Move length check earlier to ensure we don't go beyond the end of the user's buffer...

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index 0d3f47780a116a95528b7614b044e809b5e5b22e..8a23de5f34cbb7b9ddeb77208416a29009cf15cf 100644 (file)
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -619,6 +619,21 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
                        }
                }
 
+       /* ensure that if we end up with a smaller value of data to write 
+        * out than the the original len from a write which didn't complete 
+        * for non-blocking I/O and also somehow ended up avoiding 
+        * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as
+        * it must never be possible to end up with (len-tot) as a large
+        * number that will then promptly send beyond the end of the users
+        * buffer ... so we trap and report the error in a way the user
+        * will notice
+        */
+       if ( len < tot)
+               {
+               SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH);
+               return(-1);
+               }
+
        /* first check if there is a SSL3_BUFFER still being written
         * out.  This will happen with non blocking IO */
        if (wb->left != 0)
@@ -777,20 +792,6 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
                return tot;
                }
 
-       /* ensure that if we end up with a smaller value of data to write 
-        * out than the the original len from a write which didn't complete 
-        * for non-blocking I/O and also somehow ended up avoiding 
-        * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as
-        * it must never be possible to end up with (len-tot) as a large
-        * number that will then promptly send beyond the end of the users
-        * buffer ... so we trap and report the error in a way the user
-        * will notice
-        */
-       if ( len < tot)
-               {
-               SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH);
-               return(-1);
-               }
 
        n=(len-tot);
        for (;;)