1/* 2 * Copyright (c) 1996-1999 by Internet Software Consortium. 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS 9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 15 * SOFTWARE. 16 */ 17 18/* 19 * Portions Copyright (c) 1995 by International Business Machines, Inc. 20 * 21 * International Business Machines, Inc. (hereinafter called IBM) grants 22 * permission under its copyrights to use, copy, modify, and distribute this 23 * Software with or without fee, provided that the above copyright notice and 24 * all paragraphs of this notice appear in all copies, and that the name of IBM 25 * not be used in connection with the marketing of any product incorporating 26 * the Software or modifications thereof, without specific, written prior 27 * permission. 28 * 29 * To the extent it has a right to do so, IBM grants an immunity from suit 30 * under its patents, if any, for the use, sale or manufacture of products to 31 * the extent that such products are used for performing Domain Name System 32 * dynamic updates in TCP/IP networks by means of the Software. No immunity is 33 * granted for any product per se or for any other function of any product. 34 * 35 * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, 36 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 37 * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, 38 * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING 39 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN 40 * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. 41 */ 42 43#ifndef __APPLE__ 44#if !defined(LINT) && !defined(CODECENTER) 45static const char rcsid[] = "$Id: base64.c,v 1.1 2006/03/01 19:01:34 majka Exp $"; 46#endif /* not lint */ 47#endif 48 49#ifndef __APPLE__ 50#include "port_before.h" 51#endif 52 53#include <sys/types.h> 54#include <sys/param.h> 55#include <sys/socket.h> 56 57#include <netinet/in.h> 58#include <arpa/inet.h> 59#include <arpa/nameser.h> 60 61#include <ctype.h> 62#include <resolv.h> 63#include <stdio.h> 64#include <stdlib.h> 65#include <string.h> 66 67#ifndef __APPLE__ 68#include "port_after.h" 69#endif 70 71#define Assert(Cond) if (!(Cond)) abort() 72 73static const char Base64[] = 74 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 75static const char Pad64 = '='; 76 77/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) 78 The following encoding technique is taken from RFC 1521 by Borenstein 79 and Freed. It is reproduced here in a slightly edited form for 80 convenience. 81 82 A 65-character subset of US-ASCII is used, enabling 6 bits to be 83 represented per printable character. (The extra 65th character, "=", 84 is used to signify a special processing function.) 85 86 The encoding process represents 24-bit groups of input bits as output 87 strings of 4 encoded characters. Proceeding from left to right, a 88 24-bit input group is formed by concatenating 3 8-bit input groups. 89 These 24 bits are then treated as 4 concatenated 6-bit groups, each 90 of which is translated into a single digit in the base64 alphabet. 91 92 Each 6-bit group is used as an index into an array of 64 printable 93 characters. The character referenced by the index is placed in the 94 output string. 95 96 Table 1: The Base64 Alphabet 97 98 Value Encoding Value Encoding Value Encoding Value Encoding 99 0 A 17 R 34 i 51 z 100 1 B 18 S 35 j 52 0 101 2 C 19 T 36 k 53 1 102 3 D 20 U 37 l 54 2 103 4 E 21 V 38 m 55 3 104 5 F 22 W 39 n 56 4 105 6 G 23 X 40 o 57 5 106 7 H 24 Y 41 p 58 6 107 8 I 25 Z 42 q 59 7 108 9 J 26 a 43 r 60 8 109 10 K 27 b 44 s 61 9 110 11 L 28 c 45 t 62 + 111 12 M 29 d 46 u 63 / 112 13 N 30 e 47 v 113 14 O 31 f 48 w (pad) = 114 15 P 32 g 49 x 115 16 Q 33 h 50 y 116 117 Special processing is performed if fewer than 24 bits are available 118 at the end of the data being encoded. A full encoding quantum is 119 always completed at the end of a quantity. When fewer than 24 input 120 bits are available in an input group, zero bits are added (on the 121 right) to form an integral number of 6-bit groups. Padding at the 122 end of the data is performed using the '=' character. 123 124 Since all base64 input is an integral number of octets, only the 125 ------------------------------------------------- 126 following cases can arise: 127 128 (1) the final quantum of encoding input is an integral 129 multiple of 24 bits; here, the final unit of encoded 130 output will be an integral multiple of 4 characters 131 with no "=" padding, 132 (2) the final quantum of encoding input is exactly 8 bits; 133 here, the final unit of encoded output will be two 134 characters followed by two "=" padding characters, or 135 (3) the final quantum of encoding input is exactly 16 bits; 136 here, the final unit of encoded output will be three 137 characters followed by one "=" padding character. 138 */ 139 140int 141b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) { 142 size_t datalength = 0; 143 u_char input[3]; 144 u_char output[4]; 145 size_t i; 146 147 while (2 < srclength) { 148 input[0] = *src++; 149 input[1] = *src++; 150 input[2] = *src++; 151 srclength -= 3; 152 153 output[0] = input[0] >> 2; 154 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); 155 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); 156 output[3] = input[2] & 0x3f; 157 Assert(output[0] < 64); 158 Assert(output[1] < 64); 159 Assert(output[2] < 64); 160 Assert(output[3] < 64); 161 162 if (datalength + 4 > targsize) 163 return (-1); 164 target[datalength++] = Base64[output[0]]; 165 target[datalength++] = Base64[output[1]]; 166 target[datalength++] = Base64[output[2]]; 167 target[datalength++] = Base64[output[3]]; 168 } 169 170 /* Now we worry about padding. */ 171 if (0 != srclength) { 172 /* Get what's left. */ 173 input[0] = input[1] = input[2] = '\0'; 174 for (i = 0; i < srclength; i++) 175 input[i] = *src++; 176 177 output[0] = input[0] >> 2; 178 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); 179 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); 180 Assert(output[0] < 64); 181 Assert(output[1] < 64); 182 Assert(output[2] < 64); 183 184 if (datalength + 4 > targsize) 185 return (-1); 186 target[datalength++] = Base64[output[0]]; 187 target[datalength++] = Base64[output[1]]; 188 if (srclength == 1) 189 target[datalength++] = Pad64; 190 else 191 target[datalength++] = Base64[output[2]]; 192 target[datalength++] = Pad64; 193 } 194 if (datalength >= targsize) 195 return (-1); 196 target[datalength] = '\0'; /* Returned value doesn't count \0. */ 197 return (datalength); 198} 199 200/* skips all whitespace anywhere. 201 converts characters, four at a time, starting at (or after) 202 src from base - 64 numbers into three 8 bit bytes in the target area. 203 it returns the number of data bytes stored at the target, or -1 on error. 204 */ 205 206int 207b64_pton(src, target, targsize) 208 char const *src; 209 u_char *target; 210 size_t targsize; 211{ 212 int tarindex, state, ch; 213 char *pos; 214 215 state = 0; 216 tarindex = 0; 217 218 while ((ch = *src++) != '\0') { 219 if (isspace(ch)) /* Skip whitespace anywhere. */ 220 continue; 221 222 if (ch == Pad64) 223 break; 224 225 pos = strchr(Base64, ch); 226 if (pos == 0) /* A non-base64 character. */ 227 return (-1); 228 229 switch (state) { 230 case 0: 231 if (target) { 232 if ((size_t)tarindex >= targsize) 233 return (-1); 234 target[tarindex] = (pos - Base64) << 2; 235 } 236 state = 1; 237 break; 238 case 1: 239 if (target) { 240 if ((size_t)tarindex + 1 >= targsize) 241 return (-1); 242 target[tarindex] |= (pos - Base64) >> 4; 243 target[tarindex+1] = ((pos - Base64) & 0x0f) 244 << 4 ; 245 } 246 tarindex++; 247 state = 2; 248 break; 249 case 2: 250 if (target) { 251 if ((size_t)tarindex + 1 >= targsize) 252 return (-1); 253 target[tarindex] |= (pos - Base64) >> 2; 254 target[tarindex+1] = ((pos - Base64) & 0x03) 255 << 6; 256 } 257 tarindex++; 258 state = 3; 259 break; 260 case 3: 261 if (target) { 262 if ((size_t)tarindex >= targsize) 263 return (-1); 264 target[tarindex] |= (pos - Base64); 265 } 266 tarindex++; 267 state = 0; 268 break; 269 default: 270 abort(); 271 } 272 } 273 274 /* 275 * We are done decoding Base-64 chars. Let's see if we ended 276 * on a byte boundary, and/or with erroneous trailing characters. 277 */ 278 279 if (ch == Pad64) { /* We got a pad char. */ 280 ch = *src++; /* Skip it, get next. */ 281 switch (state) { 282 case 0: /* Invalid = in first position */ 283 case 1: /* Invalid = in second position */ 284 return (-1); 285 286 case 2: /* Valid, means one byte of info */ 287 /* Skip any number of spaces. */ 288 for ((void)NULL; ch != '\0'; ch = *src++) 289 if (!isspace(ch)) 290 break; 291 /* Make sure there is another trailing = sign. */ 292 if (ch != Pad64) 293 return (-1); 294 ch = *src++; /* Skip the = */ 295 /* Fall through to "single trailing =" case. */ 296 /* FALLTHROUGH */ 297 298 case 3: /* Valid, means two bytes of info */ 299 /* 300 * We know this char is an =. Is there anything but 301 * whitespace after it? 302 */ 303 for ((void)NULL; ch != '\0'; ch = *src++) 304 if (!isspace(ch)) 305 return (-1); 306 307 /* 308 * Now make sure for cases 2 and 3 that the "extra" 309 * bits that slopped past the last full byte were 310 * zeros. If we don't check them, they become a 311 * subliminal channel. 312 */ 313 if (target && target[tarindex] != 0) 314 return (-1); 315 } 316 } else { 317 /* 318 * We ended by seeing the end of the string. Make sure we 319 * have no partial bytes lying around. 320 */ 321 if (state != 0) 322 return (-1); 323 } 324 325 return (tarindex); 326} 327