1 files changed, 102 insertions, 0 deletions
diff --git a/ready_se/google/keymint/KM200/Applet/src/com/android/javacard/keymaster/KMTag.java b/ready_se/google/keymint/KM200/Applet/src/com/android/javacard/keymaster/KMTag.java
new file mode 100644
index 0000000..3033a70
--- /dev/null
+++ b/ready_se/google/keymint/KM200/Applet/src/com/android/javacard/keymaster/KMTag.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright(C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.javacard.keymaster;
+
+import com.android.javacard.seprovider.KMException;
+import javacard.framework.Util;
+
+/**
+ * This class represents a tag as defined by keymaster hal specifications. It is composed of key
+ * value pair. The key consists of short tag type e.g. KMType.ENUM and short tag key e.g.
+ * KMType.ALGORITHM. The key is encoded as uint CBOR type with 4 bytes. This is followed by value
+ * which can be any CBOR type based on key. struct{byte tag=KMType.TAG_TYPE, short length, value)
+ * where value is subtype of KMTag i.e. struct{short tagType=one of tag types declared in KMType ,
+ * short tagKey=one of the tag keys declared in KMType, value} where value is one of the sub-types
+ * of KMType.
+ */
+public class KMTag extends KMType {
+
+  public static short getTagType(short ptr) {
+    return Util.getShort(heap, (short) (ptr + TLV_HEADER_SIZE));
+  }
+
+  public static short getKey(short ptr) {
+    return Util.getShort(heap, (short) (ptr + TLV_HEADER_SIZE + 2));
+  }
+
+  public static void assertPresence(short params, short tagType, short tagKey, short error) {
+    if (!isPresent(params, tagType, tagKey)) {
+      KMException.throwIt(error);
+    }
+  }
+
+  public static void assertAbsence(short params, short tagType, short tagKey, short error) {
+    if (isPresent(params, tagType, tagKey)) {
+      KMException.throwIt(error);
+    }
+  }
+
+  public static boolean isPresent(short params, short tagType, short tagKey) {
+    short tag = KMKeyParameters.findTag(tagType, tagKey, params);
+    return tag != KMType.INVALID_VALUE;
+  }
+
+  public static boolean isEqual(short params, short tagType, short tagKey, short value) {
+    switch (tagType) {
+      case KMType.ENUM_TAG:
+        return KMEnumTag.getValue(tagKey, params) == value;
+      case KMType.UINT_TAG:
+      case KMType.DATE_TAG:
+      case KMType.ULONG_TAG:
+        return KMIntegerTag.isEqual(params, tagType, tagKey, value);
+      case KMType.ENUM_ARRAY_TAG:
+        return KMEnumArrayTag.contains(tagKey, value, params);
+      case KMType.UINT_ARRAY_TAG:
+      case KMType.ULONG_ARRAY_TAG:
+        return KMIntegerArrayTag.contains(tagKey, value, params);
+    }
+    return false;
+  }
+
+  public static void assertTrue(boolean condition, short error) {
+    if (!condition) {
+      KMException.throwIt(error);
+    }
+  }
+
+  public static boolean isValidPublicExponent(short params) {
+    short pubExp = KMKeyParameters.findTag(KMType.ULONG_TAG, KMType.RSA_PUBLIC_EXPONENT, params);
+    if (pubExp == KMType.INVALID_VALUE) {
+      return false;
+    }
+    pubExp = KMIntegerTag.cast(pubExp).getValue();
+    if (!(KMInteger.cast(pubExp).getShort() == 0x01
+        && KMInteger.cast(pubExp).getSignificantShort() == 0x01)) {
+      return false;
+    }
+    return true;
+  }
+
+  public static boolean isValidKeySize(short params) {
+    short keysize = KMKeyParameters.findTag(KMType.UINT_TAG, KMType.KEYSIZE, params);
+    if (keysize == KMType.INVALID_VALUE) {
+      return false;
+    }
+    short alg = KMEnumTag.getValue(KMType.ALGORITHM, params);
+    return KMIntegerTag.cast(keysize).isValidKeySize((byte) alg);
+  }
+}