expectedMin int64
	expectedMax int64

	size       int64
	actualSize int64

	checksum      etag.ETag
	contentSHA256 []byte

	// Client-provided content checksum
	contentHash   Checksum
	contentHasher hash.Hash
	disableMD5    bool

	// Server side computed checksum. In some cases, like CopyObject, a new checksum
	// needs to be computed and saved on the destination object, but the client

	if err != nil {
		return levent.Event{}, err
	}

	ckSum := sha256.Sum256([]byte(cred.AccessKey + u.RawQuery))

	eventData := levent.Event{
		GetObjectContext: &levent.GetObjectContext{
			InputS3URL:  u.String(),
			OutputRoute: shortuuid.New(),
			OutputToken: hex.EncodeToString(ckSum[:]),
		},
		UserRequest: levent.UserRequest{
			URL:     r.URL.String(),
			Headers: r.Header.Clone(),

  /**
   * Returns a hash function implementing the CRC-32 checksum algorithm (32 hash bits).
   *
   * <p>To get the {@code long} value equivalent to {@link Checksum#getValue()} for a {@code
   * HashCode} produced by this function, use {@link HashCode#padToLong()}.
   *
   * <p>This function is best understood as a <a
   * href="https://en.wikipedia.org/wiki/Checksum">checksum</a> rather than a true <a

	AmzFwdHeaderContentType        = "x-amz-fwd-header-Content-Type"
	AmzFwdHeaderChecksumCrc32      = "x-amz-fwd-header-x-amz-checksum-crc32"
	AmzFwdHeaderChecksumCrc32c     = "x-amz-fwd-header-x-amz-checksum-crc32c"
	AmzFwdHeaderChecksumSha1       = "x-amz-fwd-header-x-amz-checksum-sha1"
	AmzFwdHeaderChecksumSha256     = "x-amz-fwd-header-x-amz-checksum-sha256"
	AmzFwdHeaderDeleteMarker       = "x-amz-fwd-header-x-amz-delete-marker"

		},
		{
			name:    "unknown key XAmzChecksumCRC32 is error as it does not appear in policy",
			fv:      defaultFormVals.Clone().Set(http.CanonicalHeaderKey(xhttp.AmzChecksumCRC32), "crc32-val"),
			wantErr: `Each form field that you specify in a form must appear in the list of policy conditions. "X-Amz-Checksum-Crc32" not specified in the policy.`,
		},

  }

  private static void assertChecksum(ImmutableSupplier<Checksum> supplier, String input) {
    byte[] bytes = HashTestUtils.ascii(input);

    Checksum checksum = supplier.get();
    checksum.update(bytes, 0, bytes.length);
    long value = checksum.getValue();

    String toString = "name";
    HashFunction func = new ChecksumHashFunction(supplier, 32, toString);

	r.md5.Write(p[:n])

	if err == io.EOF && len(r.checksum) != 0 {
		if etag := r.ETag(); !Equal(etag, r.checksum) {
			return n, VerifyError{
				Expected: r.checksum,
				Computed: etag,
			}
		}
	}
	return n, err
}

// ETag returns the ETag of all the content read
// so far. Reading more content changes the MD5
// checksum. Therefore, calling ETag multiple
// times may return different results.

import org.eclipse.aether.internal.impl.checksum.DefaultChecksumAlgorithmFactorySelector;
import org.eclipse.aether.internal.impl.checksum.Md5ChecksumAlgorithmFactory;
import org.eclipse.aether.internal.impl.checksum.Sha1ChecksumAlgorithmFactory;
import org.eclipse.aether.internal.impl.checksum.Sha256ChecksumAlgorithmFactory;
import org.eclipse.aether.internal.impl.checksum.Sha512ChecksumAlgorithmFactory;

        wagon.clearExpectedContent();
        wagon.addExpectedContent("path", "lower-case-checksum");
        wagon.addExpectedContent("path.sha1", "2a25dc564a3b34f68237fc849066cbc7bb7a36a1");
        wagonManager.getArtifact(artifact, repo, null, false);

        wagon.clearExpectedContent();
        wagon.addExpectedContent("path", "upper-case-checksum");
        wagon.addExpectedContent("path.sha1", "B7BB97D7D0B9244398D9B47296907F73313663E6");

            log.trace(String.format("Checksum data %s type %d signature %s", Hexdump.toHexString(checksumData),
                    this.serverSignature.getType(), Hexdump.toHexString(this.serverSignature.getChecksum())));
        }

        byte checksum[] = PacMac.calculateMac(this.serverSignature.getType(), keys, checksumData);
        if (!MessageDigest.isEqual(this.serverSignature.getChecksum(), checksum)) {
            if (log.isDebugEnabled()) {