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(Using sed : sed -i '/^ \* \$Id\$/,+1 d') Fix manually some typo (in export_object_dicom.c and crc16-plain.c) Change-Id: I4c1ae68d1c4afeace8cb195b53c715cf9e1227a8 Reviewed-on: https://code.wireshark.org/review/497 Reviewed-by: Anders Broman <a.broman58@gmail.com>
251 lines
7.3 KiB
C
251 lines
7.3 KiB
C
/* eax.c
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* Encryption and decryption routines implementing the EAX' encryption mode
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* Copyright 2010, Edward J. Beroset, edward.j.beroset@us.elster.com
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <stdlib.h>
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#ifdef HAVE_LIBGCRYPT
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#include <string.h>
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/* Use libgcrypt for cipher libraries. */
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#include <wsutil/wsgcrypt.h>
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#include "eax.h"
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typedef struct {
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guint8 L[EAX_SIZEOF_KEY];
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guint8 D[EAX_SIZEOF_KEY];
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guint8 Q[EAX_SIZEOF_KEY];
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} eax_s;
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static eax_s instance;
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/* these are defined as macros so they'll be easy to redo in assembly if desired */
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#define BLK_CPY(dst, src) { memcpy(dst, src, EAX_SIZEOF_KEY); }
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#define BLK_XOR(dst, src) { int z; for (z=0; z < EAX_SIZEOF_KEY; z++) dst[z] ^= src[z]; }
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static void Dbl(guint8 *out, const guint8 *in);
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static void CTR(const guint8 *ws, guint8 *pK, guint8 *pN, guint16 SizeN);
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static void CMAC(guint8 *pK, guint8 *ws, const guint8 *pN, guint16 SizeN);
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static void dCMAC(guint8 *pK, guint8 *ws, const guint8 *pN, guint16 SizeN, const guint8 *pC, guint16 SizeC);
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void AesEncrypt(unsigned char msg[EAX_SIZEOF_KEY], unsigned char key[EAX_SIZEOF_KEY]);
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/*!
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Decrypts cleartext data using EAX' mode (see ANSI Standard C12.22-2008).
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@param[in] pN pointer to cleartext (canonified form)
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@param[in] pK pointer to secret key
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@param[in,out] pC pointer to ciphertext
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@param[in] SizeN byte length of cleartext (pN) buffer
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@param[in] SizeK byte length of secret key (pK)
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@param[in] SizeC byte length of ciphertext (pC) buffer
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@param[in] pMac four-byte Message Authentication Code
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@param[in] Mode EAX_MODE_CLEARTEXT_AUTH or EAX_MODE_CIPHERTEXT_AUTH
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@return TRUE if message has been authenticated; FALSE if not
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authenticated, invalid Mode or error
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*/
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gboolean Eax_Decrypt(guint8 *pN, guint8 *pK, guint8 *pC,
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guint32 SizeN, guint32 SizeK, guint32 SizeC, MAC_T *pMac,
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guint8 Mode)
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{
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guint8 wsn[EAX_SIZEOF_KEY];
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guint8 wsc[EAX_SIZEOF_KEY];
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int i;
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/* key size must match this implementation */
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if (SizeK != EAX_SIZEOF_KEY)
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return FALSE;
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/* the key is new */
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for (i = 0; i < EAX_SIZEOF_KEY; i++)
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instance.L[i] = 0;
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AesEncrypt(instance.L, pK);
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Dbl(instance.D, instance.L);
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Dbl(instance.Q, instance.D);
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/* the key is set up */
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/* first copy the nonce into our working space */
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BLK_CPY(wsn, instance.D);
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if (Mode == EAX_MODE_CLEARTEXT_AUTH) {
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dCMAC(pK, wsn, pN, SizeN, pC, SizeC);
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} else {
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CMAC(pK, wsn, pN, SizeN);
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}
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/*
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* In authentication mode the inputs are: pN, pK (and associated sizes),
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* the result is the 4 byte MAC.
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*/
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if (Mode == EAX_MODE_CLEARTEXT_AUTH)
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{
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return (memcmp(pMac, &wsn[EAX_SIZEOF_KEY-sizeof(*pMac)], sizeof(*pMac)) ? FALSE : TRUE);
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}
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/*
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* In cipher mode the inputs are: pN, pK, pP (and associated sizes),
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* the results are pC (and its size) along with the 4 byte MAC.
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*/
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else if (Mode == EAX_MODE_CIPHERTEXT_AUTH)
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{
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if (SizeC == 0)
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return (memcmp(pMac, &wsn[EAX_SIZEOF_KEY-sizeof(*pMac)], sizeof(*pMac)) ? FALSE : TRUE);
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{
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/* first copy the nonce into our working space */
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BLK_CPY(wsc, instance.Q);
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CMAC(pK, wsc, pC, SizeC);
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BLK_XOR(wsc, wsn);
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}
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if (memcmp(pMac, &wsc[EAX_SIZEOF_KEY-sizeof(*pMac)], sizeof(*pMac)) == 0)
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{
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CTR(wsn, pK, pC, SizeC);
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return TRUE;
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}
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}
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return FALSE;
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}
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/* set up D or Q from L */
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static void Dbl(guint8 *out, const guint8 *in)
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{
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int i;
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guint8 carry = 0;
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/* this might be a lot more efficient in assembly language */
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for (i=0; i < EAX_SIZEOF_KEY; i++)
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{
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out[i] = ( in[i] << 1 ) | carry;
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carry = (in[i] & 0x80) ? 1 : 0;
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}
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if (carry)
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out[0] ^= 0x87;
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}
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static void CMAC(guint8 *pK, guint8 *ws, const guint8 *pN, guint16 SizeN)
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{
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dCMAC(pK, ws, pN, SizeN, NULL, 0);
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}
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static void dCMAC(guint8 *pK, guint8 *ws, const guint8 *pN, guint16 SizeN, const guint8 *pC, guint16 SizeC)
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{
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gcry_cipher_hd_t cipher_hd;
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guint8 *work;
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guint8 *ptr;
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guint16 SizeT = SizeN + SizeC;
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guint16 worksize = SizeT;
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/* worksize must be an integral multiple of 16 */
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if (SizeT & 0xf) {
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worksize += 0x10 - (worksize & 0xf);
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}
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work = (guint8 *)g_malloc(worksize);
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if (work == NULL) {
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return;
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}
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memcpy(work, pN, SizeN);
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if (pC != NULL) {
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memcpy(&work[SizeN], pC, SizeC);
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}
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/*
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* pad the data if necessary, and XOR Q or D, depending on
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* whether data was padded or not
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*/
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if (worksize != SizeT) {
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work[SizeT] = 0x80;
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for (ptr = &work[SizeT+1]; ptr < &work[worksize]; ptr++)
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*ptr = 0;
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ptr= &work[worksize-0x10];
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BLK_XOR(ptr, instance.Q);
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} else {
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ptr = &work[worksize-0x10];
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BLK_XOR(ptr, instance.D);
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}
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/* open the cipher */
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if (gcry_cipher_open(&cipher_hd, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_CBC,0)){/* GCRY_CIPHER_CBC_MAC)) { */
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g_free(work);
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return;
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}
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if (gcry_cipher_setkey(cipher_hd, pK, EAX_SIZEOF_KEY)) {
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g_free(work);
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gcry_cipher_close(cipher_hd);
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return;
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}
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if (gcry_cipher_setiv(cipher_hd, ws, EAX_SIZEOF_KEY)) {
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g_free(work);
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gcry_cipher_close(cipher_hd);
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return;
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}
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if (gcry_cipher_encrypt(cipher_hd, work, worksize, work, worksize)) {
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g_free(work);
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gcry_cipher_close(cipher_hd);
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return;
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}
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memcpy(ws, ptr, EAX_SIZEOF_KEY);
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g_free(work);
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gcry_cipher_close(cipher_hd);
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return;
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}
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static void CTR(const guint8 *ws, guint8 *pK, guint8 *pN, guint16 SizeN)
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{
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gcry_cipher_hd_t cipher_hd;
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guint8 ctr[EAX_SIZEOF_KEY];
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BLK_CPY(ctr, ws);
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ctr[12] &= 0x7f;
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ctr[14] &= 0x7f;
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/* open the cipher */
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if (gcry_cipher_open(&cipher_hd, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_CTR, 0)) {
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return;
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}
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if (gcry_cipher_setkey(cipher_hd, pK, EAX_SIZEOF_KEY)) {
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gcry_cipher_close(cipher_hd);
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return;
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}
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if (gcry_cipher_setctr(cipher_hd, ctr, EAX_SIZEOF_KEY)) {
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gcry_cipher_close(cipher_hd);
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return;
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}
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if (gcry_cipher_encrypt(cipher_hd, pN, SizeN, pN, SizeN)) {
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gcry_cipher_close(cipher_hd);
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return;
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}
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gcry_cipher_close(cipher_hd);
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return;
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}
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void AesEncrypt(unsigned char msg[EAX_SIZEOF_KEY], unsigned char key[EAX_SIZEOF_KEY])
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{
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gcry_cipher_hd_t cipher_hd;
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/* open the cipher */
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if (gcry_cipher_open(&cipher_hd, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_ECB, 0)) {
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return;
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}
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if (gcry_cipher_setkey(cipher_hd, key, EAX_SIZEOF_KEY)) {
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gcry_cipher_close(cipher_hd);
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return;
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}
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if (gcry_cipher_encrypt(cipher_hd, msg, EAX_SIZEOF_KEY, msg, EAX_SIZEOF_KEY)) {
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gcry_cipher_close(cipher_hd);
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return;
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}
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gcry_cipher_close(cipher_hd);
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return;
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}
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#endif /* HAVE_LIBGCRYPT */
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