base64.c
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00001 /*
00002  * Base64 encoding/decoding (RFC1341)
00003  * Copyright (c) 2005, Jouni Malinen <j@w1.fi>
00004  *
00005  * This program is free software; you can redistribute it and/or modify
00006  * it under the terms of the GNU General Public License version 2 as
00007  * published by the Free Software Foundation.
00008  *
00009  * Alternatively, this software may be distributed under the terms of BSD
00010  * license.
00011  *
00012  * See README and COPYING for more details.
00013  */
00014 
00015 #include "includes.h"
00016 
00017 #include "os.h"
00018 #include "base64.h"
00019 
00020 static const unsigned char base64_table[65] =
00021         "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
00022 
00035 unsigned char * base64_encode(const unsigned char *src, size_t len,
00036                               size_t *out_len)
00037 {
00038         unsigned char *out, *pos;
00039         const unsigned char *end, *in;
00040         size_t olen;
00041         int line_len;
00042 
00043         olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */
00044         olen += olen / 72; /* line feeds */
00045         olen++; /* nul termination */
00046         if (olen < len)
00047                 return NULL; /* integer overflow */
00048         out = os_malloc(olen);
00049         if (out == NULL)
00050                 return NULL;
00051 
00052         end = src + len;
00053         in = src;
00054         pos = out;
00055         line_len = 0;
00056         while (end - in >= 3) {
00057                 *pos++ = base64_table[in[0] >> 2];
00058                 *pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
00059                 *pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
00060                 *pos++ = base64_table[in[2] & 0x3f];
00061                 in += 3;
00062                 line_len += 4;
00063                 if (line_len >= 72) {
00064                         *pos++ = '\n';
00065                         line_len = 0;
00066                 }
00067         }
00068 
00069         if (end - in) {
00070                 *pos++ = base64_table[in[0] >> 2];
00071                 if (end - in == 1) {
00072                         *pos++ = base64_table[(in[0] & 0x03) << 4];
00073                         *pos++ = '=';
00074                 } else {
00075                         *pos++ = base64_table[((in[0] & 0x03) << 4) |
00076                                               (in[1] >> 4)];
00077                         *pos++ = base64_table[(in[1] & 0x0f) << 2];
00078                 }
00079                 *pos++ = '=';
00080                 line_len += 4;
00081         }
00082 
00083         if (line_len)
00084                 *pos++ = '\n';
00085 
00086         *pos = '\0';
00087         if (out_len)
00088                 *out_len = pos - out;
00089         return out;
00090 }
00091 
00092 
00103 unsigned char * base64_decode(const unsigned char *src, size_t len,
00104                               size_t *out_len)
00105 {
00106         unsigned char dtable[256], *out, *pos, in[4], block[4], tmp;
00107         size_t i, count, olen;
00108 
00109         os_memset(dtable, 0x80, 256);
00110         for (i = 0; i < sizeof(base64_table) - 1; i++)
00111                 dtable[base64_table[i]] = (unsigned char) i;
00112         dtable['='] = 0;
00113 
00114         count = 0;
00115         for (i = 0; i < len; i++) {
00116                 if (dtable[src[i]] != 0x80)
00117                         count++;
00118         }
00119 
00120         if (count == 0 || count % 4)
00121                 return NULL;
00122 
00123         olen = count / 4 * 3;
00124         pos = out = os_malloc(olen);
00125         if (out == NULL)
00126                 return NULL;
00127 
00128         count = 0;
00129         for (i = 0; i < len; i++) {
00130                 tmp = dtable[src[i]];
00131                 if (tmp == 0x80)
00132                         continue;
00133 
00134                 in[count] = src[i];
00135                 block[count] = tmp;
00136                 count++;
00137                 if (count == 4) {
00138                         *pos++ = (block[0] << 2) | (block[1] >> 4);
00139                         *pos++ = (block[1] << 4) | (block[2] >> 2);
00140                         *pos++ = (block[2] << 6) | block[3];
00141                         count = 0;
00142                 }
00143         }
00144 
00145         if (pos > out) {
00146                 if (in[2] == '=')
00147                         pos -= 2;
00148                 else if (in[3] == '=')
00149                         pos--;
00150         }
00151 
00152         *out_len = pos - out;
00153         return out;
00154 }


wpa_supplicant_node
Author(s): Package maintained by Blaise Gassend
autogenerated on Thu Apr 24 2014 15:33:19