1 /* ====================================================================
2 * Copyright (c) 2001-2011 The OpenSSL Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in
13 * the documentation and/or other materials provided with the
14 * distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 * software must display the following acknowledgment:
18 * "This product includes software developed by the OpenSSL Project
19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 * endorse or promote products derived from this software without
23 * prior written permission. For written permission, please contact
24 * openssl-core@openssl.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 * nor may "OpenSSL" appear in their names without prior written
28 * permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 * acknowledgment:
32 * "This product includes software developed by the OpenSSL Project
33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ==================================================================== */
48
49 #include <openssl/aes.h>
50
51 #include <limits.h>
52 #include <string.h>
53
54 #include <openssl/mem.h>
55
56 #include "../../internal.h"
57
58
59 // kDefaultIV is the default IV value given in RFC 3394, 2.2.3.1.
60 static const uint8_t kDefaultIV[] = {
61 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6,
62 };
63
64 static const unsigned kBound = 6;
65
AES_wrap_key(const AES_KEY * key,const uint8_t * iv,uint8_t * out,const uint8_t * in,size_t in_len)66 int AES_wrap_key(const AES_KEY *key, const uint8_t *iv, uint8_t *out,
67 const uint8_t *in, size_t in_len) {
68 // See RFC 3394, section 2.2.1. Additionally, note that section 2 requires the
69 // plaintext be at least two 8-byte blocks.
70
71 if (in_len > INT_MAX - 8 || in_len < 16 || in_len % 8 != 0) {
72 return -1;
73 }
74
75 if (iv == NULL) {
76 iv = kDefaultIV;
77 }
78
79 OPENSSL_memmove(out + 8, in, in_len);
80 uint8_t A[AES_BLOCK_SIZE];
81 OPENSSL_memcpy(A, iv, 8);
82
83 size_t n = in_len / 8;
84
85 for (unsigned j = 0; j < kBound; j++) {
86 for (size_t i = 1; i <= n; i++) {
87 OPENSSL_memcpy(A + 8, out + 8 * i, 8);
88 AES_encrypt(A, A, key);
89
90 uint32_t t = (uint32_t)(n * j + i);
91 A[7] ^= t & 0xff;
92 A[6] ^= (t >> 8) & 0xff;
93 A[5] ^= (t >> 16) & 0xff;
94 A[4] ^= (t >> 24) & 0xff;
95 OPENSSL_memcpy(out + 8 * i, A + 8, 8);
96 }
97 }
98
99 OPENSSL_memcpy(out, A, 8);
100 return (int)in_len + 8;
101 }
102
AES_unwrap_key(const AES_KEY * key,const uint8_t * iv,uint8_t * out,const uint8_t * in,size_t in_len)103 int AES_unwrap_key(const AES_KEY *key, const uint8_t *iv, uint8_t *out,
104 const uint8_t *in, size_t in_len) {
105 // See RFC 3394, section 2.2.2. Additionally, note that section 2 requires the
106 // plaintext be at least two 8-byte blocks, so the ciphertext must be at least
107 // three blocks.
108
109 if (in_len > INT_MAX || in_len < 24 || in_len % 8 != 0) {
110 return -1;
111 }
112
113 if (iv == NULL) {
114 iv = kDefaultIV;
115 }
116
117 uint8_t A[AES_BLOCK_SIZE];
118 OPENSSL_memcpy(A, in, 8);
119 OPENSSL_memmove(out, in + 8, in_len - 8);
120
121 size_t n = (in_len / 8) - 1;
122
123 for (unsigned j = kBound - 1; j < kBound; j--) {
124 for (size_t i = n; i > 0; i--) {
125 uint32_t t = (uint32_t)(n * j + i);
126 A[7] ^= t & 0xff;
127 A[6] ^= (t >> 8) & 0xff;
128 A[5] ^= (t >> 16) & 0xff;
129 A[4] ^= (t >> 24) & 0xff;
130 OPENSSL_memcpy(A + 8, out + 8 * (i - 1), 8);
131 AES_decrypt(A, A, key);
132 OPENSSL_memcpy(out + 8 * (i - 1), A + 8, 8);
133 }
134 }
135
136 if (CRYPTO_memcmp(A, iv, 8) != 0) {
137 return -1;
138 }
139
140 return (int)in_len - 8;
141 }
142