1 /* 2 * Copyright (c) 1995-2001 Kungliga Tekniska H�gskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the Institute nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <stdlib.h> 35 #include <string.h> 36 37 #include "dma.h" 38 39 static char base64_chars[] = 40 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 41 42 static int 43 pos(char c) 44 { 45 char *p; 46 for (p = base64_chars; *p; p++) 47 if (*p == c) 48 return p - base64_chars; 49 return -1; 50 } 51 52 53 int 54 base64_encode(const void *data, int size, char **str) 55 { 56 char *s, *p; 57 int i; 58 int c; 59 const unsigned char *q; 60 61 p = s = (char *) malloc(size * 4 / 3 + 4); 62 if (p == NULL) 63 return -1; 64 q = (const unsigned char *) data; 65 i = 0; 66 for (i = 0; i < size;) { 67 c = q[i++]; 68 c *= 256; 69 if (i < size) 70 c += q[i]; 71 i++; 72 c *= 256; 73 if (i < size) 74 c += q[i]; 75 i++; 76 p[0] = base64_chars[(c & 0x00fc0000) >> 18]; 77 p[1] = base64_chars[(c & 0x0003f000) >> 12]; 78 p[2] = base64_chars[(c & 0x00000fc0) >> 6]; 79 p[3] = base64_chars[(c & 0x0000003f) >> 0]; 80 if (i > size) 81 p[3] = '='; 82 if (i > size + 1) 83 p[2] = '='; 84 p += 4; 85 } 86 *p = 0; 87 *str = s; 88 return strlen(s); 89 } 90 91 #define DECODE_ERROR 0xffffffff 92 93 static unsigned int 94 token_decode(const char *token) 95 { 96 int i; 97 unsigned int val = 0; 98 int marker = 0; 99 if (strlen(token) < 4) 100 return DECODE_ERROR; 101 for (i = 0; i < 4; i++) { 102 val *= 64; 103 if (token[i] == '=') 104 marker++; 105 else if (marker > 0) 106 return DECODE_ERROR; 107 else 108 val += pos(token[i]); 109 } 110 if (marker > 2) 111 return DECODE_ERROR; 112 return (marker << 24) | val; 113 } 114 115 int 116 base64_decode(const char *str, void *data) 117 { 118 const char *p; 119 unsigned char *q; 120 121 q = data; 122 for (p = str; *p && (*p == '=' || strchr(base64_chars, *p)); p += 4) { 123 unsigned int val = token_decode(p); 124 unsigned int marker = (val >> 24) & 0xff; 125 if (val == DECODE_ERROR) 126 return -1; 127 *q++ = (val >> 16) & 0xff; 128 if (marker < 2) 129 *q++ = (val >> 8) & 0xff; 130 if (marker < 1) 131 *q++ = val & 0xff; 132 } 133 return q - (unsigned char *) data; 134 } 135 136