"Fossies" - the Fresh Open Source Software Archive

Member "libressl-2.9.2/man/BN_bn2bin.3" (2 Jan 2019, 7234 Bytes) of package /linux/misc/libressl-2.9.2.tar.gz:

Caution: As a special service "Fossies" has tried to format the requested manual source page into HTML format but links to other man pages may be missing or even errorneous. Alternatively you can here view or download the uninterpreted manual source code. A member file download can also be achieved by clicking within a package contents listing on the according byte size field. See also the last Fossies "Diffs" side-by-side code changes report for "BN_bn2bin.3": 2.9.0_vs_2.9.1.

BN_BN2BIN(3) BSD Library Functions Manual BN_BN2BIN(3)


BN_bn2bin, BN_bin2bn, BN_bn2hex, BN_bn2dec, BN_hex2bn, BN_dec2bn, BN_asc2bn, BN_print, BN_print_fp, BN_bn2mpi, BN_mpi2bn — format conversions


#include <openssl/bn.h>


BN_bn2bin(const BIGNUM *a, unsigned char *to);


BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret);

char *

BN_bn2hex(const BIGNUM *a);

char *

BN_bn2dec(const BIGNUM *a);


BN_hex2bn(BIGNUM **a, const char *str);


BN_dec2bn(BIGNUM **a, const char *str);


BN_asc2bn(BIGNUM **a, const char *str);


BN_print(BIO *fp, const BIGNUM *a);


BN_print_fp(FILE *fp, const BIGNUM *a);


BN_bn2mpi(const BIGNUM *a, unsigned char *to);


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_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_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 minus sign. The string must be freed later using free(3).

BN_hex2bn() interprets str as a hexadecimal number. The string may start with a minus sign (‘-’). Conversion stops at the first byte that is not a hexadecimal digit. The number is converted to a BIGNUM and stored in *a. If *a is NULL, a new BIGNUM is created. If a is NULL, it only computes the number’s length in hexadecimal digits, also counting the leading minus sign if there is one. A "negative zero" is converted to zero. BN_dec2bn() is the same using the decimal system. BN_asc2bn() infers the number base from an optional prefix. If str starts with "0x" or "0X", it calls BN_hex2bn(), otherwise BN_dec2bn(). If the number is negative, the minus sign can be given before or after the prefix.

BN_print() and BN_print_fp() write the hexadecimal encoding of a, with a leading minus sign 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 a NUL 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, or NULL on error.

BN_bn2hex() and BN_bn2dec() return a NUL-terminated string, or NULL on error. BN_hex2bn() and BN_dec2bn() return the number’s length in hexadecimal or decimal digits, also counting the leading minus sign if there is one, or 0 on error, in which case no new BIGNUM is created. BN_asc2bn() returns 1 on success or 0 on error, in which case no new BIGNUM is 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, or NULL on error.

The error codes can be obtained by ERR_get_error(3).


BN_new(3), BN_num_bytes(3), BN_zero(3), ERR_get_error(3)


BN_bn2bin(), BN_bin2bn(), and BN_print() first appeared in SSLeay 0.5.1. BN_print_fp() first appeared in SSLeay 0.6.0. BN_bn2hex(), BN_bn2dec(), BN_hex2bn(), BN_dec2bn(), BN_bn2mpi(), and BN_mpi2bn() first appeared in SSLeay 0.9.0. All these functions have been available since OpenBSD 2.4.

BN_asc2bin() first appeared in OpenSSL 1.0.0 and has been available since OpenBSD 4.9.

BSD December 19, 2018 BSD