CardOS: Try forcing max_send_size for PSO:DEC

Fixes #1208
Fixes #1118
Fixes #1005
Fixes #802

src/libopensc/card-cardos.c

@@ -977,6 +977,32 @@ cardos_compute_signature(sc_card_t *card, const u8 *data, size_t datalen,
  LOG_FUNC_RETURN(ctx, SC_ERROR_INTERNAL);
 }
 
+static int
+cardos_decipher(struct sc_card *card,
+ const u8 * crgram, size_t crgram_len,
+ u8 * out, size_t outlen)
+{
+ int r;
+ size_t card_max_send_size = card->max_send_size;
+ size_t reader_max_send_size = card->reader->max_send_size;
+
+ if (sc_get_max_send_size(card) < crgram_len + 1) {
+ /* CardOS doesn't support chaining for PSO:DEC, so we just _hope_
+ * that both, the reader and the card are able to send enough data.
+ * (data is prefixed with 1 byte padding content indicator) */
+ card->max_send_size = crgram_len + 1;
+ card->reader->max_send_size = crgram_len + 1;
+ }
+
+ r = iso_ops->decipher(card, crgram, crgram_len, out, outlen);
+
+ /* reset whatever we've modified above */
+ card->max_send_size = card_max_send_size;
+ card->reader->max_send_size = reader_max_send_size;
+
+ return r;
+}
+
 static int
 cardos_lifecycle_get(sc_card_t *card, int *mode)
 {
@@ -1280,6 +1306,7 @@ static struct sc_card_driver * sc_get_driver(void)
  cardos_ops.set_security_env = cardos_set_security_env;
  cardos_ops.restore_security_env = cardos_restore_security_env;
  cardos_ops.compute_signature = cardos_compute_signature;
+ cardos_ops.decipher = cardos_decipher;
 
  cardos_ops.list_files = cardos_list_files;
  cardos_ops.check_sw = cardos_check_sw;