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/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
This library 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 Lesser General Public License for
more details.
You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
**********/
// "liveMedia"
// Copyright (c) 1996-2005 Live Networks, Inc. All rights reserved.
// Base64 encoding and decoding
// implementation
#include "Base64.hh"
#include <strDup.hh>
#include <string.h>
static char base64DecodeTable[256];
static void initBase64DecodeTable() {
int i;
for (i = 0; i < 256; ++i) base64DecodeTable[i] = (char)0x80;
// default value: invalid
for (i = 'A'; i <= 'Z'; ++i) base64DecodeTable[i] = 0 + (i - 'A');
for (i = 'a'; i <= 'z'; ++i) base64DecodeTable[i] = 26 + (i - 'a');
for (i = '0'; i <= '9'; ++i) base64DecodeTable[i] = 52 + (i - '0');
base64DecodeTable[(unsigned char)'+'] = 62;
base64DecodeTable[(unsigned char)'/'] = 63;
base64DecodeTable[(unsigned char)'='] = 0;
}
unsigned char* base64Decode(char* in, unsigned& resultSize,
Boolean trimTrailingZeros) {
static Boolean haveInitedBase64DecodeTable = False;
if (!haveInitedBase64DecodeTable) {
initBase64DecodeTable();
haveInitedBase64DecodeTable = True;
}
unsigned char* out = (unsigned char*)strDupSize(in); // ensures we have enough space
int k = 0;
int const jMax = strlen(in) - 3;
// in case "in" is not a multiple of 4 bytes (although it should be)
for (int j = 0; j < jMax; j += 4) {
char inTmp[4], outTmp[4];
for (int i = 0; i < 4; ++i) {
inTmp[i] = in[i+j];
outTmp[i] = base64DecodeTable[(unsigned char)inTmp[i]];
if ((outTmp[i]&0x80) != 0) outTmp[i] = 0; // pretend the input was 'A'
}
out[k++] = (outTmp[0]<<2) | (outTmp[1]>>4);
out[k++] = (outTmp[1]<<4) | (outTmp[2]>>2);
out[k++] = (outTmp[2]<<6) | outTmp[3];
}
if (trimTrailingZeros) {
while (k > 0 && out[k-1] == '\0') --k;
}
resultSize = k;
unsigned char* result = new unsigned char[resultSize];
memmove(result, out, resultSize);
delete[] out;
return result;
}
static const char base64Char[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
char* base64Encode(char const* orig) {
if (orig == NULL) return NULL;
unsigned const origLength = strlen(orig);
unsigned const numOrig24BitValues = origLength/3;
Boolean havePadding = origLength > numOrig24BitValues*3;
Boolean havePadding2 = origLength == numOrig24BitValues*3 + 2;
unsigned const numResultBytes = 4*(numOrig24BitValues + havePadding);
char* result = new char[numResultBytes+1]; // allow for trailing '\0'
// Map each full group of 3 input bytes into 4 output base-64 characters:
unsigned i;
for (i = 0; i < numOrig24BitValues; ++i) {
result[4*i+0] = base64Char[(orig[3*i]>>2)&0x3F];
result[4*i+1] = base64Char[(((orig[3*i]&0x3)<<4) | (orig[3*i+1]>>4))&0x3F];
result[4*i+2] = base64Char[((orig[3*i+1]<<2) | (orig[3*i+2]>>6))&0x3F];
result[4*i+3] = base64Char[orig[3*i+2]&0x3F];
}
// Now, take padding into account. (Note: i == numOrig24BitValues)
if (havePadding) {
result[4*i+0] = base64Char[(orig[3*i]>>2)&0x3F];
result[4*i+1] = base64Char[(((orig[3*i]&0x3)<<4) | (orig[3*i+1]>>4))&0x3F];
if (havePadding2) {
result[4*i+2] = base64Char[(orig[3*i+1]<<2)&0x3F];
} else {
result[4*i+2] = '=';
}
result[4*i+3] = '=';
}
result[numResultBytes] = '\0';
return result;
}
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