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BN_generate_prime(3)
NAMEBN_generate_prime_ex, BN_is_prime_ex, BN_is_prime_fasttest_ex, BN_GENCB_call, BN_GENCB_set_old, BN_GENCB_set, BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - generate primes and test for primality
SYNOPSIS#include <openssl/bn.h> int BN_generate_prime_ex(BIGNUM *ret,int bits,int safe, const BIGNUM *add, const BIGNUM *rem, BN_GENCB *cb); int BN_is_prime_ex(const BIGNUM *p,int nchecks, BN_CTX *ctx, BN_GENCB *cb); int BN_is_prime_fasttest_ex(const BIGNUM *p,int nchecks, BN_CTX *ctx, int do_trial_division, BN_GENCB *cb); int BN_GENCB_call(BN_GENCB *cb, int a, int b); #define BN_GENCB_set_old(gencb, callback, cb_arg) ... #define BN_GENCB_set(gencb, callback, cb_arg) ... Deprecated: BIGNUM *BN_generate_prime(BIGNUM *ret, int num, int safe, BIGNUM *add, BIGNUM *rem, void (*callback)(int, int, void *), void *cb_arg); int BN_is_prime(const BIGNUM *a, int checks, void (*callback)(int, int, void *), BN_CTX *ctx, void *cb_arg); int BN_is_prime_fasttest(const BIGNUM *a, int checks, void (*callback)(int, int, void *), BN_CTX *ctx, void *cb_arg, int do_trial_division);
DESCRIPTION
If cb is not NULL, it is used as follows:
The prime may have to fulfill additional requirements for use in Diffie-Hellman key exchange: If add is not NULL, the prime will fulfill the condition p % add == rem (p % add == 1 if rem == NULL) in order to suit a given generator. If safe is true, it will be a safe prime (i.e. a prime p so that (p-1)/2 is also prime).
The PRNG must be seeded prior to calling
Both If cb is not NULL, BN_GENCB_call(cb, 1, j) is called after the j-th iteration (j = 0, 1, ...). ctx is a pre-allocated BN_CTX (to save the overhead of allocating and freeing the structure in a loop), or NULL. BN_GENCB_call calls the callback function held in the BN_GENCB structure and passes the ints a and b as arguments. There are two types of BN_GENCB structure that are supported: ``new'' style and ``old'' style. New programs should prefer the ``new'' style, whilst the ``old'' style is provided for backwards compatibility purposes.
For ``new'' style callbacks a BN_GENCB structure should be initialised with
a call to A callback is invoked through a call to BN_GENCB_call. This will check the type of the callback and will invoke callback(a, b, gencb) for new style callbacks or callback(a, b, cb_arg) for old style. BN_generate_prime (deprecated) works in the same way as BN_generate_prime_ex but expects an old style callback function directly in the callback parameter, and an argument to pass to it in the cb_arg. Similarly BN_is_prime and BN_is_prime_fasttest are deprecated and can be compared to BN_is_prime_ex and BN_is_prime_fasttest_ex respectively.
RETURN VALUES
Callback functions should return 1 on success or 0 on error. The error codes can be obtained by ERR_get_error(3).
SEE ALSObn(3), ERR_get_error(3), rand(3)
HISTORY
The cb_arg arguments to | ||||||||||||||||||||