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Dependents: TYBLE16_simple_data_logger TYBLE16_MP3_Air
bignum.h File Reference
Multi-precision integer library. More...
Go to the source code of this file.
Data Structures | |
struct | mbedtls_mpi |
MPI structure. More... | |
Typedefs | |
typedef struct mbedtls_mpi | mbedtls_mpi |
MPI structure. | |
Enumerations | |
enum | mbedtls_mpi_gen_prime_flag_t { MBEDTLS_MPI_GEN_PRIME_FLAG_DH = 0x0001, MBEDTLS_MPI_GEN_PRIME_FLAG_LOW_ERR = 0x0002 } |
Flags for mbedtls_mpi_gen_prime() More... | |
Functions | |
void | mbedtls_mpi_init (mbedtls_mpi *X) |
Initialize an MPI context. | |
void | mbedtls_mpi_free (mbedtls_mpi *X) |
This function frees the components of an MPI context. | |
int | mbedtls_mpi_grow (mbedtls_mpi *X, size_t nblimbs) |
Enlarge an MPI to the specified number of limbs. | |
int | mbedtls_mpi_shrink (mbedtls_mpi *X, size_t nblimbs) |
This function resizes an MPI downwards, keeping at least the specified number of limbs. | |
int | mbedtls_mpi_copy (mbedtls_mpi *X, const mbedtls_mpi *Y) |
Make a copy of an MPI. | |
void | mbedtls_mpi_swap (mbedtls_mpi *X, mbedtls_mpi *Y) |
Swap the contents of two MPIs. | |
int | mbedtls_mpi_safe_cond_assign (mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned char assign) |
Perform a safe conditional copy of MPI which doesn't reveal whether the condition was true or not. | |
int | mbedtls_mpi_safe_cond_swap (mbedtls_mpi *X, mbedtls_mpi *Y, unsigned char assign) |
Perform a safe conditional swap which doesn't reveal whether the condition was true or not. | |
int | mbedtls_mpi_lset (mbedtls_mpi *X, mbedtls_mpi_sint z) |
Store integer value in MPI. | |
int | mbedtls_mpi_get_bit (const mbedtls_mpi *X, size_t pos) |
Get a specific bit from an MPI. | |
int | mbedtls_mpi_set_bit (mbedtls_mpi *X, size_t pos, unsigned char val) |
Modify a specific bit in an MPI. | |
size_t | mbedtls_mpi_lsb (const mbedtls_mpi *X) |
Return the number of bits of value 0 before the least significant bit of value 1 . | |
size_t | mbedtls_mpi_bitlen (const mbedtls_mpi *X) |
Return the number of bits up to and including the most significant bit of value 1 . | |
size_t | mbedtls_mpi_size (const mbedtls_mpi *X) |
Return the total size of an MPI value in bytes. | |
int | mbedtls_mpi_read_string (mbedtls_mpi *X, int radix, const char *s) |
Import an MPI from an ASCII string. | |
int | mbedtls_mpi_write_string (const mbedtls_mpi *X, int radix, char *buf, size_t buflen, size_t *olen) |
Export an MPI to an ASCII string. | |
int | mbedtls_mpi_read_file (mbedtls_mpi *X, int radix, FILE *fin) |
Read an MPI from a line in an opened file. | |
int | mbedtls_mpi_write_file (const char *p, const mbedtls_mpi *X, int radix, FILE *fout) |
Export an MPI into an opened file. | |
int | mbedtls_mpi_read_binary (mbedtls_mpi *X, const unsigned char *buf, size_t buflen) |
Import an MPI from unsigned big endian binary data. | |
int | mbedtls_mpi_read_binary_le (mbedtls_mpi *X, const unsigned char *buf, size_t buflen) |
Import X from unsigned binary data, little endian. | |
int | mbedtls_mpi_write_binary (const mbedtls_mpi *X, unsigned char *buf, size_t buflen) |
Export X into unsigned binary data, big endian. | |
int | mbedtls_mpi_write_binary_le (const mbedtls_mpi *X, unsigned char *buf, size_t buflen) |
Export X into unsigned binary data, little endian. | |
int | mbedtls_mpi_shift_l (mbedtls_mpi *X, size_t count) |
Perform a left-shift on an MPI: X <<= count. | |
int | mbedtls_mpi_shift_r (mbedtls_mpi *X, size_t count) |
Perform a right-shift on an MPI: X >>= count. | |
int | mbedtls_mpi_cmp_abs (const mbedtls_mpi *X, const mbedtls_mpi *Y) |
Compare the absolute values of two MPIs. | |
int | mbedtls_mpi_cmp_mpi (const mbedtls_mpi *X, const mbedtls_mpi *Y) |
Compare two MPIs. | |
int | mbedtls_mpi_cmp_int (const mbedtls_mpi *X, mbedtls_mpi_sint z) |
Compare an MPI with an integer. | |
int | mbedtls_mpi_add_abs (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform an unsigned addition of MPIs: X = |A| + |B|. | |
int | mbedtls_mpi_sub_abs (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform an unsigned subtraction of MPIs: X = |A| - |B|. | |
int | mbedtls_mpi_add_mpi (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform a signed addition of MPIs: X = A + B. | |
int | mbedtls_mpi_sub_mpi (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform a signed subtraction of MPIs: X = A - B. | |
int | mbedtls_mpi_add_int (mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b) |
Perform a signed addition of an MPI and an integer: X = A + b. | |
int | mbedtls_mpi_sub_int (mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b) |
Perform a signed subtraction of an MPI and an integer: X = A - b. | |
int | mbedtls_mpi_mul_mpi (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform a multiplication of two MPIs: X = A * B. | |
int | mbedtls_mpi_mul_int (mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_uint b) |
Perform a multiplication of an MPI with an unsigned integer: X = A * b. | |
int | mbedtls_mpi_div_mpi (mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform a division with remainder of two MPIs: A = Q * B + R. | |
int | mbedtls_mpi_div_int (mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, mbedtls_mpi_sint b) |
Perform a division with remainder of an MPI by an integer: A = Q * b + R. | |
int | mbedtls_mpi_mod_mpi (mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Perform a modular reduction. | |
int | mbedtls_mpi_mod_int (mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_sint b) |
Perform a modular reduction with respect to an integer. | |
int | mbedtls_mpi_exp_mod (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *E, const mbedtls_mpi *N, mbedtls_mpi *_RR) |
Perform a 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 with a number of random bytes. | |
int | mbedtls_mpi_gcd (mbedtls_mpi *G, const mbedtls_mpi *A, const mbedtls_mpi *B) |
Compute the greatest common divisor: G = gcd(A, B) | |
int | mbedtls_mpi_inv_mod (mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *N) |
Compute the modular inverse: X = A^-1 mod N. | |
MBEDTLS_DEPRECATED int | mbedtls_mpi_is_prime (const mbedtls_mpi *X, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng) |
Perform a Miller-Rabin primality test with error probability of 2-80. | |
int | mbedtls_mpi_is_prime_ext (const mbedtls_mpi *X, int rounds, 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 flags, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng) |
Generate a prime number. | |
int | mbedtls_mpi_self_test (int verbose) |
Checkup routine. |
Detailed Description
Multi-precision integer library.
Definition in file bignum.h.
Typedef Documentation
typedef struct mbedtls_mpi mbedtls_mpi |
MPI structure.
Enumeration Type Documentation
Flags for mbedtls_mpi_gen_prime()
Each of these flags is a constraint on the result X returned by mbedtls_mpi_gen_prime().
Function Documentation
int mbedtls_mpi_add_abs | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform an unsigned addition of MPIs: X = |A| + |B|.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The first summand. This must point to an initialized MPI. B The second summand. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_add_int | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
mbedtls_mpi_sint | b | ||
) |
Perform a signed addition of an MPI and an integer: X = A + b.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The first summand. This must point to an initialized MPI. b The second summand.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_add_mpi | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform a signed addition of MPIs: X = A + B.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The first summand. This must point to an initialized MPI. B The second summand. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
size_t mbedtls_mpi_bitlen | ( | const mbedtls_mpi * | X ) |
Return the number of bits up to and including the most significant bit of value 1
.
*
- Note:
- This is same as the one-based index of the most significant bit of value
1
.
- Parameters:
-
X The MPI to query. This must point to an initialized MPI.
- Returns:
- The number of bits up to and including the most significant bit of value
1
.
int mbedtls_mpi_cmp_abs | ( | const mbedtls_mpi * | X, |
const mbedtls_mpi * | Y | ||
) |
Compare the absolute values of two MPIs.
- Parameters:
-
X The left-hand MPI. This must point to an initialized MPI. Y The right-hand MPI. This must point to an initialized MPI.
- Returns:
1
if `|X|` is greater than `|Y|`.-
-1
if `|X|` is lesser than `|Y|`. -
0
if `|X|` is equal to `|Y|`.
int mbedtls_mpi_cmp_int | ( | const mbedtls_mpi * | X, |
mbedtls_mpi_sint | z | ||
) |
int mbedtls_mpi_cmp_mpi | ( | const mbedtls_mpi * | X, |
const mbedtls_mpi * | Y | ||
) |
int mbedtls_mpi_copy | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | Y | ||
) |
Make a copy of an MPI.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. Y The source MPI. This must point to an initialized MPI.
- Note:
- The limb-buffer in the destination MPI is enlarged if necessary to hold the value in the source MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on other kinds of failure.
int mbedtls_mpi_div_int | ( | mbedtls_mpi * | Q, |
mbedtls_mpi * | R, | ||
const mbedtls_mpi * | A, | ||
mbedtls_mpi_sint | b | ||
) |
Perform a division with remainder of an MPI by an integer: A = Q * b + R.
- Parameters:
-
Q The destination MPI for the quotient. This may be NULL
if the value of the quotient is not needed.R The destination MPI for the remainder value. This may be NULL
if the value of the remainder is not needed.A The dividend. This must point to an initialized MPi. b The divisor.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
-
MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if
b
equals zero. - Another negative error code on different kinds of failure.
int mbedtls_mpi_div_mpi | ( | mbedtls_mpi * | Q, |
mbedtls_mpi * | R, | ||
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform a division with remainder of two MPIs: A = Q * B + R.
- Parameters:
-
Q The destination MPI for the quotient. This may be NULL
if the value of the quotient is not needed.R The destination MPI for the remainder value. This may be NULL
if the value of the remainder is not needed.A The dividend. This must point to an initialized MPi. B The divisor. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
-
MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if
B
equals zero. - Another negative error code on different kinds of failure.
int mbedtls_mpi_exp_mod | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | E, | ||
const mbedtls_mpi * | N, | ||
mbedtls_mpi * | _RR | ||
) |
Perform a sliding-window exponentiation: X = A^E mod N.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The base of the exponentiation. This must point to an initialized MPI. E The exponent MPI. This must point to an initialized MPI. N The base for the modular reduction. This must point to an initialized MPI. _RR A helper MPI depending solely on N
which can be used to speed-up multiple modular exponentiations for the same value ofN
. This may beNULL
. If it is notNULL
, it must point to an initialized MPI. If it hasn't been used after the call to mbedtls_mpi_init(), this function will compute the helper value and store it in_RR
for reuse on subsequent calls to this function. Otherwise, the function will assume that_RR
holds the helper value set by a previous call to mbedtls_mpi_exp_mod(), and reuse it.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_BAD_INPUT_DATA if
N
is negative or even, or ifE
is negative. - Another negative error code on different kinds of failures.
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 with a number of random bytes.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. size The number of random bytes to generate. f_rng The RNG function to use. This must not be NULL
.p_rng The RNG parameter to be passed to f_rng
. This may beNULL
iff_rng
doesn't need a context argument.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on failure.
- Note:
- The bytes obtained from the RNG 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 ) |
int mbedtls_mpi_gcd | ( | mbedtls_mpi * | G, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Compute the greatest common divisor: G = gcd(A, B)
- Parameters:
-
G The destination MPI. This must point to an initialized MPI. A The first operand. This must point to an initialized MPI. B The second operand. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_gen_prime | ( | mbedtls_mpi * | X, |
size_t | nbits, | ||
int | flags, | ||
int(*)(void *, unsigned char *, size_t) | f_rng, | ||
void * | p_rng | ||
) |
Generate a prime number.
- Parameters:
-
X The destination MPI to store the generated prime in. This must point to an initialized MPi. nbits The required size of the destination MPI in bits. This must be between 3
and MBEDTLS_MPI_MAX_BITS.flags A mask of flags of type mbedtls_mpi_gen_prime_flag_t. f_rng The RNG function to use. This must not be NULL
.p_rng The RNG parameter to be passed to f_rng
. This may beNULL
iff_rng
doesn't use a context parameter.
- Returns:
0
if successful, in which caseX
holds a probably prime number.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_BAD_INPUT_DATA if `nbits` is not between
3
and MBEDTLS_MPI_MAX_BITS.
int mbedtls_mpi_get_bit | ( | const mbedtls_mpi * | X, |
size_t | pos | ||
) |
int mbedtls_mpi_grow | ( | mbedtls_mpi * | X, |
size_t | nblimbs | ||
) |
Enlarge an MPI to the specified number of limbs.
- Note:
- This function does nothing if the MPI is already large enough.
- Parameters:
-
X The MPI to grow. It must be initialized. nblimbs The target number of limbs.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on other kinds of failure.
void mbedtls_mpi_init | ( | mbedtls_mpi * | X ) |
int mbedtls_mpi_inv_mod | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | N | ||
) |
Compute the modular inverse: X = A^-1 mod N.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The MPI to calculate the modular inverse of. This must point to an initialized MPI. N The base of the modular inversion. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_BAD_INPUT_DATA if
N
is less than or equal to one. -
MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if
has
no modular inverse with respect toN
.
MBEDTLS_DEPRECATED int mbedtls_mpi_is_prime | ( | const mbedtls_mpi * | X, |
int(*)(void *, unsigned char *, size_t) | f_rng, | ||
void * | p_rng | ||
) |
Perform a Miller-Rabin primality test with error probability of 2-80.
- Parameters:
-
X The MPI to check for primality. This must point to an initialized MPI. f_rng The RNG function to use. This must not be NULL
.p_rng The RNG parameter to be passed to f_rng
. This may beNULL
iff_rng
doesn't use a context parameter.
- Returns:
0
if successful, i.e.X
is probably prime.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if
X
is not prime. - Another negative error code on other kinds of failure.
int mbedtls_mpi_is_prime_ext | ( | const mbedtls_mpi * | X, |
int | rounds, | ||
int(*)(void *, unsigned char *, size_t) | f_rng, | ||
void * | p_rng | ||
) |
Miller-Rabin primality test.
- Warning:
- If
X
is potentially generated by an adversary, for example when validating cryptographic parameters that you didn't generate yourself and that are supposed to be prime, thenrounds
should be at least the half of the security strength of the cryptographic algorithm. On the other hand, ifX
is chosen uniformly or non-adversially (as is the case when mbedtls_mpi_gen_prime calls this function), thenrounds
can be much lower.
- Parameters:
-
X The MPI to check for primality. This must point to an initialized MPI. rounds The number of bases to perform the Miller-Rabin primality test for. The probability of returning 0 on a composite is at most 2-2* rounds
.f_rng The RNG function to use. This must not be NULL
.p_rng The RNG parameter to be passed to f_rng
. This may beNULL
iff_rng
doesn't use a context parameter.
- Returns:
0
if successful, i.e.X
is probably prime.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if
X
is not prime. - Another negative error code on other kinds of failure.
size_t mbedtls_mpi_lsb | ( | const mbedtls_mpi * | X ) |
Return the number of bits of value 0
before the least significant bit of value 1
.
- Note:
- This is the same as the zero-based index of the least significant bit of value
1
.
- Parameters:
-
X The MPI to query.
- Returns:
- The number of bits of value
0
before the least significant bit of value1
inX
.
int mbedtls_mpi_lset | ( | mbedtls_mpi * | X, |
mbedtls_mpi_sint | z | ||
) |
int mbedtls_mpi_mod_int | ( | mbedtls_mpi_uint * | r, |
const mbedtls_mpi * | A, | ||
mbedtls_mpi_sint | b | ||
) |
Perform a modular reduction with respect to an integer.
r = A mod b
- Parameters:
-
r The address at which to store the residue. This must not be NULL
.A The MPI to compute the residue of. This must point to an initialized MPi. b The integer base of the modular reduction.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if
b
equals zero. -
MBEDTLS_ERR_MPI_NEGATIVE_VALUE if
b
is negative. - Another negative error code on different kinds of failure.
int mbedtls_mpi_mod_mpi | ( | mbedtls_mpi * | R, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform a modular reduction.
R = A mod B
- Parameters:
-
R The destination MPI for the residue value. This must point to an initialized MPI. A The MPI to compute the residue of. This must point to an initialized MPI. B The base of the modular reduction. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
-
MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if
B
equals zero. -
MBEDTLS_ERR_MPI_NEGATIVE_VALUE if
B
is negative. - Another negative error code on different kinds of failure.
int mbedtls_mpi_mul_int | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
mbedtls_mpi_uint | b | ||
) |
Perform a multiplication of an MPI with an unsigned integer: X = A * b.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The first factor. This must point to an initialized MPI. b The second factor.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_mul_mpi | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform a multiplication of two MPIs: X = A * B.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The first factor. This must point to an initialized MPI. B The second factor. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_read_binary | ( | mbedtls_mpi * | X, |
const unsigned char * | buf, | ||
size_t | buflen | ||
) |
Import an MPI from unsigned big endian binary data.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. buf The input buffer. This must be a readable buffer of length buflen
Bytes.buflen The length of the input buffer p
in Bytes.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_read_binary_le | ( | mbedtls_mpi * | X, |
const unsigned char * | buf, | ||
size_t | buflen | ||
) |
Import X from unsigned binary data, little endian.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. buf The input buffer. This must be a readable buffer of length buflen
Bytes.buflen The length of the input buffer p
in Bytes.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_read_file | ( | mbedtls_mpi * | X, |
int | radix, | ||
FILE * | fin | ||
) |
Read an MPI from a line in an opened file.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. radix The numeric base of the string representation used in the source line. fin The input file handle to use. This must not be NULL
.
- Note:
- On success, this function advances the file stream to the end of the current line or to EOF.
The function returns 0
on an empty line.
Leading whitespaces are ignored, as is a '0x' prefix for radix 16
.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if the file read buffer is too small.
- Another negative error code on failure.
int mbedtls_mpi_read_string | ( | mbedtls_mpi * | X, |
int | radix, | ||
const char * | s | ||
) |
int mbedtls_mpi_safe_cond_assign | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | Y, | ||
unsigned char | assign | ||
) |
Perform a safe conditional copy of MPI which doesn't reveal whether the condition was true or not.
- Parameters:
-
X The MPI to conditionally assign to. This must point to an initialized MPI. Y The MPI to be assigned from. This must point to an initialized MPI. assign The condition deciding whether to perform the assignment or not. Possible values: * 1
: Perform the assignment `X = Y`. *0
: Keep the original value ofX
.
- 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).
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on other kinds of failure.
int mbedtls_mpi_safe_cond_swap | ( | mbedtls_mpi * | X, |
mbedtls_mpi * | Y, | ||
unsigned char | assign | ||
) |
Perform a safe conditional swap which doesn't reveal whether the condition was true or not.
- Parameters:
-
X The first MPI. This must be initialized. Y The second MPI. This must be initialized. assign The condition deciding whether to perform the swap or not. Possible values: * 1
: Swap the values ofX
andY
. *0
: Keep the original values ofX
andY
.
- 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).
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on other kinds of failure.
int mbedtls_mpi_self_test | ( | int | verbose ) |
int mbedtls_mpi_set_bit | ( | mbedtls_mpi * | X, |
size_t | pos, | ||
unsigned char | val | ||
) |
Modify a specific bit in an MPI.
- Note:
- This function will grow the target MPI if necessary to set a bit to
1
in a not yet existing limb. It will not grow if the bit should be set to0
.
- Parameters:
-
X The MPI to modify. This must be initialized. pos Zero-based index of the bit to modify. val The desired value of bit pos:
0
or1
.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
- Another negative error code on other kinds of failure.
int mbedtls_mpi_shift_l | ( | mbedtls_mpi * | X, |
size_t | count | ||
) |
Perform a left-shift on an MPI: X <<= count.
- Parameters:
-
X The MPI to shift. This must point to an initialized MPI. count The number of bits to shift by.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_shift_r | ( | mbedtls_mpi * | X, |
size_t | count | ||
) |
Perform a right-shift on an MPI: X >>= count.
- Parameters:
-
X The MPI to shift. This must point to an initialized MPI. count The number of bits to shift by.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_shrink | ( | mbedtls_mpi * | X, |
size_t | nblimbs | ||
) |
This function resizes an MPI downwards, keeping at least the specified number of limbs.
If X
is smaller than nblimbs
, it is resized up instead.
- Parameters:
-
X The MPI to shrink. This must point to an initialized MPI. nblimbs The minimum number of limbs to keep.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed (this can only happen when resizing up).
- Another negative error code on other kinds of failure.
size_t mbedtls_mpi_size | ( | const mbedtls_mpi * | X ) |
Return the total size of an MPI value in bytes.
- Parameters:
-
X The MPI to use. This must point to an initialized MPI.
- Note:
- The value returned by this function may be less than the number of bytes used to store
X
internally. This happens if and only if there are trailing bytes of value zero.
- Returns:
- The least number of bytes capable of storing the absolute value of
X
.
int mbedtls_mpi_sub_abs | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform an unsigned subtraction of MPIs: X = |A| - |B|.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The minuend. This must point to an initialized MPI. B The subtrahend. This must point to an initialized MPI.
- Returns:
0
if successful.-
MBEDTLS_ERR_MPI_NEGATIVE_VALUE if
B
is greater thanA
. - Another negative error code on different kinds of failure.
int mbedtls_mpi_sub_int | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
mbedtls_mpi_sint | b | ||
) |
Perform a signed subtraction of an MPI and an integer: X = A - b.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The minuend. This must point to an initialized MPI. b The subtrahend.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
int mbedtls_mpi_sub_mpi | ( | mbedtls_mpi * | X, |
const mbedtls_mpi * | A, | ||
const mbedtls_mpi * | B | ||
) |
Perform a signed subtraction of MPIs: X = A - B.
- Parameters:
-
X The destination MPI. This must point to an initialized MPI. A The minuend. This must point to an initialized MPI. B The subtrahend. This must point to an initialized MPI.
- Returns:
0
if successful.- MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- Another negative error code on different kinds of failure.
void mbedtls_mpi_swap | ( | mbedtls_mpi * | X, |
mbedtls_mpi * | Y | ||
) |
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 The source MPI. This must point to an initialized MPI. buf The output buffer. This must be a writable buffer of length buflen
Bytes.buflen The size of the output buffer buf
in Bytes.
- Returns:
0
if successful.-
MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if
buf
isn't large enough to hold the value ofX
. - Another negative error code on different kinds of failure.
int mbedtls_mpi_write_binary_le | ( | const mbedtls_mpi * | X, |
unsigned char * | buf, | ||
size_t | buflen | ||
) |
Export X into unsigned binary data, little endian.
Always fills the whole buffer, which will end with zeros if the number is smaller.
- Parameters:
-
X The source MPI. This must point to an initialized MPI. buf The output buffer. This must be a writable buffer of length buflen
Bytes.buflen The size of the output buffer buf
in Bytes.
- Returns:
0
if successful.-
MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if
buf
isn't large enough to hold the value ofX
. - Another negative error code on different kinds of failure.
int mbedtls_mpi_write_file | ( | const char * | p, |
const mbedtls_mpi * | X, | ||
int | radix, | ||
FILE * | fout | ||
) |
Export an MPI into an opened file.
- Parameters:
-
p A string prefix to emit prior to the MPI data. For example, this might be a label, or "0x" when printing in base 16
. This may beNULL
if no prefix is needed.X The source MPI. This must point to an initialized MPI. radix The numeric base to be used in the emitted string. fout The output file handle. This may be NULL
, in which case the output is written tostdout
.
- Returns:
0
if successful.- A negative error code on failure.
int mbedtls_mpi_write_string | ( | const mbedtls_mpi * | X, |
int | radix, | ||
char * | buf, | ||
size_t | buflen, | ||
size_t * | olen | ||
) |
Export an MPI to an ASCII string.
- Parameters:
-
X The source MPI. This must point to an initialized MPI. radix The numeric base of the output string. buf The buffer to write the string to. This must be writable buffer of length buflen
Bytes.buflen The available size in Bytes of buf
.olen The address at which to store the length of the string written, including the final NULL
byte. This must not beNULL
.
- Note:
- You can call this function with `buflen == 0` to obtain the minimum required buffer size in `*olen`.
- Returns:
0
if successful.-
MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if the target buffer
buf
is too small to hold the value ofX
in the desired base. In this case, `*olen` is nonetheless updated to contain the size ofbuf
required for a successful call. - Another negative error code on different kinds of failure.
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