From 43335cbcd3b646d49102c558001adaa55d2a5c0a Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Wed, 30 Aug 2023 16:22:21 +0200
Subject: [PATCH] Kotlin conversion: SessionKey

---
 .../java/org/pgpainless/util/SessionKey.java  | 66 -------------------
 .../kotlin/org/pgpainless/util/SessionKey.kt  | 48 ++++++++++++++
 2 files changed, 48 insertions(+), 66 deletions(-)
 delete mode 100644 pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java
 create mode 100644 pgpainless-core/src/main/kotlin/org/pgpainless/util/SessionKey.kt

diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java b/pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java
deleted file mode 100644
index 1e71bb03..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java
+++ /dev/null
@@ -1,66 +0,0 @@
-// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.util;
-
-import javax.annotation.Nonnull;
-
-import org.bouncycastle.openpgp.PGPSessionKey;
-import org.bouncycastle.util.encoders.Hex;
-import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
-
-/**
- * A {@link SessionKey} is the symmetric key that is used to encrypt/decrypt an OpenPGP message.
- * The OpenPGP message header contains a copy of the session key, encrypted for the public key of each recipient.
- */
-public class SessionKey {
-
-    private final SymmetricKeyAlgorithm algorithm;
-    private final byte[] key;
-
-    /**
-     * Constructor to create a session key from a BC {@link PGPSessionKey} object.
-     *
-     * @param sessionKey BC session key
-     */
-    public SessionKey(@Nonnull PGPSessionKey sessionKey) {
-        this(SymmetricKeyAlgorithm.requireFromId(sessionKey.getAlgorithm()), sessionKey.getKey());
-    }
-
-    /**
-     * Create a session key object from an algorithm and a key.
-     *
-     * @param algorithm algorithm
-     * @param key key
-     */
-    public SessionKey(@Nonnull SymmetricKeyAlgorithm algorithm, @Nonnull byte[] key) {
-        this.algorithm = algorithm;
-        this.key = key;
-    }
-
-    /**
-     * Return the symmetric key algorithm.
-     *
-     * @return algorithm
-     */
-    public SymmetricKeyAlgorithm getAlgorithm() {
-        return algorithm;
-    }
-
-    /**
-     * Return the bytes of the key.
-     *
-     * @return key
-     */
-    public byte[] getKey() {
-        byte[] copy = new byte[key.length];
-        System.arraycopy(key, 0, copy, 0, copy.length);
-        return copy;
-    }
-
-    @Override
-    public String toString() {
-        return "" + getAlgorithm().getAlgorithmId() + ":" + Hex.toHexString(getKey());
-    }
-}
diff --git a/pgpainless-core/src/main/kotlin/org/pgpainless/util/SessionKey.kt b/pgpainless-core/src/main/kotlin/org/pgpainless/util/SessionKey.kt
new file mode 100644
index 00000000..894d0869
--- /dev/null
+++ b/pgpainless-core/src/main/kotlin/org/pgpainless/util/SessionKey.kt
@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.util
+
+import org.bouncycastle.openpgp.PGPSessionKey
+import org.bouncycastle.util.encoders.Hex
+import org.pgpainless.algorithm.SymmetricKeyAlgorithm
+
+/**
+ * A [SessionKey] is the symmetric key that is used to encrypt/decrypt an OpenPGP message payload.
+ * The OpenPGP message header contains a copy of the session key, encrypted for the public key of each recipient.
+ *
+ * @param algorithm symmetric key algorithm
+ * @param key bytes of the key
+ */
+data class SessionKey(val algorithm: SymmetricKeyAlgorithm,
+        val key: ByteArray) {
+
+    /**
+     * Constructor to create a session key from a BC [PGPSessionKey] object.
+     *
+     * @param sessionKey BC session key
+     */
+    constructor(sessionKey: PGPSessionKey):
+            this(SymmetricKeyAlgorithm.requireFromId(sessionKey.algorithm), sessionKey.key)
+
+    override fun toString(): String {
+        return "${algorithm.algorithmId}:${Hex.toHexString(key)}"
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as SessionKey
+
+        if (algorithm != other.algorithm) return false
+        if (!key.contentEquals(other.key)) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        return 31 * algorithm.hashCode() + key.contentHashCode()
+    }
+}
\ No newline at end of file