DSA_generate_parameters_ex, DSA_generate_parameters - generate DSA parameters
int DSA_generate_parameters_ex(DSA *dsa, int bits,
const unsigned char *seed, int seed_len,
int *counter_ret, unsigned long *h_ret, BN_GENCB *cb);
#if OPENSSL_API_COMPAT < 0x00908000L
DSA *DSA_generate_parameters(int bits, unsigned char *seed,
int seed_len, int *counter_ret, unsigned long *h_ret,
void (*callback)(int, int, void *), void *cb_arg);
generates primes p and q and a generator g
for use in the DSA and stores the result in dsa
is the length of the prime p to be generated. For lengths under 2048
bits, the length of q is 160 bits; for lengths greater than or equal to 2048
bits, the length of q is set to 256 bits.
is NULL, the primes will be generated at random. If
is less than the length of q, an error is returned.
places the iteration count in *
and a counter used for finding a generator in *
, unless these are NULL
A callback function may be used to provide feedback about the progress of the
key generation. If cb
is not NULL
, it will be called as shown
below. For information on the BN_GENCB structure and the BN_GENCB_call
function discussed below, refer to BN_generate_prime
- When a candidate for q is generated, BN_GENCB_call(cb,
0, m++) is called (m is 0 for the first candidate).
- When a candidate for q has passed a test by trial division,
BN_GENCB_call(cb, 1, -1) is called. While a candidate for q is
tested by Miller-Rabin primality tests, BN_GENCB_call(cb, 1, i) is
called in the outer loop (once for each witness that confirms that the
candidate may be prime); i is the loop counter (starting at 0).
- When a prime q has been found, BN_GENCB_call(cb, 2,
0) and BN_GENCB_call(cb, 3, 0) are called.
- Before a candidate for p (other than the first) is
generated and tested, BN_GENCB_call(cb, 0, counter) is called.
- When a candidate for p has passed the test by trial
division, BN_GENCB_call(cb, 1, -1) is called. While it is tested by
the Miller-Rabin primality test, BN_GENCB_call(cb, 1, i) is called
in the outer loop (once for each witness that confirms that the candidate
may be prime). i is the loop counter (starting at 0).
- When p has been found, BN_GENCB_call(cb, 2, 1) is
- When the generator has been found, BN_GENCB_call(cb, 3,
1) is called.
(deprecated) works in much the same way as for
DSA_generate_parameters_ex, except that no dsa
parameter is passed and
instead a newly allocated DSA
structure is returned. Additionally
"old style" callbacks are used instead of the newer BN_GENCB based
approach. Refer to BN_generate_prime
(3) for further information.
returns a 1 on success, or 0 otherwise.
returns a pointer to the DSA structure, or
if the parameter generation fails.
The error codes can be obtained by ERR_get_error
Seed lengths > 20 are not supported.
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Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at