bignum.h File Reference

Multi-precision integer library. More...

#include "config.h"
#include <stddef.h>
#include <stdint.h>
Include dependency graph for bignum.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures

struct  mbedtls_mpi
 MPI structure. More...

Defines

#define MBEDTLS_ERR_MPI_FILE_IO_ERROR   -0x0002
#define MBEDTLS_ERR_MPI_BAD_INPUT_DATA   -0x0004
#define MBEDTLS_ERR_MPI_INVALID_CHARACTER   -0x0006
#define MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL   -0x0008
#define MBEDTLS_ERR_MPI_NEGATIVE_VALUE   -0x000A
#define MBEDTLS_ERR_MPI_DIVISION_BY_ZERO   -0x000C
#define MBEDTLS_ERR_MPI_NOT_ACCEPTABLE   -0x000E
#define MBEDTLS_ERR_MPI_ALLOC_FAILED   -0x0010
#define MBEDTLS_MPI_CHK(f)   do { if( ( ret = f ) != 0 ) goto cleanup; } while( 0 )
#define MBEDTLS_MPI_MAX_LIMBS   10000
#define MBEDTLS_MPI_WINDOW_SIZE   6
#define MBEDTLS_MPI_MAX_SIZE   1024
#define MBEDTLS_MPI_MAX_BITS   ( 8 * MBEDTLS_MPI_MAX_SIZE )
#define MBEDTLS_MPI_MAX_BITS_SCALE100   ( 100 * MBEDTLS_MPI_MAX_BITS )
#define MBEDTLS_LN_2_DIV_LN_10_SCALE100   332
#define MBEDTLS_MPI_RW_BUFFER_SIZE   ( ((MBEDTLS_MPI_MAX_BITS_SCALE100 + MBEDTLS_LN_2_DIV_LN_10_SCALE100 - 1) / MBEDTLS_LN_2_DIV_LN_10_SCALE100) + 10 + 6 )
#define MBEDTLS_HAVE_INT32
#define MBEDTLS_HAVE_UDBL

Typedefs

typedef int32_t mbedtls_mpi_sint
typedef uint32_t mbedtls_mpi_uint
typedef uint64_t mbedtls_t_udbl

Functions

void mbedtls_mpi_init (mbedtls_mpi *X)
 Initialize one MPI (make internal references valid) This just makes it ready to be set or freed, but does not define a value for the MPI.
void mbedtls_mpi_free (mbedtls_mpi *X)
 Unallocate one MPI.
int mbedtls_mpi_grow (mbedtls_mpi *X, size_t nblimbs)
 Enlarge to the specified number of limbs.
int mbedtls_mpi_shrink (mbedtls_mpi *X, size_t nblimbs)
 Resize down, keeping at least the specified number of limbs.
int mbedtls_mpi_copy (mbedtls_mpi *X, const mbedtls_mpi *Y)
 Copy the contents of Y into X.
void mbedtls_mpi_swap (mbedtls_mpi *X, mbedtls_mpi *Y)
 Swap the contents of X and Y.
int mbedtls_mpi_safe_cond_assign (mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned char assign)
 Safe conditional assignement X = Y if assign is 1.
int mbedtls_mpi_safe_cond_swap (mbedtls_mpi *X, mbedtls_mpi *Y, unsigned char assign)
 Safe conditional swap X <-> Y if swap is 1.
int mbedtls_mpi_lset (mbedtls_mpi *X, mbedtls_mpi_sint z)
 Set value from integer.
int mbedtls_mpi_get_bit (const mbedtls_mpi *X, size_t pos)
 Get a specific bit from X.
int mbedtls_mpi_set_bit (mbedtls_mpi *X, size_t pos, unsigned char val)
 Set a bit of X to a specific value of 0 or 1.
size_t mbedtls_mpi_lsb (const mbedtls_mpi *X)
 Return the number of zero-bits before the least significant '1' bit.
size_t mbedtls_mpi_bitlen (const mbedtls_mpi *X)
 Return the number of bits up to and including the most significant '1' bit'.
size_t mbedtls_mpi_size (const mbedtls_mpi *X)
 Return the total size in bytes.
int mbedtls_mpi_read_string (mbedtls_mpi *X, int radix, const char *s)
 Import from an ASCII string.
int mbedtls_mpi_write_string (const mbedtls_mpi *X, int radix, char *buf, size_t buflen, size_t *olen)
 Export into an ASCII string.
int mbedtls_mpi_read_binary (mbedtls_mpi *X, const unsigned char *buf, size_t buflen)
 Import X from unsigned binary data, big endian.
int mbedtls_mpi_write_binary (const mbedtls_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.
int mbedtls_mpi_shift_l (mbedtls_mpi *X, size_t count)
 Left-shift: X <<= count.
int mbedtls_mpi_shift_r (mbedtls_mpi *X, size_t count)
 Right-shift: X >>= count.
int mbedtls_mpi_cmp_abs (const mbedtls_mpi *X, const mbedtls_mpi *Y)
 Compare unsigned values.
int mbedtls_mpi_cmp_mpi (const mbedtls_mpi *X, const mbedtls_mpi *Y)
 Compare signed values.
int mbedtls_mpi_lt_mpi_ct (const mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned *ret)
 Check if an MPI is less than the other in constant time.
int mbedtls_mpi_cmp_int (const mbedtls_mpi *X, mbedtls_mpi_sint z)
 Compare signed values.
int mbedtls_mpi_add_abs (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Unsigned addition: X = |A| + |B|.
int mbedtls_mpi_sub_abs (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Unsigned subtraction: X = |A| - |B|.
int mbedtls_mpi_add_mpi (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Signed addition: X = A + B.
int mbedtls_mpi_sub_mpi (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Signed subtraction: X = A - B.
int mbedtls_mpi_add_int (mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b)
 Signed addition: X = A + b.
int mbedtls_mpi_sub_int (mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b)
 Signed subtraction: X = A - b.
int mbedtls_mpi_mul_mpi (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Baseline multiplication: X = A * B.
int mbedtls_mpi_mul_int (mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_uint b)
 Baseline multiplication: X = A * b.
int mbedtls_mpi_div_mpi (mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Division by mbedtls_mpi: A = Q * B + R.
int mbedtls_mpi_div_int (mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, mbedtls_mpi_sint b)
 Division by int: A = Q * b + R.
int mbedtls_mpi_mod_mpi (mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Modulo: R = A mod B.
int mbedtls_mpi_mod_int (mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_sint b)
 Modulo: r = A mod b.
int mbedtls_mpi_exp_mod (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *E, const mbedtls_mpi *N, mbedtls_mpi *_RR)
 Sliding-window exponentiation: X = A^E mod N.
int mbedtls_mpi_fill_random (mbedtls_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 mbedtls_mpi_gcd (mbedtls_mpi *G, const mbedtls_mpi *A, const mbedtls_mpi *B)
 Greatest common divisor: G = gcd(A, B).
int mbedtls_mpi_inv_mod (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *N)
 Modular inverse: X = A^-1 mod N.
int mbedtls_mpi_is_prime (const mbedtls_mpi *X, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
 Miller-Rabin primality test.
int mbedtls_mpi_gen_prime (mbedtls_mpi *X, size_t nbits, int dh_flag, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
 Prime number generation.
int mbedtls_mpi_self_test (int verbose)
 Checkup routine.

Detailed Description

Multi-precision integer library.

Definition in file bignum.h.


Define Documentation

#define MBEDTLS_ERR_MPI_ALLOC_FAILED   -0x0010

Memory allocation failed.

Definition at line 74 of file bignum.h.

#define MBEDTLS_ERR_MPI_BAD_INPUT_DATA   -0x0004

Bad input parameters to function.

Definition at line 68 of file bignum.h.

#define MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL   -0x0008

The buffer is too small to write to.

Definition at line 70 of file bignum.h.

#define MBEDTLS_ERR_MPI_DIVISION_BY_ZERO   -0x000C

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

Definition at line 72 of file bignum.h.

#define MBEDTLS_ERR_MPI_FILE_IO_ERROR   -0x0002

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

Definition at line 67 of file bignum.h.

#define MBEDTLS_ERR_MPI_INVALID_CHARACTER   -0x0006

There is an invalid character in the digit string.

Definition at line 69 of file bignum.h.

#define MBEDTLS_ERR_MPI_NEGATIVE_VALUE   -0x000A

The input arguments are negative or result in illegal output.

Definition at line 71 of file bignum.h.

#define MBEDTLS_ERR_MPI_NOT_ACCEPTABLE   -0x000E

The input arguments are not acceptable.

Definition at line 73 of file bignum.h.

#define MBEDTLS_HAVE_INT32

Definition at line 190 of file bignum.h.

#define MBEDTLS_HAVE_UDBL

Definition at line 196 of file bignum.h.

#define MBEDTLS_LN_2_DIV_LN_10_SCALE100   332

Definition at line 128 of file bignum.h.

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

Definition at line 76 of file bignum.h.

#define MBEDTLS_MPI_MAX_BITS   ( 8 * MBEDTLS_MPI_MAX_SIZE )

Maximum number of bits for usable MPIs.

Definition at line 107 of file bignum.h.

#define MBEDTLS_MPI_MAX_BITS_SCALE100   ( 100 * MBEDTLS_MPI_MAX_BITS )

Definition at line 127 of file bignum.h.

#define MBEDTLS_MPI_MAX_LIMBS   10000

Definition at line 81 of file bignum.h.

#define MBEDTLS_MPI_MAX_SIZE   1024

Maximum number of bytes for usable MPIs.

Definition at line 104 of file bignum.h.

#define MBEDTLS_MPI_RW_BUFFER_SIZE   ( ((MBEDTLS_MPI_MAX_BITS_SCALE100 + MBEDTLS_LN_2_DIV_LN_10_SCALE100 - 1) / MBEDTLS_LN_2_DIV_LN_10_SCALE100) + 10 + 6 )

Definition at line 129 of file bignum.h.

#define MBEDTLS_MPI_WINDOW_SIZE   6

Maximum windows size used.

Definition at line 93 of file bignum.h.


Typedef Documentation

typedef int32_t mbedtls_mpi_sint

Definition at line 192 of file bignum.h.

typedef uint32_t mbedtls_mpi_uint

Definition at line 193 of file bignum.h.

typedef uint64_t mbedtls_t_udbl

Definition at line 195 of file bignum.h.


Function Documentation

int mbedtls_mpi_add_abs ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_mpi B 
)

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

Parameters:
X Destination MPI
A Left-hand MPI
B Right-hand MPI
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_add_int ( mbedtls_mpi X,
const mbedtls_mpi A,
mbedtls_mpi_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_add_mpi ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_mpi B 
)

Signed addition: X = A + B.

Parameters:
X Destination MPI
A Left-hand MPI
B Right-hand MPI
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
size_t mbedtls_mpi_bitlen ( const mbedtls_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
int mbedtls_mpi_cmp_abs ( const mbedtls_mpi X,
const mbedtls_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|
int mbedtls_mpi_cmp_int ( const mbedtls_mpi X,
mbedtls_mpi_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
int mbedtls_mpi_cmp_mpi ( const mbedtls_mpi X,
const mbedtls_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
int mbedtls_mpi_copy ( mbedtls_mpi X,
const mbedtls_mpi Y 
)

Copy the contents of Y into X.

Parameters:
X Destination MPI
Y Source MPI
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_div_int ( mbedtls_mpi Q,
mbedtls_mpi R,
const mbedtls_mpi A,
mbedtls_mpi_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if b == 0
Note:
Either Q or R can be NULL.
int mbedtls_mpi_div_mpi ( mbedtls_mpi Q,
mbedtls_mpi R,
const mbedtls_mpi A,
const mbedtls_mpi B 
)

Division by mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if B == 0
Note:
Either Q or R can be NULL.
int mbedtls_mpi_exp_mod ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_mpi E,
const mbedtls_mpi N,
mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_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.
int mbedtls_mpi_fill_random ( mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
Note:
The bytes obtained from the PRNG are interpreted as a big-endian representation of an MPI; this can be relevant in applications like deterministic ECDSA.
void mbedtls_mpi_free ( mbedtls_mpi X  ) 

Unallocate one MPI.

Parameters:
X One MPI to unallocate.
int mbedtls_mpi_gcd ( mbedtls_mpi G,
const mbedtls_mpi A,
const mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_gen_prime ( mbedtls_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 <= MBEDTLS_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), MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_BAD_INPUT_DATA if nbits is < 3
int mbedtls_mpi_get_bit ( const mbedtls_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
int mbedtls_mpi_grow ( mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
void mbedtls_mpi_init ( mbedtls_mpi X  ) 

Initialize one MPI (make internal references valid) This just makes it ready to be set or freed, but does not define a value for the MPI.

Parameters:
X One MPI to initialize.
int mbedtls_mpi_inv_mod ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_BAD_INPUT_DATA if N is <= 1, MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if A has no inverse mod N.
int mbedtls_mpi_is_prime ( const mbedtls_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), MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if X is not prime
size_t mbedtls_mpi_lsb ( const mbedtls_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
int mbedtls_mpi_lset ( mbedtls_mpi X,
mbedtls_mpi_sint  z 
)

Set value from integer.

Parameters:
X MPI to set
z Value to use
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_lt_mpi_ct ( const mbedtls_mpi X,
const mbedtls_mpi Y,
unsigned *  ret 
)

Check if an MPI is less than the other in constant time.

Parameters:
X The left-hand MPI. This must point to an initialized MPI with the same allocated length as Y.
Y The right-hand MPI. This must point to an initialized MPI with the same allocated length as X.
ret The result of the comparison: 1 if X is less than Y. 0 if X is greater than or equal to Y.
Returns:
0 on success.
MBEDTLS_ERR_MPI_BAD_INPUT_DATA if the allocated length of the two input MPIs is not the same.
int mbedtls_mpi_mod_int ( mbedtls_mpi_uint r,
const mbedtls_mpi A,
mbedtls_mpi_sint  b 
)

Modulo: r = A mod b.

Parameters:
r Destination mbedtls_mpi_uint
A Left-hand MPI
b Integer to divide by
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if b == 0, MBEDTLS_ERR_MPI_NEGATIVE_VALUE if b < 0
int mbedtls_mpi_mod_mpi ( mbedtls_mpi R,
const mbedtls_mpi A,
const mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if B == 0, MBEDTLS_ERR_MPI_NEGATIVE_VALUE if B < 0
int mbedtls_mpi_mul_int ( mbedtls_mpi X,
const mbedtls_mpi A,
mbedtls_mpi_uint  b 
)

Baseline multiplication: X = A * b.

Parameters:
X Destination MPI
A Left-hand MPI
b The unsigned integer value to multiply with
Note:
b is unsigned
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_mul_mpi ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_mpi B 
)

Baseline multiplication: X = A * B.

Parameters:
X Destination MPI
A Left-hand MPI
B Right-hand MPI
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_read_binary ( mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_read_string ( mbedtls_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 MBEDTLS_ERR_MPI_XXX error code
int mbedtls_mpi_safe_cond_assign ( mbedtls_mpi X,
const mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
Note:
This function is equivalent to if( assign ) mbedtls_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).
int mbedtls_mpi_safe_cond_swap ( mbedtls_mpi X,
mbedtls_mpi Y,
unsigned char  assign 
)

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

Parameters:
X First mbedtls_mpi value
Y Second mbedtls_mpi value
assign 1: perform the swap, 0: keep X and Y's original values
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
Note:
This function is equivalent to if( assign ) mbedtls_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).
int mbedtls_mpi_self_test ( int  verbose  ) 

Checkup routine.

Returns:
0 if successful, or 1 if the test failed
int mbedtls_mpi_set_bit ( mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_MPI_BAD_INPUT_DATA if val is not 0 or 1
int mbedtls_mpi_shift_l ( mbedtls_mpi X,
size_t  count 
)

Left-shift: X <<= count.

Parameters:
X MPI to shift
count Amount to shift
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_shift_r ( mbedtls_mpi X,
size_t  count 
)

Right-shift: X >>= count.

Parameters:
X MPI to shift
count Amount to shift
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_shrink ( mbedtls_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
size_t mbedtls_mpi_size ( const mbedtls_mpi X  ) 

Return the total size in bytes.

Parameters:
X MPI to use
int mbedtls_mpi_sub_abs ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_mpi B 
)

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

Parameters:
X Destination MPI
A Left-hand MPI
B Right-hand MPI
Returns:
0 if successful, MBEDTLS_ERR_MPI_NEGATIVE_VALUE if B is greater than A
int mbedtls_mpi_sub_int ( mbedtls_mpi X,
const mbedtls_mpi A,
mbedtls_mpi_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, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
int mbedtls_mpi_sub_mpi ( mbedtls_mpi X,
const mbedtls_mpi A,
const mbedtls_mpi B 
)

Signed subtraction: X = A - B.

Parameters:
X Destination MPI
A Left-hand MPI
B Right-hand MPI
Returns:
0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
void mbedtls_mpi_swap ( mbedtls_mpi X,
mbedtls_mpi Y 
)

Swap the contents of X and Y.

Parameters:
X First MPI value
Y Second MPI value
int mbedtls_mpi_write_binary ( const mbedtls_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, MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if buf isn't large enough
int mbedtls_mpi_write_string ( const mbedtls_mpi X,
int  radix,
char *  buf,
size_t  buflen,
size_t *  olen 
)

Export into an ASCII string.

Parameters:
X Source MPI
radix Output numeric base
buf Buffer to write the string to
buflen Length of buf
olen Length of the string written, including final NUL byte
Returns:
0 if successful, or a MBEDTLS_ERR_MPI_XXX error code. *olen is always updated to reflect the amount of data that has (or would have) been written.
Note:
Call this function with buflen = 0 to obtain the minimum required buffer size in *olen.

Generated on 10 Aug 2020 for mbed TLS v2.7.16 by  doxygen 1.6.1