Disconnect hostapd from building in base
[dragonfly.git] / contrib / hostapd / src / utils / base64.c
1 /*
2  * Base64 encoding/decoding (RFC1341)
3  * Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8
9 #include "includes.h"
10
11 #include "os.h"
12 #include "base64.h"
13
14 static const unsigned char base64_table[65] =
15         "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
16
17 /**
18  * base64_encode - Base64 encode
19  * @src: Data to be encoded
20  * @len: Length of the data to be encoded
21  * @out_len: Pointer to output length variable, or %NULL if not used
22  * Returns: Allocated buffer of out_len bytes of encoded data,
23  * or %NULL on failure
24  *
25  * Caller is responsible for freeing the returned buffer. Returned buffer is
26  * nul terminated to make it easier to use as a C string. The nul terminator is
27  * not included in out_len.
28  */
29 unsigned char * base64_encode(const unsigned char *src, size_t len,
30                               size_t *out_len)
31 {
32         unsigned char *out, *pos;
33         const unsigned char *end, *in;
34         size_t olen;
35         int line_len;
36
37         olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */
38         olen += olen / 72; /* line feeds */
39         olen++; /* nul termination */
40         if (olen < len)
41                 return NULL; /* integer overflow */
42         out = os_malloc(olen);
43         if (out == NULL)
44                 return NULL;
45
46         end = src + len;
47         in = src;
48         pos = out;
49         line_len = 0;
50         while (end - in >= 3) {
51                 *pos++ = base64_table[in[0] >> 2];
52                 *pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
53                 *pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
54                 *pos++ = base64_table[in[2] & 0x3f];
55                 in += 3;
56                 line_len += 4;
57                 if (line_len >= 72) {
58                         *pos++ = '\n';
59                         line_len = 0;
60                 }
61         }
62
63         if (end - in) {
64                 *pos++ = base64_table[in[0] >> 2];
65                 if (end - in == 1) {
66                         *pos++ = base64_table[(in[0] & 0x03) << 4];
67                         *pos++ = '=';
68                 } else {
69                         *pos++ = base64_table[((in[0] & 0x03) << 4) |
70                                               (in[1] >> 4)];
71                         *pos++ = base64_table[(in[1] & 0x0f) << 2];
72                 }
73                 *pos++ = '=';
74                 line_len += 4;
75         }
76
77         if (line_len)
78                 *pos++ = '\n';
79
80         *pos = '\0';
81         if (out_len)
82                 *out_len = pos - out;
83         return out;
84 }
85
86
87 /**
88  * base64_decode - Base64 decode
89  * @src: Data to be decoded
90  * @len: Length of the data to be decoded
91  * @out_len: Pointer to output length variable
92  * Returns: Allocated buffer of out_len bytes of decoded data,
93  * or %NULL on failure
94  *
95  * Caller is responsible for freeing the returned buffer.
96  */
97 unsigned char * base64_decode(const unsigned char *src, size_t len,
98                               size_t *out_len)
99 {
100         unsigned char dtable[256], *out, *pos, block[4], tmp;
101         size_t i, count, olen;
102         int pad = 0;
103
104         os_memset(dtable, 0x80, 256);
105         for (i = 0; i < sizeof(base64_table) - 1; i++)
106                 dtable[base64_table[i]] = (unsigned char) i;
107         dtable['='] = 0;
108
109         count = 0;
110         for (i = 0; i < len; i++) {
111                 if (dtable[src[i]] != 0x80)
112                         count++;
113         }
114
115         if (count == 0 || count % 4)
116                 return NULL;
117
118         olen = count / 4 * 3;
119         pos = out = os_malloc(olen);
120         if (out == NULL)
121                 return NULL;
122
123         count = 0;
124         for (i = 0; i < len; i++) {
125                 tmp = dtable[src[i]];
126                 if (tmp == 0x80)
127                         continue;
128
129                 if (src[i] == '=')
130                         pad++;
131                 block[count] = tmp;
132                 count++;
133                 if (count == 4) {
134                         *pos++ = (block[0] << 2) | (block[1] >> 4);
135                         *pos++ = (block[1] << 4) | (block[2] >> 2);
136                         *pos++ = (block[2] << 6) | block[3];
137                         count = 0;
138                         if (pad) {
139                                 if (pad == 1)
140                                         pos--;
141                                 else if (pad == 2)
142                                         pos -= 2;
143                                 else {
144                                         /* Invalid padding */
145                                         os_free(out);
146                                         return NULL;
147                                 }
148                                 break;
149                         }
150                 }
151         }
152
153         *out_len = pos - out;
154         return out;
155 }