Index for Section 3

Alphabetical listing for B

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BN_add(3)
NAME
  BN_add, BN_sub, BN_mul, BN_div, BN_sqr, BN_mod, BN_mod_mul, BN_exp,
  BN_mod_exp, BN_gcd - Arithmetic operations on BIGNUMs

SYNOPSIS
  #include <openssl/bn.h>

  int BN_add(
	  BIGNUM *r, const BIGNUM *a, const BIGNUM *b );

  int BN_sub(
	  BIGNUM *r, const BIGNUM *a, const BIGNUM *b );

  int BN_mul(
	  BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx );

  int BN_div(
	  BIGNUM *dv, BIGNUM *rem, const BIGNUM *a, const BIGNUM *d,
  BN_CTX *ctx );

  int BN_sqr(
	  BIGNUM *r, BIGNUM *a, BN_CTX *ctx );

  int BN_mod(
	  BIGNUM *rem, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx );

  int BN_mod_mul(
	  BIGNUM *ret, BIGNUM *a, BIGNUM *b, const BIGNUM *m, BN_CTX *ctx );

  int BN_exp(
	  BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx );

  int BN_mod_exp(
	  BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx
  );

  int BN_gcd(
	  BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx );

DESCRIPTION
  The BN_add() function adds a and b and places the result in r (r=a+b). The
  r value can be the same BIGNUM as a or b.

  The BN_sub() function subtracts b from a and places the result in r (r=a-
  b).

  The BN_mul() function multiplies a and b and places the result in r
  (r=a*b). The r value may be the same BIGNUM as a or b. For multiplication
  by powers of 2, use the BN_lshift() function.

  The BN_div() function divides a by d and places the result in dv and the
  remainder in rem (dv=a/d, rem=a%d).  Either of dv and rem may be NULL, in
  which case the respective value is not returned. For division by powers of
  2, use the BN_rshift() function.

  The BN_sqr() function takes the square of a and places the result in r
  (r=a^2). The r and a values may be the same BIGNUM. This function is faster
  than BN_mul(r,a,a).

  The BN_mod() function finds the remainder of a divided by m and places it
  in rem (rem=a%m).

  The BN_mod_mul() function multiplies a by b and finds the remainder when
  divided by m (r=(a*b)%m). The r value may be the same BIGNUM as a or b. For
  a more efficient algorithm, see BN_mod_mul_montgomery(3); for repeated
  computations using the same modulus, see BN_mod_mul_reciprocal(3).

  The BN_exp() function raises a to the p power and places the result in r
  (r=a^p). This function is faster than repeated applications of BN_mul().

  BN_mod_exp() computes a to the p power modulo m (r=a^p % m).	This function
  uses less time and space than BN_exp().

  BN_gcd() computes the greatest common divisor of a and b and places the
  result in r.	The r value may be the same BIGNUM as a or b.

  For all functions, ctx is a previously allocated BN_CTX used for temporary
  variables. See BN_CTX_new(3).

  Unless noted otherwise, the result BIGNUM must be different from the
  arguments.

RETURN VALUES
  For all functions, 1 is returned for success, 0 on error. The return value
  should always be checked (e.g., if (!BN_add(r,a,b)) goto err;). The error
  codes can be obtained by using the ERR_get_error() function.

HISTORY
  The BN_add(), BN_sub(), BN_div(), BN_sqr(), BN_mod(), BN_mod_mul(),
  BN_mod_exp(), and BN_gcd() are available in all versions of SSLeay and
  OpenSSL. The ctx argument to BN_mul() was added in SSLeay 0.9.1b. The
  BN_exp() function appeared in SSLeay 0.9.0.

SEE ALSO
  Functions: bn(3), err(3), BN_CTX_new(3), BN_add_word(3), BN_set_bit(3)

Index for Section 3

Alphabetical listing for B

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