Add fixed string and nonce to prop 176 at suggestion from agl

   cell.  If AuthType is 1 (meaning "RSA-SHA256-TLSSecret"), then the

   Authentication contains the following:

       Type: The characters "AUTH0001" [8 octets]

       CID: A SHA256 hash of the client's RSA1024 identity key [32 octets]

       SID: A SHA256 hash of the server's RSA1024 identity key [32 octets]

       SLOG: A SHA256 hash of all bytes sent from the server to the client

         as part of the negotiation up to and including the

         AUTH_CHALLENGE cell; that is, the VERSIONS cell,

         the CERT cell, and the AUTH_CHALLENGE cell. [32 octets]

       CLOG: A SHA256 hash of all byte sent from the client to the

       CLOG: A SHA256 hash of all bytes sent from the client to the

         server as part of the negotiation so far; that is, the

         VERSIONS cell and the CERT cell. [32 octets]

       SCERT: A SHA256 hash of the server's TLS link

             "Tor V3 handshake TLS cross-certification"

          [32 octets]

       TIME: The time of day in seconds since the POSIX epoch. [8 octets]

       NONCE: A 16 byte value, randomly chosen by the client [16 octets]

       SIG: A signature of a SHA256 hash of all the previous fields

         using the client's "Authenticate" key as presented.  (As

         always in Tor, we use OAEP-MGF1 padding; see tor-spec.txt