commit ed4af8b57cefdf9cf6ce1bfee79f4d1f6139112d
author Manuel Pégourié-Gonnard <mpg@elzevir.fr> Thu Jul 18 14:07:09 2013 +0200
committer Manuel Pégourié-Gonnard <mpg@elzevir.fr> Thu Jul 18 14:07:09 2013 +0200
tree ef49b7ea060d6f8696f0e6ac7c971b63e8da59fb
parent 581e6b6d6cbdc2f913876fd4c0cfb1531da87e66

Move negotiated max fragment length to session

User-set max fragment length remains in ssl_context.
The min of the two is used for sizing fragments.

include/polarssl/ssl.h

diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 5b4e36f..e9e33e3 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -124,6 +124,7 @@
 #define SSL_MAX_FRAG_LEN_1024           2   /*!< MaxFragmentLength 2^10     */
 #define SSL_MAX_FRAG_LEN_2048           3   /*!< MaxFragmentLength 2^11     */
 #define SSL_MAX_FRAG_LEN_4096           4   /*!< MaxFragmentLength 2^12     */
+#define SSL_MAX_FRAG_LEN_INVALID        5   /*!< first invalid value        */
 
 #define SSL_IS_CLIENT                   0
 #define SSL_IS_SERVER                   1
@@ -330,6 +331,8 @@
 #if defined(POLARSSL_X509_PARSE_C)
     x509_cert *peer_cert;       /*!< peer X.509 cert chain */
 #endif /* POLARSSL_X509_PARSE_C */
+
+    unsigned char mfl_code;     /*!< MaxFragmentLength negotiated by peer */
 };
 
 /*
@@ -508,8 +511,7 @@
     size_t out_msglen;          /*!< record header: message length    */
     size_t out_left;            /*!< amount of data not yet written   */
 
-    /* Maximum fragment length extension (RFC 6066 section 4) */
-    unsigned char mfl_code;     /*!< numerical code for MaxFragmentLength   */
+    unsigned char mfl_code;     /*!< MaxFragmentLength chosen by us   */
 
     /*
      * PKI layer

library/ssl_srv.c

diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 2177253..abcc867 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -295,15 +295,14 @@
                                               const unsigned char *buf,
                                               size_t len )
 {
-    int ret;
-
-    if( len != 1 ||
-        ( ret = ssl_set_max_frag_len( ssl, buf[0] ) ) != 0 )
+    if( len != 1 || buf[0] >= SSL_MAX_FRAG_LEN_INVALID )
     {
         SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
         return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
     }
 
+    ssl->session_negotiate->mfl_code = buf[0];
+
     return( 0 );
 }
 
@@ -993,7 +992,7 @@
 {
     unsigned char *p = buf;
 
-    if( ssl->mfl_code == SSL_MAX_FRAG_LEN_NONE ) {
+    if( ssl->session_negotiate->mfl_code == SSL_MAX_FRAG_LEN_NONE ) {
         *olen = 0;
         return;
     }
@@ -1006,7 +1005,7 @@
     *p++ = 0x00;
     *p++ = 1;
 
-    *p++ = ssl->mfl_code;
+    *p++ = ssl->session_negotiate->mfl_code;
 
     *olen = 5;
 }

library/ssl_tls.c

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 0374ee8..a230dc9 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -67,7 +67,7 @@
  *    } MaxFragmentLength;
  * and we add 0 -> extension unused
  */
-static unsigned int mfl_code_to_length[] =
+static unsigned int mfl_code_to_length[SSL_MAX_FRAG_LEN_INVALID] =
 {
     SSL_MAX_CONTENT_LEN,    /* SSL_MAX_FRAG_LEN_NONE */
     512,                    /* SSL_MAX_FRAG_LEN_512  */
@@ -2886,8 +2886,6 @@
     ssl->out_msglen = 0;
     ssl->out_left = 0;
 
-    ssl->mfl_code = SSL_MAX_FRAG_LEN_NONE;
-
     ssl->transform_in = NULL;
     ssl->transform_out = NULL;
 
@@ -3424,6 +3422,15 @@
      */
     max_len = mfl_code_to_length[ssl->mfl_code];
 
+    /*
+     * Check if a smaller max length was negociated
+     */
+    if( ssl->session_out != NULL &&
+        mfl_code_to_length[ssl->session_out->mfl_code] < max_len )
+    {
+        max_len = mfl_code_to_length[ssl->session_out->mfl_code];
+    }
+
     n = ( len < max_len) ? len : max_len;
 
     if( ssl->out_left != 0 )