FFmpeg: libavutil/base64.c Source File

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libavutil

base64.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

6 * FFmpeg is free software; you can redistribute it and/or

7 * modify it under the terms of the GNU Lesser General Public

8 * License as published by the Free Software Foundation; either

9 * version 2.1 of the License, or (at your option) any later version.

10 *

11 * FFmpeg is distributed in the hope that it will be useful,

12 * but WITHOUT ANY WARRANTY; without even the implied warranty of

13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

14 * Lesser General Public License for more details.

15 *

16 * You should have received a copy of the GNU Lesser General Public

17 * License along with FFmpeg; if not, write to the Free Software

18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

19 */

21 /**

22 * @file

23 * @brief Base64 encode/decode

24 * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)

25 */

27 #include "common.h"

28 #include "base64.h"

29 #include "intreadwrite.h"

31 /* ---------------- private code */

32 static const uint8_t map2[256] =

33 {

34 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

35 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

36 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

37 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

38 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

39 0xff, 0xff, 0xff,

41 0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,

42 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,

43 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x01,

44 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,

45 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,

46 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,

47 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,

48 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,

49 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,

50 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33,

52 0xff, 0xff, 0xff, 0xff, 0xff,

53 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

54 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

55 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

56 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

57 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

58 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

59 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

60 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

61 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

62 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

63 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

64 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

65 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

66 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

67 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

68 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

69 };

71 #define BASE64_DEC_STEP(i) do { \

72 bits = map2[in[i]]; \

73 if (bits & 0x80) \

74 goto out ## i; \

75 v = i ? (v << 6) + bits : bits; \

76 } while(0)

78 int av_base64_decode(uint8_t *out, const char *in_str, int out_size)

79 {

80 uint8_t *dst = out;

81 uint8_t *end = out + out_size;

82 // no sign extension

83 const uint8_t *in = in_str;

84 unsigned bits = 0xff;

85 unsigned v;

87 while (end - dst > 3) {

88 BASE64_DEC_STEP(0);

89 BASE64_DEC_STEP(1);

90 BASE64_DEC_STEP(2);

91 BASE64_DEC_STEP(3);

92 // Using AV_WB32 directly confuses compiler

93 v = av_be2ne32(v << 8);

94 AV_WN32(dst, v);

95 dst += 3;

96 in += 4;

97 }

98 if (end - dst) {

99 BASE64_DEC_STEP(0);

100 BASE64_DEC_STEP(1);

101 BASE64_DEC_STEP(2);

102 BASE64_DEC_STEP(3);

103 *dst++ = v >> 16;

104 if (end - dst)

105 *dst++ = v >> 8;

106 if (end - dst)

107 *dst++ = v;

108 in += 4;

109 }

110 while (1) {

111 BASE64_DEC_STEP(0);

112 in++;

113 BASE64_DEC_STEP(0);

114 in++;

115 BASE64_DEC_STEP(0);

116 in++;

117 BASE64_DEC_STEP(0);

118 in++;

119 }

120

121 out3:

122 *dst++ = v >> 10;

123 v <<= 2;

124 out2:

125 *dst++ = v >> 4;

126 out1:

127 out0:

128 return bits & 1 ? AVERROR_INVALIDDATA : dst - out;

129 }

130

131 /*****************************************************************************

132 * b64_encode: Stolen from VLC's http.c.

133 * Simplified by Michael.

134 * Fixed edge cases and made it work from data (vs. strings) by Ryan.

135 *****************************************************************************/

136

137 char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)

138 {

139 static const char b64[] =

140 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

141 char *ret, *dst;

142 unsigned i_bits = 0;

143 int i_shift = 0;

144 int bytes_remaining = in_size;

145

146 if (in_size >= UINT_MAX / 4 ||

147 out_size < AV_BASE64_SIZE(in_size))

148 return NULL;

149 ret = dst = out;

150 while (bytes_remaining > 3) {

151 i_bits = AV_RB32(in);

152 in += 3; bytes_remaining -= 3;

153 *dst++ = b64[ i_bits>>26 ];

154 *dst++ = b64[(i_bits>>20) & 0x3F];

155 *dst++ = b64[(i_bits>>14) & 0x3F];

156 *dst++ = b64[(i_bits>>8 ) & 0x3F];

157 }

158 i_bits = 0;

159 while (bytes_remaining) {

160 i_bits = (i_bits << 8) + *in++;

161 bytes_remaining--;

162 i_shift += 8;

163 }

164 while (i_shift > 0) {

165 *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];

166 i_shift -= 6;

167 }

168 while ((dst - ret) & 3)

169 *dst++ = '=';

170 *dst = '0円';

171

172 return ret;

173 }

174

175 #ifdef TEST

176 // LCOV_EXCL_START

177

178 #define MAX_DATA_SIZE 1024

179 #define MAX_ENCODED_SIZE 2048

180

181 static int test_encode_decode(const uint8_t *data, unsigned int data_size,

182 const char *encoded_ref)

183 {

184 char encoded[MAX_ENCODED_SIZE];

185 uint8_t data2[MAX_DATA_SIZE];

186 int data2_size, max_data2_size = MAX_DATA_SIZE;

187

188 if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {

189 printf("Failed: cannot encode the input data\n");

190 return 1;

191 }

192 if (encoded_ref && strcmp(encoded, encoded_ref)) {

193 printf("Failed: encoded string differs from reference\n"

194 "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);

195 return 1;

196 }

197

198 if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) != data_size) {

199 printf("Failed: cannot decode the encoded string\n"

200 "Encoded:\n%s\n", encoded);

201 return 1;

202 }

203 if ((data2_size = av_base64_decode(data2, encoded, data_size)) != data_size) {

204 printf("Failed: cannot decode with minimal buffer\n"

205 "Encoded:\n%s\n", encoded);

206 return 1;

207 }

208 if (memcmp(data2, data, data_size)) {

209 printf("Failed: encoded/decoded data differs from original data\n");

210 return 1;

211 }

212 if (av_base64_decode(NULL, encoded, 0) != 0) {

213 printf("Failed: decode to NULL buffer\n");

214 return 1;

215 }

216 if (strlen(encoded)) {

217 char *end = strchr(encoded, '=');

218 if (!end)

219 end = encoded + strlen(encoded) - 1;

220 *end = '%';

221 if (av_base64_decode(NULL, encoded, 0) >= 0) {

222 printf("Failed: error detection\n");

223 return 1;

224 }

225 }

226

227 printf("Passed!\n");

228 return 0;

229 }

230

231 int main(int argc, char ** argv)

232 {

233 int i, error_count = 0;

234 struct test {

235 const uint8_t *data;

236 const char *encoded_ref;

237 } tests[] = {

238 { "", ""},

239 { "1", "MQ=="},

240 { "22", "MjI="},

241 { "333", "MzMz"},

242 { "4444", "NDQ0NA=="},

243 { "55555", "NTU1NTU="},

244 { "666666", "NjY2NjY2"},

245 { "abc:def", "YWJjOmRlZg=="},

246 };

247 char in[1024], out[2048];

248

249 printf("Encoding/decoding tests\n");

250 for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)

251 error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);

252

253 if (argc>1 && !strcmp(argv[1], "-t")) {

254 memset(in, 123, sizeof(in));

255 for(i=0; i<10000; i++){

256 START_TIMER

257 av_base64_encode(out, sizeof(out), in, sizeof(in));

258 STOP_TIMER("encode")

259 }

260 for(i=0; i<10000; i++){

261 START_TIMER

262 av_base64_decode(in, out, sizeof(in));

263 STOP_TIMER("decode")

264 }

265

266 for(i=0; i<10000; i++){

267 START_TIMER

268 av_base64_decode(NULL, out, 0);

269 STOP_TIMER("syntax check")

270 }

271 }

272

273 return error_count;

274 }

275

276 // LCOV_EXCL_STOP

277 #endif

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