Mercurial > dropbear
view libtomcrypt/src/pk/rsa/rsa_make_key.c @ 1772:0cc85b4a4abb
Move fuzzer-kex initialisation into a constructor function
Hopefully this can avoid hitting AFL timeouts
https://github.com/google/oss-fuzz/pull/2474
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 29 Oct 2020 23:00:52 +0800 |
parents | 6dba84798cd5 |
children |
line wrap: on
line source
/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. */ #include "tomcrypt.h" /** @file rsa_make_key.c RSA key generation, Tom St Denis */ #ifdef LTC_MRSA /** Create an RSA key @param prng An active PRNG state @param wprng The index of the PRNG desired @param size The size of the modulus (key size) desired (octets) @param e The "e" value (public key). e==65537 is a good choice @param key [out] Destination of a newly created private key pair @return CRYPT_OK if successful, upon error all allocated ram is freed */ int rsa_make_key(prng_state *prng, int wprng, int size, long e, rsa_key *key) { void *p, *q, *tmp1, *tmp2, *tmp3; int err; LTC_ARGCHK(ltc_mp.name != NULL); LTC_ARGCHK(key != NULL); LTC_ARGCHK(size > 0); if ((e < 3) || ((e & 1) == 0)) { return CRYPT_INVALID_ARG; } if ((err = prng_is_valid(wprng)) != CRYPT_OK) { return err; } if ((err = mp_init_multi(&p, &q, &tmp1, &tmp2, &tmp3, NULL)) != CRYPT_OK) { return err; } /* make primes p and q (optimization provided by Wayne Scott) */ if ((err = mp_set_int(tmp3, e)) != CRYPT_OK) { goto cleanup; } /* tmp3 = e */ /* make prime "p" */ do { if ((err = rand_prime( p, size/2, prng, wprng)) != CRYPT_OK) { goto cleanup; } if ((err = mp_sub_d( p, 1, tmp1)) != CRYPT_OK) { goto cleanup; } /* tmp1 = p-1 */ if ((err = mp_gcd( tmp1, tmp3, tmp2)) != CRYPT_OK) { goto cleanup; } /* tmp2 = gcd(p-1, e) */ } while (mp_cmp_d( tmp2, 1) != 0); /* while e divides p-1 */ /* make prime "q" */ do { if ((err = rand_prime( q, size/2, prng, wprng)) != CRYPT_OK) { goto cleanup; } if ((err = mp_sub_d( q, 1, tmp1)) != CRYPT_OK) { goto cleanup; } /* tmp1 = q-1 */ if ((err = mp_gcd( tmp1, tmp3, tmp2)) != CRYPT_OK) { goto cleanup; } /* tmp2 = gcd(q-1, e) */ } while (mp_cmp_d( tmp2, 1) != 0); /* while e divides q-1 */ /* tmp1 = lcm(p-1, q-1) */ if ((err = mp_sub_d( p, 1, tmp2)) != CRYPT_OK) { goto cleanup; } /* tmp2 = p-1 */ /* tmp1 = q-1 (previous do/while loop) */ if ((err = mp_lcm( tmp1, tmp2, tmp1)) != CRYPT_OK) { goto cleanup; } /* tmp1 = lcm(p-1, q-1) */ /* make key */ if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ, &key->dP, &key->qP, &key->p, &key->q, NULL)) != CRYPT_OK) { goto errkey; } if ((err = mp_set_int( key->e, e)) != CRYPT_OK) { goto errkey; } /* key->e = e */ if ((err = mp_invmod( key->e, tmp1, key->d)) != CRYPT_OK) { goto errkey; } /* key->d = 1/e mod lcm(p-1,q-1) */ if ((err = mp_mul( p, q, key->N)) != CRYPT_OK) { goto errkey; } /* key->N = pq */ /* optimize for CRT now */ /* find d mod q-1 and d mod p-1 */ if ((err = mp_sub_d( p, 1, tmp1)) != CRYPT_OK) { goto errkey; } /* tmp1 = q-1 */ if ((err = mp_sub_d( q, 1, tmp2)) != CRYPT_OK) { goto errkey; } /* tmp2 = p-1 */ if ((err = mp_mod( key->d, tmp1, key->dP)) != CRYPT_OK) { goto errkey; } /* dP = d mod p-1 */ if ((err = mp_mod( key->d, tmp2, key->dQ)) != CRYPT_OK) { goto errkey; } /* dQ = d mod q-1 */ if ((err = mp_invmod( q, p, key->qP)) != CRYPT_OK) { goto errkey; } /* qP = 1/q mod p */ if ((err = mp_copy( p, key->p)) != CRYPT_OK) { goto errkey; } if ((err = mp_copy( q, key->q)) != CRYPT_OK) { goto errkey; } /* set key type (in this case it's CRT optimized) */ key->type = PK_PRIVATE; /* return ok and free temps */ err = CRYPT_OK; goto cleanup; errkey: rsa_free(key); cleanup: mp_clear_multi(tmp3, tmp2, tmp1, q, p, NULL); return err; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */