DSA_generate_parameters_ex, DSA_generate_parameters - generate DSA parameters

       Seed lengths greater than 20 are not supported.

       Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (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
       <https://www.openssl.org/source/license.html>.

3.5.0                                              2025-06-04                      DSA_GENERATE_PARAMETERS(3SSL)

       All of the functions described on this page are deprecated.  Applications should instead use
       EVP_PKEY_paramgen_init(3) and EVP_PKEY_keygen(3) as described in EVP_PKEY-DSA(7).

       DSA_generate_parameters_ex() 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 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.

       If seed is NULL, the primes will be generated at random.  If seed_len is less than the length of q, an
       error is returned.

       DSA_generate_parameters_ex() 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 and the
       BN_GENCB_call function discussed below, refer to BN_generate_prime(3).

       DSA_generate_parameters() is similar to DSA_generate_parameters_ex() but expects an old-style callback
       function; see BN_generate_prime(3) for information on the old-style callback.

       • 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 called.

       • When the generator has been found, BN_GENCB_call(cb,3,1) is called.

DSA_generate_parameters_ex() was deprecated in OpenSSL 3.0.

       DSA_generate_parameters() was deprecated in OpenSSL 0.9.8; use DSA_generate_parameters_ex() instead.

       DSA_generate_parameters_ex, DSA_generate_parameters - generate DSA parameters

DSA_generate_parameters_ex() returns a 1 on success, or 0 otherwise.  The error codes can be obtained  by
       ERR_get_error(3).

       DSA_generate_parameters()  returns  a  pointer  to  the DSA structure or NULL if the parameter generation
       fails.

DSA_new(3), ERR_get_error(3), RAND_bytes(3), DSA_free(3), BN_generate_prime(3)

        #include <openssl/dsa.h>

       The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining
       OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):

        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);

       The following functions have been deprecated since OpenSSL 0.9.8, and can be hidden entirely by defining
       OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):

        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);