usr/src/common/net/wanboot/crypt/cbc.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2002-2003 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <sys/sysmacros.h>
  30 #if defined(_KERNEL) && !defined(_BOOT)
  31 #include <sys/systm.h>
  32 #else
  33 #include <strings.h>
  34 #endif
  35 #include "cbc.h"
  36
  37 #define CBC_MAX_BLOCK_SIZE      64
  38
  39 static void
  40 cbc_xorblock(uint8_t *lastp, uint8_t *thisp, int blocksize)
  41 {
  42         uint32_t *this32p;
  43         uint32_t *last32p;
  44         int i;
  45
  46         if (IS_P2ALIGNED(thisp, sizeof (uint32_t)) &&
  47             IS_P2ALIGNED(lastp, sizeof (uint32_t)) &&
  48             IS_P2ALIGNED(blocksize, sizeof (uint32_t))) {
  49                 /* LINTED */
  50                 this32p = (uint32_t *)thisp;
  51                 /* LINTED */
  52                 last32p = (uint32_t *)lastp;
  53                 for (i = 0; i < blocksize; i += 4) {
  54                         *this32p ^= *last32p;
  55                         this32p++;
  56                         last32p++;
  57                 }
  58         } else {
  59                 for (i = 0; i < blocksize; i++) {
  60                         thisp[i] ^= lastp[i];
  61                 }
  62         }
  63 }
  64
  65 boolean_t
  66 cbc_encrypt(cbc_handle_t *ch, uint8_t *data, size_t datalen,
  67         uint8_t *IV)
  68 {
  69         uint8_t *lastp;
  70         uint8_t *thisp;
  71         size_t i;
  72
  73         if (!IS_P2ALIGNED(datalen, ch->blocklen)) {
  74                 return (B_FALSE);
  75         }
  76
  77         thisp = data;
  78         lastp = IV;
  79
  80         for (i = 0; i < datalen; i += ch->blocklen) {
  81                 cbc_xorblock(lastp, thisp, ch->blocklen);
  82                 /* Encrypt the current block. */
  83                 ch->encrypt(ch->ks, thisp);
  84                 lastp = thisp;
  85                 thisp += ch->blocklen;
  86         }
  87
  88         bcopy(lastp, IV, ch->blocklen);
  89         return (B_TRUE);
  90 }
  91
  92 boolean_t
  93 cbc_decrypt(cbc_handle_t *ch, uint8_t *data, size_t datalen,
  94         uint8_t *IV)
  95 {
  96         uint8_t cbcblock[CBC_MAX_BLOCK_SIZE];
  97         uint8_t *lastp;
  98         uint8_t *thisp;
  99         size_t i;
 100
 101         if (!IS_P2ALIGNED(datalen, ch->blocklen)) {
 102                 return (B_FALSE);
 103         }
 104
 105         thisp = data;
 106         lastp = IV;
 107
 108         for (i = 0; i < datalen; i += ch->blocklen) {
 109
 110                 /* Copy the current ciphertext block. */
 111                 bcopy(thisp, cbcblock, ch->blocklen);
 112
 113                 /* Decrypt the current block. */
 114                 ch->decrypt(ch->ks, thisp);
 115
 116                 cbc_xorblock(lastp, thisp, ch->blocklen);
 117
 118                 /* Save the last ciphertext block. */
 119                 bcopy(cbcblock, lastp, ch->blocklen);
 120                 thisp += ch->blocklen;
 121         }
 122
 123         return (B_TRUE);
 124 }
 125
 126 void
 127 cbc_makehandle(cbc_handle_t *ch, void *cookie, uint32_t keysize,
 128         uint32_t blocksize, uint32_t ivsize,
 129         void (*encrypt)(void *, uint8_t *),
 130         void (*decrypt)(void *, uint8_t *))
 131 {
 132         ch->ks = cookie;
 133         ch->keylen = keysize;
 134         ch->blocklen = blocksize;
 135         ch->ivlen = ivsize;
 136         ch->encrypt = encrypt;
 137         ch->decrypt = decrypt;
 138 }