/[dynamips]/upstream/dynamips-0.2.5/base64.c
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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Contents of /upstream/dynamips-0.2.5/base64.c

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Revision 1 - (show annotations)
Sat Oct 6 16:01:44 2007 UTC (12 years, 1 month ago) by dpavlin
File MIME type: text/plain
File size: 3311 byte(s)
import 0.2.5 from upstream

1 /*
2 * base64.c -- base-64 conversion routines.
3 * Copyright (C)2002 by Eric S. Raymond.
4 *
5 * For license terms, see the file COPYING in this directory.
6 *
7 * This base 64 encoding is defined in RFC2045 section 6.8,
8 * "Base64 Content-Transfer-Encoding", but lines must not be broken in the
9 * scheme used here.
10 */
11
12 #include <ctype.h>
13
14 static const char base64digits[] =
15 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
16
17 #define BAD -1
18
19 static const char base64val[] = {
20 BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD,
21 BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD,
22 BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD, 62, BAD,BAD,BAD, 63,
23 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,BAD,BAD, BAD,BAD,BAD,BAD,
24 BAD, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
25 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,BAD, BAD,BAD,BAD,BAD,
26 BAD, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
27 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,BAD, BAD,BAD,BAD,BAD
28 };
29
30 #define DECODE64(c) (isascii(c) ? base64val[c] : BAD)
31
32 /* Encode into base64 */
33 void base64_encode(unsigned char *out,const unsigned char *in,int inlen)
34 {
35 /* raw bytes in quasi-big-endian order to base 64 string (NUL-terminated) */
36 for (; inlen >= 3; inlen -= 3) {
37 *out++ = base64digits[in[0] >> 2];
38 *out++ = base64digits[((in[0] << 4) & 0x30) | (in[1] >> 4)];
39 *out++ = base64digits[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
40 *out++ = base64digits[in[2] & 0x3f];
41 in += 3;
42 }
43
44 if (inlen > 0) {
45 unsigned char fragment;
46
47 *out++ = base64digits[in[0] >> 2];
48 fragment = (in[0] << 4) & 0x30;
49 if (inlen > 1)
50 fragment |= in[1] >> 4;
51 *out++ = base64digits[fragment];
52 *out++ = (inlen < 2) ? '=' : base64digits[(in[1] << 2) & 0x3c];
53 *out++ = '=';
54 }
55 *out = '\0';
56 }
57
58 /*
59 * Decode from base64.
60 *
61 * base 64 to raw bytes in quasi-big-endian order, returning count of bytes
62 * maxlen limits output buffer size, set to zero to ignore.
63 */
64 int base64_decode(unsigned char *out,const unsigned char *in,int maxlen)
65 {
66 register unsigned char digit1, digit2, digit3, digit4;
67 int len = 0;
68
69 if (in[0] == '+' && in[1] == ' ')
70 in += 2;
71 if (*in == '\r')
72 return(0);
73
74 do {
75 digit1 = in[0];
76 if (DECODE64(digit1) == BAD)
77 return(-1);
78 digit2 = in[1];
79 if (DECODE64(digit2) == BAD)
80 return(-1);
81 digit3 = in[2];
82 if (digit3 != '=' && DECODE64(digit3) == BAD)
83 return(-1);
84 digit4 = in[3];
85 if (digit4 != '=' && DECODE64(digit4) == BAD)
86 return(-1);
87 in += 4;
88 ++len;
89
90 if (maxlen && len > maxlen)
91 return(-1);
92
93 *out++ = (DECODE64(digit1) << 2) | (DECODE64(digit2) >> 4);
94 if (digit3 != '=')
95 {
96 ++len;
97 if (maxlen && (len > maxlen))
98 return(-1);
99
100 *out++ = ((DECODE64(digit2) << 4) & 0xf0) | (DECODE64(digit3) >> 2);
101 if (digit4 != '=') {
102 ++len;
103 if (maxlen && (len > maxlen))
104 return(-1);
105 *out++ = ((DECODE64(digit3) << 6) & 0xc0) | DECODE64(digit4);
106 }
107 }
108 } while(*in && (*in != '\r') && (digit4 != '='));
109
110 return(len);
111 }

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