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Diffstat (limited to 'openssl/doc/crypto/BN_generate_prime.pod')
| -rw-r--r-- | openssl/doc/crypto/BN_generate_prime.pod | 90 |
1 files changed, 69 insertions, 21 deletions
diff --git a/openssl/doc/crypto/BN_generate_prime.pod b/openssl/doc/crypto/BN_generate_prime.pod index 7dccacbc1..bf1b5308a 100644 --- a/openssl/doc/crypto/BN_generate_prime.pod +++ b/openssl/doc/crypto/BN_generate_prime.pod @@ -2,12 +2,31 @@ =head1 NAME -BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - generate primes and test for primality +BN_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 =head1 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); @@ -20,27 +39,27 @@ BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - generate primes and test =head1 DESCRIPTION -BN_generate_prime() generates a pseudo-random prime number of B<num> -bits. +BN_generate_prime_ex() generates a pseudo-random prime number of +bit length B<bits>. If B<ret> is not B<NULL>, it will be used to store the number. -If B<callback> is not B<NULL>, it is called as follows: +If B<cb> is not B<NULL>, it is used as follows: =over 4 =item * -B<callback(0, i, cb_arg)> is called after generating the i-th +B<BN_GENCB_call(cb, 0, i)> is called after generating the i-th potential prime number. =item * -While the number is being tested for primality, B<callback(1, j, -cb_arg)> is called as described below. +While the number is being tested for primality, +B<BN_GENCB_call(cb, 1, j)> is called as described below. =item * -When a prime has been found, B<callback(2, i, cb_arg)> is called. +When a prime has been found, B<BN_GENCB_call(cb, 2, i)> is called. =back @@ -54,38 +73,67 @@ generator. If B<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 BN_generate_prime(). +The PRNG must be seeded prior to calling BN_generate_prime_ex(). The prime number generation has a negligible error probability. -BN_is_prime() and BN_is_prime_fasttest() test if the number B<a> is +BN_is_prime_ex() and BN_is_prime_fasttest_ex() test if the number B<p> is prime. The following tests are performed until one of them shows that -B<a> is composite; if B<a> passes all these tests, it is considered +B<p> is composite; if B<p> passes all these tests, it is considered prime. -BN_is_prime_fasttest(), when called with B<do_trial_division == 1>, +BN_is_prime_fasttest_ex(), when called with B<do_trial_division == 1>, first attempts trial division by a number of small primes; -if no divisors are found by this test and B<callback> is not B<NULL>, -B<callback(1, -1, cb_arg)> is called. +if no divisors are found by this test and B<cb> is not B<NULL>, +B<BN_GENCB_call(cb, 1, -1)> is called. If B<do_trial_division == 0>, this test is skipped. -Both BN_is_prime() and BN_is_prime_fasttest() perform a Miller-Rabin -probabilistic primality test with B<checks> iterations. If -B<checks == BN_prime_checks>, a number of iterations is used that +Both BN_is_prime_ex() and BN_is_prime_fasttest_ex() perform a Miller-Rabin +probabilistic primality test with B<nchecks> iterations. If +B<nchecks == BN_prime_checks>, a number of iterations is used that yields a false positive rate of at most 2^-80 for random input. -If B<callback> is not B<NULL>, B<callback(1, j, cb_arg)> is called +If B<cb> is not B<NULL>, B<BN_GENCB_call(cb, 1, j)> is called after the j-th iteration (j = 0, 1, ...). B<ctx> is a pre-allocated B<BN_CTX> (to save the overhead of allocating and freeing the structure in a loop), or B<NULL>. +BN_GENCB_call calls the callback function held in the B<BN_GENCB> structure +and passes the ints B<a> and B<b> as arguments. There are two types of +B<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 BN_GENCB_set, where B<gencb> is a B<BN_GENCB *>, B<callback> is of +type B<int (*callback)(int, int, BN_GENCB *)> and B<cb_arg> is a B<void *>. +"Old" style callbacks are the same except they are initialised with a call +to BN_GENCB_set_old and B<callback> is of type +B<void (*callback)(int, int, void *)>. + +A callback is invoked through a call to B<BN_GENCB_call>. This will check +the type of the callback and will invoke B<callback(a, b, gencb)> for new +style callbacks or B<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 B<callback> parameter, and an argument to pass to it in +the B<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. + =head1 RETURN VALUES -BN_generate_prime() returns the prime number on success, B<NULL> otherwise. +BN_generate_prime_ex() return 1 on success or 0 on error. -BN_is_prime() returns 0 if the number is composite, 1 if it is -prime with an error probability of less than 0.25^B<checks>, and +BN_is_prime_ex(), BN_is_prime_fasttest_ex(), BN_is_prime() and +BN_is_prime_fasttest() return 0 if the number is composite, 1 if it is +prime with an error probability of less than 0.25^B<nchecks>, and -1 on error. +BN_generate_prime() returns the prime number on success, B<NULL> otherwise. + +Callback functions should return 1 on success or 0 on error. + The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>. =head1 SEE ALSO |