RSA_GENERATE_KEY(3)        Library Functions Manual        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 rsa.

     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(3) function:

     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 VALUES
     RSA_generate_key_ex() returns 1 on success or 0 on error.
     RSA_generate_key() returns the key on success or NULL on error.

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

SEE ALSO
     BN_generate_prime(3), RSA_get0_key(3), RSA_meth_set_keygen(3), RSA_new(3)

HISTORY
     RSA_generate_key() appeared in SSLeay 0.4 or earlier and had its cb_arg
     argument added in SSLeay 0.9.0.  It has been available since OpenBSD 2.4.

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

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.

Linux 6.8.7-arch1-1              June 10, 2019             Linux 6.8.7-arch1-1