// If the checksum fails, then FormatUnknown is returned.
func (b *block) getFormat() Format {
	// Verify checksum.
	var p parser
	value := p.parseOctal(b.toV7().chksum())
	chksum1, chksum2 := b.computeChecksum()
	if p.err != nil || (value != chksum1 && value != chksum2) {
		return FormatUnknown
	}

	// Guess the magic values.
	magic := string(b.toUSTAR().magic())
	version := string(b.toUSTAR().version())

				t.Fatalf("got %d headers, want %d headers", len(hdrs), len(v.headers))
			}

			for i, sum := range chksums {
				if i >= len(v.chksums) {
					t.Fatalf("entry %d: unexpected sum: got %s", i, sum)
				}
				if sum != v.chksums[i] {
					t.Fatalf("entry %d: incorrect checksum: got %s, want %s", i, sum, v.chksums[i])
				}
			}

			if err != v.err {
				t.Fatalf("unexpected error: got %v, want %v", err, v.err)

	for k, v := range c {
		if k == xhttp.AmzChecksumType {
			w.Header().Set(xhttp.AmzChecksumType, v)
			continue
		}
		cksum := NewChecksumString(k, v)
		if cksum == nil {
			continue
		}
		if cksum.Valid() {
			w.Header().Set(cksum.Type.Key(), v)
		}
	}
}

// GetContentChecksum returns content checksum.
// Returns ErrInvalidChecksum if so.

	fi.VersionID = opts.VersionID
	if opts.Versioned && fi.VersionID == "" {
		fi.VersionID = mustGetUUID()
	}
	fi.DataDir = mustGetUUID()

	if ckSum := userDefined[ReplicationSsecChecksumHeader]; ckSum != "" {
		v, err := base64.StdEncoding.DecodeString(ckSum)
		if err == nil {
			fi.Checksum = v
		}
		delete(userDefined, ReplicationSsecChecksumHeader)
	}

	// Initialize erasure metadata.

const minIOErasureUpgraded = "x-minio-internal-erasure-upgraded"

const erasureAlgorithm = "rs-vandermonde"

// GetChecksumInfo - get checksum of a part.
func (e ErasureInfo) GetChecksumInfo(partNumber int) (ckSum ChecksumInfo) {
	for _, sum := range e.Checksums {
		if sum.PartNumber == partNumber {
			// Return the checksum
			return sum
		}
	}
	return ChecksumInfo{Algorithm: DefaultBitrotAlgorithm}
}