src/journal/journal-qrcode.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2012 Lennart Poettering
   4 ***/
   5
   6 #include <errno.h>
   7 #include <qrencode.h>
   8 #include <stdbool.h>
   9 #include <stdio.h>
  10 #include <stdio_ext.h>
  11 #include <stdlib.h>
  12
  13 #include "journal-qrcode.h"
  14 #include "macro.h"
  15
  16 #define WHITE_ON_BLACK "\033[40;37;1m"
  17 #define NORMAL "\033[0m"
  18
  19 static void print_border(FILE *output, unsigned width) {
  20         unsigned x, y;
  21
  22         /* Four rows of border */
  23         for (y = 0; y < 4; y += 2) {
  24                 fputs(WHITE_ON_BLACK, output);
  25
  26                 for (x = 0; x < 4 + width + 4; x++)
  27                         fputs("\342\226\210", output);
  28
  29                 fputs(NORMAL "\n", output);
  30         }
  31 }
  32
  33 int print_qr_code(
  34                 FILE *output,
  35                 const void *seed,
  36                 size_t seed_size,
  37                 uint64_t start,
  38                 uint64_t interval,
  39                 const char *hn,
  40                 sd_id128_t machine) {
  41
  42         FILE *f;
  43         char *url = NULL;
  44         size_t url_size = 0, i;
  45         QRcode* qr;
  46         unsigned x, y;
  47
  48         assert(seed);
  49         assert(seed_size > 0);
  50
  51         f = open_memstream(&url, &url_size);
  52         if (!f)
  53                 return -ENOMEM;
  54
  55         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
  56
  57         fputs("fss://", f);
  58
  59         for (i = 0; i < seed_size; i++) {
  60                 if (i > 0 && i % 3 == 0)
  61                         fputc('-', f);
  62                 fprintf(f, "%02x", ((uint8_t*) seed)[i]);
  63         }
  64
  65         fprintf(f, "/%"PRIx64"-%"PRIx64"?machine=" SD_ID128_FORMAT_STR,
  66                 start,
  67                 interval,
  68                 SD_ID128_FORMAT_VAL(machine));
  69
  70         if (hn)
  71                 fprintf(f, ";hostname=%s", hn);
  72
  73         if (ferror(f)) {
  74                 fclose(f);
  75                 free(url);
  76                 return -ENOMEM;
  77         }
  78
  79         fclose(f);
  80
  81         qr = QRcode_encodeString(url, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
  82         free(url);
  83
  84         if (!qr)
  85                 return -ENOMEM;
  86
  87         print_border(output, qr->width);
  88
  89         for (y = 0; y < (unsigned) qr->width; y += 2) {
  90                 const uint8_t *row1, *row2;
  91
  92                 row1 = qr->data + qr->width * y;
  93                 row2 = row1 + qr->width;
  94
  95                 fputs(WHITE_ON_BLACK, output);
  96                 for (x = 0; x < 4; x++)
  97                         fputs("\342\226\210", output);
  98
  99                 for (x = 0; x < (unsigned) qr->width; x ++) {
 100                         bool a, b;
 101
 102                         a = row1[x] & 1;
 103                         b = (y+1) < (unsigned) qr->width ? (row2[x] & 1) : false;
 104
 105                         if (a && b)
 106                                 fputc(' ', output);
 107                         else if (a)
 108                                 fputs("\342\226\204", output);
 109                         else if (b)
 110                                 fputs("\342\226\200", output);
 111                         else
 112                                 fputs("\342\226\210", output);
 113                 }
 114
 115                 for (x = 0; x < 4; x++)
 116                         fputs("\342\226\210", output);
 117                 fputs(NORMAL "\n", output);
 118         }
 119
 120         print_border(output, qr->width);
 121
 122         QRcode_free(qr);
 123         return 0;
 124 }