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Diffstat (limited to '')
| -rw-r--r-- | cpukit/base64/base64-decode.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/cpukit/base64/base64-decode.c b/cpukit/base64/base64-decode.c new file mode 100644 index 0000000000..5739266528 --- /dev/null +++ b/cpukit/base64/base64-decode.c @@ -0,0 +1,165 @@ +/* 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; +} |