Created
September 8, 2015 21:45
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| package ot.security; | |
| import java.io.IOException; | |
| import java.io.InputStream; | |
| import java.nio.file.Files; | |
| import java.nio.file.Path; | |
| import java.security.MessageDigest; | |
| import java.security.NoSuchAlgorithmException; | |
| /** | |
| * Initial draft for a fluent API to use hashes like MD5, SHA and so on. | |
| * | |
| * @author Otávio S Garcia | |
| */ | |
| public final class Sha3Hasher { | |
| private static final int BUFFER_SIZE = 4096; | |
| public static String checksum512(Path path) { | |
| MessageDigest md = getSha3Algorithm(); | |
| try (InputStream stream = Files.newInputStream(path)) { | |
| byte[] dataBytes = new byte[BUFFER_SIZE]; | |
| int nread = 0; | |
| while ((nread = stream.read(dataBytes)) != -1) { | |
| md.update(dataBytes, 0, nread); | |
| } | |
| } catch (IOException e) { | |
| throw new ChecksumException(e); | |
| } | |
| return toHex(md.digest()); | |
| } | |
| private static MessageDigest getSha3Algorithm() { | |
| try { | |
| return MessageDigest.getInstance("SHA3-512"); | |
| } catch (NoSuchAlgorithmException e) { | |
| throw new ChecksumException("SHA3-512 algorithm not found. Please install Bouncy Castle API.", e); | |
| } | |
| } | |
| private static String toHex(byte[] data) { | |
| StringBuilder hexStr = new StringBuilder(data.length * 2); | |
| for (int i = 0; i < data.length; i++) { | |
| hexStr.append(Character.forDigit((data[i] >> 4) & 0xF, 16)); | |
| hexStr.append(Character.forDigit((data[i] & 0xF), 16)); | |
| } | |
| return hexStr.toString(); | |
| } | |
| // TODO externalize | |
| public static class ChecksumException extends IllegalStateException { | |
| private static final long serialVersionUID = 1L; | |
| public ChecksumException(Throwable cause) { | |
| super(cause); | |
| } | |
| public ChecksumException(String message, Throwable cause) { | |
| super(message, cause); | |
| } | |
| } | |
| } |
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| package ot.security; | |
| import static org.hamcrest.Matchers.is; | |
| import static org.junit.Assert.assertThat; | |
| import static ot.security.Sha3Hasher.checksum512; | |
| import java.nio.charset.StandardCharsets; | |
| import java.nio.file.Files; | |
| import java.nio.file.Path; | |
| import org.junit.Rule; | |
| import org.junit.Test; | |
| import org.junit.rules.TemporaryFolder; | |
| public class Sha3HasherTest { | |
| @Rule | |
| public TemporaryFolder folder = new TemporaryFolder(); | |
| private static final String expected224 = "55d39d141deb65eb9f9363c348ed69d4b5c8e56afe9e1e75d7fd5f99"; | |
| private static final String expected256 = "865bf05cca7ba26fb8051e8366c6d19e21cadeebe3ee6bfa462b5c72275414ec"; | |
| private static final String expected384 = "71ced3eca3769907fc417bed3fdf82d9d7d36b99d89ead4caaa77d412ada4d37ec1ea26f857f0d964c2f2edb9cf03cf0"; | |
| private static final String expected512 = "b87fac887f393280be76c803f147a4938103bfc9d829281699a88e48ee54c9d3a7233b018a943a6b85ff5719e58fd0e34442bae8d2cafad54e7d18b7e60a3457"; | |
| @Test | |
| public void test512() throws Exception { | |
| Path file = folder.newFile().toPath(); | |
| Files.write(file, "the quick brown fox jumps over the lazy dog".getBytes(StandardCharsets.UTF_8)); | |
| assertThat(checksum512(file), is(expected512)); | |
| } | |
| } |
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