Add ssh instructions, log host key

cmd/ssh/README.md

@@ -0,0 +1,34 @@
+# URDT-USSD SSH server
+
+An SSH server entry point for the vise engine.
+
+
+## Adding public keys for access
+
+Map your (client) public key to a session identifier (e.g. phone number)
+
+```
+go run -v -tags logtrace ./cmd/ssh/sshkey/main.go -i <session_id> [--dbdir <dbpath>] <publickey_filepath>
+```
+
+
+## Create a private key for the server
+
+```
+ssh-keygen -N "" -f <privatekey_filepath>
+```
+
+
+## Run the server
+
+
+```
+go run -v -tags logtrace ./cmd/ssh/main.go -h <host> -p <port> [--dbdir <dbpath>] <privatekey_filepath>
+```
+
+
+## Connect to the server
+
+```
+ssh -T -p <port> <host>
+```

internal/ssh/ssh.go

@@ -3,6 +3,7 @@ package ssh
 import (
 	"context"
 	"encoding/hex"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"net"
@@ -222,6 +223,9 @@ func(s *SshRunner) Run(ctx context.Context, keyStore *SshKeyStore) {
 	if err != nil {
 		logg.ErrorCtxf(ctx, "Failed to parse private key", "err", err)
 	}
+	srvPub := private.PublicKey()
+	srvPubStr := base64.StdEncoding.EncodeToString(srvPub.Marshal())
+	logg.InfoCtxf(ctx, "have server key", "type", srvPub.Type(), "public", srvPubStr)
 	cfg.AddHostKey(private)
 
 	s.lst, err = net.Listen("tcp", fmt.Sprintf("%s:%d", s.Host, s.Port))