From 4173b5448cf4c3b945fe8dd40d5186870b787f71 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Sun, 27 Jan 2013 22:45:10 +0000
Subject: filling unused key slots with 0xff reading infinite number of bytes
 after update

git-svn-id: https://svn.spreadspace.org/avr/trunk@76 aa12f405-d877-488e-9caf-2d797e2a1cc7
---
 usb-i2c-sl018/update-keys.c | 60 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 49 insertions(+), 11 deletions(-)

(limited to 'usb-i2c-sl018')

diff --git a/usb-i2c-sl018/update-keys.c b/usb-i2c-sl018/update-keys.c
index dc082ed..5b80c97 100644
--- a/usb-i2c-sl018/update-keys.c
+++ b/usb-i2c-sl018/update-keys.c
@@ -20,24 +20,46 @@
  *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <stdint.h>
 #include <ctype.h>
 #include <stdio.h>
 
-#define MAX_KEY_LEN 7
+#define KEY_LEN_MAX 7
+#define MAX_KEYS 128
 
-char generate_csum(char* key)
+char generate_csum(char* data)
 {
-  return 0xFF;
+  uint16_t sum1 = 0xf, sum2 = 0xf, len = KEY_LEN_MAX;
+  do { sum2 += ( sum1 += *data++ ); } while (--len);
+  return sum2<<4 | sum1;
 }
 
 int main(int argc, char* argv[])
 {
+  if(argc<2) {
+    fprintf(stderr, "Usage: update-keys <device>\n");
+    return -1;
+  }
+  
+  FILE* dev;
+  dev = fopen(argv[1], "r+");
+  if(!dev) {
+    fprintf(stderr, "fopen failed!\n");
+    return -2;
+  }
+
+  fprintf(dev, "e");
+
   char* line = NULL;
   size_t len = 0;
+  int line_num = 0;
+  uint8_t key[KEY_LEN_MAX+1];
+  int key_num = 0;
 
   for(;;) {
     ssize_t ret = getline(&line, &len, stdin);
-    if(ret <= 0) return 0;
+    if(ret <= 0) break;
+    line_num++;
 
     int i;
     for(i=0; i<len; ++i) {
@@ -46,24 +68,40 @@ int main(int argc, char* argv[])
         break;
       }
     }
-    if(i & 1 || i == 0 || i > MAX_KEY_LEN*2) {
-      fprintf(stderr, "ignoring invalid key (odd number of digits or empty string or too long): %s\n", line);
+    if(i & 1 || i == 0 || i > KEY_LEN_MAX*2) {
+      fprintf(stderr, "ignoring invalid key (odd number of digits or empty string or too long) at line %d\n", line_num);
       continue;
     }
-    char key[MAX_KEY_LEN+1];
+    uint8_t tmp[3];
     int j;
-    char tmp[3];
     tmp[2] = 0;
     for(j = 0; j<(i/2); ++j) {
       tmp[0] = line[j*2];
       tmp[1] = line[j*2 + 1];
       key[j] = (char)strtoul(tmp, NULL, 16);
     }
-    for(j=i/2; j < MAX_KEY_LEN; ++j) {
+    for(j=i/2; j < KEY_LEN_MAX; ++j) {
       key[j] = 0;
     }
-    key[MAX_KEY_LEN] = generate_csum(key);
-    ret = fwrite(key, MAX_KEY_LEN+1, 1, stdout);
+    key[KEY_LEN_MAX] = generate_csum(key);
+    fwrite(key, KEY_LEN_MAX+1, 1, dev);
+    key_num++;
+    if(key_num > MAX_KEYS) {
+      fprintf(stderr, "reached maximum number of key slots (%d), will ignore remaining keys\n", MAX_KEYS);
+      break;
+    }
+  }
+
+  printf("read %d keys from STDIN\n", key_num);
+  
+  int i;
+  for(i=0; i<=KEY_LEN_MAX; ++i) key[i] = 0xFF;
+  for(i=key_num; i < MAX_KEYS; ++i)
+    fwrite(key, KEY_LEN_MAX+1, 1, dev);
+
+  char tmp;
+  while(fread(&tmp, 1, 1, dev)) {
+    fwrite(&tmp, 1, 1, dev);
   }
 
   return 0;
-- 
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