QByteArray SshAbstractCryptoFacility::generateHash(const SshKeyExchange &kex,
char c, quint32 length)
{
const QByteArray &k = kex.k();
const QByteArray &h = kex.h();
QByteArray data(k);
data.append(h).append(c).append(m_sessionId);
SecureVector<byte> key
= kex.hash()->process(convertByteArray(data), data.size());
while (key.size() < length) {
SecureVector<byte> tmpKey;
tmpKey.append(convertByteArray(k), k.size());
tmpKey.append(convertByteArray(h), h.size());
tmpKey.append(key);
key.append(kex.hash()->process(tmpKey));
}
return QByteArray(reinterpret_cast<const char *>(key.begin()), length);
}
/*************************************************
* Decode a BigInt *
*************************************************/
BigInt BigInt::decode(const byte buf[], u32bit length, Base base)
{
BigInt r;
if(base == Binary)
r.binary_decode(buf, length);
#ifndef BOTAN_MINIMAL_BIGINT
else if(base == Hexadecimal)
{
SecureVector<byte> hex;
for(u32bit j = 0; j != length; ++j)
if(Hex_Decoder::is_valid(buf[j]))
hex.append(buf[j]);
u32bit offset = (hex.size() % 2);
SecureVector<byte> binary(hex.size() / 2 + offset);
if(offset)
{
byte temp[2] = { '0', hex[0] };
binary[0] = Hex_Decoder::decode(temp);
}
for(u32bit j = offset; j != binary.size(); ++j)
binary[j] = Hex_Decoder::decode(hex+2*j-offset);
r.binary_decode(binary, binary.size());
}
#endif
else if(base == Decimal || base == Octal)
{
const u32bit RADIX = ((base == Decimal) ? 10 : 8);
for(u32bit j = 0; j != length; ++j)
{
byte x = Charset::char2digit(buf[j]);
if(x >= RADIX)
{
if(RADIX == 10)
throw Invalid_Argument("BigInt: Invalid decimal string");
else
throw Invalid_Argument("BigInt: Invalid octal string");
}
r *= RADIX;
r += x;
}
}
else
throw Invalid_Argument("Unknown BigInt decoding method");
return r;
}