dtrust-tool: Refactor PIN entry logic

src/tools/dtrust-tool.c

@@ -63,21 +63,12 @@ static int opt_check = 0;
 static int opt_unlock = 0;
 
 int
-verify_pace(sc_card_t *card, int ref, const char *pin_label)
+verify_pace(sc_card_t *card, int ref, const char *pin)
 {
  int r;
- char *pin = NULL;
- size_t pin_len = 0;
  struct establish_pace_channel_input pace_input;
  struct establish_pace_channel_output pace_output;
 
- printf("Enter %s:", pin_label);
- r = util_getpass(&pin, &pin_len, stdin);
- if (r < 0 || pin == NULL) {
- printf("Unable to get PIN.\n");
- return -1;
- }
-
  memset(&pace_input, 0, sizeof pace_input);
  memset(&pace_output, 0, sizeof pace_output);
 
@@ -87,21 +78,69 @@ verify_pace(sc_card_t *card, int ref, const char *pin_label)
 
  r = perform_pace(card, pace_input, &pace_output, EAC_TR_VERSION_2_02);
 
- sc_mem_clear(pin, pin_len);
- free(pin);
-
  free(pace_output.ef_cardaccess);
  free(pace_output.recent_car);
  free(pace_output.previous_car);
  free(pace_output.id_icc);
  free(pace_output.id_pcd);
 
- if (r) {
- printf("Error verifying CAN.\n");
+ return r;
+}
+
+int
+get_pin(char **pin, const char *label, unsigned char check)
+{
+ int r;
+ char *pin2 = NULL;
+ size_t len1 = 0;
+ size_t len2 = 0;
+
+ r = -1;
+
+ if (pin == NULL)
  return -1;
+
+ *pin = NULL;
+
+ printf("Enter %s:", label);
+ r = util_getpass(pin, &len1, stdin);
+ if (r < 0 || *pin == NULL) {
+ fprintf(stderr, "Unable to get PIN");
+ goto fail;
+ }
+
+ if (!check)
+ return 0;
+
+ printf("Enter %s again:", label);
+ r = util_getpass(&pin2, &len2, stdin);
+ if (r < 0 || pin2 == NULL) {
+ fprintf(stderr, "Unable to get PIN");
+ goto fail;
  }
 
- return 0;
+ r = strcmp(*pin, pin2);
+ if (r)
+ fprintf(stderr, "PINs doesn't match.\n");
+
+ /* Free repeated PIN in any case. */
+ if (pin2 != NULL) {
+ sc_mem_clear(pin2, len2);
+ free(pin2);
+ }
+
+ if (r == 0)
+ return 0;
+
+fail:
+ /* Free PIN only in case of an error. */
+ if (*pin != NULL) {
+ sc_mem_clear(*pin, len1);
+ free(*pin);
+ *pin = NULL;
+ }
+
+ return -1;
 }
 
 void
@@ -180,11 +219,7 @@ unlock_transport_protection(sc_card_t *card)
  struct sc_pin_cmd_data data;
  int r;
  char *tpin = NULL;
- char *qespin1 = NULL;
- char *qespin2 = NULL;
- size_t tpin_len = 0;
- size_t qespin1_len = 0;
- size_t qespin2_len = 0;
+ char *qespin = NULL;
  int tries_left;
 
  memset(&data, 0, sizeof(data));
@@ -202,35 +237,18 @@ unlock_transport_protection(sc_card_t *card)
  data.pin2.prompt = "Enter Signature PIN";
  data.flags |= SC_PIN_CMD_USE_PINPAD;
  } else {
- printf("Enter Transport PIN:");
- r = util_getpass(&tpin, &tpin_len, stdin);
- if (r < 0 || tpin == NULL) {
- fprintf(stderr, "Unable to get PIN");
- return;
- }
+ r = get_pin(&tpin, "Transport PIN", 0);
+ if (r < 0)
+ goto fail;
 
- printf("Enter new Signature PIN:");
- r = util_getpass(&qespin1, &qespin1_len, stdin);
- if (r < 0 || qespin1 == NULL) {
- fprintf(stderr, "Unable to get PIN");
- goto fail_qespin1;
- }
+ r = get_pin(&qespin, "new Signature PIN", 1);
+ if (r < 0)
+ goto fail;
 
- printf("Enter new Signature PIN again:");
- r = util_getpass(&qespin2, &qespin1_len, stdin);
- if (r < 0 || qespin2 == NULL) {
- fprintf(stderr, "Unable to get PIN");
- goto fail_qespin2;
- }
-
- if (strcmp(qespin1, qespin2)) {
- fprintf(stderr, "New signature PINs doesn't match.\n");
- goto fail_qespin2;
- }
  data.pin1.data = (u8 *)tpin;
  data.pin1.len = strlen(tpin);
- data.pin2.data = (u8 *)qespin1;
- data.pin2.len = strlen(qespin1);
+ data.pin2.data = (u8 *)qespin;
+ data.pin2.len = strlen(qespin);
  }
 
  r = sc_pin_cmd(card, &data, &tries_left);
@@ -242,20 +260,14 @@ unlock_transport_protection(sc_card_t *card)
  else
  printf("Can't change pin: %s\n", sc_strerror(r));
 
- if (qespin2 != NULL) {
- sc_mem_clear(qespin2, qespin2_len);
- free(qespin2);
+fail:
+ if (qespin != NULL) {
+ sc_mem_clear(qespin, strlen(qespin));
+ free(qespin);
  }
 
-fail_qespin2:
- if (qespin1 != NULL) {
- sc_mem_clear(qespin1, qespin1_len);
- free(qespin1);
- }
-
-fail_qespin1:
  if (tpin != NULL) {
- sc_mem_clear(tpin, tpin_len);
+ sc_mem_clear(tpin, strlen(tpin));
  free(tpin);
  }
 }
@@ -267,6 +279,7 @@ main(int argc, char *argv[])
  sc_context_param_t ctx_param;
  sc_card_t *card = NULL;
  sc_context_t *ctx = NULL;
+ char *can = NULL;
  sc_path_t path;
 
  while (1) {
@@ -330,9 +343,15 @@ main(int argc, char *argv[])
  card->type == SC_CARD_TYPE_DTRUST_V5_4_MULTI) {
  /* D-Trust Card 5 requires PACE authentication with CAN */
  if (opt_status || opt_check) {
- r = verify_pace(card, PACE_CAN, "CAN");
- if (r)
+ r = get_pin(&can, "CAN", 0);
+ if (r < 0)
  goto out;
+
+ r = verify_pace(card, PACE_CAN, can);
+ if (r) {
+ printf("Error verifying CAN.\n");
+ goto out;
+ }
  }
  }
 
@@ -417,6 +436,11 @@ main(int argc, char *argv[])
  }
 
 out:
+ if (can != NULL) {
+ sc_mem_clear(can, strlen(can));
+ free(can);
+ }
+
  if (card) {
  sc_unlock(card);
  sc_disconnect_card(card);