int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
{
    if (!ossl_assert(pkt->subs != NULL && len != 0))
        return 0;
    if (pkt->maxsize - pkt->written < len)
        return 0;
    if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) {
        size_t newlen;
        size_t reflen;
        reflen = (len > pkt->buf->length) ? len : pkt->buf->length;
        if (reflen > SIZE_MAX / 2) {
            newlen = SIZE_MAX;
        } else {
            newlen = reflen * 2;
            if (newlen < DEFAULT_BUF_SIZE)
                newlen = DEFAULT_BUF_SIZE;
        }
        if (BUF_MEM_grow(pkt->buf, newlen) == 0)
            return 0;
    }
    if (allocbytes != NULL)
        *allocbytes = WPACKET_get_curr(pkt);
    return 1;
}
['int tls_construct_certificate_request(SSL *s, WPACKET *pkt)\n{\n    if (SSL_IS_TLS13(s)) {\n        if (s->post_handshake_auth == SSL_PHA_REQUEST_PENDING) {\n            OPENSSL_free(s->pha_context);\n            s->pha_context_len = 32;\n            if ((s->pha_context = OPENSSL_malloc(s->pha_context_len)) == NULL\n                    || ssl_randbytes(s, s->pha_context, s->pha_context_len) <= 0\n                    || !WPACKET_sub_memcpy_u8(pkt, s->pha_context, s->pha_context_len)) {\n                SSLfatal(s, SSL_AD_INTERNAL_ERROR,\n                         SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST,\n                         ERR_R_INTERNAL_ERROR);\n                return 0;\n            }\n            if (!tls13_restore_handshake_digest_for_pha(s)) {\n                return 0;\n            }\n        } else {\n            if (!WPACKET_put_bytes_u8(pkt, 0)) {\n                SSLfatal(s, SSL_AD_INTERNAL_ERROR,\n                         SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST,\n                         ERR_R_INTERNAL_ERROR);\n                return 0;\n            }\n        }\n        if (!tls_construct_extensions(s, pkt,\n                                      SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, NULL,\n                                      0)) {\n            return 0;\n        }\n        goto done;\n    }\n    if (!WPACKET_start_sub_packet_u8(pkt)\n        || !ssl3_get_req_cert_type(s, pkt) || !WPACKET_close(pkt)) {\n        SSLfatal(s, SSL_AD_INTERNAL_ERROR,\n                 SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST, ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\n    if (SSL_USE_SIGALGS(s)) {\n        const uint16_t *psigs;\n        size_t nl = tls12_get_psigalgs(s, 1, &psigs);\n        if (!WPACKET_start_sub_packet_u16(pkt)\n                || !WPACKET_set_flags(pkt, WPACKET_FLAGS_NON_ZERO_LENGTH)\n                || !tls12_copy_sigalgs(s, pkt, psigs, nl)\n                || !WPACKET_close(pkt)) {\n            SSLfatal(s, SSL_AD_INTERNAL_ERROR,\n                     SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST,\n                     ERR_R_INTERNAL_ERROR);\n            return 0;\n        }\n    }\n    if (!construct_ca_names(s, pkt)) {\n        return 0;\n    }\n done:\n    s->certreqs_sent++;\n    s->s3->tmp.cert_request = 1;\n    return 1;\n}', 'int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,\n                         size_t lenbytes)\n{\n    if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)\n            || !WPACKET_memcpy(pkt, src, len)\n            || !WPACKET_close(pkt))\n        return 0;\n    return 1;\n}', 'int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes)\n{\n    WPACKET_SUB *sub;\n    unsigned char *lenchars;\n    if (!ossl_assert(pkt->subs != NULL))\n        return 0;\n    sub = OPENSSL_zalloc(sizeof(*sub));\n    if (sub == NULL)\n        return 0;\n    sub->parent = pkt->subs;\n    pkt->subs = sub;\n    sub->pwritten = pkt->written + lenbytes;\n    sub->lenbytes = lenbytes;\n    if (lenbytes == 0) {\n        sub->packet_len = 0;\n        return 1;\n    }\n    if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars))\n        return 0;\n    sub->packet_len = lenchars - GETBUF(pkt);\n    return 1;\n}', 'int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)\n{\n    unsigned char *dest;\n    if (len == 0)\n        return 1;\n    if (!WPACKET_allocate_bytes(pkt, len, &dest))\n        return 0;\n    memcpy(dest, src, len);\n    return 1;\n}', 'int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)\n{\n    if (!WPACKET_reserve_bytes(pkt, len, allocbytes))\n        return 0;\n    pkt->written += len;\n    pkt->curr += len;\n    return 1;\n}', 'int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)\n{\n    if (!ossl_assert(pkt->subs != NULL && len != 0))\n        return 0;\n    if (pkt->maxsize - pkt->written < len)\n        return 0;\n    if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) {\n        size_t newlen;\n        size_t reflen;\n        reflen = (len > pkt->buf->length) ? len : pkt->buf->length;\n        if (reflen > SIZE_MAX / 2) {\n            newlen = SIZE_MAX;\n        } else {\n            newlen = reflen * 2;\n            if (newlen < DEFAULT_BUF_SIZE)\n                newlen = DEFAULT_BUF_SIZE;\n        }\n        if (BUF_MEM_grow(pkt->buf, newlen) == 0)\n            return 0;\n    }\n    if (allocbytes != NULL)\n        *allocbytes = WPACKET_get_curr(pkt);\n    return 1;\n}']