Wei Chang Shen / Motor_Embedded_3rd_emwin

Dependencies:   DMSupport DMemWin

embedded/Base64.cpp@0:08606a13a816, 2016-06-02 (annotated)

Committer:
destinyXfate
Date:
Thu Jun 02 05:04:57 2016 +0000
Revision:
0:08606a13a816
;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
destinyXfate 0:08606a13a816 1 /*
destinyXfate 0:08606a13a816 2 * Base64.cpp
destinyXfate 0:08606a13a816 3 *
destinyXfate 0:08606a13a816 4 * Created on: 2016/2/24
destinyXfate 0:08606a13a816 5 * Author: D10307009
destinyXfate 0:08606a13a816 6 */
destinyXfate 0:08606a13a816 7
destinyXfate 0:08606a13a816 8 //
destinyXfate 0:08606a13a816 9 // Base64 Encoding and Decoding
destinyXfate 0:08606a13a816 10 //
destinyXfate 0:08606a13a816 11 // @note Copyright © 2013 by Smartware Computing, all rights reserved.
destinyXfate 0:08606a13a816 12 // Individuals may use this application for evaluation or non-commercial
destinyXfate 0:08606a13a816 13 // purposes. Within this restriction, changes may be made to this application
destinyXfate 0:08606a13a816 14 // as long as this copyright notice is retained. The user shall make
destinyXfate 0:08606a13a816 15 // clear that their work is a derived work, and not the original.
destinyXfate 0:08606a13a816 16 // Users of this application and sources accept this application "as is" and
destinyXfate 0:08606a13a816 17 // shall hold harmless Smartware Computing, for any undesired results while
destinyXfate 0:08606a13a816 18 // using this application - whether real or imagined.
destinyXfate 0:08606a13a816 19 //
destinyXfate 0:08606a13a816 20 // author David Smart, Smartware Computing
destinyXfate 0:08606a13a816 21 //
destinyXfate 0:08606a13a816 22 #ifndef WIN32
destinyXfate 0:08606a13a816 23 #include "mbed.h"
destinyXfate 0:08606a13a816 24 #else
destinyXfate 0:08606a13a816 25 #include "windows.h"
destinyXfate 0:08606a13a816 26 typedef unsigned int uint32_t;
destinyXfate 0:08606a13a816 27 #endif
destinyXfate 0:08606a13a816 28 #include "Base64.h"
destinyXfate 0:08606a13a816 29 #include "FATFileSystem.h"
destinyXfate 0:08606a13a816 30
destinyXfate 0:08606a13a816 31 static const char encoding_table[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
destinyXfate 0:08606a13a816 32 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
destinyXfate 0:08606a13a816 33 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
destinyXfate 0:08606a13a816 34 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
destinyXfate 0:08606a13a816 35 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' };
destinyXfate 0:08606a13a816 36
destinyXfate 0:08606a13a816 37 static const int mod_table[] = { 0, 2, 1 };
destinyXfate 0:08606a13a816 38
destinyXfate 0:08606a13a816 39 Base64::Base64() {
destinyXfate 0:08606a13a816 40 decoding_table = NULL;
destinyXfate 0:08606a13a816 41 }
destinyXfate 0:08606a13a816 42
destinyXfate 0:08606a13a816 43 Base64::~Base64() {
destinyXfate 0:08606a13a816 44 if (decoding_table)
destinyXfate 0:08606a13a816 45 free(decoding_table);
destinyXfate 0:08606a13a816 46 }
destinyXfate 0:08606a13a816 47
destinyXfate 0:08606a13a816 48 char * Base64::Encode(const char *data, size_t input_length,
destinyXfate 0:08606a13a816 49 size_t *output_length) {
destinyXfate 0:08606a13a816 50 *output_length = 4 * ((input_length + 2) / 3);
destinyXfate 0:08606a13a816 51
destinyXfate 0:08606a13a816 52 char *encoded_data = (char *) malloc(*output_length + 1); // often used for text, so add room for NULL
destinyXfate 0:08606a13a816 53 if (encoded_data == NULL)
destinyXfate 0:08606a13a816 54 return NULL;
destinyXfate 0:08606a13a816 55
destinyXfate 0:08606a13a816 56 for (unsigned int i = 0, j = 0; i < input_length;) {
destinyXfate 0:08606a13a816 57
destinyXfate 0:08606a13a816 58 uint32_t octet_a = i < input_length ? data[i++] : 0;
destinyXfate 0:08606a13a816 59 uint32_t octet_b = i < input_length ? data[i++] : 0;
destinyXfate 0:08606a13a816 60 uint32_t octet_c = i < input_length ? data[i++] : 0;
destinyXfate 0:08606a13a816 61
destinyXfate 0:08606a13a816 62 uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
destinyXfate 0:08606a13a816 63
destinyXfate 0:08606a13a816 64 encoded_data[j++] = encoding_table[(triple >> 3 * 6) & 0x3F];
destinyXfate 0:08606a13a816 65 encoded_data[j++] = encoding_table[(triple >> 2 * 6) & 0x3F];
destinyXfate 0:08606a13a816 66 encoded_data[j++] = encoding_table[(triple >> 1 * 6) & 0x3F];
destinyXfate 0:08606a13a816 67 encoded_data[j++] = encoding_table[(triple >> 0 * 6) & 0x3F];
destinyXfate 0:08606a13a816 68 }
destinyXfate 0:08606a13a816 69
destinyXfate 0:08606a13a816 70 for (int i = 0; i < mod_table[input_length % 3]; i++)
destinyXfate 0:08606a13a816 71 encoded_data[*output_length - 1 - i] = '=';
destinyXfate 0:08606a13a816 72
destinyXfate 0:08606a13a816 73 encoded_data[*output_length] = '\0'; // as a courtesy to text users
destinyXfate 0:08606a13a816 74 return encoded_data;
destinyXfate 0:08606a13a816 75 }
destinyXfate 0:08606a13a816 76
destinyXfate 0:08606a13a816 77 int Base64::Encode(FILE *base, FILE *source) {
destinyXfate 0:08606a13a816 78
destinyXfate 0:08606a13a816 79 fseek(source, 0, SEEK_END);
destinyXfate 0:08606a13a816 80 size_t input_length = ftell(source);
destinyXfate 0:08606a13a816 81 fseek(source, 0, SEEK_SET);
destinyXfate 0:08606a13a816 82 size_t output_length = 4 * ((input_length + 2) / 3);
destinyXfate 0:08606a13a816 83
destinyXfate 0:08606a13a816 84 char buff_in[3];
destinyXfate 0:08606a13a816 85 char buff_out[4];
destinyXfate 0:08606a13a816 86 memset(buff_in, 0, 3);
destinyXfate 0:08606a13a816 87
destinyXfate 0:08606a13a816 88 size_t ret;
destinyXfate 0:08606a13a816 89 while ((ret = fread(buff_in, 1, 3, source)) > 0) {
destinyXfate 0:08606a13a816 90
destinyXfate 0:08606a13a816 91 uint32_t triple = (buff_in[0] << 0x10) + (buff_in[1] << 0x08)
destinyXfate 0:08606a13a816 92 + buff_in[2];
destinyXfate 0:08606a13a816 93
destinyXfate 0:08606a13a816 94 buff_out[0] = encoding_table[(triple >> 3 * 6) & 0x3F];
destinyXfate 0:08606a13a816 95 buff_out[1] = encoding_table[(triple >> 2 * 6) & 0x3F];
destinyXfate 0:08606a13a816 96 buff_out[2] = encoding_table[(triple >> 1 * 6) & 0x3F];
destinyXfate 0:08606a13a816 97 buff_out[3] = encoding_table[(triple >> 0 * 6) & 0x3F];
destinyXfate 0:08606a13a816 98
destinyXfate 0:08606a13a816 99 fwrite(buff_out, 1, 4, base);
destinyXfate 0:08606a13a816 100 memset(buff_in, 0, 3);
destinyXfate 0:08606a13a816 101 }
destinyXfate 0:08606a13a816 102
destinyXfate 0:08606a13a816 103 memcpy(buff_out, "===", 3);
destinyXfate 0:08606a13a816 104 long int mt = mod_table[input_length % 3];
destinyXfate 0:08606a13a816 105 fseek(base, mt*-1, SEEK_CUR);
destinyXfate 0:08606a13a816 106 fwrite(buff_out, 1, mt, base);
destinyXfate 0:08606a13a816 107
destinyXfate 0:08606a13a816 108 return 0;
destinyXfate 0:08606a13a816 109 }
destinyXfate 0:08606a13a816 110
destinyXfate 0:08606a13a816 111 char * Base64::Decode(const char *data, size_t input_length,
destinyXfate 0:08606a13a816 112 size_t *output_length) {
destinyXfate 0:08606a13a816 113 if (decoding_table == NULL)
destinyXfate 0:08606a13a816 114 build_decoding_table();
destinyXfate 0:08606a13a816 115
destinyXfate 0:08606a13a816 116 if (input_length % 4 != 0)
destinyXfate 0:08606a13a816 117 return NULL;
destinyXfate 0:08606a13a816 118
destinyXfate 0:08606a13a816 119 *output_length = input_length / 4 * 3;
destinyXfate 0:08606a13a816 120 if (data[input_length - 1] == '=')
destinyXfate 0:08606a13a816 121 (*output_length)--;
destinyXfate 0:08606a13a816 122 if (data[input_length - 2] == '=')
destinyXfate 0:08606a13a816 123 (*output_length)--;
destinyXfate 0:08606a13a816 124
destinyXfate 0:08606a13a816 125 char *decoded_data = (char *) malloc(*output_length + 1); // often used for text, so add room for NULL
destinyXfate 0:08606a13a816 126 if (decoded_data == NULL)
destinyXfate 0:08606a13a816 127 return NULL;
destinyXfate 0:08606a13a816 128
destinyXfate 0:08606a13a816 129 for (unsigned int i = 0, j = 0; i < input_length;) {
destinyXfate 0:08606a13a816 130
destinyXfate 0:08606a13a816 131 uint32_t sextet_a =
destinyXfate 0:08606a13a816 132 data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
destinyXfate 0:08606a13a816 133 uint32_t sextet_b =
destinyXfate 0:08606a13a816 134 data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
destinyXfate 0:08606a13a816 135 uint32_t sextet_c =
destinyXfate 0:08606a13a816 136 data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
destinyXfate 0:08606a13a816 137 uint32_t sextet_d =
destinyXfate 0:08606a13a816 138 data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
destinyXfate 0:08606a13a816 139
destinyXfate 0:08606a13a816 140 uint32_t triple = (sextet_a << 3 * 6) + (sextet_b << 2 * 6)
destinyXfate 0:08606a13a816 141 + (sextet_c << 1 * 6) + (sextet_d << 0 * 6);
destinyXfate 0:08606a13a816 142
destinyXfate 0:08606a13a816 143 if (j < *output_length)
destinyXfate 0:08606a13a816 144 decoded_data[j++] = (triple >> 2 * 8) & 0xFF;
destinyXfate 0:08606a13a816 145 if (j < *output_length)
destinyXfate 0:08606a13a816 146 decoded_data[j++] = (triple >> 1 * 8) & 0xFF;
destinyXfate 0:08606a13a816 147 if (j < *output_length)
destinyXfate 0:08606a13a816 148 decoded_data[j++] = (triple >> 0 * 8) & 0xFF;
destinyXfate 0:08606a13a816 149 }
destinyXfate 0:08606a13a816 150 decoded_data[*output_length] = '\0'; // as a courtesy to text users
destinyXfate 0:08606a13a816 151 return decoded_data;
destinyXfate 0:08606a13a816 152 }
destinyXfate 0:08606a13a816 153
destinyXfate 0:08606a13a816 154 void Base64::build_decoding_table() {
destinyXfate 0:08606a13a816 155 decoding_table = (char *) malloc(256);
destinyXfate 0:08606a13a816 156
destinyXfate 0:08606a13a816 157 for (int i = 0; i < 64; i++)
destinyXfate 0:08606a13a816 158 decoding_table[(unsigned char) encoding_table[i]] = i;
destinyXfate 0:08606a13a816 159 }
destinyXfate 0:08606a13a816 160
destinyXfate 0:08606a13a816 161