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/*************************************************
* BigInt Header File *
* (C) 1999-2008 Jack Lloyd *
*************************************************/
#ifndef BOTAN_BIGINT_H__
#define BOTAN_BIGINT_H__
#include <botan/rng.h>
#include <botan/secmem.h>
#include <botan/mp_types.h>
#include <iosfwd>
namespace Botan {
/*************************************************
* BigInt *
*************************************************/
class BOTAN_DLL BigInt
{
public:
enum Base { Octal = 8, Decimal = 10, Hexadecimal = 16, Binary = 256 };
enum Sign { Negative = 0, Positive = 1 };
enum NumberType { Power2 };
struct DivideByZero : public Exception
{ DivideByZero() : Exception("BigInt divide by zero") {} };
BigInt& operator+=(const BigInt&);
BigInt& operator-=(const BigInt&);
BigInt& operator*=(const BigInt&);
BigInt& operator/=(const BigInt&);
BigInt& operator%=(const BigInt&);
word operator%=(word);
BigInt& operator<<=(u32bit);
BigInt& operator>>=(u32bit);
BigInt& operator++() { return (*this += 1); }
BigInt& operator--() { return (*this -= 1); }
BigInt operator++(int) { BigInt x = (*this); ++(*this); return x; }
BigInt operator--(int) { BigInt x = (*this); --(*this); return x; }
BigInt operator-() const;
bool operator !() const { return (!is_nonzero()); }
s32bit cmp(const BigInt&, bool = true) const;
bool is_even() const { return (get_bit(0) == 0); }
bool is_odd() const { return (get_bit(0) == 1); }
bool is_zero() const
{
for(u32bit i = 0; i != rep.sig_words(); ++i)
if(rep[i]) return false;
return true;
}
bool is_nonzero() const { return (!is_zero()); }
void set_bit(u32bit);
void clear_bit(u32bit);
void mask_bits(u32bit);
bool get_bit(u32bit) const;
u32bit get_substring(u32bit, u32bit) const;
byte byte_at(u32bit) const;
// same as operator[], remove this
word word_at(u32bit n) const
{ return ((n < size()) ? get_reg()[n] : 0); }
u32bit to_u32bit() const;
bool is_negative() const { return (sign() == Negative); }
bool is_positive() const { return (sign() == Positive); }
Sign sign() const { return (signedness); }
Sign reverse_sign() const;
void flip_sign();
void set_sign(Sign);
BigInt abs() const;
u32bit size() const { return get_reg().size(); }
u32bit sig_words() const { return rep.sig_words(); }
u32bit bytes() const;
u32bit bits() const;
const word* data() const { return get_reg().begin(); }
SecureVector<word>& get_reg() { return rep.get_reg(); }
const SecureVector<word>& get_reg() const { return rep.get_reg(); }
void grow_reg(u32bit);
void grow_to(u32bit);
word& operator[](u32bit i) { return rep[i]; }
word operator[](u32bit i) const { return rep[i]; }
void clear() { get_reg().clear(); }
void randomize(RandomNumberGenerator& rng, u32bit n);
void binary_encode(byte[]) const;
void binary_decode(const byte[], u32bit);
void binary_decode(const MemoryRegion<byte>&);
u32bit encoded_size(Base = Binary) const;
static SecureVector<byte> encode(const BigInt&, Base = Binary);
static void encode(byte[], const BigInt&, Base = Binary);
static BigInt decode(const byte[], u32bit, Base = Binary);
static BigInt decode(const MemoryRegion<byte>&, Base = Binary);
static SecureVector<byte> encode_1363(const BigInt&, u32bit);
void swap(BigInt&);
BigInt() { signedness = Positive; }
BigInt(u64bit);
BigInt(const BigInt&);
BigInt(const std::string&);
BigInt(const byte[], u32bit, Base = Binary);
BigInt(RandomNumberGenerator& rng, u32bit bits);
BigInt(Sign, u32bit);
BigInt(NumberType, u32bit);
private:
class Rep
{
private:
static const u32bit INVALID_SIG_WORD = 0xFFFFFFFF;
mutable u32bit sig;
SecureVector<word> reg;
public:
Rep() { sig = INVALID_SIG_WORD; }
void swap(Rep& other)
{
std::swap(reg, other.reg);
std::swap(sig, other.sig);
}
SecureVector<word>& get_reg()
{ sig = INVALID_SIG_WORD; return reg; }
word& operator[](u32bit n)
{
sig = INVALID_SIG_WORD;
if(n > reg.size())
reg.grow_to(n+1);
return reg[n];
}
word operator[](u32bit n) const
{
if(n > reg.size())
return 0;
return reg[n];
}
const SecureVector<word>& get_reg() const { return reg; }
/*************************************************
* Count the significant words, if cached value is
* not valid
*************************************************/
u32bit sig_words() const
{
if(sig == INVALID_SIG_WORD)
{
const word* x = reg.begin();
u32bit top_set = reg.size();
while(top_set && (x[top_set-1] == 0))
top_set--;
sig = top_set;
}
return sig;
}
};
Rep rep;
Sign signedness;
};
/*************************************************
* Arithmetic Operators *
*************************************************/
BigInt BOTAN_DLL operator+(const BigInt&, const BigInt&);
BigInt BOTAN_DLL operator-(const BigInt&, const BigInt&);
BigInt BOTAN_DLL operator*(const BigInt&, const BigInt&);
BigInt BOTAN_DLL operator/(const BigInt&, const BigInt&);
BigInt BOTAN_DLL operator%(const BigInt&, const BigInt&);
word BOTAN_DLL operator%(const BigInt&, word);
BigInt BOTAN_DLL operator<<(const BigInt&, u32bit);
BigInt BOTAN_DLL operator>>(const BigInt&, u32bit);
/*************************************************
* Comparison Operators *
*************************************************/
inline bool operator==(const BigInt& a, const BigInt& b)
{ return (a.cmp(b) == 0); }
inline bool operator!=(const BigInt& a, const BigInt& b)
{ return (a.cmp(b) != 0); }
inline bool operator<=(const BigInt& a, const BigInt& b)
{ return (a.cmp(b) <= 0); }
inline bool operator>=(const BigInt& a, const BigInt& b)
{ return (a.cmp(b) >= 0); }
inline bool operator<(const BigInt& a, const BigInt& b)
{ return (a.cmp(b) < 0); }
inline bool operator>(const BigInt& a, const BigInt& b)
{ return (a.cmp(b) > 0); }
/*************************************************
* I/O Operators *
*************************************************/
BOTAN_DLL std::ostream& operator<<(std::ostream&, const BigInt&);
BOTAN_DLL std::istream& operator>>(std::istream&, BigInt&);
}
namespace std {
inline void swap(Botan::BigInt& a, Botan::BigInt& b) { a.swap(b); }
}
#endif
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