ctx := r.Context()

	objAPI, cred := validateAdminReq(ctx, w, r, policy.SetTierAction)
	if objAPI == nil {
		return
	}

	password := cred.SecretKey
	reqBytes, err := madmin.DecryptData(password, io.LimitReader(r.Body, r.ContentLength))
	if err != nil {
		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrAdminConfigBadJSON, err), r.URL)
		return
	}

	}

	// The credentials package in minio-go provides an interface to call the
	// STS API.

	// Initialize credential options
	var stsOpts cr.STSAssumeRoleOptions
	stsOpts.AccessKey = minioUsername
	stsOpts.SecretKey = minioPassword

	if sessionPolicyFile != "" {
		var policy string
		if f, err := os.Open(sessionPolicyFile); err != nil {
			log.Fatalf("Unable to open session policy file: %v", err)
		} else {
			defer f.Close()

			sum := sha256.Sum256(body)
			req.Header.Set("X-Amz-Content-Sha256", hex.EncodeToString(sum[:]))
			req = signer.SignV4(*req, credentials.AccessKey, credentials.SecretKey, "", "us-east-1")

			rec := httptest.NewRecorder()
			api := objectAPIHandlers{
				ObjectAPI: func() ObjectLayer {
					return obj
				},
			}
			api.GetObjectLambdaHandler(rec, req)

### GNU/Linux

```sh
sudo chroot --userspec username:group /mnt/export/${USER} /bin/minio --config-dir=/.minio server /data

Endpoint:  http://192.168.1.92:9000  http://65.19.167.92:9000
AccessKey: MVPSPBW4NP2CMV1W3TXD
SecretKey: X3RKxEeFOI8InuNWoPsbG+XEVoaJVCqbvxe+PTOa
...
...
```

Instance is now accessible on the host at port 9000, proceed to access the Web browser at <http://127.0.0.1:9000/>

## Explore Further

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import javax.crypto.SecretKey;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

/**
 * Test class for SecureKeyManager
 */
public class SecureKeyManagerTest {

```
go run client-grants.go -cid PoEgXP6uVO45IsENRngDXj5Au5Ya -csec eKsw6z8CtOJVBtrOWvhRWL4TUCga

##### Credentials
{
 "accessKey": "IRBLVDGN5QGMDCMO1X8V",
 "secretKey": "KzS3UZKE7xqNdtRbKyfcWgxBS6P1G4kwZn4DXKuY",
 "expiration": "2018-08-21T15:49:38-07:00",

	mkdir -p "$WORK_DIR"
	mkdir -p "$MINIO_CONFIG_DIR"

	## version is purposefully set to '3' for minio to migrate configuration file
	echo '{"version": "3", "credential": {"accessKey": "minio", "secretKey": "minio123"}, "region": "us-east-1"}' >"$MINIO_CONFIG_DIR/config.json"

	if [ ! -f /tmp/mc ]; then
		wget --quiet -O /tmp/mc https://dl.minio.io/client/mc/release/linux-amd64/mc &&
			chmod +x /tmp/mc
	fi
}

		getScope(cr.seedDate, cr.region) + "\n" +
		cr.seedSignature + "\n" +
		emptySHA256 + "\n" +
		hashedChunk

	// Get hmac signing key.
	signingKey := getSigningKey(cr.cred.SecretKey, cr.seedDate, cr.region, serviceS3)

	// Calculate signature.
	newSignature := getSignature(signingKey, stringToSign)

	return newSignature
}

// getTrailerChunkSignature - get trailer chunk signature.

        result = ParameterUtil.encrypt(value);
        assertTrue(result.contains("password={cipher}5691346cc398a4450114883140fa84a7"));
        assertTrue(result.contains("secretkey={cipher}"));
        assertFalse(result.contains("secretkey=unencrypted"));

        // Test with keys that don't match pattern
        value = "normalfield=value\npassword=secret";
        result = ParameterUtil.encrypt(value);

```

Note: In the case of S3, it is possible to create a tier from MinIO running in EC2 to S3 using AWS role attached to EC2 as credentials instead of accesskey/secretkey:

```
mc admin tier add s3 source S3TIER --bucket s3bucket --prefix testprefix/ --use-aws-role
```