Add basic tooling for public key encryption and decryption

Adds support for:
 * X25519 key pair generation
 * HPKE stream encryption with public key and token generation
 * HPKE stream decryption with private key

1 files changed, 19 insertions, 0 deletions

diff --git a/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/CliUtils.java b/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/CliUtils.java
new file mode 100644
index 00000000000..e9b348ab2a2
--- /dev/null
+++ b/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/CliUtils.java
@@ -0,0 +1,19 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.security.tool;
+
+import org.apache.commons.cli.CommandLine;
+
+/**
+ * @author vekterli
+ */
+public class CliUtils {
+
+    public static String optionOrThrow(CommandLine arguments, String option) {
+        var value = arguments.getOptionValue(option);
+        if (value == null) {
+            throw new IllegalArgumentException("Required argument '--%s' must be provided".formatted(option));
+        }
+        return value;
+    }
+
+}