Function evlRsaSign

src/jrd/SysFunction.cpp:3922–3977

dsc* evlRsaSign(thread_db* tdbb, const SysFunction* function, const NestValueArray& args, impure_value* impure)
{
	tomcryptInitializer();

	fb_assert(args.getCount() == RSA_SIGN_ARG_MAX || args.getCount() == RSA_SIGN_ARG_MAX - 1);

	Request* request = tdbb->getRequest();

	// parse args and check correctness
	const dsc* dscs[RSA_SIGN_ARG_MAX];
	for (unsigned i = 0; i < args.getCount(); ++i)
		dscs[i] = EVL_expr(tdbb, request, args[i]);

	SSHORT pkcs15 = args.getCount() < RSA_SIGN_ARG_MAX ? 0 : *(SSHORT*)(dscs[RSA_SIGN_ARG_PKCS_1_5]->dsc_address);

	MetaName hashName;
	if (dscs[RSA_SIGN_ARG_HASH])
		MOV_get_metaname(tdbb, dscs[RSA_SIGN_ARG_HASH], hashName);
	if (!hashName.hasData())
		hashName = "SHA256";
	string aName(hashName);
	aName.lower();
	int hash = find_hash(aName.c_str());
	if (hash < 0)
		status_exception::raise(Arg::Gds(isc_tom_hash_bad) << hashName);

	DscValue data(tdbb, dscs[RSA_SIGN_ARG_VALUE]);
	if (!data.getBytes())
		return nullptr;

	DscValue key(tdbb, dscs[RSA_SIGN_ARG_KEY], "private key");
	if (!key.getBytes())
		return nullptr;
	rsa_key rsaKey;
	tomCheck(rsa_import(key.getBytes(), key.getLength(), &rsaKey), Arg::Gds(isc_tom_rsa_import));

	SLONG saltLength = 8;
	if (dscHasData(dscs[RSA_SIGN_ARG_SALTLEN]))
	{
		saltLength = MOV_get_long(tdbb, dscs[RSA_SIGN_ARG_SALTLEN], 0);
		if (saltLength < 0 || saltLength > getMaxSaltlen(hash, &rsaKey))
			status_exception::raise(Arg::Gds(isc_arith_except) << Arg::Gds(isc_numeric_out_of_range));
	}

	unsigned long signLen = 1024;
	UCharBuffer sign;
	int cryptRc = rsa_sign_hash_ex(data.getBytes(), data.getLength(), sign.getBuffer(signLen), &signLen,
		pkcs15 ? LTC_PKCS_1_V1_5 : LTC_PKCS_1_PSS, prng().getState(), prng().getIndex(), hash, saltLength, &rsaKey);
	rsa_free(&rsaKey);
	tomCheck(cryptRc, Arg::Gds(isc_tom_rsa_sign));

	dsc result;
	result.makeText(signLen, ttype_binary, sign.begin());
	EVL_make_value(tdbb, &result, impure);
	return &impure->vlu_desc;
}