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PPP, MPPE, using our ARC4 instead of Linux crypto ARC4

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This commit is contained in:
Sylvain Rochet 2015-03-29 01:04:02 +01:00
parent d5667343cb
commit 7ea8a754c1
1 changed files with 19 additions and 54 deletions
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73
src/netif/ppp/mppe.c
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@ -26,6 +26,8 @@
#include "lwip/opt.h"
#if PPP_SUPPORT && MPPE_SUPPORT /* don't build if not configured for use in lwipopts.h */
#include <string.h>
#include "lwip/err.h"
#include "netif/ppp/ppp_impl.h"
@ -39,6 +41,12 @@
#include "polarssl/sha1.h"
#endif
#if LWIP_INCLUDED_POLARSSL_ARC4
#include "netif/ppp/polarssl/arc4.h"
#else
#include "polarssl/arc4.h"
#endif
#define SHA1_SIGNATURE_SIZE 20
static unsigned int
@ -71,7 +79,7 @@ static inline void sha_pad_init(struct sha_pad *shapad)
* State for an MPPE (de)compressor.
*/
struct ppp_mppe_state {
struct crypto_blkcipher *arc4;
arc4_context arc4;
u8_t sha1_digest[SHA1_SIGNATURE_SIZE];
unsigned char master_key[MPPE_MAX_KEY_LEN];
unsigned char session_key[MPPE_MAX_KEY_LEN];
@ -127,21 +135,11 @@ static void get_new_key_from_sha(struct ppp_mppe_state * state)
*/
static void mppe_rekey(struct ppp_mppe_state * state, int initial_key)
{
struct scatterlist sg_in[1], sg_out[1];
struct blkcipher_desc desc = { .tfm = state->arc4 };
get_new_key_from_sha(state);
if (!initial_key) {
crypto_blkcipher_setkey(state->arc4, state->sha1_digest,
state->keylen);
sg_init_table(sg_in, 1);
sg_init_table(sg_out, 1);
setup_sg(sg_in, state->sha1_digest, state->keylen);
setup_sg(sg_out, state->session_key, state->keylen);
if (crypto_blkcipher_encrypt(&desc, sg_out, sg_in,
state->keylen) != 0) {
PPPDEBUG(LOG_DEBUG, ("mppe_rekey: cipher_encrypt failed\n"));
}
arc4_setup(&state->arc4, state->sha1_digest, state->keylen);
MEMCPY(state->session_key, state->sha1_digest, state->keylen);
arc4_crypt(&state->arc4, state->session_key, state->keylen);
} else {
memcpy(state->session_key, state->sha1_digest, state->keylen);
}
@ -151,7 +149,7 @@ static void mppe_rekey(struct ppp_mppe_state * state, int initial_key)
state->session_key[1] = 0x26;
state->session_key[2] = 0x9e;
}
crypto_blkcipher_setkey(state->arc4, state->session_key, state->keylen);
arc4_crypt(&state->arc4, state->session_key, state->keylen);
}
/*
@ -170,13 +168,6 @@ static void *mppe_alloc(unsigned char *options, int optlen)
if (state == NULL)
goto out;
state->arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(state->arc4)) {
state->arc4 = NULL;
goto out_free;
}
/* Save keys. */
memcpy(state->master_key, &options[CILEN_MPPE],
sizeof(state->master_key));
@ -191,8 +182,6 @@ static void *mppe_alloc(unsigned char *options, int optlen)
return (void *)state;
out_free:
if (state->arc4)
crypto_free_blkcipher(state->arc4);
kfree(state);
out:
return NULL;
@ -205,8 +194,6 @@ static void mppe_free(void *arg)
{
struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
if (state) {
if (state->arc4)
crypto_free_blkcipher(state->arc4);
kfree(state);
}
}
@ -313,9 +300,7 @@ mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf,
int isize, int osize)
{
struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
struct blkcipher_desc desc = { .tfm = state->arc4 };
int proto;
struct scatterlist sg_in[1], sg_out[1];
/*
* Check that the protocol is in the range we handle.
@ -367,14 +352,8 @@ mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf,
isize -= 2;
/* Encrypt packet */
sg_init_table(sg_in, 1);
sg_init_table(sg_out, 1);
setup_sg(sg_in, ibuf, isize);
setup_sg(sg_out, obuf, osize);
if (crypto_blkcipher_encrypt(&desc, sg_out, sg_in, isize) != 0) {
PPPDEBUG(LOG_DEBUG, ("crypto_cypher_encrypt failed\n"));
return -1;
}
MEMCPY(obuf, ibuf, isize);
arc4_crypt(&state->arc4, obuf, isize);
state->stats.unc_bytes += isize;
state->stats.unc_packets++;
@ -420,11 +399,9 @@ mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
int osize)
{
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)
@ -557,14 +534,8 @@ mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
* Decrypt the first byte in order to check if it is
* a compressed or uncompressed protocol field.
*/
sg_init_table(sg_in, 1);
sg_init_table(sg_out, 1);
setup_sg(sg_in, ibuf, 1);
setup_sg(sg_out, obuf, 1);
if (crypto_blkcipher_decrypt(&desc, sg_out, sg_in, 1) != 0) {
PPPDEBUG(LOG_DEBUG, ("crypto_cypher_decrypt failed\n"));
return ERR_BUF;
}
obuf[0] = ibuf[0];
arc4_crypt(&state->arc4, obuf, 1);
/*
* Do PFC decompression.
@ -579,12 +550,8 @@ mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
}
/* 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)) {
PPPDEBUG(LOG_DEBUG, ("crypto_cypher_decrypt failed\n"));
return ERR_BUF;
}
MEMCPY(obuf+1, ibuf+1, isize-1);
arc4_crypt(&state->arc4, obuf+1, isize-1);
state->stats.unc_bytes += osize;
state->stats.unc_packets++;
@ -656,8 +623,6 @@ static struct compressor ppp_mppe = {
static int ppp_mppe_init(void)
{
int answer;
if (!(crypto_has_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC)))
return -ENODEV;
sha_pad = kmalloc(sizeof(struct sha_pad), GFP_KERNEL);
if (!sha_pad)