|
15
|
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
|
|
2 * |
|
|
3 * LibTomCrypt is a library that provides various cryptographic |
|
|
4 * algorithms in a highly modular and flexible manner. |
|
|
5 * |
|
|
6 * The library is free for all purposes without any express |
|
|
7 * guarantee it works. |
|
|
8 * |
|
|
9 * Tom St Denis, [email protected], http://libtomcrypt.org |
|
|
10 */ |
|
|
11 /* compliant base64 code donated by Wayne Scott ([email protected]) */ |
|
|
12 #include "mycrypt.h" |
|
|
13 |
|
|
14 #ifdef BASE64 |
|
|
15 |
|
|
16 static const char *codes = |
|
|
17 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
|
|
18 |
|
|
19 int base64_encode(const unsigned char *in, unsigned long len, |
|
|
20 unsigned char *out, unsigned long *outlen) |
|
|
21 { |
|
|
22 unsigned long i, len2, leven; |
|
|
23 unsigned char *p; |
|
|
24 |
|
|
25 _ARGCHK(in != NULL); |
|
|
26 _ARGCHK(out != NULL); |
|
|
27 _ARGCHK(outlen != NULL); |
|
|
28 |
|
|
29 /* valid output size ? */ |
|
|
30 len2 = 4 * ((len + 2) / 3); |
|
|
31 if (*outlen < len2 + 1) { |
|
|
32 return CRYPT_BUFFER_OVERFLOW; |
|
|
33 } |
|
|
34 p = out; |
|
|
35 leven = 3*(len / 3); |
|
|
36 for (i = 0; i < leven; i += 3) { |
|
|
37 *p++ = codes[(in[0] >> 2) & 0x3F]; |
|
|
38 *p++ = codes[(((in[0] & 3) << 4) + (in[1] >> 4)) & 0x3F]; |
|
|
39 *p++ = codes[(((in[1] & 0xf) << 2) + (in[2] >> 6)) & 0x3F]; |
|
|
40 *p++ = codes[in[2] & 0x3F]; |
|
|
41 in += 3; |
|
|
42 } |
|
|
43 /* Pad it if necessary... */ |
|
|
44 if (i < len) { |
|
|
45 unsigned a = in[0]; |
|
|
46 unsigned b = (i+1 < len) ? in[1] : 0; |
|
|
47 |
|
|
48 *p++ = codes[(a >> 2) & 0x3F]; |
|
|
49 *p++ = codes[(((a & 3) << 4) + (b >> 4)) & 0x3F]; |
|
|
50 *p++ = (i+1 < len) ? codes[(((b & 0xf) << 2)) & 0x3F] : '='; |
|
|
51 *p++ = '='; |
|
|
52 } |
|
|
53 |
|
|
54 /* append a NULL byte */ |
|
|
55 *p = '\0'; |
|
|
56 |
|
|
57 /* return ok */ |
|
|
58 *outlen = p - out; |
|
|
59 return CRYPT_OK; |
|
|
60 } |
|
|
61 |
|
|
62 #endif |
|
|
63 |
