X-Git-Url: http://git.xonotic.org/?a=blobdiff_plain;f=d0_blind_id.c;h=bc9db70bf00436fcadeccf26d66e84879a970075;hb=0d9c60c64a7628d79882fd8ceb8d3aafc3548688;hp=cc85624e5cc8e680f8251dc09da0366135e81496;hpb=4145420d34f05696e610e2f414874312ad572479;p=xonotic%2Fd0_blind_id.git

diff --git a/d0_blind_id.c b/d0_blind_id.c
index cc85624..bc9db70 100644
--- a/d0_blind_id.c
+++ b/d0_blind_id.c
@@ -1,21 +1,37 @@
 /*
-Blind-ID library for user identification using RSA blind signatures
-Copyright (C) 2010  Rudolf Polzer
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Lesser General Public
-License as published by the Free Software Foundation; either
-version 2.1 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Lesser General Public License for more details.
-
-You should have received a copy of the GNU Lesser General Public
-License along with this library; if not, write to the Free Software
-Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-*/
+ * FILE:	d0_blind_id.c
+ * AUTHOR:	Rudolf Polzer - divVerent@xonotic.org
+ * 
+ * Copyright (c) 2010, Rudolf Polzer
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTOR(S) BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Format:commit %H$
+ * $Id$
+ */
 
 #include "d0_blind_id.h"
 
@@ -88,9 +104,9 @@ struct d0_blind_id_s
 
 static d0_bignum_t *zero, *one, *four, *temp0, *temp1, *temp2, *temp3, *temp4;
 
-void d0_blind_id_INITIALIZE(void)
+WARN_UNUSED_RESULT BOOL d0_blind_id_INITIALIZE(void)
 {
-	d0_bignum_INITIALIZE();
+	CHECK(d0_bignum_INITIALIZE());
 	CHECK_ASSIGN(zero, d0_bignum_int(zero, 0));
 	CHECK_ASSIGN(one, d0_bignum_int(one, 1));
 	CHECK_ASSIGN(four, d0_bignum_int(four, 4));
@@ -99,8 +115,9 @@ void d0_blind_id_INITIALIZE(void)
 	CHECK_ASSIGN(temp2, d0_bignum_int(temp2, 0));
 	CHECK_ASSIGN(temp3, d0_bignum_int(temp3, 0));
 	CHECK_ASSIGN(temp4, d0_bignum_int(temp4, 0));
+	return 1;
 fail:
-	;
+	return 0;
 }
 
 void d0_blind_id_SHUTDOWN(void)
@@ -746,18 +763,8 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_
 	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));
-		}
-	}
+	MPCHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
+	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
@@ -979,6 +986,31 @@ fail:
 	return 0;
 }
 
+WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_generate_missing_signature(d0_blind_id_t *ctx)
+{
+	size_t sz;
+	static unsigned char shabuf[2048];
+
+	REPLACING(schnorr_H_g_to_s_signature);
+	USING(schnorr_g_to_s); USING(rsa_d); USING(rsa_n);
+
+	// we will actually sign SHA(4^s) to prevent a malleability attack!
+	CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s));
+	sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting"
+	if(sz > sizeof(shabuf))
+		sz = sizeof(shabuf);
+	CHECK(d0_longhash_destructive(temp2, shabuf, sz));
+	CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz));
+
+	// + 7 / 8 is too large, so let's mod it
+	CHECK(d0_bignum_divmod(NULL, temp1, temp2, ctx->rsa_n));
+	CHECK(d0_bignum_mod_pow(ctx->schnorr_H_g_to_s_signature, temp1, ctx->rsa_d, ctx->rsa_n));
+	return 1;
+
+fail:
+	return 0;
+}
+
 WARN_UNUSED_RESULT BOOL d0_blind_id_fingerprint64_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
 {
 	d0_iobuf_t *out = NULL;
@@ -986,11 +1018,15 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_fingerprint64_public_id(const d0_blind_id_t
 	d0_iobuf_t *conv = NULL;
 	size_t sz, n;
 
+	USING(rsa_n);
+	USING(rsa_e);
 	USING(schnorr_g_to_s);
 
 	out = d0_iobuf_open_write(outbuf, *outbuflen);
 	conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
 
+	CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_n));
+	CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_e));
 	CHECK(d0_iobuf_write_bignum(conv, ctx->schnorr_g_to_s));
 	CHECK(d0_iobuf_close(conv, &sz));
 	conv = NULL;