integer.h File Reference

Multiple precision integer with arithmetic operations. More...

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Classes
struct	InitializeInteger
	Performs static initialization of the Integer class. More...
class	Integer
	Multiple precision integer with arithmetic operations. More...
class	Integer::DivideByZero
	Exception thrown when division by 0 is encountered. More...
class	Integer::RandomNumberNotFound
	Exception thrown when a random number cannot be found that satisfies the condition. More...
class	Integer::OpenPGPDecodeErr
	Exception thrown when an error is encountered decoding an OpenPGP integer. More...

Typedefs
typedef SecBlock< word, AllocatorWithCleanup< word, true > >	IntegerSecBlock

Functions
bool	operator== (const ::Integer &a, const ::Integer &b)
	Comparison.
bool	operator!= (const ::Integer &a, const ::Integer &b)
	Comparison.
bool	operator> (const ::Integer &a, const ::Integer &b)
	Comparison.
bool	operator>= (const ::Integer &a, const ::Integer &b)
	Comparison.
bool	operator< (const ::Integer &a, const ::Integer &b)
	Comparison.
bool	operator<= (const ::Integer &a, const ::Integer &b)
	Comparison.
inline ::Integer	operator+ (const ::Integer &a, const ::Integer &b)
	Addition.
inline ::Integer	operator- (const ::Integer &a, const ::Integer &b)
	Subtraction.
inline ::Integer	operator* (const ::Integer &a, const ::Integer &b)
	Multiplication. More...
inline ::Integer	operator/ (const ::Integer &a, const ::Integer &b)
	Division.
inline ::Integer	operator% (const ::Integer &a, const ::Integer &b)
	Remainder. More...
inline ::Integer	operator/ (const ::Integer &a, ::word b)
	Division.
inline ::word	operator% (const ::Integer &a, ::word b)
	Remainder. More...
inline ::Integer	operator& (const ::Integer &a, const ::Integer &b)
	Bitwise AND. More...
inline ::Integer	operator| (const ::Integer &a, const ::Integer &b)
	Bitwise OR. More...
inline ::Integer	operator^ (const ::Integer &a, const ::Integer &b)
	Bitwise XOR. More...
void	swap (::Integer &a, ::Integer &b)

Detailed Description

Multiple precision integer with arithmetic operations.

The Integer class can represent positive and negative integers with absolute value less than (256**sizeof(word))^{(256**sizeof(int))}.

Internally, the library uses a sign magnitude representation, and the class has two data members. The first is a IntegerSecBlock (a SecBlock<word>) and it is used to hold the representation. The second is a Sign (an enumeration), and it is used to track the sign of the Integer.

For details on how the Integer class initializes its function pointers using InitializeInteger and how it creates Integer::Zero(), Integer::One(), and Integer::Two(), then see the comments at the top of integer.cpp.

Since

Crypto++ 1.0

Definition in file integer.h.

Function Documentation

operator*()

inline ::Integer operator*	(	const ::Integer &	a,
		const ::Integer &	b
	)

Multiplication.

See also

a_times_b_mod_c() and a_exp_b_mod_c()

Definition at line 775 of file integer.h.

operator%() [1/2]

inline ::Integer operator%	(	const ::Integer &	a,
		const ::Integer &	b
	)

Remainder.

See also

a_times_b_mod_c() and a_exp_b_mod_c()

Definition at line 780 of file integer.h.

operator%() [2/2]

inline ::word operator%	(	const ::Integer &	a,
		::word	b
	)

Remainder.

See also

a_times_b_mod_c() and a_exp_b_mod_c()

Definition at line 785 of file integer.h.

operator&()

inline ::Integer operator&	(	const ::Integer &	a,
		const ::Integer &	b
	)

Bitwise AND.

Parameters

a	the first Integer
b	the second Integer

Returns

the result of a & b

operator&() performs a bitwise AND on the operands. Missing bits are truncated at the most significant bit positions, so the result is as small as the smaller of the operands.

Internally, Crypto++ uses a sign-magnitude representation. The library does not attempt to interpret bits, and the result is always POSITIVE. If needed, the integer should be converted to a 2's compliment representation before performing the operation.

Since

Crypto++ 6.0

Definition at line 799 of file integer.h.

operator|()

inline ::Integer operator|	(	const ::Integer &	a,
		const ::Integer &	b
	)

Bitwise OR.

Parameters

a	the first Integer
b	the second Integer

Returns

the result of a | b

operator|() performs a bitwise OR on the operands. Missing bits are shifted in at the most significant bit positions, so the result is as large as the larger of the operands.

Internally, Crypto++ uses a sign-magnitude representation. The library does not attempt to interpret bits, and the result is always POSITIVE. If needed, the integer should be converted to a 2's compliment representation before performing the operation.

Since

Crypto++ 6.0

Definition at line 813 of file integer.h.

operator^()

inline ::Integer operator^	(	const ::Integer &	a,
		const ::Integer &	b
	)

Bitwise XOR.

Parameters

a	the first Integer
b	the second Integer

Returns

the result of a ^ b

operator^() performs a bitwise XOR on the operands. Missing bits are shifted in at the most significant bit positions, so the result is as large as the larger of the operands.

Internally, Crypto++ uses a sign-magnitude representation. The library does not attempt to interpret bits, and the result is always POSITIVE. If needed, the integer should be converted to a 2's compliment representation before performing the operation.

Since

Crypto++ 6.0

Definition at line 827 of file integer.h.