*
     * @param algorithm the compression algorithm to check
     * @return true if the algorithm is supported
     */
    boolean isAlgorithmSupported(int algorithm);

    /**
     * Gets the list of supported compression algorithms.
     *
     * @return array of supported algorithm constants
     */
    int[] getSupportedAlgorithms();

    /**

    public static MessageDigest getInstance(final String algorithm) {
        assertArgumentNotEmpty("algorithm", algorithm);

        try {
            return MessageDigest.getInstance(algorithm);
        } catch (final NoSuchAlgorithmException e) {
            throw new NoSuchAlgorithmRuntimeException(e);
        }
    }

    /**
     * Hashes the specified text using the given algorithm and converts it to a string.
     *

	}
	for algorithm := range bitrotAlgorithms {
		if !algorithm.Available() {
			continue
		}

		checksum, err := hex.DecodeString(checksums[algorithm])
		if err != nil {
			logger.Fatal(errSelfTestFailure, fmt.Sprintf("bitrot: failed to decode %v checksum %s for selftest: %v", algorithm, checksums[algorithm], err))
		}
		var (
			hash = algorithm.New()

    MESSAGE_DIGEST_API() {
      @Override
      public byte[] hash(Algorithm algorithm, byte[] input) {
        MessageDigest md = algorithm.getMessageDigest();
        md.update(input);
        return md.digest();
      }
    },
    HASH_FUNCTION_DIRECT() {
      @Override
      public byte[] hash(Algorithm algorithm, byte[] input) {
        return algorithm.getHashFunction().hashBytes(input).asBytes();
      }
    },

    MESSAGE_DIGEST_API() {
      @Override
      public byte[] hash(Algorithm algorithm, byte[] input) {
        MessageDigest md = algorithm.getMessageDigest();
        md.update(input);
        return md.digest();
      }
    },
    HASH_FUNCTION_DIRECT() {
      @Override
      public byte[] hash(Algorithm algorithm, byte[] input) {
        return algorithm.getHashFunction().hashBytes(input).asBytes();
      }
    },

    /**
     * Validates if the compression algorithm is known.
     *
     * @param algorithm the algorithm to validate
     * @return true if the algorithm is known
     */
    private boolean isValidCompressionAlgorithm(int algorithm) {
        return algorithm == COMPRESSION_NONE || algorithm == COMPRESSION_LZ77 || algorithm == COMPRESSION_LZ77_HUFFMAN

     * @param algorithms  The checksum algorithms to use, must not be {@code null}.
     * @return The calculated checksums, indexed by algorithms, never {@code null}.
     * @throws NullPointerException if passed in any parameter is {@code null}.
     */
    @Nonnull
    Map<ChecksumAlgorithm, String> calculate(@Nonnull byte[] data, @Nonnull Collection<ChecksumAlgorithm> algorithms);

    /**

)

const (
	// AES256 is used with SSE-S3
	AES256 Algorithm = "AES256"
	// AWSKms is used with SSE-KMS
	AWSKms Algorithm = "aws:kms"
)

// Algorithm - represents valid SSE algorithms supported; currently only AES256 is supported
type Algorithm string

// UnmarshalXML - Unmarshals XML tag to valid SSE algorithm
func (alg *Algorithm) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	var s string

	Dir     bool      `json:"dir"`
	Mode    uint32    `json:"mode"`
}

// ErasureInfo holds erasure coding and bitrot related information.
type ErasureInfo struct {
	// Algorithm is the string representation of erasure-coding-algorithm
	Algorithm string `json:"algorithm"`
	// DataBlocks is the number of data blocks for erasure-coding
	DataBlocks int `json:"data"`
	// ParityBlocks is the number of parity blocks for erasure-coding

	}
	if algorithm != SealAlgorithm && algorithm != InsecureSealAlgorithm {
		return sealedKey, errInvalidInternalSealAlgorithm
	}
	encryptedKey, err := base64.StdEncoding.DecodeString(b64SealedKey)
	if err != nil || len(encryptedKey) != 64 {
		return sealedKey, Errorf("The internal sealed key for SSE-C is invalid")
	}

	sealedKey.Algorithm = algorithm
	copy(sealedKey.IV[:], iv)