[PPP]: add PPP MPPE encryption module

From: Matt Domsch <Matt_Domsch@dell.com>

The patch below implements the Microsoft Point-to-Point Encryption method
as a PPP compressor/decompressor.  This is necessary for Linux clients and
servers to interoperate with Microsoft Point-to-Point Tunneling Protocol
(PPTP) servers (either Microsoft PPTP servers or the poptop project) which
use MPPE to encrypt data when creating a VPN.

This patch differs from the kernel_ppp_mppe DKMS pacakge at
pptpclient.sourceforge.net by utilizing the kernel crypto routines rather
than providing its own SHA1 and arcfour implementations.

Minor changes to ppp_generic.c try to prevent a link from disabling
compression (in our case, the encryption) after it has started using
compression (encryption).

Feedback to <pptpclient-devel@lists.sourceforge.net> please.

Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Cc: James Cameron <james.cameron@hp.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Matt Domsch 2005-11-08 09:40:47 -08:00 committed by David S. Miller
parent 6722e78c90
commit b3f9b92a6e
7 changed files with 902 additions and 26 deletions

View file

@ -111,6 +111,8 @@ struct compressor {
/* Used in locking compressor modules */
struct module *owner;
/* Extra skb space needed by the compressor algorithm */
unsigned int comp_extra;
};
/*
@ -190,6 +192,13 @@ struct compressor {
#define DEFLATE_MAKE_OPT(w) ((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
#define DEFLATE_CHK_SEQUENCE 0
/*
* Definitions for MPPE.
*/
#define CI_MPPE 18 /* config option for MPPE */
#define CILEN_MPPE 6 /* length of config option */
/*
* Definitions for other, as yet unsupported, compression methods.
*/