Big number operations. More...

Typedefs
typedef struct BigNum	BigNum
	Internal representation of large numbers.

Functions
EpidStatus	NewBigNum (size_t data_size_bytes, BigNum **bignum)
	Constructs a new BigNum. More...

void	DeleteBigNum (BigNum **bignum)
	Deletes a previously allocated BigNum. More...

EpidStatus	ReadBigNum (void const bn_str, size_t strlen, BigNum bn)
	Deserializes a BigNum from a string. More...

EpidStatus	WriteBigNum (BigNum const bn, size_t strlen, void bn_str)
	Serializes a BigNum to a string. More...

EpidStatus	BigNumAdd (BigNum const a, BigNum const b, BigNum *r)
	Adds two BigNum values. More...

EpidStatus	BigNumSub (BigNum const a, BigNum const b, BigNum *r)
	Subtracts two BigNum values. More...

EpidStatus	BigNumMul (BigNum const a, BigNum const b, BigNum *r)
	Multiplies two BigNum values. More...

EpidStatus	BigNumDiv (BigNum const a, BigNum const b, BigNum q, BigNum r)
	Divides two BigNum values. More...

EpidStatus	BigNumMod (BigNum const a, BigNum const b, BigNum *r)
	Computes modular reduction for BigNum value by specified modulus. More...

EpidStatus	BigNumIsEven (BigNum const a, bool is_even)
	Checks if a BigNum is even. More...

EpidStatus	BigNumIsZero (BigNum const a, bool is_zero)
	Checks if a BigNum is zero. More...

EpidStatus	BigNumPow2N (unsigned int n, BigNum *r)
	Raises 2 to the given power. More...

Detailed Description

Big number operations.

This module provides an API for working with large numbers. BigNums represent non-negative integers.

Each BigNum variable represents a number of a byte-size set when the variable was created. BigNum variables cannot be re-sized after they are created.

Function Documentation

EpidStatus BigNumAdd	(	BigNum const *	a,
		BigNum const *	b,
		BigNum *	r
	)

Adds two BigNum values.

Parameters

[in]	a	The first operand to be added.
[in]	b	The second operand to be added.
[out]	r	The result of adding a and b.

Returns: EpidStatus

EpidStatus BigNumDiv	(	BigNum const *	a,
		BigNum const *	b,
		BigNum *	q,
		BigNum *	r
	)

Divides two BigNum values.

Note: Only needed for Intel(R) EPID 1.1 verification.

Parameters

[in]	a	Dividend parameter.
[in]	b	Divisor parameter.
[out]	q	Quotient of result.
[out]	r	Remainder of result.

Returns: EpidStatus

EpidStatus BigNumIsEven	(	BigNum const *	a,
		bool *	is_even
	)

Checks if a BigNum is even.

Parameters

[in]	a	The BigNum to check.
[out]	is_even	The result of the check.

Returns: EpidStatus

EpidStatus BigNumIsZero	(	BigNum const *	a,
		bool *	is_zero
	)

Checks if a BigNum is zero.

Parameters

[in]	a	The BigNum to check.
[out]	is_zero	The result of the check.

Returns: EpidStatus

EpidStatus BigNumMod	(	BigNum const *	a,
		BigNum const *	b,
		BigNum *	r
	)

Computes modular reduction for BigNum value by specified modulus.

Parameters

[in]	a	The BigNum value.
[in]	b	The modulus.
[out]	r	Modular reduction result.

Returns: EpidStatus

EpidStatus BigNumMul	(	BigNum const *	a,
		BigNum const *	b,
		BigNum *	r
	)

Multiplies two BigNum values.

Parameters

[in]	a	The first operand to be multiplied.
[in]	b	The second operand to be multiplied.
[out]	r	The result of multiplying a and b.

Returns: EpidStatus

EpidStatus BigNumPow2N	(	unsigned int	n,
		BigNum *	r
	)

Raises 2 to the given power.

Parameters

[in]	n	The power.
[out]	r	The result of 2^n.

Returns: EpidStatus

EpidStatus BigNumSub	(	BigNum const *	a,
		BigNum const *	b,
		BigNum *	r
	)

Subtracts two BigNum values.

Parameters

[in]	a	The first operand to use in subtraction.
[in]	b	The second operand to use in subtraction.
[out]	r	The result of subtracting a and b.

Returns: EpidStatus

void DeleteBigNum ( BigNum ** bignum )

Deletes a previously allocated BigNum.

Frees memory pointed to by bignum. Nulls the pointer.

Parameters

[in] bignum The BigNum. Can be NULL.

See also: NewBigNum

EpidStatus NewBigNum	(	size_t	data_size_bytes,
		BigNum **	bignum
	)

Constructs a new BigNum.

Allocates memory and creates a new BigNum.

Use DeleteBigNum() to free memory.

Parameters

[in]	data_size_bytes	The size in bytes of the new number.
[out]	bignum	The BigNum.

Returns: EpidStatus

See also: DeleteBigNum

EpidStatus ReadBigNum	(	void const *	bn_str,
		size_t	strlen,
		BigNum *	bn
	)

Deserializes a BigNum from a string.

Parameters

[in]	bn_str	The serialized value.
[in]	strlen	The size of bn_str in bytes.
[out]	bn	The target BigNum.

Returns: EpidStatus

EpidStatus WriteBigNum	(	BigNum const *	bn,
		size_t	strlen,
		void *	bn_str
	)

Serializes a BigNum to a string.

Parameters

[in]	bn	The BigNum to be serialized.
[in]	strlen	The size of bn_str in bytes.
[out]	bn_str	The target string.

Returns: EpidStatus

Typedefs

Functions

Detailed Description

Function Documentation