RSAgeneratekey(3) OpenSSL RSAgeneratekey(3)

NAME
       RSAgeneratekey - generate RSA key pair

SYNOPSIS
        #include 

        RSA *RSAgeneratekey(int num, unsigned long e,
           void (*callback)(int,int,void *), void *cbarg);

DESCRIPTION
       RSAgeneratekey() generates a key pair and returns it in a newly
       allocated RRSSAA structure. The pseudo-random number generator must be
       seeded prior to calling RSAgeneratekey().

       The modulus size will be nnuumm bits, and the public exponent will be ee.
       Key sizes with nnuumm < 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 ccaallllbbaacckk is not NNUULLLL, it will be called as
       follows:

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

       +o   When the n-th randomly generated prime is rejected as not suitable
           for the key, ccaallllbbaacckk((22,, nn,, ccbbaarrgg)) is called.

       +o   When a random p has been found with p-1 relatively prime to ee, it
           is called as ccaallllbbaacckk((33,, 00,, ccbbaarrgg)).

       The process is then repeated for prime q with ccaallllbbaacckk((33,, 11,, ccbbaarrgg)).

RREETTUURRNN VVAALLUUEE
       If key generation fails, RSAgeneratekey() returns NNUULLLL; the error
       codes can be obtained by ERRgeterror(3).

BUGS
       ccaallllbbaacckk((22,, xx,, ccbbaarrgg)) is used with two different meanings.

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

SEE ALSO
       ERRgeterror(3), rand(3), rsa(3), RSAfree(3)

HISTORY       The ccbbaarrgg argument was added in SSLeay 0.9.0.



0.9.7l                            2002-09-25               RSAgeneratekey(3)