1
2 /*
3 * Copyright (C) 2015-2018 Alibaba Group Holding Limited
4 */
5
6
7 #include <stdint.h>
8 #include <stdlib.h>
9 #include "linkkit/infra/infra_types.h"
10 #include "linkkit/infra/infra_defs.h"
11 #include "alcs_base64.h"
12
13 static int8_t g_encodingTable[] = {
14 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
15 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
16 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
17 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
18 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
19 };
20
21 static int8_t g_decodingTable[256];
22 static int32_t g_modTable[] = { 0, 2, 1 };
23
build_decoding_table()24 static void build_decoding_table()
25 {
26 static int32_t signal = 0;
27 int32_t i = 0;
28
29 if (signal != 0) {
30 return;
31 }
32
33 for (i = 0; i < 64; i++) {
34 g_decodingTable[(uint8_t)g_encodingTable[i]] = i;
35 }
36
37 signal = 1;
38 return;
39 }
40
utils_base64encode(const uint8_t * data,uint32_t inputLength,uint32_t outputLenMax,uint8_t * encodedData,uint32_t * outputLength)41 int utils_base64encode(const uint8_t *data, uint32_t inputLength,
42 uint32_t outputLenMax, uint8_t *encodedData,
43 uint32_t *outputLength)
44 {
45 uint32_t i = 0;
46 uint32_t j = 0;
47
48 if (NULL == encodedData) {
49 return FAIL_RETURN;
50 }
51
52 *outputLength = 4 * ((inputLength + 2) / 3);
53
54 if (outputLenMax < *outputLength) {
55 return FAIL_RETURN;
56 }
57
58 for (i = 0, j = 0; i < inputLength;) {
59 uint32_t octet_a = i < inputLength ? (uint8_t)data[i++] : 0;
60 uint32_t octet_b = i < inputLength ? (uint8_t)data[i++] : 0;
61 uint32_t octet_c = i < inputLength ? (uint8_t)data[i++] : 0;
62
63 uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
64
65 encodedData[j++] = g_encodingTable[(triple >> 3 * 6) & 0x3F];
66 encodedData[j++] = g_encodingTable[(triple >> 2 * 6) & 0x3F];
67 encodedData[j++] = g_encodingTable[(triple >> 1 * 6) & 0x3F];
68 encodedData[j++] = g_encodingTable[(triple >> 0 * 6) & 0x3F];
69 }
70
71 for (i = 0; i < g_modTable[inputLength % 3]; i++) {
72 encodedData[*outputLength - 1 - i] = '=';
73 }
74
75 return SUCCESS_RETURN;
76 }
77
utils_base64decode(const uint8_t * data,uint32_t inputLength,uint32_t outputLenMax,uint8_t * decodedData,uint32_t * outputLength)78 int utils_base64decode(const uint8_t *data, uint32_t inputLength,
79 uint32_t outputLenMax, uint8_t *decodedData,
80 uint32_t *outputLength)
81 {
82 uint32_t i = 0;
83 uint32_t j = 0;
84 uint32_t sextet_a = 0;
85 uint32_t sextet_b = 0;
86 uint32_t sextet_c = 0;
87 uint32_t sextet_d = 0;
88 uint32_t triple = 0;
89
90 build_decoding_table();
91
92 if (inputLength % 4 != 0) {
93 return FAIL_RETURN;
94 }
95
96 *outputLength = inputLength / 4 * 3;
97
98 if (data[inputLength - 1] == '=') {
99 (*outputLength)--;
100 }
101
102 if (data[inputLength - 2] == '=') {
103 (*outputLength)--;
104 }
105
106 if (outputLenMax < *outputLength) {
107 return FAIL_RETURN;
108 }
109
110 for (i = 0, j = 0; i < inputLength;) {
111 sextet_a = data[i] == '=' ? 0 & i++ : g_decodingTable[data[i++]];
112 sextet_b = data[i] == '=' ? 0 & i++ : g_decodingTable[data[i++]];
113 sextet_c = data[i] == '=' ? 0 & i++ : g_decodingTable[data[i++]];
114 sextet_d = data[i] == '=' ? 0 & i++ : g_decodingTable[data[i++]];
115
116 triple = (sextet_a << 3 * 6) + (sextet_b << 2 * 6) +
117 (sextet_c << 1 * 6) + (sextet_d << 0 * 6);
118
119 if (j < *outputLength) {
120 decodedData[j++] = (triple >> 2 * 8) & 0xFF;
121 }
122
123 if (j < *outputLength) {
124 decodedData[j++] = (triple >> 1 * 8) & 0xFF;
125 }
126
127 if (j < *outputLength) {
128 decodedData[j++] = (triple >> 0 * 8) & 0xFF;
129 }
130 }
131
132 return SUCCESS_RETURN;
133 }
134
135