implemented public api for verifying changeset signatures

scm-core/src/main/java/sonia/scm/repository/Changeset.java

@@ -32,6 +32,7 @@ import sonia.scm.util.ValidationUtil;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
@@ -85,6 +86,8 @@ public class Changeset extends BasicPropertiesAware implements ModelObject {
    */
   private Collection<Contributor> contributors;
 
+  private List<Signature> signatures;
+
   public Changeset() {}
 
   public Changeset(String id, Long date, Person author)
@@ -348,4 +351,34 @@ public class Changeset extends BasicPropertiesAware implements ModelObject {
       this.contributors.addAll(contributors);
     }
   }
+
+  /**
+   * Sets a collection of signatures which belong to this changeset.
+   * @param signatures collection of signatures
+   * @since 2.3.0
+   */
+  public void setSignatures(Collection<Signature> signatures) {
+    this.signatures = new ArrayList<>(signatures);
+  }
+
+  /**
+   * Returns a immutable list of signatures.
+   * @return signatures
+   * @since 2.3.0
+   */
+  public List<Signature> getSignatures() {
+    return Collections.unmodifiableList(signatures);
+  }
+
+  /**
+   * Adds a signature to the list of signatures.
+   * @param signature
+   * @since 2.3.0
+   */
+  public void addSignature(Signature signature) {
+    if (signatures == null) {
+      signatures = new ArrayList<>();
+    }
+    signatures.add(signature);
+  }
 }

scm-core/src/main/java/sonia/scm/repository/Signature.java

@@ -0,0 +1,47 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository;
+
+import lombok.Value;
+
+import java.util.Optional;
+
+/**
+ * Signature is the output of a signature verification.
+ * @since 2.3.0
+ */
+@Value
+public class Signature {
+
+  private final String key;
+  private final String type;
+  private final boolean verified;
+  private final String owner;
+
+  public Optional<String> getOwner() {
+    return Optional.ofNullable(owner);
+  }
+
+}