From: Rudolf Polzer <divVerent@xonotic.org>
Date: Thu, 18 Aug 2011 09:57:29 +0000 (+0200)
Subject: version 0.3: allow variable length for sign data buffer
X-Git-Tag: xonotic-v0.5.0^0
X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fd0_blind_id.git;a=commitdiff_plain;h=933873052795f6abc14deead27f0f652a7e401e1

version 0.3: allow variable length for sign data buffer
---

diff --git a/Makefile.am b/Makefile.am
index 2912c1b..aa3e6e5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -23,7 +23,7 @@ else
 libd0_blind_id_la_SOURCES += d0_bignum-gmp.c
 endif
 endif
-libd0_blind_id_la_LDFLAGS = -versioninfo 4:0:4
+libd0_blind_id_la_LDFLAGS = -versioninfo 5:0:5
 libd0_blind_id_la_CFLAGS = -fvisibility=hidden -Wold-style-definition -Wstrict-prototypes -Wsign-compare -Wdeclaration-after-statement
 library_includedir = $(includedir)/d0_blind_id
 library_include_HEADERS = d0_blind_id.h d0.h
diff --git a/configure.ac b/configure.ac
index 46853a1..b5d4e11 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([d0_blind_id], [0.2], [divVerent@xonotic.org])
+AC_INIT([d0_blind_id], [0.3], [divVerent@xonotic.org])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([-Wall foreign])
 AC_PROG_CC
diff --git a/d0_blind_id.c b/d0_blind_id.c
index a02aaa7..8852402 100644
--- a/d0_blind_id.c
+++ b/d0_blind_id.c
@@ -1052,8 +1052,8 @@ fail:
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign_internal(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, D0_BOOL with_msg, const char *message, size_t msglen, char *outbuf, size_t *outbuflen)
 {
 	d0_iobuf_t *out = NULL;
-	static unsigned char convbuf[1024];
-	static unsigned char shabuf[1024];
+	unsigned char *convbuf = NULL;
+	static unsigned char shabuf[2048];
 	d0_iobuf_t *conv = NULL;
 	size_t sz = 0;
 
@@ -1083,12 +1083,14 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign_internal(d0_
 	CHECK(d0_bignum_mod_pow(temp1, four, ctx->r, ctx->schnorr_G));
 
 	// hash it, hash it, everybody hash it
-	conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
+	conv = d0_iobuf_open_write_p((void **) &convbuf, 0);
 	CHECK(d0_iobuf_write_packet(conv, message, msglen));
 	CHECK(d0_iobuf_write_bignum(conv, temp1));
 	d0_iobuf_close(conv, &sz);
 	conv = NULL;
 	CHECK(d0_longhash_destructive(convbuf, sz, shabuf, (d0_bignum_size(temp0) + 7) / 8));
+	d0_free(convbuf);
+	convbuf = NULL;
 	CHECK(d0_bignum_import_unsigned(temp2, shabuf, (d0_bignum_size(temp0) + 7) / 8));
 	CHECK(d0_iobuf_write_bignum(out, temp2));
 
@@ -1124,7 +1126,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify_internal(d
 {
 	d0_iobuf_t *in = NULL;
 	d0_iobuf_t *conv = NULL;
-	static unsigned char convbuf[2048];
+	unsigned char *convbuf = NULL;
 	static unsigned char shabuf[2048];
 	size_t sz;
 
@@ -1202,12 +1204,14 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify_internal(d
 	CHECK_ASSIGN(temp3, d0_bignum_mod_mul(temp3, temp1, temp2, ctx->schnorr_G)); // temp3 now is g^r
 
 	// hash it, hash it, everybody hash it
-	conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
+	conv = d0_iobuf_open_write_p((void **) &convbuf, 0);
 	CHECK(d0_iobuf_write_packet(conv, msg, *msglen));
 	CHECK(d0_iobuf_write_bignum(conv, temp3));
 	d0_iobuf_close(conv, &sz);
 	conv = NULL;
 	CHECK(d0_longhash_destructive(convbuf, sz, shabuf, (d0_bignum_size(temp4) + 7) / 8));
+	d0_free(convbuf);
+	convbuf = NULL;
 	CHECK(d0_bignum_import_unsigned(temp1, shabuf, (d0_bignum_size(temp4) + 7) / 8));
 
 	// verify signature
diff --git a/d0_iobuf.c b/d0_iobuf.c
index ce8e58d..4fa37e2 100644
--- a/d0_iobuf.c
+++ b/d0_iobuf.c
@@ -41,8 +41,10 @@ struct d0_iobuf_s
 {
 	const unsigned char *inbuf;
 	unsigned char *outbuf;
+	unsigned char **outbufp;
 	size_t inpos, outpos, inbuflen, outbuflen;
 	D0_BOOL ok;
+	D0_BOOL pdata;
 };
 
 d0_iobuf_t *d0_iobuf_open_read(const void *buf, size_t len)
@@ -50,6 +52,7 @@ d0_iobuf_t *d0_iobuf_open_read(const void *buf, size_t len)
 	d0_iobuf_t *b = d0_malloc(sizeof(d0_iobuf_t));
 	b->inbuf = (const unsigned char *) buf;
 	b->outbuf = NULL;
+	b->outbufp = NULL;
 	b->inpos = b->outpos = 0;
 	b->inbuflen = len;
 	b->outbuflen = 0;
@@ -62,8 +65,22 @@ d0_iobuf_t *d0_iobuf_open_write(void *buf, size_t len)
 	d0_iobuf_t *b = d0_malloc(sizeof(d0_iobuf_t));
 	b->inbuf = (const unsigned char *) buf;
 	b->outbuf = (unsigned char *) buf;
+	b->outbufp = NULL;
 	b->inpos = b->outpos = 0;
-	b->inbuflen = len;
+	b->inbuflen = 0;
+	b->outbuflen = len;
+	b->ok = 1;
+	return b;
+}
+
+d0_iobuf_t *d0_iobuf_open_write_p(void **buf, size_t len)
+{
+	d0_iobuf_t *b = d0_malloc(sizeof(d0_iobuf_t));
+	b->inbuf = (const unsigned char *) *buf;
+	b->outbuf = (unsigned char *) *buf;
+	b->outbufp = (unsigned char **) buf;
+	b->inpos = b->outpos = 0;
+	b->inbuflen = 0;
 	b->outbuflen = len;
 	b->ok = 1;
 	return b;
@@ -81,6 +98,27 @@ D0_BOOL d0_iobuf_close(d0_iobuf_t *buf, size_t *len)
 size_t d0_iobuf_write_raw(d0_iobuf_t *buf, const void *s, size_t n)
 {
 	size_t nreal = n;
+
+	// if packet doesn't fit, expand buffer
+	if(buf->outbufp && nreal > buf->outbuflen - buf->outpos)
+	{
+		size_t newsize = 1;
+		while(nreal + buf->outpos > newsize)
+			newsize <<= 1;
+
+		{
+			char *newbuf = d0_malloc(newsize);
+			if(buf->outbuf)
+			{
+				memcpy(newbuf, buf->outbuf, buf->outbuflen);
+				d0_free(buf->outbuf);
+			}
+			buf->outbuf = newbuf;
+			*buf->outbufp = newbuf;
+			buf->outbuflen = newsize;
+		}
+	}
+
 	if(nreal > buf->outbuflen - buf->outpos)
 	{
 		buf->ok = 0;
@@ -88,6 +126,7 @@ size_t d0_iobuf_write_raw(d0_iobuf_t *buf, const void *s, size_t n)
 	}
 	memcpy(buf->outbuf + buf->outpos, s, nreal);
 	buf->outpos += nreal;
+	buf->inbuflen = buf->outpos;
 	return nreal;
 }
 
diff --git a/d0_iobuf.h b/d0_iobuf.h
index d774e67..9705e2c 100644
--- a/d0_iobuf.h
+++ b/d0_iobuf.h
@@ -40,8 +40,9 @@
 
 typedef struct d0_iobuf_s d0_iobuf_t;
 
-D0_WARN_UNUSED_RESULT d0_iobuf_t *d0_iobuf_open_read(const void *buf, size_t len); // note: can read AND write!
+D0_WARN_UNUSED_RESULT d0_iobuf_t *d0_iobuf_open_read(const void *buf, size_t len); // note: can read
 D0_WARN_UNUSED_RESULT d0_iobuf_t *d0_iobuf_open_write(void *buf, size_t len); // note: can read AND write!
+D0_WARN_UNUSED_RESULT d0_iobuf_t *d0_iobuf_open_write_p(void **buf, size_t len); // note: can read AND write!
 D0_WARN_UNUSED_RESULT D0_BOOL d0_iobuf_conv_base64_in(d0_iobuf_t *buf);
 D0_WARN_UNUSED_RESULT D0_BOOL d0_iobuf_conv_base64_out(d0_iobuf_t *buf);
 D0_BOOL d0_iobuf_close(d0_iobuf_t *buf, size_t *len); // don't warn