#include "utils.h"

boost::posix_time::ptime ptEpoch()
{
	return boost::posix_time::ptime(boost::gregorian::date(2000, boost::gregorian::Jan, 1));
}

int iToSeconds(boost::posix_time::ptime ptWhen)
{
	return ptWhen.is_not_a_date_time()
		? -1
		: (ptWhen-ptEpoch()).total_seconds();
}

boost::posix_time::ptime ptFromSeconds(int iSeconds)
{
	return iSeconds < 0
		? boost::posix_time::ptime(boost::posix_time::not_a_date_time)
		: ptEpoch() + boost::posix_time::seconds(iSeconds);
}

char charHex(int iDigit)
{
	return iDigit < 10 ? '0' + iDigit : 'A' - 10 + iDigit;
}

int charUnHex(char cDigit)
{
	return cDigit >= '0' && cDigit <= '9'
		? cDigit - '0'
		: cDigit >= 'A' && cDigit <= 'F'
			? cDigit - 'A' + 10
			: cDigit >= 'a' && cDigit <= 'f'
				? cDigit - 'a' + 10
				: -1;
}

void strUnHex(std::string& strDst, const std::string& strSrc)
{
	int	iBytes	= strSrc.size()/2;

	strDst.resize(iBytes);

	for (int i=0; i != iBytes; i++)
		strDst[i]	= (charUnHex(strSrc[i*2]) << 4) | charUnHex(strSrc[i*2+1]);
}

void DH_der_gen(std::string& strDer, int iKeyLength)
{
	DH*	dh	= 0;
	int	iCodes;

	do {
		dh	= DH_generate_parameters(iKeyLength, DH_GENERATOR_5, NULL, NULL);
		iCodes	= 0;
		DH_check(dh, &iCodes);
	} while (iCodes & (DH_CHECK_P_NOT_PRIME|DH_CHECK_P_NOT_SAFE_PRIME|DH_UNABLE_TO_CHECK_GENERATOR|DH_NOT_SUITABLE_GENERATOR));

	strDer.resize(i2d_DHparams(dh, NULL));

	unsigned char* next	= reinterpret_cast<unsigned char *>(&strDer[0]);

	(void) i2d_DHparams(dh, &next);
}

void DH_der_gen_hex(std::string& strDer, int iKeyLength)
{
	std::string	strBuf;

	DH_der_gen(strBuf, iKeyLength);

	strHex(strDer, strBuf);
}

DH* DH_der_load(const std::string& strDer)
{
	const unsigned char *pbuf	= reinterpret_cast<const unsigned char *>(&strDer[0]);

	return d2i_DHparams(NULL, &pbuf, strDer.size());
}

DH* DH_der_load_hex(const std::string& strDer)
{
	std::string	strBuf;

	strUnHex(strBuf, strDer);

	return DH_der_load(strBuf);
}

// vim:ts=4