Slightly modified source code to calculate X-CS-Url-Signature

GetSignature.java

import java.util.*;
import java.lang.*;
import java.io.*;
import java.net.*;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.util.Locale;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

@SuppressWarnings("all")

public class GetURL
{

	private static class Preconditions
	{
		public static <T> T a(final T t) {
			if (t == null) {
				throw new NullPointerException();
			}
			return t;
		}

		public static void a() {
		}

		public static void a(final boolean b, final Object o) {
			if (!b) {
				throw new IllegalArgumentException(String.valueOf(o));
			}
		}
	}

	private interface TypedOutput
	{
		String fileName();

		long length();

		String mimeType();

		void writeTo(OutputStream p0) throws java.io.IOException;
	}


	private class JsonTypedOutput implements TypedOutput
	{
		public final byte[] a;
		private final String b;

		JsonTypedOutput(final byte[] a, final String s) {
			super();
			this.a = a;
			this.b = "application/json; charset=" + s;
		}

		@Override
		public String fileName() {
			return null;
		}

		@Override
		public long length() {
			return this.a.length;
		}

		@Override
		public String mimeType() {
			return this.b;
		}

		@Override
		public void writeTo(final OutputStream outputStream) throws java.io.IOException {
			outputStream.write(this.a);
		}
	}

	private final class Header
	{
		private final String name;
		private final String value;

		public Header(final String name, final String value) {
			super();
			this.name = name;
			this.value = value;
		}

		@Override
		public boolean equals(final Object o) {
			if (this != o) {
				if (o == null || this.getClass() != o.getClass()) {
					return false;
				}
				final Header header = (Header)o;
				Label_0059: {
					if (this.name != null) {
						if (this.name.equals(header.name)) {
							break Label_0059;
						}
					}
					else if (header.name == null) {
						break Label_0059;
					}
					return false;
				}
				if (this.value != null) {
					if (this.value.equals(header.value)) {
						return true;
					}
				}
				else if (header.value == null) {
					return true;
				}
				return false;
			}
			return true;
		}

		public String getName() {
			return this.name;
		}

		public String getValue() {
			return this.value;
		}

		@Override
		public int hashCode() {
			int hashCode;
			if (this.name != null) {
				hashCode = this.name.hashCode();
			}
			else {
				hashCode = 0;
			}
			final int n = hashCode * 31;
			final String value = this.value;
			int hashCode2 = 0;
			if (value != null) {
				hashCode2 = this.value.hashCode();
			}
			return n + hashCode2;
		}

		@Override
		public String toString() {
			final StringBuilder sb = new StringBuilder();
			String name;
			if (this.name != null) {
				name = this.name;
			}
			else {
				name = "";
			}
			final StringBuilder append = sb.append(name).append(": ");
			String value;
			if (this.value != null) {
				value = this.value;
			}
			else {
				value = "";
			}
			return append.append(value).toString();
		}
	}

	private final class Request
	{
		private final TypedOutput body;
		private final List<Header> headers;
		private final String method;
		private final String url;

		public Request(final String method, final String url, final List<Header> list, final TypedOutput body) {
			super();
			if (method == null) {
				throw new NullPointerException("Method must not be null.");
			}
			if (url == null) {
				throw new NullPointerException("URL must not be null.");
			}
			this.method = method;
			this.url = url;
			if (list == null) {
				this.headers = Collections.emptyList();
			}
			else {
				this.headers = Collections.unmodifiableList((List<? extends Header>)new ArrayList<Header>(list));
			}
			this.body = body;
		}

		public TypedOutput getBody() {
			return this.body;
		}

		public List<Header> getHeaders() {
			return this.headers;
		}

		public String getMethod() {
			return this.method;
		}

		public String getUrl() {
			return this.url;
		}
	}

	private static final class EncUtils
	{
		public static String a(final byte[] array) {
			return String.format(Locale.US, "%040x ", new BigInteger(1, array));
		}

		public static byte[] a(final byte[] array, final String s) {
			try {
				final Mac instance = Mac.getInstance("HmacSHA1");
				instance.init(new SecretKeySpec(s.getBytes(), "HmacSHA1"));
				return instance.doFinal(array);
			}
			catch (Exception ex) {
				throw new RuntimeException(ex);
			}
		}
	}

	private class RetrofitHttpClient
	{
		private final String a;
		private String b;

		public RetrofitHttpClient(final String a) {
			this.a = a;
		}

		private Request a(final Request request) throws java.net.MalformedURLException, UnsupportedEncodingException {
			final byte[] b = this.b(request.getUrl());
			byte[] a;
			if (request.getBody() != null && request.getBody() instanceof JsonTypedOutput) {
				System.out.println("body");
				a = this.a(b, ((JsonTypedOutput)request.getBody()).a);
			}
			else {
				a = b;
			}
			String s;
			if (this.b == null) {
				s = this.a;
			}
			else {
				s = this.a + "." + this.b;
			}

			final String a2 = EncUtils.a(EncUtils.a(a, s));
			System.out.println(a2);

			final ArrayList<Header> list = new ArrayList<Header>(request.getHeaders());
			list.add(new Header("X-CS-Url-Signature", a2));
			return new Request(request.getMethod(), request.getUrl(), list, request.getBody());
		}

		private byte[] a(final byte[] array, final byte[] array2) {
			final byte[] array3 = new byte[array.length + array2.length];
			System.arraycopy(array, 0, array3, 0, array.length);
			System.arraycopy(array2, 0, array3, array.length, array2.length);
			return array3;
		}

		private byte[] b(final String s) throws java.net.MalformedURLException, UnsupportedEncodingException {
			return s.substring(s.indexOf(new URL(s).getPath())).getBytes("UTF-8");
		}

		public void a(final String b) {
			this.b = b;
		}
	}

	private static final class RetrofitUtils
	{
		public static String a(final List<Header> list, final String s) {
			boolean b = true;
			Preconditions.a(list != null && b, "Headers argument shouldn't be null");
			if (s == null) {
				b = false;
			}
			Preconditions.a(b, "HeaderName argument shouldn't be null");
			for (final Header header : list) {
				if (s.equals(header.getName())) {
					return header.getValue();
				}
			}
			return null;
		}
	}

	private String getSignature() throws java.net.MalformedURLException, UnsupportedEncodingException, java.io.IOException {
		String data = new String("{\"actionType\":\"manual_login\",\"credentials\":{\"authToken\":\"qwerty\",\"email\":\"nzoakhvi@sharklasers.com\"}}");

		List<Header> headers = Arrays.asList(
			new Header("Accept-Encoding", "gzip, deflate"),
			new Header("Content-Type", "application/json; charset=utf-8"),
			new Header("User-Agent", "Couchsurfing/48 (iPhone; iOS 8.1.1; Scale/2.00) Couchsurfing/ios/48/3.0/"),
		);

		Request basicRequest = new Request("POST", "https://hapi.couchsurfing.com/api/v2/sessions", null, new JsonTypedOutput(data.getBytes("UTF-8"), "UTF-8"));
		// Request basicRequest = new Request("GET", "https://hapi.couchsurfing.com/api/v2/users/1003669205", headers, null);
		RetrofitHttpClient client = new RetrofitHttpClient("v3#!R3v44y3ZsJykkb$E@CG#XreXeGCh");
		Request localRequest = client.a(basicRequest);
		System.out.println(localRequest.getHeaders().size());
		// localRequest.getBody().writeTo(System.out);
		String str = RetrofitUtils.a(localRequest.getHeaders(), "X-CS-Url-Signature");
		return str;
	}

	public static void main (String[] args) throws java.lang.Exception, java.net.MalformedURLException
	{
		GetURL getURL = new GetURL();
		System.out.println(getURL.getSignature());
	}

}