Free generated supp data after handshake completion, add comment regarding use of num_renegotiations in TLS and supp data generation callbacks

apps/s_client.c

diff --git a/apps/s_client.c b/apps/s_client.c
index b4ea03b..6a4b2da 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -225,8 +225,10 @@
 
 #ifndef OPENSSL_NO_TLSEXT
 
-static const unsigned char *most_recent_supplemental_data;
-static size_t most_recent_supplemental_data_length;
+static unsigned char *generated_supp_data = NULL;
+
+static unsigned char *most_recent_supplemental_data = NULL;
+static size_t most_recent_supplemental_data_length = 0;
 
 static int server_provided_server_authz = 0;
 static int server_provided_client_authz = 0;
@@ -1779,6 +1781,13 @@
 						"CONNECTION ESTABLISHED\n");
 					print_ssl_summary(bio_err, con);
 					}
+				/*handshake is complete - free the generated supp data allocated in the callback */
+				if (generated_supp_data)
+					{
+					OPENSSL_free(generated_supp_data);
+					generated_supp_data = NULL;
+					}
+
 				print_stuff(bio_c_out,con,full_log);
 				if (full_log > 0) full_log--;
 
@@ -2450,6 +2459,8 @@
 	{
 	if (c_auth)
 		{
+		/*if auth_require_reneg flag is set, only send extensions if
+		  renegotiation has occurred */
 		if (!c_auth_require_reneg || (c_auth_require_reneg && SSL_num_renegotiations(s)))
 			{
 			*out = auth_ext_data;
@@ -2478,15 +2489,16 @@
 				     const unsigned char **out,
 				     unsigned short *outlen, void *arg)
 	{
-	unsigned char *result;
 	if (c_auth && server_provided_client_authz && server_provided_server_authz)
 		{
+		/*if auth_require_reneg flag is set, only send supplemental data if
+		  renegotiation has occurred */
 		if (!c_auth_require_reneg
 		    || (c_auth_require_reneg && SSL_num_renegotiations(s)))
 			{
-			result = OPENSSL_malloc(10);
-			memcpy(result, "5432154321", 10);
-			*out = result;
+			generated_supp_data = OPENSSL_malloc(10);
+			memcpy(generated_supp_data, "5432154321", 10);
+			*out = generated_supp_data;
 			*outlen = 10;
 			return 1;
 			}

apps/s_server.c

diff --git a/apps/s_server.c b/apps/s_server.c
index 29189fd..44acb1e 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -229,8 +229,10 @@
 
 static const unsigned char auth_ext_data[]={TLSEXT_AUTHZDATAFORMAT_dtcp};
 
-static const unsigned char *most_recent_supplemental_data;
-static size_t most_recent_supplemental_data_length;
+static unsigned char *generated_supp_data = NULL;
+
+static unsigned char *most_recent_supplemental_data = NULL;
+static size_t most_recent_supplemental_data_length = 0;
 
 static int client_provided_server_authz = 0;
 static int client_provided_client_authz = 0;
@@ -2673,6 +2675,13 @@
 			i=SSL_accept(con);
 		}
 #endif
+	/*handshake is complete - free the generated supp data allocated in the callback */
+	if (generated_supp_data)
+		{
+        OPENSSL_free(generated_supp_data);
+		generated_supp_data = NULL;
+		}
+
 	if (i <= 0)
 		{
 		if (BIO_sock_should_retry(i))
@@ -3583,6 +3592,8 @@
 	{
 	if (c_auth && client_provided_client_authz && client_provided_server_authz)
 		{
+		/*if auth_require_reneg flag is set, only send extensions if
+		  renegotiation has occurred */
 		if (!c_auth_require_reneg
 		    || (c_auth_require_reneg && SSL_num_renegotiations(s)))
 			{
@@ -3612,15 +3623,16 @@
 				     const unsigned char **out,
 				     unsigned short *outlen, void *arg)
 	{
-	unsigned char *result;
 	if (c_auth && client_provided_client_authz && client_provided_server_authz)
 		{
+		/*if auth_require_reneg flag is set, only send supplemental data if
+		  renegotiation has occurred */
 		if (!c_auth_require_reneg
 		    || (c_auth_require_reneg && SSL_num_renegotiations(s)))
 			{
-			result = OPENSSL_malloc(10);
-			memcpy(result, "1234512345", 10);
-			*out = result;
+			generated_supp_data = OPENSSL_malloc(10);
+			memcpy(generated_supp_data, "1234512345", 10);
+			*out = generated_supp_data;
 			*outlen = 10;
 			return 1;
 			}