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
|
/*
base64.c - by Joe DF (joedf@ahkscript.org)
Released under the MIT License
See "base64.h", for more information.
Thank you for inspiration:
http://www.codeproject.com/Tips/813146/Fast-base-functions-for-encode-decode
*/
#include "base64.h"
//Base64 char table - used internally for encoding
unsigned char b64_chr[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
unsigned int b64_int(unsigned int ch) {
// ASCII to base64_int
// 65-90 Upper Case >> 0-25
// 97-122 Lower Case >> 26-51
// 48-57 Numbers >> 52-61
// 43 Plus (+) >> 62
// 47 Slash (/) >> 63
// 61 Equal (=) >> 64~
if (ch==43)
return 62;
if (ch==47)
return 63;
if (ch==61)
return 64;
if ((ch>47) && (ch<58))
return ch + 4;
if ((ch>64) && (ch<91))
return ch - 'A';
if ((ch>96) && (ch<123))
return (ch - 'a') + 26;
return 0;
}
unsigned int b64e_size(unsigned int in_size) {
// size equals 4*floor((1/3)*(in_size+2));
int i, j = 0;
for (i=0;i<in_size;i++) {
if (i % 3 == 0)
j += 1;
}
return (4*j);
}
unsigned int b64d_size(unsigned int in_size) {
return ((3*in_size)/4);
}
unsigned int
b64_encode(char* in, unsigned int in_len, char* out){
unsigned int i=0, j=0, k=0, s[3];
for (i=0;i<in_len;i++){
s[j++]=*(in+i);
if (j==3){
out[k+0] = b64_chr[ (s[0]&255)>>2 ];
out[k+1] = b64_chr[ ((s[0]&0x03)<<4)+((s[1]&0xF0)>>4) ];
out[k+2] = b64_chr[ ((s[1]&0x0F)<<2)+((s[2]&0xC0)>>6) ];
out[k+3] = b64_chr[ s[2]&0x3F ];
j=0; k+=4;
}
}
if (j) {
if (j==1)
s[1] = 0;
out[k+0] = b64_chr[ (s[0]&255)>>2 ];
out[k+1] = b64_chr[ ((s[0]&0x03)<<4)+((s[1]&0xF0)>>4) ];
if (j==2)
out[k+2] = b64_chr[ ((s[1]&0x0F)<<2) ];
else
out[k+2] = '=';
out[k+3] = '=';
k+=4;
}
out[k] = '\0';
return k;
}
unsigned int
b64_decode(char* in, unsigned int in_len, char* out){
unsigned int i=0, j=0, k=0, s[4];
for (i=0;i<in_len;i++) {
s[j++]=b64_int(*(in+i));
if (j==4) {
out[k+0] = ((s[0]&255)<<2)+((s[1]&0x30)>>4);
if (s[2]!=64) {
out[k+1] = ((s[1]&0x0F)<<4)+((s[2]&0x3C)>>2);
if ((s[3]!=64)) {
out[k+2] = ((s[2]&0x03)<<6)+(s[3]); k+=3;
} else {
k+=2;
}
} else {
k+=1;
}
j=0;
}
}
return k;
}
|