1/* 2 * Copyright (c) 2012 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29#include <libkern/crypto/crypto_internal.h> 30#include <libkern/libkern.h> 31#include <libkern/crypto/aesxts.h> 32#include <corecrypto/ccmode.h> 33#include <corecrypto/ccpad.h> 34#include <kern/debug.h> 35 36/* 37 * These are the interfaces required for XTS-AES support 38 */ 39 40uint32_t 41xts_start(uint32_t cipher __unused, // ignored - we're doing this for xts-aes only 42 const uint8_t *IV __unused, // ignored 43 const uint8_t *key1, int keylen, 44 const uint8_t *key2, int tweaklen __unused, // both keys are the same size for xts 45 uint32_t num_rounds __unused, // ignored 46 uint32_t options __unused, // ignored 47 symmetric_xts *xts) 48{ 49 const struct ccmode_xts *enc, *dec; 50 51 if(!g_crypto_funcs) 52 panic("%s: corecrypto not registered!\n", __FUNCTION__); 53 54 enc = g_crypto_funcs->ccaes_xts_encrypt; 55 dec = g_crypto_funcs->ccaes_xts_decrypt; 56 57 if(!enc && !dec) 58 panic("%s: xts mode not registered? enc=%p, dec=%p\n", __FUNCTION__, enc, dec); 59 60 /* Make sure the context size for the mode fits in the one we have */ 61 if((enc->size>sizeof(xts->enc)) || (dec->size>sizeof(xts->dec))) 62 panic("%s: inconsistent size for AES-XTS context", __FUNCTION__); 63 64 enc->init(enc, xts->enc, keylen, key1, key2); 65 dec->init(dec, xts->dec, keylen, key1, key2); 66 67 return 0; //never fails 68} 69 70int xts_encrypt(const uint8_t *pt, unsigned long ptlen, 71 uint8_t *ct, 72 const uint8_t *iv, // this can be considered the sector IV for this use 73 symmetric_xts *xts) 74{ 75 const struct ccmode_xts *xtsenc = g_crypto_funcs->ccaes_xts_encrypt; 76 ccxts_tweak_decl(xtsenc->tweak_size, tweak); 77 78 if(ptlen%16) panic("xts encrypt not a multiple of block size\n"); 79 80 xtsenc->set_tweak(xts->enc, tweak, iv); 81 xtsenc->xts(xts->enc, tweak, ptlen/16, pt, ct); 82 83 return 0; //never fails 84} 85 86int xts_decrypt(const uint8_t *ct, unsigned long ptlen, 87 uint8_t *pt, 88 const uint8_t *iv, // this can be considered the sector IV for this use 89 symmetric_xts *xts) 90{ 91 const struct ccmode_xts *xtsdec = g_crypto_funcs->ccaes_xts_decrypt; 92 ccxts_tweak_decl(xtsdec->tweak_size, tweak); 93 94 if(ptlen%16) panic("xts decrypt not a multiple of block size\n"); 95 96 xtsdec->set_tweak(xts->dec, tweak, iv); 97 xtsdec->xts(xts->dec, tweak, ptlen/16, ct, pt); 98 99 return 0; //never fails 100} 101 102void xts_done(symmetric_xts *xts __unused) 103{ 104 105} 106