int WPACKET_reserve_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;
        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;
    }
    *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr;
    return 1;
}
['static int tls_construct_cke_rsa(SSL *s, WPACKET *pkt, int *al)\n{\n#ifndef OPENSSL_NO_RSA\n    unsigned char *encdata = NULL;\n    EVP_PKEY *pkey = NULL;\n    EVP_PKEY_CTX *pctx = NULL;\n    size_t enclen;\n    unsigned char *pms = NULL;\n    size_t pmslen = 0;\n    if (s->session->peer == NULL) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\n    pkey = X509_get0_pubkey(s->session->peer);\n    if (EVP_PKEY_get0_RSA(pkey) == NULL) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\n    pmslen = SSL_MAX_MASTER_KEY_LENGTH;\n    pms = OPENSSL_malloc(pmslen);\n    if (pms == NULL) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_MALLOC_FAILURE);\n        *al = SSL_AD_INTERNAL_ERROR;\n        return 0;\n    }\n    pms[0] = s->client_version >> 8;\n    pms[1] = s->client_version & 0xff;\n    if (RAND_bytes(pms + 2, pmslen - 2) <= 0) {\n        goto err;\n    }\n    if (s->version > SSL3_VERSION && !WPACKET_start_sub_packet_u16(pkt)) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);\n        goto err;\n    }\n    pctx = EVP_PKEY_CTX_new(pkey, NULL);\n    if (pctx == NULL || EVP_PKEY_encrypt_init(pctx) <= 0\n        || EVP_PKEY_encrypt(pctx, NULL, &enclen, pms, pmslen) <= 0) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_EVP_LIB);\n        goto err;\n    }\n    if (!WPACKET_allocate_bytes(pkt, enclen, &encdata)\n            || EVP_PKEY_encrypt(pctx, encdata, &enclen, pms, pmslen) <= 0) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, SSL_R_BAD_RSA_ENCRYPT);\n        goto err;\n    }\n    EVP_PKEY_CTX_free(pctx);\n    pctx = NULL;\n# ifdef PKCS1_CHECK\n    if (s->options & SSL_OP_PKCS1_CHECK_1)\n        (*p)[1]++;\n    if (s->options & SSL_OP_PKCS1_CHECK_2)\n        tmp_buf[0] = 0x70;\n# endif\n    if (s->version > SSL3_VERSION && !WPACKET_close(pkt)) {\n        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);\n        goto err;\n    }\n    s->s3->tmp.pms = pms;\n    s->s3->tmp.pmslen = pmslen;\n    return 1;\n err:\n    OPENSSL_clear_free(pms, pmslen);\n    EVP_PKEY_CTX_free(pctx);\n    return 0;\n#else\n    SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);\n    *al = SSL_AD_INTERNAL_ERROR;\n    return 0;\n#endif\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    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        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    *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr;\n    return 1;\n}']