C++ KviCString::setLen方法代码示例

	void decode(KviCString & szText, unsigned char ** buf, int *len)
	{
		// make sure its length is multiple of 12 (eventually pad with zeroes)
		if(szText.len() % 12)
		{
			int oldL = szText.len();
			szText.setLen(szText.len() + (12 - (szText.len() % 12)));
			char * padB = szText.ptr() + oldL;
			char * padE = szText.ptr() + szText.len();
			while(padB < padE)*padB++ = 0;
		}

		*len = (int)(szText.len() * 2) / 3;

		*buf = (unsigned char *)KviMemory::allocate(*len);
		unsigned char * p = (unsigned char *)szText.ptr();
		unsigned char * e = p + szText.len();
		int i;
		unsigned char * bufp = *buf;
		while(p < e)
		{
			quint32 * dw1 = (quint32 *)bufp;
			bufp += 4;
			quint32 * dw2 = (quint32 *)bufp;
			bufp += 4;
			*dw2 = 0;
			for(i=0;i < 6;i++)*dw2 |= (fake_base64dec(*p++)) << (i * 6);
			*dw1 = 0;
			for(i=0;i < 6;i++)*dw1 |= (fake_base64dec(*p++)) << (i * 6);
		}

		// FIXME: this is probably needed only on LittleEndian machines!
		byteswap_buffer(*buf,*len);
	}

bool KviMircryptionEngine::doEncryptCBC(KviCString & plain, KviCString & encoded)
{
	// make sure it is a multiple of 8 bytes (eventually pad with zeroes)
	if(plain.len() % 8)
	{
		int oldL = plain.len();
		plain.setLen(plain.len() + (8 - (plain.len() % 8)));
		char * padB = plain.ptr() + oldL;
		char * padE = plain.ptr() + plain.len();
		while(padB < padE)
			*padB++ = 0;
	}

	int ll = plain.len() + 8;
	unsigned char * in = (unsigned char *)KviMemory::allocate(ll);

	InitVectorEngine::fillRandomIV(in, 8);

	KviMemory::copy(in + 8, plain.ptr(), plain.len());

	// encrypt
	unsigned char * out = (unsigned char *)KviMemory::allocate(ll);
	BlowFish bf((unsigned char *)m_szEncryptKey.ptr(), m_szEncryptKey.len());
	bf.ResetChain();
	bf.Encrypt(in, out, ll, BlowFish::CBC);
	KviMemory::free(in);

	encoded.bufferToBase64((const char *)out, ll);
	KviMemory::free(out);

	encoded.prepend('*'); // prepend the signature

	return true;
}

bool KviFile::load(KviCString & szData)
{
	kvi_u32_t iLen;
	if(!load(iLen))
		return false;
	szData.setLen(iLen);
	return (read((char *)(szData.ptr()), iLen) == iLen);
}

bool KviMircryptionEngine::doDecryptECB(KviCString & encoded, KviCString & plain)
{
	unsigned char * buf = nullptr;
	int len;
	UglyBase64::decode(encoded, &buf, &len);

	plain.setLen(len);
	BlowFish bf((unsigned char *)m_szDecryptKey.ptr(), m_szDecryptKey.len());
	bf.ResetChain();
	bf.Decrypt(buf, (unsigned char *)plain.ptr(), len, BlowFish::ECB);

	KviMemory::free(buf);

	return true;
}

bool KviMircryptionEngine::doEncryptECB(KviCString & plain, KviCString & encoded)
{
	// make sure it is a multiple of 8 bytes (eventually pad with zeroes)
	if(plain.len() % 8)
	{
		int oldL = plain.len();
		plain.setLen(plain.len() + (8 - (plain.len() % 8)));
		char * padB = plain.ptr() + oldL;
		char * padE = plain.ptr() + plain.len();
		while(padB < padE)
			*padB++ = 0;
	}

	unsigned char * out = (unsigned char *)KviMemory::allocate(plain.len()); // we use this to avoid endiannes problems

	BlowFish bf((unsigned char *)m_szEncryptKey.ptr(), m_szEncryptKey.len());
	bf.ResetChain();
	bf.Encrypt((unsigned char *)plain.ptr(), out, plain.len(), BlowFish::ECB);

	UglyBase64::encode(out, plain.len(), encoded);
	KviMemory::free(out);
	return true;
}

bool KviMircryptionEngine::doDecryptCBC(KviCString & encoded, KviCString & plain)
{
	if(*(encoded.ptr()) != '*')
	{
		qDebug("WARNING: specified a CBC key but the incoming message doesn't seem to be a CBC one");
		return doDecryptECB(encoded, plain);
	}
	encoded.cutLeft(1);

	char * tmpBuf;
	int len = encoded.base64ToBuffer(&tmpBuf, false);
	if(len < 0)
	{
		setLastError(__tr2qs("The message is not a base64 string: this is not my stuff"));
		return false;
	}
	if((len < 8) || (len % 8))
	{
		setLastError(__tr2qs("The message doesn't seem to be encoded with CBC Mircryption"));
		if(len > 0)
			KviCString::freeBuffer(tmpBuf);
		return false;
	}

	plain.setLen(len);
	BlowFish bf((unsigned char *)m_szDecryptKey.ptr(), m_szDecryptKey.len());
	bf.ResetChain();
	bf.Decrypt((unsigned char *)tmpBuf, (unsigned char *)plain.ptr(), len, BlowFish::CBC);

	// kill the first 8 bytes (random IV)
	plain.cutLeft(8);

	KviCString::freeBuffer(tmpBuf);

	return true;
}