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;
}
['static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,\n                                                        unsigned int context,\n                                                        X509 *x,\n                                                        size_t chainidx)\n{\n    const STACK_OF(X509_NAME) *ca_sk = get_ca_names(s);\n    if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)\n        return EXT_RETURN_NOT_SENT;\n    if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)\n        || !WPACKET_start_sub_packet_u16(pkt)) {\n        SSLfatal(s, SSL_AD_INTERNAL_ERROR,\n                 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,\n               ERR_R_INTERNAL_ERROR);\n        return EXT_RETURN_FAIL;\n    }\n    if (!construct_ca_names(s, ca_sk, pkt)) {\n        return EXT_RETURN_FAIL;\n    }\n    if (!WPACKET_close(pkt)) {\n        SSLfatal(s, SSL_AD_INTERNAL_ERROR,\n                 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,\n                 ERR_R_INTERNAL_ERROR);\n        return EXT_RETURN_FAIL;\n    }\n    return EXT_RETURN_SENT;\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    if ((sub = OPENSSL_zalloc(sizeof(*sub))) == NULL) {\n        SSLerr(SSL_F_WPACKET_START_SUB_PACKET_LEN__, ERR_R_MALLOC_FAILURE);\n        return 0;\n    }\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 construct_ca_names(SSL *s, const STACK_OF(X509_NAME) *ca_sk, WPACKET *pkt)\n{\n    if (!WPACKET_start_sub_packet_u16(pkt)) {\n        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_CA_NAMES,\n                 ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\n    if (ca_sk != NULL) {\n        int i;\n        for (i = 0; i < sk_X509_NAME_num(ca_sk); i++) {\n            unsigned char *namebytes;\n            X509_NAME *name = sk_X509_NAME_value(ca_sk, i);\n            int namelen;\n            if (name == NULL\n                    || (namelen = i2d_X509_NAME(name, NULL)) < 0\n                    || !WPACKET_sub_allocate_bytes_u16(pkt, namelen,\n                                                       &namebytes)\n                    || i2d_X509_NAME(name, &namebytes) != namelen) {\n                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_CA_NAMES,\n                         ERR_R_INTERNAL_ERROR);\n                return 0;\n            }\n        }\n    }\n    if (!WPACKET_close(pkt)) {\n        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_CA_NAMES,\n                 ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\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}']