Commit 25670f3e authored by Matt Caswell's avatar Matt Caswell
Browse files

Split extensions code into core extensions and server extensions code



Later we will have client extensions code too.

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 4b299b8e
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+2 −1
Original line number Diff line number Diff line
@@ -2,7 +2,8 @@ LIBS=../libssl
SOURCE[../libssl]=\
        pqueue.c packet.c \
        statem/statem_srvr.c statem/statem_clnt.c  s3_lib.c  s3_enc.c record/rec_layer_s3.c \
        statem/statem_lib.c statem/extensions.c s3_cbc.c s3_msg.c \
        statem/statem_lib.c statem/extensions.c statem/extensions_srvr.c \
        s3_cbc.c s3_msg.c \
        methods.c   t1_lib.c  t1_enc.c tls13_enc.c t1_ext.c \
        d1_lib.c  record/rec_layer_d1.c d1_msg.c \
        statem/statem_dtls.c d1_srtp.c \
+0 −661
Original line number Diff line number Diff line
@@ -8,33 +8,9 @@
 */

#include <stdlib.h>
#include <openssl/ocsp.h>
#include "../ssl_locl.h"
#include "statem_locl.h"

static int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRP
static int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al);
#endif
#ifndef OPENSSL_NO_EC
static int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al);
#endif
static int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_NEXTPROTONEG
static int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al);
#endif
static int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRTP
static int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al);
#endif
static int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al);

typedef struct {
    /* The ID for the extension */
    unsigned int type;
@@ -535,640 +511,3 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,

    return 1;
}

/*
 * Parse the client's renegotiation binding and abort if it's not right
 */
static int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al)
{
    unsigned int ilen;
    const unsigned char *data;

    /* Parse the length byte */
    if (!PACKET_get_1(pkt, &ilen)
        || !PACKET_get_bytes(pkt, &data, ilen)) {
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
               SSL_R_RENEGOTIATION_ENCODING_ERR);
        *al = SSL_AD_ILLEGAL_PARAMETER;
        return 0;
    }

    /* Check that the extension matches */
    if (ilen != s->s3->previous_client_finished_len) {
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
               SSL_R_RENEGOTIATION_MISMATCH);
        *al = SSL_AD_HANDSHAKE_FAILURE;
        return 0;
    }

    if (memcmp(data, s->s3->previous_client_finished,
               s->s3->previous_client_finished_len)) {
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
               SSL_R_RENEGOTIATION_MISMATCH);
        *al = SSL_AD_HANDSHAKE_FAILURE;
        return 0;
    }

    s->s3->send_connection_binding = 1;

    return 1;
}

static int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al)
{
    unsigned int servname_type;
    PACKET sni, hostname;

    /*-
     * The servername extension is treated as follows:
     *
     * - Only the hostname type is supported with a maximum length of 255.
     * - The servername is rejected if too long or if it contains zeros,
     *   in which case an fatal alert is generated.
     * - The servername field is maintained together with the session cache.
     * - When a session is resumed, the servername call back invoked in order
     *   to allow the application to position itself to the right context.
     * - The servername is acknowledged if it is new for a session or when
     *   it is identical to a previously used for the same session.
     *   Applications can control the behaviour.  They can at any time
     *   set a 'desirable' servername for a new SSL object. This can be the
     *   case for example with HTTPS when a Host: header field is received and
     *   a renegotiation is requested. In this case, a possible servername
     *   presented in the new client hello is only acknowledged if it matches
     *   the value of the Host: field.
     * - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
     *   if they provide for changing an explicit servername context for the
     *   session, i.e. when the session has been established with a servername
     *   extension.
     * - On session reconnect, the servername extension may be absent.
     *
     */
    if (!PACKET_as_length_prefixed_2(pkt, &sni)
        /* ServerNameList must be at least 1 byte long. */
        || PACKET_remaining(&sni) == 0) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    /*
     * Although the server_name extension was intended to be
     * extensible to new name types, RFC 4366 defined the
     * syntax inextensibility and OpenSSL 1.0.x parses it as
     * such.
     * RFC 6066 corrected the mistake but adding new name types
     * is nevertheless no longer feasible, so act as if no other
     * SNI types can exist, to simplify parsing.
     *
     * Also note that the RFC permits only one SNI value per type,
     * i.e., we can only have a single hostname.
     */
    if (!PACKET_get_1(&sni, &servname_type)
        || servname_type != TLSEXT_NAMETYPE_host_name
        || !PACKET_as_length_prefixed_2(&sni, &hostname)) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    if (!s->hit) {
        if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
            *al = TLS1_AD_UNRECOGNIZED_NAME;
            return 0;
        }

        if (PACKET_contains_zero_byte(&hostname)) {
            *al = TLS1_AD_UNRECOGNIZED_NAME;
            return 0;
        }

        if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) {
            *al = TLS1_AD_INTERNAL_ERROR;
            return 0;
        }

        s->servername_done = 1;
    } else {
        /*
         * TODO(openssl-team): if the SNI doesn't match, we MUST
         * fall back to a full handshake.
         */
        s->servername_done = s->session->tlsext_hostname
            && PACKET_equal(&hostname, s->session->tlsext_hostname,
                            strlen(s->session->tlsext_hostname));
    }

    return 1;
}

#ifndef OPENSSL_NO_SRP
static int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al)
{
    PACKET srp_I;

    if (!PACKET_as_length_prefixed_1(pkt, &srp_I)
            || PACKET_contains_zero_byte(&srp_I)) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    /*
     * TODO(openssl-team): currently, we re-authenticate the user
     * upon resumption. Instead, we MUST ignore the login.
     */
    if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
        *al = TLS1_AD_INTERNAL_ERROR;
        return 0;
    }

    return 1;
}
#endif

#ifndef OPENSSL_NO_EC
static int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al)
{
    PACKET ec_point_format_list;

    if (!PACKET_as_length_prefixed_1(pkt, &ec_point_format_list)
        || PACKET_remaining(&ec_point_format_list) == 0) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    if (!s->hit) {
        if (!PACKET_memdup(&ec_point_format_list,
                           &s->session->tlsext_ecpointformatlist,
                           &s->session->tlsext_ecpointformatlist_length)) {
            *al = TLS1_AD_INTERNAL_ERROR;
            return 0;
        }
    }

    return 1;
}
#endif                          /* OPENSSL_NO_EC */

static int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al)
{
    if (s->tls_session_ticket_ext_cb &&
            !s->tls_session_ticket_ext_cb(s, PACKET_data(pkt),
                                          PACKET_remaining(pkt),
                                          s->tls_session_ticket_ext_cb_arg)) {
        *al = TLS1_AD_INTERNAL_ERROR;
        return 0;
    }

    return 1;
}

static int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al)
{
    PACKET supported_sig_algs;

    if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs)
            || (PACKET_remaining(&supported_sig_algs) % 2) != 0
            || PACKET_remaining(&supported_sig_algs) == 0) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    if (!s->hit && !tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs),
                                      PACKET_remaining(&supported_sig_algs))) {
        *al = TLS1_AD_INTERNAL_ERROR;
        return 0;
    }

    return 1;
}

static int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al)
{
    if (!PACKET_get_1(pkt, (unsigned int *)&s->tlsext_status_type)) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }
#ifndef OPENSSL_NO_OCSP
    if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
        const unsigned char *ext_data;
        PACKET responder_id_list, exts;
        if (!PACKET_get_length_prefixed_2 (pkt, &responder_id_list)) {
            *al = SSL_AD_DECODE_ERROR;
            return 0;
        }

        /*
         * We remove any OCSP_RESPIDs from a previous handshake
         * to prevent unbounded memory growth - CVE-2016-6304
         */
        sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
        if (PACKET_remaining(&responder_id_list) > 0) {
            s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
            if (s->tlsext_ocsp_ids == NULL) {
                *al = SSL_AD_INTERNAL_ERROR;
                return 0;
            }
        } else {
            s->tlsext_ocsp_ids = NULL;
        }

        while (PACKET_remaining(&responder_id_list) > 0) {
            OCSP_RESPID *id;
            PACKET responder_id;
            const unsigned char *id_data;

            if (!PACKET_get_length_prefixed_2(&responder_id_list,
                                              &responder_id)
                    || PACKET_remaining(&responder_id) == 0) {
                *al = SSL_AD_DECODE_ERROR;
                return 0;
            }

            id_data = PACKET_data(&responder_id);
            /* TODO(size_t): Convert d2i_* to size_t */
            id = d2i_OCSP_RESPID(NULL, &id_data,
                                 (int)PACKET_remaining(&responder_id));
            if (id == NULL) {
                *al = SSL_AD_DECODE_ERROR;
                return 0;
            }

            if (id_data != PACKET_end(&responder_id)) {
                OCSP_RESPID_free(id);
                *al = SSL_AD_DECODE_ERROR;
                return 0;
            }

            if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
                OCSP_RESPID_free(id);
                *al = SSL_AD_INTERNAL_ERROR;
                return 0;
            }
        }

        /* Read in request_extensions */
        if (!PACKET_as_length_prefixed_2(pkt, &exts)) {
            *al = SSL_AD_DECODE_ERROR;
            return 0;
        }

        if (PACKET_remaining(&exts) > 0) {
            ext_data = PACKET_data(&exts);
            sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
                                       X509_EXTENSION_free);
            s->tlsext_ocsp_exts =
                d2i_X509_EXTENSIONS(NULL, &ext_data,
                                    (int)PACKET_remaining(&exts));
            if (s->tlsext_ocsp_exts == NULL || ext_data != PACKET_end(&exts)) {
                *al = SSL_AD_DECODE_ERROR;
                return 0;
            }
        }
    } else
#endif
    {
        /*
         * We don't know what to do with any other type so ignore it.
         */
        s->tlsext_status_type = -1;
    }

    return 1;
}

#ifndef OPENSSL_NO_NEXTPROTONEG
static int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al)
{
    if (s->s3->tmp.finish_md_len == 0) {
        /*-
         * We shouldn't accept this extension on a
         * renegotiation.
         *
         * s->new_session will be set on renegotiation, but we
         * probably shouldn't rely that it couldn't be set on
         * the initial renegotiation too in certain cases (when
         * there's some other reason to disallow resuming an
         * earlier session -- the current code won't be doing
         * anything like that, but this might change).
         *
         * A valid sign that there's been a previous handshake
         * in this connection is if s->s3->tmp.finish_md_len >
         * 0.  (We are talking about a check that will happen
         * in the Hello protocol round, well before a new
         * Finished message could have been computed.)
         */
        s->s3->next_proto_neg_seen = 1;
    }

    return 1;
}
#endif

/*
 * Save the ALPN extension in a ClientHello.
 * pkt: the contents of the ALPN extension, not including type and length.
 * al: a pointer to the  alert value to send in the event of a failure.
 * returns: 1 on success, 0 on error.
 */
static int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al)
{
    PACKET protocol_list, save_protocol_list, protocol;

    if (s->s3->tmp.finish_md_len != 0)
        return 1;

    if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
        || PACKET_remaining(&protocol_list) < 2) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    save_protocol_list = protocol_list;
    do {
        /* Protocol names can't be empty. */
        if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
                || PACKET_remaining(&protocol) == 0) {
            *al = SSL_AD_DECODE_ERROR;
            return 0;
        }
    } while (PACKET_remaining(&protocol_list) != 0);

    if (!PACKET_memdup(&save_protocol_list,
                       &s->s3->alpn_proposed, &s->s3->alpn_proposed_len)) {
        *al = TLS1_AD_INTERNAL_ERROR;
        return 0;
    }

    return 1;
}

#ifndef OPENSSL_NO_SRTP
static int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al)
{
    SRTP_PROTECTION_PROFILE *sprof;
    STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
    unsigned int ct, mki_len, id;
    int i, srtp_pref;
    PACKET subpkt;

    /* Ignore this if we have no SRTP profiles */
    if (SSL_get_srtp_profiles(s) == NULL)
        return 1;

    /* Pull off the length of the cipher suite list  and check it is even */
    if (!PACKET_get_net_2(pkt, &ct)
        || (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    srvr = SSL_get_srtp_profiles(s);
    s->srtp_profile = NULL;
    /* Search all profiles for a match initially */
    srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);

    while (PACKET_remaining(&subpkt)) {
        if (!PACKET_get_net_2(&subpkt, &id)) {
            SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
                   SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
            *al = SSL_AD_DECODE_ERROR;
            return 0;
        }

        /*
         * Only look for match in profiles of higher preference than
         * current match.
         * If no profiles have been have been configured then this
         * does nothing.
         */
        for (i = 0; i < srtp_pref; i++) {
            sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
            if (sprof->id == id) {
                s->srtp_profile = sprof;
                srtp_pref = i;
                break;
            }
        }
    }

    /*
     * Now extract the MKI value as a sanity check, but discard it for now
     */
    if (!PACKET_get_1(pkt, &mki_len)) {
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    if (!PACKET_forward(pkt, mki_len)
        || PACKET_remaining(pkt)) {
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, SSL_R_BAD_SRTP_MKI_VALUE);
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    return 1;
}
#endif

static int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al)
{
    if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC))
        s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;

    return 1;
}

/*
 * Checks a list of |groups| to determine if the |group_id| is in it. If it is
 * and |checkallow| is 1 then additionally check if the group is allowed to be
 * used. Returns 1 if the group is in the list (and allowed if |checkallow| is
 * 1) or 0 otherwise.
 */
static int check_in_list(SSL *s, unsigned int group_id,
                         const unsigned char *groups, size_t num_groups,
                         int checkallow)
{
    size_t i;

    if (groups == NULL || num_groups == 0)
        return 0;

    for (i = 0; i < num_groups; i++, groups += 2) {
        unsigned int share_id = (groups[0] << 8) | (groups[1]);

        if (group_id == share_id
                && (!checkallow || tls_curve_allowed(s, groups,
                                                     SSL_SECOP_CURVE_CHECK))) {
            break;
        }
    }

    /* If i == num_groups then not in the list */
    return i < num_groups;
}

/*
 * Process a key_share extension received in the ClientHello. |pkt| contains
 * the raw PACKET data for the extension. Returns 1 on success or 0 on failure.
 * If a failure occurs then |*al| is set to an appropriate alert value.
 */
static int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al)
{
    unsigned int group_id;
    PACKET key_share_list, encoded_pt;
    const unsigned char *clntcurves, *srvrcurves;
    size_t clnt_num_curves, srvr_num_curves;
    int group_nid, found = 0;
    unsigned int curve_flags;

    if (s->hit)
        return 1;

    /* Sanity check */
    if (s->s3->peer_tmp != NULL) {
        *al = SSL_AD_INTERNAL_ERROR;
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
        return 0;
    }

    if (!PACKET_as_length_prefixed_2(pkt, &key_share_list)) {
        *al = SSL_AD_HANDSHAKE_FAILURE;
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
        return 0;
    }

    /* Get our list of supported curves */
    if (!tls1_get_curvelist(s, 0, &srvrcurves, &srvr_num_curves)) {
        *al = SSL_AD_INTERNAL_ERROR;
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
        return 0;
    }

    /* Get the clients list of supported curves */
    if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
        *al = SSL_AD_INTERNAL_ERROR;
        SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
        return 0;
    }

    while (PACKET_remaining(&key_share_list) > 0) {
        if (!PACKET_get_net_2(&key_share_list, &group_id)
                || !PACKET_get_length_prefixed_2(&key_share_list, &encoded_pt)
                || PACKET_remaining(&encoded_pt) == 0) {
            *al = SSL_AD_HANDSHAKE_FAILURE;
            SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
                   SSL_R_LENGTH_MISMATCH);
            return 0;
        }

        /*
         * If we already found a suitable key_share we loop through the
         * rest to verify the structure, but don't process them.
         */
        if (found)
            continue;

        /* Check if this share is in supported_groups sent from client */
        if (!check_in_list(s, group_id, clntcurves, clnt_num_curves, 0)) {
            *al = SSL_AD_HANDSHAKE_FAILURE;
            SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
            return 0;
        }

        /* Check if this share is for a group we can use */
        if (!check_in_list(s, group_id, srvrcurves, srvr_num_curves, 1)) {
            /* Share not suitable */
            continue;
        }

        group_nid = tls1_ec_curve_id2nid(group_id, &curve_flags);

        if (group_nid == 0) {
            *al = SSL_AD_INTERNAL_ERROR;
            SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
                   SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
            return 0;
        }

        if ((curve_flags & TLS_CURVE_TYPE) == TLS_CURVE_CUSTOM) {
            /* Can happen for some curves, e.g. X25519 */
            EVP_PKEY *key = EVP_PKEY_new();

            if (key == NULL || !EVP_PKEY_set_type(key, group_nid)) {
                *al = SSL_AD_INTERNAL_ERROR;
                SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
                EVP_PKEY_free(key);
                return 0;
            }
            s->s3->peer_tmp = key;
        } else {
            /* Set up EVP_PKEY with named curve as parameters */
            EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
            if (pctx == NULL
                    || EVP_PKEY_paramgen_init(pctx) <= 0
                    || EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx,
                                                              group_nid) <= 0
                    || EVP_PKEY_paramgen(pctx, &s->s3->peer_tmp) <= 0) {
                *al = SSL_AD_INTERNAL_ERROR;
                SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
                EVP_PKEY_CTX_free(pctx);
                return 0;
            }
            EVP_PKEY_CTX_free(pctx);
            pctx = NULL;
        }
        s->s3->group_id = group_id;

        if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
                PACKET_data(&encoded_pt),
                PACKET_remaining(&encoded_pt))) {
            *al = SSL_AD_DECODE_ERROR;
            SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_ECPOINT);
            return 0;
        }

        found = 1;
    }

    return 1;
}

#ifndef OPENSSL_NO_EC
static int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al)
{
    PACKET supported_groups_list;

    /* Each group is 2 bytes and we must have at least 1. */
    if (!PACKET_as_length_prefixed_2(pkt, &supported_groups_list)
            || PACKET_remaining(&supported_groups_list) == 0
            || (PACKET_remaining(&supported_groups_list) % 2) != 0) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    if (!s->hit
            && !PACKET_memdup(&supported_groups_list,
                              &s->session->tlsext_supportedgroupslist,
                              &s->session->tlsext_supportedgroupslist_length)) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    return 1;
}
#endif

static int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al)
{
    /* The extension must always be empty */
    if (PACKET_remaining(pkt) != 0) {
        *al = SSL_AD_DECODE_ERROR;
        return 0;
    }

    s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;

    return 1;
}
+649 −0

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+24 −0
Original line number Diff line number Diff line
@@ -155,3 +155,27 @@ __owur int tls_parse_extension(SSL *s, int type, int context, RAW_EXTENSION *ext
                               size_t numexts, int *al);
__owur int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
                                    int *al);

/* Server Extension processing */
int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRP
int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al);
#endif
#ifndef OPENSSL_NO_EC
int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al);
#endif
int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_NEXTPROTONEG
int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al);
#endif
int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRTP
int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al);
#endif
int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al);