Annotation of embedaddon/tmux/compat/base64.c, revision 1.1
1.1 ! misho 1: /* $OpenBSD: base64.c,v 1.8 2015/01/16 16:48:51 deraadt Exp $ */
! 2:
! 3: /*
! 4: * Copyright (c) 1996 by Internet Software Consortium.
! 5: *
! 6: * Permission to use, copy, modify, and distribute this software for any
! 7: * purpose with or without fee is hereby granted, provided that the above
! 8: * copyright notice and this permission notice appear in all copies.
! 9: *
! 10: * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
! 11: * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
! 12: * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
! 13: * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
! 14: * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
! 15: * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
! 16: * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
! 17: * SOFTWARE.
! 18: */
! 19:
! 20: /*
! 21: * Portions Copyright (c) 1995 by International Business Machines, Inc.
! 22: *
! 23: * International Business Machines, Inc. (hereinafter called IBM) grants
! 24: * permission under its copyrights to use, copy, modify, and distribute this
! 25: * Software with or without fee, provided that the above copyright notice and
! 26: * all paragraphs of this notice appear in all copies, and that the name of IBM
! 27: * not be used in connection with the marketing of any product incorporating
! 28: * the Software or modifications thereof, without specific, written prior
! 29: * permission.
! 30: *
! 31: * To the extent it has a right to do so, IBM grants an immunity from suit
! 32: * under its patents, if any, for the use, sale or manufacture of products to
! 33: * the extent that such products are used for performing Domain Name System
! 34: * dynamic updates in TCP/IP networks by means of the Software. No immunity is
! 35: * granted for any product per se or for any other function of any product.
! 36: *
! 37: * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
! 38: * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
! 39: * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
! 40: * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
! 41: * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
! 42: * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
! 43: */
! 44:
! 45: #include <sys/types.h>
! 46: #include <sys/socket.h>
! 47: #include <netinet/in.h>
! 48: #include <arpa/inet.h>
! 49: #include <arpa/nameser.h>
! 50:
! 51: #include <ctype.h>
! 52: #include <resolv.h>
! 53: #include <stdio.h>
! 54:
! 55: #include <stdlib.h>
! 56: #include <string.h>
! 57:
! 58: static const char Base64[] =
! 59: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
! 60: static const char Pad64 = '=';
! 61:
! 62: /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
! 63: The following encoding technique is taken from RFC 1521 by Borenstein
! 64: and Freed. It is reproduced here in a slightly edited form for
! 65: convenience.
! 66:
! 67: A 65-character subset of US-ASCII is used, enabling 6 bits to be
! 68: represented per printable character. (The extra 65th character, "=",
! 69: is used to signify a special processing function.)
! 70:
! 71: The encoding process represents 24-bit groups of input bits as output
! 72: strings of 4 encoded characters. Proceeding from left to right, a
! 73: 24-bit input group is formed by concatenating 3 8-bit input groups.
! 74: These 24 bits are then treated as 4 concatenated 6-bit groups, each
! 75: of which is translated into a single digit in the base64 alphabet.
! 76:
! 77: Each 6-bit group is used as an index into an array of 64 printable
! 78: characters. The character referenced by the index is placed in the
! 79: output string.
! 80:
! 81: Table 1: The Base64 Alphabet
! 82:
! 83: Value Encoding Value Encoding Value Encoding Value Encoding
! 84: 0 A 17 R 34 i 51 z
! 85: 1 B 18 S 35 j 52 0
! 86: 2 C 19 T 36 k 53 1
! 87: 3 D 20 U 37 l 54 2
! 88: 4 E 21 V 38 m 55 3
! 89: 5 F 22 W 39 n 56 4
! 90: 6 G 23 X 40 o 57 5
! 91: 7 H 24 Y 41 p 58 6
! 92: 8 I 25 Z 42 q 59 7
! 93: 9 J 26 a 43 r 60 8
! 94: 10 K 27 b 44 s 61 9
! 95: 11 L 28 c 45 t 62 +
! 96: 12 M 29 d 46 u 63 /
! 97: 13 N 30 e 47 v
! 98: 14 O 31 f 48 w (pad) =
! 99: 15 P 32 g 49 x
! 100: 16 Q 33 h 50 y
! 101:
! 102: Special processing is performed if fewer than 24 bits are available
! 103: at the end of the data being encoded. A full encoding quantum is
! 104: always completed at the end of a quantity. When fewer than 24 input
! 105: bits are available in an input group, zero bits are added (on the
! 106: right) to form an integral number of 6-bit groups. Padding at the
! 107: end of the data is performed using the '=' character.
! 108:
! 109: Since all base64 input is an integral number of octets, only the
! 110: -------------------------------------------------
! 111: following cases can arise:
! 112:
! 113: (1) the final quantum of encoding input is an integral
! 114: multiple of 24 bits; here, the final unit of encoded
! 115: output will be an integral multiple of 4 characters
! 116: with no "=" padding,
! 117: (2) the final quantum of encoding input is exactly 8 bits;
! 118: here, the final unit of encoded output will be two
! 119: characters followed by two "=" padding characters, or
! 120: (3) the final quantum of encoding input is exactly 16 bits;
! 121: here, the final unit of encoded output will be three
! 122: characters followed by one "=" padding character.
! 123: */
! 124:
! 125: int
! 126: b64_ntop(src, srclength, target, targsize)
! 127: u_char const *src;
! 128: size_t srclength;
! 129: char *target;
! 130: size_t targsize;
! 131: {
! 132: size_t datalength = 0;
! 133: u_char input[3];
! 134: u_char output[4];
! 135: int i;
! 136:
! 137: while (2 < srclength) {
! 138: input[0] = *src++;
! 139: input[1] = *src++;
! 140: input[2] = *src++;
! 141: srclength -= 3;
! 142:
! 143: output[0] = input[0] >> 2;
! 144: output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
! 145: output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
! 146: output[3] = input[2] & 0x3f;
! 147:
! 148: if (datalength + 4 > targsize)
! 149: return (-1);
! 150: target[datalength++] = Base64[output[0]];
! 151: target[datalength++] = Base64[output[1]];
! 152: target[datalength++] = Base64[output[2]];
! 153: target[datalength++] = Base64[output[3]];
! 154: }
! 155:
! 156: /* Now we worry about padding. */
! 157: if (0 != srclength) {
! 158: /* Get what's left. */
! 159: input[0] = input[1] = input[2] = '\0';
! 160: for (i = 0; i < srclength; i++)
! 161: input[i] = *src++;
! 162:
! 163: output[0] = input[0] >> 2;
! 164: output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
! 165: output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
! 166:
! 167: if (datalength + 4 > targsize)
! 168: return (-1);
! 169: target[datalength++] = Base64[output[0]];
! 170: target[datalength++] = Base64[output[1]];
! 171: if (srclength == 1)
! 172: target[datalength++] = Pad64;
! 173: else
! 174: target[datalength++] = Base64[output[2]];
! 175: target[datalength++] = Pad64;
! 176: }
! 177: if (datalength >= targsize)
! 178: return (-1);
! 179: target[datalength] = '\0'; /* Returned value doesn't count \0. */
! 180: return (datalength);
! 181: }
! 182:
! 183: /* skips all whitespace anywhere.
! 184: converts characters, four at a time, starting at (or after)
! 185: src from base - 64 numbers into three 8 bit bytes in the target area.
! 186: it returns the number of data bytes stored at the target, or -1 on error.
! 187: */
! 188:
! 189: int
! 190: b64_pton(src, target, targsize)
! 191: char const *src;
! 192: u_char *target;
! 193: size_t targsize;
! 194: {
! 195: int tarindex, state, ch;
! 196: u_char nextbyte;
! 197: char *pos;
! 198:
! 199: state = 0;
! 200: tarindex = 0;
! 201:
! 202: while ((ch = (unsigned char)*src++) != '\0') {
! 203: if (isspace(ch)) /* Skip whitespace anywhere. */
! 204: continue;
! 205:
! 206: if (ch == Pad64)
! 207: break;
! 208:
! 209: pos = strchr(Base64, ch);
! 210: if (pos == 0) /* A non-base64 character. */
! 211: return (-1);
! 212:
! 213: switch (state) {
! 214: case 0:
! 215: if (target) {
! 216: if (tarindex >= targsize)
! 217: return (-1);
! 218: target[tarindex] = (pos - Base64) << 2;
! 219: }
! 220: state = 1;
! 221: break;
! 222: case 1:
! 223: if (target) {
! 224: if (tarindex >= targsize)
! 225: return (-1);
! 226: target[tarindex] |= (pos - Base64) >> 4;
! 227: nextbyte = ((pos - Base64) & 0x0f) << 4;
! 228: if (tarindex + 1 < targsize)
! 229: target[tarindex+1] = nextbyte;
! 230: else if (nextbyte)
! 231: return (-1);
! 232: }
! 233: tarindex++;
! 234: state = 2;
! 235: break;
! 236: case 2:
! 237: if (target) {
! 238: if (tarindex >= targsize)
! 239: return (-1);
! 240: target[tarindex] |= (pos - Base64) >> 2;
! 241: nextbyte = ((pos - Base64) & 0x03) << 6;
! 242: if (tarindex + 1 < targsize)
! 243: target[tarindex+1] = nextbyte;
! 244: else if (nextbyte)
! 245: return (-1);
! 246: }
! 247: tarindex++;
! 248: state = 3;
! 249: break;
! 250: case 3:
! 251: if (target) {
! 252: if (tarindex >= targsize)
! 253: return (-1);
! 254: target[tarindex] |= (pos - Base64);
! 255: }
! 256: tarindex++;
! 257: state = 0;
! 258: break;
! 259: }
! 260: }
! 261:
! 262: /*
! 263: * We are done decoding Base-64 chars. Let's see if we ended
! 264: * on a byte boundary, and/or with erroneous trailing characters.
! 265: */
! 266:
! 267: if (ch == Pad64) { /* We got a pad char. */
! 268: ch = (unsigned char)*src++; /* Skip it, get next. */
! 269: switch (state) {
! 270: case 0: /* Invalid = in first position */
! 271: case 1: /* Invalid = in second position */
! 272: return (-1);
! 273:
! 274: case 2: /* Valid, means one byte of info */
! 275: /* Skip any number of spaces. */
! 276: for (; ch != '\0'; ch = (unsigned char)*src++)
! 277: if (!isspace(ch))
! 278: break;
! 279: /* Make sure there is another trailing = sign. */
! 280: if (ch != Pad64)
! 281: return (-1);
! 282: ch = (unsigned char)*src++; /* Skip the = */
! 283: /* Fall through to "single trailing =" case. */
! 284: /* FALLTHROUGH */
! 285:
! 286: case 3: /* Valid, means two bytes of info */
! 287: /*
! 288: * We know this char is an =. Is there anything but
! 289: * whitespace after it?
! 290: */
! 291: for (; ch != '\0'; ch = (unsigned char)*src++)
! 292: if (!isspace(ch))
! 293: return (-1);
! 294:
! 295: /*
! 296: * Now make sure for cases 2 and 3 that the "extra"
! 297: * bits that slopped past the last full byte were
! 298: * zeros. If we don't check them, they become a
! 299: * subliminal channel.
! 300: */
! 301: if (target && tarindex < targsize &&
! 302: target[tarindex] != 0)
! 303: return (-1);
! 304: }
! 305: } else {
! 306: /*
! 307: * We ended by seeing the end of the string. Make sure we
! 308: * have no partial bytes lying around.
! 309: */
! 310: if (state != 0)
! 311: return (-1);
! 312: }
! 313:
! 314: return (tarindex);
! 315: }
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