Add: Emv first part of commands

[proxmark3-svn] / client / emv / dol.c

diff --git a/client/emv/dol.c b/client/emv/dol.c
new file mode 100644 (file)
index 0000000..0fc1c49
--- /dev/null
+++ b/client/emv/dol.c
@@ -0,0 +1,135 @@
+/*
+ * libopenemv - a library to work with EMV family of smart cards
+ * Copyright (C) 2015 Dmitry Eremin-Solenikov
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "emv/dol.h"
+#include "emv/tlv.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+static size_t dol_calculate_len(const struct tlv *tlv, size_t data_len)
+{
+       if (!tlv)
+               return 0;
+
+       const unsigned char *buf = tlv->value;
+       size_t left = tlv->len;
+       size_t count = 0;
+
+       while (left) {
+               struct tlv tlv;
+               if (!tlv_parse_tl(&buf, &left, &tlv))
+                       return 0;
+
+               count += tlv.len;
+
+               /* Last tag can be of variable length */
+               if (tlv.len == 0 && left == 0)
+                       count = data_len;
+       }
+
+       return count;
+}
+
+struct tlv *dol_process(const struct tlv *tlv, const struct tlvdb *tlvdb, tlv_tag_t tag)
+{
+       size_t res_len;
+       if (!tlv || !(res_len = dol_calculate_len(tlv, 0))) {
+               struct tlv *res_tlv = malloc(sizeof(*res_tlv));
+
+               res_tlv->tag = tag;
+               res_tlv->len = 0;
+               res_tlv->value = NULL;
+
+               return res_tlv;
+       }
+
+       struct tlv *res_tlv = malloc(sizeof(*res_tlv) + res_len);
+       if (!res_tlv)
+               return NULL;
+
+       const unsigned char *buf = tlv->value;
+       size_t left = tlv->len;
+       unsigned char *res = (unsigned char *)(res_tlv + 1);
+       size_t pos = 0;
+
+       while (left) {
+               struct tlv cur_tlv;
+               if (!tlv_parse_tl(&buf, &left, &cur_tlv) || pos + cur_tlv.len > res_len) {
+                       free(res_tlv);
+
+                       return NULL;
+               }
+
+               const struct tlv *tag_tlv = tlvdb_get(tlvdb, cur_tlv.tag, NULL);
+               if (!tag_tlv) {
+                       memset(res + pos, 0, cur_tlv.len);
+               } else if (tag_tlv->len > cur_tlv.len) {
+                       memcpy(res + pos, tag_tlv->value, cur_tlv.len);
+               } else {
+                       // FIXME: cn data should be padded with 0xFF !!!
+                       memcpy(res + pos, tag_tlv->value, tag_tlv->len);
+                       memset(res + pos + tag_tlv->len, 0, cur_tlv.len - tag_tlv->len);
+               }
+               pos += cur_tlv.len;
+       }
+
+       res_tlv->tag = tag;
+       res_tlv->len = res_len;
+       res_tlv->value = res;
+
+       return res_tlv;
+}
+
+struct tlvdb *dol_parse(const struct tlv *tlv, const unsigned char *data, size_t data_len)
+{
+       if (!tlv)
+               return NULL;
+
+       const unsigned char *buf = tlv->value;
+       size_t left = tlv->len;
+       size_t res_len = dol_calculate_len(tlv, data_len);
+       size_t pos = 0;
+       struct tlvdb *db = NULL;
+
+       if (res_len != data_len)
+               return NULL;
+
+       while (left) {
+               struct tlv cur_tlv;
+               if (!tlv_parse_tl(&buf, &left, &cur_tlv) || pos + cur_tlv.len > res_len) {
+                       tlvdb_free(db);
+                       return NULL;
+               }
+
+               /* Last tag can be of variable length */
+               if (cur_tlv.len == 0 && left == 0)
+                       cur_tlv.len = res_len - pos;
+
+               struct tlvdb *tag_db = tlvdb_fixed(cur_tlv.tag, cur_tlv.len, data + pos);
+               if (!db)
+                       db = tag_db;
+               else
+                       tlvdb_add(db, tag_db);
+
+               pos += cur_tlv.len;
+       }
+
+       return db;
+}