1 /*
2  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project.
4  */
5 /* ====================================================================
6  * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  */
53 
54 #include <openssl/aes.h>
55 #include <openssl/mem.h>
56 
57 #include <string.h>
58 #include <stdlib.h>
59 
60 static const uint8_t default_iv[] = {
61     0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
62 };
63 
AES_wrap_key(AES_KEY * key,const uint8_t * iv,uint8_t * out,const uint8_t * in,unsigned int inlen)64 int AES_wrap_key(AES_KEY *key, const uint8_t *iv, uint8_t *out,
65                  const uint8_t *in, unsigned int inlen) {
66   uint8_t *A, B[16], *R;
67   unsigned int i, j, t;
68   if ((inlen & 0x7) || (inlen < 8)) return -1;
69   A = B;
70   t = 1;
71   memcpy(out + 8, in, inlen);
72   if (!iv) iv = default_iv;
73 
74   memcpy(A, iv, 8);
75 
76   for (j = 0; j < 6; j++) {
77     R = out + 8;
78     for (i = 0; i < inlen; i += 8, t++, R += 8) {
79       memcpy(B + 8, R, 8);
80       AES_encrypt(B, B, key);
81       A[7] ^= (uint8_t)(t & 0xff);
82       if (t > 0xff) {
83         A[6] ^= (uint8_t)((t >> 8) & 0xff);
84         A[5] ^= (uint8_t)((t >> 16) & 0xff);
85         A[4] ^= (uint8_t)((t >> 24) & 0xff);
86       }
87       memcpy(R, B + 8, 8);
88     }
89   }
90   memcpy(out, A, 8);
91   return inlen + 8;
92 }
93 
AES_unwrap_key(AES_KEY * key,const uint8_t * iv,uint8_t * out,const uint8_t * in,unsigned int inlen)94 int AES_unwrap_key(AES_KEY *key, const uint8_t *iv, uint8_t *out,
95                    const uint8_t *in, unsigned int inlen) {
96   uint8_t *A, B[16], *R;
97   unsigned int i, j, t;
98   inlen -= 8;
99   if (inlen & 0x7) return -1;
100   if (inlen < 8) return -1;
101   A = B;
102   t = 6 * (inlen >> 3);
103   memcpy(A, in, 8);
104   memcpy(out, in + 8, inlen);
105   for (j = 0; j < 6; j++) {
106     R = out + inlen - 8;
107     for (i = 0; i < inlen; i += 8, t--, R -= 8) {
108       A[7] ^= (uint8_t)(t & 0xff);
109       if (t > 0xff) {
110         A[6] ^= (uint8_t)((t >> 8) & 0xff);
111         A[5] ^= (uint8_t)((t >> 16) & 0xff);
112         A[4] ^= (uint8_t)((t >> 24) & 0xff);
113       }
114       memcpy(B + 8, R, 8);
115       AES_decrypt(B, B, key);
116       memcpy(R, B + 8, 8);
117     }
118   }
119   if (!iv) iv = default_iv;
120   if (memcmp(A, iv, 8)) {
121     OPENSSL_cleanse(out, inlen);
122     return 0;
123   }
124   return inlen;
125 }
126