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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