From bf3fcc77fececdcf59ab3b5356d63530b2f8422c Mon Sep 17 00:00:00 2001
From: Klas Lindfors <klas@yubico.com>
Date: Fri, 8 May 2015 09:57:51 +0200
Subject: [PATCH] use a transation while sending and receiving data

---
 lib/ykpiv.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/lib/ykpiv.c b/lib/ykpiv.c
index 73a886f..0ea9517 100644
--- a/lib/ykpiv.c
+++ b/lib/ykpiv.c
@@ -230,8 +230,16 @@ ykpiv_rc ykpiv_transfer_data(ykpiv_state *state, const unsigned char *templ,
   const unsigned char *in_ptr = in_data;
   unsigned long max_out = *out_len;
   ykpiv_rc res;
+  long rc;
   *out_len = 0;
 
+  rc = SCardBeginTransaction(state->card);
+  if(rc != SCARD_S_SUCCESS) {
+    if(state->verbose) {
+      fprintf(stderr, "error: Failed to being pcsc transaction, rc=%08lx\n", rc);
+    }
+    return YKPIV_PCSC_ERROR;
+  }
   do {
     size_t this_size = 0xff;
     unsigned long recv_len = 0xff;
@@ -291,6 +299,13 @@ ykpiv_rc ykpiv_transfer_data(ykpiv_state *state, const unsigned char *templ,
     out_data += recv_len - 2;
     *out_len += recv_len - 2;
   }
+  rc = SCardEndTransaction(state->card, SCARD_LEAVE_CARD);
+  if(rc != SCARD_S_SUCCESS) {
+    if(state->verbose) {
+      fprintf(stderr, "error: Failed to end pcsc transaction, rc=%08lx\n", rc);
+    }
+    return YKPIV_PCSC_ERROR;
+  }
   return YKPIV_OK;
 }