/usr/man/cat.3/BN_mpi2bn.3(/usr/man/cat.3/BN_mpi2bn.3)

BN_bn2bin(3)                 OpenSSL                 BN_bn2bin(3)

NAME

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

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);

DESCRIPTION

     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 '-'. The string must be freed later using
     OPENSSL_free().

     BN_hex2bn() converts the string str containing a hexadecimal
     number 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
     number's length in hexadecimal digits. If the string starts
     with '-', the number is negative.  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

1.0.2t               Last change: 2019-09-10                    1

BN_bn2bin(3)                 OpenSSL                 BN_bn2bin(3)

     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.

RETURN VALUES

     BN_bn2bin() returns the length of the big-endian number
     placed at to.  BN_bin2bn() returns the 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 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).

SEE ALSO

     bn(3), ERR_get_error(3), BN_zero(3), ASN1_INTEGER_to_BN(3),
     BN_num_bytes(3)

HISTORY

     BN_bn2bin(), BN_bin2bn(), BN_print_fp() and BN_print() are
     available in all versions of SSLeay and OpenSSL.

     BN_bn2hex(), BN_bn2dec(), BN_hex2bn(), BN_dec2bn(),
     BN_bn2mpi() and BN_mpi2bn() were added in SSLeay 0.9.0.

1.0.2t               Last change: 2019-09-10                    2

See also BN_bin2bn(3)
See also BN_bn2bin(3)
See also BN_bn2dec(3)
See also BN_bn2hex(3)
See also BN_bn2mpi(3)
See also BN_dec2bn(3)
See also BN_hex2bn(3)
See also BN_print(3)
See also BN_print_fp(3)