Add SRA authentication to src/crypto/telnet.

SRA does a Diffie-Hellmen exchange and then DES-encrypts the
authentication data. If the authentication is successful, it also
sets up a session key for DES encryption.

SRA was originally developed at Texas A&M University.

This code is probably export restricted (despite the fact that I
originally found it at a University in Germany).

SRA is not perfect. It is vulnerable to monkey-in-the-middle attacks
and does not use tremendously large DH constants (and thus an individual
exchange probably could be factored in a few days on modern CPU
horsepower). It does not, however, require any changes in user or
administrative behavior and foils session hijacking and sniffing.
The goal of this commit is that telnet and telnetd end up in the DES
distribution and that therefore an encrypted session telnet becomes
standard issue for FreeBSD.

1 files changed, 3 insertions, 2 deletions

diff --git a/contrib/telnet/arpa/telnet.h b/contrib/telnet/arpa/telnet.h
index 01601f1..8a17ff1 100644
--- a/contrib/telnet/arpa/telnet.h
+++ b/contrib/telnet/arpa/telnet.h
@@ -280,13 +280,14 @@ extern char *slc_names[];
 #define	AUTHTYPE_KERBEROS_V5	2
 #define	AUTHTYPE_SPX		3
 #define	AUTHTYPE_MINK		4
-#define	AUTHTYPE_CNT		5
+#define AUTHTYPE_SRA		6
+#define	AUTHTYPE_CNT		7
 
 #define	AUTHTYPE_TEST		99
 
 #ifdef	AUTH_NAMES
 char *authtype_names[] = {
-	"NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
+	"NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", NULL, "SRA",
 	0
 };
 #else