Commit | Line | Data |
---|---|---|
f8beb284 MW |
1 | /* $Id: encodeB.c,v 1.3 1998/03/21 18:30:27 lindberg Exp $*/ |
2 | /* $Name: ezmlm-idx-040 $*/ | |
3 | ||
4 | #include "stralloc.h" | |
5 | #include "uint32.h" | |
6 | #include "mime.h" | |
7 | #include "strerr.h" | |
8 | #include "errtxt.h" | |
9 | ||
10 | static void die_nomem(fatal) | |
11 | char *fatal; | |
12 | { | |
13 | strerr_die2x(111,fatal,ERR_NOMEM); | |
14 | } | |
15 | ||
16 | static unsigned char base64char[] = | |
17 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
18 | ||
19 | static unsigned int pos = 0; | |
20 | static unsigned int i = 0; | |
21 | static uint32 hold32; | |
22 | static unsigned char *cpout; | |
23 | ||
24 | static void addone(ch) | |
25 | unsigned char ch; | |
26 | { | |
27 | if (!(pos++)) | |
28 | hold32 = (uint32) ch; | |
29 | else | |
30 | hold32 = (hold32 << 8) | ch; | |
31 | if (pos == 3) { | |
32 | *cpout++ = base64char[(hold32 >> 18) & 0x3f]; | |
33 | *cpout++ = base64char[(hold32 >> 12) & 0x3f]; | |
34 | *cpout++ = base64char[(hold32 >> 6) & 0x3f]; | |
35 | *cpout++ = base64char[hold32 & 0x3f]; | |
36 | if (++i == 18) { | |
37 | *cpout++ = '\n'; | |
38 | i = 0; | |
39 | } | |
40 | pos = 0; | |
41 | } | |
42 | } | |
43 | ||
44 | static void dorest() | |
45 | { | |
46 | switch (pos) { | |
47 | case 2: | |
48 | hold32 = hold32 << 2; | |
49 | *cpout++ = base64char[(hold32 >> 12) & 0x3f]; | |
50 | *cpout++ = base64char[(hold32 >> 06) & 0x3f]; | |
51 | *cpout++ = base64char[hold32 & 0x3f]; | |
52 | *cpout++ = '='; | |
53 | break; | |
54 | case 1: | |
55 | hold32 = hold32 << 4; | |
56 | *cpout++ = base64char[(hold32 >> 06) & 0x3f]; | |
57 | *cpout++ = base64char[hold32 & 0x3f]; | |
58 | *cpout++ = '='; | |
59 | *cpout++ = '='; | |
60 | break; | |
61 | default: | |
62 | break; | |
63 | } | |
64 | *cpout++ = '\n'; | |
65 | } | |
66 | ||
67 | void encodeB(indata,n,outdata,control,fatal) | |
68 | unsigned char *indata; | |
69 | unsigned int n; | |
70 | stralloc *outdata; | |
71 | int control; /* 1 = init, 2 = flush */ | |
72 | char *fatal; | |
73 | /* converts any character with the high order bit set to */ | |
74 | /* base64. In: n chars of indata, out: stralloc outdata */ | |
75 | /* as '=' is not allowed within the block, we cannot flush after */ | |
76 | /* each line, so we carry over data from call to call. The last */ | |
77 | /* call to encodeB should have control = 2 to do the flushing. */ | |
78 | /* control = 0 resets, and the routine starts out reset. */ | |
79 | { | |
80 | register unsigned char ch; | |
81 | ||
82 | if (control == 1) { | |
83 | pos = 0; | |
84 | i = 0; | |
85 | } | |
86 | if (!stralloc_copys(outdata,"")) die_nomem(fatal); | |
87 | if (!stralloc_ready(outdata,n*8/3 + n/72 + 5)) die_nomem(fatal); | |
88 | cpout = (unsigned char *) outdata->s; | |
89 | while (n--) { | |
90 | ch = *indata++; | |
91 | if (ch == '\n') | |
92 | addone('\r'); | |
93 | addone(ch); | |
94 | } | |
95 | if (control == 2) | |
96 | dorest(); | |
97 | outdata->len = (unsigned int) (cpout - (unsigned char *) outdata->s); | |
98 | } | |
99 |