| =pod |
| |
| =head1 NAME |
| |
| BN_bn2binpad, BN_signed_bn2bin, BN_bn2bin, BN_bin2bn, BN_signed_bin2bn, |
| BN_bn2lebinpad, BN_signed_bn2lebin, BN_lebin2bn, BN_signed_lebin2bn, |
| BN_bn2nativepad, BN_signed_bn2native, BN_native2bn, BN_signed_native2bn, |
| 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); |
| int BN_bn2binpad(const BIGNUM *a, unsigned char *to, int tolen); |
| int BN_signed_bn2bin(const BIGNUM *a, unsigned char *to, int tolen); |
| BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret); |
| BIGNUM *BN_signed_bin2bn(const unsigned char *s, int len, BIGNUM *ret); |
| |
| int BN_bn2lebinpad(const BIGNUM *a, unsigned char *to, int tolen); |
| int BN_signed_bn2lebin(const BIGNUM *a, unsigned char *to, int tolen); |
| BIGNUM *BN_lebin2bn(const unsigned char *s, int len, BIGNUM *ret); |
| BIGNUM *BN_signed_lebin2bn(const unsigned char *s, int len, BIGNUM *ret); |
| |
| int BN_bn2nativepad(const BIGNUM *a, unsigned char *to, int tolen); |
| int BN_signed_bn2native(const BIGNUM *a, unsigned char *to, int tolen); |
| BIGNUM *BN_native2bn(const unsigned char *s, int len, BIGNUM *ret); |
| BIGNUM *BN_signed_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); |
| |
| =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_bn2binpad() also converts the absolute value of B<a> into big-endian form |
| and stores it at B<to>. B<tolen> indicates the length of the output buffer |
| B<to>. The result is padded with zeros if necessary. If B<tolen> is less than |
| BN_num_bytes(B<a>) an error is returned. |
| |
| BN_signed_bn2bin() converts the value of B<a> into big-endian signed 2's |
| complements form and stores it at B<to>. B<tolen> indicates the length of |
| the output buffer B<to>. The result is signed extended (padded with 0x00 |
| for positive numbers or with 0xff for negative numbers) if necessary. |
| If B<tolen> is smaller than the necessary size (which may be |
| C<<BN_num_bytes(B<a>) + 1>>), an error is returned. |
| |
| 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_signed_bin2bn() converts the integer in big-endian signed 2's complement |
| 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_bn2lebinpad(), BN_signed_bn2lebin() and BN_lebin2bn() are identical to |
| BN_bn2binpad(), BN_signed_bn2bin() and BN_bin2bn() except the buffer is in |
| little-endian format. |
| |
| BN_bn2nativepad(), BN_signed_bn2native() and BN_native2bn() are identical |
| to BN_bn2binpad(), BN_signed_bn2bin() 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 B<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 B<str>, |
| including the leading character '-' which means negative, to form a valid |
| hexadecimal number representation and converts them to a B<BIGNUM> and |
| stores it in **B<a>. If *B<a> is NULL, a new B<BIGNUM> is created. If |
| B<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 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_bn2binpad(), BN_signed_bn2bin(), BN_bn2lebinpad(), BN_signed_bn2lebin(), |
| BN_bn2nativepad(), and_signed BN_bn2native() 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 B<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 B<BIGNUM>, and NULL on error. |
| |
| The error codes can be obtained by L<ERR_get_error(3)>. |
| |
| =head1 SEE ALSO |
| |
| L<ERR_get_error(3)>, L<BN_zero(3)>, |
| L<ASN1_INTEGER_to_BN(3)>, |
| L<BN_num_bytes(3)> |
| |
| =head1 COPYRIGHT |
| |
| Copyright 2000-2022 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 |
| L<https://www.openssl.org/source/license.html>. |
| |
| =cut |