diff options
Diffstat (limited to 'genrsa.c')
| -rw-r--r-- | genrsa.c | 34 |
1 files changed, 15 insertions, 19 deletions
@@ -34,7 +34,7 @@ #ifdef DROPBEAR_RSA static void getrsaprime(mp_int* prime, mp_int *primeminus, - mp_int* rsa_e, unsigned int size); + mp_int* rsa_e, unsigned int size_bytes); /* mostly taken from libtomcrypt's rsa key generation routine */ dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) { @@ -44,26 +44,22 @@ dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) { DEF_MP_INT(qminus); DEF_MP_INT(lcm); - key = m_malloc(sizeof(*key)); - - key->e = (mp_int*)m_malloc(sizeof(mp_int)); - key->n = (mp_int*)m_malloc(sizeof(mp_int)); - key->d = (mp_int*)m_malloc(sizeof(mp_int)); - key->p = (mp_int*)m_malloc(sizeof(mp_int)); - key->q = (mp_int*)m_malloc(sizeof(mp_int)); - - m_mp_init_multi(key->e, key->n, key->d, key->p, key->q, - &pminus, &lcm, &qminus, NULL); + if (size < 512 || size > 4096 || (size % 8 != 0)) { + dropbear_exit("Bits must satisfy 512 <= bits <= 4096, and be a" + " multiple of 8"); + } - seedrandom(); + key = m_malloc(sizeof(*key)); + m_mp_alloc_init_multi(&key->e, &key->n, &key->d, &key->p, &key->q, NULL); + m_mp_init_multi(&pminus, &lcm, &qminus, NULL); if (mp_set_int(key->e, RSA_E) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } - getrsaprime(key->p, &pminus, key->e, size/2); - getrsaprime(key->q, &qminus, key->e, size/2); + getrsaprime(key->p, &pminus, key->e, size/16); + getrsaprime(key->q, &qminus, key->e, size/16); if (mp_mul(key->p, key->q, key->n) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); @@ -90,21 +86,21 @@ dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) { /* return a prime suitable for p or q */ static void getrsaprime(mp_int* prime, mp_int *primeminus, - mp_int* rsa_e, unsigned int size) { + mp_int* rsa_e, unsigned int size_bytes) { unsigned char *buf; DEF_MP_INT(temp_gcd); - buf = (unsigned char*)m_malloc(size+1); + buf = (unsigned char*)m_malloc(size_bytes+1); m_mp_init(&temp_gcd); do { /* generate a random odd number with MSB set, then find the the next prime above it */ - genrandom(buf, size+1); + genrandom(buf, size_bytes+1); buf[0] |= 0x80; /* MSB set */ - bytes_to_mp(prime, buf, size+1); + bytes_to_mp(prime, buf, size_bytes+1); /* find the next integer which is prime, 8 round of miller-rabin */ if (mp_prime_next_prime(prime, 8, 0) != MP_OKAY) { @@ -126,7 +122,7 @@ static void getrsaprime(mp_int* prime, mp_int *primeminus, /* now we have a good value for result */ mp_clear(&temp_gcd); - m_burn(buf, size+1); + m_burn(buf, size_bytes+1); m_free(buf); } |