Commit 68db4dda authored by Matt Caswell's avatar Matt Caswell
Browse files

Add an extension initilisation and finalisation capability 



Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent ab83e314

ssl/statem/extensions.c

+77 −2
Original line number Diff line number Diff line
@@ -14,6 +14,11 @@ 
typedef struct {

    /* The ID for the extension */

    unsigned int type;

    /*

     * Initialise extension before parsing. Always called even if extension not

     * present

     */

    int (*init_ext)(SSL *s, unsigned int context);

    /* Parse extension received by server from client */

    int (*parse_client_ext)(SSL *s, PACKET *pkt, int *al);

    /* Parse extension received by client from server */
@@ -22,6 +27,11 @@ typedef struct { 
    int (*construct_server_ext)(SSL *s, WPACKET *pkt, int *al);

    /* Construct extension sent by client */

    int (*construct_client_ext)(SSL *s, WPACKET *pkt, int *al);

    /*

     * Finalise extension after parsing. Always called even if extension not

     * present

     */

    int (*finalise_ext)(SSL *s, unsigned int context);

    unsigned int context;

} EXTENSION_DEFINITION;
@@ -33,74 +43,89 @@ typedef struct { 
static const EXTENSION_DEFINITION ext_defs[] = {

    {

        TLSEXT_TYPE_renegotiate,

        NULL,

        tls_parse_client_renegotiate,

        tls_parse_server_renegotiate,

        tls_construct_server_renegotiate,

        tls_construct_client_renegotiate,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED

        | EXT_TLS1_2_AND_BELOW_ONLY

    },

    {

        TLSEXT_TYPE_server_name,

        NULL,

        tls_parse_client_server_name,

        tls_parse_server_server_name,

        tls_construct_server_server_name,

        tls_construct_client_server_name,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO

        | EXT_TLS1_3_ENCRYPTED_EXTENSIONS

    },

#ifndef OPENSSL_NO_SRP

    {

        TLSEXT_TYPE_srp,

        NULL,

        tls_parse_client_srp,

        NULL,

        NULL,

        tls_construct_client_srp,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

#endif

#ifndef OPENSSL_NO_EC

    {

        TLSEXT_TYPE_ec_point_formats,

        NULL,

        tls_parse_client_ec_pt_formats,

        tls_parse_server_ec_pt_formats,

        tls_construct_server_ec_pt_formats,

        tls_construct_client_ec_pt_formats,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

    {

        TLSEXT_TYPE_supported_groups,

        NULL,

        tls_parse_client_supported_groups,

        NULL,

        NULL /* TODO(TLS1.3): Need to add this */,

        tls_construct_client_supported_groups,

        EXT_CLIENT_HELLO

        | EXT_TLS1_3_ENCRYPTED_EXTENSIONS

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS

    },

#endif

    {

        TLSEXT_TYPE_session_ticket,

        NULL,

        tls_parse_client_session_ticket,

        tls_parse_server_session_ticket,

        tls_construct_server_session_ticket,

        tls_construct_client_session_ticket,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

    {

        TLSEXT_TYPE_signature_algorithms,

        NULL,

        tls_parse_client_sig_algs,

        NULL,

        NULL,

        tls_construct_client_sig_algs,

        NULL,

        EXT_CLIENT_HELLO

    },

#ifndef OPENSSL_NO_OCSP

    {

        TLSEXT_TYPE_status_request,

        NULL,

        tls_parse_client_status_request,

        tls_parse_server_status_request,

        tls_construct_server_status_request,

        tls_construct_client_status_request,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO

        | EXT_TLS1_3_CERTIFICATE

    },
@@ -108,44 +133,53 @@ static const EXTENSION_DEFINITION ext_defs[] = { 
#ifndef OPENSSL_NO_NEXTPROTONEG

    {

        TLSEXT_TYPE_next_proto_neg,

        NULL,

        tls_parse_client_npn,

        tls_parse_server_npn,

        tls_construct_server_next_proto_neg,

        tls_construct_client_npn,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

#endif

    {

        TLSEXT_TYPE_application_layer_protocol_negotiation,

        NULL,

        tls_parse_client_alpn,

        tls_parse_server_alpn,

        tls_construct_server_alpn,

        tls_construct_client_alpn,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO

        | EXT_TLS1_3_ENCRYPTED_EXTENSIONS

    },

#ifndef OPENSSL_NO_SRTP

    {

        TLSEXT_TYPE_use_srtp,

        NULL,

        tls_parse_client_use_srtp,

        tls_parse_server_use_srtp,

        tls_construct_server_use_srtp,

        tls_construct_client_use_srtp,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO

        | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY

    },

#endif

    {

        TLSEXT_TYPE_encrypt_then_mac,

        NULL,

        tls_parse_client_etm,

        tls_parse_server_etm,

        tls_construct_server_etm,

        tls_construct_client_etm,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

#ifndef OPENSSL_NO_CT

    {

        TLSEXT_TYPE_signed_certificate_timestamp,

        NULL,

        /*

         * No server side support for this, but can be provided by a custom

         * extension. This is an exception to the rule that custom extensions
@@ -155,33 +189,40 @@ static const EXTENSION_DEFINITION ext_defs[] = { 
        tls_parse_server_sct,

        NULL,

        tls_construct_client_sct,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO

        | EXT_TLS1_3_CERTIFICATE

    },

#endif

    {

        TLSEXT_TYPE_extended_master_secret,

        NULL,

        tls_parse_client_ems,

        tls_parse_server_ems,

        tls_construct_server_ems,

        tls_construct_client_ems,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

    {

        TLSEXT_TYPE_supported_versions,

        NULL,

        /* Processed inline as part of version selection */

        NULL,

        NULL,

        NULL,

        tls_construct_client_supported_versions,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY

    },

    {

        TLSEXT_TYPE_key_share,

        NULL,

        tls_parse_client_key_share,

        tls_parse_server_key_share,

        tls_construct_server_key_share,

        tls_construct_client_key_share,

        NULL,

        EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO

        | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY

        | EXT_TLS1_3_ONLY
@@ -194,18 +235,22 @@ static const EXTENSION_DEFINITION ext_defs[] = { 
        TLSEXT_TYPE_cryptopro_bug,

        NULL,

        NULL,

        NULL,

        tls_construct_server_cryptopro_bug,

        NULL,

        NULL,

        EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY

    },

    {

        /* Last in the list because it must be added as the last extension */

        TLSEXT_TYPE_padding,

        NULL,

        /* We send this, but don't read it */

        NULL,

        NULL,

        NULL,

        tls_construct_client_padding,

        NULL,

        EXT_CLIENT_HELLO

    }

};
@@ -362,6 +407,18 @@ int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, 
        }

    }



    /*

     * Initialise all known extensions relevant to this context, whether we have

     * found them or not

     */

    for (i = 0; i < OSSL_NELEM(ext_defs); i++) {

        if(ext_defs[i].init_ext != NULL && (ext_defs[i].context & context) != 0

                && !ext_defs[i].init_ext(s, context)) {

            *ad = SSL_AD_INTERNAL_ERROR;

            goto err;

        }

    }



    *res = raw_extensions;

    *numfound = num_extensions;

    return 1;
@@ -371,6 +428,11 @@ int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, 
    return 0;

}



/*

 * Parse all remaining extensions that have not yet been parsed. Also calls the

 * finalisation for all extensions at the end. Returns 1 for success or 0 for

 * failure. On failure, |*al| is populated with a suitable alert code.

 */

int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts,

                             size_t numexts, int *al)

{
@@ -435,6 +497,19 @@ int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, 
            return 0;

    }



    /*

     * Finalise all known extensions relevant to this context, whether we have

     * found them or not

     */

    for (loop = 0; loop < OSSL_NELEM(ext_defs); loop++) {

        if(ext_defs[loop].finalise_ext != NULL

                && (ext_defs[loop].context & context) != 0

                && !ext_defs[loop].finalise_ext(s, context)) {

            *al = SSL_AD_INTERNAL_ERROR;

            return 0;

        }

    }



    return 1;

}