From: Andrew Sun (as000004@home.com) Subject: Success! pppd -> win98 with ms-chap authentication Newsgroups: comp.protocols.ppp, comp.os.linux.networking Date: 2000/05/23 Hello everyone, Windows 98 only accepts and validates the ms-chap response portion that's based on the LAN Manager password hash. By default, pppd only generates the part of the ms-chap response based on the NT password hash. As it turns out, the pppd code for ms-chap already includes the provision for generating the lanman hash response (now that saved a lot of work). -> Recompile pppd and include the -DMSLANMAN compile option. Note that I've tested this with pppd 2.3.5 on a SunOS system. Hopefully, the mslanman code remains intact in later pppd releases. The resulting pppd log, for a successful direct cable connection to win98, no password protection, should resemble the following: May 22 20:14:44 sun3-1 pppd[476]: pppd 2.3.5 started by asun, uid 2001 May 22 20:14:48 sun3-1 pppd[476]: Serial connection established. May 22 20:14:49 sun3-1 pppd[476]: Using interface ppp0 May 22 20:14:49 sun3-1 pppd[476]: Connect: ppp0 <--> /dev/cua May 22 20:14:51 sun3-1 pppd[476]: sent [LCP ConfAck id=0x3 ] May 22 20:14:51 sun3-1 pppd[476]: rcvd [CHAP Challenge id=0x1 , name = ""] May 22 20:14:51 sun3-1 pppd[476]: sent [CHAP Response id=0x1 , name = "win98nullpass"] May 22 20:14:51 sun3-1 pppd[476]: rcvd [CHAP Success id=0x1 ""] May 22 20:14:51 sun3-1 pppd[476]: sent [IPCP ConfReq id=0x1 ] $ ./testchap 00000000000000000000000000000000 hello Response length is 49, response is: C9 CA EE 9B 1C A7 87 04 79 36 8C 55 AB 88 EC 5A 57 E9 A1 B7 95 40 C3 74 F4 D9 9D AF 82 64 DC 3C 53 F9 BC 92 14 B5 5D 9E 78 C4 21 48 9D B7 A8 B4 01 $ If the "CHAP Response" above, or the testchap utility, shows a block of leading zeros, then the mslanman code isn't compiled into pppd. A summary of Win98 PPP server authentication behaviors are as follows: . Direct Cable Connection (DCC), Host mode, no password protection Pppd authenticates with ms-chap, any user name, and blank password. . DCC, Host mode, password protected Pppd authenticates with ms-chap, any user name, and set password. . Dial-Up Server pppd authenticates with ms-chap or PAP, any user name, and set password. If "Require Encrypted Password" is set, then PAP would be disallowed. And some other important notes to help Direct Cable Connection users. The serial port fixed speed is 19200. The PPP client must send the string CLIENT and receive the response CLIENTSERVER before PPP communications begin. As a PPP server, Win98 assigns IP 192.168.55.1 to itself, and assigns IP 192.168.55.2 to the peer. And finally, an excerpt from rfc2433, written by Microsoft: that use of the LAN Manager compatible challenge response has been deprecated; peers SHOULD NOT generate it, and the sub-field SHOULD be zero-filled. The algorithm used in the generation of the LAN Manager compatible challenge response is described here for informational purposes only.