adding documentation/analysis of key format

sshkeys/const.go

@@ -1,21 +1,12 @@
 package sshkeys
 
-// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key
-
+// Needed for V1 key format.
 const (
-	AuthMagic string = "openssh-key-v1"
+	KeyV1Magic string = "openssh-key-v1"
 )
 
-type EncryptedSSHKey2 struct {
-	SSHKey2
-	Salt string
-	Rounds uint32
-}
-type SSHKey2 struct {
-	CipherName string
-	KDFName    string
-	KDFOpts    string
-	NumKeys    int
-	Keys       []string
-	Encrypted  []string
-}
+// Key cipher names.
+const (
+	CipherED25519 = iota
+	CipherRSA     = iota
+)