int ASN1_mbstring_ncopy(ASN1_STRING **out, const unsigned char *in, int len,
                        int inform, unsigned long mask,
                        long minsize, long maxsize)
{
    int str_type;
    int ret;
    char free_out;
    int outform, outlen = 0;
    ASN1_STRING *dest;
    unsigned char *p;
    int nchar;
    char strbuf[32];
    int (*cpyfunc) (unsigned long, void *) = NULL;
    if (len == -1)
        len = strlen((const char *)in);
    if (!mask)
        mask = DIRSTRING_TYPE;

    /* First do a string check and work out the number of characters */
    switch (inform) {

    case MBSTRING_BMP:
        if (len & 1) {
            ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY,
                    ASN1_R_INVALID_BMPSTRING_LENGTH);
            return -1;
        }
        nchar = len >> 1;
        break;

    case MBSTRING_UNIV:
        if (len & 3) {
            ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY,
                    ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
            return -1;
        }
        nchar = len >> 2;
        break;

    case MBSTRING_UTF8:
        nchar = 0;
        /* This counts the characters and does utf8 syntax checking */
        ret = traverse_string(in, len, MBSTRING_UTF8, in_utf8, &nchar);
        if (ret < 0) {
            ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ASN1_R_INVALID_UTF8STRING);
            return -1;
        }
        break;

    case MBSTRING_ASC:
        nchar = len;
        break;

    default:
        ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ASN1_R_UNKNOWN_FORMAT);
        return -1;
    }

    if ((minsize > 0) && (nchar < minsize)) {
        ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ASN1_R_STRING_TOO_SHORT);
        sprintf(strbuf, "%ld", minsize);
        ERR_add_error_data(2, "minsize=", strbuf);
        return -1;
    }

    if ((maxsize > 0) && (nchar > maxsize)) {
        ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ASN1_R_STRING_TOO_LONG);
        sprintf(strbuf, "%ld", maxsize);
        ERR_add_error_data(2, "maxsize=", strbuf);
        return -1;
    }

    /* Now work out minimal type (if any) */
    if (traverse_string(in, len, inform, type_str, &mask) < 0) {
        ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ASN1_R_ILLEGAL_CHARACTERS);
        return -1;
    }

    /* Now work out output format and string type */
    outform = MBSTRING_ASC;
    if (mask & B_ASN1_NUMERICSTRING)
        str_type = V_ASN1_NUMERICSTRING;
    else if (mask & B_ASN1_PRINTABLESTRING)
        str_type = V_ASN1_PRINTABLESTRING;
    else if (mask & B_ASN1_IA5STRING)
        str_type = V_ASN1_IA5STRING;
    else if (mask & B_ASN1_T61STRING)
        str_type = V_ASN1_T61STRING;
    else if (mask & B_ASN1_BMPSTRING) {
        str_type = V_ASN1_BMPSTRING;
        outform = MBSTRING_BMP;
    } else if (mask & B_ASN1_UNIVERSALSTRING) {
        str_type = V_ASN1_UNIVERSALSTRING;
        outform = MBSTRING_UNIV;
    } else {
        str_type = V_ASN1_UTF8STRING;
        outform = MBSTRING_UTF8;
    }
    if (!out)
        return str_type;
    if (*out) {
        free_out = 0;
        dest = *out;
        OPENSSL_free(dest->data);
        dest->data = NULL;
        dest->length = 0;
        dest->type = str_type;
    } else {
        free_out = 1;
        dest = ASN1_STRING_type_new(str_type);
        if (dest == NULL) {
            ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ERR_R_MALLOC_FAILURE);
            return -1;
        }
        *out = dest;
    }
    /* If both the same type just copy across */
    if (inform == outform) {
        if (!ASN1_STRING_set(dest, in, len)) {
            ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ERR_R_MALLOC_FAILURE);
            return -1;
        }
        return str_type;
    }

    /* Work out how much space the destination will need */
    switch (outform) {
    case MBSTRING_ASC:
        outlen = nchar;
        cpyfunc = cpy_asc;
        break;

    case MBSTRING_BMP:
        outlen = nchar << 1;
        cpyfunc = cpy_bmp;
        break;

    case MBSTRING_UNIV:
        outlen = nchar << 2;
        cpyfunc = cpy_univ;
        break;

    case MBSTRING_UTF8:
        outlen = 0;
        traverse_string(in, len, inform, out_utf8, &outlen);
        cpyfunc = cpy_utf8;
        break;
    }
    if ((p = OPENSSL_malloc(outlen + 1)) == NULL) {
        if (free_out)
            ASN1_STRING_free(dest);
        ASN1err(ASN1_F_ASN1_MBSTRING_NCOPY, ERR_R_MALLOC_FAILURE);
        return -1;
    }
    dest->length = outlen;
    dest->data = p;
    p[outlen] = 0;
    traverse_string(in, len, inform, cpyfunc, &p);
    return str_type;
}