Commit dc5744cb authored by Emilia Kasper's avatar Emilia Kasper
Browse files

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: default avatarRich Salz <rsalz@openssl.org>
parent 0c20802c

CHANGES

+6 −0
Original line number Diff line number Diff line
@@ -4,6 +4,12 @@ 


 Changes between 1.0.2f and 1.1.0  [xx XXX xxxx]



  *) 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.

     [Emilia Käsper]



  *) The signature of the session callback configured with

     SSL_CTX_sess_set_get_cb was changed. The read-only input buffer

     was explicitly marked as 'const unsigned char*' instead of

apps/apps.h

+3 −3
Original line number Diff line number Diff line
@@ -285,7 +285,7 @@ void wait_for_async(SSL *s); 
# define OPT_S_ENUM \

        OPT_S__FIRST=3000, \

        OPT_S_NOSSL3, OPT_S_NOTLS1, OPT_S_NOTLS1_1, OPT_S_NOTLS1_2, \

        OPT_S_BUGS, OPT_S_NOCOMP, OPT_S_ECDHSINGLE, OPT_S_NOTICKET, \

        OPT_S_BUGS, OPT_S_COMP, OPT_S_ECDHSINGLE, OPT_S_NOTICKET, \

        OPT_S_SERVERPREF, OPT_S_LEGACYRENEG, OPT_S_LEGACYCONN, \

        OPT_S_ONRESUMP, OPT_S_NOLEGACYCONN, OPT_S_STRICT, OPT_S_SIGALGS, \

        OPT_S_CLIENTSIGALGS, OPT_S_CURVES, OPT_S_NAMEDCURVE, OPT_S_CIPHER, \
@@ -298,7 +298,7 @@ void wait_for_async(SSL *s); 
        {"no_tls1_1", OPT_S_NOTLS1_1, '-' }, \

        {"no_tls1_2", OPT_S_NOTLS1_2, '-' }, \

        {"bugs", OPT_S_BUGS, '-' }, \

        {"no_comp", OPT_S_NOCOMP, '-', "Don't use SSL/TLS-level compression" }, \

        {"comp", OPT_S_COMP, '-', "Use SSL/TLS-level compression" }, \

        {"ecdh_single", OPT_S_ECDHSINGLE, '-' }, \

        {"no_ticket", OPT_S_NOTICKET, '-' }, \

        {"serverpref", OPT_S_SERVERPREF, '-' }, \
@@ -327,7 +327,7 @@ void wait_for_async(SSL *s); 
        case OPT_S_NOTLS1_1: \

        case OPT_S_NOTLS1_2: \

        case OPT_S_BUGS: \

        case OPT_S_NOCOMP: \

        case OPT_S_COMP: \

        case OPT_S_ECDHSINGLE: \

        case OPT_S_NOTICKET: \

        case OPT_S_SERVERPREF: \

doc/ssl/SSL_CONF_cmd.pod

+6 −2
Original line number Diff line number Diff line
@@ -131,9 +131,9 @@ These options are deprecated, instead use B<-min_protocol> and B<-max_protocol>. 


Various bug workarounds are set, same as setting B<SSL_OP_ALL>.



=item B<-no_comp>

=item B<-comp>



Disables support for SSL/TLS compression, same as setting B<SSL_OP_NO_COMPRESS>.

Enables support for SSL/TLS compression, same as clearing B<SSL_OP_NO_COMPRESSION>.



=item B<-no_ticket>
@@ -495,6 +495,10 @@ Disable TLS session tickets: 


 SSL_CONF_cmd(ctx, "Options", "-SessionTicket");



Enable compression:



 SSL_CONF_cmd(ctx, "Options", "Compression");



Set supported curves to P-256, P-384:



 SSL_CONF_cmd(ctx, "Curves", "P-256:P-384");

ssl/ssl_conf.c

+2 −2
Original line number Diff line number Diff line
@@ -581,7 +581,7 @@ static const ssl_conf_cmd_tbl ssl_conf_cmds[] = { 
    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 @@ static const ssl_switch_tbl ssl_cmd_switches[] = { 
    {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 */

ssl/ssl_lib.c

+7 −0
Original line number Diff line number Diff line
@@ -2362,6 +2362,13 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth) 
     * deployed might change this.

     */

    ret->options |= SSL_OP_LEGACY_SERVER_CONNECT;

    /*

     * Disable compression by default to prevent CRIME. Applications can

     * re-enable compression by configuring

     * SSL_CTX_clear_options(ctx, SSL_OP_NO_COMPRESSION);

     * or by using the SSL_CONF library.

     */

    ret->options |= SSL_OP_NO_COMPRESSION;



    return (ret);

 err: