178 lines
6.1 KiB
C
178 lines
6.1 KiB
C
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/*
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* mppe.h - Definitions for MPPE
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*
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* Copyright (c) 2008 Paul Mackerras. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* 3. The name(s) of the authors of this software must not be used to
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* endorse or promote products derived from this software without
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* prior written permission.
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*
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* 4. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by Paul Mackerras
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* <paulus@samba.org>".
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*
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* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
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* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
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* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
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* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
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* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "lwip/opt.h"
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#if PPP_SUPPORT && MPPE_SUPPORT /* don't build if not configured for use in lwipopts.h */
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#ifndef MPPE_H
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#define MPPE_H
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#if LWIP_INCLUDED_POLARSSL_ARC4
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#include "netif/ppp/polarssl/arc4.h"
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#else
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#include "polarssl/arc4.h"
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#endif
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#define MPPE_PAD 4 /* MPPE growth per frame */
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#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */
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/* option bits for ccp_options.mppe */
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#define MPPE_OPT_40 0x01 /* 40 bit */
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#define MPPE_OPT_128 0x02 /* 128 bit */
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#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */
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/* unsupported opts */
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#define MPPE_OPT_56 0x08 /* 56 bit */
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#define MPPE_OPT_MPPC 0x10 /* MPPC compression */
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#define MPPE_OPT_D 0x20 /* Unknown */
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#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)
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#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */
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/*
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* This is not nice ... the alternative is a bitfield struct though.
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* And unfortunately, we cannot share the same bits for the option
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* names above since C and H are the same bit. We could do a u_int32
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* but then we have to do a htonl() all the time and/or we still need
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* to know which octet is which.
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*/
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#define MPPE_C_BIT 0x01 /* MPPC */
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#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */
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#define MPPE_L_BIT 0x20 /* 40-bit */
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#define MPPE_S_BIT 0x40 /* 128-bit */
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#define MPPE_M_BIT 0x80 /* 56-bit, not supported */
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#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */
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/* Does not include H bit; used for least significant octet only. */
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#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)
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/* Build a CI from mppe opts (see RFC 3078) */
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#define MPPE_OPTS_TO_CI(opts, ci) \
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do { \
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u_char *ptr = ci; /* u_char[4] */ \
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\
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/* H bit */ \
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if (opts & MPPE_OPT_STATEFUL) \
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*ptr++ = 0x0; \
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else \
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*ptr++ = MPPE_H_BIT; \
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*ptr++ = 0; \
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*ptr++ = 0; \
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\
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/* S,L bits */ \
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*ptr = 0; \
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if (opts & MPPE_OPT_128) \
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*ptr |= MPPE_S_BIT; \
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if (opts & MPPE_OPT_40) \
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*ptr |= MPPE_L_BIT; \
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/* M,D,C bits not supported */ \
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} while (/* CONSTCOND */ 0)
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/* The reverse of the above */
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#define MPPE_CI_TO_OPTS(ci, opts) \
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do { \
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const u_char *ptr = ci; /* u_char[4] */ \
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\
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opts = 0; \
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\
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/* H bit */ \
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if (!(ptr[0] & MPPE_H_BIT)) \
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opts |= MPPE_OPT_STATEFUL; \
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\
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/* S,L bits */ \
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if (ptr[3] & MPPE_S_BIT) \
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opts |= MPPE_OPT_128; \
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if (ptr[3] & MPPE_L_BIT) \
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opts |= MPPE_OPT_40; \
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\
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/* M,D,C bits */ \
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if (ptr[3] & MPPE_M_BIT) \
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opts |= MPPE_OPT_56; \
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if (ptr[3] & MPPE_D_BIT) \
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opts |= MPPE_OPT_D; \
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if (ptr[3] & MPPE_C_BIT) \
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opts |= MPPE_OPT_MPPC; \
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\
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/* Other bits */ \
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if (ptr[0] & ~MPPE_H_BIT) \
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opts |= MPPE_OPT_UNKNOWN; \
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if (ptr[1] || ptr[2]) \
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opts |= MPPE_OPT_UNKNOWN; \
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if (ptr[3] & ~MPPE_ALL_BITS) \
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opts |= MPPE_OPT_UNKNOWN; \
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} while (/* CONSTCOND */ 0)
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/* Shared MPPE padding between MSCHAP and MPPE */
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#define SHA1_PAD_SIZE 40
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static const u8_t mppe_sha1_pad1[SHA1_PAD_SIZE] = {
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
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};
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static const u8_t mppe_sha1_pad2[SHA1_PAD_SIZE] = {
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0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
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0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
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0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
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0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2
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};
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/*
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* State for an MPPE (de)compressor.
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*/
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typedef struct ppp_mppe_state {
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arc4_context arc4;
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u8_t master_key[MPPE_MAX_KEY_LEN];
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u8_t session_key[MPPE_MAX_KEY_LEN];
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u8_t keylen; /* key length in bytes */
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/* NB: 128-bit == 16, 40-bit == 8!
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* If we want to support 56-bit, the unit has to change to bits
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*/
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u8_t bits; /* MPPE control bits */
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u16_t ccount; /* 12-bit coherency count (seqno) */
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u16_t sanity_errors; /* take down LCP if too many */
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unsigned int stateful :1; /* stateful mode flag */
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unsigned int discard :1; /* stateful mode packet loss flag */
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} ppp_mppe_state;
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void mppe_set_key(ppp_pcb *pcb, ppp_mppe_state *state, u8_t *key);
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void mppe_init(ppp_pcb *pcb, ppp_mppe_state *state, u8_t options);
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void mppe_comp_reset(ppp_pcb *pcb, ppp_mppe_state *state);
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err_t mppe_compress(ppp_pcb *pcb, ppp_mppe_state *state, struct pbuf **pb, u16_t protocol);
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void mppe_decomp_reset(ppp_pcb *pcb, ppp_mppe_state *state);
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err_t mppe_decompress(ppp_pcb *pcb, ppp_mppe_state *state, struct pbuf **pb);
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#endif /* MPPE_H */
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#endif /* PPP_SUPPORT && MPPE_SUPPORT */
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