#include "commonheaders.h"

// generate KeyA pair and return public key
LPSTR InitKeyA(pUinKey ptr,int features)
{
	Sent_NetLog("InitKeyA: %04x", features);

	if (!ptr->cntx )
		ptr->cntx = cpp_create_context(isProtoSmallPackets(ptr->hContact)?CPP_MODE_BASE64:0);

	char *tmp = db_get_sa(ptr->hContact,MODULENAME,"PSK");
	if (tmp) {
		cpp_init_keyp(ptr->cntx,tmp);	// make pre-shared key from password
		mir_free(tmp);
	}

	LPSTR pub_text = cpp_init_keya(ptr->cntx,features);	// calculate public and private key & fill KeyA

	LPSTR keysig;
	if (features&CPP_FEATURES_NEWPG) {
		if (features&KEY_B_SIG)
			keysig = (LPSTR)SIG_KEYB;
		else
			keysig = (LPSTR)SIG_KEYA;
	}
	else if (isProtoSmallPackets(ptr->hContact))
		keysig = (LPSTR)SIG_KEY4;
	else
		keysig = (LPSTR)SIG_KEY3;

	int slen = (int)strlen(keysig);
	int tlen = (int)strlen(pub_text);

	LPSTR keyToSend = (LPSTR) mir_alloc(slen+tlen+1);

	memcpy(keyToSend,keysig,slen);
	memcpy(keyToSend+slen,pub_text,tlen+1);

	return keyToSend;
}

// store KeyB into context
int InitKeyB(pUinKey ptr,LPCSTR key)
{
	Sent_NetLog("InitKeyB: %s", key);

	if (!ptr->cntx)
		ptr->cntx = cpp_create_context(isProtoSmallPackets(ptr->hContact)?CPP_MODE_BASE64:0);

	if (!cpp_keyp(ptr->cntx)) {
		char *tmp = db_get_sa(ptr->hContact,MODULENAME,"PSK");
		if (tmp) {
		    cpp_init_keyp(ptr->cntx,tmp);	// make pre-shared key from password
		    mir_free(tmp);
		}
	}

	cpp_init_keyb(ptr->cntx,key);
	ptr->features = cpp_get_features(ptr->cntx);

	return cpp_get_error(ptr->cntx);
}


// store KeyX into context
void InitKeyX(pUinKey ptr,BYTE *key)
{
	if (!ptr->cntx)
		ptr->cntx = cpp_create_context(isProtoSmallPackets(ptr->hContact)?CPP_MODE_BASE64:0);

	cpp_set_keyx(ptr->cntx,key);
}


// calculate secret key
BOOL CalculateKeyX(pUinKey ptr,MCONTACT hContact)
{
	int agr = cpp_calc_keyx(ptr->cntx);
	if (agr) {
		// do this only if key exchanged is ok
		// we use a 192bit key
		int keysize = cpp_size_keyx();
		PBYTE buffer = (PBYTE) alloca(keysize); // buffer for hash

		// store key
		cpp_get_keyx(ptr->cntx,buffer);

		// store key in database
		db_set_blob(hContact, MODULENAME, "offlineKey", buffer, keysize);

		// store timeout of key in database (2 days)
		db_set_dw(hContact, MODULENAME, "offlineKeyTimeout", gettime()+(60*60*24*db_get_w(0,MODULENAME,"okt",2)));

		// key exchange is finished
		showPopupEC(ptr->hContact);
	}
	else {
		// agree value problem
		showPopup(sim002,hContact,g_hPOP[POP_PU_DIS],0);
	}
	return agr != 0;
}


// encrypt message
LPSTR encrypt(pUinKey ptr, LPCSTR szEncMsg)
{
	LPSTR szSig = (LPSTR) (ptr->offlineKey?SIG_ENOF:SIG_ENON);

	int slen = (int)strlen(szSig);
	int clen = (int)strlen(szEncMsg);

	LPSTR szMsg = (LPSTR) mir_alloc(clen+slen+1);
	memcpy(szMsg, szSig, slen);
	memcpy(szMsg+slen, szEncMsg, clen+1);

	return szMsg;
}


// encode message
LPSTR encodeMsg(pUinKey ptr, LPARAM lParam)
{
	CCSDATA *pccsd = (CCSDATA *)lParam;
	LPSTR szNewMsg = NULL;
	LPSTR szOldMsg = (LPSTR) pccsd->lParam;

	if (pccsd->wParam & PREF_UTF )
		szNewMsg = encrypt(ptr,cpp_encodeU(ptr->cntx,szOldMsg));
	else if (pccsd->wParam & PREF_UNICODE )
		szNewMsg = encrypt(ptr,cpp_encodeW(ptr->cntx,(LPWSTR)(szOldMsg+strlen(szOldMsg)+1)));
	else
		szNewMsg = encrypt(ptr,cpp_encodeA(ptr->cntx,szOldMsg));

	pccsd->wParam &= ~PREF_UNICODE;
	return szNewMsg;
}


// decode message
LPSTR decodeMsg(pUinKey ptr, LPARAM lParam, LPSTR szEncMsg)
{
	CCSDATA *pccsd = (CCSDATA *)lParam;
	PROTORECVEVENT *ppre = (PROTORECVEVENT *)pccsd->lParam;

	LPSTR szNewMsg = NULL;
	LPSTR szOldMsg = (ppre->flags&PREF_UTF)?cpp_decodeU(ptr->cntx,szEncMsg):cpp_decode(ptr->cntx,szEncMsg);

	if (szOldMsg == NULL) {
		ptr->decoded = false;
		switch(cpp_get_error(ptr->cntx)) {
		case CPP_ERROR_BAD_LEN:
			szNewMsg = mir_strdup(Translate(sim102));
			break;
		case CPP_ERROR_BAD_CRC:
			szNewMsg = mir_strdup(Translate(sim103));
			break;
		default:
			ptr->decoded=true;
			szNewMsg = mir_strdup(Translate(sim101));
			break;
		}
		ppre->flags &= ~(PREF_UNICODE|PREF_UTF);
		pccsd->wParam &= ~(PREF_UNICODE|PREF_UTF);
	}
	else {
		ptr->decoded=true;
		if (ppre->flags & PREF_UTF) { // если протокол поддерживает utf8 - тогда отправляем в utf8
			int olen = (int)strlen(szOldMsg)+1;
			szNewMsg = (LPSTR) mir_alloc(olen);
			memcpy(szNewMsg,szOldMsg,olen);
		}
		else {
			int olen = ((int)strlen(szOldMsg)+1)*(sizeof(WCHAR)+1);
			szNewMsg = (LPSTR) mir_alloc(olen);
			memcpy(szNewMsg,szOldMsg,olen);
			ppre->flags |= PREF_UNICODE;
			pccsd->wParam |= PREF_UNICODE;
		}
	}
	ppre->szMessage = szNewMsg;
	return szNewMsg;
}


BOOL LoadKeyPGP(pUinKey ptr)
{
	int mode = db_get_b(ptr->hContact,MODULENAME,"pgp_mode",255);
	if (mode == 0) {
		DBVARIANT dbv;
		db_get(ptr->hContact,MODULENAME,"pgp",&dbv);
		BOOL r=(dbv.type == DBVT_BLOB);
		if (r) pgp_set_keyid(ptr->cntx,(PVOID)dbv.pbVal);
		db_free(&dbv);
		return r;
	}
	if (mode == 1) {
		LPSTR key = db_get_sa(ptr->hContact,MODULENAME,"pgp");
		if (key) {
			pgp_set_key(ptr->cntx,key);
			mir_free(key);
			return 1;
		}
	}
	return 0;
}

BOOL LoadKeyGPG(pUinKey ptr)
{
	LPSTR key = db_get_sa(ptr->hContact,MODULENAME,"gpg");
	if (key) {
		gpg_set_keyid(ptr->cntx,key);
		mir_free(key);
		return 2;
	}
	return 0;
}

// EOF