/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSImplBase64
*
* @brief This source file contains the implementation of
* _Base64_Decode_initialize() and _Base64_Decode().
*/
/*
* Copyright (C) 2023 embedded brains GmbH & Co. KG
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <rtems/base64.h>
#define SPACE 253
#define PAD 254
#define INVALID 255
const uint8_t _Base64_Decoding[128] = {
['A'] = 0, ['B'] = 1, ['C'] = 2, ['D'] = 3,
['E'] = 4, ['F'] = 5, ['G'] = 6, ['H'] = 7,
['I'] = 8, ['J'] = 9, ['K'] = 10, ['L'] = 11,
['M'] = 12, ['N'] = 13, ['O'] = 14, ['P'] = 15,
['Q'] = 16, ['R'] = 17, ['S'] = 18, ['T'] = 19,
['U'] = 20, ['V'] = 21, ['W'] = 22, ['X'] = 23,
['Y'] = 24, ['Z'] = 25, ['a'] = 26, ['b'] = 27,
['c'] = 28, ['d'] = 29, ['e'] = 30, ['f'] = 31,
['g'] = 32, ['h'] = 33, ['i'] = 34, ['j'] = 35,
['k'] = 36, ['l'] = 37, ['m'] = 38, ['n'] = 39,
['o'] = 40, ['p'] = 41, ['q'] = 42, ['r'] = 43,
['s'] = 44, ['t'] = 45, ['u'] = 46, ['v'] = 47,
['w'] = 48, ['x'] = 49, ['y'] = 50, ['z'] = 51,
['0'] = 52, ['1'] = 53, ['2'] = 54, ['3'] = 55,
['4'] = 56, ['5'] = 57, ['6'] = 58, ['7'] = 59,
['8'] = 60, ['9'] = 61, ['+'] = 62, ['-'] = 62,
['/'] = 63, ['_'] = 63, ['='] = PAD, [' '] = SPACE,
['\t'] = SPACE, ['\n'] = SPACE, ['\v'] = SPACE, ['\f'] = SPACE,
['\r'] = SPACE, [0] = INVALID, [1] = INVALID, [2] = INVALID,
[3] = INVALID, [4] = INVALID, [5] = INVALID, [6] = INVALID,
[7] = INVALID, [8] = INVALID, [14] = INVALID, [15] = INVALID,
[16] = INVALID, [17] = INVALID, [18] = INVALID, [19] = INVALID,
[20] = INVALID, [21] = INVALID, [22] = INVALID, [23] = INVALID,
[24] = INVALID, [25] = INVALID, [26] = INVALID, [27] = INVALID,
[28] = INVALID, [29] = INVALID, [30] = INVALID, [31] = INVALID,
[33] = INVALID, [34] = INVALID, [35] = INVALID, [36] = INVALID,
[37] = INVALID, [38] = INVALID, [39] = INVALID, [40] = INVALID,
[41] = INVALID, [42] = INVALID, [44] = INVALID, [46] = INVALID,
[58] = INVALID, [59] = INVALID, [60] = INVALID, [62] = INVALID,
[63] = INVALID, [64] = INVALID, [91] = INVALID, [92] = INVALID,
[93] = INVALID, [94] = INVALID, [96] = INVALID, [123] = INVALID,
[124] = INVALID, [125] = INVALID, [126] = INVALID, [127] = INVALID};
void _Base64_Decode_initialize(Base64_Decode_control* self,
uint8_t* target,
size_t target_size) {
self->state = BASE64_DECODE_STATE_0;
self->target = target;
self->target_end = target + target_size;
}
Base64_Decode_status _Base64_Decode(Base64_Decode_control* self, char ch) {
uint8_t decoded_ch;
uint8_t next_ch;
uint8_t* target;
const uint8_t* target_end;
Base64_Decode_state next_state;
if ((unsigned char)ch >= 128) {
return BASE64_DECODE_INVALID_INPUT;
}
decoded_ch = _Base64_Decoding[(unsigned char)ch];
if (decoded_ch == SPACE) {
return BASE64_DECODE_SUCCESS;
}
target = self->target;
if (decoded_ch == PAD) {
self->target_end = target;
return BASE64_DECODE_SUCCESS;
}
if (decoded_ch == INVALID) {
return BASE64_DECODE_INVALID_INPUT;
}
target_end = self->target_end;
if (target == target_end) {
return BASE64_DECODE_OVERFLOW;
}
switch (self->state) {
case BASE64_DECODE_STATE_0:
*target = decoded_ch << 2;
next_state = BASE64_DECODE_STATE_1;
break;
case BASE64_DECODE_STATE_1:
*target |= decoded_ch >> 4;
next_ch = (decoded_ch & 0x0fU) << 4;
++target;
if (target != target_end) {
*target = next_ch;
} else if (next_ch != 0) {
return BASE64_DECODE_OVERFLOW;
}
next_state = BASE64_DECODE_STATE_2;
break;
case BASE64_DECODE_STATE_2:
*target |= decoded_ch >> 2;
next_ch = (decoded_ch & 0x03U) << 6;
++target;
if (target != target_end) {
*target = next_ch;
} else if (next_ch != 0) {
return BASE64_DECODE_OVERFLOW;
}
next_state = BASE64_DECODE_STATE_3;
break;
default: /* BASE64_DECODE_STATE_3 */
*target |= decoded_ch;
++target;
next_state = BASE64_DECODE_STATE_0;
break;
}
self->state = next_state;
self->target = target;
return BASE64_DECODE_SUCCESS;
}
