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-rw-r--r--hw/usb/ccid-card-passthru.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/hw/usb/ccid-card-passthru.c b/hw/usb/ccid-card-passthru.c
index 275b8873dc..16d51c9295 100644
--- a/hw/usb/ccid-card-passthru.c
+++ b/hw/usb/ccid-card-passthru.c
@@ -138,6 +138,59 @@ static void ccid_card_vscard_handle_init(
ccid_card_vscard_send_init(card);
}
+static int check_atr(PassthruState *card, uint8_t *data, int len)
+{
+ int historical_length, opt_bytes;
+ int td_count = 0;
+ int td;
+
+ if (len < 2) {
+ return 0;
+ }
+ historical_length = data[1] & 0xf;
+ opt_bytes = 0;
+ if (data[0] != 0x3b && data[0] != 0x3f) {
+ DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
+ data[0]);
+ return 0;
+ }
+ td_count = 0;
+ td = data[1] >> 4;
+ while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
+ td_count++;
+ if (td & 0x1) {
+ opt_bytes++;
+ }
+ if (td & 0x2) {
+ opt_bytes++;
+ }
+ if (td & 0x4) {
+ opt_bytes++;
+ }
+ if (td & 0x8) {
+ opt_bytes++;
+ td = data[opt_bytes + 2] >> 4;
+ }
+ }
+ if (len < 2 + historical_length + opt_bytes) {
+ DPRINTF(card, D_WARN,
+ "atr too short: len %d, but historical_len %d, T1 0x%X\n",
+ len, historical_length, data[1]);
+ return 0;
+ }
+ if (len > 2 + historical_length + opt_bytes) {
+ DPRINTF(card, D_WARN,
+ "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
+ len, historical_length, opt_bytes, data[1]);
+ /* let it through */
+ }
+ DPRINTF(card, D_VERBOSE,
+ "atr passes check: %d total length, %d historical, %d optional\n",
+ len, historical_length, opt_bytes);
+
+ return 1;
+}
+
static void ccid_card_vscard_handle_message(PassthruState *card,
VSCMsgHeader *scr_msg_header)
{
@@ -152,6 +205,12 @@ static void ccid_card_vscard_handle_message(PassthruState *card,
VSC_GENERAL_ERROR);
break;
}
+ if (!check_atr(card, data, scr_msg_header->length)) {
+ error_report("ATR is inconsistent, ignoring");
+ ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
+ VSC_GENERAL_ERROR);
+ break;
+ }
memcpy(card->atr, data, scr_msg_header->length);
card->atr_length = scr_msg_header->length;
ccid_card_card_inserted(&card->base);