Multi-precision integer library. More...

#include <stdio.h>
#include <string.h>
#include "config.h"
#include <inttypes.h>

Include dependency graph for bignum.h:

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Data Structures
struct	mpi
	MPI structure. More...

Macros
#define	POLARSSL_ERR_MPI_FILE_IO_ERROR -0x0002
	An error occurred while reading from or writing to a file.

#define	POLARSSL_ERR_MPI_BAD_INPUT_DATA -0x0004
	Bad input parameters to function.

#define	POLARSSL_ERR_MPI_INVALID_CHARACTER -0x0006
	There is an invalid character in the digit string.

#define	POLARSSL_ERR_MPI_BUFFER_TOO_SMALL -0x0008
	The buffer is too small to write to.

#define	POLARSSL_ERR_MPI_NEGATIVE_VALUE -0x000A
	The input arguments are negative or result in illegal output.

#define	POLARSSL_ERR_MPI_DIVISION_BY_ZERO -0x000C
	The input argument for division is zero, which is not allowed.

#define	POLARSSL_ERR_MPI_NOT_ACCEPTABLE -0x000E
	The input arguments are not acceptable.

#define	POLARSSL_ERR_MPI_MALLOC_FAILED -0x0010
	Memory allocation failed.

#define	MPI_CHK(f) do { if( ( ret = f ) != 0 ) goto cleanup; } while( 0 )

#define	POLARSSL_MPI_MAX_LIMBS 10000

#define	POLARSSL_MPI_WINDOW_SIZE 6
	Maximum windows size used.

#define	POLARSSL_MPI_MAX_SIZE 1024
	Maximum number of bytes for usable MPIs.

#define	POLARSSL_MPI_MAX_BITS ( 8 * POLARSSL_MPI_MAX_SIZE )
	Maximum number of bits for usable MPIs.

#define	POLARSSL_MPI_MAX_BITS_SCALE100 ( 100 * POLARSSL_MPI_MAX_BITS )

#define	LN_2_DIV_LN_10_SCALE100 332

#define	POLARSSL_MPI_RW_BUFFER_SIZE ( ((POLARSSL_MPI_MAX_BITS_SCALE100 + LN_2_DIV_LN_10_SCALE100 - 1) / LN_2_DIV_LN_10_SCALE100) + 10 + 6 )

#define	POLARSSL_HAVE_INT32

#define	POLARSSL_HAVE_UDBL

Typedefs
typedef int32_t	t_sint

typedef uint32_t	t_uint

typedef unsigned long long	t_udbl

Functions
void	mpi_init (mpi *X)
	Initialize one MPI.

void	mpi_free (mpi *X)
	Unallocate one MPI.

int	mpi_grow (mpi *X, size_t nblimbs)
	Enlarge to the specified number of limbs.

int	mpi_shrink (mpi *X, size_t nblimbs)
	Resize down, keeping at least the specified number of limbs.

int	mpi_copy (mpi X, const mpi Y)
	Copy the contents of Y into X.

void	mpi_swap (mpi X, mpi Y)
	Swap the contents of X and Y.

int	mpi_safe_cond_assign (mpi X, const mpi Y, unsigned char assign)
	Safe conditional assignement X = Y if assign is 1.

int	mpi_safe_cond_swap (mpi X, mpi Y, unsigned char assign)
	Safe conditional swap X <-> Y if swap is 1.

int	mpi_lset (mpi *X, t_sint z)
	Set value from integer.

int	mpi_get_bit (const mpi *X, size_t pos)
	Get a specific bit from X.

int	mpi_set_bit (mpi *X, size_t pos, unsigned char val)
	Set a bit of X to a specific value of 0 or 1.

size_t	mpi_lsb (const mpi *X)
	Return the number of zero-bits before the least significant '1' bit.

size_t	mpi_msb (const mpi *X)
	Return the number of bits up to and including the most significant '1' bit'.

size_t	mpi_size (const mpi *X)
	Return the total size in bytes.

int	mpi_read_string (mpi X, int radix, const char s)
	Import from an ASCII string.

int	mpi_write_string (const mpi X, int radix, char s, size_t *slen)
	Export into an ASCII string.

int	mpi_read_file (mpi X, int radix, FILE fin)
	Read X from an opened file.

int	mpi_write_file (const char p, const mpi X, int radix, FILE *fout)
	Write X into an opened file, or stdout if fout is NULL.

int	mpi_read_binary (mpi X, const unsigned char buf, size_t buflen)
	Import X from unsigned binary data, big endian.

int	mpi_write_binary (const mpi X, unsigned char buf, size_t buflen)
	Export X into unsigned binary data, big endian.

int	mpi_shift_l (mpi *X, size_t count)
	Left-shift: X <<= count.

int	mpi_shift_r (mpi *X, size_t count)
	Right-shift: X >>= count.

int	mpi_cmp_abs (const mpi X, const mpi Y)
	Compare unsigned values.

int	mpi_cmp_mpi (const mpi X, const mpi Y)
	Compare signed values.

int	mpi_cmp_int (const mpi *X, t_sint z)
	Compare signed values.

int	mpi_add_abs (mpi X, const mpi A, const mpi *B)
	Unsigned addition: X = \|A\| + \|B\|.

int	mpi_sub_abs (mpi X, const mpi A, const mpi *B)
	Unsigned subtraction: X = \|A\| - \|B\|.

int	mpi_add_mpi (mpi X, const mpi A, const mpi *B)
	Signed addition: X = A + B.

int	mpi_sub_mpi (mpi X, const mpi A, const mpi *B)
	Signed subtraction: X = A - B.

int	mpi_add_int (mpi X, const mpi A, t_sint b)
	Signed addition: X = A + b.

int	mpi_sub_int (mpi X, const mpi A, t_sint b)
	Signed subtraction: X = A - b.

int	mpi_mul_mpi (mpi X, const mpi A, const mpi *B)
	Baseline multiplication: X = A * B.

int	mpi_mul_int (mpi X, const mpi A, t_sint b)
	Baseline multiplication: X = A * b Note: despite the functon signature, b is treated as a t_uint.

int	mpi_div_mpi (mpi Q, mpi R, const mpi A, const mpi B)
	Division by mpi: A = Q * B + R.

int	mpi_div_int (mpi Q, mpi R, const mpi *A, t_sint b)
	Division by int: A = Q * b + R.

int	mpi_mod_mpi (mpi R, const mpi A, const mpi *B)
	Modulo: R = A mod B.

int	mpi_mod_int (t_uint r, const mpi A, t_sint b)
	Modulo: r = A mod b.

int	mpi_exp_mod (mpi X, const mpi A, const mpi E, const mpi N, mpi *_RR)
	Sliding-window exponentiation: X = A^E mod N.

int	mpi_fill_random (mpi X, size_t size, int(f_rng)(void , unsigned char , size_t), void *p_rng)
	Fill an MPI X with size bytes of random.

int	mpi_gcd (mpi G, const mpi A, const mpi *B)
	Greatest common divisor: G = gcd(A, B)

int	mpi_inv_mod (mpi X, const mpi A, const mpi *N)
	Modular inverse: X = A^-1 mod N.

int	mpi_is_prime (mpi X, int(f_rng)(void , unsigned char , size_t), void *p_rng)
	Miller-Rabin primality test.

int	mpi_gen_prime (mpi X, size_t nbits, int dh_flag, int(f_rng)(void , unsigned char , size_t), void *p_rng)
	Prime number generation.

int	mpi_self_test (int verbose)
	Checkup routine.

Detailed Description

Multi-precision integer library.

This file is part of PolarSSL (http://www.polarssl.org) Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Definition in file bignum.h.

Macro Definition Documentation

◆ LN_2_DIV_LN_10_SCALE100

#define LN_2_DIV_LN_10_SCALE100 332

Definition at line 117 of file bignum.h.

◆ MPI_CHK

#define MPI_CHK ( f ) do { if( ( ret = f ) != 0 ) goto cleanup; } while( 0 )

Definition at line 65 of file bignum.h.

◆ POLARSSL_ERR_MPI_BAD_INPUT_DATA

#define POLARSSL_ERR_MPI_BAD_INPUT_DATA -0x0004

Bad input parameters to function.

Definition at line 57 of file bignum.h.

◆ POLARSSL_ERR_MPI_BUFFER_TOO_SMALL

#define POLARSSL_ERR_MPI_BUFFER_TOO_SMALL -0x0008

The buffer is too small to write to.

Definition at line 59 of file bignum.h.

◆ POLARSSL_ERR_MPI_DIVISION_BY_ZERO

#define POLARSSL_ERR_MPI_DIVISION_BY_ZERO -0x000C

The input argument for division is zero, which is not allowed.

Definition at line 61 of file bignum.h.

◆ POLARSSL_ERR_MPI_FILE_IO_ERROR

#define POLARSSL_ERR_MPI_FILE_IO_ERROR -0x0002

An error occurred while reading from or writing to a file.

Definition at line 56 of file bignum.h.

◆ POLARSSL_ERR_MPI_INVALID_CHARACTER

#define POLARSSL_ERR_MPI_INVALID_CHARACTER -0x0006

There is an invalid character in the digit string.

Definition at line 58 of file bignum.h.

◆ POLARSSL_ERR_MPI_MALLOC_FAILED

#define POLARSSL_ERR_MPI_MALLOC_FAILED -0x0010

Memory allocation failed.

Definition at line 63 of file bignum.h.

◆ POLARSSL_ERR_MPI_NEGATIVE_VALUE

#define POLARSSL_ERR_MPI_NEGATIVE_VALUE -0x000A

The input arguments are negative or result in illegal output.

Definition at line 60 of file bignum.h.

◆ POLARSSL_ERR_MPI_NOT_ACCEPTABLE

#define POLARSSL_ERR_MPI_NOT_ACCEPTABLE -0x000E

The input arguments are not acceptable.

Definition at line 62 of file bignum.h.

◆ POLARSSL_HAVE_INT32

#define POLARSSL_HAVE_INT32

Definition at line 158 of file bignum.h.

◆ POLARSSL_HAVE_UDBL

#define POLARSSL_HAVE_UDBL

Definition at line 167 of file bignum.h.

◆ POLARSSL_MPI_MAX_BITS

#define POLARSSL_MPI_MAX_BITS ( 8 * POLARSSL_MPI_MAX_SIZE )

Maximum number of bits for usable MPIs.

Definition at line 96 of file bignum.h.

◆ POLARSSL_MPI_MAX_BITS_SCALE100

#define POLARSSL_MPI_MAX_BITS_SCALE100 ( 100 * POLARSSL_MPI_MAX_BITS )

Definition at line 116 of file bignum.h.

◆ POLARSSL_MPI_MAX_LIMBS

#define POLARSSL_MPI_MAX_LIMBS 10000

Definition at line 70 of file bignum.h.

◆ POLARSSL_MPI_MAX_SIZE

#define POLARSSL_MPI_MAX_SIZE 1024

Maximum number of bytes for usable MPIs.

Definition at line 93 of file bignum.h.

◆ POLARSSL_MPI_RW_BUFFER_SIZE

#define POLARSSL_MPI_RW_BUFFER_SIZE ( ((POLARSSL_MPI_MAX_BITS_SCALE100 + LN_2_DIV_LN_10_SCALE100 - 1) / LN_2_DIV_LN_10_SCALE100) + 10 + 6 )

Definition at line 118 of file bignum.h.

◆ POLARSSL_MPI_WINDOW_SIZE

#define POLARSSL_MPI_WINDOW_SIZE 6

Maximum windows size used.

Definition at line 82 of file bignum.h.

Typedef Documentation

◆ t_sint

typedef int32_t t_sint

Definition at line 159 of file bignum.h.

◆ t_udbl

typedef unsigned long long t_udbl

Definition at line 166 of file bignum.h.

◆ t_uint

typedef uint32_t t_uint

Definition at line 160 of file bignum.h.

Function Documentation

◆ mpi_add_abs()

int mpi_add_abs	(	mpi *	X,
		const mpi *	A,
		const mpi *	B
	)

Unsigned addition: X = |A| + |B|.

Parameters

X	Destination MPI
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_add_int()

int mpi_add_int	(	mpi *	X,
		const mpi *	A,
		t_sint	b
	)

Signed addition: X = A + b.

Parameters

X	Destination MPI
A	Left-hand MPI
b	The integer value to add

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_add_mpi()

int mpi_add_mpi	(	mpi *	X,
		const mpi *	A,
		const mpi *	B
	)

Signed addition: X = A + B.

Parameters

X	Destination MPI
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_cmp_abs()

int mpi_cmp_abs	(	const mpi *	X,
		const mpi *	Y
	)

Compare unsigned values.

Parameters

X	Left-hand MPI
Y	Right-hand MPI

Returns: 1 if |X| is greater than |Y|, -1 if |X| is lesser than |Y| or 0 if |X| is equal to |Y|

◆ mpi_cmp_int()

int mpi_cmp_int	(	const mpi *	X,
		t_sint	z
	)

Compare signed values.

Parameters

X	Left-hand MPI
z	The integer value to compare to

Returns: 1 if X is greater than z, -1 if X is lesser than z or 0 if X is equal to z

◆ mpi_cmp_mpi()

int mpi_cmp_mpi	(	const mpi *	X,
		const mpi *	Y
	)

Compare signed values.

Parameters

X	Left-hand MPI
Y	Right-hand MPI

Returns: 1 if X is greater than Y, -1 if X is lesser than Y or 0 if X is equal to Y

◆ mpi_copy()

int mpi_copy	(	mpi *	X,
		const mpi *	Y
	)

Copy the contents of Y into X.

Parameters

X	Destination MPI
Y	Source MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_div_int()

int mpi_div_int	(	mpi *	Q,
		mpi *	R,
		const mpi *	A,
		t_sint	b
	)

Division by int: A = Q * b + R.

Parameters

Q	Destination MPI for the quotient
R	Destination MPI for the rest value
A	Left-hand MPI
b	Integer to divide by

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_DIVISION_BY_ZERO if b == 0

Note: Either Q or R can be NULL.

◆ mpi_div_mpi()

int mpi_div_mpi	(	mpi *	Q,
		mpi *	R,
		const mpi *	A,
		const mpi *	B
	)

Division by mpi: A = Q * B + R.

Parameters

Q	Destination MPI for the quotient
R	Destination MPI for the rest value
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_DIVISION_BY_ZERO if B == 0

Note: Either Q or R can be NULL.

◆ mpi_exp_mod()

int mpi_exp_mod	(	mpi *	X,
		const mpi *	A,
		const mpi *	E,
		const mpi *	N,
		mpi *	_RR
	)

Sliding-window exponentiation: X = A^E mod N.

Parameters

X	Destination MPI
A	Left-hand MPI
E	Exponent MPI
N	Modular MPI
_RR	Speed-up MPI used for recalculations

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_BAD_INPUT_DATA if N is negative or even or if E is negative

Note: _RR is used to avoid re-computing R*R mod N across multiple calls, which speeds up things a bit. It can be set to NULL if the extra performance is unneeded.

◆ mpi_fill_random()

int mpi_fill_random	(	mpi *	X,
		size_t	size,
		int()(void , unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Fill an MPI X with size bytes of random.

Parameters

X	Destination MPI
size	Size in bytes
f_rng	RNG function
p_rng	RNG parameter

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_free()

void mpi_free ( mpi * X )

Unallocate one MPI.

Parameters

X	One MPI to unallocate.

◆ mpi_gcd()

int mpi_gcd	(	mpi *	G,
		const mpi *	A,
		const mpi *	B
	)

Greatest common divisor: G = gcd(A, B)

Parameters

G	Destination MPI
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_gen_prime()

int mpi_gen_prime	(	mpi *	X,
		size_t	nbits,
		int	dh_flag,
		int()(void , unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Prime number generation.

Parameters

X	Destination MPI
nbits	Required size of X in bits ( 3 <= nbits <= POLARSSL_MPI_MAX_BITS )
dh_flag	If 1, then (X-1)/2 will be prime too
f_rng	RNG function
p_rng	RNG parameter

Returns: 0 if successful (probably prime), POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_BAD_INPUT_DATA if nbits is < 3

◆ mpi_get_bit()

int mpi_get_bit	(	const mpi *	X,
		size_t	pos
	)

Get a specific bit from X.

Parameters

X	MPI to use
pos	Zero-based index of the bit in X

Returns: Either a 0 or a 1

◆ mpi_grow()

int mpi_grow	(	mpi *	X,
		size_t	nblimbs
	)

Enlarge to the specified number of limbs.

Parameters

X	MPI to grow
nblimbs	The target number of limbs

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_init()

void mpi_init ( mpi * X )

Initialize one MPI.

Parameters

X	One MPI to initialize.

◆ mpi_inv_mod()

int mpi_inv_mod	(	mpi *	X,
		const mpi *	A,
		const mpi *	N
	)

Modular inverse: X = A^-1 mod N.

Parameters

X	Destination MPI
A	Left-hand MPI
N	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_BAD_INPUT_DATA if N is negative or nil POLARSSL_ERR_MPI_NOT_ACCEPTABLE if A has no inverse mod N

◆ mpi_is_prime()

int mpi_is_prime	(	mpi *	X,
		int()(void , unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Miller-Rabin primality test.

Parameters

X	MPI to check
f_rng	RNG function
p_rng	RNG parameter

Returns: 0 if successful (probably prime), POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_NOT_ACCEPTABLE if X is not prime

◆ mpi_lsb()

size_t mpi_lsb ( const mpi * X )

Return the number of zero-bits before the least significant '1' bit.

Note: Thus also the zero-based index of the least significant '1' bit

Parameters

X	MPI to use

◆ mpi_lset()

int mpi_lset	(	mpi *	X,
		t_sint	z
	)

Set value from integer.

Parameters

X	MPI to set
z	Value to use

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_mod_int()

int mpi_mod_int	(	t_uint *	r,
		const mpi *	A,
		t_sint	b
	)

Modulo: r = A mod b.

Parameters

r	Destination t_uint
A	Left-hand MPI
b	Integer to divide by

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_DIVISION_BY_ZERO if b == 0, POLARSSL_ERR_MPI_NEGATIVE_VALUE if b < 0

◆ mpi_mod_mpi()

int mpi_mod_mpi	(	mpi *	R,
		const mpi *	A,
		const mpi *	B
	)

Modulo: R = A mod B.

Parameters

R	Destination MPI for the rest value
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_DIVISION_BY_ZERO if B == 0, POLARSSL_ERR_MPI_NEGATIVE_VALUE if B < 0

◆ mpi_msb()

size_t mpi_msb ( const mpi * X )

Return the number of bits up to and including the most significant '1' bit'.

Note: Thus also the one-based index of the most significant '1' bit

Parameters

X	MPI to use

Referenced by d2i_RSA_PUBKEY().

◆ mpi_mul_int()

int mpi_mul_int	(	mpi *	X,
		const mpi *	A,
		t_sint	b
	)

Baseline multiplication: X = A * b Note: despite the functon signature, b is treated as a t_uint.

Negative values of b are treated as large positive values.

Parameters

X	Destination MPI
A	Left-hand MPI
b	The integer value to multiply with

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_mul_mpi()

int mpi_mul_mpi	(	mpi *	X,
		const mpi *	A,
		const mpi *	B
	)

Baseline multiplication: X = A * B.

Parameters

X	Destination MPI
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_read_binary()

int mpi_read_binary	(	mpi *	X,
		const unsigned char *	buf,
		size_t	buflen
	)

Import X from unsigned binary data, big endian.

Parameters

X	Destination MPI
buf	Input buffer
buflen	Input buffer size

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

Referenced by d2i_RSA_PUBKEY().

◆ mpi_read_file()

int mpi_read_file	(	mpi *	X,
		int	radix,
		FILE *	fin
	)

Read X from an opened file.

Parameters

X	Destination MPI
radix	Input numeric base
fin	Input file handle

Returns: 0 if successful, POLARSSL_ERR_MPI_BUFFER_TOO_SMALL if the file read buffer is too small or a POLARSSL_ERR_MPI_XXX error code

◆ mpi_read_string()

int mpi_read_string	(	mpi *	X,
		int	radix,
		const char *	s
	)

Import from an ASCII string.

Parameters

X	Destination MPI
radix	Input numeric base
s	Null-terminated string buffer

Returns: 0 if successful, or a POLARSSL_ERR_MPI_XXX error code

◆ mpi_safe_cond_assign()

int mpi_safe_cond_assign	(	mpi *	X,
		const mpi *	Y,
		unsigned char	assign
	)

Safe conditional assignement X = Y if assign is 1.

Parameters

X	MPI to conditionally assign to
Y	Value to be assigned
assign	1: perform the assignment, 0: keep X's original value

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed,

Note: This function is equivalent to if( assign ) mpi_copy( X, Y ); except that it avoids leaking any information about whether the assignment was done or not (the above code may leak information through branch prediction and/or memory access patterns analysis).

◆ mpi_safe_cond_swap()

int mpi_safe_cond_swap	(	mpi *	X,
		mpi *	Y,
		unsigned char	assign
	)

Safe conditional swap X <-> Y if swap is 1.

Parameters

X	First mpi value
Y	Second mpi value
assign	1: perform the swap, 0: keep X and Y's original values

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed,

Note: This function is equivalent to if( assign ) mpi_swap( X, Y ); except that it avoids leaking any information about whether the assignment was done or not (the above code may leak information through branch prediction and/or memory access patterns analysis).

◆ mpi_self_test()

int mpi_self_test ( int verbose )

Checkup routine.

Returns: 0 if successful, or 1 if the test failed

◆ mpi_set_bit()

int mpi_set_bit	(	mpi *	X,
		size_t	pos,
		unsigned char	val
	)

Set a bit of X to a specific value of 0 or 1.

Note: Will grow X if necessary to set a bit to 1 in a not yet existing limb. Will not grow if bit should be set to 0

Parameters

X	MPI to use
pos	Zero-based index of the bit in X
val	The value to set the bit to (0 or 1)

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed, POLARSSL_ERR_MPI_BAD_INPUT_DATA if val is not 0 or 1

◆ mpi_shift_l()

int mpi_shift_l	(	mpi *	X,
		size_t	count
	)

Left-shift: X <<= count.

Parameters

X	MPI to shift
count	Amount to shift

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_shift_r()

int mpi_shift_r	(	mpi *	X,
		size_t	count
	)

Right-shift: X >>= count.

Parameters

X	MPI to shift
count	Amount to shift

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_shrink()

int mpi_shrink	(	mpi *	X,
		size_t	nblimbs
	)

Resize down, keeping at least the specified number of limbs.

Parameters

X	MPI to shrink
nblimbs	The minimum number of limbs to keep

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_size()

size_t mpi_size ( const mpi * X )

Return the total size in bytes.

Parameters

X	MPI to use

◆ mpi_sub_abs()

int mpi_sub_abs	(	mpi *	X,
		const mpi *	A,
		const mpi *	B
	)

Unsigned subtraction: X = |A| - |B|.

Parameters

X	Destination MPI
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_NEGATIVE_VALUE if B is greater than A

◆ mpi_sub_int()

int mpi_sub_int	(	mpi *	X,
		const mpi *	A,
		t_sint	b
	)

Signed subtraction: X = A - b.

Parameters

X	Destination MPI
A	Left-hand MPI
b	The integer value to subtract

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_sub_mpi()

int mpi_sub_mpi	(	mpi *	X,
		const mpi *	A,
		const mpi *	B
	)

Signed subtraction: X = A - B.

Parameters

X	Destination MPI
A	Left-hand MPI
B	Right-hand MPI

Returns: 0 if successful, POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed

◆ mpi_swap()

void mpi_swap	(	mpi *	X,
		mpi *	Y
	)

Swap the contents of X and Y.

Parameters

X	First MPI value
Y	Second MPI value

◆ mpi_write_binary()

int mpi_write_binary	(	const mpi *	X,
		unsigned char *	buf,
		size_t	buflen
	)

Export X into unsigned binary data, big endian.

Always fills the whole buffer, which will start with zeros if the number is smaller.

Parameters

X	Source MPI
buf	Output buffer
buflen	Output buffer size

Returns: 0 if successful, POLARSSL_ERR_MPI_BUFFER_TOO_SMALL if buf isn't large enough

◆ mpi_write_file()

int mpi_write_file	(	const char *	p,
		const mpi *	X,
		int	radix,
		FILE *	fout
	)

Write X into an opened file, or stdout if fout is NULL.

Parameters

p	Prefix, can be NULL
X	Source MPI
radix	Output numeric base
fout	Output file handle (can be NULL)

Returns: 0 if successful, or a POLARSSL_ERR_MPI_XXX error code

Note: Set fout == NULL to print X on the console.

◆ mpi_write_string()

int mpi_write_string	(	const mpi *	X,
		int	radix,
		char *	s,
		size_t *	slen
	)

Export into an ASCII string.

Parameters

X	Source MPI
radix	Output numeric base
s	String buffer
slen	String buffer size

Returns: 0 if successful, or a POLARSSL_ERR_MPI_XXX error code. *slen is always updated to reflect the amount of data that has (or would have) been written.

Note: Call this function with *slen = 0 to obtain the minimum required buffer size in *slen.

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ LN_2_DIV_LN_10_SCALE100

◆ MPI_CHK

◆ POLARSSL_ERR_MPI_BAD_INPUT_DATA

◆ POLARSSL_ERR_MPI_BUFFER_TOO_SMALL

◆ POLARSSL_ERR_MPI_DIVISION_BY_ZERO

◆ POLARSSL_ERR_MPI_FILE_IO_ERROR

◆ POLARSSL_ERR_MPI_INVALID_CHARACTER

◆ POLARSSL_ERR_MPI_MALLOC_FAILED

◆ POLARSSL_ERR_MPI_NEGATIVE_VALUE

◆ POLARSSL_ERR_MPI_NOT_ACCEPTABLE

◆ POLARSSL_HAVE_INT32

◆ POLARSSL_HAVE_UDBL

◆ POLARSSL_MPI_MAX_BITS

◆ POLARSSL_MPI_MAX_BITS_SCALE100

◆ POLARSSL_MPI_MAX_LIMBS

◆ POLARSSL_MPI_MAX_SIZE

◆ POLARSSL_MPI_RW_BUFFER_SIZE

◆ POLARSSL_MPI_WINDOW_SIZE

Typedef Documentation

◆ t_sint

◆ t_udbl

◆ t_uint

Function Documentation

◆ mpi_add_abs()

◆ mpi_add_int()

◆ mpi_add_mpi()

◆ mpi_cmp_abs()

◆ mpi_cmp_int()

◆ mpi_cmp_mpi()

◆ mpi_copy()

◆ mpi_div_int()

◆ mpi_div_mpi()

◆ mpi_exp_mod()

◆ mpi_fill_random()

◆ mpi_free()

◆ mpi_gcd()

◆ mpi_gen_prime()

◆ mpi_get_bit()

◆ mpi_grow()

◆ mpi_init()

◆ mpi_inv_mod()

◆ mpi_is_prime()

◆ mpi_lsb()

◆ mpi_lset()

◆ mpi_mod_int()

◆ mpi_mod_mpi()

◆ mpi_msb()

◆ mpi_mul_int()

◆ mpi_mul_mpi()

◆ mpi_read_binary()

◆ mpi_read_file()

◆ mpi_read_string()

◆ mpi_safe_cond_assign()

◆ mpi_safe_cond_swap()

◆ mpi_self_test()

◆ mpi_set_bit()

◆ mpi_shift_l()

◆ mpi_shift_r()

◆ mpi_shrink()

◆ mpi_size()

◆ mpi_sub_abs()

◆ mpi_sub_int()

◆ mpi_sub_mpi()

◆ mpi_swap()

◆ mpi_write_binary()

◆ mpi_write_file()

◆ mpi_write_string()