Add Github controller and jwt helper

pom.xml

@@ -82,6 +82,34 @@
 			<artifactId>custom-war-packager-lib</artifactId>
 			<version>1.7</version>
 		</dependency>
+		<dependency>
+			<groupId>io.jsonwebtoken</groupId>
+			<artifactId>jjwt-jackson</artifactId>
+			<version>0.10.5</version>
+			<scope>runtime</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.jsonwebtoken</groupId>
+			<artifactId>jjwt-api</artifactId>
+			<version>0.10.5</version>
+		</dependency>
+    <dependency>
+      <groupId>io.jsonwebtoken</groupId>
+      <artifactId>jjwt-impl</artifactId>
+      <version>0.10.5</version>
+      <scope>runtime</scope>
+    </dependency>
+		<!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+			<version>29.0-jre</version>
+		</dependency>
+		<dependency>
+			<groupId>org.kohsuke</groupId>
+			<artifactId>github-api</artifactId>
+			<version>1.106</version>
+		</dependency>
 	</dependencies>
 
 	<licenses>

src/main/java/com/org/jenkins/custom/jenkins/distribution/service/GithubController.java

@@ -0,0 +1,56 @@
+package com.org.jenkins.custom.jenkins.distribution.service;
+
+import java.util.List;
+import org.kohsuke.github.GHApp;
+import org.kohsuke.github.GHAppInstallation;
+import org.kohsuke.github.GHAppInstallationToken;
+import org.kohsuke.github.GitHub;
+import org.kohsuke.github.GitHubBuilder;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.core.env.Environment;
+import org.springframework.web.bind.annotation.CrossOrigin;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import static com.org.jenkins.custom.jenkins.distribution.service.GithubJwtHelper.createJWT;
+import static com.org.jenkins.custom.jenkins.distribution.service.GithubJwtHelper.get;
+
+
+@RestController
+@CrossOrigin("*")
+public class GithubController {
+
+    @Value("${APP_IDENTIFIER}")
+    private String getAppIdentifier;
+
+    @PostMapping(path = "/event_handler")
+    public void handleEvent(@RequestBody String requestBodyString) throws Exception {
+        System.out.println("Received event handler event");
+        String token = authenticateApplication();
+        System.out.println(token);
+    }
+
+    @SuppressWarnings("deprecation")
+    private String authenticateApplication() {
+        try {
+            String APP_IDENTIFIER = getAppIdentifier.replaceAll("^\"+|\"+$", "");
+            String jwtToken = createJWT(APP_IDENTIFIER, 600000);
+            GitHub gitHubApp = new GitHubBuilder().withEndpoint("https://api.github.com").withJwtToken(jwtToken).build();
+            GHApp app = gitHubApp.getApp();
+            List<GHAppInstallation> appInstallations = app.listInstallations().asList();
+            if (!appInstallations.isEmpty()) {
+                GHAppInstallation appInstallation = appInstallations.get(0);
+                GHAppInstallationToken appInstallationToken = appInstallation
+                    .createToken(appInstallation.getPermissions())
+                    .create();
+                return appInstallationToken.getToken();
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+}

src/main/java/com/org/jenkins/custom/jenkins/distribution/service/GithubJwtHelper.java

@@ -0,0 +1,50 @@
+package com.org.jenkins.custom.jenkins.distribution.service;
+
+import io.jsonwebtoken.JwtBuilder;
+import io.jsonwebtoken.SignatureAlgorithm;
+import io.jsonwebtoken.Jwts;
+import java.io.File;
+import java.security.Key;
+import java.security.KeyFactory;
+import java.security.PrivateKey;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.util.Date;
+import com.google.common.io.Files;
+
+
+public class GithubJwtHelper {
+
+    static PrivateKey get(String filename) throws Exception {
+        byte[] keyBytes = Files.toByteArray(new File(filename));
+        PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);
+        KeyFactory kf = KeyFactory.getInstance("RSA");
+        return kf.generatePrivate(spec);
+    }
+
+    static String createJWT(String githubAppId, long ttlMillis) throws Exception {
+        //The JWT signature algorithm we will be using to sign the token
+        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.RS256;
+
+        long nowMillis = System.currentTimeMillis();
+        Date now = new Date(nowMillis);
+
+        //We will sign our JWT with our private key
+        Key signingKey = get("jenkins-custom-distribution-bot.der");
+
+        //Let's set the JWT Claims
+        JwtBuilder builder = Jwts.builder()
+            .setIssuedAt(now)
+            .setIssuer(githubAppId)
+            .signWith(signingKey, signatureAlgorithm);
+
+        //if it has been specified, let's add the expiration
+        if (ttlMillis > 0) {
+            long expMillis = nowMillis + ttlMillis;
+            Date exp = new Date(expMillis);
+            builder.setExpiration(exp);
+        }
+
+        //Builds the JWT and serializes it to a compact, URL-safe string
+        return builder.compact();
+    }
+}

src/main/resources/application.properties

@@ -1 +1 @@
-
+APP_IDENTIFIER = "71744"