/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 4 -*- */
/* vi: set expandtab shiftwidth=4 tabstop=4: */
/**
* \file
* <PRE>
* MODP_B64 - High performance base64 encoder/decoder
* Version 1.3 -- 17-Mar-2006
* http://modp.com/release/base64
*
* Copyright © 2005, 2006 Nick Galbreath -- nickg [at] modp [dot] com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of the modp.com nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This is the standard "new" BSD license:
* http://www.opensource.org/licenses/bsd-license.php
* </PRE>
*/
/* public header */
#include "modp_b64.h"
/*
* If you are ripping this out of the library, comment out the next
* line and uncomment the next lines as approrpiate
*/
//#include "config.h"
/* if on motoral, sun, ibm; uncomment this */
/* #define WORDS_BIGENDIAN 1 */
/* else for Intel, Amd; uncomment this */
/* #undef WORDS_BIGENDIAN */
#include "modp_b64_data.h"
#define BADCHAR 0x01FFFFFF
/**
* you can control if we use padding by commenting out this
* next line. However, I highly recommend you use padding and not
* using it should only be for compatability with a 3rd party.
* Also, 'no padding' is not tested!
*/
#define DOPAD 1
/*
* if we aren't doing padding
* set the pad character to NULL
*/
#ifndef DOPAD
#undef CHARPAD
#define CHARPAD '\0'
#endif
size_t modp_b64_encode(char* dest, const char* str, size_t len)
{
size_t i = 0;
uint8_t* p = (uint8_t*) dest;
/* unsigned here is important! */
uint8_t t1, t2, t3;
if (len > 2) {
for (; i < len - 2; i += 3) {
t1 = str[i]; t2 = str[i+1]; t3 = str[i+2];
*p++ = e0[t1];
*p++ = e1[((t1 & 0x03) << 4) | ((t2 >> 4) & 0x0F)];
*p++ = e1[((t2 & 0x0F) << 2) | ((t3 >> 6) & 0x03)];
*p++ = e2[t3];
}
}
switch (len - i) {
case 0:
break;
case 1:
t1 = str[i];
*p++ = e0[t1];
*p++ = e1[(t1 & 0x03) << 4];
*p++ = CHARPAD;
*p++ = CHARPAD;
break;
default: /* case 2 */
t1 = str[i]; t2 = str[i+1];
*p++ = e0[t1];
*p++ = e1[((t1 & 0x03) << 4) | ((t2 >> 4) & 0x0F)];
*p++ = e2[(t2 & 0x0F) << 2];
*p++ = CHARPAD;
}
*p = '\0';
return p - (uint8_t*)dest;
}
#ifdef WORDS_BIGENDIAN /* BIG ENDIAN -- SUN / IBM / MOTOROLA */
int modp_b64_decode(char* dest, const char* src, int len)
{
if (len == 0) return 0;
#ifdef DOPAD
/* if padding is used, then the message must be at least
4 chars and be a multiple of 4.
there can be at most 2 pad chars at the end */
if (len < 4 || (len % 4 != 0)) return MODP_B64_ERROR;
if (src[len-1] == CHARPAD) {
len--;
if (src[len -1] == CHARPAD) {
len--;
}
}
#endif /* DOPAD */
size_t i;
int leftover = len % 4;
size_t chunks = (leftover == 0) ? len / 4 - 1 : len /4;
uint8_t* p = (uint8_t*) dest;
uint32_t x = 0;
uint32_t* destInt = (uint32_t*) p;
uint32_t* srcInt = (uint32_t*) src;
uint32_t y = *srcInt++;
for (i = 0; i < chunks; ++i) {
x = d0[y >> 24 & 0xff] | d1[y >> 16 & 0xff] |
d2[y >> 8 & 0xff] | d3[y & 0xff];
if (x >= BADCHAR) return MODP_B64_ERROR;
*destInt = x << 8;
p += 3;
destInt = (uint32_t*)p;
y = *srcInt++;
}
switch (leftover) {
case 0:
x = d0[y >> 24 & 0xff] | d1[y >> 16 & 0xff] |
d2[y >> 8 & 0xff] | d3[y & 0xff];
if (x >= BADCHAR) return MODP_B64_ERROR;
*p++ = ((uint8_t*)&x)[1];
*p++ = ((uint8_t*)&x)[2];
*p = ((uint8_t*)&x)[3];
return (chunks+1)*3;
case 1:
x = d3[y >> 24];
*p = (uint8_t)x;
break;
case 2:
x = d3[y >> 24] *64 + d3[(y >> 16) & 0xff];
*p = (uint8_t)(x >> 4);
break;
default: /* case 3 */
x = (d3[y >> 24] *64 + d3[(y >> 16) & 0xff])*64 +
d3[(y >> 8) & 0xff];
*p++ = (uint8_t) (x >> 10);
*p = (uint8_t) (x >> 2);
break;
}
if (x >= BADCHAR) return MODP_B64_ERROR;
return 3*chunks + (6*leftover)/8;
}
#else /* LITTLE ENDIAN -- INTEL AND FRIENDS */
size_t modp_b64_decode(char* dest, const char* src, size_t len)
{
if (len == 0) return 0;
#ifdef DOPAD
/*
* if padding is used, then the message must be at least
* 4 chars and be a multiple of 4
*/
if (len < 4 || (len % 4 != 0)) return MODP_B64_ERROR; /* error */
/* there can be at most 2 pad chars at the end */
if (src[len-1] == CHARPAD) {
len--;
if (src[len -1] == CHARPAD) {
len--;
}
}
#endif
size_t i;
int leftover = len % 4;
size_t chunks = (leftover == 0) ? len / 4 - 1 : len /4;
uint8_t* p = (uint8_t*)dest;
uint32_t x = 0;
uint32_t* destInt = (uint32_t*) p;
uint32_t* srcInt = (uint32_t*) src;
uint32_t y = *srcInt++;
for (i = 0; i < chunks; ++i) {
x = d0[y & 0xff] |
d1[(y >> 8) & 0xff] |
d2[(y >> 16) & 0xff] |
d3[(y >> 24) & 0xff];
if (x >= BADCHAR) return MODP_B64_ERROR;
*destInt = x ;
p += 3;
destInt = (uint32_t*)p;
y = *srcInt++;}
switch (leftover) {
case 0:
x = d0[y & 0xff] |
d1[(y >> 8) & 0xff] |
d2[(y >> 16) & 0xff] |
d3[(y >> 24) & 0xff];
if (x >= BADCHAR) return MODP_B64_ERROR;
*p++ = ((uint8_t*)(&x))[0];
*p++ = ((uint8_t*)(&x))[1];
*p = ((uint8_t*)(&x))[2];
return (chunks+1)*3;
break;
case 1: /* with padding this is an impossible case */
x = d0[y & 0xff];
*p = *((uint8_t*)(&x)); // i.e. first char/byte in int
break;
case 2: // * case 2, 1 output byte */
x = d0[y & 0xff] | d1[y >> 8 & 0xff];
*p = *((uint8_t*)(&x)); // i.e. first char
break;
default: /* case 3, 2 output bytes */
x = d0[y & 0xff] |
d1[y >> 8 & 0xff ] |
d2[y >> 16 & 0xff]; /* 0x3c */
*p++ = ((uint8_t*)(&x))[0];
*p = ((uint8_t*)(&x))[1];
break;
}
if (x >= BADCHAR) return MODP_B64_ERROR;
return 3*chunks + (6*leftover)/8;
}
#endif /* if bigendian / else / endif */