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/*
Copyright (C) 2006-2007 Werner Dittmann
This program 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.
This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Authors: Werner Dittmann <Werner.Dittmann@t-online.de>
*/
#include <libzrtpcpp/ZrtpPacketHello.h>
ZrtpPacketHello::ZrtpPacketHello() {
DEBUGOUT((fprintf(stdout, "Creating Hello packet without data\n")));
}
void ZrtpPacketHello::configureHello(ZrtpConfigure* config) {
// The NumSupported* data is in ZrtpTextData.h
nHash = config->getNumConfiguredAlgos(HashAlgorithm);
nCipher = config->getNumConfiguredAlgos(CipherAlgorithm);
nPubkey = config->getNumConfiguredAlgos(PubKeyAlgorithm);
nSas = config->getNumConfiguredAlgos(SasType);
nAuth = config->getNumConfiguredAlgos(AuthLength);
// length is fixed Header plus HMAC size (2*ZRTP_WORD_SIZE)
int32_t length = sizeof(HelloPacket_t) + (2 * ZRTP_WORD_SIZE);
length += nHash * ZRTP_WORD_SIZE;
length += nCipher * ZRTP_WORD_SIZE;
length += nPubkey * ZRTP_WORD_SIZE;
length += nSas * ZRTP_WORD_SIZE;
length += nAuth * ZRTP_WORD_SIZE;
// Don't change order of this sequence
oHash = sizeof(Hello_t);
oCipher = oHash + (nHash * ZRTP_WORD_SIZE);
oAuth = oCipher + (nCipher * ZRTP_WORD_SIZE);
oPubkey = oAuth + (nAuth * ZRTP_WORD_SIZE);
oSas = oPubkey + (nPubkey * ZRTP_WORD_SIZE);
oHmac = oSas + (nSas * ZRTP_WORD_SIZE); // offset to HMAC
void* allocated = &data;
memset(allocated, 0, sizeof(data));
zrtpHeader = (zrtpPacketHeader_t *)&((HelloPacket_t *)allocated)->hdr; // the standard header
helloHeader = (Hello_t *)&((HelloPacket_t *)allocated)->hello;
setZrtpId();
// minus 1 for CRC size
setLength(length / ZRTP_WORD_SIZE);
setMessageType((uint8_t*)HelloMsg);
setVersion((uint8_t*)zrtpVersion);
uint32_t lenField = nHash << 16;
for (int32_t i = 0; i < nHash; i++) {
AlgorithmEnum& hash = config->getAlgoAt(HashAlgorithm, i);
setHashType(i, (int8_t*)hash.getName());
}
lenField |= nCipher << 12;
for (int32_t i = 0; i < nCipher; i++) {
AlgorithmEnum& cipher = config->getAlgoAt(CipherAlgorithm, i);
setCipherType(i, (int8_t*)cipher.getName());
}
lenField |= nAuth << 8;
for (int32_t i = 0; i < nAuth; i++) {
AlgorithmEnum& length = config->getAlgoAt(AuthLength, i);
setAuthLen(i, (int8_t*)length.getName());
}
lenField |= nPubkey << 4;
for (int32_t i = 0; i < nPubkey; i++) {
AlgorithmEnum& pubKey = config->getAlgoAt(PubKeyAlgorithm, i);
setPubKeyType(i, (int8_t*)pubKey.getName());
}
lenField |= nSas;
for (int32_t i = 0; i < nSas; i++) {
AlgorithmEnum& sas = config->getAlgoAt(SasType, i);
setSasType(i, (int8_t*)sas.getName());
}
*((uint32_t*)&helloHeader->flags) = htonl(lenField);
}
ZrtpPacketHello::ZrtpPacketHello(uint8_t *data) {
DEBUGOUT((fprintf(stdout, "Creating Hello packet from data\n")));
zrtpHeader = (zrtpPacketHeader_t *)&((HelloPacket_t *)data)->hdr; // the standard header
helloHeader = (Hello_t *)&((HelloPacket_t *)data)->hello;
uint32_t t = *((uint32_t*)&helloHeader->flags);
uint32_t temp = ntohl(t);
nHash = (temp & (0xf << 16)) >> 16;
nHash &= 0x7; // restrict to max 7 algorithms
nCipher = (temp & (0xf << 12)) >> 12;
nCipher &= 0x7;
nAuth = (temp & (0xf << 8)) >> 8;
nAuth &= 0x7;
nPubkey = (temp & (0xf << 4)) >> 4;
nPubkey &= 0x7;
nSas = temp & 0xf;
nSas &= 0x7;
oHash = sizeof(Hello_t);
oCipher = oHash + (nHash * ZRTP_WORD_SIZE);
oAuth = oCipher + (nCipher * ZRTP_WORD_SIZE);
oPubkey = oAuth + (nAuth * ZRTP_WORD_SIZE);
oSas = oPubkey + (nPubkey * ZRTP_WORD_SIZE);
oHmac = oSas + (nSas * ZRTP_WORD_SIZE); // offset to HMAC
}
ZrtpPacketHello::~ZrtpPacketHello() {
DEBUGOUT((fprintf(stdout, "Deleting Hello packet: alloc: %x\n", allocated)));
}
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