Index for Section 3

Alphabetical listing for B

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BN_set_bit(3)
NAME
  BN_set_bit, BN_clear_bit, BN_is_bit_set, BN_mask_bits, BN_lshift,
  BN_lshift1, BN_rshift, BN_rshift1 - Bit operations on BIGNUMs

SYNOPSIS
  #include <openssl/bn.h>

  int BN_set_bit(
	  BIGNUM *a, int n );

  int BN_clear_bit(
	  BIGNUM *a, int n );

  int BN_is_bit_set(
	  const BIGNUM *a, int n );

  int BN_mask_bits(
	  BIGNUM *a, int n );

  int BN_lshift(
	  BIGNUM *r, const BIGNUM *a, int n );

  int BN_lshift1(
	  BIGNUM *r, BIGNUM *a );

  int BN_rshift(
	  BIGNUM *r, BIGNUM *a, int n );

  int BN_rshift1(
	  BIGNUM *r, BIGNUM *a );

DESCRIPTION
  The BN_set_bit() function sets bit n in a to 1 (a|=(1<<n)). The number is
  expanded if necessary.

  The BN_clear_bit() function sets bit n in a to 0 (a&=~(1<<n)). An error
  occurs if a is shorter than n bits.

  The BN_is_bit_set() function tests if bit n in a is set.

  The BN_mask_bits() function truncates a to an n bit number (a&=~((~0)>>n)).
  An error occurs if a already is shorter than n bits.

  The BN_lshift() function shifts a left by n bits and places the result in r
  (r=a*2^n). The BN_lshift1() function shifts a left by one and places the
  result in r (r=2*a).

  The BN_rshift() function shifts a right by n bits and places the result in
  r (r=a/2^n). The BN_rshift1() function shifts a right by one and places the
  result in r (r=a/2).

  For the shift functions, r and a may be the same variable.

RETURN VALUES
  The BN_is_bit_set() function returns 1 if the bit is set, 0 otherwise.

  All other functions return 1 for success, 0 on error. The error codes can
  be obtained by using ERR_get_error().

HISTORY
  The BN_set_bit(), BN_clear_bit(), BN_is_bit_set(), BN_mask_bits(),
  BN_lshift(), BN_lshift1(), BN_rshift(), and BN_rshift1() functions are
  available in all versions of SSLeay and OpenSSL.

SEE ALSO
  Functions: bn(3), BN_num_bytes(3), BN_add(3)

Index for Section 3

Alphabetical listing for B

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