+#ifdef TLSEXT_TYPE_padding
+ /* Add padding to workaround bugs in F5 terminators.
+ * See https://tools.ietf.org/html/draft-agl-tls-padding-03
+ *
+ * NB: because this code works out the length of all existing
+ * extensions it MUST always appear last.
+ */
+ {
+ int hlen = ret - (unsigned char *)s->init_buf->data;
+ /* The code in s23_clnt.c to build ClientHello messages includes the
+ * 5-byte record header in the buffer, while the code in s3_clnt.c does
+ * not. */
+ if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
+ hlen -= 5;
+ if (hlen > 0xff && hlen < 0x200)
+ {
+ hlen = 0x200 - hlen;
+ if (hlen >= 4)
+ hlen -= 4;
+ else
+ hlen = 0;
+
+ s2n(TLSEXT_TYPE_padding, ret);
+ s2n(hlen, ret);
+ memset(ret, 0, hlen);
+ ret += hlen;
+ }
+ }
+#endif
+