1 files changed, 35 insertions, 24 deletions

diff --git a/src/libtls/tls_eap.c b/src/libtls/tls_eap.c
index 685904fdf..928aadcb3 100644
--- a/src/libtls/tls_eap.c
+++ b/src/libtls/tls_eap.c
@@ -21,8 +21,11 @@
 #include <debug.h>
 #include <library.h>
 
-/** Size limit for a single TLS message */
-#define MAX_TLS_MESSAGE_LEN 65536
+/**
+ * Size limit for a TLS message allowing for worst-case protection overhead
+ * according to section 6.2.3. "Payload Protection" of RFC 5246 TLS 1.2
+ */
+#define TLS_MAX_MESSAGE_LEN		4 * (TLS_MAX_FRAGMENT_LEN + 2048)
 
 typedef struct private_tls_eap_t private_tls_eap_t;
 
@@ -79,7 +82,7 @@ struct private_tls_eap_t {
 	int processed;
 
 	/**
-	 * Maximum number of processed EAP messages/fragments 
+	 * Maximum number of processed EAP messages/fragments
 	 */
 	int max_msg_count;
 };
@@ -138,7 +141,7 @@ METHOD(tls_eap_t, initiate, status_t,
 
 		*out = chunk_clone(chunk_from_thing(pkt));
 		DBG2(DBG_TLS, "sending %N start packet (%u bytes)",
-					   eap_type_names, this->type, sizeof(eap_tls_packet_t));
+			 eap_type_names, this->type, sizeof(eap_tls_packet_t));
 		DBG3(DBG_TLS, "%B", out);
 		return NEED_MORE;
 	}
@@ -150,10 +153,12 @@ METHOD(tls_eap_t, initiate, status_t,
  */
 static status_t process_pkt(private_tls_eap_t *this, eap_tls_packet_t *pkt)
 {
-	u_int32_t msg_len;
 	u_int16_t pkt_len;
+	u_int32_t msg_len;
+	size_t msg_len_offset = 0;
 
 	pkt_len = untoh16(&pkt->length);
+
 	if (pkt->flags & EAP_TLS_LENGTH)
 	{
 		if (pkt_len < sizeof(eap_tls_packet_t) + sizeof(msg_len))
@@ -163,16 +168,17 @@ static status_t process_pkt(private_tls_eap_t *this, eap_tls_packet_t *pkt)
 		}
 		msg_len = untoh32(pkt + 1);
 		if (msg_len < pkt_len - sizeof(eap_tls_packet_t) - sizeof(msg_len) ||
-			msg_len > MAX_TLS_MESSAGE_LEN)
+			msg_len > TLS_MAX_MESSAGE_LEN)
 		{
-			DBG1(DBG_TLS, "invalid %N packet length", eap_type_names, this->type);
+			DBG1(DBG_TLS, "invalid %N packet length (%u bytes)", eap_type_names,
+				 this->type, msg_len);
 			return FAILED;
 		}
-		return this->tls->process(this->tls, (char*)(pkt + 1) + sizeof(msg_len),
-						pkt_len - sizeof(eap_tls_packet_t) - sizeof(msg_len));
+		msg_len_offset = sizeof(msg_len);
 	}
-	return this->tls->process(this->tls, (char*)(pkt + 1),
-							  pkt_len - sizeof(eap_tls_packet_t));
+
+	return this->tls->process(this->tls, (char*)(pkt + 1) + msg_len_offset,
+					   pkt_len - sizeof(eap_tls_packet_t) - msg_len_offset);
 }
 
 /**
@@ -182,7 +188,7 @@ static status_t build_pkt(private_tls_eap_t *this, chunk_t *out)
 {
 	char buf[this->frag_size];
 	eap_tls_packet_t *pkt;
-	size_t len, reclen;
+	size_t len, reclen, msg_len_offset;
 	status_t status;
 	char *kind;
 
@@ -214,15 +220,16 @@ static status_t build_pkt(private_tls_eap_t *this, chunk_t *out)
 	if (this->first_fragment)
 	{
 		len = sizeof(buf) - sizeof(eap_tls_packet_t) - sizeof(u_int32_t);
-		status = this->tls->build(this->tls, buf + sizeof(eap_tls_packet_t) +
-								  sizeof(u_int32_t), &len, &reclen);
+		msg_len_offset = sizeof(u_int32_t);
 	}
 	else
 	{
 		len = sizeof(buf) - sizeof(eap_tls_packet_t);
-		status = this->tls->build(this->tls, buf + sizeof(eap_tls_packet_t),
-								  &len, &reclen);
+		msg_len_offset = 0;
 	}
+	status = this->tls->build(this->tls, buf + sizeof(eap_tls_packet_t) +
+										 msg_len_offset, &len, &reclen);
+
 	switch (status)
 	{
 		case NEED_MORE:
@@ -230,7 +237,7 @@ static status_t build_pkt(private_tls_eap_t *this, chunk_t *out)
 			kind = "further fragment";
 			if (this->first_fragment)
 			{
-		        pkt->flags |= EAP_TLS_LENGTH;
+				pkt->flags |= EAP_TLS_LENGTH;
 				this->first_fragment = FALSE;
 				kind = "first fragment";
 			}
@@ -244,11 +251,15 @@ static status_t build_pkt(private_tls_eap_t *this, chunk_t *out)
 				}
 				kind = "packet";
 			}
-			else
+			else if (this->type != EAP_TNC)
 			{
 				this->first_fragment = TRUE;
 				kind = "final fragment";
 			}
+			else
+			{
+				kind = "packet";
+			}
 			break;
 		default:
 			return status;
@@ -256,7 +267,7 @@ static status_t build_pkt(private_tls_eap_t *this, chunk_t *out)
 	if (reclen)
 	{
 		if (pkt->flags & EAP_TLS_LENGTH)
-		{ 
+		{
 			htoun32(pkt + 1, reclen);
 			len += sizeof(u_int32_t);
 			pkt->flags |= EAP_TLS_LENGTH;
@@ -264,15 +275,15 @@ static status_t build_pkt(private_tls_eap_t *this, chunk_t *out)
 		else
 		{
 			/* get rid of the reserved length field */
-			memcpy(buf+sizeof(eap_packet_t),
-				   buf+sizeof(eap_packet_t)+sizeof(u_int32_t), len);	
+			memmove(buf + sizeof(eap_tls_packet_t),
+					buf + sizeof(eap_tls_packet_t) + sizeof(u_int32_t), len);
 		}
 	}
 	len += sizeof(eap_tls_packet_t);
 	htoun16(&pkt->length, len);
 	*out = chunk_clone(chunk_create(buf, len));
 	DBG2(DBG_TLS, "sending %N %s (%u bytes)",
-				   eap_type_names, this->type, kind, len);
+		 eap_type_names, this->type, kind, len);
 	DBG3(DBG_TLS, "%B", out);
 	return NEED_MORE;
 }
@@ -319,7 +330,7 @@ METHOD(tls_eap_t, process, status_t,
 	eap_tls_packet_t *pkt;
 	status_t status;
 
-	if (++this->processed > this->max_msg_count)
+	if (this->max_msg_count && ++this->processed > this->max_msg_count)
 	{
 		DBG1(DBG_TLS, "%N packet count exceeded (%d > %d)",
 			 eap_type_names, this->type,
@@ -441,7 +452,7 @@ tls_eap_t *tls_eap_create(eap_type_t type, tls_t *tls, size_t frag_size,
 		},
 		.type = type,
 		.is_server = tls->is_server(tls),
-		.first_fragment = TRUE,
+		.first_fragment = (type != EAP_TNC),
 		.frag_size = frag_size,
 		.max_msg_count = max_msg_count,
 		.include_length = include_length,