[101] | 1 | /*
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| 2 | * Copyright(c) 2010, Norio Kobota, All rights reserved.
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| 3 | */
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| 4 |
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| 5 | #include <string.h>
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| 6 | #include <stdlib.h>
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| 7 |
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| 8 | #include "base64.h"
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| 9 |
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| 10 | static const char base64_encode_chars[] =
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| 11 | "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
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| 12 | "abcdefghijklmnopqrstuvwxyz"
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| 13 | "0123456789+/";
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| 14 |
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| 15 | static const signed char base64_decode_chars[] = {
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| 16 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 17 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 18 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 19 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 20 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 21 | - 1, - 1, - 1, 62, - 1, - 1, - 1, 63,
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| 22 | 52, 53, 54, 55, 56, 57, 58, 59,
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| 23 | 60, 61, - 1, - 1, - 1, 0, - 1, - 1,
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| 24 | - 1, 0, 1, 2, 3, 4, 5, 6,
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| 25 | 7, 8, 9, 10, 11, 12, 13, 14,
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| 26 | 15, 16, 17, 18, 19, 20, 21, 22,
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| 27 | 23, 24, 25, - 1, - 1, - 1, - 1, - 1,
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| 28 | - 1, 26, 27, 28, 29, 30, 31, 32,
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| 29 | 33, 34, 35, 36, 37, 38, 39, 40,
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| 30 | 41, 42, 43, 44, 45, 46, 47, 48,
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| 31 | 49, 50, 51, - 1, - 1, - 1, - 1, - 1,
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| 32 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 33 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 34 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 35 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 36 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 37 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 38 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 39 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 40 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 41 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 42 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 43 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 44 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 45 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 46 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
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| 47 | - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1};
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| 48 |
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| 49 | int base64_encode(unsigned char *dst, size_t dstsiz, const unsigned char *src, size_t srcsiz) {
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| 50 | unsigned long x = 0UL;
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| 51 | int i = 0, l = 0;
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| 52 | unsigned char *pdst;
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| 53 |
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| 54 | pdst = dst;
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| 55 | for (; srcsiz > 0; src++, srcsiz--) {
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| 56 | x = x << 8 | *src;
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| 57 | for (l += 8; l >= 6; l -= 6) {
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| 58 | if (i >= dstsiz)
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| 59 | return -1;
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| 60 | pdst[i++] = base64_encode_chars[(x >> (l - 6)) & 0x3f];
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| 61 | }
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| 62 | }
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| 63 | if (l > 0) {
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| 64 | x <<= 6 - l;
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| 65 | if (i >= dstsiz)
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| 66 | return -1;
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| 67 | pdst[i++] = base64_encode_chars[x & 0x3f];
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| 68 | }
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| 69 | for (; i % 4;) {
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| 70 | if (i >= dstsiz)
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| 71 | return -1;
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| 72 | pdst[i++] = '=';
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| 73 | }
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| 74 | if (i >= dstsiz)
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| 75 | return -1;
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| 76 | pdst[i] = '\0';
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| 77 | return i;
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| 78 | }
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| 79 |
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| 80 | int base64_decode(unsigned char *dst, size_t dstsiz, const unsigned char *src) {
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| 81 | union {
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| 82 | unsigned long x;
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| 83 | char c[4];
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| 84 | } base64;
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| 85 | unsigned char *pdst;
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| 86 | int i, j = 0, k = 0;
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| 87 | size_t srcsiz = strlen((const char *)src);
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| 88 |
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| 89 | if ((srcsiz % 4) != 0) {
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| 90 | return -1;
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| 91 | }
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| 92 | base64.x = 0UL;
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| 93 | pdst = dst;
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| 94 | for (; srcsiz > 0; src+=4, srcsiz-=4) {
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| 95 | for (i = 0; i < 4; i++) {
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| 96 | if (base64_decode_chars[src[i]] == -1) {
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| 97 | return -1;
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| 98 | }
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| 99 | base64.x = base64.x << 6 | base64_decode_chars[src[i]];
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| 100 | j += (src[i] == '=');
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| 101 | }
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| 102 | for (i = 3; i > j; i--, k++) {
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| 103 | if (k >= dstsiz)
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| 104 | return -1;
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| 105 | *pdst++ = base64.c[i - 1];
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| 106 | }
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| 107 | }
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| 108 | if (k >= dstsiz)
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| 109 | return -1;
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| 110 | *pdst = '\0';
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| 111 | return 0;
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| 112 | }
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