OpenSSL BN_add(3openssl)
NNNNAAAAMMMMEEEEBN_add, BN_sub, BN_mul, BN_sqr, BN_div, BN_mod, BN_nnmod,
BN_mod_add, BN_mod_sub, BN_mod_mul, BN_mod_sqr, BN_exp,
BN_mod_exp, BN_gcd - arithmetic operations on BIGNUMs
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS#include
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_sqr(BIGNUM *r, BIGNUM *a, BN_CTX *ctx);
int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *a, const BIGNUM *d,
BN_CTX *ctx);
int BN_mod(BIGNUM *rem, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);
int BN_nnmod(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);
int BN_mod_add(BIGNUM *r, BIGNUM *a, BIGNUM *b, const BIGNUM *m,
BN_CTX *ctx);
int BN_mod_sub(BIGNUM *r, BIGNUM *a, BIGNUM *b, const BIGNUM *m,
BN_CTX *ctx);
int BN_mod_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, const BIGNUM *m,
BN_CTX *ctx);
int BN_mod_sqr(BIGNUM *r, BIGNUM *a, 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);
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNNBN_add() adds a and b and places the result in r (r=a+b). r
may be the same BBBBIIIIGGGGNNNNUUUUMMMM as a or b.BN_sub() subtracts b from a and places the result in r
(r=a-b).
BN_mul() multiplies a and b and places the result in r
(r=a*b). r may be the same BBBBIIIIGGGGNNNNUUUUMMMM as a or b. Formultiplication by powers of 2, use BN_lshift(3).
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OpenSSL BN_add(3openssl)
BN_sqr() takes the square of a and places the result in r
(r=a^2). r and a may be the same BBBBIIIIGGGGNNNNUUUUMMMM. This function isfaster than BN_mul(r,a,a).
BN_div() 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 NNNNUUUULLLLLLLL, in which case the respective value is not returned. The result is rounded towards zero; thus if a is negative, the remainder will be zero or negative. For division bypowers of 2, use BN_rshift(3).
BN_mod() corresponds to BN_div() with dv set to NNNNUUUULLLLLLLL.
BN_nnmod() reduces a modulo m and places the non-negative
remainder in r.BN_mod_add() adds a to b modulo m and places the non-
negative result in r.BN_mod_sub() subtracts b from a modulo m and places the
non-negative result in r.
BN_mod_mul() multiplies a by b and finds the non-negative
remainder respective to modulus m (r=(a*b) mod m). r may be the same BBBBIIIIGGGGNNNNUUUUMMMM as a or b. For more efficient algorithms for repeated computations using the same modulus, seeBN_mod_mul_montgomery(3) and BN_mod_mul_reciprocal(3).
BN_mod_sqr() takes the square of a modulo mmmm and places the
result in r.BN_exp() raises a to the p-th power and places the result in
r (r=a^p). This function is faster than repeatedapplications of BN_mul().
BN_mod_exp() computes a to the p-th 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. r may be the same BBBBIIIIGGGGNNNNUUUUMMMM as a or b.For all functions, ctx is a previously allocated BBBBNNNN_CCCCTTTTXXXX used
for temporary variables; see BN_CTX_new(3).
Unless noted otherwise, the result BBBBIIIIGGGGNNNNUUUUMMMM must be different from the arguments. RRRREEEETTTTUUUURRRRNNNN VVVVAAAALLLLUUUUEEEESSSS 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 ERR_get_error(3).
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OpenSSL BN_add(3openssl)
SSSSEEEEEEEE AAAALLLLSSSSOOOObn(3), ERR_get_error(3), BN_CTX_new(3), BN_add_word(3),
BN_set_bit(3)
HHHHIIIISSSSTTTTOOOORRRRYYYYBN_add(), BN_sub(), BN_sqr(), BN_div(), 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. BN_exp() appeared in SSLeay
0.9.0. BN_nnmod(), BN_mod_add(), BN_mod_sub(), and
BN_mod_sqr() were added in OpenSSL 0.9.7.
25/Sep/2002 Last change: 0.9.8o 3