int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
{
    assert(pkt->subs != NULL && len != 0);
    if (pkt->subs == NULL || len == 0)
        return 0;
    if (pkt->maxsize - pkt->written < len)
        return 0;
    if (pkt->buf->length - pkt->written < len) {
        size_t newlen;
        if (pkt->buf->length > SIZE_MAX / 2) {
            newlen = SIZE_MAX;
        } else {
            newlen = (pkt->buf->length == 0) ? DEFAULT_BUF_SIZE
                                             : pkt->buf->length * 2;
        }
        if (BUF_MEM_grow(pkt->buf, newlen) == 0)
            return 0;
    }
    *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr;
    pkt->written += len;
    pkt->curr += len;
    return 1;
}
['static int tls_construct_cke_ecdhe(SSL *s, WPACKET *pkt, int *al)\n{\n#ifndef OPENSSL_NO_EC\n    unsigned char *encodedPoint = NULL;\n    int encoded_pt_len = 0;\n    EVP_PKEY *ckey = NULL, *skey = NULL;\n    int ret = 0;\n    skey = s->s3->peer_tmp;\n    if (skey == NULL) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\n    ckey = ssl_generate_pkey(skey);\n    if (ssl_derive(s, ckey, skey) == 0) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_EVP_LIB);\n        goto err;\n    }\n    encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(ckey, &encodedPoint);\n    if (encoded_pt_len == 0) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_EC_LIB);\n        goto err;\n    }\n    if (!WPACKET_sub_memcpy_u8(pkt, encodedPoint, encoded_pt_len)) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_INTERNAL_ERROR);\n        goto err;\n    }\n    ret = 1;\n err:\n    OPENSSL_free(encodedPoint);\n    EVP_PKEY_free(ckey);\n    return ret;\n#else\n    SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_INTERNAL_ERROR);\n    *al = SSL_AD_INTERNAL_ERROR;\n    return 0;\n#endif\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    assert(pkt->subs != NULL);\n    if (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 - (unsigned char *)pkt->buf->data;\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    assert(pkt->subs != NULL && len != 0);\n    if (pkt->subs == NULL || len == 0)\n        return 0;\n    if (pkt->maxsize - pkt->written < len)\n        return 0;\n    if (pkt->buf->length - pkt->written < len) {\n        size_t newlen;\n        if (pkt->buf->length > SIZE_MAX / 2) {\n            newlen = SIZE_MAX;\n        } else {\n            newlen = (pkt->buf->length == 0) ? DEFAULT_BUF_SIZE\n                                             : pkt->buf->length * 2;\n        }\n        if (BUF_MEM_grow(pkt->buf, newlen) == 0)\n            return 0;\n    }\n    *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr;\n    pkt->written += len;\n    pkt->curr += len;\n    return 1;\n}']