diff --git a/app/src/main/cpp/des.cpp b/app/src/main/cpp/des.cpp
index bc2b29b..0093dfc 100644
--- a/app/src/main/cpp/des.cpp
+++ b/app/src/main/cpp/des.cpp
@@ -177,9 +177,9 @@ bytes des_encrypt(bytes data, uint64_t key) {
         r.insert(r.end(), x.begin(), x.end());
         cbc = input;
     }
-    LOGI("des encrypt");
-    logBytes("  input", data);
-    logBytes("  output", r);
+    LOGI("des encrypt: %llx", key);
+    logBytes("  input %s", data);
+    logBytes("  output %s", r);
     return r;
 }
 
@@ -203,9 +203,9 @@ bytes tripledes_cbc_encrypt(bytes data, uint64_t key1, uint64_t key2, uint64_t k
         }
         cbc = input;
     }
-    LOGI("3des encrypt");
-    logBytes("  input", data);
-    logBytes("  output", r);
+    LOGI("3des encrypt: %llx %llx %llx", key1, key2, key3);
+    logBytes("  input %s", data);
+    logBytes("  output %s", r);
     return r;
 }
 
@@ -230,15 +230,15 @@ bytes tripledes_cbc_decrypt(bytes data, uint64_t key1, uint64_t key2, uint64_t k
         }
         cbc = before_transform;
     }
-    LOGI("3des decrypt");
-    logBytes("  input", data);
-    logBytes("  output", r);
+    LOGI("3des decrypt: %llx %llx %llx", key1, key2, key3);
+    logBytes("  input %s", data);
+    logBytes("  output %s", r);
     return r;
 }
 
-uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2, uint64_t key3) {
+uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2, uint64_t key3, bool pad) {
     bytes msg = data;
-    iso9797_pad(msg);
+    if (pad) iso9797_pad(msg);
 
     bytes mac = des_encrypt(msg, key1);
     mac.erase(mac.begin(), mac.end() - 8);
@@ -249,6 +249,10 @@ uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2, uint64_t key3) {
     return mac_value;
 }
 
+uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2) {
+    return iso9797_mac(data, key1, key2, key1, true);
+}
+
 bytes KDF(bytes keyseed, int32_t count) {
     bytes hash(20);
     bytes msg;
diff --git a/app/src/main/cpp/des.h b/app/src/main/cpp/des.h
index f850505..7cf9c26 100644
--- a/app/src/main/cpp/des.h
+++ b/app/src/main/cpp/des.h
@@ -158,12 +158,21 @@ uint64_t des(uint64_t input, uint64_t key, char mode);
 bytes des_encrypt(bytes data, uint64_t key);
 bytes tripledes_cbc_encrypt(bytes data, uint64_t key1, uint64_t key2, uint64_t key3);
 bytes tripledes_cbc_decrypt(bytes data, uint64_t key1, uint64_t key2, uint64_t key3);
-uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2, uint64_t key3);
+uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2, uint64_t key3, bool pad);
+uint64_t iso9797_mac(bytes data, uint64_t key1, uint64_t key2);
 inline void iso9797_pad(bytes& data) {
     bytes pad = {0x80, 0,0,0,0,0,0,0};
     size_t padsize = 8 - data.size() % 8;
     data.insert(data.end(), pad.begin(), pad.begin() + padsize);
 }
+inline void iso9797_unpad(bytes& data) {
+    auto end = data.rbegin();
+    while (*end != 0x80) {
+        end++;
+    }
+    end++;
+    data.erase(end.base(), data.rbegin().base());
+}
 
 bytes deriveKeyISO9797(bytes keyseed);
 bytes deriveKeyDesEDE(bytes keyseed);