Put Object requests with Object Lock parameters require AWS Signature Version 4

Question

Cloud: AWS

SDK version: java-aws-sdk-1.10.49.

I want to evolve object locking for the object i am uploading .

Below is my code which is generating a aws signature 4 header but still i am unable to solve the issue.

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.TimeZone;
import java.util.TreeMap;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

public class AWSV4Auth {

    private AWSV4Auth() {
    }

    public static class Builder {

        private String accessKeyID;
        private String secretAccessKey;
        private String regionName;
        private String serviceName;
        private String httpMethodName;
        private String canonicalURI;
        private TreeMap<String, String> queryParametes;
        private TreeMap<String, String> awsHeaders;
        private String payload;
        private boolean debug = false;

        public Builder(String accessKeyID, String secretAccessKey) {
            this.accessKeyID = accessKeyID;
            this.secretAccessKey = secretAccessKey;
        }

        public Builder regionName(String regionName) {
            this.regionName = regionName;
            return this;
        }

        public Builder serviceName(String serviceName) {
            this.serviceName = serviceName;
            return this;
        }

        public Builder httpMethodName(String httpMethodName) {
            this.httpMethodName = httpMethodName;
            return this;
        }

        public Builder canonicalURI(String canonicalURI) {
            this.canonicalURI = canonicalURI;
            return this;
        }

        public Builder queryParametes(TreeMap<String, String> queryParametes) {
            this.queryParametes = queryParametes;
            return this;
        }

        public Builder awsHeaders(TreeMap<String, String> awsHeaders) {
            this.awsHeaders = awsHeaders;
            return this;
        }

        public Builder payload(String payload) {
            this.payload = payload;
            return this;
        }

        public Builder debug() {
            this.debug = true;
            return this;
        }

        public AWSV4Auth build() {
            return new AWSV4Auth(this);
        }
    }

    private String accessKeyID;
    private String secretAccessKey;
    private String regionName;
    private String serviceName;
    private String httpMethodName;
    private String canonicalURI;
    private TreeMap<String, String> queryParametes;
    private TreeMap<String, String> awsHeaders;
    private String payload;
    private boolean debug = false;

    /* Other variables */
    private final String HMACAlgorithm = "AWS4-HMAC-SHA256";
    private final String aws4Request = "aws4_request";
    private String strSignedHeader;
    private String xAmzDate;
    private String currentDate;

    private AWSV4Auth(Builder builder) {
        accessKeyID = builder.accessKeyID;
        secretAccessKey = builder.secretAccessKey;
        regionName = builder.regionName;
        serviceName = builder.serviceName;
        httpMethodName = builder.httpMethodName;
        canonicalURI = builder.canonicalURI;
        queryParametes = builder.queryParametes;
        awsHeaders = builder.awsHeaders;
        payload = builder.payload;
        debug = builder.debug;

        /* Get current timestamp value.(UTC) */
        xAmzDate = getTimeStamp();
        currentDate = getDate();
    }

    /**
     * Task 1: Create a Canonical Request for Signature Version 4.
     *
     * @return
     */
    private String prepareCanonicalRequest() {
        StringBuilder canonicalURL = new StringBuilder("");

        /* Step 1.1 Start with the HTTP request method (GET, PUT, POST, etc.), followed by a newline character. */
        canonicalURL.append(httpMethodName).append("\n");

        /* Step 1.2 Add the canonical URI parameter, followed by a newline character. */
        canonicalURI = canonicalURI == null || canonicalURI.trim().isEmpty() ? "/" : canonicalURI;
        canonicalURL.append(canonicalURI).append("\n");

        /* Step 1.3 Add the canonical query string, followed by a newline character. */
        StringBuilder queryString = new StringBuilder("");
        if (queryParametes != null && !queryParametes.isEmpty()) {
            for (Map.Entry<String, String> entrySet : queryParametes.entrySet()) {
                String key = entrySet.getKey();
                String value = entrySet.getValue();
                queryString.append(key).append("=").append(encodeParameter(value)).append("&");
            }

            /* @co-author https://github.com/dotkebi @git #1 @date 16th March, 2017 */
            queryString.deleteCharAt(queryString.lastIndexOf("&"));

            queryString.append("\n");
        } else {
            queryString.append("\n");
        }
        canonicalURL.append(queryString);

        /* Step 1.4 Add the canonical headers, followed by a newline character. */
        StringBuilder signedHeaders = new StringBuilder("");
        if (awsHeaders != null && !awsHeaders.isEmpty()) {
            for (Map.Entry<String, String> entrySet : awsHeaders.entrySet()) {
                String key = entrySet.getKey();
                String value = entrySet.getValue();
                signedHeaders.append(key).append(";");
                canonicalURL.append(key).append(":").append(value).append("\n");
            }

            /* Note: Each individual header is followed by a newline character, meaning the complete list ends with a newline character. */
            canonicalURL.append("\n");
        } else {
            canonicalURL.append("\n");
        }

        /* Step 1.5 Add the signed headers, followed by a newline character. */
        strSignedHeader = signedHeaders.substring(0, signedHeaders.length() - 1); // Remove last ";"
        canonicalURL.append(strSignedHeader).append("\n");

        /* Step 1.6 Use a hash (digest) function like SHA256 to create a hashed value from the payload in the body of the HTTP or HTTPS. */
        payload = payload == null ? "" : payload;
        canonicalURL.append(generateHex(payload));

        if (debug) {
            System.out.println("##Canonical Request:\n" + canonicalURL.toString());
        }

        return canonicalURL.toString();
    }

    /**
     * Task 2: Create a String to Sign for Signature Version 4.
     *
     * @param canonicalURL
     * @return
     */
    private String prepareStringToSign(String canonicalURL) {
        String stringToSign = "";

        /* Step 2.1 Start with the algorithm designation, followed by a newline character. */
        stringToSign = HMACAlgorithm + "\n";

        /* Step 2.2 Append the request date value, followed by a newline character. */
        stringToSign += xAmzDate + "\n";

        /* Step 2.3 Append the credential scope value, followed by a newline character. */
        stringToSign += currentDate + "/" + regionName + "/" + serviceName + "/" + aws4Request + "\n";

        /* Step 2.4 Append the hash of the canonical request that you created in Task 1: Create a Canonical Request for Signature Version 4. */
        stringToSign += generateHex(canonicalURL);

        if (debug) {
            System.out.println("##String to sign:\n" + stringToSign);
        }

        return stringToSign;
    }

    /**
     * Task 3: Calculate the AWS Signature Version 4.
     *
     * @param stringToSign
     * @return
     */
    private String calculateSignature(String stringToSign) {
        try {
            /* Step 3.1 Derive your signing key */
            byte[] signatureKey = getSignatureKey(secretAccessKey, currentDate, regionName, serviceName);

            /* Step 3.2 Calculate the signature. */
            byte[] signature = HmacSHA256(signatureKey, stringToSign);

            /* Step 3.2.1 Encode signature (byte[]) to Hex */
            String strHexSignature = bytesToHex(signature);
            return strHexSignature;
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    /**
     * Task 4: Add the Signing Information to the Request. We'll return Map of
     * all headers put this headers in your request.
     *
     * @return
     */
    public Map<String, String> getHeaders() {
        awsHeaders.put("x-amz-date", xAmzDate);

        /* Execute Task 1: Create a Canonical Request for Signature Version 4. */
        String canonicalURL = prepareCanonicalRequest();

        /* Execute Task 2: Create a String to Sign for Signature Version 4. */
        String stringToSign = prepareStringToSign(canonicalURL);

        /* Execute Task 3: Calculate the AWS Signature Version 4. */
        String signature = calculateSignature(stringToSign);

        if (signature != null) {
            Map<String, String> header = new HashMap<String, String>(0);
            header.put("x-amz-date", xAmzDate);
            header.put("Authorization", buildAuthorizationString(signature));

            if (debug) {
                System.out.println("##Signature:\n" + signature);
                System.out.println("##Header:");
                for (Map.Entry<String, String> entrySet : header.entrySet()) {
                    System.out.println(entrySet.getKey() + " = " + entrySet.getValue());
                }
                System.out.println("================================");
            }
            return header;
        } else {
            if (debug) {
                System.out.println("##Signature:\n" + signature);
            }
            return null;
        }
    }

    /**
     * Build string for Authorization header.
     *
     * @param strSignature
     * @return
     */
    private String buildAuthorizationString(String strSignature) {
        return HMACAlgorithm + " "
                + "Credential=" + accessKeyID + "/" + getDate() + "/" + regionName + "/" + serviceName + "/" + aws4Request + ","
                + "SignedHeaders=" + strSignedHeader + ","
                + "Signature=" + strSignature;
    }

    /**
     * Generate Hex code of String.
     *
     * @param data
     * @return
     */
    private String generateHex(String data) {
        MessageDigest messageDigest;
        try {
            messageDigest = MessageDigest.getInstance("SHA-256");
            messageDigest.update(data.getBytes("UTF-8"));
            byte[] digest = messageDigest.digest();
            return String.format("%064x", new java.math.BigInteger(1, digest));
        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * Apply HmacSHA256 on data using given key.
     *
     * @param data
     * @param key
     * @return
     * @throws Exception
     * @reference:
     * http://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html#signature-v4-examples-java
     */
    private byte[] HmacSHA256(byte[] key, String data) throws Exception {
        String algorithm = "HmacSHA256";
        Mac mac = Mac.getInstance(algorithm);
        mac.init(new SecretKeySpec(key, algorithm));
        return mac.doFinal(data.getBytes("UTF8"));
    }

    /**
     * Generate AWS signature key.
     *
     * @param key
     * @param date
     * @param regionName
     * @param serviceName
     * @return
     * @throws Exception
     * @reference
     * http://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html#signature-v4-examples-java
     */
    private byte[] getSignatureKey(String key, String date, String regionName, String serviceName) throws Exception {
        byte[] kSecret = ("AWS4" + key).getBytes("UTF8");
        byte[] kDate = HmacSHA256(kSecret, date);
        byte[] kRegion = HmacSHA256(kDate, regionName);
        byte[] kService = HmacSHA256(kRegion, serviceName);
        byte[] kSigning = HmacSHA256(kService, aws4Request);
        return kSigning;
    }

    final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();

    /**
     * Convert byte array to Hex
     *
     * @param bytes
     * @return
     */
    private String bytesToHex(byte[] bytes) {
        char[] hexChars = new char[bytes.length * 2];
        for (int j = 0; j < bytes.length; j++) {
            int v = bytes[j] & 0xFF;
            hexChars[j * 2] = hexArray[v >>> 4];
            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
        }
        return new String(hexChars).toLowerCase();
    }

    /**
     * Get timestamp. yyyyMMdd'T'HHmmss'Z'
     *
     * @return
     */
    private String getTimeStamp() {
        DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'");
        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));//server timezone
        return dateFormat.format(new Date());
    }

    /**
     * Get date. yyyyMMdd
     *
     * @return
     */
    private String getDate() {
        DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd");
        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));//server timezone
        return dateFormat.format(new Date());
    }


     private String encodeParameter(String param){
         try {
             return URLEncoder.encode(param, "UTF-8");
         } catch (Exception e) {
             return URLEncoder.encode(param);
         }
     }
}

Now the request containing my authorization header as below

AWS4-HMAC-SHA256 Credential=xxxx/xx/us-east-1/s3/aws4_request,SignedHeaders=content-type;x-amz-date;x-amz-object-lock-legal-hold;x-amz-object-lock-mode;x-amz-object-lock-retain-until-date,Signature=xxx

but still the below exception is coming please help

  com.amazonaws.services.s3.model.AmazonS3Exception: Put Object requests with Object Lock parameters require AWS Signature Version 4 (Service: Amazon S3; Status Code: 400; Error Code: InvalidArgument; Request ID: 30E27045CC75BD10), S3 Extended Request ID: sTQY2dy9o21y8iO0eeD/33V9DNjoLEwpElgyQi3S3FlC5P38DWRudzV1tErpON14pCAqUtJVHjM=
        at com.amazonaws.http.AmazonHttpClient.handleErrorResponse(AmazonHttpClient.java:1307)
        at com.amazonaws.http.AmazonHttpClient.executeOneRequest(AmazonHttpClient.java:894)
        at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:597)
        at com.amazonaws.http.AmazonHttpClient.doExecute(AmazonHttpClient.java:363)
        at com.amazonaws.http.AmazonHttpClient.executeWithTimer(AmazonHttpClient.java:329)
        at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:308)
        at com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Cli

ent.java:3659)

Answer 1

I would suggest you to not code the signature generation yourself, but leverage the implementation provided by the AWS SDK for Java instead.

This answer shows you how to do it How to generate Signature in AWS from Java