/* Copyright (C) 2005 J.F.Dockes
* This program is free software; 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 program is distributed in the hope that it will be useful,
* but 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.
*/
#include <stdio.h>
#include <sys/types.h>
#include <cstring>
#include <string>
#ifndef NO_NAMESPACES
using std::string;
#endif /* NO_NAMESPACES */
#undef DEBUG_BASE64
#ifdef DEBUG_BASE64
#define DPRINT(X) fprintf X
#else
#define DPRINT(X)
#endif
// This is adapted from FreeBSD's code, quite modified for performance.
// Tests on a Mac pro 2.1G with a 166MB base64 file
//
// The original version used strchr to lookup the base64 value from
// the input code:
// real 0m13.053s user 0m12.574s sys 0m0.471s
// Using a direct access, 256 entries table:
// real 0m3.073s user 0m2.600s sys 0m0.439s
// Using a variable to hold the array length (instead of in.length()):
// real 0m2.972s user 0m2.527s sys 0m0.433s
// Using values from the table instead of isspace() (final)
// real 0m2.513s user 0m2.059s sys 0m0.439s
//
// The table has one entry per char value (0-256). Invalid base64
// chars take value 256, whitespace 255, Pad ('=') 254.
// Valid char points contain their base64 value (0-63)
static const int b64values[] = {
/* 0 */ 256,/* 1 */ 256,/* 2 */ 256,/* 3 */ 256,/* 4 */ 256,
/* 5 */ 256,/* 6 */ 256,/* 7 */ 256,/* 8 */ 256,
/*9 ht */ 255,/* 10 nl */ 255,/* 11 vt */ 255,/* 12 np/ff*/ 255,/* 13 cr */ 255,
/* 14 */ 256,/* 15 */ 256,/* 16 */ 256,/* 17 */ 256,/* 18 */ 256,/* 19 */ 256,
/* 20 */ 256,/* 21 */ 256,/* 22 */ 256,/* 23 */ 256,/* 24 */ 256,/* 25 */ 256,
/* 26 */ 256,/* 27 */ 256,/* 28 */ 256,/* 29 */ 256,/* 30 */ 256,/* 31 */ 256,
/* 32 sp */ 255,
/* ! */ 256,/* " */ 256,/* # */ 256,/* $ */ 256,/* % */ 256,
/* & */ 256,/* ' */ 256,/* ( */ 256,/* ) */ 256,/* * */ 256,
/* + */ 62,
/* , */ 256,/* - */ 256,/* . */ 256,
/* / */ 63,
/* 0 */ 52,/* 1 */ 53,/* 2 */ 54,/* 3 */ 55,/* 4 */ 56,/* 5 */ 57,/* 6 */ 58,
/* 7 */ 59,/* 8 */ 60,/* 9 */ 61,
/* : */ 256,/* ; */ 256,/* < */ 256,
/* = */ 254,
/* > */ 256,/* ? */ 256,/* @ */ 256,
/* A */ 0,/* B */ 1,/* C */ 2,/* D */ 3,/* E */ 4,/* F */ 5,/* G */ 6,/* H */ 7,
/* I */ 8,/* J */ 9,/* K */ 10,/* L */ 11,/* M */ 12,/* N */ 13,/* O */ 14,
/* P */ 15,/* Q */ 16,/* R */ 17,/* S */ 18,/* T */ 19,/* U */ 20,/* V */ 21,
/* W */ 22,/* X */ 23,/* Y */ 24,/* Z */ 25,
/* [ */ 256,/* \ */ 256,/* ] */ 256,/* ^ */ 256,/* _ */ 256,/* ` */ 256,
/* a */ 26,/* b */ 27,/* c */ 28,/* d */ 29,/* e */ 30,/* f */ 31,/* g */ 32,
/* h */ 33,/* i */ 34,/* j */ 35,/* k */ 36,/* l */ 37,/* m */ 38,/* n */ 39,
/* o */ 40,/* p */ 41,/* q */ 42,/* r */ 43,/* s */ 44,/* t */ 45,/* u */ 46,
/* v */ 47,/* w */ 48,/* x */ 49,/* y */ 50,/* z */ 51,
/* { */ 256,/* | */ 256,/* } */ 256,/* ~ */ 256,
256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,
256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,
256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,
256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,
256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,
256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,256,
256,256,256,256,256,256,256,256,
};
static const char Base64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char Pad64 = '=';
bool base64_decode(const string& in, string& out)
{
int io = 0, state = 0, ch = 0;
unsigned int ii = 0;
out.clear();
size_t ilen = in.length();
out.reserve(ilen);
for (ii = 0; ii < ilen; ii++) {
ch = (unsigned char)in[ii];
int value = b64values[ch];
if (value == 255) /* Skip whitespace anywhere. */
continue;
if (ch == Pad64)
break;
if (value == 256) {
/* A non-base64 character. */
DPRINT((stderr, "base64_dec: non-base64 char at pos %d\n", ii));
return false;
}
switch (state) {
case 0:
out += value << 2;
state = 1;
break;
case 1:
out[io] |= value >> 4;
out += (value & 0x0f) << 4 ;
io++;
state = 2;
break;
case 2:
out[io] |= value >> 2;
out += (value & 0x03) << 6;
io++;
state = 3;
break;
case 3:
out[io] |= value;
io++;
state = 0;
break;
default:
fprintf(stderr, "base64_dec: internal!bad state!\n");
return false;
}
}
/*
* We are done decoding Base-64 chars. Let's see if we ended
* on a byte boundary, and/or with erroneous trailing characters.
*/
if (ch == Pad64) { /* We got a pad char. */
ch = in[ii++]; /* Skip it, get next. */
switch (state) {
case 0: /* Invalid = in first position */
case 1: /* Invalid = in second position */
DPRINT((stderr, "base64_dec: pad char in state 0/1\n"));
return false;
case 2: /* Valid, means one byte of info */
/* Skip any number of spaces. */
for (; ii < in.length(); ch = in[ii++])
if (!isspace((unsigned char)ch))
break;
/* Make sure there is another trailing = sign. */
if (ch != Pad64) {
DPRINT((stderr, "base64_dec: missing pad char!\n"));
// Well, there are bad encoders out there. Let it pass
// return false;
}
ch = in[ii++]; /* Skip the = */
/* Fall through to "single trailing =" case. */
/* FALLTHROUGH */
case 3: /* Valid, means two bytes of info */
/*
* We know this char is an =. Is there anything but
* whitespace after it?
*/
for (; ii < in.length(); ch = in[ii++])
if (!isspace((unsigned char)ch)) {
DPRINT((stderr, "base64_dec: non-white at eod: 0x%x\n",
(unsigned int)((unsigned char)ch)));
// Well, there are bad encoders out there. Let it pass
//return false;
}
/*
* Now make sure for cases 2 and 3 that the "extra"
* bits that slopped past the last full byte were
* zeros. If we don't check them, they become a
* subliminal channel.
*/
if (out[io] != 0) {
DPRINT((stderr, "base64_dec: bad extra bits!\n"));
// Well, there are bad encoders out there. Let it pass
out[io] = 0;
// return false;
}
// We've appended an extra 0.
out.resize(io);
}
} else {
/*
* We ended by seeing the end of the string. Make sure we
* have no partial bytes lying around.
*/
if (state != 0) {
DPRINT((stderr, "base64_dec: bad final state\n"));
return false;
}
}
DPRINT((stderr, "base64_dec: ret ok, io %d sz %d len %d value [%s]\n",
io, (int)out.size(), (int)out.length(), out.c_str()));
return true;
}
#undef Assert
#define Assert(X)
void base64_encode(const string &in, string &out)
{
unsigned char input[3];
unsigned char output[4];
out.clear();
int srclength = in.length();
int sidx = 0;
while (2 < srclength) {
input[0] = in[sidx++];
input[1] = in[sidx++];
input[2] = in[sidx++];
srclength -= 3;
output[0] = input[0] >> 2;
output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
output[3] = input[2] & 0x3f;
Assert(output[0] < 64);
Assert(output[1] < 64);
Assert(output[2] < 64);
Assert(output[3] < 64);
out += Base64[output[0]];
out += Base64[output[1]];
out += Base64[output[2]];
out += Base64[output[3]];
}
/* Now we worry about padding. */
if (0 != srclength) {
/* Get what's left. */
input[0] = input[1] = input[2] = '\0';
for (int i = 0; i < srclength; i++)
input[i] = in[sidx++];
output[0] = input[0] >> 2;
output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
Assert(output[0] < 64);
Assert(output[1] < 64);
Assert(output[2] < 64);
out += Base64[output[0]];
out += Base64[output[1]];
if (srclength == 1)
out += Pad64;
else
out += Base64[output[2]];
out += Pad64;
}
return;
}
#ifdef TEST_BASE64
#include <stdio.h>
#include <stdlib.h>
#include "readfile.h"
const char *thisprog;
static char usage [] = "testfile\n\n"
;
static void
Usage(void)
{
fprintf(stderr, "%s: usage:\n%s", thisprog, usage);
exit(1);
}
static int op_flags;
#define OPT_MOINS 0x1
#define OPT_i 0x2
#define OPT_P 0x4
int main(int argc, char **argv)
{
thisprog = argv[0];
argc--; argv++;
while (argc > 0 && **argv == '-') {
(*argv)++;
if (!(**argv))
/* Cas du "adb - core" */
Usage();
while (**argv)
switch (*(*argv)++) {
case 'i': op_flags |= OPT_i; break;
default: Usage(); break;
}
argc--; argv++;
}
if (op_flags & OPT_i) {
const char *values[] = {"", "1", "12", "123", "1234",
"12345", "123456"};
int nvalues = sizeof(values) / sizeof(char *);
string in, out, back;
int err = 0;
for (int i = 0; i < nvalues; i++) {
in = values[i];
base64_encode(in, out);
base64_decode(out, back);
if (in != back) {
fprintf(stderr, "In [%s] %d != back [%s] %d (out [%s] %d\n",
in.c_str(), int(in.length()),
back.c_str(), int(back.length()),
out.c_str(), int(out.length())
);
err++;
}
}
in.erase();
in += char(0);
in += char(0);
in += char(0);
in += char(0);
base64_encode(in, out);
base64_decode(out, back);
if (in != back) {
fprintf(stderr, "In [%s] %d != back [%s] %d (out [%s] %d\n",
in.c_str(), int(in.length()),
back.c_str(), int(back.length()),
out.c_str(), int(out.length())
);
err++;
}
exit(!(err == 0));
} else {
if (argc > 1)
Usage();
string infile;
if (argc == 1)
infile = *argv++;argc--;
string idata, reason;
if (!file_to_string(infile, idata, &reason)) {
fprintf(stderr, "Can't read file: %s\n", reason.c_str());
exit(1);
}
string odata;
if (!base64_decode(idata, odata)) {
fprintf(stderr, "Decoding failed\n");
exit(1);
}
write(1, odata.c_str(),
odata.size() * sizeof(string::value_type));
exit(0);
}
}
#endif