LibreOffice Module comphelper (master)  1
base64.cxx
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1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /*
3  * This file is part of the LibreOffice project.
4  *
5  * This Source Code Form is subject to the terms of the Mozilla Public
6  * License, v. 2.0. If a copy of the MPL was not distributed with this
7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8  *
9  * This file incorporates work covered by the following license notice:
10  *
11  * Licensed to the Apache Software Foundation (ASF) under one or more
12  * contributor license agreements. See the NOTICE file distributed
13  * with this work for additional information regarding copyright
14  * ownership. The ASF licenses this file to you under the Apache
15  * License, Version 2.0 (the "License"); you may not use this file
16  * except in compliance with the License. You may obtain a copy of
17  * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18  */
19 
20 #include <comphelper/base64.hxx>
21 
22 #include <com/sun/star/uno/Sequence.hxx>
23 
24 #include <osl/diagnose.h>
25 
26 using namespace com::sun::star;
27 
28 namespace comphelper {
29 
30 const
32  { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
33  'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
34  'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
35  'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
36  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' };
37 
38 const
40  { 62,255,255,255, 63, // 43-47
41 // + /
42 
43  52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255, 0,255,255, // 48-63
44 // 0 1 2 3 4 5 6 7 8 9 =
45 
46  255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 64-79
47 // A B C D E F G H I J K L M N O
48 
49  15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255, // 80-95
50 // P Q R S T U V W X Y Z
51 
52  0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 96-111
53 // a b c d e f g h i j k l m n o
54 
55  41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 }; // 112-123
56 // p q r s t u v w x y z
57 
58 
59 static void ThreeByteToFourByte(const sal_Int8* pBuffer, const sal_Int32 nStart, const sal_Int32 nFullLen, sal_Char* aCharBuffer)
60 {
61  sal_Int32 nLen(nFullLen - nStart);
62  if (nLen > 3)
63  nLen = 3;
64  if (nLen == 0)
65  {
66  return;
67  }
68 
69  sal_Int32 nBinaer;
70  switch (nLen)
71  {
72  case 1:
73  {
74  nBinaer = static_cast<sal_uInt8>(pBuffer[nStart + 0]) << 16;
75  }
76  break;
77  case 2:
78  {
79  nBinaer = (static_cast<sal_uInt8>(pBuffer[nStart + 0]) << 16) +
80  (static_cast<sal_uInt8>(pBuffer[nStart + 1]) << 8);
81  }
82  break;
83  default:
84  {
85  nBinaer = (static_cast<sal_uInt8>(pBuffer[nStart + 0]) << 16) +
86  (static_cast<sal_uInt8>(pBuffer[nStart + 1]) << 8) +
87  static_cast<sal_uInt8>(pBuffer[nStart + 2]);
88  }
89  break;
90  }
91 
92  aCharBuffer[0] = aCharBuffer[1] = aCharBuffer[2] = aCharBuffer[3] = '=';
93 
94  sal_uInt8 nIndex (static_cast<sal_uInt8>((nBinaer & 0xFC0000) >> 18));
95  aCharBuffer[0] = aBase64EncodeTable [nIndex];
96 
97  nIndex = static_cast<sal_uInt8>((nBinaer & 0x3F000) >> 12);
98  aCharBuffer[1] = aBase64EncodeTable [nIndex];
99  if (nLen > 1)
100  {
101  nIndex = static_cast<sal_uInt8>((nBinaer & 0xFC0) >> 6);
102  aCharBuffer[2] = aBase64EncodeTable [nIndex];
103  if (nLen > 2)
104  {
105  nIndex = static_cast<sal_uInt8>((nBinaer & 0x3F));
106  aCharBuffer[3] = aBase64EncodeTable [nIndex];
107  }
108  }
109 }
110 
111 void Base64::encode(OStringBuffer& aStrBuffer, const uno::Sequence<sal_Int8>& aPass)
112 {
113  sal_Int32 i(0);
114  sal_Int32 nBufferLength(aPass.getLength());
115  const sal_Int8* pBuffer = aPass.getConstArray();
116  while (i < nBufferLength)
117  {
118  sal_Char aCharBuffer[4];
119  ThreeByteToFourByte(pBuffer, i, nBufferLength, aCharBuffer);
120  aStrBuffer.append(aCharBuffer, SAL_N_ELEMENTS(aCharBuffer));
121  i += 3;
122  }
123 }
124 
125 void Base64::encode(OUStringBuffer& aStrBuffer, const uno::Sequence<sal_Int8>& aPass)
126 {
127  sal_Int32 i(0);
128  sal_Int32 nBufferLength(aPass.getLength());
129  const sal_Int8* pBuffer = aPass.getConstArray();
130  while (i < nBufferLength)
131  {
132  sal_Char aCharBuffer[4];
133  ThreeByteToFourByte(pBuffer, i, nBufferLength, aCharBuffer);
134  aStrBuffer.appendAscii(aCharBuffer, SAL_N_ELEMENTS(aCharBuffer));
135  i += 3;
136  }
137 }
138 
139 void Base64::decode(uno::Sequence<sal_Int8>& aBuffer, const OUString& sBuffer)
140 {
141  sal_Int32 nCharsDecoded = decodeSomeChars( aBuffer, sBuffer );
142  OSL_ENSURE( nCharsDecoded == sBuffer.getLength(), "some bytes left in base64 decoding!" );
143 }
144 
145 sal_Int32 Base64::decodeSomeChars(uno::Sequence<sal_Int8>& rOutBuffer, const OUString& rInBuffer)
146 {
147  sal_Int32 nInBufferLen = rInBuffer.getLength();
148  sal_Int32 nMinOutBufferLen = (nInBufferLen / 4) * 3;
149  if( rOutBuffer.getLength() < nMinOutBufferLen )
150  rOutBuffer.realloc( nMinOutBufferLen );
151 
152  const sal_Unicode *pInBuffer = rInBuffer.getStr();
153  sal_Int8 *pOutBuffer = rOutBuffer.getArray();
154  sal_Int8 *pOutBufferStart = pOutBuffer;
155  sal_Int32 nCharsDecoded = 0;
156 
157  sal_uInt8 aDecodeBuffer[4];
158  sal_Int32 nBytesToDecode = 0;
159  sal_Int32 nBytesGotFromDecoding = 3;
160  sal_Int32 nInBufferPos= 0;
161  while( nInBufferPos < nInBufferLen )
162  {
163  sal_Unicode cChar = *pInBuffer;
164  if( cChar >= '+' && cChar <= 'z' )
165  {
166  sal_uInt8 nByte = aBase64DecodeTable[cChar-'+'];
167  if( nByte != 255 )
168  {
169  // We have found a valid character!
170  aDecodeBuffer[nBytesToDecode++] = nByte;
171 
172  // One '=' character at the end means 2 out bytes
173  // Two '=' characters at the end mean 1 out bytes
174  if( '=' == cChar && nBytesToDecode > 2 )
175  nBytesGotFromDecoding--;
176  if( 4 == nBytesToDecode )
177  {
178  // Four characters found, so we may convert now!
179  sal_uInt32 nOut = (aDecodeBuffer[0] << 18) +
180  (aDecodeBuffer[1] << 12) +
181  (aDecodeBuffer[2] << 6) +
182  aDecodeBuffer[3];
183 
184  *pOutBuffer++ = static_cast<sal_Int8>((nOut & 0xff0000) >> 16);
185  if( nBytesGotFromDecoding > 1 )
186  *pOutBuffer++ = static_cast<sal_Int8>((nOut & 0xff00) >> 8);
187  if( nBytesGotFromDecoding > 2 )
188  *pOutBuffer++ = static_cast<sal_Int8>(nOut & 0xff);
189  nCharsDecoded = nInBufferPos + 1;
190  nBytesToDecode = 0;
191  nBytesGotFromDecoding = 3;
192  }
193  }
194  else
195  {
196  nCharsDecoded++;
197  }
198  }
199  else
200  {
201  nCharsDecoded++;
202  }
203 
204  nInBufferPos++;
205  pInBuffer++;
206  }
207  if( (pOutBuffer - pOutBufferStart) != rOutBuffer.getLength() )
208  rOutBuffer.realloc( pOutBuffer - pOutBufferStart );
209 
210  return nCharsDecoded;
211 }
212 
213 }
214 
215 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
const sal_Char aBase64EncodeTable[]
signed char sal_Int8
static void ThreeByteToFourByte(const sal_Int8 *pBuffer, const sal_Int32 nStart, const sal_Int32 nFullLen, sal_Char *aCharBuffer)
Definition: base64.cxx:59
sal_uInt16 sal_Unicode
char sal_Char
#define SAL_N_ELEMENTS(arr)
int i
unsigned char sal_uInt8
const sal_uInt8 aBase64DecodeTable[]
Definition: base64.cxx:39