1 /* $OpenBSD: aes_wrap.c,v 1.12 2018/11/07 18:31:16 tb Exp $ */
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 <string.h>
55
56 #include <openssl/aes.h>
57 #include <openssl/bio.h>
58
59 static const unsigned char default_iv[] = {
60 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
61 };
62
63 int
AES_wrap_key(AES_KEY * key,const unsigned char * iv,unsigned char * out,const unsigned char * in,unsigned int inlen)64 AES_wrap_key(AES_KEY *key, const unsigned char *iv, unsigned char *out,
65 const unsigned char *in, unsigned int inlen)
66 {
67 unsigned char *A, B[16], *R;
68 unsigned int i, j, t;
69
70 if ((inlen & 0x7) || (inlen < 16))
71 return -1;
72 A = B;
73 t = 1;
74 memmove(out + 8, in, inlen);
75 if (!iv)
76 iv = default_iv;
77
78 memcpy(A, iv, 8);
79
80 for (j = 0; j < 6; j++) {
81 R = out + 8;
82 for (i = 0; i < inlen; i += 8, t++, R += 8) {
83 memcpy(B + 8, R, 8);
84 AES_encrypt(B, B, key);
85 A[7] ^= (unsigned char)(t & 0xff);
86 if (t > 0xff) {
87 A[6] ^= (unsigned char)((t >> 8) & 0xff);
88 A[5] ^= (unsigned char)((t >> 16) & 0xff);
89 A[4] ^= (unsigned char)((t >> 24) & 0xff);
90 }
91 memcpy(R, B + 8, 8);
92 }
93 }
94 memcpy(out, A, 8);
95 return inlen + 8;
96 }
97
98 int
AES_unwrap_key(AES_KEY * key,const unsigned char * iv,unsigned char * out,const unsigned char * in,unsigned int inlen)99 AES_unwrap_key(AES_KEY *key, const unsigned char *iv, unsigned char *out,
100 const unsigned char *in, unsigned int inlen)
101 {
102 unsigned char *A, B[16], *R;
103 unsigned int i, j, t;
104
105 if ((inlen & 0x7) || (inlen < 24))
106 return -1;
107 inlen -= 8;
108 A = B;
109 t = 6 * (inlen >> 3);
110 memcpy(A, in, 8);
111 memmove(out, in + 8, inlen);
112 for (j = 0; j < 6; j++) {
113 R = out + inlen - 8;
114 for (i = 0; i < inlen; i += 8, t--, R -= 8) {
115 A[7] ^= (unsigned char)(t & 0xff);
116 if (t > 0xff) {
117 A[6] ^= (unsigned char)((t >> 8) & 0xff);
118 A[5] ^= (unsigned char)((t >> 16) & 0xff);
119 A[4] ^= (unsigned char)((t >> 24) & 0xff);
120 }
121 memcpy(B + 8, R, 8);
122 AES_decrypt(B, B, key);
123 memcpy(R, B + 8, 8);
124 }
125 }
126 if (!iv)
127 iv = default_iv;
128 if (memcmp(A, iv, 8)) {
129 explicit_bzero(out, inlen);
130 return 0;
131 }
132 return inlen;
133 }
134