 			goto bail;
 		}
 		if (pc_attr) {
 			if ((ret = tnet_stun_attr_vdata_update((tnet_stun_attr_vdata_t*)pc_attr, (const uint8_t*)pc_usr_name, (uint16_t)tsk_strlen(pc_usr_name)))) {
 				goto bail;
 			}
 		}
 		else {
 			ret = tnet_stun_pkt_attrs_add(p_self,
 				TNET_STUN_PKT_ATTR_ADD_USERNAME_ZT(pc_usr_name),
 				TNET_STUN_PKT_ATTR_ADD_NULL());
 			if (ret) {
 				goto bail;
 			}
 		}
 	}
 	// REALM
 	if (pc_realm) { // LONG-TERM
 		if ((ret = tnet_stun_pkt_attr_find_first(p_self, tnet_stun_attr_type_realm, &pc_attr))) {
 			goto bail;
 		}
 		if (pc_attr) {
 			if ((ret = tnet_stun_attr_vdata_update((tnet_stun_attr_vdata_t*)pc_attr, (const uint8_t*)pc_realm, (uint16_t)tsk_strlen(pc_realm)))) {
 				goto bail;
 			}
 		}
 		else {
 			ret = tnet_stun_pkt_attrs_add(p_self,
 				TNET_STUN_PKT_ATTR_ADD_REALM_ZT(pc_realm),
 				TNET_STUN_PKT_ATTR_ADD_NULL());
 			if (ret) {
 				goto bail;
 			}
 		}
 	}
 	// NONCE
 	if (pc_nonce) { // LONG-TERM
 		if ((ret = tnet_stun_pkt_attr_find_first(p_self, tnet_stun_attr_type_nonce, &pc_attr))) {
 			goto bail;
 		}
 		if (pc_attr) {
 			if ((ret = tnet_stun_attr_vdata_update((tnet_stun_attr_vdata_t*)pc_attr, (const uint8_t*)pc_nonce, (uint16_t)tsk_strlen(pc_nonce)))) {
 				goto bail;
 			}
 		}
 		else {
 			ret = tnet_stun_pkt_attrs_add(p_self,
 				TNET_STUN_PKT_ATTR_ADD_NONCE_ZT(pc_nonce),
 				TNET_STUN_PKT_ATTR_ADD_NULL());
 			if (ret) {
 				goto bail;
 			}
 		}
 	}
 	// MESSAGE-INTEGRITY
 	if ((ret = tnet_stun_pkt_attr_find_first(p_self, tnet_stun_attr_type_message_integrity, &pc_attr))) {
 		goto bail;
 	}
 	if (!pc_attr) {
 		ret = tnet_stun_pkt_attrs_add(p_self,
 			TNET_STUN_PKT_ATTR_ADD_MESSAGE_INTEGRITY(__pc_sha1digestEmpty, __u_sha1digestEmpty),
 			TNET_STUN_PKT_ATTR_ADD_NULL());
 		if (ret) {
 			goto bail;
 		}
 	}
 
 	// PASSWORD
 	tsk_strupdate(&p_self->p_pwd, pc_pwd);
 
 bail:
 	return ret;
 }
 
 // pc_resp = 401 or 438
 int tnet_stun_pkt_auth_prepare_2(struct tnet_stun_pkt_s* p_self, const char* pc_usr_name, const char* pc_pwd, const struct tnet_stun_pkt_s* pc_resp)
 {
 	const tnet_stun_attr_vdata_t* pc_attr;
 	const char *pc_nonce, *pc_realm;
 	int ret;
 	if (!p_self || !pc_usr_name || !pc_pwd || !pc_resp) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 
 	// NONCE
 	if ((ret = tnet_stun_pkt_attr_find_first(pc_resp, tnet_stun_attr_type_nonce, (const tnet_stun_attr_t**)&pc_attr))) {
 		goto bail;
 	}
 	if (!pc_attr || !pc_attr->p_data_ptr || !pc_attr->u_data_size) {
 		TSK_DEBUG_ERROR("Invalid NONCE in 401");
 		ret = -3;
 		goto bail;
 	}
 	pc_nonce = (const char*)pc_attr->p_data_ptr;
 	// REALM
 	if ((ret = tnet_stun_pkt_attr_find_first(pc_resp, tnet_stun_attr_type_realm, (const tnet_stun_attr_t**)&pc_attr))) {
 		goto bail;
 	}
 	if (!pc_attr || !pc_attr->p_data_ptr || !pc_attr->u_data_size) {
 		TSK_DEBUG_ERROR("Invalid REALM in 401");
 		ret = -3;
 		goto bail;
 	}
 	pc_realm = (const char*)pc_attr->p_data_ptr;
 
 	if ((ret = tnet_stun_pkt_auth_prepare(p_self, pc_usr_name, pc_pwd, pc_realm, pc_nonce))) {
 		goto bail;
 	}
 
 	// TRANSACTION-ID
 	if ((ret = tnet_stun_utils_transac_id_rand(&p_self->transac_id))) {
 		goto bail;
 	}
 
 bail:
 	return ret;
 }
 
 int tnet_stun_pkt_auth_copy(tnet_stun_pkt_t* p_self, const char* pc_usr_name, const char* pc_pwd, const tnet_stun_pkt_t* pc_pkt)
 {
 	const tnet_stun_attr_vdata_t *pc_attr_realm = tsk_null, *pc_attr_nonce = tsk_null;
 	int ret;
 	tsk_bool_t b_ok;
 	if (!p_self || !pc_pwd || !pc_usr_name || !pc_pkt) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 
 	b_ok =
 		(ret = tnet_stun_pkt_attr_find_first(pc_pkt, tnet_stun_attr_type_realm, (const tnet_stun_attr_t**)&pc_attr_realm)) == 0 && pc_attr_realm
 		&& (ret = tnet_stun_pkt_attr_find_first(pc_pkt, tnet_stun_attr_type_nonce, (const tnet_stun_attr_t**)&pc_attr_nonce)) == 0 && pc_attr_nonce;
 
 	if (b_ok && (ret = tnet_stun_pkt_auth_prepare(p_self, pc_usr_name, pc_pwd, (const char*)pc_attr_realm->p_data_ptr, (const char*)pc_attr_nonce->p_data_ptr))) {
 		goto bail;
 	}
 
 bail:
 	return ret;
 }
 
 int tnet_stun_pkt_get_errorcode(const struct tnet_stun_pkt_s* pc_self, uint16_t* pu_code)
 {
 	const tnet_stun_attr_error_code_t* pc_attr;
 	int ret;
 	if (!pc_self && !pu_code) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	*pu_code = 0;
 	if ((ret = tnet_stun_pkt_attr_find_first(pc_self, tnet_stun_attr_type_error_code, (const tnet_stun_attr_t**)&pc_attr))) {
 		return ret;
 	}
 	if (pc_attr) {
 		*pu_code = (pc_attr->u_class * 100) + pc_attr->u_number;
 	}
 	return 0;
 }
 
 int tnet_stun_pkt_process_err420(struct tnet_stun_pkt_s *p_self, const struct tnet_stun_pkt_s *pc_pkt_resp420)
 {
 	const tnet_stun_attr_vdata_t* pc_attr;
 	uint16_t u16;
 	int ret;
 	tsk_bool_t b_done = tsk_false;
 	if (!p_self || !pc_pkt_resp420) {
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 	if ((ret = tnet_stun_pkt_attr_find_first(pc_pkt_resp420, tnet_stun_attr_type_unknown_attrs, (const tnet_stun_attr_t**)&pc_attr))) {
 		goto bail;
 	}
 	if (!pc_attr || !pc_attr->p_data_ptr || (pc_attr->u_data_size & 1)) {
 		TSK_DEBUG_ERROR("UNKNOWN-ATTRIBUTES missing in 420");
 		ret = -3;
 		goto bail;
 	}
 	for (u16 = 0; u16 < pc_attr->u_data_size; u16 += 2) {
 		switch (*((uint16_t*)&pc_attr->p_data_ptr[u16])) {
 		case tnet_stun_attr_type_dont_fragment: {
 			p_self->opt.dontfrag = 0;
 			b_done = tsk_true;
 			break;
 		}
 		case tnet_stun_attr_type_fingerprint: {
 			p_self->opt.fingerprint = 0;
 			b_done = tsk_true;
 			break;
 		}
 		}
 	}
 
 	if (b_done) {
 		// TRANSACTION-ID
 		if ((ret = tnet_stun_utils_transac_id_rand(&p_self->transac_id))) {
 			goto bail;
 		}
 	}
 
 bail:
 	return ret;
 }
 
 static tsk_object_t* tnet_stun_pkt_ctor(tsk_object_t * self, va_list * app)
 {
 	tnet_stun_pkt_t *p_pkt = (tnet_stun_pkt_t *)self;
 	if (p_pkt) {
 		p_pkt->opt.fingerprint = kStunOptFingerPrint;
 		p_pkt->opt.dontfrag = kStunOptDontFragment;
 	}
 	return self;
 }
 static tsk_object_t* tnet_stun_pkt_dtor(tsk_object_t * self)
 {
 	tnet_stun_pkt_t *p_pkt = (tnet_stun_pkt_t *)self;
 	if (p_pkt) {
 #if PRINT_DESTROYED_MSG
 		TSK_DEBUG_INFO("*** STUN pkt destroyed ***");
 #endif
 		TSK_OBJECT_SAFE_FREE(p_pkt->p_list_attrs);
 		TSK_FREE(p_pkt->p_pwd);
 	}
 	return self;
 }
 static const tsk_object_def_t tnet_stun_pkt_def_s = {
 	sizeof(tnet_stun_pkt_t),
 	tnet_stun_pkt_ctor,
 	tnet_stun_pkt_dtor,
 	tsk_null,
 };
 const tsk_object_def_t *tnet_stun_pkt_def_t = &tnet_stun_pkt_def_s;