tempfork: temporarily fork gliderlabs/ssh and x/crypto/ssh

While we rearrange/upstream things.

gliderlabs/ssh is forked into tempfork from our prior fork
at https://github.com/tailscale/ssh/commit/be8b7add4057ef5a8e458b42331a7633c06d026a

x/crypto/ssh OTOH is forked at
https://github.com/tailscale/golang-x-crypto because it was gnarlier
to vendor with various internal packages, etc.
Its git history shows where it starts (2c7772ba30643b7a2026cbea938420dce7c6384d).

Updates #3802

Change-Id: I546e5cdf831cfc030a6c42557c0ad2c58766c65f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

tempfork/gliderlabs/ssh/example_test.go

@@ -0,0 +1,40 @@
+package ssh_test
+
+import (
+	"io"
+	"io/ioutil"
+
+	"tailscale.com/tempfork/gliderlabs/ssh"
+)
+
+func ExampleListenAndServe() {
+	ssh.ListenAndServe(":2222", func(s ssh.Session) {
+		io.WriteString(s, "Hello world\n")
+	})
+}
+
+func ExamplePasswordAuth() {
+	ssh.ListenAndServe(":2222", nil,
+		ssh.PasswordAuth(func(ctx ssh.Context, pass string) bool {
+			return pass == "secret"
+		}),
+	)
+}
+
+func ExampleNoPty() {
+	ssh.ListenAndServe(":2222", nil, ssh.NoPty())
+}
+
+func ExamplePublicKeyAuth() {
+	ssh.ListenAndServe(":2222", nil,
+		ssh.PublicKeyAuth(func(ctx ssh.Context, key ssh.PublicKey) bool {
+			data, _ := ioutil.ReadFile("/path/to/allowed/key.pub")
+			allowed, _, _, _, _ := ssh.ParseAuthorizedKey(data)
+			return ssh.KeysEqual(key, allowed)
+		}),
+	)
+}
+
+func ExampleHostKeyFile() {
+	ssh.ListenAndServe(":2222", nil, ssh.HostKeyFile("/path/to/host/key"))
+}