Package com.Ostermiller.util

Class MD5InputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
com.Ostermiller.util.MD5InputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public class MD5InputStream extends FilterInputStream
Implements MD5 functionality on a stream. More information about this class is available from ostermiller.org.

This class produces a 128-bit "fingerprint" or "message digest" for all data read from this stream. It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given pre-specified target message digest. The MD5 algorithm is intended for digital signature applications, where a large file must be "compressed" in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA.

For more information see RFC1321.

Since:
ostermillerutils 1.00.00
Author:
Santeri Paavolainen http://santtu.iki.fi/programs/md5/, Stephen Ostermiller https://ostermiller.org/contact.pl?regarding=Java+Utilities
See Also:

  • Constructor Details

    • MD5InputStream

      public MD5InputStream(InputStream in)
      Creates a MD5InputStream
      Parameters:
      in - the underlying input stream

  • Method Details

    • read

      public int read() throws IOException
      Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

      This method simply performs in.read() and returns the result.

      Overrides:
      read in class FilterInputStream
      Returns:
      the next byte of data, or -1 if the end of the stream is reached.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      ostermillerutils 1.00.00

    • read

      public int read(byte[] bytes, int offset, int length) throws IOException
      Reads up to length bytes of data from this input stream into an array of bytes. This method blocks until some input is available.
      Overrides:
      read in class FilterInputStream
      Parameters:
      bytes - the buffer into which the data is read.
      offset - the start offset of the data.
      length - the maximum number of bytes read.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      ostermillerutils 1.00.00

    • getHash

      public byte[] getHash()
      Returns array of bytes representing hash of the stream so far.
      Returns:
      Array of 16 bytes, the hash of all read bytes.
      Since:
      ostermillerutils 1.00.00

    • getHashString

      public String getHashString()
      Get a 32-character hex representation representing hash of the stream so far.
      Returns:
      A string containing the hash of all written bytes.
      Since:
      ostermillerutils 1.00.00