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 | |
40 | uint32_t |
41 | xts_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 | |
70 | int 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 | |
86 | int 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 | |
102 | void xts_done(symmetric_xts *xts __unused) |
103 | { |
104 | cc_clear(sizeof(xts->enc), xts->enc); |
105 | cc_clear(sizeof(xts->dec), xts->dec); |
106 | } |
107 | |