BN_bn2binpad, BN_bn2bin, BN_bin2bn, BN_bn2lebinpad, BN_lebin2bn,
BN_bn2nativepad, BN_native2bn, BN_bn2hex, BN_bn2dec, BN_hex2bn, BN_dec2bn,
BN_print, BN_print_fp, BN_bn2mpi, BN_mpi2bn - format conversions
#include <openssl/bn.h>
int BN_bn2bin(const BIGNUM *a, unsigned char *to);
int BN_bn2binpad(const BIGNUM *a, unsigned char *to, int tolen);
BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret);
int BN_bn2lebinpad(const BIGNUM *a, unsigned char *to, int tolen);
BIGNUM *BN_lebin2bn(const unsigned char *s, int len, BIGNUM *ret);
int BN_bn2nativepad(const BIGNUM *a, unsigned char *to, int tolen);
BIGNUM *BN_native2bn(const unsigned char *s, int len, BIGNUM *ret);
char *BN_bn2hex(const BIGNUM *a);
char *BN_bn2dec(const BIGNUM *a);
int BN_hex2bn(BIGNUM **a, const char *str);
int BN_dec2bn(BIGNUM **a, const char *str);
int BN_print(BIO *fp, const BIGNUM *a);
int BN_print_fp(FILE *fp, const BIGNUM *a);
int BN_bn2mpi(const BIGNUM *a, unsigned char *to);
BIGNUM *BN_mpi2bn(unsigned char *s, int len, BIGNUM *ret);
BN_bn2bin() converts the absolute value of
a into big-endian form
and stores it at
to.
to must point to BN_num_bytes(
a)
bytes of memory.
BN_bn2binpad() also converts the absolute value of
a into
big-endian form and stores it at
to.
tolen indicates the length
of the output buffer
to. The result is padded with zeros if necessary.
If
tolen is less than BN_num_bytes(
a) an error is returned.
BN_bin2bn() converts the positive integer in big-endian form of length
len at
s into a
BIGNUM and places it in
ret. If
ret is NULL, a new
BIGNUM is created.
BN_bn2lebinpad() and
BN_lebin2bn() are identical to
BN_bn2binpad() and
BN_bin2bn() except the buffer is in
little-endian format.
BN_bn2nativepad() and
BN_native2bn() are identical to
BN_bn2binpad() and
BN_bin2bn() except the buffer is in native
format, i.e. most significant byte first on big-endian platforms, and least
significant byte first on little-endian platforms.
BN_bn2hex() and
BN_bn2dec() return printable strings containing
the hexadecimal and decimal encoding of
a respectively. For negative
numbers, the string is prefaced with a leading '-'. The string must be freed
later using
OPENSSL_free().
BN_hex2bn() takes as many characters as possible from the string
str, including the leading character '-' which means negative, to form
a valid hexadecimal number representation and converts them to a
BIGNUM
and stores it in **
a. If *
a is NULL, a new
BIGNUM is
created. If
a is NULL, it only computes the length of valid
representation. A "negative zero" is converted to zero.
BN_dec2bn() is the same using the decimal system.
BN_print() and
BN_print_fp() write the hexadecimal encoding of
a, with a leading '-' for negative numbers, to the
BIO or
FILE fp.
BN_bn2mpi() and
BN_mpi2bn() convert
BIGNUMs from and to a
format that consists of the number's length in bytes represented as a 4-byte
big-endian number, and the number itself in big-endian format, where the most
significant bit signals a negative number (the representation of numbers with
the MSB set is prefixed with null byte).
BN_bn2mpi() stores the representation of
a at
to, where
to must be large enough to hold the result. The size can be determined
by calling BN_bn2mpi(
a, NULL).
BN_mpi2bn() converts the
len bytes long representation at
s
to a
BIGNUM and stores it at
ret, or in a newly allocated
BIGNUM if
ret is NULL.
BN_bn2bin() returns the length of the big-endian number placed at
to.
BN_bin2bn() returns the
BIGNUM, NULL on error.
BN_bn2binpad(),
BN_bn2lebinpad(), and
BN_bn2nativepad()
return the number of bytes written or -1 if the supplied buffer is too small.
BN_bn2hex() and
BN_bn2dec() return a NUL-terminated string, or
NULL on error.
BN_hex2bn() and
BN_dec2bn() return the number of
characters used in parsing, or 0 on error, in which case no new
BIGNUM
will be created.
BN_print_fp() and
BN_print() return 1 on success, 0 on write
errors.
BN_bn2mpi() returns the length of the representation.
BN_mpi2bn()
returns the
BIGNUM, and NULL on error.
The error codes can be obtained by
ERR_get_error(3).
ERR_get_error(3),
BN_zero(3),
ASN1_INTEGER_to_BN(3),
BN_num_bytes(3)
Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at
<
https://www.openssl.org/source/license.html>.