path: root/contrib/libs/openssl/ssl/statem/extensions_clnt.c

/* 
 * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
 * 
 * Licensed under the OpenSSL license (the "License").  You may not use 
 * this file except in compliance with the License.  You can obtain a copy 
 * in the file LICENSE in the source distribution or at 
 * https://www.openssl.org/source/license.html 
 */ 
 
#include <openssl/ocsp.h> 
#include "../ssl_local.h"
#include "internal/cryptlib.h" 
#include "statem_local.h"
 
EXT_RETURN tls_construct_ctos_renegotiate(SSL *s, WPACKET *pkt, 
                                          unsigned int context, X509 *x, 
                                          size_t chainidx) 
{ 
    /* Add RI if renegotiating */ 
    if (!s->renegotiate) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_renegotiate) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_sub_memcpy_u8(pkt, s->s3->previous_client_finished, 
                               s->s3->previous_client_finished_len) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_RENEGOTIATE, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
EXT_RETURN tls_construct_ctos_server_name(SSL *s, WPACKET *pkt, 
                                          unsigned int context, X509 *x, 
                                          size_t chainidx) 
{ 
    if (s->ext.hostname == NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    /* Add TLS extension servername to the Client Hello message */ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_server_name) 
               /* Sub-packet for server_name extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
               /* Sub-packet for servername list (always 1 hostname)*/ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_put_bytes_u8(pkt, TLSEXT_NAMETYPE_host_name) 
            || !WPACKET_sub_memcpy_u16(pkt, s->ext.hostname, 
                                       strlen(s->ext.hostname)) 
            || !WPACKET_close(pkt) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_SERVER_NAME, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
/* Push a Max Fragment Len extension into ClientHello */ 
EXT_RETURN tls_construct_ctos_maxfragmentlen(SSL *s, WPACKET *pkt, 
                                             unsigned int context, X509 *x, 
                                             size_t chainidx) 
{ 
    if (s->ext.max_fragment_len_mode == TLSEXT_max_fragment_length_DISABLED) 
        return EXT_RETURN_NOT_SENT; 
 
    /* Add Max Fragment Length extension if client enabled it. */ 
    /*- 
     * 4 bytes for this extension type and extension length 
     * 1 byte for the Max Fragment Length code value. 
     */ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_max_fragment_length) 
            /* Sub-packet for Max Fragment Length extension (1 byte) */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_put_bytes_u8(pkt, s->ext.max_fragment_len_mode) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_MAXFRAGMENTLEN, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
#ifndef OPENSSL_NO_SRP 
EXT_RETURN tls_construct_ctos_srp(SSL *s, WPACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    /* Add SRP username if there is one */ 
    if (s->srp_ctx.login == NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_srp) 
               /* Sub-packet for SRP extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_start_sub_packet_u8(pkt) 
               /* login must not be zero...internal error if so */ 
            || !WPACKET_set_flags(pkt, WPACKET_FLAGS_NON_ZERO_LENGTH) 
            || !WPACKET_memcpy(pkt, s->srp_ctx.login, 
                               strlen(s->srp_ctx.login)) 
            || !WPACKET_close(pkt) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_SRP, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
#endif 
 
#ifndef OPENSSL_NO_EC 
static int use_ecc(SSL *s) 
{ 
    int i, end, ret = 0; 
    unsigned long alg_k, alg_a; 
    STACK_OF(SSL_CIPHER) *cipher_stack = NULL; 
 
    /* See if we support any ECC ciphersuites */ 
    if (s->version == SSL3_VERSION) 
        return 0; 
 
    cipher_stack = SSL_get1_supported_ciphers(s); 
    end = sk_SSL_CIPHER_num(cipher_stack); 
    for (i = 0; i < end; i++) { 
        const SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i); 
 
        alg_k = c->algorithm_mkey; 
        alg_a = c->algorithm_auth; 
        if ((alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) 
                || (alg_a & SSL_aECDSA) 
                || c->min_tls >= TLS1_3_VERSION) { 
            ret = 1; 
            break; 
        } 
    } 
 
    sk_SSL_CIPHER_free(cipher_stack); 
    return ret; 
} 
 
EXT_RETURN tls_construct_ctos_ec_pt_formats(SSL *s, WPACKET *pkt, 
                                            unsigned int context, X509 *x, 
                                            size_t chainidx) 
{ 
    const unsigned char *pformats; 
    size_t num_formats; 
 
    if (!use_ecc(s)) 
        return EXT_RETURN_NOT_SENT; 
 
    /* Add TLS extension ECPointFormats to the ClientHello message */ 
    tls1_get_formatlist(s, &pformats, &num_formats); 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_ec_point_formats) 
               /* Sub-packet for formats extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_sub_memcpy_u8(pkt, pformats, num_formats) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_EC_PT_FORMATS, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
EXT_RETURN tls_construct_ctos_supported_groups(SSL *s, WPACKET *pkt, 
                                               unsigned int context, X509 *x, 
                                               size_t chainidx) 
{ 
    const uint16_t *pgroups = NULL; 
    size_t num_groups = 0, i; 
 
    if (!use_ecc(s)) 
        return EXT_RETURN_NOT_SENT; 
 
    /* 
     * Add TLS extension supported_groups to the ClientHello message 
     */ 
    /* TODO(TLS1.3): Add support for DHE groups */ 
    tls1_get_supported_groups(s, &pgroups, &num_groups); 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_groups) 
               /* Sub-packet for supported_groups extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_start_sub_packet_u16(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
    /* Copy curve ID if supported */ 
    for (i = 0; i < num_groups; i++) { 
        uint16_t ctmp = pgroups[i]; 
 
        if (tls_curve_allowed(s, ctmp, SSL_SECOP_CURVE_SUPPORTED)) { 
            if (!WPACKET_put_bytes_u16(pkt, ctmp)) { 
                    SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                             SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS, 
                             ERR_R_INTERNAL_ERROR); 
                    return EXT_RETURN_FAIL; 
                } 
        } 
    } 
    if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
#endif 
 
EXT_RETURN tls_construct_ctos_session_ticket(SSL *s, WPACKET *pkt, 
                                             unsigned int context, X509 *x, 
                                             size_t chainidx) 
{ 
    size_t ticklen; 
 
    if (!tls_use_ticket(s)) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!s->new_session && s->session != NULL 
            && s->session->ext.tick != NULL 
            && s->session->ssl_version != TLS1_3_VERSION) { 
        ticklen = s->session->ext.ticklen; 
    } else if (s->session && s->ext.session_ticket != NULL 
               && s->ext.session_ticket->data != NULL) { 
        ticklen = s->ext.session_ticket->length; 
        s->session->ext.tick = OPENSSL_malloc(ticklen); 
        if (s->session->ext.tick == NULL) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_SESSION_TICKET, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        memcpy(s->session->ext.tick, 
               s->ext.session_ticket->data, ticklen); 
        s->session->ext.ticklen = ticklen; 
    } else { 
        ticklen = 0; 
    } 
 
    if (ticklen == 0 && s->ext.session_ticket != NULL && 
            s->ext.session_ticket->data == NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_session_ticket) 
            || !WPACKET_sub_memcpy_u16(pkt, s->session->ext.tick, ticklen)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_SESSION_TICKET, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
EXT_RETURN tls_construct_ctos_sig_algs(SSL *s, WPACKET *pkt, 
                                       unsigned int context, X509 *x, 
                                       size_t chainidx) 
{ 
    size_t salglen; 
    const uint16_t *salg; 
 
    if (!SSL_CLIENT_USE_SIGALGS(s)) 
        return EXT_RETURN_NOT_SENT; 
 
    salglen = tls12_get_psigalgs(s, 1, &salg); 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_signature_algorithms) 
               /* Sub-packet for sig-algs extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
               /* Sub-packet for the actual list */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !tls12_copy_sigalgs(s, pkt, salg, salglen) 
            || !WPACKET_close(pkt) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_SIG_ALGS, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
#ifndef OPENSSL_NO_OCSP 
EXT_RETURN tls_construct_ctos_status_request(SSL *s, WPACKET *pkt, 
                                             unsigned int context, X509 *x, 
                                             size_t chainidx) 
{ 
    int i; 
 
    /* This extension isn't defined for client Certificates */ 
    if (x != NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    if (s->ext.status_type != TLSEXT_STATUSTYPE_ocsp) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_status_request) 
               /* Sub-packet for status request extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_put_bytes_u8(pkt, TLSEXT_STATUSTYPE_ocsp) 
               /* Sub-packet for the ids */ 
            || !WPACKET_start_sub_packet_u16(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_STATUS_REQUEST, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
    for (i = 0; i < sk_OCSP_RESPID_num(s->ext.ocsp.ids); i++) { 
        unsigned char *idbytes; 
        OCSP_RESPID *id = sk_OCSP_RESPID_value(s->ext.ocsp.ids, i); 
        int idlen = i2d_OCSP_RESPID(id, NULL); 
 
        if (idlen <= 0 
                   /* Sub-packet for an individual id */ 
                || !WPACKET_sub_allocate_bytes_u16(pkt, idlen, &idbytes) 
                || i2d_OCSP_RESPID(id, &idbytes) != idlen) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_STATUS_REQUEST, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
    } 
    if (!WPACKET_close(pkt) 
            || !WPACKET_start_sub_packet_u16(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_STATUS_REQUEST, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
    if (s->ext.ocsp.exts) { 
        unsigned char *extbytes; 
        int extlen = i2d_X509_EXTENSIONS(s->ext.ocsp.exts, NULL); 
 
        if (extlen < 0) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_STATUS_REQUEST, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        if (!WPACKET_allocate_bytes(pkt, extlen, &extbytes) 
                || i2d_X509_EXTENSIONS(s->ext.ocsp.exts, &extbytes) 
                   != extlen) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_STATUS_REQUEST, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
       } 
    } 
    if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_STATUS_REQUEST, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
#endif 
 
#ifndef OPENSSL_NO_NEXTPROTONEG 
EXT_RETURN tls_construct_ctos_npn(SSL *s, WPACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    if (s->ctx->ext.npn_select_cb == NULL || !SSL_IS_FIRST_HANDSHAKE(s)) 
        return EXT_RETURN_NOT_SENT; 
 
    /* 
     * The client advertises an empty extension to indicate its support 
     * for Next Protocol Negotiation 
     */ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_next_proto_neg) 
            || !WPACKET_put_bytes_u16(pkt, 0)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_NPN, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
#endif 
 
EXT_RETURN tls_construct_ctos_alpn(SSL *s, WPACKET *pkt, unsigned int context, 
                                   X509 *x, size_t chainidx) 
{ 
    s->s3->alpn_sent = 0; 
 
    if (s->ext.alpn == NULL || !SSL_IS_FIRST_HANDSHAKE(s)) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, 
                TLSEXT_TYPE_application_layer_protocol_negotiation) 
               /* Sub-packet ALPN extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_sub_memcpy_u16(pkt, s->ext.alpn, s->ext.alpn_len) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_ALPN, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
    s->s3->alpn_sent = 1; 
 
    return EXT_RETURN_SENT; 
} 
 
 
#ifndef OPENSSL_NO_SRTP 
EXT_RETURN tls_construct_ctos_use_srtp(SSL *s, WPACKET *pkt, 
                                       unsigned int context, X509 *x, 
                                       size_t chainidx) 
{ 
    STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = SSL_get_srtp_profiles(s); 
    int i, end; 
 
    if (clnt == NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_use_srtp) 
               /* Sub-packet for SRTP extension */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
               /* Sub-packet for the protection profile list */ 
            || !WPACKET_start_sub_packet_u16(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_USE_SRTP, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    end = sk_SRTP_PROTECTION_PROFILE_num(clnt); 
    for (i = 0; i < end; i++) { 
        const SRTP_PROTECTION_PROFILE *prof = 
            sk_SRTP_PROTECTION_PROFILE_value(clnt, i); 
 
        if (prof == NULL || !WPACKET_put_bytes_u16(pkt, prof->id)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_USE_SRTP, ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
    } 
    if (!WPACKET_close(pkt) 
               /* Add an empty use_mki value */ 
            || !WPACKET_put_bytes_u8(pkt, 0) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_USE_SRTP, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
#endif 
 
EXT_RETURN tls_construct_ctos_etm(SSL *s, WPACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    if (s->options & SSL_OP_NO_ENCRYPT_THEN_MAC) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_encrypt_then_mac) 
            || !WPACKET_put_bytes_u16(pkt, 0)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_ETM, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
#ifndef OPENSSL_NO_CT 
EXT_RETURN tls_construct_ctos_sct(SSL *s, WPACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    if (s->ct_validation_callback == NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    /* Not defined for client Certificates */ 
    if (x != NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_signed_certificate_timestamp) 
            || !WPACKET_put_bytes_u16(pkt, 0)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_SCT, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
#endif 
 
EXT_RETURN tls_construct_ctos_ems(SSL *s, WPACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_extended_master_secret) 
            || !WPACKET_put_bytes_u16(pkt, 0)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_EMS, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
EXT_RETURN tls_construct_ctos_supported_versions(SSL *s, WPACKET *pkt, 
                                                 unsigned int context, X509 *x, 
                                                 size_t chainidx) 
{ 
    int currv, min_version, max_version, reason; 
 
    reason = ssl_get_min_max_version(s, &min_version, &max_version, NULL); 
    if (reason != 0) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_VERSIONS, reason); 
        return EXT_RETURN_FAIL; 
    } 
 
    /* 
     * Don't include this if we can't negotiate TLSv1.3. We can do a straight 
     * comparison here because we will never be called in DTLS. 
     */ 
    if (max_version < TLS1_3_VERSION) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_versions) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_start_sub_packet_u8(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_VERSIONS, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    for (currv = max_version; currv >= min_version; currv--) { 
        if (!WPACKET_put_bytes_u16(pkt, currv)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_VERSIONS, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
    } 
    if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_VERSIONS, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
/* 
 * Construct a psk_kex_modes extension. 
 */ 
EXT_RETURN tls_construct_ctos_psk_kex_modes(SSL *s, WPACKET *pkt, 
                                            unsigned int context, X509 *x, 
                                            size_t chainidx) 
{ 
#ifndef OPENSSL_NO_TLS1_3 
    int nodhe = s->options & SSL_OP_ALLOW_NO_DHE_KEX; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_psk_kex_modes) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_start_sub_packet_u8(pkt) 
            || !WPACKET_put_bytes_u8(pkt, TLSEXT_KEX_MODE_KE_DHE) 
            || (nodhe && !WPACKET_put_bytes_u8(pkt, TLSEXT_KEX_MODE_KE)) 
            || !WPACKET_close(pkt) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_PSK_KEX_MODES, ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_KE_DHE; 
    if (nodhe) 
        s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE; 
#endif 
 
    return EXT_RETURN_SENT; 
} 
 
#ifndef OPENSSL_NO_TLS1_3 
static int add_key_share(SSL *s, WPACKET *pkt, unsigned int curve_id) 
{ 
    unsigned char *encoded_point = NULL; 
    EVP_PKEY *key_share_key = NULL; 
    size_t encodedlen; 
 
    if (s->s3->tmp.pkey != NULL) { 
        if (!ossl_assert(s->hello_retry_request == SSL_HRR_PENDING)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_ADD_KEY_SHARE, 
                     ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
        /* 
         * Could happen if we got an HRR that wasn't requesting a new key_share 
         */ 
        key_share_key = s->s3->tmp.pkey; 
    } else { 
        key_share_key = ssl_generate_pkey_group(s, curve_id); 
        if (key_share_key == NULL) { 
            /* SSLfatal() already called */ 
            return 0; 
        } 
    } 
 
    /* Encode the public key. */ 
    encodedlen = EVP_PKEY_get1_tls_encodedpoint(key_share_key, 
                                                &encoded_point); 
    if (encodedlen == 0) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_ADD_KEY_SHARE, ERR_R_EC_LIB); 
        goto err; 
    } 
 
    /* Create KeyShareEntry */ 
    if (!WPACKET_put_bytes_u16(pkt, curve_id) 
            || !WPACKET_sub_memcpy_u16(pkt, encoded_point, encodedlen)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_ADD_KEY_SHARE, 
                 ERR_R_INTERNAL_ERROR); 
        goto err; 
    } 
 
    /* 
     * TODO(TLS1.3): When changing to send more than one key_share we're 
     * going to need to be able to save more than one EVP_PKEY. For now 
     * we reuse the existing tmp.pkey 
     */ 
    s->s3->tmp.pkey = key_share_key; 
    s->s3->group_id = curve_id; 
    OPENSSL_free(encoded_point); 
 
    return 1; 
 err: 
    if (s->s3->tmp.pkey == NULL) 
        EVP_PKEY_free(key_share_key); 
    OPENSSL_free(encoded_point); 
    return 0; 
} 
#endif 
 
EXT_RETURN tls_construct_ctos_key_share(SSL *s, WPACKET *pkt, 
                                        unsigned int context, X509 *x, 
                                        size_t chainidx) 
{ 
#ifndef OPENSSL_NO_TLS1_3 
    size_t i, num_groups = 0; 
    const uint16_t *pgroups = NULL; 
    uint16_t curve_id = 0; 
 
    /* key_share extension */ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share) 
               /* Extension data sub-packet */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
               /* KeyShare list sub-packet */ 
            || !WPACKET_start_sub_packet_u16(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    tls1_get_supported_groups(s, &pgroups, &num_groups); 
 
    /* 
     * TODO(TLS1.3): Make the number of key_shares sent configurable. For 
     * now, just send one 
     */ 
    if (s->s3->group_id != 0) { 
        curve_id = s->s3->group_id; 
    } else { 
        for (i = 0; i < num_groups; i++) { 
 
            if (!tls_curve_allowed(s, pgroups[i], SSL_SECOP_CURVE_SUPPORTED)) 
                continue; 
 
            curve_id = pgroups[i]; 
            break; 
        } 
    } 
 
    if (curve_id == 0) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, 
                 SSL_R_NO_SUITABLE_KEY_SHARE); 
        return EXT_RETURN_FAIL; 
    } 
 
    if (!add_key_share(s, pkt, curve_id)) { 
        /* SSLfatal() already called */ 
        return EXT_RETURN_FAIL; 
    } 
 
    if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
    return EXT_RETURN_SENT; 
#else 
    return EXT_RETURN_NOT_SENT; 
#endif 
} 
 
EXT_RETURN tls_construct_ctos_cookie(SSL *s, WPACKET *pkt, unsigned int context, 
                                     X509 *x, size_t chainidx) 
{ 
    EXT_RETURN ret = EXT_RETURN_FAIL; 
 
    /* Should only be set if we've had an HRR */ 
    if (s->ext.tls13_cookie_len == 0) 
        return EXT_RETURN_NOT_SENT; 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_cookie) 
               /* Extension data sub-packet */ 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_sub_memcpy_u16(pkt, s->ext.tls13_cookie, 
                                       s->ext.tls13_cookie_len) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_COOKIE, 
                 ERR_R_INTERNAL_ERROR); 
        goto end; 
    } 
 
    ret = EXT_RETURN_SENT; 
 end: 
    OPENSSL_free(s->ext.tls13_cookie); 
    s->ext.tls13_cookie = NULL; 
    s->ext.tls13_cookie_len = 0; 
 
    return ret; 
} 
 
EXT_RETURN tls_construct_ctos_early_data(SSL *s, WPACKET *pkt, 
                                         unsigned int context, X509 *x, 
                                         size_t chainidx) 
{ 
#ifndef OPENSSL_NO_PSK 
    char identity[PSK_MAX_IDENTITY_LEN + 1]; 
#endif  /* OPENSSL_NO_PSK */ 
    const unsigned char *id = NULL; 
    size_t idlen = 0; 
    SSL_SESSION *psksess = NULL; 
    SSL_SESSION *edsess = NULL; 
    const EVP_MD *handmd = NULL; 
 
    if (s->hello_retry_request == SSL_HRR_PENDING) 
        handmd = ssl_handshake_md(s); 
 
    if (s->psk_use_session_cb != NULL 
            && (!s->psk_use_session_cb(s, handmd, &id, &idlen, &psksess) 
                || (psksess != NULL 
                    && psksess->ssl_version != TLS1_3_VERSION))) { 
        SSL_SESSION_free(psksess); 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                 SSL_R_BAD_PSK); 
        return EXT_RETURN_FAIL; 
    } 
 
#ifndef OPENSSL_NO_PSK 
    if (psksess == NULL && s->psk_client_callback != NULL) { 
        unsigned char psk[PSK_MAX_PSK_LEN]; 
        size_t psklen = 0; 
 
        memset(identity, 0, sizeof(identity)); 
        psklen = s->psk_client_callback(s, NULL, identity, sizeof(identity) - 1, 
                                        psk, sizeof(psk)); 
 
        if (psklen > PSK_MAX_PSK_LEN) { 
            SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, 
                     SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } else if (psklen > 0) { 
            const unsigned char tls13_aes128gcmsha256_id[] = { 0x13, 0x01 }; 
            const SSL_CIPHER *cipher; 
 
            idlen = strlen(identity); 
            if (idlen > PSK_MAX_IDENTITY_LEN) { 
                SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                         SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                         ERR_R_INTERNAL_ERROR); 
                return EXT_RETURN_FAIL; 
            } 
            id = (unsigned char *)identity; 
 
            /* 
             * We found a PSK using an old style callback. We don't know 
             * the digest so we default to SHA256 as per the TLSv1.3 spec 
             */ 
            cipher = SSL_CIPHER_find(s, tls13_aes128gcmsha256_id); 
            if (cipher == NULL) { 
                SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                         SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                         ERR_R_INTERNAL_ERROR); 
                return EXT_RETURN_FAIL; 
            } 
 
            psksess = SSL_SESSION_new(); 
            if (psksess == NULL 
                    || !SSL_SESSION_set1_master_key(psksess, psk, psklen) 
                    || !SSL_SESSION_set_cipher(psksess, cipher) 
                    || !SSL_SESSION_set_protocol_version(psksess, TLS1_3_VERSION)) { 
                SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                         SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                         ERR_R_INTERNAL_ERROR); 
                OPENSSL_cleanse(psk, psklen); 
                return EXT_RETURN_FAIL; 
            } 
            OPENSSL_cleanse(psk, psklen); 
        } 
    } 
#endif  /* OPENSSL_NO_PSK */ 
 
    SSL_SESSION_free(s->psksession); 
    s->psksession = psksess; 
    if (psksess != NULL) { 
        OPENSSL_free(s->psksession_id); 
        s->psksession_id = OPENSSL_memdup(id, idlen); 
        if (s->psksession_id == NULL) { 
            s->psksession_id_len = 0;
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        s->psksession_id_len = idlen; 
    } 
 
    if (s->early_data_state != SSL_EARLY_DATA_CONNECTING 
            || (s->session->ext.max_early_data == 0 
                && (psksess == NULL || psksess->ext.max_early_data == 0))) { 
        s->max_early_data = 0; 
        return EXT_RETURN_NOT_SENT; 
    } 
    edsess = s->session->ext.max_early_data != 0 ? s->session : psksess; 
    s->max_early_data = edsess->ext.max_early_data; 
 
    if (edsess->ext.hostname != NULL) { 
        if (s->ext.hostname == NULL 
                || (s->ext.hostname != NULL 
                    && strcmp(s->ext.hostname, edsess->ext.hostname) != 0)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                     SSL_R_INCONSISTENT_EARLY_DATA_SNI); 
            return EXT_RETURN_FAIL; 
        } 
    } 
 
    if ((s->ext.alpn == NULL && edsess->ext.alpn_selected != NULL)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                 SSL_R_INCONSISTENT_EARLY_DATA_ALPN); 
        return EXT_RETURN_FAIL; 
    } 
 
    /* 
     * Verify that we are offering an ALPN protocol consistent with the early 
     * data. 
     */ 
    if (edsess->ext.alpn_selected != NULL) { 
        PACKET prots, alpnpkt; 
        int found = 0; 
 
        if (!PACKET_buf_init(&prots, s->ext.alpn, s->ext.alpn_len)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        while (PACKET_get_length_prefixed_1(&prots, &alpnpkt)) { 
            if (PACKET_equal(&alpnpkt, edsess->ext.alpn_selected, 
                             edsess->ext.alpn_selected_len)) { 
                found = 1; 
                break; 
            } 
        } 
        if (!found) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                     SSL_R_INCONSISTENT_EARLY_DATA_ALPN); 
            return EXT_RETURN_FAIL; 
        } 
    } 
 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_early_data) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_EARLY_DATA, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    /* 
     * We set this to rejected here. Later, if the server acknowledges the 
     * extension, we set it to accepted. 
     */ 
    s->ext.early_data = SSL_EARLY_DATA_REJECTED; 
    s->ext.early_data_ok = 1; 
 
    return EXT_RETURN_SENT; 
} 
 
#define F5_WORKAROUND_MIN_MSG_LEN   0xff 
#define F5_WORKAROUND_MAX_MSG_LEN   0x200 
 
/* 
 * PSK pre binder overhead = 
 *  2 bytes for TLSEXT_TYPE_psk 
 *  2 bytes for extension length 
 *  2 bytes for identities list length 
 *  2 bytes for identity length 
 *  4 bytes for obfuscated_ticket_age 
 *  2 bytes for binder list length 
 *  1 byte for binder length 
 * The above excludes the number of bytes for the identity itself and the 
 * subsequent binder bytes 
 */ 
#define PSK_PRE_BINDER_OVERHEAD (2 + 2 + 2 + 2 + 4 + 2 + 1) 
 
EXT_RETURN tls_construct_ctos_padding(SSL *s, WPACKET *pkt, 
                                      unsigned int context, X509 *x, 
                                      size_t chainidx) 
{ 
    unsigned char *padbytes; 
    size_t hlen; 
 
    if ((s->options & SSL_OP_TLSEXT_PADDING) == 0) 
        return EXT_RETURN_NOT_SENT; 
 
    /* 
     * Add padding to workaround bugs in F5 terminators. See RFC7685. 
     * This code calculates the length of all extensions added so far but 
     * excludes the PSK extension (because that MUST be written last). Therefore 
     * this extension MUST always appear second to last. 
     */ 
    if (!WPACKET_get_total_written(pkt, &hlen)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PADDING, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    /* 
     * If we're going to send a PSK then that will be written out after this 
     * extension, so we need to calculate how long it is going to be. 
     */ 
    if (s->session->ssl_version == TLS1_3_VERSION 
            && s->session->ext.ticklen != 0 
            && s->session->cipher != NULL) { 
        const EVP_MD *md = ssl_md(s->session->cipher->algorithm2); 
 
        if (md != NULL) { 
            /* 
             * Add the fixed PSK overhead, the identity length and the binder 
             * length. 
             */ 
            hlen +=  PSK_PRE_BINDER_OVERHEAD + s->session->ext.ticklen 
                     + EVP_MD_size(md); 
        } 
    } 
 
    if (hlen > F5_WORKAROUND_MIN_MSG_LEN && hlen < F5_WORKAROUND_MAX_MSG_LEN) { 
        /* Calculate the amount of padding we need to add */ 
        hlen = F5_WORKAROUND_MAX_MSG_LEN - hlen; 
 
        /* 
         * Take off the size of extension header itself (2 bytes for type and 
         * 2 bytes for length bytes), but ensure that the extension is at least 
         * 1 byte long so as not to have an empty extension last (WebSphere 7.x, 
         * 8.x are intolerant of that condition) 
         */ 
        if (hlen > 4) 
            hlen -= 4; 
        else 
            hlen = 1; 
 
        if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_padding) 
                || !WPACKET_sub_allocate_bytes_u16(pkt, hlen, &padbytes)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PADDING, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        memset(padbytes, 0, hlen); 
    } 
 
    return EXT_RETURN_SENT; 
} 
 
/* 
 * Construct the pre_shared_key extension 
 */ 
EXT_RETURN tls_construct_ctos_psk(SSL *s, WPACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
#ifndef OPENSSL_NO_TLS1_3 
    uint32_t now, agesec, agems = 0; 
    size_t reshashsize = 0, pskhashsize = 0, binderoffset, msglen; 
    unsigned char *resbinder = NULL, *pskbinder = NULL, *msgstart = NULL; 
    const EVP_MD *handmd = NULL, *mdres = NULL, *mdpsk = NULL; 
    int dores = 0; 
 
    s->ext.tick_identity = 0;
 
    /* 
     * Note: At this stage of the code we only support adding a single 
     * resumption PSK. If we add support for multiple PSKs then the length 
     * calculations in the padding extension will need to be adjusted. 
     */ 
 
    /* 
     * If this is an incompatible or new session then we have nothing to resume 
     * so don't add this extension. 
     */ 
    if (s->session->ssl_version != TLS1_3_VERSION 
            || (s->session->ext.ticklen == 0 && s->psksession == NULL)) 
        return EXT_RETURN_NOT_SENT; 
 
    if (s->hello_retry_request == SSL_HRR_PENDING) 
        handmd = ssl_handshake_md(s); 
 
    if (s->session->ext.ticklen != 0) { 
        /* Get the digest associated with the ciphersuite in the session */ 
        if (s->session->cipher == NULL) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        mdres = ssl_md(s->session->cipher->algorithm2); 
        if (mdres == NULL) { 
            /* 
             * Don't recognize this cipher so we can't use the session. 
             * Ignore it 
             */ 
            goto dopsksess; 
        } 
 
        if (s->hello_retry_request == SSL_HRR_PENDING && mdres != handmd) { 
            /* 
             * Selected ciphersuite hash does not match the hash for the session 
             * so we can't use it. 
             */ 
            goto dopsksess; 
        } 
 
        /* 
         * Technically the C standard just says time() returns a time_t and says 
         * nothing about the encoding of that type. In practice most 
         * implementations follow POSIX which holds it as an integral type in 
         * seconds since epoch. We've already made the assumption that we can do 
         * this in multiple places in the code, so portability shouldn't be an 
         * issue. 
         */ 
        now = (uint32_t)time(NULL); 
        agesec = now - (uint32_t)s->session->time; 
        /* 
         * We calculate the age in seconds but the server may work in ms. Due to 
         * rounding errors we could overestimate the age by up to 1s. It is 
         * better to underestimate it. Otherwise, if the RTT is very short, when 
         * the server calculates the age reported by the client it could be 
         * bigger than the age calculated on the server - which should never 
         * happen. 
         */ 
        if (agesec > 0) 
            agesec--; 
 
        if (s->session->ext.tick_lifetime_hint < agesec) { 
            /* Ticket is too old. Ignore it. */ 
            goto dopsksess; 
        } 
 
        /* 
         * Calculate age in ms. We're just doing it to nearest second. Should be 
         * good enough. 
         */ 
        agems = agesec * (uint32_t)1000; 
 
        if (agesec != 0 && agems / (uint32_t)1000 != agesec) { 
            /* 
             * Overflow. Shouldn't happen unless this is a *really* old session. 
             * If so we just ignore it. 
             */ 
            goto dopsksess; 
        } 
 
        /* 
         * Obfuscate the age. Overflow here is fine, this addition is supposed 
         * to be mod 2^32. 
         */ 
        agems += s->session->ext.tick_age_add; 
 
        reshashsize = EVP_MD_size(mdres); 
        s->ext.tick_identity++;
        dores = 1; 
    } 
 
 dopsksess: 
    if (!dores && s->psksession == NULL) 
        return EXT_RETURN_NOT_SENT; 
 
    if (s->psksession != NULL) { 
        mdpsk = ssl_md(s->psksession->cipher->algorithm2); 
        if (mdpsk == NULL) { 
            /* 
             * Don't recognize this cipher so we can't use the session. 
             * If this happens it's an application bug. 
             */ 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                     SSL_R_BAD_PSK); 
            return EXT_RETURN_FAIL; 
        } 
 
        if (s->hello_retry_request == SSL_HRR_PENDING && mdpsk != handmd) { 
            /* 
             * Selected ciphersuite hash does not match the hash for the PSK 
             * session. This is an application bug. 
             */ 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                     SSL_R_BAD_PSK); 
            return EXT_RETURN_FAIL; 
        } 
 
        pskhashsize = EVP_MD_size(mdpsk); 
    } 
 
    /* Create the extension, but skip over the binder for now */ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_psk) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_start_sub_packet_u16(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    if (dores) { 
        if (!WPACKET_sub_memcpy_u16(pkt, s->session->ext.tick, 
                                           s->session->ext.ticklen) 
                || !WPACKET_put_bytes_u32(pkt, agems)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
    } 
 
    if (s->psksession != NULL) { 
        if (!WPACKET_sub_memcpy_u16(pkt, s->psksession_id, 
                                    s->psksession_id_len) 
                || !WPACKET_put_bytes_u32(pkt, 0)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                     ERR_R_INTERNAL_ERROR); 
            return EXT_RETURN_FAIL; 
        } 
        s->ext.tick_identity++;
    } 
 
    if (!WPACKET_close(pkt) 
            || !WPACKET_get_total_written(pkt, &binderoffset) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || (dores 
                && !WPACKET_sub_allocate_bytes_u8(pkt, reshashsize, &resbinder)) 
            || (s->psksession != NULL 
                && !WPACKET_sub_allocate_bytes_u8(pkt, pskhashsize, &pskbinder)) 
            || !WPACKET_close(pkt) 
            || !WPACKET_close(pkt) 
            || !WPACKET_get_total_written(pkt, &msglen) 
               /* 
                * We need to fill in all the sub-packet lengths now so we can 
                * calculate the HMAC of the message up to the binders 
                */ 
            || !WPACKET_fill_lengths(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CTOS_PSK, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    msgstart = WPACKET_get_curr(pkt) - msglen; 
 
    if (dores 
            && tls_psk_do_binder(s, mdres, msgstart, binderoffset, NULL, 
                                 resbinder, s->session, 1, 0) != 1) { 
        /* SSLfatal() already called */ 
        return EXT_RETURN_FAIL; 
    } 
 
    if (s->psksession != NULL 
            && tls_psk_do_binder(s, mdpsk, msgstart, binderoffset, NULL, 
                                 pskbinder, s->psksession, 1, 1) != 1) { 
        /* SSLfatal() already called */ 
        return EXT_RETURN_FAIL; 
    } 
 
    return EXT_RETURN_SENT; 
#else 
    return EXT_RETURN_NOT_SENT; 
#endif 
} 
 
EXT_RETURN tls_construct_ctos_post_handshake_auth(SSL *s, WPACKET *pkt, 
                                                  unsigned int context, 
                                                  X509 *x, size_t chainidx) 
{ 
#ifndef OPENSSL_NO_TLS1_3 
    if (!s->pha_enabled) 
        return EXT_RETURN_NOT_SENT; 
 
    /* construct extension - 0 length, no contents */ 
    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_post_handshake_auth) 
            || !WPACKET_start_sub_packet_u16(pkt) 
            || !WPACKET_close(pkt)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                 SSL_F_TLS_CONSTRUCT_CTOS_POST_HANDSHAKE_AUTH, 
                 ERR_R_INTERNAL_ERROR); 
        return EXT_RETURN_FAIL; 
    } 
 
    s->post_handshake_auth = SSL_PHA_EXT_SENT; 
 
    return EXT_RETURN_SENT; 
#else 
    return EXT_RETURN_NOT_SENT; 
#endif 
} 
 
 
/* 
 * Parse the server's renegotiation binding and abort if it's not right 
 */ 
int tls_parse_stoc_renegotiate(SSL *s, PACKET *pkt, unsigned int context, 
                               X509 *x, size_t chainidx) 
{ 
    size_t expected_len = s->s3->previous_client_finished_len 
        + s->s3->previous_server_finished_len; 
    size_t ilen; 
    const unsigned char *data; 
 
    /* Check for logic errors */ 
    if (!ossl_assert(expected_len == 0 
                     || s->s3->previous_client_finished_len != 0) 
        || !ossl_assert(expected_len == 0 
                        || s->s3->previous_server_finished_len != 0)) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_RENEGOTIATE, 
                 ERR_R_INTERNAL_ERROR); 
        return 0; 
    } 
 
    /* Parse the length byte */ 
    if (!PACKET_get_1_len(pkt, &ilen)) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_RENEGOTIATE, 
                 SSL_R_RENEGOTIATION_ENCODING_ERR); 
        return 0; 
    } 
 
    /* Consistency check */ 
    if (PACKET_remaining(pkt) != ilen) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_RENEGOTIATE, 
                 SSL_R_RENEGOTIATION_ENCODING_ERR); 
        return 0; 
    } 
 
    /* Check that the extension matches */ 
    if (ilen != expected_len) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_RENEGOTIATE, 
                 SSL_R_RENEGOTIATION_MISMATCH); 
        return 0; 
    } 
 
    if (!PACKET_get_bytes(pkt, &data, s->s3->previous_client_finished_len) 
        || memcmp(data, s->s3->previous_client_finished, 
                  s->s3->previous_client_finished_len) != 0) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_RENEGOTIATE, 
                 SSL_R_RENEGOTIATION_MISMATCH); 
        return 0; 
    } 
 
    if (!PACKET_get_bytes(pkt, &data, s->s3->previous_server_finished_len) 
        || memcmp(data, s->s3->previous_server_finished, 
                  s->s3->previous_server_finished_len) != 0) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_RENEGOTIATE, 
                 SSL_R_RENEGOTIATION_MISMATCH); 
        return 0; 
    } 
    s->s3->send_connection_binding = 1; 
 
    return 1; 
} 
 
/* Parse the server's max fragment len extension packet */ 
int tls_parse_stoc_maxfragmentlen(SSL *s, PACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    unsigned int value; 
 
    if (PACKET_remaining(pkt) != 1 || !PACKET_get_1(pkt, &value)) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_MAXFRAGMENTLEN, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    /* |value| should contains a valid max-fragment-length code. */ 
    if (!IS_MAX_FRAGMENT_LENGTH_EXT_VALID(value)) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, 
                 SSL_F_TLS_PARSE_STOC_MAXFRAGMENTLEN, 
                 SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH); 
        return 0; 
    } 
 
    /* Must be the same value as client-configured one who was sent to server */ 
    /*- 
     * RFC 6066: if a client receives a maximum fragment length negotiation 
     * response that differs from the length it requested, ... 
     * It must abort with SSL_AD_ILLEGAL_PARAMETER alert 
     */ 
    if (value != s->ext.max_fragment_len_mode) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, 
                 SSL_F_TLS_PARSE_STOC_MAXFRAGMENTLEN, 
                 SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH); 
        return 0; 
    } 
 
    /* 
     * Maximum Fragment Length Negotiation succeeded. 
     * The negotiated Maximum Fragment Length is binding now. 
     */ 
    s->session->ext.max_fragment_len_mode = value; 
 
    return 1; 
} 
 
int tls_parse_stoc_server_name(SSL *s, PACKET *pkt, unsigned int context, 
                               X509 *x, size_t chainidx) 
{ 
    if (s->ext.hostname == NULL) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_SERVER_NAME, 
                 ERR_R_INTERNAL_ERROR); 
        return 0; 
    } 
 
    if (PACKET_remaining(pkt) > 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_SERVER_NAME, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    if (!s->hit) { 
        if (s->session->ext.hostname != NULL) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_SERVER_NAME, 
                     ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
        s->session->ext.hostname = OPENSSL_strdup(s->ext.hostname); 
        if (s->session->ext.hostname == NULL) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_SERVER_NAME, 
                     ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
    } 
 
    return 1; 
} 
 
#ifndef OPENSSL_NO_EC 
int tls_parse_stoc_ec_pt_formats(SSL *s, PACKET *pkt, unsigned int context, 
                                 X509 *x, size_t chainidx) 
{ 
    size_t ecpointformats_len; 
    PACKET ecptformatlist; 
 
    if (!PACKET_as_length_prefixed_1(pkt, &ecptformatlist)) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_EC_PT_FORMATS, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
    if (!s->hit) { 
        ecpointformats_len = PACKET_remaining(&ecptformatlist); 
        if (ecpointformats_len == 0) { 
            SSLfatal(s, SSL_AD_DECODE_ERROR, 
                     SSL_F_TLS_PARSE_STOC_EC_PT_FORMATS, SSL_R_BAD_LENGTH); 
            return 0; 
        } 
 
        s->ext.peer_ecpointformats_len = 0;
        OPENSSL_free(s->ext.peer_ecpointformats);
        s->ext.peer_ecpointformats = OPENSSL_malloc(ecpointformats_len);
        if (s->ext.peer_ecpointformats == NULL) {
            s->ext.peer_ecpointformats_len = 0;
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_PARSE_STOC_EC_PT_FORMATS, ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
 
        s->ext.peer_ecpointformats_len = ecpointformats_len;
 
        if (!PACKET_copy_bytes(&ecptformatlist, 
                               s->ext.peer_ecpointformats,
                               ecpointformats_len)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, 
                     SSL_F_TLS_PARSE_STOC_EC_PT_FORMATS, ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
    } 
 
    return 1; 
} 
#endif 
 
int tls_parse_stoc_session_ticket(SSL *s, PACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    if (s->ext.session_ticket_cb != NULL && 
        !s->ext.session_ticket_cb(s, PACKET_data(pkt), 
                              PACKET_remaining(pkt), 
                              s->ext.session_ticket_cb_arg)) { 
        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, 
                 SSL_F_TLS_PARSE_STOC_SESSION_TICKET, SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    if (!tls_use_ticket(s)) { 
        SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION, 
                 SSL_F_TLS_PARSE_STOC_SESSION_TICKET, SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
    if (PACKET_remaining(pkt) > 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, 
                 SSL_F_TLS_PARSE_STOC_SESSION_TICKET, SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    s->ext.ticket_expected = 1; 
 
    return 1; 
} 
 
#ifndef OPENSSL_NO_OCSP 
int tls_parse_stoc_status_request(SSL *s, PACKET *pkt, unsigned int context, 
                                  X509 *x, size_t chainidx) 
{ 
    if (context == SSL_EXT_TLS1_3_CERTIFICATE_REQUEST) { 
        /* We ignore this if the server sends a CertificateRequest */ 
        /* TODO(TLS1.3): Add support for this */ 
        return 1; 
    } 
 
    /* 
     * MUST only be sent if we've requested a status 
     * request message. In TLS <= 1.2 it must also be empty. 
     */ 
    if (s->ext.status_type != TLSEXT_STATUSTYPE_ocsp) { 
        SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION, 
                 SSL_F_TLS_PARSE_STOC_STATUS_REQUEST, SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
    if (!SSL_IS_TLS13(s) && PACKET_remaining(pkt) > 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, 
                 SSL_F_TLS_PARSE_STOC_STATUS_REQUEST, SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    if (SSL_IS_TLS13(s)) { 
        /* We only know how to handle this if it's for the first Certificate in 
         * the chain. We ignore any other responses. 
         */ 
        if (chainidx != 0) 
            return 1; 
 
        /* SSLfatal() already called */ 
        return tls_process_cert_status_body(s, pkt); 
    } 
 
    /* Set flag to expect CertificateStatus message */ 
    s->ext.status_expected = 1; 
 
    return 1; 
} 
#endif 
 
 
#ifndef OPENSSL_NO_CT 
int tls_parse_stoc_sct(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                       size_t chainidx) 
{ 
    if (context == SSL_EXT_TLS1_3_CERTIFICATE_REQUEST) { 
        /* We ignore this if the server sends it in a CertificateRequest */ 
        /* TODO(TLS1.3): Add support for this */ 
        return 1; 
    } 
 
    /* 
     * Only take it if we asked for it - i.e if there is no CT validation 
     * callback set, then a custom extension MAY be processing it, so we 
     * need to let control continue to flow to that. 
     */ 
    if (s->ct_validation_callback != NULL) { 
        size_t size = PACKET_remaining(pkt); 
 
        /* Simply copy it off for later processing */ 
        OPENSSL_free(s->ext.scts); 
        s->ext.scts = NULL; 
 
        s->ext.scts_len = (uint16_t)size; 
        if (size > 0) { 
            s->ext.scts = OPENSSL_malloc(size); 
            if (s->ext.scts == NULL) {
                s->ext.scts_len = 0;
                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_SCT, 
                         ERR_R_MALLOC_FAILURE);
                return 0;
            }
            if (!PACKET_copy_bytes(pkt, s->ext.scts, size)) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_SCT,
                         ERR_R_INTERNAL_ERROR); 
                return 0; 
            } 
        } 
    } else { 
        ENDPOINT role = (context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0 
                        ? ENDPOINT_CLIENT : ENDPOINT_BOTH; 
 
        /* 
         * If we didn't ask for it then there must be a custom extension, 
         * otherwise this is unsolicited. 
         */ 
        if (custom_ext_find(&s->cert->custext, role, 
                            TLSEXT_TYPE_signed_certificate_timestamp, 
                            NULL) == NULL) { 
            SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_F_TLS_PARSE_STOC_SCT, 
                     SSL_R_BAD_EXTENSION); 
            return 0; 
        } 
 
        if (!custom_ext_parse(s, context, 
                             TLSEXT_TYPE_signed_certificate_timestamp, 
                             PACKET_data(pkt), PACKET_remaining(pkt), 
                             x, chainidx)) { 
            /* SSLfatal already called */ 
            return 0; 
        } 
    } 
 
    return 1; 
} 
#endif 
 
 
#ifndef OPENSSL_NO_NEXTPROTONEG 
/* 
 * ssl_next_proto_validate validates a Next Protocol Negotiation block. No 
 * elements of zero length are allowed and the set of elements must exactly 
 * fill the length of the block. Returns 1 on success or 0 on failure. 
 */ 
static int ssl_next_proto_validate(SSL *s, PACKET *pkt) 
{ 
    PACKET tmp_protocol; 
 
    while (PACKET_remaining(pkt)) { 
        if (!PACKET_get_length_prefixed_1(pkt, &tmp_protocol) 
            || PACKET_remaining(&tmp_protocol) == 0) { 
            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL_NEXT_PROTO_VALIDATE, 
                     SSL_R_BAD_EXTENSION); 
            return 0; 
        } 
    } 
 
    return 1; 
} 
 
int tls_parse_stoc_npn(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                       size_t chainidx) 
{ 
    unsigned char *selected; 
    unsigned char selected_len; 
    PACKET tmppkt; 
 
    /* Check if we are in a renegotiation. If so ignore this extension */ 
    if (!SSL_IS_FIRST_HANDSHAKE(s)) 
        return 1; 
 
    /* We must have requested it. */ 
    if (s->ctx->ext.npn_select_cb == NULL) { 
        SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION, SSL_F_TLS_PARSE_STOC_NPN, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    /* The data must be valid */ 
    tmppkt = *pkt; 
    if (!ssl_next_proto_validate(s, &tmppkt)) { 
        /* SSLfatal() already called */ 
        return 0; 
    } 
    if (s->ctx->ext.npn_select_cb(s, &selected, &selected_len, 
                                  PACKET_data(pkt), 
                                  PACKET_remaining(pkt), 
                                  s->ctx->ext.npn_select_cb_arg) != 
             SSL_TLSEXT_ERR_OK) { 
        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PARSE_STOC_NPN, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    /* 
     * Could be non-NULL if server has sent multiple NPN extensions in 
     * a single Serverhello 
     */ 
    OPENSSL_free(s->ext.npn); 
    s->ext.npn = OPENSSL_malloc(selected_len); 
    if (s->ext.npn == NULL) { 
        s->ext.npn_len = 0;
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_NPN, 
                 ERR_R_INTERNAL_ERROR); 
        return 0; 
    } 
 
    memcpy(s->ext.npn, selected, selected_len); 
    s->ext.npn_len = selected_len; 
    s->s3->npn_seen = 1; 
 
    return 1; 
} 
#endif 
 
int tls_parse_stoc_alpn(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                        size_t chainidx) 
{ 
    size_t len; 
 
    /* We must have requested it. */ 
    if (!s->s3->alpn_sent) { 
        SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION, SSL_F_TLS_PARSE_STOC_ALPN, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
    /*- 
     * The extension data consists of: 
     *   uint16 list_length 
     *   uint8 proto_length; 
     *   uint8 proto[proto_length]; 
     */ 
    if (!PACKET_get_net_2_len(pkt, &len) 
        || PACKET_remaining(pkt) != len || !PACKET_get_1_len(pkt, &len) 
        || PACKET_remaining(pkt) != len) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_ALPN, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
    OPENSSL_free(s->s3->alpn_selected); 
    s->s3->alpn_selected = OPENSSL_malloc(len); 
    if (s->s3->alpn_selected == NULL) { 
        s->s3->alpn_selected_len = 0;
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_ALPN, 
                 ERR_R_INTERNAL_ERROR); 
        return 0; 
    } 
    if (!PACKET_copy_bytes(pkt, s->s3->alpn_selected, len)) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_ALPN, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
    s->s3->alpn_selected_len = len; 
 
    if (s->session->ext.alpn_selected == NULL 
            || s->session->ext.alpn_selected_len != len 
            || memcmp(s->session->ext.alpn_selected, s->s3->alpn_selected, len) 
               != 0) { 
        /* ALPN not consistent with the old session so cannot use early_data */ 
        s->ext.early_data_ok = 0; 
    } 
    if (!s->hit) { 
        /* 
         * This is a new session and so alpn_selected should have been 
         * initialised to NULL. We should update it with the selected ALPN. 
         */ 
        if (!ossl_assert(s->session->ext.alpn_selected == NULL)) { 
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_ALPN, 
                     ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
        s->session->ext.alpn_selected = 
            OPENSSL_memdup(s->s3->alpn_selected, s->s3->alpn_selected_len); 
        if (s->session->ext.alpn_selected == NULL) { 
            s->session->ext.alpn_selected_len = 0;
            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_ALPN, 
                     ERR_R_INTERNAL_ERROR); 
            return 0; 
        } 
        s->session->ext.alpn_selected_len = s->s3->alpn_selected_len; 
    } 
 
    return 1; 
} 
 
#ifndef OPENSSL_NO_SRTP 
int tls_parse_stoc_use_srtp(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                            size_t chainidx) 
{ 
    unsigned int id, ct, mki; 
    int i; 
    STACK_OF(SRTP_PROTECTION_PROFILE) *clnt; 
    SRTP_PROTECTION_PROFILE *prof; 
 
    if (!PACKET_get_net_2(pkt, &ct) || ct != 2 
            || !PACKET_get_net_2(pkt, &id) 
            || !PACKET_get_1(pkt, &mki) 
            || PACKET_remaining(pkt) != 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_USE_SRTP, 
                 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 
        return 0; 
    } 
 
    if (mki != 0) { 
        /* Must be no MKI, since we never offer one */ 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_USE_SRTP, 
                 SSL_R_BAD_SRTP_MKI_VALUE); 
        return 0; 
    } 
 
    /* Throw an error if the server gave us an unsolicited extension */ 
    clnt = SSL_get_srtp_profiles(s); 
    if (clnt == NULL) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_USE_SRTP, 
                 SSL_R_NO_SRTP_PROFILES); 
        return 0; 
    } 
 
    /* 
     * Check to see if the server gave us something we support (and 
     * presumably offered) 
     */ 
    for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) { 
        prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i); 
 
        if (prof->id == id) { 
            s->srtp_profile = prof; 
            return 1; 
        } 
    } 
 
    SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_USE_SRTP, 
             SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 
    return 0; 
} 
#endif 
 
int tls_parse_stoc_etm(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                       size_t chainidx) 
{ 
    /* Ignore if inappropriate ciphersuite */ 
    if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC) 
            && s->s3->tmp.new_cipher->algorithm_mac != SSL_AEAD 
            && s->s3->tmp.new_cipher->algorithm_enc != SSL_RC4) 
        s->ext.use_etm = 1; 
 
    return 1; 
} 
 
int tls_parse_stoc_ems(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                       size_t chainidx) 
{ 
    s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS; 
    if (!s->hit) 
        s->session->flags |= SSL_SESS_FLAG_EXTMS; 
 
    return 1; 
} 
 
int tls_parse_stoc_supported_versions(SSL *s, PACKET *pkt, unsigned int context, 
                                      X509 *x, size_t chainidx) 
{ 
    unsigned int version; 
 
    if (!PACKET_get_net_2(pkt, &version) 
            || PACKET_remaining(pkt) != 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, 
                 SSL_F_TLS_PARSE_STOC_SUPPORTED_VERSIONS, 
                 SSL_R_LENGTH_MISMATCH); 
        return 0; 
    } 
 
    /* 
     * The only protocol version we support which is valid in this extension in 
     * a ServerHello is TLSv1.3 therefore we shouldn't be getting anything else. 
     */ 
    if (version != TLS1_3_VERSION) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, 
                 SSL_F_TLS_PARSE_STOC_SUPPORTED_VERSIONS, 
                 SSL_R_BAD_PROTOCOL_VERSION_NUMBER); 
        return 0; 
    } 
 
    /* We ignore this extension for HRRs except to sanity check it */ 
    if (context == SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) 
        return 1; 
 
    /* We just set it here. We validate it in ssl_choose_client_version */ 
    s->version = version; 
 
    return 1; 
} 
 
int tls_parse_stoc_key_share(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                             size_t chainidx) 
{ 
#ifndef OPENSSL_NO_TLS1_3 
    unsigned int group_id; 
    PACKET encoded_pt; 
    EVP_PKEY *ckey = s->s3->tmp.pkey, *skey = NULL; 
 
    /* Sanity check */ 
    if (ckey == NULL || s->s3->peer_tmp != NULL) { 
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                 ERR_R_INTERNAL_ERROR); 
        return 0; 
    } 
 
    if (!PACKET_get_net_2(pkt, &group_id)) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                 SSL_R_LENGTH_MISMATCH); 
        return 0; 
    } 
 
    if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0) { 
        const uint16_t *pgroups = NULL; 
        size_t i, num_groups; 
 
        if (PACKET_remaining(pkt) != 0) { 
            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                     SSL_R_LENGTH_MISMATCH); 
            return 0; 
        } 
 
        /* 
         * It is an error if the HelloRetryRequest wants a key_share that we 
         * already sent in the first ClientHello 
         */ 
        if (group_id == s->s3->group_id) { 
            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, 
                     SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_KEY_SHARE); 
            return 0; 
        } 
 
        /* Validate the selected group is one we support */ 
        tls1_get_supported_groups(s, &pgroups, &num_groups); 
        for (i = 0; i < num_groups; i++) { 
            if (group_id == pgroups[i]) 
                break; 
        } 
        if (i >= num_groups 
                || !tls_curve_allowed(s, group_id, SSL_SECOP_CURVE_SUPPORTED)) { 
            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, 
                     SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_KEY_SHARE); 
            return 0; 
        } 
 
        s->s3->group_id = group_id; 
        EVP_PKEY_free(s->s3->tmp.pkey); 
        s->s3->tmp.pkey = NULL; 
        return 1; 
    } 
 
    if (group_id != s->s3->group_id) { 
        /* 
         * This isn't for the group that we sent in the original 
         * key_share! 
         */ 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                 SSL_R_BAD_KEY_SHARE); 
        return 0; 
    } 
 
    if (!PACKET_as_length_prefixed_2(pkt, &encoded_pt) 
            || PACKET_remaining(&encoded_pt) == 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                 SSL_R_LENGTH_MISMATCH); 
        return 0; 
    } 
 
    skey = EVP_PKEY_new();
    if (skey == NULL || EVP_PKEY_copy_parameters(skey, ckey) <= 0) {
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                 ERR_R_MALLOC_FAILURE); 
        return 0; 
    } 
    if (!EVP_PKEY_set1_tls_encodedpoint(skey, PACKET_data(&encoded_pt), 
                                        PACKET_remaining(&encoded_pt))) { 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_KEY_SHARE, 
                 SSL_R_BAD_ECPOINT); 
        EVP_PKEY_free(skey); 
        return 0; 
    } 
 
    if (ssl_derive(s, ckey, skey, 1) == 0) { 
        /* SSLfatal() already called */ 
        EVP_PKEY_free(skey); 
        return 0; 
    } 
    s->s3->peer_tmp = skey; 
#endif 
 
    return 1; 
} 
 
int tls_parse_stoc_cookie(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                       size_t chainidx) 
{ 
    PACKET cookie; 
 
    if (!PACKET_as_length_prefixed_2(pkt, &cookie) 
            || !PACKET_memdup(&cookie, &s->ext.tls13_cookie, 
                              &s->ext.tls13_cookie_len)) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_COOKIE, 
                 SSL_R_LENGTH_MISMATCH); 
        return 0; 
    } 
 
    return 1; 
} 
 
int tls_parse_stoc_early_data(SSL *s, PACKET *pkt, unsigned int context, 
                              X509 *x, size_t chainidx) 
{ 
    if (context == SSL_EXT_TLS1_3_NEW_SESSION_TICKET) { 
        unsigned long max_early_data; 
 
        if (!PACKET_get_net_4(pkt, &max_early_data) 
                || PACKET_remaining(pkt) != 0) { 
            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_EARLY_DATA, 
                     SSL_R_INVALID_MAX_EARLY_DATA); 
            return 0; 
        } 
 
        s->session->ext.max_early_data = max_early_data; 
 
        return 1; 
    } 
 
    if (PACKET_remaining(pkt) != 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_EARLY_DATA, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    if (!s->ext.early_data_ok 
            || !s->hit) {
        /* 
         * If we get here then we didn't send early data, or we didn't resume 
         * using the first identity, or the SNI/ALPN is not consistent so the 
         * server should not be accepting it. 
         */ 
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_EARLY_DATA, 
                 SSL_R_BAD_EXTENSION); 
        return 0; 
    } 
 
    s->ext.early_data = SSL_EARLY_DATA_ACCEPTED; 
 
    return 1; 
} 
 
int tls_parse_stoc_psk(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 
                       size_t chainidx) 
{ 
#ifndef OPENSSL_NO_TLS1_3 
    unsigned int identity; 
 
    if (!PACKET_get_net_2(pkt, &identity) || PACKET_remaining(pkt) != 0) { 
        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_PSK, 
                 SSL_R_LENGTH_MISMATCH); 
        return 0; 
    } 
 
    if (identity >= (unsigned int)s->ext.tick_identity) {
        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_PSK,
                 SSL_R_BAD_PSK_IDENTITY);
        return 0;
    }

    /*
     * Session resumption tickets are always sent before PSK tickets. If the
     * ticket index is 0 then it must be for a session resumption ticket if we
     * sent two tickets, or if we didn't send a PSK ticket.
     */
    if (identity == 0 && (s->psksession == NULL || s->ext.tick_identity == 2)) {
        s->hit = 1; 
        SSL_SESSION_free(s->psksession); 
        s->psksession = NULL; 
        return 1; 
    } 
 
    if (s->psksession == NULL) {
        /* Should never happen */
        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_PSK,
                 ERR_R_INTERNAL_ERROR);
        return 0; 
    } 
 
    /* 
     * If we used the external PSK for sending early_data then s->early_secret 
     * is already set up, so don't overwrite it. Otherwise we copy the 
     * early_secret across that we generated earlier. 
     */ 
    if ((s->early_data_state != SSL_EARLY_DATA_WRITE_RETRY 
                && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING) 
            || s->session->ext.max_early_data > 0 
            || s->psksession->ext.max_early_data == 0) 
        memcpy(s->early_secret, s->psksession->early_secret, EVP_MAX_MD_SIZE); 
 
    SSL_SESSION_free(s->session); 
    s->session = s->psksession; 
    s->psksession = NULL; 
    s->hit = 1; 
    /* Early data is only allowed if we used the first ticket */
    if (identity != 0)
        s->ext.early_data_ok = 0;
#endif 
 
    return 1; 
}