Generate Auth token – call Cosmos DB SQL REST APIs

Generate Authorization token – Cosmos DB REST APIs –  we have to generate it as per REST api call we are making.

More details about Cosmos DB – https://docs.microsoft.com/en-us/rest/api/cosmos-db/access-control-on-cosmosdb-resources

For POC we will create Authorization token for calling create document in Cosmos DB collection

To do this in MuleSoft application we have to add following repository and dependency in pom.xml

Dependency

<dependency>
	<groupId>com.microsoft.azure</groupId>
	<artifactId>azure-documentdb</artifactId>
	<version>2.1.2</version>
</dependency>

Repository

<repository>
	<id>mulesoft-azure-releases</id>
	<name>MuleSoft Releases Repository Azure</name>
	<url>https://mvnrepository.com/artifact/</url>
	<layout>default</layout>
</repository>

Updated pom.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.mycompany</groupId>
	<artifactId>cosmos-db-sample</artifactId>
	<version>1.0.0-SNAPSHOT</version>
	<packaging>mule-application</packaging>
	<name>cosmos-db-sample</name>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

		<app.runtime>4.2.2</app.runtime>
		<mule.maven.plugin.version>3.2.7</mule.maven.plugin.version>
	</properties>

	<build>
		<plugins>
			<plugin>
				<groupId>org.mule.tools.maven</groupId>
				<artifactId>mule-maven-plugin</artifactId>
				<version>${mule.maven.plugin.version}</version>
				<extensions>true</extensions>
				<configuration>
				<classifier>mule-application</classifier>
				</configuration>
			</plugin>
		</plugins>
	</build>

	<dependencies>
		<dependency>
			<groupId>org.mule.connectors</groupId>
			<artifactId>mule-http-connector</artifactId>
			<version>1.2.1</version>
			<classifier>mule-plugin</classifier>
		</dependency>
		<dependency>
			<groupId>org.mule.connectors</groupId>
			<artifactId>mule-sockets-connector</artifactId>
			<version>1.1.1</version>
			<classifier>mule-plugin</classifier>
		</dependency>
		<dependency>
			<groupId>com.microsoft.azure</groupId>
			<artifactId>azure-documentdb</artifactId>
			<version>2.1.2</version>
		</dependency>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-log4j12</artifactId>
			<version>1.7.5</version>
		</dependency>
	</dependencies>

	<repositories>
		  <repository>
			<id>anypoint-exchange</id>
			<name>Anypoint Exchange</name>
			<url>https://maven.anypoint.mulesoft.com/api/v1/maven</url>
			<layout>default</layout>
		</repository>
		<repository>
			<id>mulesoft-releases</id>
			<name>MuleSoft Releases Repository</name>
			<url>https://repository.mulesoft.org/releases/</url>
			<layout>default</layout>
		</repository>
		<repository>
			<id>mulesoft-azure-releases</id>
			<name>MuleSoft Releases Repository Azure</name>
			<url>https://mvnrepository.com/artifact/</url>
			<layout>default</layout>
		</repository>
	</repositories>
	<pluginRepositories>
		<pluginRepository>
			<id>mulesoft-releases</id>
			<name>mulesoft release repository</name>
			<layout>default</layout>
			<url>https://repository.mulesoft.org/releases/</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</pluginRepository>
	</pluginRepositories>

</project>

This will add the required dependency jar in our mule application

Now create GenerateCosmosDBAuthToken Class in mule application

Java code

package cosmosdb;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.text.SimpleDateFormat;
import java.util.Base64;
import java.util.Calendar;
import java.util.Locale;
import java.util.TimeZone;

public class GenerateCosmosDBAuthToken {

	public static String generate(String verb, String resourceType, String resourceId, String key, String keyType, String tokenVersion, String date)
	{
		 String authorization = null;
		 System.out.println(date);
		 String payload=verb.toLowerCase()+"\n"
		 +resourceType.toLowerCase()+"\n"
		 +resourceId+"\n"
		 +date.toLowerCase()+"\n"
		 +""+"\n";
		 Mac sha256_HMAC;
		try {
			sha256_HMAC = Mac.getInstance("HmacSHA256");
		
		 SecretKeySpec secret_key = new SecretKeySpec(Base64.getDecoder().decode(key), "HmacSHA256");
		 sha256_HMAC.init(secret_key);
		 String signature = Base64.getEncoder().encodeToString(sha256_HMAC.doFinal(payload.getBytes("UTF-8")));
		 authorization=URLEncoder.encode("type="+keyType+"&ver="+tokenVersion+"&sig="+signature, "utf-8");
		 System.out.println(authorization);
		}catch (InvalidKeyException e) {
			e.printStackTrace();
		} 
		catch (NoSuchAlgorithmException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		catch (IllegalStateException e) {
			e.printStackTrace();
		} 
		catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return authorization;
	}
	
	public static String getServerTime() {
		Calendar calendar = Calendar.getInstance();
		SimpleDateFormat dateFormat = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z", Locale.US);
		dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
		return dateFormat.format(calendar.getTime());
	}
}

Here we have two static methods

getServerTime – this will provide the server time in our desired format

generate – This will return the required Auth token

arguments in generate method:

• • Verb – REST API method e.g. POST, GET, PUT
  • resourceType – type of resource that the request is for, Eg. “dbs”, “colls”, “docs”.
  • resourceId – ResourceLink must maintain its case for the ID of the resource. Example, for a collection it looks like: “dbs/MyDatabase/colls/MyCollection”
  • key – PRIMARY KEY from keys section in Azure Cosmos DB details – please see this for more details
  • keyType – master as we are using primary key
  • tokenVersion – 1.0 default
  • date – the date we generated using getServerTime method call

More details about the argument – https://docs.microsoft.com/en-us/rest/api/cosmos-db/access-control-on-cosmosdb-resources#constructkeytoken

Now to generate Auth token through Dataweave

Dataweave

%dw 2.0
import java!cosmosdb::GenerateCosmosDBAuthToken
output application/java
var verb = "POST"
var resourceType = "docs" 
var resourceId = "dbs/hr/colls/employee"
var key = "0SZd1Zs3hySH915hKBTQCbewWnzIEI4S2YK8yHDaRwMrnzrZSwaa0hHy8IW21x4qbsQoswWIh3FW8TOd0fpSYw=="
var keyType = "master"
var tokenVersion = "1.0"
var serverDateTime = GenerateCosmosDBAuthToken::getServerTime() as String
---
{
	serverDateTime: serverDateTime,
	authKey: GenerateCosmosDBAuthToken::generate(verb, resourceType, resourceId, key, keyType, tokenVersion, serverDateTime)
}

This will generate both serverDateTime and authkey

Testing the application through SOAP UI

In Azure we can see the document

Sample application – cosmos-db-sample

Sample SOAP application – Cosmos-db-soapui-project