![David S. Miller](/assets/img/avatar_default.png)
This can cause packet buffer overflows in certain cases, the real bug will be fixed differently in a followon changeset. Signed-off-by: David S. Miller <davem@davemloft.net>
740 lines
21 KiB
C
740 lines
21 KiB
C
/*
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* ppp_mppe.c - interface MPPE to the PPP code.
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* This version is for use with Linux kernel 2.6.14+
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*
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* By Frank Cusack <fcusack@fcusack.com>.
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* Copyright (c) 2002,2003,2004 Google, Inc.
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* All rights reserved.
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*
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* License:
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* Permission to use, copy, modify, and distribute this software and its
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* documentation is hereby granted, provided that the above copyright
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* notice appears in all copies. This software is provided without any
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* warranty, express or implied.
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*
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* ALTERNATIVELY, provided that this notice is retained in full, this product
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* may be distributed under the terms of the GNU General Public License (GPL),
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* in which case the provisions of the GPL apply INSTEAD OF those given above.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*
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* Changelog:
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* 08/12/05 - Matt Domsch <Matt_Domsch@dell.com>
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* Only need extra skb padding on transmit, not receive.
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* 06/18/04 - Matt Domsch <Matt_Domsch@dell.com>, Oleg Makarenko <mole@quadra.ru>
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* Use Linux kernel 2.6 arc4 and sha1 routines rather than
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* providing our own.
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* 2/15/04 - TS: added #include <version.h> and testing for Kernel
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* version before using
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* MOD_DEC_USAGE_COUNT/MOD_INC_USAGE_COUNT which are
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* deprecated in 2.6
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*/
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/version.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/crypto.h>
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#include <linux/mm.h>
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#include <linux/ppp_defs.h>
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#include <linux/ppp-comp.h>
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#include <asm/scatterlist.h>
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#include "ppp_mppe.h"
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MODULE_AUTHOR("Frank Cusack <fcusack@fcusack.com>");
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MODULE_DESCRIPTION("Point-to-Point Protocol Microsoft Point-to-Point Encryption support");
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_ALIAS("ppp-compress-" __stringify(CI_MPPE));
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MODULE_VERSION("1.0.2");
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static unsigned int
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setup_sg(struct scatterlist *sg, const void *address, unsigned int length)
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{
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sg[0].page = virt_to_page(address);
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sg[0].offset = offset_in_page(address);
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sg[0].length = length;
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return length;
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}
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#define SHA1_PAD_SIZE 40
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/*
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* kernel crypto API needs its arguments to be in kmalloc'd memory, not in the module
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* static data area. That means sha_pad needs to be kmalloc'd.
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*/
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struct sha_pad {
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unsigned char sha_pad1[SHA1_PAD_SIZE];
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unsigned char sha_pad2[SHA1_PAD_SIZE];
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};
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static struct sha_pad *sha_pad;
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static inline void sha_pad_init(struct sha_pad *shapad)
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{
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memset(shapad->sha_pad1, 0x00, sizeof(shapad->sha_pad1));
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memset(shapad->sha_pad2, 0xF2, sizeof(shapad->sha_pad2));
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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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struct ppp_mppe_state {
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struct crypto_blkcipher *arc4;
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struct crypto_hash *sha1;
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unsigned char *sha1_digest;
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unsigned char master_key[MPPE_MAX_KEY_LEN];
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unsigned char session_key[MPPE_MAX_KEY_LEN];
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unsigned 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, */
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/* the unit has to change to bits */
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unsigned char bits; /* MPPE control bits */
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unsigned ccount; /* 12-bit coherency count (seqno) */
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unsigned stateful; /* stateful mode flag */
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int discard; /* stateful mode packet loss flag */
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int sanity_errors; /* take down LCP if too many */
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int unit;
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int debug;
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struct compstat stats;
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};
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/* struct ppp_mppe_state.bits definitions */
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#define MPPE_BIT_A 0x80 /* Encryption table were (re)inititalized */
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#define MPPE_BIT_B 0x40 /* MPPC only (not implemented) */
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#define MPPE_BIT_C 0x20 /* MPPC only (not implemented) */
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#define MPPE_BIT_D 0x10 /* This is an encrypted frame */
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#define MPPE_BIT_FLUSHED MPPE_BIT_A
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#define MPPE_BIT_ENCRYPTED MPPE_BIT_D
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#define MPPE_BITS(p) ((p)[4] & 0xf0)
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#define MPPE_CCOUNT(p) ((((p)[4] & 0x0f) << 8) + (p)[5])
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#define MPPE_CCOUNT_SPACE 0x1000 /* The size of the ccount space */
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#define MPPE_OVHD 2 /* MPPE overhead/packet */
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#define SANITY_MAX 1600 /* Max bogon factor we will tolerate */
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/*
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* Key Derivation, from RFC 3078, RFC 3079.
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* Equivalent to Get_Key() for MS-CHAP as described in RFC 3079.
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*/
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static void get_new_key_from_sha(struct ppp_mppe_state * state, unsigned char *InterimKey)
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{
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struct hash_desc desc;
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struct scatterlist sg[4];
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unsigned int nbytes;
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nbytes = setup_sg(&sg[0], state->master_key, state->keylen);
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nbytes += setup_sg(&sg[1], sha_pad->sha_pad1,
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sizeof(sha_pad->sha_pad1));
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nbytes += setup_sg(&sg[2], state->session_key, state->keylen);
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nbytes += setup_sg(&sg[3], sha_pad->sha_pad2,
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sizeof(sha_pad->sha_pad2));
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desc.tfm = state->sha1;
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desc.flags = 0;
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crypto_hash_digest(&desc, sg, nbytes, state->sha1_digest);
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memcpy(InterimKey, state->sha1_digest, state->keylen);
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}
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/*
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* Perform the MPPE rekey algorithm, from RFC 3078, sec. 7.3.
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* Well, not what's written there, but rather what they meant.
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*/
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static void mppe_rekey(struct ppp_mppe_state * state, int initial_key)
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{
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unsigned char InterimKey[MPPE_MAX_KEY_LEN];
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struct scatterlist sg_in[1], sg_out[1];
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struct blkcipher_desc desc = { .tfm = state->arc4 };
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get_new_key_from_sha(state, InterimKey);
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if (!initial_key) {
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crypto_blkcipher_setkey(state->arc4, InterimKey, state->keylen);
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setup_sg(sg_in, InterimKey, state->keylen);
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setup_sg(sg_out, state->session_key, state->keylen);
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if (crypto_blkcipher_encrypt(&desc, sg_out, sg_in,
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state->keylen) != 0) {
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printk(KERN_WARNING "mppe_rekey: cipher_encrypt failed\n");
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}
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} else {
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memcpy(state->session_key, InterimKey, state->keylen);
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}
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if (state->keylen == 8) {
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/* See RFC 3078 */
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state->session_key[0] = 0xd1;
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state->session_key[1] = 0x26;
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state->session_key[2] = 0x9e;
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}
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crypto_blkcipher_setkey(state->arc4, state->session_key, state->keylen);
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}
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/*
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* Allocate space for a (de)compressor.
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*/
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static void *mppe_alloc(unsigned char *options, int optlen)
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{
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struct ppp_mppe_state *state;
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unsigned int digestsize;
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if (optlen != CILEN_MPPE + sizeof(state->master_key)
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|| options[0] != CI_MPPE || options[1] != CILEN_MPPE)
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goto out;
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state = kmalloc(sizeof(*state), GFP_KERNEL);
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if (state == NULL)
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goto out;
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memset(state, 0, sizeof(*state));
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state->arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
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if (IS_ERR(state->arc4)) {
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state->arc4 = NULL;
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goto out_free;
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}
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state->sha1 = crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC);
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if (IS_ERR(state->sha1)) {
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state->sha1 = NULL;
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goto out_free;
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}
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digestsize = crypto_hash_digestsize(state->sha1);
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if (digestsize < MPPE_MAX_KEY_LEN)
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goto out_free;
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state->sha1_digest = kmalloc(digestsize, GFP_KERNEL);
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if (!state->sha1_digest)
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goto out_free;
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/* Save keys. */
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memcpy(state->master_key, &options[CILEN_MPPE],
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sizeof(state->master_key));
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memcpy(state->session_key, state->master_key,
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sizeof(state->master_key));
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/*
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* We defer initial key generation until mppe_init(), as mppe_alloc()
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* is called frequently during negotiation.
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*/
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return (void *)state;
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out_free:
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if (state->sha1_digest)
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kfree(state->sha1_digest);
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if (state->sha1)
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crypto_free_hash(state->sha1);
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if (state->arc4)
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crypto_free_blkcipher(state->arc4);
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kfree(state);
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out:
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return NULL;
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}
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/*
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* Deallocate space for a (de)compressor.
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*/
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static void mppe_free(void *arg)
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{
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
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if (state) {
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if (state->sha1_digest)
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kfree(state->sha1_digest);
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if (state->sha1)
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crypto_free_hash(state->sha1);
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if (state->arc4)
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crypto_free_blkcipher(state->arc4);
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kfree(state);
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}
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}
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/*
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* Initialize (de)compressor state.
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*/
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static int
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mppe_init(void *arg, unsigned char *options, int optlen, int unit, int debug,
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const char *debugstr)
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{
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
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unsigned char mppe_opts;
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if (optlen != CILEN_MPPE
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|| options[0] != CI_MPPE || options[1] != CILEN_MPPE)
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return 0;
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MPPE_CI_TO_OPTS(&options[2], mppe_opts);
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if (mppe_opts & MPPE_OPT_128)
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state->keylen = 16;
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else if (mppe_opts & MPPE_OPT_40)
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state->keylen = 8;
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else {
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printk(KERN_WARNING "%s[%d]: unknown key length\n", debugstr,
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unit);
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return 0;
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}
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if (mppe_opts & MPPE_OPT_STATEFUL)
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state->stateful = 1;
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/* Generate the initial session key. */
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mppe_rekey(state, 1);
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if (debug) {
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int i;
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char mkey[sizeof(state->master_key) * 2 + 1];
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char skey[sizeof(state->session_key) * 2 + 1];
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printk(KERN_DEBUG "%s[%d]: initialized with %d-bit %s mode\n",
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debugstr, unit, (state->keylen == 16) ? 128 : 40,
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(state->stateful) ? "stateful" : "stateless");
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for (i = 0; i < sizeof(state->master_key); i++)
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sprintf(mkey + i * 2, "%02x", state->master_key[i]);
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for (i = 0; i < sizeof(state->session_key); i++)
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sprintf(skey + i * 2, "%02x", state->session_key[i]);
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printk(KERN_DEBUG
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"%s[%d]: keys: master: %s initial session: %s\n",
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debugstr, unit, mkey, skey);
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}
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/*
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* Initialize the coherency count. The initial value is not specified
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* in RFC 3078, but we can make a reasonable assumption that it will
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* start at 0. Setting it to the max here makes the comp/decomp code
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* do the right thing (determined through experiment).
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*/
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state->ccount = MPPE_CCOUNT_SPACE - 1;
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/*
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* Note that even though we have initialized the key table, we don't
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* set the FLUSHED bit. This is contrary to RFC 3078, sec. 3.1.
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*/
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state->bits = MPPE_BIT_ENCRYPTED;
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state->unit = unit;
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state->debug = debug;
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return 1;
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}
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static int
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mppe_comp_init(void *arg, unsigned char *options, int optlen, int unit,
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int hdrlen, int debug)
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{
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/* ARGSUSED */
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return mppe_init(arg, options, optlen, unit, debug, "mppe_comp_init");
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}
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/*
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* We received a CCP Reset-Request (actually, we are sending a Reset-Ack),
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* tell the compressor to rekey. Note that we MUST NOT rekey for
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* every CCP Reset-Request; we only rekey on the next xmit packet.
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* We might get multiple CCP Reset-Requests if our CCP Reset-Ack is lost.
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* So, rekeying for every CCP Reset-Request is broken as the peer will not
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* know how many times we've rekeyed. (If we rekey and THEN get another
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* CCP Reset-Request, we must rekey again.)
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*/
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static void mppe_comp_reset(void *arg)
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{
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
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state->bits |= MPPE_BIT_FLUSHED;
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}
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/*
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* Compress (encrypt) a packet.
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* It's strange to call this a compressor, since the output is always
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* MPPE_OVHD + 2 bytes larger than the input.
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*/
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static int
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mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf,
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int isize, int osize)
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{
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
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struct blkcipher_desc desc = { .tfm = state->arc4 };
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int proto;
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struct scatterlist sg_in[1], sg_out[1];
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/*
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* Check that the protocol is in the range we handle.
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*/
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proto = PPP_PROTOCOL(ibuf);
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if (proto < 0x0021 || proto > 0x00fa)
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return 0;
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/* Make sure we have enough room to generate an encrypted packet. */
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if (osize < isize + MPPE_OVHD + 2) {
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/* Drop the packet if we should encrypt it, but can't. */
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printk(KERN_DEBUG "mppe_compress[%d]: osize too small! "
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"(have: %d need: %d)\n", state->unit,
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osize, osize + MPPE_OVHD + 2);
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return -1;
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}
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osize = isize + MPPE_OVHD + 2;
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/*
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* Copy over the PPP header and set control bits.
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*/
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obuf[0] = PPP_ADDRESS(ibuf);
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obuf[1] = PPP_CONTROL(ibuf);
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obuf[2] = PPP_COMP >> 8; /* isize + MPPE_OVHD + 1 */
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obuf[3] = PPP_COMP; /* isize + MPPE_OVHD + 2 */
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obuf += PPP_HDRLEN;
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state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
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if (state->debug >= 7)
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printk(KERN_DEBUG "mppe_compress[%d]: ccount %d\n", state->unit,
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state->ccount);
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obuf[0] = state->ccount >> 8;
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obuf[1] = state->ccount & 0xff;
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if (!state->stateful || /* stateless mode */
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((state->ccount & 0xff) == 0xff) || /* "flag" packet */
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(state->bits & MPPE_BIT_FLUSHED)) { /* CCP Reset-Request */
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/* We must rekey */
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if (state->debug && state->stateful)
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printk(KERN_DEBUG "mppe_compress[%d]: rekeying\n",
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state->unit);
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mppe_rekey(state, 0);
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state->bits |= MPPE_BIT_FLUSHED;
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}
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obuf[0] |= state->bits;
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state->bits &= ~MPPE_BIT_FLUSHED; /* reset for next xmit */
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obuf += MPPE_OVHD;
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ibuf += 2; /* skip to proto field */
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isize -= 2;
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/* Encrypt packet */
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setup_sg(sg_in, ibuf, isize);
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setup_sg(sg_out, obuf, osize);
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if (crypto_blkcipher_encrypt(&desc, sg_out, sg_in, isize) != 0) {
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printk(KERN_DEBUG "crypto_cypher_encrypt failed\n");
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return -1;
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}
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state->stats.unc_bytes += isize;
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state->stats.unc_packets++;
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state->stats.comp_bytes += osize;
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state->stats.comp_packets++;
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return osize;
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}
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/*
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* Since every frame grows by MPPE_OVHD + 2 bytes, this is always going
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* to look bad ... and the longer the link is up the worse it will get.
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*/
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static void mppe_comp_stats(void *arg, struct compstat *stats)
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{
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
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*stats = state->stats;
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}
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static int
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mppe_decomp_init(void *arg, unsigned char *options, int optlen, int unit,
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int hdrlen, int mru, int debug)
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{
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/* ARGSUSED */
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return mppe_init(arg, options, optlen, unit, debug, "mppe_decomp_init");
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}
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/*
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* We received a CCP Reset-Ack. Just ignore it.
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*/
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static void mppe_decomp_reset(void *arg)
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{
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/* ARGSUSED */
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return;
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}
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/*
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* Decompress (decrypt) an MPPE packet.
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*/
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static int
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mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
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int osize)
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{
|
|
struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
|
|
struct blkcipher_desc desc = { .tfm = state->arc4 };
|
|
unsigned ccount;
|
|
int flushed = MPPE_BITS(ibuf) & MPPE_BIT_FLUSHED;
|
|
int sanity = 0;
|
|
struct scatterlist sg_in[1], sg_out[1];
|
|
|
|
if (isize <= PPP_HDRLEN + MPPE_OVHD) {
|
|
if (state->debug)
|
|
printk(KERN_DEBUG
|
|
"mppe_decompress[%d]: short pkt (%d)\n",
|
|
state->unit, isize);
|
|
return DECOMP_ERROR;
|
|
}
|
|
|
|
/*
|
|
* Make sure we have enough room to decrypt the packet.
|
|
* Note that for our test we only subtract 1 byte whereas in
|
|
* mppe_compress() we added 2 bytes (+MPPE_OVHD);
|
|
* this is to account for possible PFC.
|
|
*/
|
|
if (osize < isize - MPPE_OVHD - 1) {
|
|
printk(KERN_DEBUG "mppe_decompress[%d]: osize too small! "
|
|
"(have: %d need: %d)\n", state->unit,
|
|
osize, isize - MPPE_OVHD - 1);
|
|
return DECOMP_ERROR;
|
|
}
|
|
osize = isize - MPPE_OVHD - 2; /* assume no PFC */
|
|
|
|
ccount = MPPE_CCOUNT(ibuf);
|
|
if (state->debug >= 7)
|
|
printk(KERN_DEBUG "mppe_decompress[%d]: ccount %d\n",
|
|
state->unit, ccount);
|
|
|
|
/* sanity checks -- terminate with extreme prejudice */
|
|
if (!(MPPE_BITS(ibuf) & MPPE_BIT_ENCRYPTED)) {
|
|
printk(KERN_DEBUG
|
|
"mppe_decompress[%d]: ENCRYPTED bit not set!\n",
|
|
state->unit);
|
|
state->sanity_errors += 100;
|
|
sanity = 1;
|
|
}
|
|
if (!state->stateful && !flushed) {
|
|
printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set in "
|
|
"stateless mode!\n", state->unit);
|
|
state->sanity_errors += 100;
|
|
sanity = 1;
|
|
}
|
|
if (state->stateful && ((ccount & 0xff) == 0xff) && !flushed) {
|
|
printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set on "
|
|
"flag packet!\n", state->unit);
|
|
state->sanity_errors += 100;
|
|
sanity = 1;
|
|
}
|
|
|
|
if (sanity) {
|
|
if (state->sanity_errors < SANITY_MAX)
|
|
return DECOMP_ERROR;
|
|
else
|
|
/*
|
|
* Take LCP down if the peer is sending too many bogons.
|
|
* We don't want to do this for a single or just a few
|
|
* instances since it could just be due to packet corruption.
|
|
*/
|
|
return DECOMP_FATALERROR;
|
|
}
|
|
|
|
/*
|
|
* Check the coherency count.
|
|
*/
|
|
|
|
if (!state->stateful) {
|
|
/* RFC 3078, sec 8.1. Rekey for every packet. */
|
|
while (state->ccount != ccount) {
|
|
mppe_rekey(state, 0);
|
|
state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
|
|
}
|
|
} else {
|
|
/* RFC 3078, sec 8.2. */
|
|
if (!state->discard) {
|
|
/* normal state */
|
|
state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
|
|
if (ccount != state->ccount) {
|
|
/*
|
|
* (ccount > state->ccount)
|
|
* Packet loss detected, enter the discard state.
|
|
* Signal the peer to rekey (by sending a CCP Reset-Request).
|
|
*/
|
|
state->discard = 1;
|
|
return DECOMP_ERROR;
|
|
}
|
|
} else {
|
|
/* discard state */
|
|
if (!flushed) {
|
|
/* ccp.c will be silent (no additional CCP Reset-Requests). */
|
|
return DECOMP_ERROR;
|
|
} else {
|
|
/* Rekey for every missed "flag" packet. */
|
|
while ((ccount & ~0xff) !=
|
|
(state->ccount & ~0xff)) {
|
|
mppe_rekey(state, 0);
|
|
state->ccount =
|
|
(state->ccount +
|
|
256) % MPPE_CCOUNT_SPACE;
|
|
}
|
|
|
|
/* reset */
|
|
state->discard = 0;
|
|
state->ccount = ccount;
|
|
/*
|
|
* Another problem with RFC 3078 here. It implies that the
|
|
* peer need not send a Reset-Ack packet. But RFC 1962
|
|
* requires it. Hopefully, M$ does send a Reset-Ack; even
|
|
* though it isn't required for MPPE synchronization, it is
|
|
* required to reset CCP state.
|
|
*/
|
|
}
|
|
}
|
|
if (flushed)
|
|
mppe_rekey(state, 0);
|
|
}
|
|
|
|
/*
|
|
* Fill in the first part of the PPP header. The protocol field
|
|
* comes from the decrypted data.
|
|
*/
|
|
obuf[0] = PPP_ADDRESS(ibuf); /* +1 */
|
|
obuf[1] = PPP_CONTROL(ibuf); /* +1 */
|
|
obuf += 2;
|
|
ibuf += PPP_HDRLEN + MPPE_OVHD;
|
|
isize -= PPP_HDRLEN + MPPE_OVHD; /* -6 */
|
|
/* net osize: isize-4 */
|
|
|
|
/*
|
|
* Decrypt the first byte in order to check if it is
|
|
* a compressed or uncompressed protocol field.
|
|
*/
|
|
setup_sg(sg_in, ibuf, 1);
|
|
setup_sg(sg_out, obuf, 1);
|
|
if (crypto_blkcipher_decrypt(&desc, sg_out, sg_in, 1) != 0) {
|
|
printk(KERN_DEBUG "crypto_cypher_decrypt failed\n");
|
|
return DECOMP_ERROR;
|
|
}
|
|
|
|
/*
|
|
* Do PFC decompression.
|
|
* This would be nicer if we were given the actual sk_buff
|
|
* instead of a char *.
|
|
*/
|
|
if ((obuf[0] & 0x01) != 0) {
|
|
obuf[1] = obuf[0];
|
|
obuf[0] = 0;
|
|
obuf++;
|
|
osize++;
|
|
}
|
|
|
|
/* And finally, decrypt the rest of the packet. */
|
|
setup_sg(sg_in, ibuf + 1, isize - 1);
|
|
setup_sg(sg_out, obuf + 1, osize - 1);
|
|
if (crypto_blkcipher_decrypt(&desc, sg_out, sg_in, isize - 1)) {
|
|
printk(KERN_DEBUG "crypto_cypher_decrypt failed\n");
|
|
return DECOMP_ERROR;
|
|
}
|
|
|
|
state->stats.unc_bytes += osize;
|
|
state->stats.unc_packets++;
|
|
state->stats.comp_bytes += isize;
|
|
state->stats.comp_packets++;
|
|
|
|
/* good packet credit */
|
|
state->sanity_errors >>= 1;
|
|
|
|
return osize;
|
|
}
|
|
|
|
/*
|
|
* Incompressible data has arrived (this should never happen!).
|
|
* We should probably drop the link if the protocol is in the range
|
|
* of what should be encrypted. At the least, we should drop this
|
|
* packet. (How to do this?)
|
|
*/
|
|
static void mppe_incomp(void *arg, unsigned char *ibuf, int icnt)
|
|
{
|
|
struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
|
|
|
|
if (state->debug &&
|
|
(PPP_PROTOCOL(ibuf) >= 0x0021 && PPP_PROTOCOL(ibuf) <= 0x00fa))
|
|
printk(KERN_DEBUG
|
|
"mppe_incomp[%d]: incompressible (unencrypted) data! "
|
|
"(proto %04x)\n", state->unit, PPP_PROTOCOL(ibuf));
|
|
|
|
state->stats.inc_bytes += icnt;
|
|
state->stats.inc_packets++;
|
|
state->stats.unc_bytes += icnt;
|
|
state->stats.unc_packets++;
|
|
}
|
|
|
|
/*************************************************************
|
|
* Module interface table
|
|
*************************************************************/
|
|
|
|
/*
|
|
* Procedures exported to if_ppp.c.
|
|
*/
|
|
static struct compressor ppp_mppe = {
|
|
.compress_proto = CI_MPPE,
|
|
.comp_alloc = mppe_alloc,
|
|
.comp_free = mppe_free,
|
|
.comp_init = mppe_comp_init,
|
|
.comp_reset = mppe_comp_reset,
|
|
.compress = mppe_compress,
|
|
.comp_stat = mppe_comp_stats,
|
|
.decomp_alloc = mppe_alloc,
|
|
.decomp_free = mppe_free,
|
|
.decomp_init = mppe_decomp_init,
|
|
.decomp_reset = mppe_decomp_reset,
|
|
.decompress = mppe_decompress,
|
|
.incomp = mppe_incomp,
|
|
.decomp_stat = mppe_comp_stats,
|
|
.owner = THIS_MODULE,
|
|
.comp_extra = MPPE_PAD,
|
|
};
|
|
|
|
/*
|
|
* ppp_mppe_init()
|
|
*
|
|
* Prior to allowing load, try to load the arc4 and sha1 crypto
|
|
* libraries. The actual use will be allocated later, but
|
|
* this way the module will fail to insmod if they aren't available.
|
|
*/
|
|
|
|
static int __init ppp_mppe_init(void)
|
|
{
|
|
int answer;
|
|
if (!(crypto_has_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC) &&
|
|
crypto_has_hash("sha1", 0, CRYPTO_ALG_ASYNC)))
|
|
return -ENODEV;
|
|
|
|
sha_pad = kmalloc(sizeof(struct sha_pad), GFP_KERNEL);
|
|
if (!sha_pad)
|
|
return -ENOMEM;
|
|
sha_pad_init(sha_pad);
|
|
|
|
answer = ppp_register_compressor(&ppp_mppe);
|
|
|
|
if (answer == 0)
|
|
printk(KERN_INFO "PPP MPPE Compression module registered\n");
|
|
else
|
|
kfree(sha_pad);
|
|
|
|
return answer;
|
|
}
|
|
|
|
static void __exit ppp_mppe_cleanup(void)
|
|
{
|
|
ppp_unregister_compressor(&ppp_mppe);
|
|
kfree(sha_pad);
|
|
}
|
|
|
|
module_init(ppp_mppe_init);
|
|
module_exit(ppp_mppe_cleanup);
|