mirror of
https://github.com/DarkFlippers/unleashed-firmware
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72 lines
2.4 KiB
C
72 lines
2.4 KiB
C
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/*
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* Base64 encoding/decoding (RFC1341)
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* Copyright (c) 2005, Jouni Malinen <j@w1.fi>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Alternatively, this software may be distributed under the terms of BSD
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* license.
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*
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*/
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#include "base64.h"
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#include <string.h>
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static const uint8_t dtable[] = {0x3e, 0x80, 0x80, 0x80, 0x3f, 0x34, 0x35, 0x36, 0x37, 0x38,
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0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x80, 0x80, 0x80, 0x0, 0x80,
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0x80, 0x80, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
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0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf, 0x10, 0x11,
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0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
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0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29,
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0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33};
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// "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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static uint8_t get_dtable_value(uint8_t index) {
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return (index < 43 || index > 122) ? 0x80 : dtable[index - 43];
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}
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uint8_t* base64_decode(const uint8_t* src, size_t len, size_t* out_len, size_t* out_size) {
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uint8_t *out;
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uint8_t *pos;
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uint8_t in[4];
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uint8_t block[4];
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uint8_t tmp;
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size_t i;
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size_t count;
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size_t olen;
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count = 0;
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for(i = 0; i < len; i++) {
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if(get_dtable_value(src[i]) != 0x80) count++;
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}
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if(count == 0 || count % 4) return NULL;
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olen = count / 4 * 3;
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pos = out = malloc(olen);
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*out_size = olen;
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if(out == NULL) return NULL;
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count = 0;
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for(i = 0; i < len; i++) {
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tmp = get_dtable_value(src[i]);
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if(tmp == 0x80) continue;
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in[count] = src[i];
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block[count] = tmp;
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count++;
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if(count == 4) {
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*pos++ = (block[0] << 2) | (block[1] >> 4);
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*pos++ = (block[1] << 4) | (block[2] >> 2);
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*pos++ = (block[2] << 6) | block[3];
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count = 0;
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}
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}
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if(pos > out) {
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if(in[2] == '=')
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pos -= 2;
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else if(in[3] == '=')
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pos--;
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}
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*out_len = pos - out;
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return out;
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}
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