RT3234: disable compression

CRIME protection: disable compression by default, even if OpenSSL is
compiled with zlib enabled. Applications can still enable compression by
calling SSL_CTX_clear_options(ctx, SSL_OP_NO_COMPRESSION), or by using
the SSL_CONF library to configure compression. SSL_CONF continues to
work as before:

SSL_CONF_cmd(ctx, "Options", "Compression") enables compression.

SSL_CONF_cmd(ctx, "Options", "-Compression") disables compression (now
no-op by default).

The command-line switch has changed from -no_comp to -comp.

Reviewed-by: Rich Salz <rsalz@openssl.org>

ssl/ssl_conf.c

diff --git a/ssl/ssl_conf.c b/ssl/ssl_conf.c
index 2c40df1..d0935cf 100644
--- a/ssl/ssl_conf.c
+++ b/ssl/ssl_conf.c
@@ -581,7 +581,7 @@
     SSL_CONF_CMD_SWITCH("no_tls1_1", 0),
     SSL_CONF_CMD_SWITCH("no_tls1_2", 0),
     SSL_CONF_CMD_SWITCH("bugs", 0),
-    SSL_CONF_CMD_SWITCH("no_comp", 0),
+    SSL_CONF_CMD_SWITCH("comp", 0),
     SSL_CONF_CMD_SWITCH("ecdh_single", SSL_CONF_FLAG_SERVER),
     SSL_CONF_CMD_SWITCH("no_ticket", 0),
     SSL_CONF_CMD_SWITCH("serverpref", SSL_CONF_FLAG_SERVER),
@@ -640,7 +640,7 @@
     {SSL_OP_NO_TLSv1_1, 0},     /* no_tls1_1 */
     {SSL_OP_NO_TLSv1_2, 0},     /* no_tls1_2 */
     {SSL_OP_ALL, 0},            /* bugs */
-    {SSL_OP_NO_COMPRESSION, 0}, /* no_comp */
+    {SSL_OP_NO_COMPRESSION, 1}, /* comp */
     {SSL_OP_SINGLE_ECDH_USE, 0}, /* ecdh_single */
     {SSL_OP_NO_TICKET, 0},      /* no_ticket */
     {SSL_OP_CIPHER_SERVER_PREFERENCE, 0}, /* serverpref */