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[GNUnet-SVN] r31820 - gnunet/src/secretsharing
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From: |
gnunet |
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Subject: |
[GNUnet-SVN] r31820 - gnunet/src/secretsharing |
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Date: |
Tue, 7 Jan 2014 12:10:06 +0100 |
Author: dold
Date: 2014-01-07 12:10:05 +0100 (Tue, 07 Jan 2014)
New Revision: 31820
Modified:
gnunet/src/secretsharing/gnunet-service-secretsharing.c
gnunet/src/secretsharing/secretsharing_protocol.h
Log:
- correctly adjust buffer when printing MPIs
- fix confusion between paillier and elgamal field elements
Modified: gnunet/src/secretsharing/gnunet-service-secretsharing.c
===================================================================
--- gnunet/src/secretsharing/gnunet-service-secretsharing.c 2014-01-07
10:40:30 UTC (rev 31819)
+++ gnunet/src/secretsharing/gnunet-service-secretsharing.c 2014-01-07
11:10:05 UTC (rev 31820)
@@ -44,13 +44,8 @@
struct GNUNET_PeerIdentity peer;
/**
- * g-component of the peer's paillier public key.
+ * The peer's paillier public key.
*/
- gcry_mpi_t paillier_g;
-
- /**
- * mu-component of the peer's paillier public key.
- */
gcry_mpi_t paillier_n;
/**
@@ -318,16 +313,48 @@
*/
static struct GNUNET_SERVER_Handle *srv;
+
/**
- * Print a field element in a fixed-size buffer.
+ * If target != size, move @a target bytes to the end of the size-sized
+ * buffer and zero out the first @a target - @a size bytes.
+ *
+ * @param buf original buffer
+ * @param size number of bytes in @a buf
+ * @param target target size of the buffer
*/
static void
-print_field_element (void *buf, gcry_mpi_t x)
+adjust (unsigned char *buf,
+ size_t size,
+ size_t target)
{
- GNUNET_assert (0);
+ if (size < target)
+ {
+ memmove (&buf[target - size], buf, size);
+ memset (buf, 0, target - size);
+ }
}
+/**
+ * Print an MPI to a buffer, so that is contains the MPI's
+ * the little endian representation of size @a size.
+ *
+ * @param buf buffer to write to
+ * @param x mpi to be written in the buffer
+ * @param bytes how many bytes should the value use
+ * @param
+ */
+static void
+print_mpi_fixed (void *buf, gcry_mpi_t x, size_t size)
+{
+ size_t written;
+ GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
+ buf, size, &written,
+ x));
+ adjust (buf, written, size);
+}
+
+
static struct KeygenPeerInfo *
get_keygen_peer_info (const struct KeygenSession *ks,
const struct GNUNET_PeerIdentity *peer)
@@ -499,13 +526,12 @@
* Uses the simplified key generation of Jonathan Katz, Yehuda Lindell,
* "Introduction to Modern Cryptography: Principles and Protocols".
*
- * @param g g-component of public key
* @param n n-component of public key
* @param lambda lambda-component of private key
* @param mu mu-componenent of private key
*/
static void
-paillier_create (gcry_mpi_t g, gcry_mpi_t n, gcry_mpi_t lambda, gcry_mpi_t mu)
+paillier_create (gcry_mpi_t n, gcry_mpi_t lambda, gcry_mpi_t mu)
{
gcry_mpi_t p;
gcry_mpi_t q;
@@ -521,7 +547,6 @@
GNUNET_assert (0 == gcry_prime_generate (&q, PAILLIER_BITS / 2, 0, NULL,
NULL, NULL,
GCRY_WEAK_RANDOM, 0));
gcry_mpi_mul (n, p, q);
- gcry_mpi_add_ui (g, n, 1);
// compute phi(n) = (p-1)(q-1)
gcry_mpi_sub_ui (phi, p, 1);
gcry_mpi_sub_ui (tmp, q, 1);
@@ -542,18 +567,21 @@
*
* @param c resulting ciphertext
* @param m plaintext to encrypt
- * @param g g-component of public key
* @param n n-component of public key
*/
static void
-paillier_encrypt (gcry_mpi_t c, gcry_mpi_t m, gcry_mpi_t g, gcry_mpi_t n)
+paillier_encrypt (gcry_mpi_t c, gcry_mpi_t m, gcry_mpi_t n)
{
gcry_mpi_t n_square;
gcry_mpi_t r;
+ gcry_mpi_t g;
GNUNET_assert (0 != (n_square = gcry_mpi_new (0)));
GNUNET_assert (0 != (r = gcry_mpi_new (0)));
+ GNUNET_assert (0 != (g = gcry_mpi_new (0)));
+ gcry_mpi_add_ui (g, n, 1);
+
gcry_mpi_mul (n_square, n, n);
// generate r < n
@@ -617,9 +645,9 @@
ks->presecret_polynomial = GNUNET_malloc (ks->threshold * sizeof
(gcry_mpi_t));
for (i = 0; i < ks->threshold; i++)
{
- ks->presecret_polynomial[i] = gcry_mpi_new (PAILLIER_BITS);
+ ks->presecret_polynomial[i] = gcry_mpi_new (GNUNET_SECRETSHARING_KEY_BITS);
GNUNET_assert (0 != ks->presecret_polynomial[i]);
- gcry_mpi_randomize (ks->presecret_polynomial[i], PAILLIER_BITS,
+ gcry_mpi_randomize (ks->presecret_polynomial[i],
GNUNET_SECRETSHARING_KEY_BITS,
GCRY_WEAK_RANDOM);
}
}
@@ -681,8 +709,6 @@
return;
}
- GNUNET_assert (0 == gcry_mpi_scan (&info->paillier_g, GCRYMPI_FMT_USG,
- &d->pubkey.g, sizeof d->pubkey.g, NULL));
GNUNET_assert (0 == gcry_mpi_scan (&info->paillier_n, GCRYMPI_FMT_USG,
&d->pubkey.n, sizeof d->pubkey.n, NULL));
GNUNET_assert (0 == gcry_mpi_scan (&info->presecret_commitment,
GCRYMPI_FMT_USG,
@@ -731,8 +757,8 @@
GNUNET_log (GNUNET_ERROR_TYPE_INFO, "round2 conclude\n");
- GNUNET_assert (0 != (s = gcry_mpi_new (PAILLIER_BITS)));
- GNUNET_assert (0 != (h = gcry_mpi_new (PAILLIER_BITS)));
+ GNUNET_assert (0 != (s = gcry_mpi_new (GNUNET_SECRETSHARING_KEY_BITS)));
+ GNUNET_assert (0 != (h = gcry_mpi_new (GNUNET_SECRETSHARING_KEY_BITS)));
// multiplicative identity
gcry_mpi_set_ui (s, 1);
@@ -762,8 +788,8 @@
}
}
- gcry_mpi_print (GCRYMPI_FMT_USG, (void *) &share->my_share, PAILLIER_BITS /
8, NULL, s);
- gcry_mpi_print (GCRYMPI_FMT_USG, (void *) &share->public_key, PAILLIER_BITS
/ 8, NULL, s);
+ print_mpi_fixed (&share->my_share, s, GNUNET_SECRETSHARING_KEY_BITS / 8);
+ print_mpi_fixed (&share->public_key, h, GNUNET_SECRETSHARING_KEY_BITS / 8);
GNUNET_log (GNUNET_ERROR_TYPE_INFO, "keygen successful with %u peers\n",
share->num_peers);
@@ -803,12 +829,12 @@
gcry_mpi_t idx;
gcry_mpi_t v;
- GNUNET_assert (0 != (v = gcry_mpi_new (PAILLIER_BITS)));
- GNUNET_assert (0 != (idx = gcry_mpi_new (PAILLIER_BITS)));
+ GNUNET_assert (0 != (v = gcry_mpi_new (GNUNET_SECRETSHARING_KEY_BITS)));
+ GNUNET_assert (0 != (idx = gcry_mpi_new (GNUNET_SECRETSHARING_KEY_BITS)));
element_size = (sizeof (struct GNUNET_SECRETSHARING_KeygenRevealData) +
- 2 * PAILLIER_BITS / 8 * ks->num_peers +
- 1 * PAILLIER_BITS / 8 * ks->threshold);
+ 2 * GNUNET_SECRETSHARING_KEY_BITS / 8 * ks->num_peers +
+ 1 * GNUNET_SECRETSHARING_KEY_BITS / 8 * ks->threshold);
element = GNUNET_malloc (sizeof (struct GNUNET_SET_Element) + element_size);
element->size = element_size;
@@ -830,8 +856,8 @@
horner_eval (v, ks->presecret_polynomial, ks->threshold, idx, elgamal_p);
// take g to the result
gcry_mpi_powm (v, elgamal_g, v, elgamal_p);
- gcry_mpi_print (GCRYMPI_FMT_USG, pos, (size_t) remaining, NULL, v);
- pos += PAILLIER_BITS / 8;
+ print_mpi_fixed (pos, v, GNUNET_SECRETSHARING_KEY_BITS / 8);
+ pos += GNUNET_SECRETSHARING_KEY_BITS / 8;
}
// encrypted pre-shares
@@ -842,10 +868,9 @@
if (GNUNET_NO == ks->info[i].round1_valid)
gcry_mpi_set_ui (v, 0);
else
- paillier_encrypt (v, ks->presecret_polynomial[0],
- ks->info[i].paillier_g, ks->info[i].paillier_g);
- gcry_mpi_print (GCRYMPI_FMT_USG, pos, (size_t) remaining, NULL, v);
- pos += PAILLIER_BITS / 8;
+ paillier_encrypt (v, ks->presecret_polynomial[0],
ks->info[i].paillier_n);
+ print_mpi_fixed (pos, v, GNUNET_SECRETSHARING_KEY_BITS / 8);
+ pos += GNUNET_SECRETSHARING_KEY_BITS / 8;
}
// exponentiated coefficients
@@ -854,8 +879,8 @@
ptrdiff_t remaining = last_pos - pos;
GNUNET_assert (remaining > 0);
gcry_mpi_powm (v, elgamal_g, ks->presecret_polynomial[i], elgamal_p);
- gcry_mpi_print (GCRYMPI_FMT_USG, pos, (size_t) remaining, NULL, v);
- pos += PAILLIER_BITS / 8;
+ print_mpi_fixed (pos, v, GNUNET_SECRETSHARING_KEY_BITS / 8);
+ pos += GNUNET_SECRETSHARING_KEY_BITS / 8;
}
d->purpose.size = htonl (element_size - offsetof (struct
GNUNET_SECRETSHARING_KeygenRevealData, purpose));
@@ -888,8 +913,8 @@
}
expected_element_size = (sizeof (struct
GNUNET_SECRETSHARING_KeygenRevealData) +
- 2 * PAILLIER_BITS / 8 * ks->num_peers +
- 1 * PAILLIER_BITS / 8 * ks->threshold);
+ 2 * GNUNET_SECRETSHARING_KEY_BITS / 8 * ks->num_peers +
+ 1 * GNUNET_SECRETSHARING_KEY_BITS / 8 * ks->threshold);
if (element->size != expected_element_size)
{
@@ -932,16 +957,16 @@
pos = (void *) &d[1];
// skip exponentiated pre-shares
- pos += PAILLIER_BITS / 8 * ks->num_peers;
+ pos += GNUNET_SECRETSHARING_KEY_BITS / 8 * ks->num_peers;
// skip encrypted pre-shares
pos += PAILLIER_BITS / 8 * ks->num_peers;
// the first exponentiated coefficient is the public key share
GNUNET_assert (0 == gcry_mpi_scan (&info->public_key_share, GCRYMPI_FMT_USG,
- pos, PAILLIER_BITS / 8, NULL));
+ pos, GNUNET_SECRETSHARING_KEY_BITS / 8,
NULL));
pos = (void *) &d[1];
// skip exp. pre-shares
- pos += PAILLIER_BITS / 8 * ks->num_peers;
+ pos += GNUNET_SECRETSHARING_KEY_BITS / 8 * ks->num_peers;
// skip to the encrypted value for our peer
pos += PAILLIER_BITS / 8 * ks->local_peer_idx;
@@ -1013,7 +1038,7 @@
// g^a_{i,0}
gcry_mpi_t v;
// big-endian representation of 'v'
- unsigned char v_data[PAILLIER_BITS / 8];
+ unsigned char v_data[GNUNET_SECRETSHARING_KEY_BITS / 8];
element = GNUNET_malloc (sizeof *element + sizeof *d);
d = (void *) &element[1];
@@ -1026,28 +1051,17 @@
d->peer = my_peer;
- GNUNET_assert (0 != (v = gcry_mpi_new (PAILLIER_BITS)));
+ GNUNET_assert (0 != (v = gcry_mpi_new (GNUNET_SECRETSHARING_KEY_BITS)));
gcry_mpi_powm (v, elgamal_g, ks->presecret_polynomial[0], elgamal_p);
- GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
- v_data, PAILLIER_BITS / 8, NULL,
- v));
+ print_mpi_fixed (v_data, v, GNUNET_SECRETSHARING_KEY_BITS);
- GNUNET_CRYPTO_hash (v_data, PAILLIER_BITS / 8, &d->commitment);
+ GNUNET_CRYPTO_hash (v_data, GNUNET_SECRETSHARING_KEY_BITS / 8,
&d->commitment);
- /*
+ print_mpi_fixed (d->pubkey.n, ks->info[ks->local_peer_idx].paillier_n,
+ PAILLIER_BITS / 8);
- GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
- (unsigned char *) d->pubkey.g,
PAILLIER_BITS / 8, NULL,
-
ks->info[ks->local_peer_idx].paillier_g));
-
- GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
- (unsigned char *) d->pubkey.n,
PAILLIER_BITS / 8, NULL,
-
ks->info[ks->local_peer_idx].paillier_n));
-
- */
-
d->purpose.size = htonl ((sizeof *d) - offsetof (struct
GNUNET_SECRETSHARING_KeygenCommitData, purpose));
d->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DKG1);
GNUNET_assert (GNUNET_OK == GNUNET_CRYPTO_eddsa_sign (my_peer_private_key,
&d->purpose, &d->signature));
@@ -1105,13 +1119,11 @@
for (i = 0; i < ks->num_peers; i++)
ks->info[i].peer = ks->peers[i];
- GNUNET_assert (0 != (ks->info[ks->local_peer_idx].paillier_g = mpi_new (0)));
GNUNET_assert (0 != (ks->info[ks->local_peer_idx].paillier_n = mpi_new (0)));
GNUNET_assert (0 != (ks->paillier_lambda = mpi_new (0)));
GNUNET_assert (0 != (ks->paillier_mu = mpi_new (0)));
- paillier_create (ks->info[ks->local_peer_idx].paillier_g,
- ks->info[ks->local_peer_idx].paillier_n,
+ paillier_create (ks->info[ks->local_peer_idx].paillier_n,
ks->paillier_lambda,
ks->paillier_mu);
@@ -1176,14 +1188,14 @@
}
GNUNET_assert (0 == gcry_mpi_scan (&c_2, GCRYMPI_FMT_USG,
ds->ciphertext.c2_bits,
- PAILLIER_BITS / 8, NULL));
+ GNUNET_SECRETSHARING_KEY_BITS / 8, NULL));
// m <- c_2 / m
gcry_mpi_invm (m, m, elgamal_p);
gcry_mpi_mulm (m, c_2, m, elgamal_p);
ev = GNUNET_MQ_msg (msg,
GNUNET_MESSAGE_TYPE_SECRETSHARING_CLIENT_DECRYPT_DONE);
- print_field_element (&msg->plaintext, m);
+ print_mpi_fixed (&msg->plaintext, m, GNUNET_SECRETSHARING_KEY_BITS / 8);
msg->success = htonl (1);
GNUNET_MQ_send (ds->client_mq, ev);
@@ -1236,7 +1248,7 @@
// FIXME: check NIZP first
GNUNET_assert (0 == gcry_mpi_scan (&info->partial_decryption,
- GCRYMPI_FMT_USG, &d->partial_decryption,
PAILLIER_BITS / 8, NULL));
+ GCRYMPI_FMT_USG, &d->partial_decryption,
GNUNET_SECRETSHARING_KEY_BITS / 8, NULL));
}
static void
@@ -1247,8 +1259,8 @@
gcry_mpi_t x;
gcry_mpi_t s;
- GNUNET_assert (0 == gcry_mpi_scan (&x, GCRYMPI_FMT_USG,
ds->ciphertext.c1_bits, PAILLIER_BITS / 8, NULL));
- GNUNET_assert (0 == gcry_mpi_scan (&s, GCRYMPI_FMT_USG,
&ds->share->my_share, PAILLIER_BITS / 8, NULL));
+ GNUNET_assert (0 == gcry_mpi_scan (&x, GCRYMPI_FMT_USG,
ds->ciphertext.c1_bits, GNUNET_SECRETSHARING_KEY_BITS / 8, NULL));
+ GNUNET_assert (0 == gcry_mpi_scan (&s, GCRYMPI_FMT_USG,
&ds->share->my_share, GNUNET_SECRETSHARING_KEY_BITS / 8, NULL));
gcry_mpi_powm (x, x, s, elgamal_p);
@@ -1260,7 +1272,7 @@
d.purpose.purpose = htonl
(GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DECRYPTION);
GNUNET_CRYPTO_eddsa_sign (my_peer_private_key, &d.purpose, &d.signature);
- print_field_element (&d.partial_decryption, x);
+ print_mpi_fixed (&d.partial_decryption, x, GNUNET_SECRETSHARING_KEY_BITS /
8);
GNUNET_CONSENSUS_insert (ds->consensus, &element, NULL, NULL);
}
Modified: gnunet/src/secretsharing/secretsharing_protocol.h
===================================================================
--- gnunet/src/secretsharing/secretsharing_protocol.h 2014-01-07 10:40:30 UTC
(rev 31819)
+++ gnunet/src/secretsharing/secretsharing_protocol.h 2014-01-07 11:10:05 UTC
(rev 31820)
@@ -48,12 +48,6 @@
{
/**
* Network order representation of the
- * g-component.
- */
- uint32_t g[PAILLIER_BITS / 8 / sizeof (uint32_t)];
-
- /**
- * Network order representation of the
* n-component.
*/
uint32_t n[PAILLIER_BITS / 8 / sizeof (uint32_t)];
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