mirror of
https://github.com/xcat2/xNBA.git
synced 2024-11-26 03:09:12 +00:00
[wpa] Add CCMP backend (new AES-based cryptosystem)
Signed-off-by: Marty Connor <mdc@etherboot.org>
This commit is contained in:
Joshua Oreman
Marty Connor
parent
8106cb130b
commit
5240fee38f
@ -39,6 +39,11 @@ REQUIRE_OBJECT ( wireless_errors );
|
||||
REQUIRE_OBJECT ( wep );
|
||||
#endif
|
||||
|
||||
#ifdef CRYPTO_80211_WPA2
|
||||
#define CRYPTO_80211_WPA
|
||||
REQUIRE_OBJECT ( wpa_ccmp );
|
||||
#endif
|
||||
|
||||
#ifdef CRYPTO_80211_WPA
|
||||
REQUIRE_OBJECT ( wpa_psk );
|
||||
REQUIRE_OBJECT ( wpa_tkip );
|
||||
|
||||
@ -70,6 +70,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
|
||||
*/
|
||||
#define CRYPTO_80211_WEP /* WEP encryption (deprecated and insecure!) */
|
||||
#define CRYPTO_80211_WPA /* WPA Personal, authenticating with passphrase */
|
||||
#undef CRYPTO_80211_WPA2 /* Add support for stronger WPA cryptography */
|
||||
|
||||
/*
|
||||
* Name resolution modules
|
||||
|
||||
@ -164,6 +164,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
|
||||
#define ERRFILE_wpa ( ERRFILE_NET | 0x00260000 )
|
||||
#define ERRFILE_wpa_psk ( ERRFILE_NET | 0x00270000 )
|
||||
#define ERRFILE_wpa_tkip ( ERRFILE_NET | 0x00280000 )
|
||||
#define ERRFILE_wpa_ccmp ( ERRFILE_NET | 0x00290000 )
|
||||
|
||||
#define ERRFILE_image ( ERRFILE_IMAGE | 0x00000000 )
|
||||
#define ERRFILE_elf ( ERRFILE_IMAGE | 0x00010000 )
|
||||
|
||||
528
src/net/80211/wpa_ccmp.c
Normal file
528
src/net/80211/wpa_ccmp.c
Normal file
@ -0,0 +1,528 @@
|
||||
/*
|
||||
* Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License as
|
||||
* published by the Free Software Foundation; either version 2 of the
|
||||
* License, or any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful, but
|
||||
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
FILE_LICENCE ( GPL2_OR_LATER );
|
||||
|
||||
#include <gpxe/net80211.h>
|
||||
#include <gpxe/crypto.h>
|
||||
#include <gpxe/hmac.h>
|
||||
#include <gpxe/sha1.h>
|
||||
#include <gpxe/aes.h>
|
||||
#include <gpxe/wpa.h>
|
||||
#include <byteswap.h>
|
||||
#include <errno.h>
|
||||
|
||||
/** @file
|
||||
*
|
||||
* Backend for WPA using the CCMP encryption method
|
||||
*/
|
||||
|
||||
/** Context for CCMP encryption and decryption */
|
||||
struct ccmp_ctx
|
||||
{
|
||||
/** AES context - only ever used for encryption */
|
||||
u8 aes_ctx[AES_CTX_SIZE];
|
||||
|
||||
/** Most recently sent packet number */
|
||||
u64 tx_seq;
|
||||
|
||||
/** Most recently received packet number */
|
||||
u64 rx_seq;
|
||||
};
|
||||
|
||||
/** Header structure at the beginning of CCMP frame data */
|
||||
struct ccmp_head
|
||||
{
|
||||
u8 pn_lo[2]; /**< Bytes 0 and 1 of packet number */
|
||||
u8 _rsvd; /**< Reserved byte */
|
||||
u8 kid; /**< Key ID and ExtIV byte */
|
||||
u8 pn_hi[4]; /**< Bytes 2-5 (2 first) of packet number */
|
||||
} __attribute__ (( packed ));
|
||||
|
||||
|
||||
/** CCMP header overhead */
|
||||
#define CCMP_HEAD_LEN 8
|
||||
|
||||
/** CCMP MIC trailer overhead */
|
||||
#define CCMP_MIC_LEN 8
|
||||
|
||||
/** CCMP nonce length */
|
||||
#define CCMP_NONCE_LEN 13
|
||||
|
||||
/** CCMP nonce structure */
|
||||
struct ccmp_nonce
|
||||
{
|
||||
u8 prio; /**< Packet priority, 0 for non-QoS */
|
||||
u8 a2[ETH_ALEN]; /**< Address 2 from packet header (sender) */
|
||||
u8 pn[6]; /**< Packet number */
|
||||
} __attribute__ (( packed ));
|
||||
|
||||
/** CCMP additional authentication data length (for non-QoS, non-WDS frames) */
|
||||
#define CCMP_AAD_LEN 22
|
||||
|
||||
/** CCMP additional authentication data structure */
|
||||
struct ccmp_aad
|
||||
{
|
||||
u16 fc; /**< Frame Control field */
|
||||
u8 a1[6]; /**< Address 1 */
|
||||
u8 a2[6]; /**< Address 2 */
|
||||
u8 a3[6]; /**< Address 3 */
|
||||
u16 seq; /**< Sequence Control field */
|
||||
/* Address 4 and QoS Control are included if present */
|
||||
} __attribute__ (( packed ));
|
||||
|
||||
/** Mask for Frame Control field in AAD */
|
||||
#define CCMP_AAD_FC_MASK 0xC38F
|
||||
|
||||
/** Mask for Sequence Control field in AAD */
|
||||
#define CCMP_AAD_SEQ_MASK 0x000F
|
||||
|
||||
|
||||
/**
|
||||
* Convert 6-byte LSB packet number to 64-bit integer
|
||||
*
|
||||
* @v pn Pointer to 6-byte packet number
|
||||
* @ret v 64-bit integer value of @a pn
|
||||
*/
|
||||
static u64 pn_to_u64 ( const u8 *pn )
|
||||
{
|
||||
int i;
|
||||
u64 ret = 0;
|
||||
|
||||
for ( i = 5; i >= 0; i-- ) {
|
||||
ret <<= 8;
|
||||
ret |= pn[i];
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* Convert 64-bit integer to 6-byte packet number
|
||||
*
|
||||
* @v v 64-bit integer
|
||||
* @v msb If TRUE, reverse the output PN to be in MSB order
|
||||
* @ret pn 6-byte packet number
|
||||
*
|
||||
* The PN is stored in LSB order in the packet header and in MSB order
|
||||
* in the nonce. WHYYYYY?
|
||||
*/
|
||||
static void u64_to_pn ( u64 v, u8 *pn, int msb )
|
||||
{
|
||||
int i;
|
||||
u8 *pnp = pn + ( msb ? 5 : 0 );
|
||||
int delta = ( msb ? -1 : +1 );
|
||||
|
||||
for ( i = 0; i < 6; i++ ) {
|
||||
*pnp = v & 0xFF;
|
||||
pnp += delta;
|
||||
v >>= 8;
|
||||
}
|
||||
}
|
||||
|
||||
/** Value for @a msb argument of u64_to_pn() for MSB output */
|
||||
#define PN_MSB 1
|
||||
|
||||
/** Value for @a msb argument of u64_to_pn() for LSB output */
|
||||
#define PN_LSB 0
|
||||
|
||||
|
||||
|
||||
/**
|
||||
* Initialise CCMP state and install key
|
||||
*
|
||||
* @v crypto CCMP cryptosystem structure
|
||||
* @v key Pointer to 16-byte temporal key to install
|
||||
* @v keylen Length of key (16 bytes)
|
||||
* @v rsc Initial receive sequence counter
|
||||
*/
|
||||
static int ccmp_init ( struct net80211_crypto *crypto, const void *key,
|
||||
int keylen, const void *rsc )
|
||||
{
|
||||
struct ccmp_ctx *ctx = crypto->priv;
|
||||
|
||||
if ( keylen != 16 )
|
||||
return -EINVAL;
|
||||
|
||||
if ( rsc )
|
||||
ctx->rx_seq = pn_to_u64 ( rsc );
|
||||
|
||||
cipher_setkey ( &aes_algorithm, ctx->aes_ctx, key, keylen );
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Encrypt or decrypt data stream using AES in Counter mode
|
||||
*
|
||||
* @v ctx CCMP cryptosystem context
|
||||
* @v nonce Nonce value, 13 bytes
|
||||
* @v srcv Data to encrypt or decrypt
|
||||
* @v len Number of bytes pointed to by @a src
|
||||
* @v msrcv MIC value to encrypt or decrypt (may be NULL)
|
||||
* @ret destv Encrypted or decrypted data
|
||||
* @ret mdestv Encrypted or decrypted MIC value
|
||||
*
|
||||
* This assumes CCMP parameters of L=2 and M=8. The algorithm is
|
||||
* defined in RFC 3610.
|
||||
*/
|
||||
static void ccmp_ctr_xor ( struct ccmp_ctx *ctx, const void *nonce,
|
||||
const void *srcv, void *destv, int len,
|
||||
const void *msrcv, void *mdestv )
|
||||
{
|
||||
u8 A[16], S[16];
|
||||
u16 ctr;
|
||||
int i;
|
||||
const u8 *src = srcv, *msrc = msrcv;
|
||||
u8 *dest = destv, *mdest = mdestv;
|
||||
|
||||
A[0] = 0x01; /* flags, L' = L - 1 = 1, other bits rsvd */
|
||||
memcpy ( A + 1, nonce, CCMP_NONCE_LEN );
|
||||
|
||||
if ( msrcv ) {
|
||||
A[14] = A[15] = 0;
|
||||
|
||||
cipher_encrypt ( &aes_algorithm, ctx->aes_ctx, A, S, 16 );
|
||||
|
||||
for ( i = 0; i < 8; i++ ) {
|
||||
*mdest++ = *msrc++ ^ S[i];
|
||||
}
|
||||
}
|
||||
|
||||
for ( ctr = 1 ;; ctr++ ) {
|
||||
A[14] = ctr >> 8;
|
||||
A[15] = ctr & 0xFF;
|
||||
|
||||
cipher_encrypt ( &aes_algorithm, ctx->aes_ctx, A, S, 16 );
|
||||
|
||||
for ( i = 0; i < len && i < 16; i++ )
|
||||
*dest++ = *src++ ^ S[i];
|
||||
|
||||
if ( len <= 16 )
|
||||
break; /* we're done */
|
||||
|
||||
len -= 16;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Advance one block in CBC-MAC calculation
|
||||
*
|
||||
* @v aes_ctx AES encryption context with key set
|
||||
* @v B Cleartext block to incorporate (16 bytes)
|
||||
* @v X Previous ciphertext block (16 bytes)
|
||||
* @ret B Clobbered
|
||||
* @ret X New ciphertext block (16 bytes)
|
||||
*
|
||||
* This function does X := E[key] ( X ^ B ).
|
||||
*/
|
||||
static void ccmp_feed_cbc_mac ( void *aes_ctx, u8 *B, u8 *X )
|
||||
{
|
||||
int i;
|
||||
for ( i = 0; i < 16; i++ )
|
||||
B[i] ^= X[i];
|
||||
cipher_encrypt ( &aes_algorithm, aes_ctx, B, X, 16 );
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Calculate MIC on plaintext data using CBC-MAC
|
||||
*
|
||||
* @v ctx CCMP cryptosystem context
|
||||
* @v nonce Nonce value, 13 bytes
|
||||
* @v data Data to calculate MIC over
|
||||
* @v datalen Length of @a data
|
||||
* @v aad Additional authentication data, for MIC but not encryption
|
||||
* @ret mic MIC value (unencrypted), 8 bytes
|
||||
*
|
||||
* @a aadlen is assumed to be 22 bytes long, as it always is for
|
||||
* 802.11 use when transmitting non-QoS, not-between-APs frames (the
|
||||
* only type we deal with).
|
||||
*/
|
||||
static void ccmp_cbc_mac ( struct ccmp_ctx *ctx, const void *nonce,
|
||||
const void *data, u16 datalen,
|
||||
const void *aad, void *mic )
|
||||
{
|
||||
u8 X[16], B[16];
|
||||
|
||||
/* Zeroth block: flags, nonce, length */
|
||||
|
||||
/* Rsv AAD - M'- - L'-
|
||||
* 0 1 0 1 1 0 0 1 for an 8-byte MAC and 2-byte message length
|
||||
*/
|
||||
B[0] = 0x59;
|
||||
memcpy ( B + 1, nonce, CCMP_NONCE_LEN );
|
||||
B[14] = datalen >> 8;
|
||||
B[15] = datalen & 0xFF;
|
||||
|
||||
cipher_encrypt ( &aes_algorithm, ctx->aes_ctx, B, X, 16 );
|
||||
|
||||
/* First block: AAD length field and 14 bytes of AAD */
|
||||
B[0] = 0;
|
||||
B[1] = CCMP_AAD_LEN;
|
||||
memcpy ( B + 2, aad, 14 );
|
||||
|
||||
ccmp_feed_cbc_mac ( ctx->aes_ctx, B, X );
|
||||
|
||||
/* Second block: Remaining 8 bytes of AAD, 8 bytes zero pad */
|
||||
memcpy ( B, aad + 14, 8 );
|
||||
memset ( B + 8, 0, 8 );
|
||||
|
||||
ccmp_feed_cbc_mac ( ctx->aes_ctx, B, X );
|
||||
|
||||
/* Message blocks */
|
||||
while ( datalen ) {
|
||||
if ( datalen >= 16 ) {
|
||||
memcpy ( B, data, 16 );
|
||||
datalen -= 16;
|
||||
} else {
|
||||
memcpy ( B, data, datalen );
|
||||
memset ( B + datalen, 0, 16 - datalen );
|
||||
datalen = 0;
|
||||
}
|
||||
|
||||
ccmp_feed_cbc_mac ( ctx->aes_ctx, B, X );
|
||||
|
||||
data += 16;
|
||||
}
|
||||
|
||||
/* Get MIC from final value of X */
|
||||
memcpy ( mic, X, 8 );
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Encapsulate and encrypt a packet using CCMP
|
||||
*
|
||||
* @v crypto CCMP cryptosystem
|
||||
* @v iob I/O buffer containing cleartext packet
|
||||
* @ret eiob I/O buffer containing encrypted packet
|
||||
*/
|
||||
struct io_buffer * ccmp_encrypt ( struct net80211_crypto *crypto,
|
||||
struct io_buffer *iob )
|
||||
{
|
||||
struct ccmp_ctx *ctx = crypto->priv;
|
||||
struct ieee80211_frame *hdr = iob->data;
|
||||
struct io_buffer *eiob;
|
||||
const int hdrlen = IEEE80211_TYP_FRAME_HEADER_LEN;
|
||||
int datalen = iob_len ( iob ) - hdrlen;
|
||||
struct ccmp_head head;
|
||||
struct ccmp_nonce nonce;
|
||||
struct ccmp_aad aad;
|
||||
u8 mic[8], tx_pn[6];
|
||||
void *edata, *emic;
|
||||
|
||||
ctx->tx_seq++;
|
||||
u64_to_pn ( ctx->tx_seq, tx_pn, PN_LSB );
|
||||
|
||||
/* Allocate memory */
|
||||
eiob = alloc_iob ( iob_len ( iob ) + CCMP_HEAD_LEN + CCMP_MIC_LEN );
|
||||
if ( ! eiob )
|
||||
return NULL;
|
||||
|
||||
/* Copy frame header */
|
||||
memcpy ( iob_put ( eiob, hdrlen ), iob->data, hdrlen );
|
||||
hdr = eiob->data;
|
||||
hdr->fc |= IEEE80211_FC_PROTECTED;
|
||||
|
||||
/* Fill in packet number and extended IV */
|
||||
memcpy ( head.pn_lo, tx_pn, 2 );
|
||||
memcpy ( head.pn_hi, tx_pn + 2, 4 );
|
||||
head.kid = 0x20; /* have Extended IV, key ID 0 */
|
||||
head._rsvd = 0;
|
||||
memcpy ( iob_put ( eiob, sizeof ( head ) ), &head, sizeof ( head ) );
|
||||
|
||||
/* Form nonce */
|
||||
nonce.prio = 0;
|
||||
memcpy ( nonce.a2, hdr->addr2, ETH_ALEN );
|
||||
u64_to_pn ( ctx->tx_seq, nonce.pn, PN_MSB );
|
||||
|
||||
/* Form additional authentication data */
|
||||
aad.fc = hdr->fc & CCMP_AAD_FC_MASK;
|
||||
memcpy ( aad.a1, hdr->addr1, 3 * ETH_ALEN ); /* all 3 at once */
|
||||
aad.seq = hdr->seq & CCMP_AAD_SEQ_MASK;
|
||||
|
||||
/* Calculate MIC over the data */
|
||||
ccmp_cbc_mac ( ctx, &nonce, iob->data + hdrlen, datalen, &aad, mic );
|
||||
|
||||
/* Copy and encrypt data and MIC */
|
||||
edata = iob_put ( eiob, datalen );
|
||||
emic = iob_put ( eiob, CCMP_MIC_LEN );
|
||||
ccmp_ctr_xor ( ctx, &nonce,
|
||||
iob->data + hdrlen, edata, datalen,
|
||||
mic, emic );
|
||||
|
||||
/* Done! */
|
||||
DBGC2 ( ctx, "WPA-CCMP %p: encrypted packet %p -> %p\n", ctx,
|
||||
iob, eiob );
|
||||
|
||||
return eiob;
|
||||
}
|
||||
|
||||
/**
|
||||
* Decrypt a packet using CCMP
|
||||
*
|
||||
* @v crypto CCMP cryptosystem
|
||||
* @v eiob I/O buffer containing encrypted packet
|
||||
* @ret iob I/O buffer containing cleartext packet
|
||||
*/
|
||||
static struct io_buffer * ccmp_decrypt ( struct net80211_crypto *crypto,
|
||||
struct io_buffer *eiob )
|
||||
{
|
||||
struct ccmp_ctx *ctx = crypto->priv;
|
||||
struct ieee80211_frame *hdr;
|
||||
struct io_buffer *iob;
|
||||
const int hdrlen = IEEE80211_TYP_FRAME_HEADER_LEN;
|
||||
int datalen = iob_len ( eiob ) - hdrlen - CCMP_HEAD_LEN - CCMP_MIC_LEN;
|
||||
struct ccmp_head *head;
|
||||
struct ccmp_nonce nonce;
|
||||
struct ccmp_aad aad;
|
||||
u8 rx_pn[6], their_mic[8], our_mic[8];
|
||||
|
||||
iob = alloc_iob ( hdrlen + datalen );
|
||||
if ( ! iob )
|
||||
return NULL;
|
||||
|
||||
/* Copy frame header */
|
||||
memcpy ( iob_put ( iob, hdrlen ), eiob->data, hdrlen );
|
||||
hdr = iob->data;
|
||||
hdr->fc &= ~IEEE80211_FC_PROTECTED;
|
||||
|
||||
/* Check and update RX packet number */
|
||||
head = eiob->data + hdrlen;
|
||||
memcpy ( rx_pn, head->pn_lo, 2 );
|
||||
memcpy ( rx_pn + 2, head->pn_hi, 4 );
|
||||
|
||||
if ( pn_to_u64 ( rx_pn ) <= ctx->rx_seq ) {
|
||||
DBGC ( ctx, "WPA-CCMP %p: packet received out of order "
|
||||
"(%012llx <= %012llx)\n", ctx, pn_to_u64 ( rx_pn ),
|
||||
ctx->rx_seq );
|
||||
free_iob ( iob );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
ctx->rx_seq = pn_to_u64 ( rx_pn );
|
||||
DBGC2 ( ctx, "WPA-CCMP %p: RX packet number %012llx\n", ctx, ctx->rx_seq );
|
||||
|
||||
/* Form nonce */
|
||||
nonce.prio = 0;
|
||||
memcpy ( nonce.a2, hdr->addr2, ETH_ALEN );
|
||||
u64_to_pn ( ctx->rx_seq, nonce.pn, PN_MSB );
|
||||
|
||||
/* Form additional authentication data */
|
||||
aad.fc = ( hdr->fc & CCMP_AAD_FC_MASK ) | IEEE80211_FC_PROTECTED;
|
||||
memcpy ( aad.a1, hdr->addr1, 3 * ETH_ALEN ); /* all 3 at once */
|
||||
aad.seq = hdr->seq & CCMP_AAD_SEQ_MASK;
|
||||
|
||||
/* Copy-decrypt data and MIC */
|
||||
ccmp_ctr_xor ( ctx, &nonce, eiob->data + hdrlen + sizeof ( *head ),
|
||||
iob_put ( iob, datalen ), datalen,
|
||||
eiob->tail - CCMP_MIC_LEN, their_mic );
|
||||
|
||||
/* Check MIC */
|
||||
ccmp_cbc_mac ( ctx, &nonce, iob->data + hdrlen, datalen, &aad,
|
||||
our_mic );
|
||||
|
||||
if ( memcmp ( their_mic, our_mic, CCMP_MIC_LEN ) != 0 ) {
|
||||
DBGC2 ( ctx, "WPA-CCMP %p: MIC failure\n", ctx );
|
||||
free_iob ( iob );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
DBGC2 ( ctx, "WPA-CCMP %p: decrypted packet %p -> %p\n", ctx,
|
||||
eiob, iob );
|
||||
|
||||
return iob;
|
||||
}
|
||||
|
||||
|
||||
/** CCMP cryptosystem */
|
||||
struct net80211_crypto ccmp_crypto __net80211_crypto = {
|
||||
.algorithm = NET80211_CRYPT_CCMP,
|
||||
.init = ccmp_init,
|
||||
.encrypt = ccmp_encrypt,
|
||||
.decrypt = ccmp_decrypt,
|
||||
.priv_len = sizeof ( struct ccmp_ctx ),
|
||||
};
|
||||
|
||||
|
||||
|
||||
|
||||
/**
|
||||
* Calculate HMAC-SHA1 MIC for EAPOL-Key frame
|
||||
*
|
||||
* @v kck Key Confirmation Key, 16 bytes
|
||||
* @v msg Message to calculate MIC over
|
||||
* @v len Number of bytes to calculate MIC over
|
||||
* @ret mic Calculated MIC, 16 bytes long
|
||||
*/
|
||||
static void ccmp_kie_mic ( const void *kck, const void *msg, size_t len,
|
||||
void *mic )
|
||||
{
|
||||
u8 sha1_ctx[SHA1_CTX_SIZE];
|
||||
u8 kckb[16];
|
||||
u8 hash[SHA1_SIZE];
|
||||
size_t kck_len = 16;
|
||||
|
||||
memcpy ( kckb, kck, kck_len );
|
||||
|
||||
hmac_init ( &sha1_algorithm, sha1_ctx, kckb, &kck_len );
|
||||
hmac_update ( &sha1_algorithm, sha1_ctx, msg, len );
|
||||
hmac_final ( &sha1_algorithm, sha1_ctx, kckb, &kck_len, hash );
|
||||
|
||||
memcpy ( mic, hash, 16 );
|
||||
}
|
||||
|
||||
/**
|
||||
* Decrypt key data in EAPOL-Key frame
|
||||
*
|
||||
* @v kek Key Encryption Key, 16 bytes
|
||||
* @v iv Initialisation vector, 16 bytes (unused)
|
||||
* @v msg Message to decrypt
|
||||
* @v len Length of message
|
||||
* @ret msg Decrypted message in place of original
|
||||
* @ret len Adjusted downward for 8 bytes of overhead
|
||||
* @ret rc Return status code
|
||||
*
|
||||
* The returned message may still contain padding of 0xDD followed by
|
||||
* zero or more 0x00 octets. It is impossible to remove the padding
|
||||
* without parsing the IEs in the packet (another design decision that
|
||||
* tends to make one question the 802.11i committee's intelligence...)
|
||||
*/
|
||||
static int ccmp_kie_decrypt ( const void *kek, const void *iv __unused,
|
||||
void *msg, u16 *len )
|
||||
{
|
||||
if ( *len % 8 != 0 )
|
||||
return -EINVAL;
|
||||
|
||||
if ( aes_unwrap ( kek, msg, msg, *len / 8 - 1 ) != 0 )
|
||||
return -EINVAL;
|
||||
|
||||
*len -= 8;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/** CCMP-style key integrity and encryption handler */
|
||||
struct wpa_kie ccmp_kie __wpa_kie = {
|
||||
.version = EAPOL_KEY_VERSION_WPA2,
|
||||
.mic = ccmp_kie_mic,
|
||||
.decrypt = ccmp_kie_decrypt,
|
||||
};
|
||||
Loading…
Reference in New Issue
Block a user