src/journal/journal-qrcode.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2012 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <qrencode.h>
  23 #include <stdbool.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26
  27 #include "journal-qrcode.h"
  28
  29 #define WHITE_ON_BLACK "\033[40;37;1m"
  30 #define NORMAL "\033[0m"
  31
  32 static void print_border(FILE *output, unsigned width) {
  33         unsigned x, y;
  34
  35         /* Four rows of border */
  36         for (y = 0; y < 4; y += 2) {
  37                 fputs(WHITE_ON_BLACK, output);
  38
  39                 for (x = 0; x < 4 + width + 4; x++)
  40                         fputs("\342\226\210", output);
  41
  42                 fputs(NORMAL "\n", output);
  43         }
  44 }
  45
  46 int print_qr_code(
  47                 FILE *output,
  48                 const void *seed,
  49                 size_t seed_size,
  50                 uint64_t start,
  51                 uint64_t interval,
  52                 const char *hn,
  53                 sd_id128_t machine) {
  54
  55         FILE *f;
  56         char *url = NULL;
  57         size_t url_size = 0, i;
  58         QRcode* qr;
  59         unsigned x, y;
  60
  61         assert(seed);
  62         assert(seed_size > 0);
  63
  64         f = open_memstream(&url, &url_size);
  65         if (!f)
  66                 return -ENOMEM;
  67
  68         fputs("fss://", f);
  69
  70         for (i = 0; i < seed_size; i++) {
  71                 if (i > 0 && i % 3 == 0)
  72                         fputc('-', f);
  73                 fprintf(f, "%02x", ((uint8_t*) seed)[i]);
  74         }
  75
  76         fprintf(f, "/%"PRIx64"-%"PRIx64"?machine=" SD_ID128_FORMAT_STR,
  77                 start,
  78                 interval,
  79                 SD_ID128_FORMAT_VAL(machine));
  80
  81         if (hn)
  82                 fprintf(f, ";hostname=%s", hn);
  83
  84         if (ferror(f)) {
  85                 fclose(f);
  86                 free(url);
  87                 return -ENOMEM;
  88         }
  89
  90         fclose(f);
  91
  92         qr = QRcode_encodeString(url, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
  93         free(url);
  94
  95         if (!qr)
  96                 return -ENOMEM;
  97
  98         print_border(output, qr->width);
  99
 100         for (y = 0; y < (unsigned) qr->width; y += 2) {
 101                 const uint8_t *row1, *row2;
 102
 103                 row1 = qr->data + qr->width * y;
 104                 row2 = row1 + qr->width;
 105
 106                 fputs(WHITE_ON_BLACK, output);
 107                 for (x = 0; x < 4; x++)
 108                         fputs("\342\226\210", output);
 109
 110                 for (x = 0; x < (unsigned) qr->width; x ++) {
 111                         bool a, b;
 112
 113                         a = row1[x] & 1;
 114                         b = (y+1) < (unsigned) qr->width ? (row2[x] & 1) : false;
 115
 116                         if (a && b)
 117                                 fputc(' ', output);
 118                         else if (a)
 119                                 fputs("\342\226\204", output);
 120                         else if (b)
 121                                 fputs("\342\226\200", output);
 122                         else
 123                                 fputs("\342\226\210", output);
 124                 }
 125
 126                 for (x = 0; x < 4; x++)
 127                         fputs("\342\226\210", output);
 128                 fputs(NORMAL "\n", output);
 129         }
 130
 131         print_border(output, qr->width);
 132
 133         QRcode_free(qr);
 134         return 0;
 135 }