1 files changed, 38 insertions, 0 deletions
diff --git a/security-utils/src/main/java/com/yahoo/security/hpke/Constants.java b/security-utils/src/main/java/com/yahoo/security/hpke/Constants.java
new file mode 100644
index 00000000000..bfd810c10d2
--- /dev/null
+++ b/security-utils/src/main/java/com/yahoo/security/hpke/Constants.java
@@ -0,0 +1,38 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.security.hpke;
+
+import com.yahoo.security.ArrayUtils;
+
+/**
+ * Various internal constants used as part of key derivation etc. in HPKE
+ *
+ * @author vekterli
+ */
+final class Constants {
+
+    private static byte[] toBytes(String str) {
+        return ArrayUtils.toUtf8Bytes(str); // We only expect US-ASCII in practice, so UTF-8 is fine.
+    }
+
+    static final byte[] HPKE_V1_LABEL       = toBytes("HPKE-v1");
+    static final byte[] EMPTY_LABEL         = new byte[0];
+    static final byte[] EAE_PRK_LABEL       = toBytes("eae_prk");
+    static final byte[] SHARED_SECRET_LABEL = toBytes("shared_secret");
+
+    /**
+     * <pre>
+     * default_psk = ""
+     * default_psk_id = ""
+     * </pre>
+     */
+    static final byte[] DEFAULT_PSK    = new byte[0];
+    static final byte[] DEFAULT_PSK_ID = new byte[0];
+
+    static final byte[] PSK_ID_HASH_LABEL = toBytes("psk_id_hash");
+    static final byte[] INFO_HASH_LABEL   = toBytes("info_hash");
+    static final byte[] SECRET_LABEL      = toBytes("secret");
+    static final byte[] KEY_LABEL         = toBytes("key");
+    static final byte[] BASE_NONCE_LABEL  = toBytes("base_nonce");
+    static final byte[] EXP_LABEL         = toBytes("exp");
+
+}