/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <string.h>

#include "secitem.h"

#include "secport.h"

#include "secerr.h"

/* if to->data is not NULL, and to->len is large enough to hold the result,

 * then the resultant OID will be copyed into to->data, and to->len will be

 * changed to show the actual OID length.

 * Otherwise, memory for the OID will be allocated (from the caller's

 * PLArenaPool, if pool is non-NULL) and to->data will receive the address

 * of the allocated data, and to->len will receive the OID length.

 * The original value of to->data is not freed when a new buffer is allocated.

 *

 * The input string may begin with "OID." and this still be ignored.

 * The length of the input string is given in len.  If len == 0, then

 * len will be computed as strlen(from), meaning it must be NUL terminated.

 * It is an error if from == NULL, or if *from == '\0'.

 */

SECStatus

SEC_StringToOID(PLArenaPool *pool, SECItem *to, const char *from, PRUint32 len)

{

    PRUint32 decimal_numbers = 0;

    PRUint32 result_bytes = 0;

    SECStatus rv;

    PRUint8 result[1024];

    static const PRUint32 max_decimal = (0xffffffff / 10);

    static const char OIDstring[] = { "OID." };

    if (!from || !to) {

        PORT_SetError(SEC_ERROR_INVALID_ARGS);

        return SECFailure;

    }

    if (!len) {

        len = PL_strlen(from);

    }

    if (len >= 4 && !PL_strncasecmp(from, OIDstring, 4)) {

        from += 4; /* skip leading "OID." if present */

        len -= 4;

    }

    if (!len) {

    bad_data:

        PORT_SetError(SEC_ERROR_BAD_DATA);

        return SECFailure;

    }

    do {

        PRUint32 decimal = 0;

        while (len > 0 && isdigit((unsigned char)*from)) {

            PRUint32 addend = (*from++ - '0');

            --len;

            if (decimal > max_decimal) /* overflow */

                goto bad_data;

            decimal = (decimal * 10) + addend;

            if (decimal < addend) /* overflow */

                goto bad_data;

        }

        if (len != 0 && *from != '.') {

            goto bad_data;

        }

        if (decimal_numbers == 0) {

            if (decimal > 2)

                goto bad_data;

            result[0] = decimal * 40;

            result_bytes = 1;

        } else if (decimal_numbers == 1) {

            if (decimal > 40)

                goto bad_data;

            result[0] += decimal;

        } else {

            /* encode the decimal number,  */

            PRUint8 *rp;

            PRUint32 num_bytes = 0;

            PRUint32 tmp = decimal;

            while (tmp) {

                num_bytes++;

                tmp >>= 7;

            }

            if (!num_bytes)

                ++num_bytes; /* use one byte for a zero value */

            if (num_bytes + result_bytes > sizeof result)

                goto bad_data;

            tmp = num_bytes;

            rp = result + result_bytes - 1;

            rp[tmp] = (PRUint8)(decimal & 0x7f);

            decimal >>= 7;

            while (--tmp > 0) {

                rp[tmp] = (PRUint8)(decimal | 0x80);

                decimal >>= 7;

            }

            result_bytes += num_bytes;

        }

        ++decimal_numbers;

        if (len > 0) { /* skip trailing '.' */

            ++from;

            --len;

        }

    } while (len > 0);

    /* now result contains result_bytes of data */

    if (to->data && to->len >= result_bytes) {

        PORT_Memcpy(to->data, result, to->len = result_bytes);

        rv = SECSuccess;

    } else {

        SECItem result_item = { siBuffer, NULL, 0 };

        result_item.data = result;

        result_item.len = result_bytes;

        rv = SECITEM_CopyItem(pool, to, &result_item);

    }

    return rv;

}