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!" , __FUNCTION__); |
53 | } |
54 | |
55 | enc = g_crypto_funcs->ccaes_xts_encrypt; |
56 | dec = g_crypto_funcs->ccaes_xts_decrypt; |
57 | |
58 | if (!enc || !dec) { |
59 | panic("%s: xts mode not registered? enc=%p, dec=%p" , __FUNCTION__, enc, dec); |
60 | } |
61 | |
62 | /* Make sure the context size for the mode fits in the one we have */ |
63 | if ((enc->size > sizeof(xts->enc)) || (dec->size > sizeof(xts->dec))) { |
64 | panic("%s: inconsistent size for AES-XTS context" , __FUNCTION__); |
65 | } |
66 | |
67 | int rc = enc->init(enc, xts->enc, keylen, key1, key2); |
68 | rc |= dec->init(dec, xts->dec, keylen, key1, key2); |
69 | |
70 | return rc; |
71 | } |
72 | |
73 | int |
74 | xts_encrypt(const uint8_t *pt, unsigned long ptlen, |
75 | uint8_t *ct, |
76 | const uint8_t *iv, // this can be considered the sector IV for this use |
77 | symmetric_xts *xts) |
78 | { |
79 | const struct ccmode_xts *xtsenc = g_crypto_funcs->ccaes_xts_encrypt; |
80 | ccxts_tweak_decl(xtsenc->tweak_size, tweak); |
81 | |
82 | if (ptlen % 16) { |
83 | panic("xts encrypt not a multiple of block size" ); |
84 | } |
85 | |
86 | int rc = xtsenc->set_tweak(xts->enc, tweak, iv); |
87 | if (rc) { |
88 | return rc; |
89 | } |
90 | |
91 | xtsenc->xts(xts->enc, tweak, ptlen / 16, pt, ct); |
92 | return 0; |
93 | } |
94 | |
95 | int |
96 | xts_decrypt(const uint8_t *ct, unsigned long ptlen, |
97 | uint8_t *pt, |
98 | const uint8_t *iv, // this can be considered the sector IV for this use |
99 | symmetric_xts *xts) |
100 | { |
101 | const struct ccmode_xts *xtsdec = g_crypto_funcs->ccaes_xts_decrypt; |
102 | ccxts_tweak_decl(xtsdec->tweak_size, tweak); |
103 | |
104 | if (ptlen % 16) { |
105 | panic("xts decrypt not a multiple of block size" ); |
106 | } |
107 | |
108 | int rc = xtsdec->set_tweak(xts->dec, tweak, iv); |
109 | if (rc) { |
110 | return rc; |
111 | } |
112 | |
113 | xtsdec->xts(xts->dec, tweak, ptlen / 16, ct, pt); |
114 | return 0; |
115 | } |
116 | |
117 | void |
118 | xts_done(symmetric_xts *xts __unused) |
119 | { |
120 | cc_clear(len: sizeof(xts->enc), dst: xts->enc); |
121 | cc_clear(len: sizeof(xts->dec), dst: xts->dec); |
122 | } |
123 | |