File: ConvertBase64.cpp

package info (click to toggle)
openscenegraph-3.4 3.4.1+dfsg1-5
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 36,912 kB
  • sloc: cpp: 392,492; ansic: 23,625; java: 1,020; yacc: 548; makefile: 449; objc: 288; xml: 155; lex: 151
file content (327 lines) | stat: -rw-r--r-- 10,788 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * 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
 * OpenSceneGraph Public License for more details.
*/

/* This file is derived from the libb64 project which itself was released to public domain.
 * For details, see http://sourceforge.net/projects/libb64. Original code by Chris Venter
 * c++ wrapper for a base64 encoding and decoding algorithm
*/

#include <osgDB/ConvertBase64>

#include <sstream>
#include <string.h>

namespace osgDB
{

    const int CHARS_PER_LINE = 72;

    int base64_decode_value(char value_in)
    {
        static const signed char decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51};
        static const char decoding_size = sizeof(decoding);
        value_in -= 43;
        if (value_in < 0 || value_in > decoding_size) return -1;
        return decoding[(int)value_in];
    }

    void base64_init_decodestate(base64_decodestate* state_in)
    {
        state_in->step = step_a;
        state_in->plainchar = 0;
    }

    int base64_decode_block(const char* code_in, const int length_in, char* plaintext_out, base64_decodestate* state_in)
    {
        const char* codechar = code_in;
        char* plainchar = plaintext_out;
        char fragment;

        *plainchar = state_in->plainchar;

        switch (state_in->step)
        {
            while (1)
            {
        case step_a:
                do {
                    if (codechar == code_in+length_in)
                    {
                        state_in->step = step_a;
                        state_in->plainchar = *plainchar;
                        return plainchar - plaintext_out;
                    }
                    fragment = (char)base64_decode_value(*codechar++);
                } while (fragment < 0);
                *plainchar    = (fragment & 0x03f) << 2;
        case step_b:
                do {
                    if (codechar == code_in+length_in)
                    {
                        state_in->step = step_b;
                        state_in->plainchar = *plainchar;
                        return plainchar - plaintext_out;
                    }
                    fragment = (char)base64_decode_value(*codechar++);
                } while (fragment < 0);
                *plainchar++ |= (fragment & 0x030) >> 4;
                *plainchar    = (fragment & 0x00f) << 4;
        case step_c:
                do {
                    if (codechar == code_in+length_in)
                    {
                        state_in->step = step_c;
                        state_in->plainchar = *plainchar;
                        return plainchar - plaintext_out;
                    }
                    fragment = (char)base64_decode_value(*codechar++);
                } while (fragment < 0);
                *plainchar++ |= (fragment & 0x03c) >> 2;
                *plainchar    = (fragment & 0x003) << 6;
        case step_d:
                do {
                    if (codechar == code_in+length_in)
                    {
                        state_in->step = step_d;
                        state_in->plainchar = *plainchar;
                        return plainchar - plaintext_out;
                    }
                    fragment = (char)base64_decode_value(*codechar++);
                } while (fragment < 0);
                *plainchar++   |= (fragment & 0x03f);
            }
        }
        /* control should not reach here */
        return plainchar - plaintext_out;
    }

    void base64_init_encodestate(base64_encodestate* state_in)
    {
        state_in->step = step_A;
        state_in->result = 0;
        state_in->stepcount = 0;
    }

    char base64_encode_value(char value_in)
    {
        static const char* encoding = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        if (value_in > 63) return '=';
        return encoding[(int)value_in];
    }

    int base64_encode_block(const char* plaintext_in, int length_in, char* code_out, base64_encodestate* state_in)
    {
        const char* plainchar = plaintext_in;
        const char* const plaintextend = plaintext_in + length_in;
        char* codechar = code_out;
        char result;
        char fragment;

        result = state_in->result;

        switch (state_in->step)
        {
            while (1)
            {
        case step_A:
                if (plainchar == plaintextend)
                {
                    state_in->result = result;
                    state_in->step = step_A;
                    return codechar - code_out;
                }
                fragment = *plainchar++;
                result = (fragment & 0x0fc) >> 2;
                *codechar++ = base64_encode_value(result);
                result = (fragment & 0x003) << 4;
        case step_B:
                if (plainchar == plaintextend)
                {
                    state_in->result = result;
                    state_in->step = step_B;
                    return codechar - code_out;
                }
                fragment = *plainchar++;
                result |= (fragment & 0x0f0) >> 4;
                *codechar++ = base64_encode_value(result);
                result = (fragment & 0x00f) << 2;
        case step_C:
                if (plainchar == plaintextend)
                {
                    state_in->result = result;
                    state_in->step = step_C;
                    return codechar - code_out;
                }
                fragment = *plainchar++;
                result |= (fragment & 0x0c0) >> 6;
                *codechar++ = base64_encode_value(result);
                result  = (fragment & 0x03f) >> 0;
                *codechar++ = base64_encode_value(result);

                ++(state_in->stepcount);
                if (state_in->stepcount == CHARS_PER_LINE/4)
                {
                    *codechar++ = '\n';
                    state_in->stepcount = 0;
                }
            }
        }
        /* control should not reach here */
        return codechar - code_out;
    }

    int base64_encode_blockend(char* code_out, base64_encodestate* state_in)
    {
        char* codechar = code_out;

        switch (state_in->step)
        {
        case step_B:
            *codechar++ = base64_encode_value(state_in->result);
            *codechar++ = '=';
            *codechar++ = '=';
            break;
        case step_C:
            *codechar++ = base64_encode_value(state_in->result);
            *codechar++ = '=';
            break;
        case step_A:
            break;
        }
        *codechar++ = '\n';

        return codechar - code_out;
    }

    int Base64encoder::encode(char value_in)
    {
        return base64_encode_value(value_in);
    }

    int Base64encoder::encode(const char* code_in, const int length_in, char* plaintext_out)
    {
        return base64_encode_block(code_in, length_in, plaintext_out, &_state);
    }

    int Base64encoder::encode_end(char* plaintext_out)
    {
        return base64_encode_blockend(plaintext_out, &_state);
    }

    void Base64encoder::encode(std::istream& istream_in, std::ostream& ostream_in)
    {
        base64_init_encodestate(&_state);

        const int N = _buffersize;
        char* plaintext = new char[N];
        char* code = new char[2*N];
        int plainlength;
        int codelength;

        do
        {
            istream_in.read(plaintext, N);
            plainlength = istream_in.gcount();

            codelength = encode(plaintext, plainlength, code);
            ostream_in.write(code, codelength);
        }
        while (istream_in.good() && plainlength > 0);

        codelength = encode_end(code);
        ostream_in.write(code, codelength);

        base64_init_encodestate(&_state);

        delete [] code;
        delete [] plaintext;
    }

    void Base64encoder::encode(const char* chars_in, int length_in, std::string& code_out)
    {
        std::stringstream stream_out;
        {
            std::stringstream stream_in;
            {
                stream_in<<std::string(chars_in, length_in);
            }
            stream_in.seekg(0, stream_in.beg);
            encode(stream_in, stream_out);
        }
        stream_out.seekg (0, stream_out.beg);
        code_out = stream_out.str();
    }

    int Base64decoder::decode(char value_in)
    {
        return base64_decode_value(value_in);
    }

    int Base64decoder::decode(const char* code_in, const int length_in, char* plaintext_out)
    {
        return base64_decode_block(code_in, length_in, plaintext_out, &_state);
    }

    void Base64decoder::decode(std::istream& istream_in, std::ostream& ostream_in)
    {
        base64_init_decodestate(&_state);

        const int N = _buffersize;
        char* code = new char[N];
        char* plaintext = new char[N];
        int codelength;
        int plainlength;

        do
        {
            istream_in.read((char*)code, N);
            codelength = istream_in.gcount();
            plainlength = decode(code, codelength, plaintext);
            ostream_in.write((const char*)plaintext, plainlength);
        }
        while (istream_in.good() && codelength > 0);

        base64_init_decodestate(&_state);

        delete [] code;
        delete [] plaintext;
    }

    char* Base64decoder::decode(const std::vector<std::string>& str_in, std::vector<unsigned int>& pos_out)
    {
        std::stringstream stream_out;
        {
            std::stringstream stream_in;

            pos_out.resize(str_in.size());

            for (unsigned int i = 0; i < str_in.size(); ++i)
            {
                stream_in.clear();
                stream_in<<str_in.at(i);
                stream_in.seekg(0, stream_in.beg);

                decode(stream_in, stream_out);
                pos_out.at(i) = stream_out.tellp();
            }
        }

        // Allocate memory for use with osg::Image
        const std::string str = stream_out.str();
        char* allocated_out = new char[str.size()];
        memcpy(allocated_out, str.c_str(), str.size());

        return allocated_out;
    }

} // namespace osgDB