/usr/man/cat.3/RSA_generate_key.3

RSA_generate_key(3)          OpenSSL          RSA_generate_key(3)

NAME

     RSA_generate_key_ex, RSA_generate_key - generate RSA key
     pair

SYNOPSIS

      #include <openssl/rsa.h>

      int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);

     Deprecated:

      RSA *RSA_generate_key(int num, unsigned long e,
         void (*callback)(int,int,void *), void *cb_arg);

DESCRIPTION

     RSA_generate_key_ex() generates a key pair and stores it in
     the RSA structure provided in rsa. The pseudo-random number
     generator must be seeded prior to calling
     RSA_generate_key_ex().

     The modulus size will be of length bits, and the public
     exponent will be e. Key sizes with num < 1024 should be
     considered insecure.  The exponent is an odd number,
     typically 3, 17 or 65537.

     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 follows using the BN_GENCB_call() function
     described on the BN_generate_prime(3) page.

     o   While a random prime number is generated, it is called
         as described in BN_generate_prime(3).

     o   When the n-th randomly generated prime is rejected as
         not suitable for the key, BN_GENCB_call(cb, 2, n) is
         called.

     o   When a random p has been found with p-1 relatively prime
         to e, it is called as BN_GENCB_call(cb, 3, 0).

     The process is then repeated for prime q with
     BN_GENCB_call(cb, 3, 1).

     RSA_generate_key is deprecated (new applications should use
     RSA_generate_key_ex instead). RSA_generate_key works in the
     same way as RSA_generate_key_ex except it uses "old style"
     call backs. See BN_generate_prime(3) for further details.

RETURN VALUE

     If key generation fails, RSA_generate_key() returns NULL.

1.0.2t               Last change: 2019-09-10                    1

RSA_generate_key(3)          OpenSSL          RSA_generate_key(3)

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

BUGS

     BN_GENCB_call(cb, 2, x) is used with two different meanings.

     RSA_generate_key() goes into an infinite loop for illegal
     input values.

SEE ALSO

     ERR_get_error(3), rand(3), rsa(3), RSA_free(3),
     BN_generate_prime(3)

HISTORY

     The cb_arg argument was added in SSLeay 0.9.0.

1.0.2t               Last change: 2019-09-10                    2

See also RSA_generate_key_ex(3)