1238104Sdes/* 2238104Sdes * Copyright (c) 1996, 1998 by Internet Software Consortium. 3238104Sdes * 4238104Sdes * Permission to use, copy, modify, and distribute this software for any 5238104Sdes * purpose with or without fee is hereby granted, provided that the above 6238104Sdes * copyright notice and this permission notice appear in all copies. 7238104Sdes * 8238104Sdes * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS 9238104Sdes * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 10238104Sdes * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 11238104Sdes * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 12238104Sdes * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 13238104Sdes * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 14238104Sdes * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 15238104Sdes * SOFTWARE. 16238104Sdes */ 17238104Sdes 18238104Sdes/* 19238104Sdes * Portions Copyright (c) 1995 by International Business Machines, Inc. 20238104Sdes * 21238104Sdes * International Business Machines, Inc. (hereinafter called IBM) grants 22238104Sdes * permission under its copyrights to use, copy, modify, and distribute this 23238104Sdes * Software with or without fee, provided that the above copyright notice and 24238104Sdes * all paragraphs of this notice appear in all copies, and that the name of IBM 25238104Sdes * not be used in connection with the marketing of any product incorporating 26238104Sdes * the Software or modifications thereof, without specific, written prior 27238104Sdes * permission. 28238104Sdes * 29238104Sdes * To the extent it has a right to do so, IBM grants an immunity from suit 30238104Sdes * under its patents, if any, for the use, sale or manufacture of products to 31238104Sdes * the extent that such products are used for performing Domain Name System 32238104Sdes * dynamic updates in TCP/IP networks by means of the Software. No immunity is 33238104Sdes * granted for any product per se or for any other function of any product. 34238104Sdes * 35238104Sdes * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, 36238104Sdes * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 37238104Sdes * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, 38238104Sdes * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING 39238104Sdes * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN 40238104Sdes * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. 41238104Sdes */ 42238104Sdes#include <ldns/config.h> 43238104Sdes#include <ctype.h> 44238104Sdes#include <stdlib.h> 45238104Sdes#include <string.h> 46238104Sdes 47238104Sdesstatic const char Base64[] = 48238104Sdes "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 49238104Sdesstatic const char Pad64 = '='; 50238104Sdes 51238104Sdes/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) 52238104Sdes The following encoding technique is taken from RFC 1521 by Borenstein 53238104Sdes and Freed. It is reproduced here in a slightly edited form for 54238104Sdes convenience. 55238104Sdes 56238104Sdes A 65-character subset of US-ASCII is used, enabling 6 bits to be 57238104Sdes represented per printable character. (The extra 65th character, "=", 58238104Sdes is used to signify a special processing function.) 59238104Sdes 60238104Sdes The encoding process represents 24-bit groups of input bits as output 61238104Sdes strings of 4 encoded characters. Proceeding from left to right, a 62238104Sdes 24-bit input group is formed by concatenating 3 8-bit input groups. 63238104Sdes These 24 bits are then treated as 4 concatenated 6-bit groups, each 64238104Sdes of which is translated into a single digit in the base64 alphabet. 65238104Sdes 66238104Sdes Each 6-bit group is used as an index into an array of 64 printable 67238104Sdes characters. The character referenced by the index is placed in the 68238104Sdes output string. 69238104Sdes 70238104Sdes Table 1: The Base64 Alphabet 71238104Sdes 72238104Sdes Value Encoding Value Encoding Value Encoding Value Encoding 73238104Sdes 0 A 17 R 34 i 51 z 74238104Sdes 1 B 18 S 35 j 52 0 75238104Sdes 2 C 19 T 36 k 53 1 76238104Sdes 3 D 20 U 37 l 54 2 77238104Sdes 4 E 21 V 38 m 55 3 78238104Sdes 5 F 22 W 39 n 56 4 79238104Sdes 6 G 23 X 40 o 57 5 80238104Sdes 7 H 24 Y 41 p 58 6 81238104Sdes 8 I 25 Z 42 q 59 7 82238104Sdes 9 J 26 a 43 r 60 8 83238104Sdes 10 K 27 b 44 s 61 9 84238104Sdes 11 L 28 c 45 t 62 + 85238104Sdes 12 M 29 d 46 u 63 / 86238104Sdes 13 N 30 e 47 v 87238104Sdes 14 O 31 f 48 w (pad) = 88238104Sdes 15 P 32 g 49 x 89238104Sdes 16 Q 33 h 50 y 90238104Sdes 91238104Sdes Special processing is performed if fewer than 24 bits are available 92238104Sdes at the end of the data being encoded. A full encoding quantum is 93238104Sdes always completed at the end of a quantity. When fewer than 24 input 94238104Sdes bits are available in an input group, zero bits are added (on the 95238104Sdes right) to form an integral number of 6-bit groups. Padding at the 96238104Sdes end of the data is performed using the '=' character. 97238104Sdes 98238104Sdes Since all base64 input is an integral number of octets, only the 99238104Sdes ------------------------------------------------- 100238104Sdes following cases can arise: 101238104Sdes 102238104Sdes (1) the final quantum of encoding input is an integral 103238104Sdes multiple of 24 bits; here, the final unit of encoded 104238104Sdes output will be an integral multiple of 4 characters 105238104Sdes with no "=" padding, 106238104Sdes (2) the final quantum of encoding input is exactly 8 bits; 107238104Sdes here, the final unit of encoded output will be two 108238104Sdes characters followed by two "=" padding characters, or 109238104Sdes (3) the final quantum of encoding input is exactly 16 bits; 110238104Sdes here, the final unit of encoded output will be three 111238104Sdes characters followed by one "=" padding character. 112238104Sdes */ 113238104Sdes 114238104Sdesint 115238104Sdesldns_b64_ntop(uint8_t const *src, size_t srclength, char *target, size_t targsize) { 116238104Sdes size_t datalength = 0; 117238104Sdes uint8_t input[3]; 118238104Sdes uint8_t output[4]; 119238104Sdes size_t i; 120238104Sdes 121238104Sdes if (srclength == 0) { 122238104Sdes if (targsize > 0) { 123238104Sdes target[0] = '\0'; 124238104Sdes return 0; 125238104Sdes } else { 126238104Sdes return -1; 127238104Sdes } 128238104Sdes } 129238104Sdes 130238104Sdes while (2 < srclength) { 131238104Sdes input[0] = *src++; 132238104Sdes input[1] = *src++; 133238104Sdes input[2] = *src++; 134238104Sdes srclength -= 3; 135238104Sdes 136238104Sdes output[0] = input[0] >> 2; 137238104Sdes output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); 138238104Sdes output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); 139238104Sdes output[3] = input[2] & 0x3f; 140269257Sdes assert(output[0] < 64); 141269257Sdes assert(output[1] < 64); 142269257Sdes assert(output[2] < 64); 143269257Sdes assert(output[3] < 64); 144238104Sdes 145238104Sdes if (datalength + 4 > targsize) { 146238104Sdes return (-1); 147238104Sdes } 148238104Sdes target[datalength++] = Base64[output[0]]; 149238104Sdes target[datalength++] = Base64[output[1]]; 150238104Sdes target[datalength++] = Base64[output[2]]; 151238104Sdes target[datalength++] = Base64[output[3]]; 152238104Sdes } 153238104Sdes 154238104Sdes /* Now we worry about padding. */ 155238104Sdes if (0 != srclength) { 156238104Sdes /* Get what's left. */ 157238104Sdes input[0] = input[1] = input[2] = (uint8_t) '\0'; 158238104Sdes for (i = 0; i < srclength; i++) 159238104Sdes input[i] = *src++; 160238104Sdes 161238104Sdes output[0] = input[0] >> 2; 162238104Sdes output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); 163238104Sdes output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); 164269257Sdes assert(output[0] < 64); 165269257Sdes assert(output[1] < 64); 166269257Sdes assert(output[2] < 64); 167238104Sdes 168238104Sdes if (datalength + 4 > targsize) { 169238104Sdes return (-2); 170238104Sdes } 171238104Sdes target[datalength++] = Base64[output[0]]; 172238104Sdes target[datalength++] = Base64[output[1]]; 173238104Sdes if (srclength == 1) { 174238104Sdes target[datalength++] = Pad64; 175238104Sdes } else { 176238104Sdes target[datalength++] = Base64[output[2]]; 177238104Sdes } 178238104Sdes target[datalength++] = Pad64; 179238104Sdes } 180238104Sdes if (datalength >= targsize) { 181238104Sdes return (-3); 182238104Sdes } 183238104Sdes target[datalength] = '\0'; /* Returned value doesn't count \0. */ 184238104Sdes return (int) (datalength); 185238104Sdes} 186