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DSA_generate_parameters_exgenerate DSA parameters

#include <openssl/dsa.h>

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);

() generates primes p and q and a generator g for use in the DSA and stores the result in dsa.

bits is the length of the prime to be generated; the DSS allows a maximum of 1024 bits.

If seed is NULL or seed_len < 20, the primes will be generated at random. Otherwise, the seed is used to generate them. If the given seed does not yield a prime q, a new random seed is chosen and placed at seed.

() places the iteration count in *counter_ret and a counter used for finding a generator in *h_ret, 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, refer to BN_GENCB_call(3).

DSA_generate_parameters_ex() returns a 1 on success, or 0 otherwise.

The error codes can be obtained by ERR_get_error(3).

BN_generate_prime(3), DSA_get0_pqg(3), DSA_new(3)

DSA_generate_parameters_ex() first appeared in OpenSSL 0.9.8 and has been available since OpenBSD 4.5.

Seed lengths > 20 are not supported.

December 29, 2023 OpenBSD-current