void jacobian_double(struct jacobian_point *p, const struct domain_params *dp)
{
if (gcry_mpi_cmp_ui(p->z, 0)) {
if (gcry_mpi_cmp_ui(p->y, 0)) {
gcry_mpi_t t1, t2;
t1 = gcry_mpi_snew(0);
t2 = gcry_mpi_snew(0);
gcry_mpi_mulm(t1, p->x, p->x, dp->m);
gcry_mpi_addm(t2, t1, t1, dp->m);
gcry_mpi_addm(t2, t2, t1, dp->m);
gcry_mpi_mulm(t1, p->z, p->z, dp->m);
gcry_mpi_mulm(t1, t1, t1, dp->m);
gcry_mpi_mulm(t1, t1, dp->a, dp->m);
gcry_mpi_addm(t1, t1, t2, dp->m);
gcry_mpi_mulm(p->z, p->z, p->y, dp->m);
gcry_mpi_addm(p->z, p->z, p->z, dp->m);
gcry_mpi_mulm(p->y, p->y, p->y, dp->m);
gcry_mpi_addm(p->y, p->y, p->y, dp->m);
gcry_mpi_mulm(t2, p->x, p->y, dp->m);
gcry_mpi_addm(t2, t2, t2, dp->m);
gcry_mpi_mulm(p->x, t1, t1, dp->m);
gcry_mpi_subm(p->x, p->x, t2, dp->m);
gcry_mpi_subm(p->x, p->x, t2, dp->m);
gcry_mpi_subm(t2, t2, p->x, dp->m);
gcry_mpi_mulm(t1, t1, t2, dp->m);
gcry_mpi_mulm(t2, p->y, p->y, dp->m);
gcry_mpi_addm(t2, t2, t2, dp->m);
gcry_mpi_subm(p->y, t1, t2, dp->m);
gcry_mpi_release(t1);
gcry_mpi_release(t2);
}
else
gcry_mpi_set_ui(p->z, 0);
}
}
int point_decompress(struct affine_point *p, const gcry_mpi_t x, int yflag,
const struct domain_params *dp)
{
gcry_mpi_t h, y;
int res;
h = gcry_mpi_snew(0);
y = gcry_mpi_snew(0);
gcry_mpi_mulm(h, x, x, dp->m);
gcry_mpi_addm(h, h, dp->a, dp->m);
gcry_mpi_mulm(h, h, x, dp->m);
gcry_mpi_addm(h, h, dp->b, dp->m);
if ((res = mod_root(y, h, dp->m)))
if ((res = (gcry_mpi_cmp_ui(y, 0) || ! yflag))) {
p->x = gcry_mpi_snew(0);
p->y = gcry_mpi_snew(0);
gcry_mpi_set(p->x, x);
if (gcry_mpi_test_bit(y, 0) == yflag)
gcry_mpi_set(p->y, y);
else
gcry_mpi_sub(p->y, dp->m, y);
assert(point_on_curve(p, dp));
}
gcry_mpi_release(h);
gcry_mpi_release(y);
return res;
}
struct affine_point point_new(void)
{
struct affine_point r;
r.x = gcry_mpi_snew(0);
r.y = gcry_mpi_snew(0);
return r;
}
struct jacobian_point jacobian_new(void)
{
struct jacobian_point r;
r.x = gcry_mpi_snew(0);
r.y = gcry_mpi_snew(0);
r.z = gcry_mpi_snew(0);
return r;
}
void point_add(struct affine_point *p1, const struct affine_point *p2,
const struct domain_params *dp)
{
if (! point_is_zero(p2)) {
if (! point_is_zero(p1)) {
if (! gcry_mpi_cmp(p1->x, p2->x)) {
if (! gcry_mpi_cmp(p1->y, p2->y))
point_double(p1, dp);
else
point_load_zero(p1);
}
else {
gcry_mpi_t t;
t = gcry_mpi_snew(0);
gcry_mpi_subm(t, p1->y, p2->y, dp->m);
gcry_mpi_subm(p1->y, p1->x, p2->x, dp->m);
gcry_mpi_invm(p1->y, p1->y, dp->m);
gcry_mpi_mulm(p1->y, t, p1->y, dp->m);
gcry_mpi_mulm(t, p1->y, p1->y, dp->m);
gcry_mpi_addm(p1->x, p1->x, p2->x, dp->m);
gcry_mpi_subm(p1->x, t, p1->x, dp->m);
gcry_mpi_subm(t, p2->x, p1->x, dp->m);
gcry_mpi_mulm(p1->y, p1->y, t, dp->m);
gcry_mpi_subm(p1->y, p1->y, p2->y, dp->m);
gcry_mpi_release(t);
}
}
else
point_set(p1, p2);
}
}
/*output this number*/
void mpiOut2(gcry_mpi_t value)
{ int i=0;
char buffer[1024/8],buffer2[1024/8]; //buffer for the output
gcry_randomize (buffer, 1024/8, GCRY_STRONG_RANDOM);
printf("\n random buffer: ");
for (i = 0; i<1024/8; i++){
if(i%32==0)
printf("\n");
printf("%0u", (unsigned char)buffer[i]);
}
printf("\n");
gcry_mpi_t test;
test=gcry_mpi_snew(1024/8);
gcry_mpi_scan(&test,GCRYMPI_FMT_STD,buffer,sizeof(buffer),NULL);
gcry_mpi_print(GCRYMPI_FMT_STD,buffer2,sizeof(buffer2),NULL,test); //converts the MPI to a writable buffer
printf("\n random buffer2:\n");
for (i = 0; i<1024/8; i++){
if(i%32==0)
printf("\n");
printf("%0u", (unsigned char)buffer2[i]);
}
printf("\n test");
}
int deserialize_mpi(gcry_mpi_t *x, enum disp_format df, const char *buf,
int inlen)
{
switch(df) {
case DF_BIN:
gcry_mpi_scan(x, GCRYMPI_FMT_USG, buf, inlen, NULL);
gcry_mpi_set_flag(*x, GCRYMPI_FLAG_SECURE);
break;
case DF_COMPACT:
case DF_BASE36:
do {
const char *digits = get_digits(df);
unsigned int digit_count = get_digit_count(df);
char *d;
int i;
*x = gcry_mpi_snew(0);
for(i = 0; i < inlen; i++) {
if (! (d = memchr(digits, buf[i], digit_count))) {
gcry_mpi_release(*x);
return 0;
}
gcry_mpi_mul_ui(*x, *x, digit_count);
gcry_mpi_add_ui(*x, *x, d - digits);
}
} while (0);
break;
default:
assert(0);
}
return 1;
}
/* Choose a random value x and calculate e = g^x mod p. Returns e and
if ret_x is not NULL x. */
static gcry_mpi_t
calc_dh_secret (gcry_mpi_t gex_g, gcry_mpi_t gex_p, gcry_mpi_t * ret_x)
{
gcry_mpi_t e, g, x, prime;
size_t n = sizeof diffie_hellman_group1_prime;
if (gex_p)
prime = gcry_mpi_copy (gex_p);
else if (gcry_mpi_scan (&prime, GCRYMPI_FMT_STD,
diffie_hellman_group1_prime, n, NULL))
abort ();
/*_gsti_dump_mpi( "prime=", prime );*/
if (gex_g)
g = gcry_mpi_copy (gex_g);
else
g = gcry_mpi_set_ui (NULL, 2);
/* FIXME: we n bits for the private exponent,
where n is 2*derrived_key_material */
x = gcry_mpi_snew (200);
gcry_mpi_randomize (x, 200, GCRY_STRONG_RANDOM);
n = gcry_mpi_get_nbits (prime);
e = gcry_mpi_new (n+1);
gcry_mpi_powm (e, g, x, prime);
if (ret_x)
*ret_x = x;
else
gcry_mpi_release (x);
gcry_mpi_release (g);
gcry_mpi_release (prime);
return e;
}
int point_on_curve(const struct affine_point *p, const struct domain_params *dp)
{
int res;
if (! (res = point_is_zero(p))) {
gcry_mpi_t h1, h2;
h1 = gcry_mpi_snew(0);
h2 = gcry_mpi_snew(0);
gcry_mpi_mulm(h1, p->x, p->x, dp->m);
gcry_mpi_addm(h1, h1, dp->a, dp->m);
gcry_mpi_mulm(h1, h1, p->x, dp->m);
gcry_mpi_addm(h1, h1, dp->b, dp->m);
gcry_mpi_mulm(h2, p->y, p->y, dp->m);
res = ! gcry_mpi_cmp(h1, h2);
gcry_mpi_release(h1);
gcry_mpi_release(h2);
}
return res;
}
/* Algorithms 4.29 and 4.30 in the "Guide to Elliptic Curve Cryptography" */
gcry_mpi_t ECDSA_sign(const char *msg, const gcry_mpi_t d,
const struct curve_params *cp)
{
struct affine_point p1;
gcry_mpi_t e, k, r, s;
#if ECDSA_DETERMINISTIC
struct aes256cprng *cprng;
cprng = ecdsa_cprng_init(msg, d, cp);
#endif
r = gcry_mpi_snew(0);
s = gcry_mpi_snew(0);
Step1:
#if ECDSA_DETERMINISTIC
k = ecdsa_cprng_get_exponent(cprng, cp);
#else
k = get_random_exponent(cp);
#endif
p1 = pointmul(&cp->dp.base, k, &cp->dp);
gcry_mpi_mod(r, p1.x, cp->dp.order);
point_release(&p1);
if (! gcry_mpi_cmp_ui(r, 0)) {
gcry_mpi_release(k);
goto Step1;
}
gcry_mpi_scan(&e, GCRYMPI_FMT_USG, msg, 64, NULL);
gcry_mpi_set_flag(e, GCRYMPI_FLAG_SECURE);
gcry_mpi_mod(e, e, cp->dp.order);
gcry_mpi_mulm(s, d, r, cp->dp.order);
gcry_mpi_addm(s, s, e, cp->dp.order);
gcry_mpi_invm(e, k, cp->dp.order);
gcry_mpi_mulm(s, s, e, cp->dp.order);
gcry_mpi_release(e);
gcry_mpi_release(k);
if (! gcry_mpi_cmp_ui(s, 0))
goto Step1;
gcry_mpi_mul(s, s, cp->dp.order);
gcry_mpi_add(s, s, r);
gcry_mpi_release(r);
#if ECDSA_DETERMINISTIC
ecdsa_cprng_done(cprng);
#endif
return s;
}
void jacobian_affine_point_add(struct jacobian_point *p1,
const struct affine_point *p2,
const struct domain_params *dp)
{
if (! point_is_zero(p2)) {
if (gcry_mpi_cmp_ui(p1->z, 0)) {
gcry_mpi_t t1, t2, t3;
t1 = gcry_mpi_snew(0);
t2 = gcry_mpi_snew(0);
gcry_mpi_mulm(t1, p1->z, p1->z, dp->m);
gcry_mpi_mulm(t2, t1, p2->x, dp->m);
gcry_mpi_mulm(t1, t1, p1->z, dp->m);
gcry_mpi_mulm(t1, t1, p2->y, dp->m);
if (! gcry_mpi_cmp(p1->x, t2)) {
if (! gcry_mpi_cmp(p1->y, t1))
jacobian_double(p1, dp);
else
jacobian_load_zero(p1);
}
else {
t3 = gcry_mpi_snew(0);
gcry_mpi_subm(p1->x, p1->x, t2, dp->m);
gcry_mpi_subm(p1->y, p1->y, t1, dp->m);
gcry_mpi_mulm(p1->z, p1->z, p1->x, dp->m);
gcry_mpi_mulm(t3, p1->x, p1->x, dp->m);
gcry_mpi_mulm(t2, t2, t3, dp->m);
gcry_mpi_mulm(t3, t3, p1->x, dp->m);
gcry_mpi_mulm(t1, t1, t3, dp->m);
gcry_mpi_mulm(p1->x, p1->y, p1->y, dp->m);
gcry_mpi_subm(p1->x, p1->x, t3, dp->m);
gcry_mpi_subm(p1->x, p1->x, t2, dp->m);
gcry_mpi_subm(p1->x, p1->x, t2, dp->m);
gcry_mpi_subm(t2, t2, p1->x, dp->m);
gcry_mpi_mulm(p1->y, p1->y, t2, dp->m);
gcry_mpi_subm(p1->y, p1->y, t1, dp->m);
gcry_mpi_release(t3);
}
gcry_mpi_release(t1);
gcry_mpi_release(t2);
}
else
jacobian_load_affine(p1, p2);
}
}
gcry_mpi_t get_random_exponent(const struct curve_params *cp)
{
int bits = gcry_mpi_get_nbits(cp->dp.order);
gcry_mpi_t a;
a = gcry_mpi_snew(0);
do {
gcry_mpi_randomize(a, bits, GCRY_STRONG_RANDOM);
gcry_mpi_clear_highbit(a, bits);
} while (! gcry_mpi_cmp_ui(a, 0) || gcry_mpi_cmp(a, cp->dp.order) >= 0);
return a;
}
GkmDataResult
gkm_data_der_read_private_key_dsa_parts (const guchar *keydata, gsize n_keydata,
const guchar *params, gsize n_params,
gcry_sexp_t *s_key)
{
gcry_mpi_t p, q, g, y, x;
GkmDataResult ret = GKM_DATA_UNRECOGNIZED;
int res;
GNode *asn_params = NULL;
GNode *asn_key = NULL;
p = q = g = y = x = NULL;
asn_params = egg_asn1x_create_and_decode (pk_asn1_tab, "DSAParameters", params, n_params);
asn_key = egg_asn1x_create_and_decode (pk_asn1_tab, "DSAPrivatePart", keydata, n_keydata);
if (!asn_params || !asn_key)
goto done;
ret = GKM_DATA_FAILURE;
if (!gkm_data_asn1_read_mpi (egg_asn1x_node (asn_params, "p", NULL), &p) ||
!gkm_data_asn1_read_mpi (egg_asn1x_node (asn_params, "q", NULL), &q) ||
!gkm_data_asn1_read_mpi (egg_asn1x_node (asn_params, "g", NULL), &g))
goto done;
if (!gkm_data_asn1_read_mpi (asn_key, &x))
goto done;
/* Now we calculate y */
y = gcry_mpi_snew (1024);
gcry_mpi_powm (y, g, x, p);
res = gcry_sexp_build (s_key, NULL, SEXP_PRIVATE_DSA, p, q, g, y, x);
if (res)
goto done;
g_assert (*s_key);
ret = GKM_DATA_SUCCESS;
done:
egg_asn1x_destroy (asn_key);
egg_asn1x_destroy (asn_params);
gcry_mpi_release (p);
gcry_mpi_release (q);
gcry_mpi_release (g);
gcry_mpi_release (y);
gcry_mpi_release (x);
if (ret == GKM_DATA_FAILURE)
g_message ("invalid DSA key");
return ret;
}
void compress_to_string(char *buf, enum disp_format df,
const struct affine_point *P,
const struct curve_params *cp)
{
int outlen = (df == DF_COMPACT) ? cp->pk_len_compact : cp->pk_len_bin;
if (point_compress(P)) {
gcry_mpi_t x;
x = gcry_mpi_snew(0);
gcry_mpi_add(x, P->x, cp->dp.m);
serialize_mpi(buf, outlen, df, x);
gcry_mpi_release(x);
}
else
serialize_mpi(buf, outlen, df, P->x);
}
struct affine_point jacobian_to_affine(const struct jacobian_point *p,
const struct domain_params *dp)
{
struct affine_point r = point_new();
if (gcry_mpi_cmp_ui(p->z, 0)) {
gcry_mpi_t h;
h = gcry_mpi_snew(0);
gcry_mpi_invm(h, p->z, dp->m);
gcry_mpi_mulm(r.y, h, h, dp->m);
gcry_mpi_mulm(r.x, p->x, r.y, dp->m);
gcry_mpi_mulm(r.y, r.y, h, dp->m);
gcry_mpi_mulm(r.y, r.y, p->y, dp->m);
gcry_mpi_release(h);
}
return r;
}
int ECIES_decryption(char *key, const struct affine_point *R,
const gcry_mpi_t d, const struct curve_params *cp)
{
struct affine_point Z;
gcry_mpi_t e;
int res = 0;
if (! embedded_key_validation(R, &cp->dp))
return 0;
e = gcry_mpi_snew(0);
gcry_mpi_mul_ui(e, d, cp->dp.cofactor);
Z = pointmul(R, e, &cp->dp);
gcry_mpi_release(e);
if ((res = ! point_is_zero(&Z)))
ECIES_KDF(key, Z.x, R, cp->elem_len_bin);
point_release(&Z);
return res;
}
gpointer
egg_dh_gen_secret (gcry_mpi_t peer, gcry_mpi_t priv,
gcry_mpi_t prime, gsize *bytes)
{
gcry_error_t gcry;
guchar *value;
gsize n_value;
gcry_mpi_t k;
gint bits;
g_return_val_if_fail (peer, NULL);
g_return_val_if_fail (priv, NULL);
g_return_val_if_fail (prime, NULL);
bits = gcry_mpi_get_nbits (prime);
g_return_val_if_fail (bits >= 0, NULL);
k = gcry_mpi_snew (bits);
g_return_val_if_fail (k, NULL);
gcry_mpi_powm (k, peer, priv, prime);
/* Write out the secret */
gcry = gcry_mpi_print (GCRYMPI_FMT_USG, NULL, 0, &n_value, k);
g_return_val_if_fail (gcry == 0, NULL);
value = egg_secure_alloc (n_value);
gcry = gcry_mpi_print (GCRYMPI_FMT_USG, value, n_value, &n_value, k);
g_return_val_if_fail (gcry == 0, NULL);
#if DEBUG_DH_SECRET
g_printerr ("DH SECRET: ");
gcry_mpi_dump (k);
gcry_mpi_release (k);
#endif
*bytes = n_value;
#if DEBUG_DH_SECRET
gcry_mpi_scan (&k, GCRYMPI_FMT_USG, value, bytes, NULL);
g_printerr ("RAW SECRET: ");
gcry_mpi_dump (k);
gcry_mpi_release (k);
#endif
return value;
}
static gcry_mpi_t
calc_dh_key (gcry_mpi_t gex_p, gcry_mpi_t f, gcry_mpi_t x)
{
gcry_mpi_t k, prime;
size_t n = sizeof diffie_hellman_group1_prime;
if (gex_p)
prime = gcry_mpi_copy (gex_p);
else if (gcry_mpi_scan (&prime, GCRYMPI_FMT_STD,
diffie_hellman_group1_prime, n, NULL))
abort ();
n = gcry_mpi_get_nbits (prime);
k = gcry_mpi_snew (n+1);
gcry_mpi_powm (k, f, x, prime);
gcry_mpi_release (prime);
return k;
}
gboolean
egg_dh_gen_pair (gcry_mpi_t prime, gcry_mpi_t base, guint bits,
gcry_mpi_t *pub, gcry_mpi_t *priv)
{
guint pbits;
g_return_val_if_fail (prime, FALSE);
g_return_val_if_fail (base, FALSE);
g_return_val_if_fail (pub, FALSE);
g_return_val_if_fail (priv, FALSE);
pbits = gcry_mpi_get_nbits (prime);
g_return_val_if_fail (pbits > 1, FALSE);
if (bits == 0) {
bits = pbits;
} else if (bits > pbits) {
g_return_val_if_reached (FALSE);
}
/*
* Generate a strong random number of bits, and not zero.
* gcry_mpi_randomize bumps up to the next byte. Since we
* need to have a value less than half of prime, we make sure
* we bump down.
*/
*priv = gcry_mpi_snew (bits);
g_return_val_if_fail (*priv, FALSE);
while (gcry_mpi_cmp_ui (*priv, 0) == 0)
gcry_mpi_randomize (*priv, bits, GCRY_STRONG_RANDOM);
/* Secret key value must be less than half of p */
if (gcry_mpi_get_nbits (*priv) > bits)
gcry_mpi_clear_highbit (*priv, bits);
if (gcry_mpi_get_nbits (*priv) > pbits - 1)
gcry_mpi_clear_highbit (*priv, pbits - 1);
g_assert (gcry_mpi_cmp (prime, *priv) > 0);
*pub = gcry_mpi_new (gcry_mpi_get_nbits (*priv));
g_return_val_if_fail (*pub, FALSE);
gcry_mpi_powm (*pub, base, *priv, prime);
return TRUE;
}
static gboolean
dsa_subject_public_key_from_private (GNode *key_asn,
const GckAttribute *ap,
const GckAttribute *aq,
const GckAttribute *ag,
const GckAttribute *ax)
{
gcry_mpi_t mp, mq, mg, mx, my;
size_t n_buffer;
gcry_error_t gcry;
unsigned char *buffer;
gcry = gcry_mpi_scan (&mp, GCRYMPI_FMT_USG, ap->value, ap->length, NULL);
g_return_val_if_fail (gcry == 0, FALSE);
gcry = gcry_mpi_scan (&mq, GCRYMPI_FMT_USG, aq->value, aq->length, NULL);
g_return_val_if_fail (gcry == 0, FALSE);
gcry = gcry_mpi_scan (&mg, GCRYMPI_FMT_USG, ag->value, ag->length, NULL);
g_return_val_if_fail (gcry == 0, FALSE);
gcry = gcry_mpi_scan (&mx, GCRYMPI_FMT_USG, ax->value, ax->length, NULL);
g_return_val_if_fail (gcry == 0, FALSE);
/* Calculate the public part from the private */
my = gcry_mpi_snew (gcry_mpi_get_nbits (mx));
g_return_val_if_fail (my, FALSE);
gcry_mpi_powm (my, mg, mx, mp);
gcry = gcry_mpi_aprint (GCRYMPI_FMT_STD, &buffer, &n_buffer, my);
g_return_val_if_fail (gcry == 0, FALSE);
egg_asn1x_take_integer_as_raw (key_asn, g_bytes_new_with_free_func (buffer, n_buffer,
gcry_free, buffer));
gcry_mpi_release (mp);
gcry_mpi_release (mq);
gcry_mpi_release (mg);
gcry_mpi_release (mx);
gcry_mpi_release (my);
return TRUE;
}
void serialize_mpi(char *outbuf, int outlen, enum disp_format df,
const gcry_mpi_t x)
{
switch(df) {
case DF_BIN: do {
int len = (gcry_mpi_get_nbits(x) + 7) / 8;
assert(len <= outlen);
memset(outbuf, 0, outlen - len);
gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*)outbuf + (outlen - len),
len, NULL, x);
} while (0);
break;
case DF_COMPACT:
case DF_BASE36: do {
const char *digits = get_digits(df);
unsigned int digit_count = get_digit_count(df);
gcry_mpi_t base, Q, R;
int i;
base = gcry_mpi_set_ui(NULL, digit_count);
Q = gcry_mpi_copy(x);
R = gcry_mpi_snew(0);
for(i = outlen - 1; i >= 0; i--) {
unsigned char digit = 0;
gcry_mpi_div(Q, R, Q, base, 0);
gcry_mpi_print(GCRYMPI_FMT_USG, &digit, 1, NULL, R);
assert(digit < digit_count);
outbuf[i] = digits[digit];
}
assert(! gcry_mpi_cmp_ui(Q, 0));
gcry_mpi_release(base);
gcry_mpi_release(Q);
gcry_mpi_release(R);
} while(0);
break;
default:
assert(0);
}
}
/* Check that the RSA secret key SKEY is valid. Swap parameters to
the libgcrypt standard. */
static gpg_error_t
rsa_key_check (struct rsa_secret_key_s *skey)
{
int err = 0;
gcry_mpi_t t = gcry_mpi_snew (0);
gcry_mpi_t t1 = gcry_mpi_snew (0);
gcry_mpi_t t2 = gcry_mpi_snew (0);
gcry_mpi_t phi = gcry_mpi_snew (0);
/* Check that n == p * q. */
gcry_mpi_mul (t, skey->p, skey->q);
if (gcry_mpi_cmp( t, skey->n) )
{
log_error ("RSA oops: n != p * q\n");
err++;
}
/* Check that p is less than q. */
if (gcry_mpi_cmp (skey->p, skey->q) > 0)
{
gcry_mpi_t tmp;
log_info ("swapping secret primes\n");
tmp = gcry_mpi_copy (skey->p);
gcry_mpi_set (skey->p, skey->q);
gcry_mpi_set (skey->q, tmp);
gcry_mpi_release (tmp);
/* Recompute u. */
gcry_mpi_invm (skey->u, skey->p, skey->q);
}
/* Check that e divides neither p-1 nor q-1. */
gcry_mpi_sub_ui (t, skey->p, 1 );
gcry_mpi_div (NULL, t, t, skey->e, 0);
if (!gcry_mpi_cmp_ui( t, 0) )
{
log_error ("RSA oops: e divides p-1\n");
err++;
}
gcry_mpi_sub_ui (t, skey->q, 1);
gcry_mpi_div (NULL, t, t, skey->e, 0);
if (!gcry_mpi_cmp_ui( t, 0))
{
log_info ("RSA oops: e divides q-1\n" );
err++;
}
/* Check that d is correct. */
gcry_mpi_sub_ui (t1, skey->p, 1);
gcry_mpi_sub_ui (t2, skey->q, 1);
gcry_mpi_mul (phi, t1, t2);
gcry_mpi_invm (t, skey->e, phi);
if (gcry_mpi_cmp (t, skey->d))
{
/* No: try universal exponent. */
gcry_mpi_gcd (t, t1, t2);
gcry_mpi_div (t, NULL, phi, t, 0);
gcry_mpi_invm (t, skey->e, t);
if (gcry_mpi_cmp (t, skey->d))
{
log_error ("RSA oops: bad secret exponent\n");
err++;
}
}
/* Check for correctness of u. */
gcry_mpi_invm (t, skey->p, skey->q);
if (gcry_mpi_cmp (t, skey->u))
{
log_info ("RSA oops: bad u parameter\n");
err++;
}
if (err)
log_info ("RSA secret key check failed\n");
gcry_mpi_release (t);
gcry_mpi_release (t1);
gcry_mpi_release (t2);
gcry_mpi_release (phi);
return err? gpg_error (GPG_ERR_BAD_SECKEY):0;
}
guchar*
gkm_data_der_write_private_key_rsa (gcry_sexp_t s_key, gsize *n_key)
{
GNode *asn = NULL;
gcry_mpi_t n, e, d, p, q, u, e1, e2, tmp;
guchar *result = NULL;
n = e = d = p = q = u = e1 = e2 = tmp = NULL;
asn = egg_asn1x_create (pk_asn1_tab, "RSAPrivateKey");
g_return_val_if_fail (asn, NULL);
if (!gkm_sexp_extract_mpi (s_key, &n, "rsa", "n", NULL) ||
!gkm_sexp_extract_mpi (s_key, &e, "rsa", "e", NULL) ||
!gkm_sexp_extract_mpi (s_key, &d, "rsa", "d", NULL) ||
!gkm_sexp_extract_mpi (s_key, &p, "rsa", "p", NULL) ||
!gkm_sexp_extract_mpi (s_key, &q, "rsa", "q", NULL) ||
!gkm_sexp_extract_mpi (s_key, &u, "rsa", "u", NULL))
goto done;
if (!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "modulus", NULL), n) ||
!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "publicExponent", NULL), e) ||
!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "privateExponent", NULL), d) ||
!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "prime1", NULL), p) ||
!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "prime2", NULL), q) ||
!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "coefficient", NULL), u))
goto done;
/* Calculate e1 and e2 */
tmp = gcry_mpi_snew (1024);
gcry_mpi_sub_ui (tmp, p, 1);
e1 = gcry_mpi_snew (1024);
gcry_mpi_mod (e1, d, tmp);
gcry_mpi_sub_ui (tmp, q, 1);
e2 = gcry_mpi_snew (1024);
gcry_mpi_mod (e2, d, tmp);
/* Write out calculated */
if (!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "exponent1", NULL), e1) ||
!gkm_data_asn1_write_mpi (egg_asn1x_node (asn, "exponent2", NULL), e2))
goto done;
/* Write out the version */
if (!egg_asn1x_set_integer_as_ulong (egg_asn1x_node (asn, "version", NULL), 0))
goto done;
result = egg_asn1x_encode (asn, egg_secure_realloc, n_key);
if (result == NULL)
g_warning ("couldn't encode private rsa key: %s", egg_asn1x_message (asn));
done:
egg_asn1x_destroy (asn);
gcry_mpi_release (n);
gcry_mpi_release (e);
gcry_mpi_release (d);
gcry_mpi_release (p);
gcry_mpi_release (q);
gcry_mpi_release (u);
gcry_mpi_release (tmp);
gcry_mpi_release (e1);
gcry_mpi_release (e2);
return result;
}
static gcry_mpi_t
gen_prime (unsigned int nbits, int secret, int randomlevel,
int (*extra_check)(void *, gcry_mpi_t), void *extra_check_arg)
{
gcry_mpi_t prime, ptest, pminus1, val_2, val_3, result;
int i;
unsigned int x, step;
unsigned int count1, count2;
int *mods;
/* if ( DBG_CIPHER ) */
/* log_debug ("generate a prime of %u bits ", nbits ); */
if (nbits < 16)
log_fatal ("can't generate a prime with less than %d bits\n", 16);
mods = gcry_xmalloc( no_of_small_prime_numbers * sizeof *mods );
/* Make nbits fit into gcry_mpi_t implementation. */
val_2 = mpi_alloc_set_ui( 2 );
val_3 = mpi_alloc_set_ui( 3);
prime = secret? gcry_mpi_snew ( nbits ): gcry_mpi_new ( nbits );
result = mpi_alloc_like( prime );
pminus1= mpi_alloc_like( prime );
ptest = mpi_alloc_like( prime );
count1 = count2 = 0;
for (;;)
{ /* try forvever */
int dotcount=0;
/* generate a random number */
gcry_mpi_randomize( prime, nbits, randomlevel );
/* Set high order bit to 1, set low order bit to 1. If we are
generating a secret prime we are most probably doing that
for RSA, to make sure that the modulus does have the
requested key size we set the 2 high order bits. */
mpi_set_highbit (prime, nbits-1);
if (secret)
mpi_set_bit (prime, nbits-2);
mpi_set_bit(prime, 0);
/* Calculate all remainders. */
for (i=0; (x = small_prime_numbers[i]); i++ )
mods[i] = mpi_fdiv_r_ui(NULL, prime, x);
/* Now try some primes starting with prime. */
for(step=0; step < 20000; step += 2 )
{
/* Check against all the small primes we have in mods. */
count1++;
for (i=0; (x = small_prime_numbers[i]); i++ )
{
while ( mods[i] + step >= x )
mods[i] -= x;
if ( !(mods[i] + step) )
break;
}
if ( x )
continue; /* Found a multiple of an already known prime. */
mpi_add_ui( ptest, prime, step );
/* Do a fast Fermat test now. */
count2++;
mpi_sub_ui( pminus1, ptest, 1);
gcry_mpi_powm( result, val_2, pminus1, ptest );
if ( !mpi_cmp_ui( result, 1 ) )
{
/* Not composite, perform stronger tests */
if (is_prime(ptest, 5, &count2 ))
{
if (!mpi_test_bit( ptest, nbits-1-secret ))
{
progress('\n');
log_debug ("overflow in prime generation\n");
break; /* Stop loop, continue with a new prime. */
}
if (extra_check && extra_check (extra_check_arg, ptest))
{
/* The extra check told us that this prime is
not of the caller's taste. */
progress ('/');
}
else
{
/* Got it. */
mpi_free(val_2);
mpi_free(val_3);
mpi_free(result);
mpi_free(pminus1);
mpi_free(prime);
gcry_free(mods);
return ptest;
}
}
}
if (++dotcount == 10 )
{
progress('.');
dotcount = 0;
}
}
progress(':'); /* restart with a new random value */
}
}
static void
gen_prime (gcry_mpi_t * ptest, unsigned int nbits, struct GNUNET_HashCode * hc)
{
/* Note: 2 is not included because it can be tested more easily by
* looking at bit 0. The last entry in this list is marked by a zero */
static const uint16_t small_prime_numbers[] = {
3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,
47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101,
103, 107, 109, 113, 127, 131, 137, 139, 149, 151,
157, 163, 167, 173, 179, 181, 191, 193, 197, 199,
211, 223, 227, 229, 233, 239, 241, 251, 257, 263,
269, 271, 277, 281, 283, 293, 307, 311, 313, 317,
331, 337, 347, 349, 353, 359, 367, 373, 379, 383,
389, 397, 401, 409, 419, 421, 431, 433, 439, 443,
449, 457, 461, 463, 467, 479, 487, 491, 499, 503,
509, 521, 523, 541, 547, 557, 563, 569, 571, 577,
587, 593, 599, 601, 607, 613, 617, 619, 631, 641,
643, 647, 653, 659, 661, 673, 677, 683, 691, 701,
709, 719, 727, 733, 739, 743, 751, 757, 761, 769,
773, 787, 797, 809, 811, 821, 823, 827, 829, 839,
853, 857, 859, 863, 877, 881, 883, 887, 907, 911,
919, 929, 937, 941, 947, 953, 967, 971, 977, 983,
991, 997, 1009, 1013, 1019, 1021, 1031, 1033,
1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091,
1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151,
1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213,
1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277,
1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307,
1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399,
1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451,
1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493,
1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559,
1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609,
1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667,
1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733,
1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789,
1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871,
1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931,
1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997,
1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053,
2063, 2069, 2081, 2083, 2087, 2089, 2099, 2111,
2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161,
2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243,
2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297,
2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357,
2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411,
2417, 2423, 2437, 2441, 2447, 2459, 2467, 2473,
2477, 2503, 2521, 2531, 2539, 2543, 2549, 2551,
2557, 2579, 2591, 2593, 2609, 2617, 2621, 2633,
2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687,
2689, 2693, 2699, 2707, 2711, 2713, 2719, 2729,
2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791,
2797, 2801, 2803, 2819, 2833, 2837, 2843, 2851,
2857, 2861, 2879, 2887, 2897, 2903, 2909, 2917,
2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999,
3001, 3011, 3019, 3023, 3037, 3041, 3049, 3061,
3067, 3079, 3083, 3089, 3109, 3119, 3121, 3137,
3163, 3167, 3169, 3181, 3187, 3191, 3203, 3209,
3217, 3221, 3229, 3251, 3253, 3257, 3259, 3271,
3299, 3301, 3307, 3313, 3319, 3323, 3329, 3331,
3343, 3347, 3359, 3361, 3371, 3373, 3389, 3391,
3407, 3413, 3433, 3449, 3457, 3461, 3463, 3467,
3469, 3491, 3499, 3511, 3517, 3527, 3529, 3533,
3539, 3541, 3547, 3557, 3559, 3571, 3581, 3583,
3593, 3607, 3613, 3617, 3623, 3631, 3637, 3643,
3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709,
3719, 3727, 3733, 3739, 3761, 3767, 3769, 3779,
3793, 3797, 3803, 3821, 3823, 3833, 3847, 3851,
3853, 3863, 3877, 3881, 3889, 3907, 3911, 3917,
3919, 3923, 3929, 3931, 3943, 3947, 3967, 3989,
4001, 4003, 4007, 4013, 4019, 4021, 4027, 4049,
4051, 4057, 4073, 4079, 4091, 4093, 4099, 4111,
4127, 4129, 4133, 4139, 4153, 4157, 4159, 4177,
4201, 4211, 4217, 4219, 4229, 4231, 4241, 4243,
4253, 4259, 4261, 4271, 4273, 4283, 4289, 4297,
4327, 4337, 4339, 4349, 4357, 4363, 4373, 4391,
4397, 4409, 4421, 4423, 4441, 4447, 4451, 4457,
4463, 4481, 4483, 4493, 4507, 4513, 4517, 4519,
4523, 4547, 4549, 4561, 4567, 4583, 4591, 4597,
4603, 4621, 4637, 4639, 4643, 4649, 4651, 4657,
4663, 4673, 4679, 4691, 4703, 4721, 4723, 4729,
4733, 4751, 4759, 4783, 4787, 4789, 4793, 4799,
4801, 4813, 4817, 4831, 4861, 4871, 4877, 4889,
4903, 4909, 4919, 4931, 4933, 4937, 4943, 4951,
4957, 4967, 4969, 4973, 4987, 4993, 4999,
0
};
#define DIM(v) (sizeof(v)/sizeof((v)[0]))
static int no_of_small_prime_numbers = DIM (small_prime_numbers) - 1;
gcry_mpi_t prime, pminus1, val_2, val_3, result;
unsigned int i;
unsigned int step;
unsigned int mods[no_of_small_prime_numbers];
gcry_mpi_t tmp;
gcry_mpi_t sp;
GNUNET_assert (nbits >= 16);
/* Make nbits fit into mpz_t implementation. */
val_2 = gcry_mpi_set_ui (NULL, 2);
val_3 = gcry_mpi_set_ui (NULL, 3);
prime = gcry_mpi_snew (0);
result = gcry_mpi_new (0);
pminus1 = gcry_mpi_new (0);
*ptest = gcry_mpi_new (0);
tmp = gcry_mpi_new (0);
sp = gcry_mpi_new (0);
while (1)
{
/* generate a random number */
mpz_randomize (prime, nbits, hc);
/* Set high order bit to 1, set low order bit to 1. If we are
* generating a secret prime we are most probably doing that
* for RSA, to make sure that the modulus does have the
* requested key size we set the 2 high order bits. */
gcry_mpi_set_bit (prime, nbits - 1);
gcry_mpi_set_bit (prime, nbits - 2);
gcry_mpi_set_bit (prime, 0);
/* Calculate all remainders. */
for (i = 0; i < no_of_small_prime_numbers; i++)
{
size_t written;
gcry_mpi_set_ui (sp, small_prime_numbers[i]);
gcry_mpi_div (NULL, tmp, prime, sp, -1);
mods[i] = 0;
written = sizeof (unsigned int);
GNUNET_assert (0 ==
gcry_mpi_print (GCRYMPI_FMT_USG,
(unsigned char *) &mods[i], written,
&written, tmp));
adjust ((unsigned char *) &mods[i], written, sizeof (unsigned int));
mods[i] = ntohl (mods[i]);
}
/* Now try some primes starting with prime. */
for (step = 0; step < 20000; step += 2)
{
/* Check against all the small primes we have in mods. */
for (i = 0; i < no_of_small_prime_numbers; i++)
{
uint16_t x = small_prime_numbers[i];
while (mods[i] + step >= x)
mods[i] -= x;
if (!(mods[i] + step))
break;
}
if (i < no_of_small_prime_numbers)
continue; /* Found a multiple of an already known prime. */
gcry_mpi_add_ui (*ptest, prime, step);
if (!gcry_mpi_test_bit (*ptest, nbits - 2))
break;
/* Do a fast Fermat test now. */
gcry_mpi_sub_ui (pminus1, *ptest, 1);
gcry_mpi_powm (result, val_2, pminus1, *ptest);
if ((!gcry_mpi_cmp_ui (result, 1)) && (is_prime (*ptest, 5, hc)))
{
/* Got it. */
gcry_mpi_release (sp);
gcry_mpi_release (tmp);
gcry_mpi_release (val_2);
gcry_mpi_release (val_3);
gcry_mpi_release (result);
gcry_mpi_release (pminus1);
gcry_mpi_release (prime);
return;
}
}
}
}
/*create a new MPI number with this many bytes*/
void mpiNew(int bytes,gcry_mpi_t output)
{
output = gcry_mpi_snew(bytes);
}
/****************
* Generate a key pair with a key of size NBITS
* Returns: 2 structures filled with all needed values
* and an array with n-1 factors of (p-1)
*/
static void
generate ( ELG_secret_key *sk, unsigned int nbits, gcry_mpi_t **ret_factors )
{
gcry_mpi_t p; /* the prime */
gcry_mpi_t p_min1;
gcry_mpi_t g;
gcry_mpi_t x; /* the secret exponent */
gcry_mpi_t y;
unsigned int qbits;
unsigned int xbits;
byte *rndbuf;
p_min1 = gcry_mpi_new ( nbits );
qbits = wiener_map( nbits );
if( qbits & 1 ) /* better have a even one */
qbits++;
g = mpi_alloc(1);
p = _gcry_generate_elg_prime( 0, nbits, qbits, g, ret_factors );
mpi_sub_ui(p_min1, p, 1);
/* Select a random number which has these properties:
* 0 < x < p-1
* This must be a very good random number because this is the
* secret part. The prime is public and may be shared anyway,
* so a random generator level of 1 is used for the prime.
*
* I don't see a reason to have a x of about the same size
* as the p. It should be sufficient to have one about the size
* of q or the later used k plus a large safety margin. Decryption
* will be much faster with such an x.
*/
xbits = qbits * 3 / 2;
if( xbits >= nbits )
BUG();
x = gcry_mpi_snew ( xbits );
if( DBG_CIPHER )
log_debug("choosing a random x of size %u", xbits );
rndbuf = NULL;
do
{
if( DBG_CIPHER )
progress('.');
if( rndbuf )
{ /* Change only some of the higher bits */
if( xbits < 16 ) /* should never happen ... */
{
gcry_free(rndbuf);
rndbuf = gcry_random_bytes_secure( (xbits+7)/8,
GCRY_VERY_STRONG_RANDOM );
}
else
{
char *r = gcry_random_bytes_secure( 2,
GCRY_VERY_STRONG_RANDOM );
memcpy(rndbuf, r, 2 );
gcry_free(r);
}
}
else
{
rndbuf = gcry_random_bytes_secure( (xbits+7)/8,
GCRY_VERY_STRONG_RANDOM );
}
_gcry_mpi_set_buffer( x, rndbuf, (xbits+7)/8, 0 );
mpi_clear_highbit( x, xbits+1 );
}
while( !( mpi_cmp_ui( x, 0 )>0 && mpi_cmp( x, p_min1 )<0 ) );
gcry_free(rndbuf);
y = gcry_mpi_new (nbits);
gcry_mpi_powm( y, g, x, p );
if( DBG_CIPHER )
{
progress('\n');
log_mpidump("elg p= ", p );
log_mpidump("elg g= ", g );
log_mpidump("elg y= ", y );
log_mpidump("elg x= ", x );
}
/* Copy the stuff to the key structures */
sk->p = p;
sk->g = g;
sk->y = y;
sk->x = x;
gcry_mpi_release ( p_min1 );
/* Now we can test our keys (this should never fail!) */
test_keys ( sk, nbits - 64, 0 );
}
/* Parse a private key S-expression and retutn a malloced array with
the RSA paramaters in pkcs#12 order. The caller needs to
deep-release this array. */
static gcry_mpi_t *
sexp_to_kparms (gcry_sexp_t sexp)
{
gcry_sexp_t list, l2;
const char *name;
const char *s;
size_t n;
int idx;
const char *elems;
gcry_mpi_t *array;
list = gcry_sexp_find_token (sexp, "private-key", 0 );
if(!list)
return NULL;
l2 = gcry_sexp_cadr (list);
gcry_sexp_release (list);
list = l2;
name = gcry_sexp_nth_data (list, 0, &n);
if(!name || n != 3 || memcmp (name, "rsa", 3))
{
gcry_sexp_release (list);
return NULL;
}
/* Parameter names used with RSA in the pkcs#12 order. */
elems = "nedqp--u";
array = xtrycalloc (strlen(elems) + 1, sizeof *array);
if (!array)
{
gcry_sexp_release (list);
return NULL;
}
for (idx=0, s=elems; *s; s++, idx++ )
{
if (*s == '-')
continue; /* Computed below */
l2 = gcry_sexp_find_token (list, s, 1);
if (l2)
{
array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
gcry_sexp_release (l2);
}
if (!array[idx]) /* Required parameter not found or invalid. */
{
for (idx=0; array[idx]; idx++)
gcry_mpi_release (array[idx]);
xfree (array);
gcry_sexp_release (list);
return NULL;
}
}
gcry_sexp_release (list);
array[5] = gcry_mpi_snew (0); /* compute d mod (q-1) */
gcry_mpi_sub_ui (array[5], array[3], 1);
gcry_mpi_mod (array[5], array[2], array[5]);
array[6] = gcry_mpi_snew (0); /* compute d mod (p-1) */
gcry_mpi_sub_ui (array[6], array[4], 1);
gcry_mpi_mod (array[6], array[3], array[6]);
return array;
}
