src/journal/journal-qrcode.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <qrencode.h>
   5 #include <stdbool.h>
   6 #include <stdio.h>
   7 #include <stdio_ext.h>
   8 #include <stdlib.h>
   9
  10 #include "journal-qrcode.h"
  11 #include "macro.h"
  12
  13 #define WHITE_ON_BLACK "\033[40;37;1m"
  14 #define NORMAL "\033[0m"
  15
  16 static void print_border(FILE *output, unsigned width) {
  17         unsigned x, y;
  18
  19         /* Four rows of border */
  20         for (y = 0; y < 4; y += 2) {
  21                 fputs(WHITE_ON_BLACK, output);
  22
  23                 for (x = 0; x < 4 + width + 4; x++)
  24                         fputs("\342\226\210", output);
  25
  26                 fputs(NORMAL "\n", output);
  27         }
  28 }
  29
  30 int print_qr_code(
  31                 FILE *output,
  32                 const void *seed,
  33                 size_t seed_size,
  34                 uint64_t start,
  35                 uint64_t interval,
  36                 const char *hn,
  37                 sd_id128_t machine) {
  38
  39         FILE *f;
  40         char *url = NULL;
  41         size_t url_size = 0, i;
  42         QRcode* qr;
  43         unsigned x, y;
  44
  45         assert(seed);
  46         assert(seed_size > 0);
  47
  48         f = open_memstream(&url, &url_size);
  49         if (!f)
  50                 return -ENOMEM;
  51
  52         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
  53
  54         fputs("fss://", f);
  55
  56         for (i = 0; i < seed_size; i++) {
  57                 if (i > 0 && i % 3 == 0)
  58                         fputc('-', f);
  59                 fprintf(f, "%02x", ((uint8_t*) seed)[i]);
  60         }
  61
  62         fprintf(f, "/%"PRIx64"-%"PRIx64"?machine=" SD_ID128_FORMAT_STR,
  63                 start,
  64                 interval,
  65                 SD_ID128_FORMAT_VAL(machine));
  66
  67         if (hn)
  68                 fprintf(f, ";hostname=%s", hn);
  69
  70         if (ferror(f)) {
  71                 fclose(f);
  72                 free(url);
  73                 return -ENOMEM;
  74         }
  75
  76         fclose(f);
  77
  78         qr = QRcode_encodeString(url, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
  79         free(url);
  80
  81         if (!qr)
  82                 return -ENOMEM;
  83
  84         print_border(output, qr->width);
  85
  86         for (y = 0; y < (unsigned) qr->width; y += 2) {
  87                 const uint8_t *row1, *row2;
  88
  89                 row1 = qr->data + qr->width * y;
  90                 row2 = row1 + qr->width;
  91
  92                 fputs(WHITE_ON_BLACK, output);
  93                 for (x = 0; x < 4; x++)
  94                         fputs("\342\226\210", output);
  95
  96                 for (x = 0; x < (unsigned) qr->width; x ++) {
  97                         bool a, b;
  98
  99                         a = row1[x] & 1;
 100                         b = (y+1) < (unsigned) qr->width ? (row2[x] & 1) : false;
 101
 102                         if (a && b)
 103                                 fputc(' ', output);
 104                         else if (a)
 105                                 fputs("\342\226\204", output);
 106                         else if (b)
 107                                 fputs("\342\226\200", output);
 108                         else
 109                                 fputs("\342\226\210", output);
 110                 }
 111
 112                 for (x = 0; x < 4; x++)
 113                         fputs("\342\226\210", output);
 114                 fputs(NORMAL "\n", output);
 115         }
 116
 117         print_border(output, qr->width);
 118
 119         QRcode_free(qr);
 120         return 0;
 121 }