File Coverage

inc/matrixssl-3-9-3-open/crypto/keyformat/base64.c

Criterion	Covered	Total	%
statement	24	30	80.0
branch	20	28	71.4
condition			n/a
subroutine			n/a
pod			n/a
total	44	58	75.8

/**
 *      @file    base64.c
 *      @version 950bba4 (HEAD -> master)
 *
 *      Base64 operations.
 */
/*
 *      Copyright (c) 2013-2017 INSIDE Secure Corporation
 *      Copyright (c) PeerSec Networks, 2002-2011
 *      All Rights Reserved
 *
 *      The latest version of this code is available at http://www.matrixssl.org
 *
 *      This software is open source; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This General Public License does NOT permit incorporating this software
 *      into proprietary programs.  If you are unable to comply with the GPL, a
 *      commercial license for this software may be purchased from INSIDE at
 *      http://www.insidesecure.com/
 *
 *      This program is distributed in WITHOUT ANY WARRANTY; without even the
 *      implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *      See the GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *      http://www.gnu.org/copyleft/gpl.html
 */
/******************************************************************************/

#include "../cryptoImpl.h"

#ifdef USE_BASE64_DECODE

static const unsigned char map[] = {
    255, 255, 255, 255,  255,  255,  255, 255,  255,   255,   255,   255,
    255, 255, 255, 255,  255,  255,  255, 255,  255,   255,   255,   255,
    255, 255, 255, 255,  255,  255,  255, 255,  255,   255,   255,   255,
    255, 255, 255, 255,  255,  255,  255, 62,   255,   255,   255,   63,
    52,  53,  54,  55,   56,   57,   58,  59,   60,    61,    255,   255,
    255, 254, 255, 255,  255,  0,    1,   2,    3,     4,     5,     6,
    7,   8,   9,   10,   11,   12,   13,  14,   15,    16,    17,    18,
    19,  20,  21,  22,   23,   24,   25,  255,  255,   255,   255,   255,
    255, 26,  27,  28,   29,   30,   31,  32,   33,    34,    35,    36,
    37,  38,  39,  40,   41,   42,   43,  44,   45,    46,    47,    48,
    49,  50,  51
/*           , 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
   255, 255, 255, 255
 */
};

int32_t psBase64decode(const unsigned char *in, psSize_t len,
    unsigned char *out, psSize_t *outlen)
{
    unsigned int t;
    unsigned char c;
    uint16_t x, y, z;
    int16_t g;

    if (in == NULL || out == NULL || outlen == NULL)
    {
        psTraceCrypto("Arg failure to psBase64decode\n");
        return PS_ARG_FAIL;
    }
    g = 3;
    for (x = y = z = t = 0; x < len; x++)
    {
        /* Save a little space by skipping values that would be 255 in the full map */
        if (in[x] > 122)
        {
            continue;
        }
        c = map[in[x]];
        if (c == 255)
        {
            continue;
        }
        /* the final '=' symbols are read and used to trim the remaining bytes */
        if (c == 254)
        {
            c = 0;
            /* prevent g < 0 which would potentially allow an overflow later */
            if (--g < 0)
            {
                psTraceCrypto("Negative g failure in psBase64decode\n");
                return PS_LIMIT_FAIL;
            }
        }
        else if (g != 3)
        {
            /* we only allow = to be at the end */
            psTraceCrypto("g failure in psBase64decode\n");
            return PS_PARSE_FAIL;
        }

        t = (t << 6) | c;

        if (++y == 4)
        {
            if (z + g > *outlen)
            {
                psTraceCrypto("outlen too small for psBase64decode\n");
                return PS_LIMIT_FAIL;
            }
            out[z++] = (unsigned char) ((t >> 16) & 0xFF);
            if (g > 1)
            {
                out[z++] = (unsigned char) ((t >> 8) & 0xFF);
            }
            if (g > 2)
            {
                out[z++] = (unsigned char) (t & 0xFF);
            }
            y = t = 0;
        }
    }
    if (y != 0)
    {
        psTraceCrypto("y failure in psBase64decode\n");
        return PS_PARSE_FAIL;
    }
    *outlen = z;
    return PS_SUCCESS;
}

#endif /* USE_BASE64_DECODE */

/******************************************************************************/

/******************************************************************************/