/* * 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 * ". * * 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" #ifdef __cplusplus extern "C" { #endif #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); #ifdef __cplusplus } #endif #endif /* MPPE_H */ #endif /* PPP_SUPPORT && MPPE_SUPPORT */