Annotation of embedaddon/dhcp/dst/base64.c, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (c) 2004,2009 by Internet Systems Consortium, Inc. ("ISC")
! 3: * Copyright (c) 1996-2003 by Internet Software Consortium
! 4: *
! 5: * Permission to use, copy, modify, and distribute this software for any
! 6: * purpose with or without fee is hereby granted, provided that the above
! 7: * copyright notice and this permission notice appear in all copies.
! 8: *
! 9: * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
! 10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
! 11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
! 12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
! 13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
! 14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
! 15: * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
! 16: *
! 17: * Internet Systems Consortium, Inc.
! 18: * 950 Charter Street
! 19: * Redwood City, CA 94063
! 20: * <info@isc.org>
! 21: * https://www.isc.org/
! 22: */
! 23:
! 24: /*
! 25: * Portions Copyright (c) 1995 by International Business Machines, Inc.
! 26: *
! 27: * International Business Machines, Inc. (hereinafter called IBM) grants
! 28: * permission under its copyrights to use, copy, modify, and distribute this
! 29: * Software with or without fee, provided that the above copyright notice and
! 30: * all paragraphs of this notice appear in all copies, and that the name of IBM
! 31: * not be used in connection with the marketing of any product incorporating
! 32: * the Software or modifications thereof, without specific, written prior
! 33: * permission.
! 34: *
! 35: * To the extent it has a right to do so, IBM grants an immunity from suit
! 36: * under its patents, if any, for the use, sale or manufacture of products to
! 37: * the extent that such products are used for performing Domain Name System
! 38: * dynamic updates in TCP/IP networks by means of the Software. No immunity is
! 39: * granted for any product per se or for any other function of any product.
! 40: *
! 41: * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
! 42: * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
! 43: * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
! 44: * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
! 45: * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
! 46: * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
! 47: */
! 48:
! 49: #if !defined(LINT) && !defined(CODECENTER)
! 50: static const char rcsid[] = "$Id: base64.c,v 1.2.786.2 2009-07-24 22:04:52 sar Exp $";
! 51: #endif /* not lint */
! 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:
! 60: #include <ctype.h>
! 61: #include <stdio.h>
! 62: #include <stdlib.h>
! 63: #include <string.h>
! 64:
! 65: #include <sys/socket.h>
! 66:
! 67: #include "minires/minires.h"
! 68: #include "arpa/nameser.h"
! 69:
! 70: #define Assert(Cond) if (!(Cond)) abort()
! 71:
! 72: static const char Base64[] =
! 73: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
! 74: static const char Pad64 = '=';
! 75:
! 76: /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
! 77: The following encoding technique is taken from RFC 1521 by Borenstein
! 78: and Freed. It is reproduced here in a slightly edited form for
! 79: convenience.
! 80:
! 81: A 65-character subset of US-ASCII is used, enabling 6 bits to be
! 82: represented per printable character. (The extra 65th character, "=",
! 83: is used to signify a special processing function.)
! 84:
! 85: The encoding process represents 24-bit groups of input bits as output
! 86: strings of 4 encoded characters. Proceeding from left to right, a
! 87: 24-bit input group is formed by concatenating 3 8-bit input groups.
! 88: These 24 bits are then treated as 4 concatenated 6-bit groups, each
! 89: of which is translated into a single digit in the base64 alphabet.
! 90:
! 91: Each 6-bit group is used as an index into an array of 64 printable
! 92: characters. The character referenced by the index is placed in the
! 93: output string.
! 94:
! 95: Table 1: The Base64 Alphabet
! 96:
! 97: Value Encoding Value Encoding Value Encoding Value Encoding
! 98: 0 A 17 R 34 i 51 z
! 99: 1 B 18 S 35 j 52 0
! 100: 2 C 19 T 36 k 53 1
! 101: 3 D 20 U 37 l 54 2
! 102: 4 E 21 V 38 m 55 3
! 103: 5 F 22 W 39 n 56 4
! 104: 6 G 23 X 40 o 57 5
! 105: 7 H 24 Y 41 p 58 6
! 106: 8 I 25 Z 42 q 59 7
! 107: 9 J 26 a 43 r 60 8
! 108: 10 K 27 b 44 s 61 9
! 109: 11 L 28 c 45 t 62 +
! 110: 12 M 29 d 46 u 63 /
! 111: 13 N 30 e 47 v
! 112: 14 O 31 f 48 w (pad) =
! 113: 15 P 32 g 49 x
! 114: 16 Q 33 h 50 y
! 115:
! 116: Special processing is performed if fewer than 24 bits are available
! 117: at the end of the data being encoded. A full encoding quantum is
! 118: always completed at the end of a quantity. When fewer than 24 input
! 119: bits are available in an input group, zero bits are added (on the
! 120: right) to form an integral number of 6-bit groups. Padding at the
! 121: end of the data is performed using the '=' character.
! 122:
! 123: Since all base64 input is an integral number of octets, only the
! 124: -------------------------------------------------
! 125: following cases can arise:
! 126:
! 127: (1) the final quantum of encoding input is an integral
! 128: multiple of 24 bits; here, the final unit of encoded
! 129: output will be an integral multiple of 4 characters
! 130: with no "=" padding,
! 131: (2) the final quantum of encoding input is exactly 8 bits;
! 132: here, the final unit of encoded output will be two
! 133: characters followed by two "=" padding characters, or
! 134: (3) the final quantum of encoding input is exactly 16 bits;
! 135: here, the final unit of encoded output will be three
! 136: characters followed by one "=" padding character.
! 137: */
! 138:
! 139: int
! 140: b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) {
! 141: size_t datalength = 0;
! 142: u_char input[3];
! 143: u_char output[4];
! 144: size_t i;
! 145:
! 146: while (2 < srclength) {
! 147: input[0] = *src++;
! 148: input[1] = *src++;
! 149: input[2] = *src++;
! 150: srclength -= 3;
! 151:
! 152: output[0] = input[0] >> 2;
! 153: output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
! 154: output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
! 155: output[3] = input[2] & 0x3f;
! 156: Assert(output[0] < 64);
! 157: Assert(output[1] < 64);
! 158: Assert(output[2] < 64);
! 159: Assert(output[3] < 64);
! 160:
! 161: if (datalength + 4 > targsize)
! 162: return (-1);
! 163: target[datalength++] = Base64[output[0]];
! 164: target[datalength++] = Base64[output[1]];
! 165: target[datalength++] = Base64[output[2]];
! 166: target[datalength++] = Base64[output[3]];
! 167: }
! 168:
! 169: /* Now we worry about padding. */
! 170: if (0 != srclength) {
! 171: /* Get what's left. */
! 172: input[0] = input[1] = input[2] = '\0';
! 173: for (i = 0; i < srclength; i++)
! 174: input[i] = *src++;
! 175:
! 176: output[0] = input[0] >> 2;
! 177: output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
! 178: output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
! 179: Assert(output[0] < 64);
! 180: Assert(output[1] < 64);
! 181: Assert(output[2] < 64);
! 182:
! 183: if (datalength + 4 > targsize)
! 184: return (-1);
! 185: target[datalength++] = Base64[output[0]];
! 186: target[datalength++] = Base64[output[1]];
! 187: if (srclength == 1)
! 188: target[datalength++] = Pad64;
! 189: else
! 190: target[datalength++] = Base64[output[2]];
! 191: target[datalength++] = Pad64;
! 192: }
! 193: if (datalength >= targsize)
! 194: return (-1);
! 195: target[datalength] = '\0'; /* Returned value doesn't count \0. */
! 196: return (datalength);
! 197: }
! 198:
! 199: /* skips all whitespace anywhere.
! 200: converts characters, four at a time, starting at (or after)
! 201: src from base - 64 numbers into three 8 bit bytes in the target area.
! 202: it returns the number of data bytes stored at the target, or -1 on error.
! 203: */
! 204:
! 205: int
! 206: b64_pton(src, target, targsize)
! 207: char const *src;
! 208: u_char *target;
! 209: size_t targsize;
! 210: {
! 211: int tarindex, state, ch;
! 212: char *pos;
! 213:
! 214: state = 0;
! 215: tarindex = 0;
! 216:
! 217: while ((ch = *src++) != '\0') {
! 218: if (isspace(ch)) /* Skip whitespace anywhere. */
! 219: continue;
! 220:
! 221: if (ch == Pad64)
! 222: break;
! 223:
! 224: pos = strchr(Base64, ch);
! 225: if (pos == 0) /* A non-base64 character. */
! 226: return (-1);
! 227:
! 228: switch (state) {
! 229: case 0:
! 230: if (target) {
! 231: if ((size_t)tarindex >= targsize)
! 232: return (-1);
! 233: target[tarindex] = (pos - Base64) << 2;
! 234: }
! 235: state = 1;
! 236: break;
! 237: case 1:
! 238: if (target) {
! 239: if ((size_t)tarindex + 1 >= targsize)
! 240: return (-1);
! 241: target[tarindex] |= (pos - Base64) >> 4;
! 242: target[tarindex+1] = ((pos - Base64) & 0x0f)
! 243: << 4 ;
! 244: }
! 245: tarindex++;
! 246: state = 2;
! 247: break;
! 248: case 2:
! 249: if (target) {
! 250: if ((size_t)tarindex + 1 >= targsize)
! 251: return (-1);
! 252: target[tarindex] |= (pos - Base64) >> 2;
! 253: target[tarindex+1] = ((pos - Base64) & 0x03)
! 254: << 6;
! 255: }
! 256: tarindex++;
! 257: state = 3;
! 258: break;
! 259: case 3:
! 260: if (target) {
! 261: if ((size_t)tarindex >= targsize)
! 262: return (-1);
! 263: target[tarindex] |= (pos - Base64);
! 264: }
! 265: tarindex++;
! 266: state = 0;
! 267: break;
! 268: default:
! 269: abort();
! 270: }
! 271: }
! 272:
! 273: /*
! 274: * We are done decoding Base-64 chars. Let's see if we ended
! 275: * on a byte boundary, and/or with erroneous trailing characters.
! 276: */
! 277:
! 278: if (ch == Pad64) { /* We got a pad char. */
! 279: ch = *src++; /* Skip it, get next. */
! 280: switch (state) {
! 281: case 0: /* Invalid = in first position */
! 282: case 1: /* Invalid = in second position */
! 283: return (-1);
! 284:
! 285: case 2: /* Valid, means one byte of info */
! 286: /* Skip any number of spaces. */
! 287: for ((void)NULL; ch != '\0'; ch = *src++)
! 288: if (!isspace(ch))
! 289: break;
! 290: /* Make sure there is another trailing = sign. */
! 291: if (ch != Pad64)
! 292: return (-1);
! 293: ch = *src++; /* Skip the = */
! 294: /* Fall through to "single trailing =" case. */
! 295: /* FALLTHROUGH */
! 296:
! 297: case 3: /* Valid, means two bytes of info */
! 298: /*
! 299: * We know this char is an =. Is there anything but
! 300: * whitespace after it?
! 301: */
! 302: for ((void)NULL; ch != '\0'; ch = *src++)
! 303: if (!isspace(ch))
! 304: return (-1);
! 305:
! 306: /*
! 307: * Now make sure for cases 2 and 3 that the "extra"
! 308: * bits that slopped past the last full byte were
! 309: * zeros. If we don't check them, they become a
! 310: * subliminal channel.
! 311: */
! 312: if (target && target[tarindex] != 0)
! 313: return (-1);
! 314: }
! 315: } else {
! 316: /*
! 317: * We ended by seeing the end of the string. Make sure we
! 318: * have no partial bytes lying around.
! 319: */
! 320: if (state != 0)
! 321: return (-1);
! 322: }
! 323:
! 324: return (tarindex);
! 325: }
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