denozord/strongswan-ext
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

implemented generation of safe primes

Browse Source
This commit is contained in:
Andreas Steffen
2012-11-18 19:22:31 +01:00
parent c1c98f5f4a
commit 168ee460c6
4 changed files with 60 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libstrongswan/plugins/gmp/gmp_rsa_private_key.c
+37 -13
View File
@@ -132,10 +132,10 @@ static void mpz_clear_sensitive(mpz_t z)
/**
* Create a mpz prime of at least prime_size
*/
static status_t compute_prime(private_gmp_rsa_private_key_t *this,
size_t prime_size, mpz_t *prime)
static status_t compute_prime(size_t prime_size, bool safe, mpz_t *prime)
{
rng_t *rng;
mpz_t q;
chunk_t random_bytes;
rng = lib->crypto->create_rng(lib->crypto, RNG_TRUE);
@@ -147,6 +147,8 @@ static status_t compute_prime(private_gmp_rsa_private_key_t *this,
}
mpz_init(*prime);
mpz_init(q);
do
{
if (!rng->allocate_bytes(rng, prime_size, &random_bytes))
@@ -155,17 +157,36 @@ static status_t compute_prime(private_gmp_rsa_private_key_t *this,
rng->destroy(rng);
return FAILED;
}
/* make sure the two most significant bits are set */
random_bytes.ptr[0] = random_bytes.ptr[0] | 0xC0;
mpz_import(*prime, random_bytes.len, 1, 1, 1, 0, random_bytes.ptr);
mpz_nextprime (*prime, *prime);
/* make sure the two most significant bits are set */
if (safe)
{
random_bytes.ptr[0] &= 0x7F;
random_bytes.ptr[0] |= 0x60;
mpz_import(q, random_bytes.len, 1, 1, 1, 0, random_bytes.ptr);
do
{
mpz_nextprime (q, q);
mpz_mul_ui(*prime, q, 2);
mpz_add_ui(*prime, *prime, 1);
}
while (mpz_probab_prime_p(*prime, 10) == 0);
}
else
{
random_bytes.ptr[0] |= 0xC0;
mpz_import(*prime, random_bytes.len, 1, 1, 1, 0, random_bytes.ptr);
mpz_nextprime (*prime, *prime);
}
chunk_clear(&random_bytes);
}
/* check if it isn't too large */
/* check if the prime isn't too large */
while (((mpz_sizeinbase(*prime, 2) + 7) / 8) > prime_size);
rng->destroy(rng);
mpz_clear(q);
return SUCCESS;
}
@@ -600,6 +621,7 @@ gmp_rsa_private_key_t *gmp_rsa_private_key_gen(key_type_t type, va_list args)
mpz_t p, q, n, e, d, exp1, exp2, coeff, m, q1, t;
private_gmp_rsa_private_key_t *this;
u_int key_size = 0;
bool safe_prime = FALSE;
while (TRUE)
{
@@ -608,6 +630,9 @@ gmp_rsa_private_key_t *gmp_rsa_private_key_gen(key_type_t type, va_list args)
case BUILD_KEY_SIZE:
key_size = va_arg(args, u_int);
continue;
case BUILD_SAFE_PRIMES:
safe_prime = TRUE;
continue;
case BUILD_END:
break;
default:
@@ -620,19 +645,16 @@ gmp_rsa_private_key_t *gmp_rsa_private_key_gen(key_type_t type, va_list args)
return NULL;
}
this = gmp_rsa_private_key_create_empty();
key_size = key_size / BITS_PER_BYTE;
/* Get values of primes p and q */
if (compute_prime(this, key_size/2, &p) != SUCCESS)
if (compute_prime(key_size/2, safe_prime, &p) != SUCCESS)
{
free(this);
return NULL;
}
if (compute_prime(this, key_size/2, &q) != SUCCESS)
if (compute_prime(key_size/2, safe_prime, &q) != SUCCESS)
{
mpz_clear(p);
free(this);
return NULL;
}
@@ -651,7 +673,7 @@ gmp_rsa_private_key_t *gmp_rsa_private_key_gen(key_type_t type, va_list args)
mpz_mul(n, p, q); /* n = p*q */
mpz_init_set_ui(e, PUBLIC_EXPONENT); /* assign public exponent */
mpz_init_set(m, p); /* m = p */
mpz_init_set(m, p); /* m = p */
mpz_sub_ui(m, m, 1); /* m = m -1 */
mpz_init_set(q1, q); /* q1 = q */
mpz_sub_ui(q1, q1, 1); /* q1 = q1 -1 */
@@ -680,6 +702,8 @@ gmp_rsa_private_key_t *gmp_rsa_private_key_gen(key_type_t type, va_list args)
mpz_clear_sensitive(m);
mpz_clear_sensitive(t);
this = gmp_rsa_private_key_create_empty();
/* apply values */
*(this->p) = *p;
*(this->q) = *q;