patches/small_records.patch

diff --git openssl-0.9.8m/ssl/d1_pkt.c openssl-0.9.8m/ssl/d1_pkt.c
index ca2d73f..2af5272 100644
--- openssl-0.9.8m/ssl/d1_pkt.c
+++ openssl-0.9.8m/ssl/d1_pkt.c
@@ -571,6 +571,24 @@ again:
 			goto again;
 			}
 
+		/* If we receive a valid record larger than the current buffer size,
+		 * allocate some memory for it.
+		 */
+		if (rr->length > s->s3->rbuf.len - DTLS1_RT_HEADER_LENGTH)
+			{
+			unsigned char *pp;
+			unsigned int newlen = rr->length + DTLS1_RT_HEADER_LENGTH;
+			if ((pp=OPENSSL_realloc(s->s3->rbuf.buf, newlen))==NULL)
+				{
+				SSLerr(SSL_F_DTLS1_GET_RECORD,ERR_R_MALLOC_FAILURE);
+				return(-1);
+				}
+			p = pp + (p - s->s3->rbuf.buf);
+			s->s3->rbuf.buf=pp;
+			s->s3->rbuf.len=newlen;
+			s->packet= &(s->s3->rbuf.buf[0]);
+			}
+
 		s->client_version = version;
 		/* now s->rstate == SSL_ST_READ_BODY */
 		}
@@ -1300,6 +1318,7 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
 	SSL3_BUFFER *wb;
 	SSL_SESSION *sess;
 	int bs;
+	unsigned int len_with_overhead = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD;
 
 	/* first check if there is a SSL3_BUFFER still being written
 	 * out.  This will happen with non blocking IO */
@@ -1309,6 +1328,16 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
 		return(ssl3_write_pending(s,type,buf,len));
 		}
 
+	if (s->s3->wbuf.len < len_with_overhead)
+		{
+		if ((p=OPENSSL_realloc(s->s3->wbuf.buf, len_with_overhead)) == NULL) {
+			SSLerr(SSL_F_DO_DTLS1_WRITE,ERR_R_MALLOC_FAILURE);
+			goto err;
+		}
+		s->s3->wbuf.buf = p;
+		s->s3->wbuf.len = len_with_overhead;
+		}
+
 	/* If we have an alert to send, lets send it */
 	if (s->s3->alert_dispatch)
 		{
diff --git openssl-0.9.8m/ssl/s23_srvr.c openssl-0.9.8m/ssl/s23_srvr.c
index be05911..42f7de4 100644
--- openssl-0.9.8m/ssl/s23_srvr.c
+++ openssl-0.9.8m/ssl/s23_srvr.c
@@ -412,8 +412,13 @@ int ssl23_get_client_hello(SSL *s)
 		v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
 		v[1] = p[4];
 
+/* The SSL2 protocol allows n to be larger, just pick
+ * a reasonable buffer size. */
+#if SSL3_RT_DEFAULT_PACKET_SIZE < 1024*4 - SSL3_RT_DEFAULT_WRITE_OVERHEAD
+#error "SSL3_RT_DEFAULT_PACKET_SIZE is too small."
+#endif
 		n=((p[0]&0x7f)<<8)|p[1];
-		if (n > (1024*4))
+		if (n > SSL3_RT_DEFAULT_PACKET_SIZE - 2)
 			{
 			SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
 			goto err;
diff --git openssl-0.9.8m/ssl/s3_both.c openssl-0.9.8m/ssl/s3_both.c
index 7f46225..73f6002 100644
--- openssl-0.9.8m/ssl/s3_both.c
+++ openssl-0.9.8m/ssl/s3_both.c
@@ -631,11 +631,18 @@ int ssl3_setup_buffers(SSL *s)
 
 	if (s->s3->rbuf.buf == NULL)
 		{
-		if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
-			extra=SSL3_RT_MAX_EXTRA;
+		if (SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS)
+			{
+			len = SSL3_RT_DEFAULT_PACKET_SIZE;
+			}
 		else
-			extra=0;
-		len = SSL3_RT_MAX_PACKET_SIZE + extra;
+			{
+			if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
+				extra=SSL3_RT_MAX_EXTRA;
+			else
+				extra=0;
+			len = SSL3_RT_MAX_PACKET_SIZE + extra;
+			}
 		if ((p=OPENSSL_malloc(len)) == NULL)
 			goto err;
 		s->s3->rbuf.buf = p;
@@ -644,8 +651,17 @@ int ssl3_setup_buffers(SSL *s)
 
 	if (s->s3->wbuf.buf == NULL)
 		{
-		len = SSL3_RT_MAX_PACKET_SIZE;
-		len += headerlen + 256; /* extra space for empty fragment */
+		if (SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS)
+			{
+			len = SSL3_RT_DEFAULT_PACKET_SIZE;
+			}
+		else
+			{
+			len = SSL3_RT_MAX_PACKET_SIZE;
+			}
+		len += SSL3_RT_DEFAULT_WRITE_OVERHEAD; /* extra space for empty
+                                                          fragment, header, MAC
+                                                          and padding */
 		if ((p=OPENSSL_malloc(len)) == NULL)
 			goto err;
 		s->s3->wbuf.buf = p;
diff --git openssl-0.9.8m/ssl/s3_pkt.c openssl-0.9.8m/ssl/s3_pkt.c
index a2ba574..6fe4004 100644
--- openssl-0.9.8m/ssl/s3_pkt.c
+++ openssl-0.9.8m/ssl/s3_pkt.c
@@ -259,7 +259,8 @@ static int ssl3_get_record(SSL *s)
 		extra=SSL3_RT_MAX_EXTRA;
 	else
 		extra=0;
-	if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
+	if (!(SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS) &&
+		extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
 		{
 		/* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 		 * set after ssl3_setup_buffers() was done */
@@ -312,6 +313,21 @@ again:
 			goto f_err;
 			}
 
+		/* If we receive a valid record larger than the current buffer size,
+		 * allocate some memory for it.
+		 */
+		if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
+			{
+			if ((p=OPENSSL_realloc(s->s3->rbuf.buf, rr->length + SSL3_RT_HEADER_LENGTH))==NULL)
+				{
+				SSLerr(SSL_F_SSL3_GET_RECORD,ERR_R_MALLOC_FAILURE);
+				goto err;
+				}
+			s->s3->rbuf.buf=p;
+			s->s3->rbuf.len=rr->length + SSL3_RT_HEADER_LENGTH;
+			s->packet= &(s->s3->rbuf.buf[0]);
+			}
+
 		/* now s->rstate == SSL_ST_READ_BODY */
 		}
 
@@ -525,6 +541,7 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 	const unsigned char *buf=buf_;
 	unsigned int tot,n,nw;
 	int i;
+    unsigned int max_plain_length;
 
 	s->rwstate=SSL_NOTHING;
 	tot=s->s3->wnum;
@@ -544,8 +562,13 @@ int ssl3_write_bytes(SSL *s, int type, c
 	n=(len-tot);
 	for (;;)
 		{
-		if (n > SSL3_RT_MAX_PLAIN_LENGTH)
-			nw=SSL3_RT_MAX_PLAIN_LENGTH;
+		if (type == SSL3_RT_APPLICATION_DATA && (SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS))
+			max_plain_length = SSL3_RT_DEFAULT_PLAIN_LENGTH;
+		else
+			max_plain_length = SSL3_RT_MAX_PLAIN_LENGTH;
+
+		if (n > max_plain_length)
+			nw = max_plain_length;
 		else
 			nw=n;
 
@@ -629,7 +651,9 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 			if (prefix_len <= 0)
 				goto err;
 
-			if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
+			if (s->s3->wbuf.len < (size_t)prefix_len +
+				((SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS) ? SSL3_RT_DEFAULT_PACKET_SIZE :
+					SSL3_RT_MAX_PACKET_SIZE))
 				{
 				/* insufficient space */
 				SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
@@ -640,6 +665,18 @@ static int do_ssl3_write(SSL *s, int typ
 		s->s3->empty_fragment_done = 1;
 		}
 
+	/* resize if necessary to hold the data. */
+	if (len + SSL3_RT_DEFAULT_WRITE_OVERHEAD > wb->len)
+		{
+		if ((p=OPENSSL_realloc(wb->buf, len + SSL3_RT_DEFAULT_WRITE_OVERHEAD))==NULL)
+			{
+			SSLerr(SSL_F_DO_SSL3_WRITE,ERR_R_MALLOC_FAILURE);
+			goto err;
+			}
+		wb->buf = p;
+		wb->len = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD;
+		}
+
 	p = wb->buf + prefix_len;
 
 	/* write the header */
diff --git openssl-0.9.8m/ssl/ssl.h openssl-0.9.8m/ssl/ssl.h
index 47ce1ea..16a90a8 100644
--- openssl-0.9.8m/ssl/ssl.h
+++ openssl-0.9.8m/ssl/ssl.h
@@ -560,7 +560,9 @@ typedef struct ssl_session_st
 #define SSL_MODE_AUTO_RETRY 0x00000004L
 /* Don't attempt to automatically build certificate chain */
 #define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
-
+/* Use small read and write buffers: (a) lazy allocate read buffers for
+ * large incoming records, and (b) limit the size of outgoing records. */
+#define SSL_MODE_SMALL_BUFFERS 0x00000010L
 
 /* Note: SSL[_CTX]_set_{options,mode} use |= op on the previous value,
  * they cannot be used to clear bits. */
diff --git openssl-0.9.8m/ssl/ssl3.h openssl-0.9.8m/ssl/ssl3.h
index 7e6afee..b5b8683 100644
--- openssl-0.9.8m/ssl/ssl3.h
+++ openssl-0.9.8m/ssl/ssl3.h
@@ -256,6 +256,9 @@ extern "C" {
 #define SSL3_RT_MAX_EXTRA			(16384)
 #endif
 
+/* Default buffer length used for writen records.  Thus a generated record
+ * will contain plaintext no larger than this value. */
+#define SSL3_RT_DEFAULT_PLAIN_LENGTH	2048
 #define SSL3_RT_MAX_PLAIN_LENGTH		16384
 #ifdef OPENSSL_NO_COMP
 #define SSL3_RT_MAX_COMPRESSED_LENGTH	SSL3_RT_MAX_PLAIN_LENGTH
@@ -263,6 +266,12 @@ extern "C" {
 #define SSL3_RT_MAX_COMPRESSED_LENGTH	(1024+SSL3_RT_MAX_PLAIN_LENGTH)
 #endif
 #define SSL3_RT_MAX_ENCRYPTED_LENGTH	(1024+SSL3_RT_MAX_COMPRESSED_LENGTH)
+/* Extra space for empty fragment, headers, MAC, and padding. */
+#define SSL3_RT_DEFAULT_WRITE_OVERHEAD  256
+#define SSL3_RT_DEFAULT_PACKET_SIZE     4096 - SSL3_RT_DEFAULT_WRITE_OVERHEAD
+#if SSL3_RT_DEFAULT_PLAIN_LENGTH + SSL3_RT_DEFAULT_WRITE_OVERHEAD > SSL3_RT_DEFAULT_PACKET_SIZE
+#error "Insufficient space allocated for write buffers."
+#endif
 #define SSL3_RT_MAX_PACKET_SIZE		(SSL3_RT_MAX_ENCRYPTED_LENGTH+SSL3_RT_HEADER_LENGTH)
 #define SSL3_RT_MAX_DATA_SIZE			(1024*1024)
 
diff --git openssl-0.9.8m/ssl/ssltest.c openssl-0.9.8m/ssl/ssltest.c
index b09c542..09d3502 100644
--- openssl-0.9.8m/ssl/ssltest.c
+++ openssl-0.9.8m/ssl/ssltest.c
@@ -277,6 +277,8 @@ static void sv_usage(void)
 	               "                 (default is sect163r2).\n");
 #endif
 	fprintf(stderr," -test_cipherlist - verifies the order of the ssl cipher lists\n");
+	fprintf(stderr," -c_small_records - enable client side use of small SSL record buffers\n");
+	fprintf(stderr," -s_small_records - enable server side use of small SSL record buffers\n");
 	}
 
 static void print_details(SSL *c_ssl, const char *prefix)
@@ -431,6 +433,9 @@ int main(int argc, char *argv[])
 #ifdef OPENSSL_FIPS
 	int fips_mode=0;
 #endif
+	int ssl_mode = 0;
+	int c_small_records=0;
+	int s_small_records=0;
 
 	verbose = 0;
 	debug = 0;
@@ -619,6 +624,14 @@ int main(int argc, char *argv[])
 			{
 			test_cipherlist = 1;
 			}
+		else if (strcmp(*argv, "-c_small_records") == 0)
+			{
+			c_small_records = 1;
+			}
+		else if (strcmp(*argv, "-s_small_records") == 0)
+			{
+			s_small_records = 1;
+			}
 		else
 			{
 			fprintf(stderr,"unknown option %s\n",*argv);
@@ -755,6 +768,21 @@ bad:
 		SSL_CTX_set_cipher_list(s_ctx,cipher);
 		}
 
+	ssl_mode = 0;
+	if (c_small_records)
+		{
+		ssl_mode = SSL_CTX_get_mode(c_ctx);
+		ssl_mode |= SSL_MODE_SMALL_BUFFERS;
+		SSL_CTX_set_mode(c_ctx, ssl_mode);
+		}
+	ssl_mode = 0;
+	if (s_small_records)
+		{
+		ssl_mode = SSL_CTX_get_mode(s_ctx);
+		ssl_mode |= SSL_MODE_SMALL_BUFFERS;
+		SSL_CTX_set_mode(s_ctx, ssl_mode);
+		}
+
 #ifndef OPENSSL_NO_DH
 	if (!no_dhe)
 		{
diff --git openssl-0.9.8m/test/testssl openssl-0.9.8m/test/testssl
index 8ac90ae..a9b2e24 100644
--- openssl-0.9.8m/test/testssl
+++ openssl-0.9.8m/test/testssl
@@ -70,6 +70,16 @@ $ssltest -client_auth $CA $extra || exit 1
 echo test sslv2/sslv3 with both client and server authentication
 $ssltest -server_auth -client_auth $CA $extra || exit 1
 
+echo test sslv2/sslv3 with both client and server authentication and small client buffers
+$ssltest -server_auth -client_auth -c_small_records $CA $extra || exit 1
+
+echo test sslv2/sslv3 with both client and server authentication and small server buffers
+$ssltest -server_auth -client_auth -s_small_records $CA $extra || exit 1
+
+echo test sslv2/sslv3 with both client and server authentication and small client and server buffers
+$ssltest -server_auth -client_auth -c_small_records -s_small_records $CA $extra || exit 1
+
+
 echo test sslv2 via BIO pair
 $ssltest -bio_pair -ssl2 $extra || exit 1