1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_LIBDEXFILE_DEX_BASE64_TEST_UTIL_H_
18 #define ART_LIBDEXFILE_DEX_BASE64_TEST_UTIL_H_
19 
20 #include <stdint.h>
21 #include <stdlib.h>
22 
23 #include <memory>
24 #include <vector>
25 
26 #include <android-base/logging.h>
27 
28 namespace art {
29 
DecodeBase64(const char * src,size_t * dst_size)30 static inline uint8_t* DecodeBase64(const char* src, size_t* dst_size) {
31   static const uint8_t kBase64Map[256] = {
32     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
33     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
34     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
35     255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,
36     52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,
37     255, 254, 255, 255, 255,   0,   1,   2,   3,   4,   5,   6,
38       7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,
39      19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255, 255,
40     255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,
41      37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
42      49,  50,  51, 255, 255, 255, 255, 255, 255, 255, 255, 255,
43     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
44     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
45     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
46     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
47     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
48     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
49     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
50     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
51     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
52     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
53     255, 255, 255, 255
54   };
55 
56   CHECK(dst_size != nullptr);
57   std::vector<uint8_t> tmp;
58   uint32_t t = 0, y = 0;
59   int g = 3;
60   for (size_t i = 0; src[i] != '\0'; ++i) {
61     uint8_t c = kBase64Map[src[i] & 0xFF];
62     if (c == 255) continue;
63     // the final = symbols are read and used to trim the remaining bytes
64     if (c == 254) {
65       c = 0;
66       // prevent g < 0 which would potentially allow an overflow later
67       if (--g < 0) {
68         *dst_size = 0;
69         return nullptr;
70       }
71     } else if (g != 3) {
72       // we only allow = to be at the end
73       *dst_size = 0;
74       return nullptr;
75     }
76     t = (t << 6) | c;
77     if (++y == 4) {
78       tmp.push_back((t >> 16) & 255);
79       if (g > 1) {
80         tmp.push_back((t >> 8) & 255);
81       }
82       if (g > 2) {
83         tmp.push_back(t & 255);
84       }
85       y = t = 0;
86     }
87   }
88   if (y != 0) {
89     *dst_size = 0;
90     return nullptr;
91   }
92   std::unique_ptr<uint8_t[]> dst(new uint8_t[tmp.size()]);
93   *dst_size = tmp.size();
94   std::copy(tmp.begin(), tmp.end(), dst.get());
95   return dst.release();
96 }
97 
98 }  // namespace art
99 
100 #endif  // ART_LIBDEXFILE_DEX_BASE64_TEST_UTIL_H_
101