a528d4f0a9
If something was "present in all versions" of SSLeay, or if it was added to a version of SSLeay (and therefore predates OpenSSL), remove mention of it. Documentation history now starts with OpenSSL. Remove mention of all history before OpenSSL 0.9.8, inclusive. Remove all AUTHOR sections. Reviewed-by: Tim Hudson <tjh@openssl.org>
87 lines
3 KiB
Text
87 lines
3 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
BN_bn2bin, BN_bin2bn, BN_bn2hex, BN_bn2dec, BN_hex2bn, BN_dec2bn,
|
|
BN_print, BN_print_fp, BN_bn2mpi, BN_mpi2bn - format conversions
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/bn.h>
|
|
|
|
int BN_bn2bin(const BIGNUM *a, unsigned char *to);
|
|
BIGNUM *BN_bin2bn(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);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
BN_bn2bin() converts the absolute value of B<a> into big-endian form
|
|
and stores it at B<to>. B<to> must point to BN_num_bytes(B<a>) bytes of
|
|
memory.
|
|
|
|
BN_bin2bn() converts the positive integer in big-endian form of length
|
|
B<len> at B<s> into a B<BIGNUM> and places it in B<ret>. If B<ret> is
|
|
NULL, a new B<BIGNUM> is created.
|
|
|
|
BN_bn2hex() and BN_bn2dec() return printable strings containing the
|
|
hexadecimal and decimal encoding of B<a> respectively. For negative
|
|
numbers, the string is prefaced with a leading '-'. The string must be
|
|
freed later using OPENSSL_free().
|
|
|
|
BN_hex2bn() converts the string B<str> containing a hexadecimal number
|
|
to a B<BIGNUM> and stores it in **B<bn>. If *B<bn> is NULL, a new
|
|
B<BIGNUM> is created. If B<bn> is NULL, it only computes the number's
|
|
length in hexadecimal digits. If the string starts with '-', the
|
|
number is negative. BN_dec2bn() is the same using the decimal system.
|
|
|
|
BN_print() and BN_print_fp() write the hexadecimal encoding of B<a>,
|
|
with a leading '-' for negative numbers, to the B<BIO> or B<FILE>
|
|
B<fp>.
|
|
|
|
BN_bn2mpi() and BN_mpi2bn() convert B<BIGNUM>s 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 B<a> at B<to>, where B<to>
|
|
must be large enough to hold the result. The size can be determined by
|
|
calling BN_bn2mpi(B<a>, NULL).
|
|
|
|
BN_mpi2bn() converts the B<len> bytes long representation at B<s> to
|
|
a B<BIGNUM> and stores it at B<ret>, or in a newly allocated B<BIGNUM>
|
|
if B<ret> is NULL.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
BN_bn2bin() returns the length of the big-endian number placed at B<to>.
|
|
BN_bin2bn() returns the B<BIGNUM>, NULL on error.
|
|
|
|
BN_bn2hex() and BN_bn2dec() return a null-terminated string, or NULL
|
|
on error. BN_hex2bn() and BN_dec2bn() return the number's length in
|
|
hexadecimal or decimal digits, and 0 on error.
|
|
|
|
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 B<BIGNUM>, and NULL on error.
|
|
|
|
The error codes can be obtained by L<ERR_get_error(3)>.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<bn(3)>, L<ERR_get_error(3)>, L<BN_zero(3)>,
|
|
L<ASN1_INTEGER_to_BN(3)>,
|
|
L<BN_num_bytes(3)>
|
|
|
|
=cut
|