1 files changed, 70 insertions, 0 deletions

diff --git a/src/iso7816.c b/src/iso7816.c
new file mode 100644
index 0000000..e2ea281
--- /dev/null
+++ b/src/iso7816.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2018 Yubico AB. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+#include <string.h>
+#include "fido.h"
+
+iso7816_apdu_t *
+iso7816_new(uint8_t ins, uint8_t p1, uint16_t payload_len)
+{
+        iso7816_apdu_t  *apdu;
+        size_t           alloc_len;
+
+        alloc_len = sizeof(iso7816_apdu_t) + payload_len;
+
+        if ((apdu = calloc(1, alloc_len)) == NULL)
+                return (NULL);
+
+        apdu->alloc_len = alloc_len;
+        apdu->payload_len = payload_len;
+        apdu->payload_ptr = apdu->payload;
+        apdu->header.ins = ins;
+        apdu->header.p1 = p1;
+        apdu->header.lc2 = (payload_len >> 8) & 0xff;
+        apdu->header.lc3 = payload_len & 0xff;
+
+        return (apdu);
+}
+
+void
+iso7816_free(iso7816_apdu_t **apdu_p)
+{
+        iso7816_apdu_t *apdu;
+
+        if (apdu_p == NULL || (apdu = *apdu_p) == NULL)
+                return;
+
+        explicit_bzero(apdu, apdu->alloc_len);
+        free(apdu);
+
+        *apdu_p = NULL;
+}
+
+int
+iso7816_add(iso7816_apdu_t *apdu, const void *buf, size_t cnt)
+{
+        if (cnt > apdu->payload_len || cnt > UINT16_MAX)
+                return (-1);
+
+        memcpy(apdu->payload_ptr, buf, cnt);
+        apdu->payload_ptr += cnt;
+        apdu->payload_len -= (uint16_t)cnt;
+
+        return (0);
+}
+
+const unsigned char *
+iso7816_ptr(const iso7816_apdu_t *apdu)
+{
+        return ((const unsigned char *)&apdu->header);
+}
+
+size_t
+iso7816_len(const iso7816_apdu_t *apdu)
+{
+        return (apdu->alloc_len - sizeof(apdu->alloc_len) -
+            sizeof(apdu->payload_len) - sizeof(apdu->payload_ptr));
+}