1254721Semaste/* $NetBSD: base64.c,v 1.1.1.4 2009/04/12 16:35:49 christos Exp $ */ 2254721Semaste 3254721Semaste/* 4254721Semaste * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5254721Semaste * Copyright (c) 1996-1999 by Internet Software Consortium. 6254721Semaste * 7254721Semaste * Permission to use, copy, modify, and distribute this software for any 8254721Semaste * purpose with or without fee is hereby granted, provided that the above 9254721Semaste * copyright notice and this permission notice appear in all copies. 10254721Semaste * 11254721Semaste * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 12254721Semaste * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13254721Semaste * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14254721Semaste * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15254721Semaste * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16254721Semaste * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17254721Semaste * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18263363Semaste */ 19254721Semaste 20254721Semaste/* 21254721Semaste * Portions Copyright (c) 1995 by International Business Machines, Inc. 22263363Semaste * 23254721Semaste * International Business Machines, Inc. (hereinafter called IBM) grants 24254721Semaste * permission under its copyrights to use, copy, modify, and distribute this 25254721Semaste * Software with or without fee, provided that the above copyright notice and 26254721Semaste * all paragraphs of this notice appear in all copies, and that the name of IBM 27254721Semaste * not be used in connection with the marketing of any product incorporating 28254721Semaste * the Software or modifications thereof, without specific, written prior 29254721Semaste * permission. 30254721Semaste * 31254721Semaste * To the extent it has a right to do so, IBM grants an immunity from suit 32254721Semaste * under its patents, if any, for the use, sale or manufacture of products to 33254721Semaste * the extent that such products are used for performing Domain Name System 34254721Semaste * dynamic updates in TCP/IP networks by means of the Software. No immunity is 35254721Semaste * granted for any product per se or for any other function of any product. 36254721Semaste * 37254721Semaste * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, 38254721Semaste * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 39254721Semaste * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, 40254721Semaste * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING 41254721Semaste * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN 42254721Semaste * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. 43254721Semaste */ 44254721Semaste 45254721Semaste#include <sys/cdefs.h> 46254721Semaste#if defined(LIBC_SCCS) && !defined(lint) 47254721Semaste#if 0 48254721Semastestatic const char rcsid[] = "Id: base64.c,v 1.4 2005/04/27 04:56:34 sra Exp"; 49254721Semaste#else 50263363Semaste__RCSID("$NetBSD: base64.c,v 1.11 2008/06/21 20:41:48 christos Exp $"); 51254721Semaste#endif 52254721Semaste#endif /* LIBC_SCCS and not lint */ 53254721Semaste 54254721Semaste#include "port_before.h" 55254721Semaste 56254721Semaste#include <sys/types.h> 57254721Semaste#include <sys/param.h> 58254721Semaste#include <sys/socket.h> 59254721Semaste 60254721Semaste#include <netinet/in.h> 61254721Semaste#include <arpa/inet.h> 62254721Semaste#include <arpa/nameser.h> 63254721Semaste 64254721Semaste#include <assert.h> 65254721Semaste#include <ctype.h> 66254721Semaste#include <resolv.h> 67254721Semaste#include <stdio.h> 68254721Semaste#include <stdlib.h> 69254721Semaste#include <string.h> 70254721Semaste 71254721Semaste#include "port_after.h" 72254721Semaste 73254721Semaste#define Assert(Cond) if (!(Cond)) abort() 74254721Semaste 75254721Semastestatic const char Base64[] = 76254721Semaste "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 77254721Semastestatic const char Pad64 = '='; 78254721Semaste 79254721Semaste/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) 80254721Semaste The following encoding technique is taken from RFC1521 by Borenstein 81254721Semaste and Freed. It is reproduced here in a slightly edited form for 82254721Semaste convenience. 83254721Semaste 84254721Semaste A 65-character subset of US-ASCII is used, enabling 6 bits to be 85254721Semaste represented per printable character. (The extra 65th character, "=", 86254721Semaste is used to signify a special processing function.) 87254721Semaste 88254721Semaste The encoding process represents 24-bit groups of input bits as output 89254721Semaste strings of 4 encoded characters. Proceeding from left to right, a 90254721Semaste 24-bit input group is formed by concatenating 3 8-bit input groups. 91254721Semaste These 24 bits are then treated as 4 concatenated 6-bit groups, each 92254721Semaste of which is translated into a single digit in the base64 alphabet. 93254721Semaste 94254721Semaste Each 6-bit group is used as an index into an array of 64 printable 95254721Semaste characters. The character referenced by the index is placed in the 96254721Semaste output string. 97254721Semaste 98254721Semaste Table 1: The Base64 Alphabet 99254721Semaste 100254721Semaste Value Encoding Value Encoding Value Encoding Value Encoding 101254721Semaste 0 A 17 R 34 i 51 z 102254721Semaste 1 B 18 S 35 j 52 0 103254721Semaste 2 C 19 T 36 k 53 1 104254721Semaste 3 D 20 U 37 l 54 2 105254721Semaste 4 E 21 V 38 m 55 3 106254721Semaste 5 F 22 W 39 n 56 4 107254721Semaste 6 G 23 X 40 o 57 5 108254721Semaste 7 H 24 Y 41 p 58 6 109254721Semaste 8 I 25 Z 42 q 59 7 110254721Semaste 9 J 26 a 43 r 60 8 111254721Semaste 10 K 27 b 44 s 61 9 112254721Semaste 11 L 28 c 45 t 62 + 113254721Semaste 12 M 29 d 46 u 63 / 114254721Semaste 13 N 30 e 47 v 115254721Semaste 14 O 31 f 48 w (pad) = 116254721Semaste 15 P 32 g 49 x 117254721Semaste 16 Q 33 h 50 y 118254721Semaste 119254721Semaste Special processing is performed if fewer than 24 bits are available 120254721Semaste at the end of the data being encoded. A full encoding quantum is 121254721Semaste always completed at the end of a quantity. When fewer than 24 input 122254721Semaste bits are available in an input group, zero bits are added (on the 123254721Semaste right) to form an integral number of 6-bit groups. Padding at the 124254721Semaste end of the data is performed using the '=' character. 125254721Semaste 126254721Semaste Since all base64 input is an integral number of octets, only the 127254721Semaste ------------------------------------------------- 128254721Semaste following cases can arise: 129254721Semaste 130254721Semaste (1) the final quantum of encoding input is an integral 131254721Semaste multiple of 24 bits; here, the final unit of encoded 132254721Semaste output will be an integral multiple of 4 characters 133254721Semaste with no "=" padding, 134254721Semaste (2) the final quantum of encoding input is exactly 8 bits; 135254721Semaste here, the final unit of encoded output will be two 136254721Semaste characters followed by two "=" padding characters, or 137254721Semaste (3) the final quantum of encoding input is exactly 16 bits; 138254721Semaste here, the final unit of encoded output will be three 139254721Semaste characters followed by one "=" padding character. 140254721Semaste */ 141254721Semaste 142254721Semasteint 143254721Semasteb64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) { 144254721Semaste size_t datalength = 0; 145254721Semaste u_char input[3]; 146254721Semaste u_char output[4]; 147254721Semaste size_t i; 148254721Semaste 149254721Semaste _DIAGASSERT(src != NULL); 150254721Semaste _DIAGASSERT(target != NULL); 151254721Semaste 152254721Semaste while (2U < srclength) { 153254721Semaste input[0] = *src++; 154254721Semaste input[1] = *src++; 155254721Semaste input[2] = *src++; 156254721Semaste srclength -= 3; 157254721Semaste 158254721Semaste output[0] = (u_int32_t)input[0] >> 2; 159254721Semaste output[1] = ((u_int32_t)(input[0] & 0x03) << 4) + 160254721Semaste ((u_int32_t)input[1] >> 4); 161254721Semaste output[2] = ((u_int32_t)(input[1] & 0x0f) << 2) + 162254721Semaste ((u_int32_t)input[2] >> 6); 163254721Semaste output[3] = input[2] & 0x3f; 164254721Semaste Assert(output[0] < 64); 165254721Semaste Assert(output[1] < 64); 166254721Semaste Assert(output[2] < 64); 167254721Semaste Assert(output[3] < 64); 168254721Semaste 169254721Semaste if (datalength + 4 > targsize) 170254721Semaste return (-1); 171254721Semaste target[datalength++] = Base64[output[0]]; 172254721Semaste target[datalength++] = Base64[output[1]]; 173 target[datalength++] = Base64[output[2]]; 174 target[datalength++] = Base64[output[3]]; 175 } 176 177 /* Now we worry about padding. */ 178 if (0U != srclength) { 179 /* Get what's left. */ 180 input[0] = input[1] = input[2] = '\0'; 181 for (i = 0; i < srclength; i++) 182 input[i] = *src++; 183 184 output[0] = (u_int32_t)input[0] >> 2; 185 output[1] = ((u_int32_t)(input[0] & 0x03) << 4) + 186 ((u_int32_t)input[1] >> 4); 187 output[2] = ((u_int32_t)(input[1] & 0x0f) << 2) + 188 ((u_int32_t)input[2] >> 6); 189 Assert(output[0] < 64); 190 Assert(output[1] < 64); 191 Assert(output[2] < 64); 192 193 if (datalength + 4 > targsize) 194 return (-1); 195 target[datalength++] = Base64[output[0]]; 196 target[datalength++] = Base64[output[1]]; 197 if (srclength == 1U) 198 target[datalength++] = Pad64; 199 else 200 target[datalength++] = Base64[output[2]]; 201 target[datalength++] = Pad64; 202 } 203 if (datalength >= targsize) 204 return (-1); 205 target[datalength] = '\0'; /*%< Returned value doesn't count \\0. */ 206 return (datalength); 207} 208 209/* skips all whitespace anywhere. 210 converts characters, four at a time, starting at (or after) 211 src from base - 64 numbers into three 8 bit bytes in the target area. 212 it returns the number of data bytes stored at the target, or -1 on error. 213 */ 214 215int 216b64_pton(src, target, targsize) 217 char const *src; 218 u_char *target; 219 size_t targsize; 220{ 221 size_t tarindex; 222 int state, ch; 223 char *pos; 224 225 _DIAGASSERT(src != NULL); 226 _DIAGASSERT(target != NULL); 227 228 state = 0; 229 tarindex = 0; 230 231 while ((ch = (u_char) *src++) != '\0') { 232 if (isspace(ch)) /*%< Skip whitespace anywhere. */ 233 continue; 234 235 if (ch == Pad64) 236 break; 237 238 pos = strchr(Base64, ch); 239 if (pos == 0) /*%< A non-base64 character. */ 240 return (-1); 241 242 switch (state) { 243 case 0: 244 if (target) { 245 if ((size_t)tarindex >= targsize) 246 return (-1); 247 target[tarindex] = (pos - Base64) << 2; 248 } 249 state = 1; 250 break; 251 case 1: 252 if (target) { 253 if ((size_t)tarindex + 1 >= targsize) 254 return (-1); 255 target[tarindex] |= 256 (u_int32_t)(pos - Base64) >> 4; 257 target[tarindex+1] = ((pos - Base64) & 0x0f) 258 << 4 ; 259 } 260 tarindex++; 261 state = 2; 262 break; 263 case 2: 264 if (target) { 265 if ((size_t)tarindex + 1 >= targsize) 266 return (-1); 267 target[tarindex] |= 268 (u_int32_t)(pos - Base64) >> 2; 269 target[tarindex+1] = ((pos - Base64) & 0x03) 270 << 6; 271 } 272 tarindex++; 273 state = 3; 274 break; 275 case 3: 276 if (target) { 277 if ((size_t)tarindex >= targsize) 278 return (-1); 279 target[tarindex] |= (pos - Base64); 280 } 281 tarindex++; 282 state = 0; 283 break; 284 default: 285 abort(); 286 } 287 } 288 289 /* 290 * We are done decoding Base-64 chars. Let's see if we ended 291 * on a byte boundary, and/or with erroneous trailing characters. 292 */ 293 294 if (ch == Pad64) { /*%< We got a pad char. */ 295 ch = *src++; /*%< Skip it, get next. */ 296 switch (state) { 297 case 0: /*%< Invalid = in first position */ 298 case 1: /*%< Invalid = in second position */ 299 return (-1); 300 301 case 2: /*%< Valid, means one byte of info */ 302 /* Skip any number of spaces. */ 303 for (; ch != '\0'; ch = (u_char) *src++) 304 if (!isspace(ch)) 305 break; 306 /* Make sure there is another trailing = sign. */ 307 if (ch != Pad64) 308 return (-1); 309 ch = *src++; /*%< Skip the = */ 310 /* Fall through to "single trailing =" case. */ 311 /* FALLTHROUGH */ 312 313 case 3: /*%< Valid, means two bytes of info */ 314 /* 315 * We know this char is an =. Is there anything but 316 * whitespace after it? 317 */ 318 for (; ch != '\0'; ch = (u_char) *src++) 319 if (!isspace(ch)) 320 return (-1); 321 322 /* 323 * Now make sure for cases 2 and 3 that the "extra" 324 * bits that slopped past the last full byte were 325 * zeros. If we don't check them, they become a 326 * subliminal channel. 327 */ 328 if (target && target[tarindex] != 0) 329 return (-1); 330 } 331 } else { 332 /* 333 * We ended by seeing the end of the string. Make sure we 334 * have no partial bytes lying around. 335 */ 336 if (state != 0) 337 return (-1); 338 } 339 340 return (tarindex); 341} 342 343/*! \file */ 344