com.jcraft.jsch

Interface HASH

public interface HASH

Usually not to be used by applications. The interface for a (cryptographic) Hash algorithm.

This is a slimmed-down version of MessageDigest.

Several parts of the library will look up the implementation class to use in the configuration and then instantiate it using the no-argument constructor. The used algorithm names are only "md5" and "sha-1", for now.

The library includes default implementations of MD5 and SHA-1 based on Java's MessageDigest.

Method Summary

Modifier and Type	Method and Description
byte[]	digest() calculates and returns the digest for all the data hashed up so far.
int	getBlockSize() returns the size of the hash which will be produced from input.
void	init() initializes the algorithm for new input data.
void	update(byte[] foo, int start, int len) Updates the algorithm with new data.

Method Detail

init

void init()
   throws Exception

initializes the algorithm for new input data. This will be called before the first call to update(byte[], int, int).

Throws:

Exception

getBlockSize

int getBlockSize()

returns the size of the hash which will be produced from input. This usually will be a constant function, like 16 for MD5 and 20 for SHA1.

Returns:

the length of the produced hash, in bytes.

See Also:

MessageDigest.getDigestLength()

update

void update(byte[] foo,
            int start,
            int len)
     throws Exception

Updates the algorithm with new data. The data will not be changed, only our internal state.

Parameters:

foo - an array containing new data to hash.

start - the index of the start of the data in foo.

len - the length of the new added data.

Throws:

Exception

See Also:

MessageDigest.update()

digest

byte[] digest()
       throws Exception

calculates and returns the digest for all the data hashed up so far.

Returns:

an array containing the hash. This will have length getBlockSize().

Throws:

Exception

See Also:

MessageDigest.digest()