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