+ while(param_getchar(Cmd, cmdp) != 0x00) {
+ switch(param_getchar(Cmd, cmdp)) {
+ case 'd':
+ case 'D':
+ // peek at length of the input string so we can
+ // figure out how many elements to malloc in "data"
+ bg=en=0;
+ if (param_getptr(Cmd, &bg, &en, cmdp+1)) {
+ errors = true;
+ break;
+ }
+ len = (en - bg + 1);
+
+ // check that user entered even number of characters
+ // for hex data string
+ if (len & 1) {
+ errors = true;
+ break;
+ }
+
+ // it's possible for user to accidentally enter "b" parameter
+ // more than once - we have to clean previous malloc
+ if (data)
+ free(data);
+ data = malloc(len >> 1);
+ if ( data == NULL ) {
+ PrintAndLog("Can't allocate memory. exiting");
+ errors = true;
+ break;
+ }
+
+ if (param_gethex(Cmd, cmdp+1, data, len)) {
+ errors = true;
+ break;
+ }
+
+ len >>= 1;
+ cmdp += 2;
+ break;
+ case 'o':
+ case 'O':
+ offset = param_get32ex(Cmd, cmdp+1, 4, 10);
+ cmdp += 2;
+ break;
+ case 'h':
+ case 'H':
+ errors = true;
+ break;
+ default:
+ PrintAndLog("Unknown parameter '%c'", param_getchar(Cmd, cmdp));
+ errors = true;
+ break;
+ }
+ if (errors) break;
+ }
+ //Validations
+ if (errors){
+ if (data)
+ free(data);
+ return usage_legic_write();
+ }
+