From: Rudolf Polzer <divverent@alientrap.org>
Date: Thu, 5 Aug 2010 07:43:23 +0000 (+0200)
Subject: un-debianize libd0_blind_id's RNG on Win32
X-Git-Tag: xonotic-v0.1.0preview~38^2~1
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=33e9bad93fe86f8ab2adde7d0f70bc39187087c5;p=xonotic%2Fd0_blind_id.git

un-debianize libd0_blind_id's RNG on Win32
---

diff --git a/d0_bignum-gmp.c b/d0_bignum-gmp.c
index 6a2f703..5f0babc 100644
--- a/d0_bignum-gmp.c
+++ b/d0_bignum-gmp.c
@@ -17,6 +17,11 @@ License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+#ifdef WIN32
+#include <windows.h>
+#include <wincrypt.h>
+#endif
+
 #include "d0_bignum.h"
 
 #include <gmp.h>
@@ -33,26 +38,43 @@ static d0_bignum_t temp;
 
 #include <time.h>
 #include <stdio.h>
+
 void d0_bignum_INITIALIZE(void)
 {
 	FILE *f;
+	unsigned char buf[256];
 	d0_bignum_init(&temp);
 	gmp_randinit_mt(RANDSTATE);
 	gmp_randseed_ui(RANDSTATE, time(NULL));
+	* (time_t *) (&buf[0]) = time(0); // if everything else fails, we use the current time + uninitialized data
+#ifdef WIN32
+	{
+		HCRYPTPROV hCryptProv;
+		if(CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
+		{
+			if(!CryptGenRandom(hCryptProv, sizeof(buf), (PBYTE) &buf[0]))
+				fprintf(stderr, "WARNING: could not initialize random number generator (CryptGenRandom failed)\n");
+		}
+		else
+			fprintf(stderr, "WARNING: could not initialize random number generator (CryptAcquireContext failed)\n");
+	}
+#else
 	f = fopen("/dev/urandom", "rb");
 	if(!f)
 		f = fopen("/dev/random", "rb");
 	if(f)
 	{
-		unsigned char buf[256];
 		setbuf(f, NULL);
-		if(fread(buf, sizeof(buf), 1, f) == 1)
-		{
-			mpz_import(temp.z, sizeof(buf), 1, 1, 0, 0, buf);
-			gmp_randseed(RANDSTATE, temp.z);
-		}
+		if(fread(buf, sizeof(buf), 1, f) != 1)
+			fprintf(stderr, "WARNING: could not initialize random number generator (read from random device failed)\n");
 		fclose(f);
 	}
+	else
+		fprintf(stderr, "WARNING: could not initialize random number generator (no random device found)\n");
+#endif
+
+	mpz_import(temp.z, sizeof(buf), 1, 1, 0, 0, buf);
+	gmp_randseed(RANDSTATE, temp.z);
 }
 
 void d0_bignum_SHUTDOWN(void)
diff --git a/d0_blind_id.c b/d0_blind_id.c
index c71c88b..cc85624 100644
--- a/d0_blind_id.c
+++ b/d0_blind_id.c
@@ -80,6 +80,8 @@ struct d0_blind_id_s
 
 #define CHECK(x) do { if(!(x)) goto fail; } while(0)
 #define CHECK_ASSIGN(var, value) do { d0_bignum_t *val; val = value; if(!val) goto fail; var = val; } while(0)
+#define MPCHECK(x) do { if(!failed) if(!(x)) failed = 1; } while(0)
+#define MPCHECK_ASSIGN(var, value) do { if(!failed) { d0_bignum_t *val; val = value; if(val) var = val; else failed = 1; } } while(0)
 
 #define USING(x) if(!(ctx->x)) return 0
 #define REPLACING(x)
@@ -712,6 +714,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_
 	static unsigned char convbuf[1024];
 	d0_iobuf_t *conv = NULL;
 	size_t sz = 0;
+	BOOL failed = 0;
 
 	// temps: temp0 order, temp0 4^r
 	if(is_first)
@@ -736,14 +739,27 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_
 	// generate random number r; x = g^r; send hash of x, remember r, forget x
 	CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
 	CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0));
-	CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
+	//CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
 
 	// initialize Signed Diffie Hellmann
-	CHECK(d0_dl_get_order(temp1, ctx->schnorr_G));
-	CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp1));
-	CHECK_ASSIGN(ctx->g_to_t, d0_bignum_mod_pow(ctx->g_to_t, four, ctx->t, ctx->schnorr_G));
+	// we already have the group order in temp1
+	CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp0));
 	// can we SOMEHOW do this with just one mod_pow?
 
+#pragma omp parallel default(shared) reduction(||:failed)
+#pragma omp sections
+	{
+#pragma omp section
+		{
+			MPCHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
+		}
+#pragma omp section
+		{
+			MPCHECK_ASSIGN(ctx->g_to_t, d0_bignum_mod_pow(ctx->g_to_t, four, ctx->t, ctx->schnorr_G));
+		}
+	}
+	CHECK(!failed);
+
 	// hash it, hash it, everybody hash it
 	conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
 	CHECK(d0_iobuf_write_bignum(conv, temp0));