PIV: move locking outside of piv_match_card_continued

This fixes an erroneous call of sc_unlock in piv_match_card_continued in
case of an error, which causes sc_unlock to be called more often than
sc_lock.

src/libopensc/card-piv.c

@@ -5304,11 +5304,15 @@ static int piv_match_card(sc_card_t *card)
  return 0; /* can not handle the card */
  }
 
+ r = sc_lock(card);
+ if (r < 0)
+ return 0;
  /* its one we know, or we can test for it in piv_init */
  r = piv_match_card_continued(card);
+ sc_unlock(card);
+
  if (r < 0 || !card->drv_data) {
  /* clean up what we left in card */
- sc_unlock(card);
  piv_finish(card);
  return 0; /* match failed */
  }
@@ -5327,14 +5331,6 @@ static int piv_match_card_continued(sc_card_t *card)
  sc_apdu_t apdu;
  u8 yubico_version_buf[3] = {0};
 
- r = sc_lock(card); /* hold until match or init is complete */
- if (r != SC_SUCCESS) {
- sc_debug(card->ctx, SC_LOG_DEBUG_VERBOSE, "sc_lock failed\n");
- piv_finish(card);
- card->type = saved_type;
- LOG_FUNC_RETURN(card->ctx, r);
- }
-
  /* piv_match_card may be called with card->type, set by opensc.conf */
  /* User provided card type must be one we know */
 
@@ -5694,7 +5690,6 @@ static int piv_match_card_continued(sc_card_t *card)
 err:
  sc_debug(card->ctx,SC_LOG_DEBUG_MATCH, "PIV_MATCH card->type:%d r2:%d CI:%08x r:%d\n", card->type, r2, priv->card_issues, r);
  /* don't match. Does not have a PIV applet. */
- sc_unlock(card);
  piv_finish(card);
  card->type = saved_type;
  LOG_FUNC_RETURN(card->ctx, r);
@@ -5710,6 +5705,9 @@ static int piv_init(sc_card_t *card)
 
  SC_FUNC_CALLED(card->ctx, SC_LOG_DEBUG_VERBOSE);
 
+ r = sc_lock(card); /* hold until match or init is complete */
+ LOG_TEST_RET(card->ctx, r, "sc_lock failed");
+
  /* piv_match_card_continued called from card match should have left card->drv_data */
  if (priv == NULL) {
  r = piv_match_card_continued(card);
@@ -5830,7 +5828,7 @@ static int piv_init(sc_card_t *card)
  piv_process_history(card);
 
  priv->pstate=PIV_STATE_NORMAL;
- sc_unlock(card) ; /* obtained in piv_match_card_continued */
+ sc_unlock(card);
  LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);
 }