New in release 1.3:
- bug fixex.
- The files SSHDSAHostskeys.Text and SSHRSAHostkeys.Text
got merged to SSHHostkeys.Text.
- New module cryptPrimes.Mod for generating large safe prime
numbers.
- Module cryptDSA is finished (includes signing now).
- Improved performance.
I've tuned the performace of multi pecision integers
(cryptBigNumbers.Mod). The time for establishing a SSH-
connection, which is mainlly determined by the computation
of '(a^p) mod m' in the Diffie Hellman key exchange, could be
reduced by a factor of nearly three but is still more than
two times greater than with the original SSH.
This was the first time I really missed unsigned integer types
in the Oberon language. In the old implementation of
cryptBigNumbers multi precision integers had been represented
by 8 bit digits because of ease of coding (no overflow- and sign
problems when computing the values in LONGINT). In the
new implementation the 'digits' are 32 bit. Unfortunateley
a lot of the benefit of using larger digits gets lost by the
additional effort for treating the sign bit and overflow
conditions. With the availability of the Modula2 CARDINAL
type (and CARDINAL64) coding would have been much easier
and (still more important) the code would have been faster.