return r.checksum
	}
	return r.ETag()[:]
}

// SHA256 returns the SHA256 checksum set as reference value.
//
// It corresponds to the checksum that is expected and
// not the actual SHA256 checksum of the content.
func (r *Reader) SHA256() []byte {
	return r.contentSHA256
}

// SHA256HexString returns a hex representation of the SHA256.
func (r *Reader) SHA256HexString() string {

				"X-Amz-SignedHeaders":  "host;x-amz-content-sha256;x-amz-date",
				"X-Amz-Credential":     fmt.Sprintf(credentialTemplate, accessKeyID, now.Format(yyyymmdd), region),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			headers: map[string]string{
				"X-Amz-Date":           now.AddDate(0, 0, -2).Format(iso8601Format),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			region:   region,

		// Test case with "X-Amz-Content-Sha256" header set, but to empty value but we can't skip.
		{"X-Amz-Content-Sha256", "", "", "", false},

		// Test case - 2.
		// Test case with "X-Amz-Content-Sha256" not set so we can skip.
		{"", "", "", "", true},

		// Test case - 3.
		// Test case with "X-Amz-Content-Sha256" header set to  "UNSIGNED-PAYLOAD"

	"github.com/minio/minio/internal/hash/sha256"
	xhttp "github.com/minio/minio/internal/http"
)

// Streaming AWS Signature Version '4' constants.
const (
	emptySHA256                   = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
	streamingContentSHA256        = "STREAMING-AWS4-HMAC-SHA256-PAYLOAD"
	streamingContentSHA256Trailer = "STREAMING-AWS4-HMAC-SHA256-PAYLOAD-TRAILER"

	contentLengthCondStr := `["content-length-range", 1024, 1048576]`
	// Add the algorithm condition, only accept AWS SignV4 Sha256.
	algorithmConditionStr := `["eq", "$x-amz-algorithm", "AWS4-HMAC-SHA256"]`
	// Add the date condition, only accept the current date.
	dateConditionStr := fmt.Sprintf(`["eq", "$x-amz-date", "%s"]`, t.Format(iso8601DateFormat))

			},
		},
		5: {
			desc:       "Correct sha256, nested",
			src:        mustReader(t, bytes.NewReader([]byte("abcd")), 4, "", "", 4),
			size:       4,
			actualSize: 4,
			sha256hex:  "88d4266fd4e6338d13b845fcf289579d209c897823b9217da3e161936f031589",
		},
		{
			desc:       "Correct sha256, nested, truncated",

	kexAlgoDH14SHA256             = "diffie-hellman-group14-sha256"
	kexAlgoDH16SHA512             = "diffie-hellman-group16-sha512"
	kexAlgoECDH256                = "ecdh-sha2-nistp256"
	kexAlgoECDH384                = "ecdh-sha2-nistp384"
	kexAlgoECDH521                = "ecdh-sha2-nistp521"
	kexAlgoCurve25519SHA256LibSSH = "curve25519-sha256@libssh.org"
	kexAlgoCurve25519SHA256       = "curve25519-sha256"

package hash

import (
	"bytes"
	"context"
	"crypto/sha1"
	"encoding/base64"
	"encoding/binary"
	"fmt"
	"hash"
	"hash/crc32"
	"net/http"
	"strings"

	"github.com/minio/minio/internal/hash/sha256"
	xhttp "github.com/minio/minio/internal/http"
	"github.com/minio/minio/internal/logger"
)

func hashLogIf(ctx context.Context, err error) {
	logger.LogIf(ctx, "hash", err)
}

				URL: &url.URL{
					Host:   "127.0.0.1:9000",
					Scheme: httpScheme,
					Path:   SlashSeparator,
				},
				Header: http.Header{
					"Authorization":        []string{"AWS4-HMAC-SHA256 <cred_string>"},
					"X-Amz-Content-Sha256": []string{streamingContentSHA256},
					"Content-Encoding":     []string{streamingContentEncoding},
				},
				Method: http.MethodPut,
				Body:   nopCloser,
			},

	{dataBlocks: 3, onDisks: 6, offDisks: 0, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: SHA256, shouldFail: false, shouldFailQuorum: false},                 // 1