1 /* 2 * Copyright (c) 1996, 1998 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 #include <ldns/config.h> 43 #ifndef HAVE_B64_NTOP 44 45 #include <sys/types.h> 46 #include <sys/param.h> 47 #ifdef HAVE_SYS_SOCKET_H 48 #include <sys/socket.h> 49 #endif 50 51 #ifdef HAVE_NETINET_IN_H 52 #include <netinet/in.h> 53 #endif 54 #ifdef HAVE_ARPA_INET_H 55 #include <arpa/inet.h> 56 #endif 57 58 #include <ctype.h> 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 63 #include <ldns/util.h> 64 65 #define Assert(Cond) if (!(Cond)) abort() 66 67 static const char Base64[] = 68 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 69 static const char Pad64 = '='; 70 71 /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) 72 The following encoding technique is taken from RFC 1521 by Borenstein 73 and Freed. It is reproduced here in a slightly edited form for 74 convenience. 75 76 A 65-character subset of US-ASCII is used, enabling 6 bits to be 77 represented per printable character. (The extra 65th character, "=", 78 is used to signify a special processing function.) 79 80 The encoding process represents 24-bit groups of input bits as output 81 strings of 4 encoded characters. Proceeding from left to right, a 82 24-bit input group is formed by concatenating 3 8-bit input groups. 83 These 24 bits are then treated as 4 concatenated 6-bit groups, each 84 of which is translated into a single digit in the base64 alphabet. 85 86 Each 6-bit group is used as an index into an array of 64 printable 87 characters. The character referenced by the index is placed in the 88 output string. 89 90 Table 1: The Base64 Alphabet 91 92 Value Encoding Value Encoding Value Encoding Value Encoding 93 0 A 17 R 34 i 51 z 94 1 B 18 S 35 j 52 0 95 2 C 19 T 36 k 53 1 96 3 D 20 U 37 l 54 2 97 4 E 21 V 38 m 55 3 98 5 F 22 W 39 n 56 4 99 6 G 23 X 40 o 57 5 100 7 H 24 Y 41 p 58 6 101 8 I 25 Z 42 q 59 7 102 9 J 26 a 43 r 60 8 103 10 K 27 b 44 s 61 9 104 11 L 28 c 45 t 62 + 105 12 M 29 d 46 u 63 / 106 13 N 30 e 47 v 107 14 O 31 f 48 w (pad) = 108 15 P 32 g 49 x 109 16 Q 33 h 50 y 110 111 Special processing is performed if fewer than 24 bits are available 112 at the end of the data being encoded. A full encoding quantum is 113 always completed at the end of a quantity. When fewer than 24 input 114 bits are available in an input group, zero bits are added (on the 115 right) to form an integral number of 6-bit groups. Padding at the 116 end of the data is performed using the '=' character. 117 118 Since all base64 input is an integral number of octets, only the 119 ------------------------------------------------- 120 following cases can arise: 121 122 (1) the final quantum of encoding input is an integral 123 multiple of 24 bits; here, the final unit of encoded 124 output will be an integral multiple of 4 characters 125 with no "=" padding, 126 (2) the final quantum of encoding input is exactly 8 bits; 127 here, the final unit of encoded output will be two 128 characters followed by two "=" padding characters, or 129 (3) the final quantum of encoding input is exactly 16 bits; 130 here, the final unit of encoded output will be three 131 characters followed by one "=" padding character. 132 */ 133 134 int 135 ldns_b64_ntop(uint8_t const *src, size_t srclength, char *target, size_t targsize) { 136 size_t datalength = 0; 137 uint8_t input[3]; 138 uint8_t output[4]; 139 size_t i; 140 141 if (srclength == 0) { 142 if (targsize > 0) { 143 target[0] = '\0'; 144 return 0; 145 } else { 146 return -1; 147 } 148 } 149 150 while (2 < srclength) { 151 input[0] = *src++; 152 input[1] = *src++; 153 input[2] = *src++; 154 srclength -= 3; 155 156 output[0] = input[0] >> 2; 157 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); 158 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); 159 output[3] = input[2] & 0x3f; 160 Assert(output[0] < 64); 161 Assert(output[1] < 64); 162 Assert(output[2] < 64); 163 Assert(output[3] < 64); 164 165 if (datalength + 4 > targsize) { 166 return (-1); 167 } 168 target[datalength++] = Base64[output[0]]; 169 target[datalength++] = Base64[output[1]]; 170 target[datalength++] = Base64[output[2]]; 171 target[datalength++] = Base64[output[3]]; 172 } 173 174 /* Now we worry about padding. */ 175 if (0 != srclength) { 176 /* Get what's left. */ 177 input[0] = input[1] = input[2] = (uint8_t) '\0'; 178 for (i = 0; i < srclength; i++) 179 input[i] = *src++; 180 181 output[0] = input[0] >> 2; 182 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); 183 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); 184 Assert(output[0] < 64); 185 Assert(output[1] < 64); 186 Assert(output[2] < 64); 187 188 if (datalength + 4 > targsize) { 189 return (-2); 190 } 191 target[datalength++] = Base64[output[0]]; 192 target[datalength++] = Base64[output[1]]; 193 if (srclength == 1) { 194 target[datalength++] = Pad64; 195 } else { 196 target[datalength++] = Base64[output[2]]; 197 } 198 target[datalength++] = Pad64; 199 } 200 if (datalength >= targsize) { 201 return (-3); 202 } 203 target[datalength] = '\0'; /* Returned value doesn't count \0. */ 204 return (int) (datalength); 205 } 206 207 #endif /* !HAVE_B64_NTOP */ 208