BadVPN – Rev 1
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/*
* mppe.h - Definitions for MPPE
*
* Copyright (c) 2008 Paul Mackerras. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <paulus@samba.org>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && MPPE_SUPPORT /* don't build if not configured for use in lwipopts.h */
#ifndef MPPE_H
#define MPPE_H
#include "netif/ppp/pppcrypt.h"
#define MPPE_PAD 4 /* MPPE growth per frame */
#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */
/* option bits for ccp_options.mppe */
#define MPPE_OPT_40 0x01 /* 40 bit */
#define MPPE_OPT_128 0x02 /* 128 bit */
#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */
/* unsupported opts */
#define MPPE_OPT_56 0x08 /* 56 bit */
#define MPPE_OPT_MPPC 0x10 /* MPPC compression */
#define MPPE_OPT_D 0x20 /* Unknown */
#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)
#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */
/*
* This is not nice ... the alternative is a bitfield struct though.
* And unfortunately, we cannot share the same bits for the option
* names above since C and H are the same bit. We could do a u_int32
* but then we have to do a lwip_htonl() all the time and/or we still need
* to know which octet is which.
*/
#define MPPE_C_BIT 0x01 /* MPPC */
#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */
#define MPPE_L_BIT 0x20 /* 40-bit */
#define MPPE_S_BIT 0x40 /* 128-bit */
#define MPPE_M_BIT 0x80 /* 56-bit, not supported */
#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */
/* Does not include H bit; used for least significant octet only. */
#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)
/* Build a CI from mppe opts (see RFC 3078) */
#define MPPE_OPTS_TO_CI(opts, ci) \
do { \
u_char *ptr = ci; /* u_char[4] */ \
\
/* H bit */ \
if (opts & MPPE_OPT_STATEFUL) \
*ptr++ = 0x0; \
else \
*ptr++ = MPPE_H_BIT; \
*ptr++ = 0; \
*ptr++ = 0; \
\
/* S,L bits */ \
*ptr = 0; \
if (opts & MPPE_OPT_128) \
*ptr |= MPPE_S_BIT; \
if (opts & MPPE_OPT_40) \
*ptr |= MPPE_L_BIT; \
/* M,D,C bits not supported */ \
} while (/* CONSTCOND */ 0)
/* The reverse of the above */
#define MPPE_CI_TO_OPTS(ci, opts) \
do { \
const u_char *ptr = ci; /* u_char[4] */ \
\
opts = 0; \
\
/* H bit */ \
if (!(ptr[0] & MPPE_H_BIT)) \
opts |= MPPE_OPT_STATEFUL; \
\
/* S,L bits */ \
if (ptr[3] & MPPE_S_BIT) \
opts |= MPPE_OPT_128; \
if (ptr[3] & MPPE_L_BIT) \
opts |= MPPE_OPT_40; \
\
/* M,D,C bits */ \
if (ptr[3] & MPPE_M_BIT) \
opts |= MPPE_OPT_56; \
if (ptr[3] & MPPE_D_BIT) \
opts |= MPPE_OPT_D; \
if (ptr[3] & MPPE_C_BIT) \
opts |= MPPE_OPT_MPPC; \
\
/* Other bits */ \
if (ptr[0] & ~MPPE_H_BIT) \
opts |= MPPE_OPT_UNKNOWN; \
if (ptr[1] || ptr[2]) \
opts |= MPPE_OPT_UNKNOWN; \
if (ptr[3] & ~MPPE_ALL_BITS) \
opts |= MPPE_OPT_UNKNOWN; \
} while (/* CONSTCOND */ 0)
/* Shared MPPE padding between MSCHAP and MPPE */
#define SHA1_PAD_SIZE 40
static const u8_t mppe_sha1_pad1[SHA1_PAD_SIZE] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
static const u8_t mppe_sha1_pad2[SHA1_PAD_SIZE] = {
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2
};
/*
* State for an MPPE (de)compressor.
*/
typedef struct ppp_mppe_state {
lwip_arc4_context arc4;
u8_t master_key[MPPE_MAX_KEY_LEN];
u8_t session_key[MPPE_MAX_KEY_LEN];
u8_t keylen; /* key length in bytes */
/* NB: 128-bit == 16, 40-bit == 8!
* If we want to support 56-bit, the unit has to change to bits
*/
u8_t bits; /* MPPE control bits */
u16_t ccount; /* 12-bit coherency count (seqno) */
u16_t sanity_errors; /* take down LCP if too many */
unsigned int stateful :1; /* stateful mode flag */
unsigned int discard :1; /* stateful mode packet loss flag */
} ppp_mppe_state;
void mppe_set_key(ppp_pcb *pcb, ppp_mppe_state *state, u8_t *key);
void mppe_init(ppp_pcb *pcb, ppp_mppe_state *state, u8_t options);
void mppe_comp_reset(ppp_pcb *pcb, ppp_mppe_state *state);
err_t mppe_compress(ppp_pcb *pcb, ppp_mppe_state *state, struct pbuf **pb, u16_t protocol);
void mppe_decomp_reset(ppp_pcb *pcb, ppp_mppe_state *state);
err_t mppe_decompress(ppp_pcb *pcb, ppp_mppe_state *state, struct pbuf **pb);
#endif /* MPPE_H */
#endif /* PPP_SUPPORT && MPPE_SUPPORT */