/*
Copyright (C) 2000-2001 Dawit Alemayehu <adawit@kde.org>
Copyright (C) 2006 Alexey Proskuryakov <ap@webkit.org>
Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License (LGPL)
version 2 as published by the Free Software Foundation.
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 Library General Public
License along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
This code is based on the java implementation in HTTPClient
package by Ronald Tschalär Copyright (C) 1996-1999.
*/
#include "config.h"
#include "Base64.h"
#include <limits.h>
#include <wtf/Platform.h>
#include <wtf/StringExtras.h>
namespace WebCore {
static const char base64EncMap[64] = {
0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E,
0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33,
0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2F
};
static const char base64DecMap[128] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x3E, 0x00, 0x00, 0x00, 0x3F,
0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
0x3C, 0x3D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
0x17, 0x18, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
0x31, 0x32, 0x33, 0x00, 0x00, 0x00, 0x00, 0x00
};
void base64Encode(const Vector<char>& in, Vector<char>& out, bool insertLFs)
{
base64Encode(in.data(), in.size(), out, insertLFs);
}
void base64Encode(const char* data, unsigned len, Vector<char>& out, bool insertLFs)
{
out.clear();
if (!len)
return;
// If the input string is pathologically large, just return nothing.
// Note: Keep this in sync with the "out_len" computation below.
// Rather than being perfectly precise, this is a bit conservative.
const unsigned maxInputBufferSize = UINT_MAX / 77 * 76 / 4 * 3 - 2;
if (len > maxInputBufferSize)
return;
unsigned sidx = 0;
unsigned didx = 0;
unsigned out_len = ((len + 2) / 3) * 4;
// Deal with the 76 character per line limit specified in RFC 2045.
insertLFs = (insertLFs && out_len > 76);
if (insertLFs)
out_len += ((out_len - 1) / 76);
int count = 0;
out.grow(out_len);
// 3-byte to 4-byte conversion + 0-63 to ascii printable conversion
if (len > 1) {
while (sidx < len - 2) {
if (insertLFs) {
if (count && (count % 76) == 0)
out[didx++] = '\n';
count += 4;
}
out[didx++] = base64EncMap[(data[sidx] >> 2) & 077];
out[didx++] = base64EncMap[((data[sidx + 1] >> 4) & 017) | ((data[sidx] << 4) & 077)];
out[didx++] = base64EncMap[((data[sidx + 2] >> 6) & 003) | ((data[sidx + 1] << 2) & 077)];
out[didx++] = base64EncMap[data[sidx + 2] & 077];
sidx += 3;
}
}
if (sidx < len) {
if (insertLFs && (count > 0) && (count % 76) == 0)
out[didx++] = '\n';
out[didx++] = base64EncMap[(data[sidx] >> 2) & 077];
if (sidx < len - 1) {
out[didx++] = base64EncMap[((data[sidx + 1] >> 4) & 017) | ((data[sidx] << 4) & 077)];
out[didx++] = base64EncMap[(data[sidx + 1] << 2) & 077];
} else
out[didx++] = base64EncMap[(data[sidx] << 4) & 077];
}
// Add padding
while (didx < out.size()) {
out[didx] = '=';
didx++;
}
}
bool base64Decode(const Vector<char>& in, Vector<char>& out)
{
out.clear();
// If the input string is pathologically large, just return nothing.
if (in.size() > UINT_MAX)
return false;
return base64Decode(in.data(), in.size(), out);
}
bool base64Decode(const char* data, unsigned len, Vector<char>& out)
{
out.clear();
if (len == 0)
return true;
while (len && data[len-1] == '=')
--len;
out.grow(len);
for (unsigned idx = 0; idx < len; idx++) {
unsigned char ch = data[idx];
if ((ch > 47 && ch < 58) || (ch > 64 && ch < 91) || (ch > 96 && ch < 123) || ch == '+' || ch == '/' || ch == '=')
out[idx] = base64DecMap[ch];
else
return false;
}
// 4-byte to 3-byte conversion
unsigned outLen = len - ((len + 3) / 4);
if (!outLen || ((outLen + 2) / 3) * 4 < len)
return false;
unsigned sidx = 0;
unsigned didx = 0;
if (outLen > 1) {
while (didx < outLen - 2) {
out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003));
out[didx + 1] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017));
out[didx + 2] = (((out[sidx + 2] << 6) & 255) | (out[sidx + 3] & 077));
sidx += 4;
didx += 3;
}
}
if (didx < outLen)
out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003));
if (++didx < outLen)
out[didx] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017));
if (outLen < out.size())
out.shrink(outLen);
return true;
}
}