=pod =head1 NAME RSA_generate_key - generate RSA key pair =head1 SYNOPSIS #include RSA *RSA_generate_key(int num, unsigned long e, void (*callback)(int,int,void *), void *cb_arg); =head1 DESCRIPTION RSA_generate_key() generates a key pair and returns it in a newly allocated B structure. The pseudo-random number generator must be seeded prior to calling RSA_generate_key(). The modulus size will be B bits, and the public exponent will be B. Key sizes with B E 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 B is not B, it will be called as follows: =over 4 =item * While a random prime number is generated, it is called as described in L. =item * When the n-th randomly generated prime is rejected as not suitable for the key, B is called. =item * When a random p has been found with p-1 relatively prime to B, it is called as B. =back The process is then repeated for prime q with B. =head1 RETURN VALUE If key generation fails, RSA_generate_key() returns B; the error codes can be obtained by L. =head1 BUGS B is used with two different meanings. RSA_generate_key() goes into an infinite loop for illegal input values. =head1 SEE ALSO L, L, L, L =head1 HISTORY The B argument was added in SSLeay 0.9.0. =cut