Commit ddc06b35 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Extended master secret extension support. 



Add and retrieve extended master secret extension, setting the flag
SSL_SESS_FLAG_EXTMS appropriately.

Note: this just sets the flag and doesn't include the changes to
master secret generation.
Reviewed-by: default avatarTim Hudson <tjh@openssl.org>
Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
parent c660ec63

ssl/ssl_txt.c

+4 −0
Original line number Diff line number Diff line
@@ -244,6 +244,10 @@ int SSL_SESSION_print(BIO *bp, const SSL_SESSION *x) 
                   X509_verify_cert_error_string(x->verify_result)) <= 0)

        goto err;



    if (BIO_printf(bp, "    Extended master secret: %s\n",

                   x->flags & SSL_SESS_FLAG_EXTMS ? "yes" : "no") <= 0)

        goto err;



    return (1);

 err:

    return (0);

ssl/t1_lib.c

+14 −0
Original line number Diff line number Diff line
@@ -1445,6 +1445,8 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, 
    s2n(TLSEXT_TYPE_encrypt_then_mac, ret);

    s2n(0, ret);

# endif

    s2n(TLSEXT_TYPE_extended_master_secret, ret);

    s2n(0, ret);



    /*

     * Add padding to workaround bugs in F5 terminators. See
@@ -1682,6 +1684,10 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, 
        }

    }

# endif

    if (!s->hit && s->session->flags & SSL_SESS_FLAG_EXTMS) {

        s2n(TLSEXT_TYPE_extended_master_secret, ret);

        s2n(0, ret);

    }



    if (s->s3->alpn_selected) {

        const unsigned char *selected = s->s3->alpn_selected;
@@ -2300,6 +2306,10 @@ static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, 
        else if (type == TLSEXT_TYPE_encrypt_then_mac)

            s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;

# endif

        else if (type == TLSEXT_TYPE_extended_master_secret) {

            if (!s->hit)

                s->session->flags |= SSL_SESS_FLAG_EXTMS;

        }

        /*

         * If this ClientHello extension was unhandled and this is a

         * nonresumed connection, check whether the extension is a custom
@@ -2594,6 +2604,10 @@ static int ssl_scan_serverhello_tlsext(SSL *s, unsigned char **p, 
                s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;

        }

# endif

        else if (type == TLSEXT_TYPE_extended_master_secret) {

            if (!s->hit)

                s->session->flags |= SSL_SESS_FLAG_EXTMS;

        }

        /*

         * If this extension type was not otherwise handled, but matches a

         * custom_cli_ext_record, then send it to the c callback

ssl/t1_trce.c

+2 −1
Original line number Diff line number Diff line
@@ -363,7 +363,8 @@ static ssl_trace_tbl ssl_exts_tbl[] = { 
    {TLSEXT_TYPE_session_ticket, "session_ticket"},

    {TLSEXT_TYPE_renegotiate, "renegotiate"},

    {TLSEXT_TYPE_next_proto_neg, "next_proto_neg"},

    {TLSEXT_TYPE_padding, "padding"}

    {TLSEXT_TYPE_padding, "padding"},

    {TLSEXT_TYPE_extended_master_secret, "extended_master_secret"}

};



static ssl_trace_tbl ssl_curve_tbl[] = {

ssl/tls1.h

+6 −0
Original line number Diff line number Diff line
@@ -250,6 +250,12 @@ extern "C" { 
 * http://www.ietf.org/id/draft-ietf-tls-encrypt-then-mac-02.txt

 */

# define TLSEXT_TYPE_encrypt_then_mac    22

/*

 * Extended master secret extension.

 * http://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml

 * https://tools.ietf.org/id/draft-ietf-tls-session-hash-03.txt

 */

# define TLSEXT_TYPE_extended_master_secret      23



/* ExtensionType value from RFC4507 */

# define TLSEXT_TYPE_session_ticket              35