1*e71b7053SJung-uk Kim=pod 2*e71b7053SJung-uk Kim 3*e71b7053SJung-uk Kim=head1 NAME 4*e71b7053SJung-uk Kim 5*e71b7053SJung-uk KimRSA_generate_key_ex, RSA_generate_key, 6*e71b7053SJung-uk KimRSA_generate_multi_prime_key - generate RSA key pair 7*e71b7053SJung-uk Kim 8*e71b7053SJung-uk Kim=head1 SYNOPSIS 9*e71b7053SJung-uk Kim 10*e71b7053SJung-uk Kim #include <openssl/rsa.h> 11*e71b7053SJung-uk Kim 12*e71b7053SJung-uk Kim int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb); 13*e71b7053SJung-uk Kim int RSA_generate_multi_prime_key(RSA *rsa, int bits, int primes, BIGNUM *e, BN_GENCB *cb); 14*e71b7053SJung-uk Kim 15*e71b7053SJung-uk KimDeprecated: 16*e71b7053SJung-uk Kim 17*e71b7053SJung-uk Kim #if OPENSSL_API_COMPAT < 0x00908000L 18*e71b7053SJung-uk Kim RSA *RSA_generate_key(int num, unsigned long e, 19*e71b7053SJung-uk Kim void (*callback)(int, int, void *), void *cb_arg); 20*e71b7053SJung-uk Kim #endif 21*e71b7053SJung-uk Kim 22*e71b7053SJung-uk Kim=head1 DESCRIPTION 23*e71b7053SJung-uk Kim 24*e71b7053SJung-uk KimRSA_generate_key_ex() generates a 2-prime RSA key pair and stores it in the 25*e71b7053SJung-uk KimB<RSA> structure provided in B<rsa>. The pseudo-random number generator must 26*e71b7053SJung-uk Kimbe seeded prior to calling RSA_generate_key_ex(). 27*e71b7053SJung-uk Kim 28*e71b7053SJung-uk KimRSA_generate_multi_prime_key() generates a multi-prime RSA key pair and stores 29*e71b7053SJung-uk Kimit in the B<RSA> structure provided in B<rsa>. The number of primes is given by 30*e71b7053SJung-uk Kimthe B<primes> parameter. The pseudo-random number generator must be seeded prior 31*e71b7053SJung-uk Kimto calling RSA_generate_multi_prime_key(). 32*e71b7053SJung-uk Kim 33*e71b7053SJung-uk KimThe modulus size will be of length B<bits>, the number of primes to form the 34*e71b7053SJung-uk Kimmodulus will be B<primes>, and the public exponent will be B<e>. Key sizes 35*e71b7053SJung-uk Kimwith B<num> E<lt> 1024 should be considered insecure. The exponent is an odd 36*e71b7053SJung-uk Kimnumber, typically 3, 17 or 65537. 37*e71b7053SJung-uk Kim 38*e71b7053SJung-uk KimIn order to maintain adequate security level, the maximum number of permitted 39*e71b7053SJung-uk KimB<primes> depends on modulus bit length: 40*e71b7053SJung-uk Kim 41*e71b7053SJung-uk Kim <1024 | >=1024 | >=4096 | >=8192 42*e71b7053SJung-uk Kim ------+--------+--------+------- 43*e71b7053SJung-uk Kim 2 | 3 | 4 | 5 44*e71b7053SJung-uk Kim 45*e71b7053SJung-uk KimA callback function may be used to provide feedback about the 46*e71b7053SJung-uk Kimprogress of the key generation. If B<cb> is not B<NULL>, it 47*e71b7053SJung-uk Kimwill be called as follows using the BN_GENCB_call() function 48*e71b7053SJung-uk Kimdescribed on the L<BN_generate_prime(3)> page. 49*e71b7053SJung-uk Kim 50*e71b7053SJung-uk KimRSA_generate_prime() is similar to RSA_generate_prime_ex() but 51*e71b7053SJung-uk Kimexpects an old-style callback function; see 52*e71b7053SJung-uk KimL<BN_generate_prime(3)> for information on the old-style callback. 53*e71b7053SJung-uk Kim 54*e71b7053SJung-uk Kim=over 2 55*e71b7053SJung-uk Kim 56*e71b7053SJung-uk Kim=item * 57*e71b7053SJung-uk Kim 58*e71b7053SJung-uk KimWhile a random prime number is generated, it is called as 59*e71b7053SJung-uk Kimdescribed in L<BN_generate_prime(3)>. 60*e71b7053SJung-uk Kim 61*e71b7053SJung-uk Kim=item * 62*e71b7053SJung-uk Kim 63*e71b7053SJung-uk KimWhen the n-th randomly generated prime is rejected as not 64*e71b7053SJung-uk Kimsuitable for the key, B<BN_GENCB_call(cb, 2, n)> is called. 65*e71b7053SJung-uk Kim 66*e71b7053SJung-uk Kim=item * 67*e71b7053SJung-uk Kim 68*e71b7053SJung-uk KimWhen a random p has been found with p-1 relatively prime to B<e>, 69*e71b7053SJung-uk Kimit is called as B<BN_GENCB_call(cb, 3, 0)>. 70*e71b7053SJung-uk Kim 71*e71b7053SJung-uk Kim=back 72*e71b7053SJung-uk Kim 73*e71b7053SJung-uk KimThe process is then repeated for prime q and other primes (if any) 74*e71b7053SJung-uk Kimwith B<BN_GENCB_call(cb, 3, i)> where B<i> indicates the i-th prime. 75*e71b7053SJung-uk Kim 76*e71b7053SJung-uk Kim=head1 RETURN VALUES 77*e71b7053SJung-uk Kim 78*e71b7053SJung-uk KimRSA_generate_multi_prime_key() returns 1 on success or 0 on error. 79*e71b7053SJung-uk KimRSA_generate_key_ex() returns 1 on success or 0 on error. 80*e71b7053SJung-uk KimThe error codes can be obtained by L<ERR_get_error(3)>. 81*e71b7053SJung-uk Kim 82*e71b7053SJung-uk KimRSA_generate_key() returns a pointer to the RSA structure or 83*e71b7053SJung-uk KimB<NULL> if the key generation fails. 84*e71b7053SJung-uk Kim 85*e71b7053SJung-uk Kim=head1 BUGS 86*e71b7053SJung-uk Kim 87*e71b7053SJung-uk KimB<BN_GENCB_call(cb, 2, x)> is used with two different meanings. 88*e71b7053SJung-uk Kim 89*e71b7053SJung-uk Kim=head1 SEE ALSO 90*e71b7053SJung-uk Kim 91*e71b7053SJung-uk KimL<ERR_get_error(3)>, L<RAND_bytes(3)>, L<BN_generate_prime(3)> 92*e71b7053SJung-uk Kim 93*e71b7053SJung-uk Kim=head1 HISTORY 94*e71b7053SJung-uk Kim 95*e71b7053SJung-uk KimRSA_generate_key() was deprecated in OpenSSL 0.9.8; use 96*e71b7053SJung-uk KimRSA_generate_key_ex() instead. 97*e71b7053SJung-uk Kim 98*e71b7053SJung-uk Kim=head1 COPYRIGHT 99*e71b7053SJung-uk Kim 100*e71b7053SJung-uk KimCopyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved. 101*e71b7053SJung-uk Kim 102*e71b7053SJung-uk KimLicensed under the OpenSSL license (the "License"). You may not use 103*e71b7053SJung-uk Kimthis file except in compliance with the License. You can obtain a copy 104*e71b7053SJung-uk Kimin the file LICENSE in the source distribution or at 105*e71b7053SJung-uk KimL<https://www.openssl.org/source/license.html>. 106*e71b7053SJung-uk Kim 107*e71b7053SJung-uk Kim=cut 108