389-ds-base/lib/ldaputil/encode.c

/** BEGIN COPYRIGHT BLOCK
 * Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
 * Copyright (C) 2021 Red Hat, Inc.
 * All rights reserved.
 *
 * License: GPL (version 3 or any later version).
 * See LICENSE for details.
 * END COPYRIGHT BLOCK **/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif


/* This was malloc.h - but it's moved to stdlib.h on most platforms, and FBSD is strict */
/* Make it stdlib.h, and revert to malloc.h with ifdefs if we have issues here. WB 2016 */
#include <stdlib.h>
#include <string.h>
#include <ldaputil/certmap.h>
#include <ldaputil/encode.h>

/* The magic set of 64 chars in the uuencoded data */
static unsigned char uuset[] = {
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
    'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
    'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
    '8', '9', '+', '/'};

static int
do_uuencode(unsigned char *src, unsigned char *dst, int srclen)
{
    int i, r;
    unsigned char *p;

    /* To uuencode, we snip 8 bits from 3 bytes and store them as
6 bits in 4 bytes.   6*4 == 8*3 (get it?) and 6 bits per byte
yields nice clean bytes

It goes like this:
        AAAAAAAA BBBBBBBB CCCCCCCC
turns into the standard set of uuencode ascii chars indexed by numbers:
        00AAAAAA 00AABBBB 00BBBBCC 00CCCCCC

Snip-n-shift, snip-n-shift, etc....

*/

    for (p = dst, i = 0; i < srclen; i += 3) {
        /* Do 3 bytes of src */
        char b0, b1, b2;

        b0 = src[0];
        if (i == srclen - 1)
            b1 = b2 = '\0';
        else if (i == srclen - 2) {
            b1 = src[1];
            b2 = '\0';
        } else {
            b1 = src[1];
            b2 = src[2];
        }

        *p++ = uuset[b0 >> 2];
        *p++ = uuset[(((b0 & 0x03) << 4) | ((b1 & 0xf0) >> 4))];
        *p++ = uuset[(((b1 & 0x0f) << 2) | ((b2 & 0xc0) >> 6))];
        *p++ = uuset[b2 & 0x3f];
        src += 3;
    }
    *p = 0;                                        /* terminate the string */
    r = (unsigned char *)p - (unsigned char *)dst; /* remember how many we did */

    /* Always do 4-for-3, but if not round threesome, have to go
          clean up the last extra bytes */
    
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wanalyzer-out-of-bounds"
    for (; i != srclen; i--)
        *--p = '=';
#pragma GCC diagnostic pop

    return r;
}

const unsigned char pr2six[256] = {
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64, 64, 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, 64, 64, 64, 64, 64, 64, 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,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64};

static char *
_uudecode(const char *bufcoded)
{
    const char *bufin = bufcoded;
    unsigned char *bufout;
    int nprbytes;
    unsigned char *bufplain;
    int nbytesdecoded;

    /* Find the length */
    while (pr2six[(int)*(bufin++)] <= 63)
        ;
    nprbytes = bufin - bufcoded - 1;
    nbytesdecoded = ((nprbytes + 3) / 4) * 3;

    bufout = (unsigned char *)malloc(nbytesdecoded + 1);
    if (bufout == NULL) {
        return NULL;
    }            
    bufplain = bufout;

    bufin = bufcoded;

    while (nprbytes > 0) {
        *(bufout++) = (unsigned char)(pr2six[(int)(*bufin)] << 2 | pr2six[(int)bufin[1]] >> 4);
        *(bufout++) = (unsigned char)(pr2six[(int)bufin[1]] << 4 | pr2six[(int)bufin[2]] >> 2);
        *(bufout++) = (unsigned char)(pr2six[(int)bufin[2]] << 6 | pr2six[(int)bufin[3]]);
        bufin += 4;
        nprbytes -= 4;
    }

    if (nprbytes & 03) {
        if (pr2six[(int)bufin[-2]] > 63)
            nbytesdecoded -= 2;
        else
            nbytesdecoded -= 1;
    }
    bufplain[nbytesdecoded] = '\0';

    return (char *)bufplain;
}


char *
dbconf_encodeval(const char *val)
{
    int len = strlen(val);
    char *dst = (char *)malloc(2 * len);

    if (dst) {
        do_uuencode((unsigned char *)val, (unsigned char *)dst, len);
    }

    return dst;
}

char *
dbconf_decodeval(const char *val)
{
    return _uudecode(val);
}