From 9f48875d57e72d2c1fc94eb4aa536c1b0bc2e6f4 Mon Sep 17 00:00:00 2001
From: Rene Pfeuffer <rene.pfeuffer@cloudogu.com>
Date: Thu, 17 Oct 2019 09:23:37 +0200
Subject: [PATCH] POC

---
 scm-plugins/scm-git-plugin/pom.xml            |   6 ++
 .../main/java/sonia/scm/LFSAuthCommand.java   | 101 ++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 scm-plugins/scm-git-plugin/src/main/java/sonia/scm/LFSAuthCommand.java

diff --git a/scm-plugins/scm-git-plugin/pom.xml b/scm-plugins/scm-git-plugin/pom.xml
index 0456370c99..0cace5e94d 100644
--- a/scm-plugins/scm-git-plugin/pom.xml
+++ b/scm-plugins/scm-git-plugin/pom.xml
@@ -40,6 +40,12 @@
       <version>2.6</version>
     </dependency>
 
+    <dependency>
+      <groupId>org.jboss.resteasy</groupId>
+      <artifactId>resteasy-jackson2-provider</artifactId>
+      <version>${resteasy.version}</version>
+    </dependency>
+
   </dependencies>
 
   <build>
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/LFSAuthCommand.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/LFSAuthCommand.java
new file mode 100644
index 0000000000..0864b84dfd
--- /dev/null
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/LFSAuthCommand.java
@@ -0,0 +1,101 @@
+package sonia.scm;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.module.jaxb.JaxbAnnotationModule;
+import sonia.scm.plugin.Extension;
+import sonia.scm.protocolcommand.CommandInterpreter;
+import sonia.scm.protocolcommand.CommandInterpreterFactory;
+import sonia.scm.protocolcommand.RepositoryContext;
+import sonia.scm.protocolcommand.RepositoryContextResolver;
+import sonia.scm.protocolcommand.ScmCommandProtocol;
+import sonia.scm.security.AccessToken;
+import sonia.scm.security.AccessTokenBuilderFactory;
+
+import javax.inject.Inject;
+import javax.xml.bind.annotation.XmlElement;
+import java.io.ByteArrayOutputStream;
+import java.text.SimpleDateFormat;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.Date;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+
+@Extension
+public class LFSAuthCommand implements CommandInterpreterFactory {
+
+  private final AccessTokenBuilderFactory tokenBuilderFactory;
+
+  @Inject
+  public LFSAuthCommand(AccessTokenBuilderFactory tokenBuilderFactory) {
+    this.tokenBuilderFactory = tokenBuilderFactory;
+  }
+
+  @Override
+  public Optional<CommandInterpreter> canHandle(String command) {
+    return command.startsWith("git-lfs-authenticate") ? Optional.of(new CommandInterpreter() {
+      @Override
+      public String[] getParsedArgs() {
+        return new String[0];
+      }
+
+      @Override
+      public ScmCommandProtocol getProtocolHandler() {
+        return (context, repositoryContext) -> {
+          AccessToken accessToken = tokenBuilderFactory.create().expiresIn(5, TimeUnit.MINUTES).build();
+
+          ObjectMapper objectMapper = new ObjectMapper();
+          objectMapper.registerModule(new JaxbAnnotationModule());
+          objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd'T'HH:MM:ss'Z'"));
+          LfsAuthResponse response = new LfsAuthResponse("http://localhost:8081/scm/repo/scmadmin/lfs.git/info/lfs/", new LfsAuthHeader(accessToken.compact()), Instant.now().plus(5, ChronoUnit.MINUTES));
+          ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+          objectMapper.writeValue(buffer, response);
+          context.getOutputStream().write(buffer.toString().getBytes());
+        };
+      }
+
+      @Override
+      public RepositoryContextResolver getRepositoryContextResolver() {
+        return args -> new RepositoryContext(null, null);
+      }
+    }) : Optional.empty();
+  }
+
+  private class LfsAuthResponse {
+    private final String href;
+    private final LfsAuthHeader header;
+    @XmlElement(name = "expires_at")
+    private final Date expiresAt;
+
+    public LfsAuthResponse(String href, LfsAuthHeader header, Instant expiresAt) {
+      this.href = href;
+      this.header = header;
+      this.expiresAt = Date.from(expiresAt);
+    }
+
+    public String getHref() {
+      return href;
+    }
+
+    public LfsAuthHeader getHeader() {
+      return header;
+    }
+
+    public Date getExpiresAt() {
+      return expiresAt;
+    }
+  }
+
+  private class LfsAuthHeader {
+    @XmlElement(name = "Authorization")
+    private final String authorization;
+
+    public LfsAuthHeader(String authorization) {
+      this.authorization = authorization;
+    }
+
+    public String getAuthorization() {
+      return "Bearer " + authorization;
+    }
+  }
+}