This interface contains :
- a set of constant values, H0-H4, defined in "SECURE HASH STANDARD", FIPS PUB 180-2 ;
- implementation constant values to use in classes using SHA-1 algorithm.
This class extends the MessageDigestSpi class implementing all its abstract methods;
it overrides the "Object clone()" and "int engineGetDigestLength()" methods.
The auxiliary class providing means to process ASN1Sequence of three Integers.
Such sequences are parts of ASN1 encoded formats for DSA private and public keys.