NAME
- auth - authentication using station-to-station protocol
DESCRIPTION
-
The following protocol,
based on the Station-to-Station
protocol, is used for mutual authentication of two parties,
each possessing a certificate from the same certifying authority (CA).
In the description below:
- alpha
- is a Diffie-Hellman base used system wide
- p
- is a Diffie-Hellman modulus used system wide
- Rx
- is a random number of the same order as
p.
- PKx
- the public key of
x
- SKx
- the private key of
x
- CERTx
- the public key
of
x
signed by the certifying authority
- sign(x)
- represents x signed with n's private key
In the following, the parties are labelled 0 and 1.
Each sends its public key and certificate to the other together with a computation alpha**r0 mod p (alpha**r1 mod p) based on the Diffie-Hellman parameters contained in the certificate:
0 -> 1 alpha**r0 mod p, CERTu0, PKu0 1 -> 0 alpha**r1 mod p, CERTu1, PKu1
Each can now use the CA's public key and the certificate received to check that each has the other's public key.
Finally, each user signs values known to both that each can then verify:
0 -> 1 sig0(alpha**r0 mod p, alpha**r1 mod p) 1 -> 0 sig1(alpha**r0 mod p, alpha**r1 mod p)
At this point 0 and 1 can calculate the shared secret alpha**(r0*r1), and can use it to encrypt later communications.
SEE ALSO
- keyring-auth(2), keytext(6), login(6)
| AUTH(6) | Rev: Tue Jan 29 13:11:50 GMT 2008 |