src/journal/journal-qrcode.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2012 Lennart Poettering
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  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 #include "macro.h"
  29
  30 #define WHITE_ON_BLACK "\033[40;37;1m"
  31 #define NORMAL "\033[0m"
  32
  33 static void print_border(FILE *output, unsigned width) {
  34         unsigned x, y;
  35
  36         /* Four rows of border */
  37         for (y = 0; y < 4; y += 2) {
  38                 fputs(WHITE_ON_BLACK, output);
  39
  40                 for (x = 0; x < 4 + width + 4; x++)
  41                         fputs("\342\226\210", output);
  42
  43                 fputs(NORMAL "\n", output);
  44         }
  45 }
  46
  47 int print_qr_code(
  48                 FILE *output,
  49                 const void *seed,
  50                 size_t seed_size,
  51                 uint64_t start,
  52                 uint64_t interval,
  53                 const char *hn,
  54                 sd_id128_t machine) {
  55
  56         FILE *f;
  57         char *url = NULL;
  58         size_t url_size = 0, i;
  59         QRcode* qr;
  60         unsigned x, y;
  61
  62         assert(seed);
  63         assert(seed_size > 0);
  64
  65         f = open_memstream(&url, &url_size);
  66         if (!f)
  67                 return -ENOMEM;
  68
  69         fputs_unlocked("fss://", f);
  70
  71         for (i = 0; i < seed_size; i++) {
  72                 if (i > 0 && i % 3 == 0)
  73                         fputc_unlocked('-', f);
  74                 fprintf(f, "%02x", ((uint8_t*) seed)[i]);
  75         }
  76
  77         fprintf(f, "/%"PRIx64"-%"PRIx64"?machine=" SD_ID128_FORMAT_STR,
  78                 start,
  79                 interval,
  80                 SD_ID128_FORMAT_VAL(machine));
  81
  82         if (hn)
  83                 fprintf(f, ";hostname=%s", hn);
  84
  85         if (ferror(f)) {
  86                 fclose(f);
  87                 free(url);
  88                 return -ENOMEM;
  89         }
  90
  91         fclose(f);
  92
  93         qr = QRcode_encodeString(url, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
  94         free(url);
  95
  96         if (!qr)
  97                 return -ENOMEM;
  98
  99         print_border(output, qr->width);
 100
 101         for (y = 0; y < (unsigned) qr->width; y += 2) {
 102                 const uint8_t *row1, *row2;
 103
 104                 row1 = qr->data + qr->width * y;
 105                 row2 = row1 + qr->width;
 106
 107                 fputs(WHITE_ON_BLACK, output);
 108                 for (x = 0; x < 4; x++)
 109                         fputs("\342\226\210", output);
 110
 111                 for (x = 0; x < (unsigned) qr->width; x ++) {
 112                         bool a, b;
 113
 114                         a = row1[x] & 1;
 115                         b = (y+1) < (unsigned) qr->width ? (row2[x] & 1) : false;
 116
 117                         if (a && b)
 118                                 fputc(' ', output);
 119                         else if (a)
 120                                 fputs("\342\226\204", output);
 121                         else if (b)
 122                                 fputs("\342\226\200", output);
 123                         else
 124                                 fputs("\342\226\210", output);
 125                 }
 126
 127                 for (x = 0; x < 4; x++)
 128                         fputs("\342\226\210", output);
 129                 fputs(NORMAL "\n", output);
 130         }
 131
 132         print_border(output, qr->width);
 133
 134         QRcode_free(qr);
 135         return 0;
 136 }