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 <config.h> 35 36#include <stdlib.h> 37#include <string.h> 38#include "base64.h" 39 40static const char base64_chars[] = 41 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 42 43static int 44pos(char c) 45{ 46 const char *p; 47 for (p = base64_chars; *p; p++) 48 if (*p == c) 49 return p - base64_chars; 50 return -1; 51} 52 53int ROKEN_LIB_FUNCTION 54base64_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 if (size > INT_MAX/4 || size < 0) { 62 *str = NULL; 63 return -1; 64 } 65 66 p = s = (char *) malloc(size * 4 / 3 + 4); 67 if (p == NULL) { 68 *str = NULL; 69 return -1; 70 } 71 q = (const unsigned char *) data; 72 73 for (i = 0; i < size;) { 74 c = q[i++]; 75 c *= 256; 76 if (i < size) 77 c += q[i]; 78 i++; 79 c *= 256; 80 if (i < size) 81 c += q[i]; 82 i++; 83 p[0] = base64_chars[(c & 0x00fc0000) >> 18]; 84 p[1] = base64_chars[(c & 0x0003f000) >> 12]; 85 p[2] = base64_chars[(c & 0x00000fc0) >> 6]; 86 p[3] = base64_chars[(c & 0x0000003f) >> 0]; 87 if (i > size) 88 p[3] = '='; 89 if (i > size + 1) 90 p[2] = '='; 91 p += 4; 92 } 93 *p = 0; 94 *str = s; 95 return strlen(s); 96} 97 98#define DECODE_ERROR 0xffffffff 99 100static unsigned int 101token_decode(const char *token) 102{ 103 int i; 104 unsigned int val = 0; 105 int marker = 0; 106 if (strlen(token) < 4) 107 return DECODE_ERROR; 108 for (i = 0; i < 4; i++) { 109 val *= 64; 110 if (token[i] == '=') 111 marker++; 112 else if (marker > 0) 113 return DECODE_ERROR; 114 else 115 val += pos(token[i]); 116 } 117 if (marker > 2) 118 return DECODE_ERROR; 119 return (marker << 24) | val; 120} 121 122int ROKEN_LIB_FUNCTION 123base64_decode(const char *str, void *data) 124{ 125 const char *p; 126 unsigned char *q; 127 128 q = data; 129 for (p = str; *p && (*p == '=' || strchr(base64_chars, *p)); p += 4) { 130 unsigned int val = token_decode(p); 131 unsigned int marker = (val >> 24) & 0xff; 132 if (val == DECODE_ERROR) 133 return -1; 134 *q++ = (val >> 16) & 0xff; 135 if (marker < 2) 136 *q++ = (val >> 8) & 0xff; 137 if (marker < 1) 138 *q++ = val & 0xff; 139 } 140 return q - (unsigned char *) data; 141} 142