xref: /openbsd/lib/libcrypto/aes/aes.c (revision 09b34817)
1 /* $OpenBSD: aes.c,v 1.4 2024/08/11 13:02:39 jsing Exp $ */
2 /* ====================================================================
3  * Copyright (c) 2002-2006 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    openssl-core@openssl.org.
26  *
27  * 5. Products derived from this software may not be called "OpenSSL"
28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  */
51 
52 #include <string.h>
53 
54 #include <openssl/aes.h>
55 #include <openssl/bio.h>
56 #include <openssl/modes.h>
57 
58 #include "crypto_arch.h"
59 
60 static const unsigned char aes_wrap_default_iv[] = {
61 	0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
62 };
63 
64 #ifdef HAVE_AES_CBC_ENCRYPT_INTERNAL
65 void aes_cbc_encrypt_internal(const unsigned char *in, unsigned char *out,
66     size_t len, const AES_KEY *key, unsigned char *ivec, const int enc);
67 
68 #else
69 static inline void
aes_cbc_encrypt_internal(const unsigned char * in,unsigned char * out,size_t len,const AES_KEY * key,unsigned char * ivec,const int enc)70 aes_cbc_encrypt_internal(const unsigned char *in, unsigned char *out,
71     size_t len, const AES_KEY *key, unsigned char *ivec, const int enc)
72 {
73 	if (enc)
74 		CRYPTO_cbc128_encrypt(in, out, len, key, ivec,
75 		    (block128_f)AES_encrypt);
76 	else
77 		CRYPTO_cbc128_decrypt(in, out, len, key, ivec,
78 		    (block128_f)AES_decrypt);
79 }
80 #endif
81 
82 void
AES_cbc_encrypt(const unsigned char * in,unsigned char * out,size_t len,const AES_KEY * key,unsigned char * ivec,const int enc)83 AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
84     size_t len, const AES_KEY *key, unsigned char *ivec, const int enc)
85 {
86 	aes_cbc_encrypt_internal(in, out, len, key, ivec, enc);
87 }
88 LCRYPTO_ALIAS(AES_cbc_encrypt);
89 
90 /*
91  * The input and output encrypted as though 128bit cfb mode is being
92  * used.  The extra state information to record how much of the
93  * 128bit block we have used is contained in *num;
94  */
95 
96 void
AES_cfb128_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,int * num,const int enc)97 AES_cfb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
98     const AES_KEY *key, unsigned char *ivec, int *num, const int enc)
99 {
100 	CRYPTO_cfb128_encrypt(in, out, length, key, ivec, num, enc,
101 	    (block128_f)AES_encrypt);
102 }
103 LCRYPTO_ALIAS(AES_cfb128_encrypt);
104 
105 /* N.B. This expects the input to be packed, MS bit first */
106 void
AES_cfb1_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,int * num,const int enc)107 AES_cfb1_encrypt(const unsigned char *in, unsigned char *out, size_t length,
108     const AES_KEY *key, unsigned char *ivec, int *num, const int enc)
109 {
110 	CRYPTO_cfb128_1_encrypt(in, out, length, key, ivec, num, enc,
111 	    (block128_f)AES_encrypt);
112 }
113 LCRYPTO_ALIAS(AES_cfb1_encrypt);
114 
115 void
AES_cfb8_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,int * num,const int enc)116 AES_cfb8_encrypt(const unsigned char *in, unsigned char *out, size_t length,
117     const AES_KEY *key, unsigned char *ivec, int *num, const int enc)
118 {
119 	CRYPTO_cfb128_8_encrypt(in, out, length, key, ivec, num, enc,
120 	    (block128_f)AES_encrypt);
121 }
122 LCRYPTO_ALIAS(AES_cfb8_encrypt);
123 
124 void
AES_ctr128_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char ivec[AES_BLOCK_SIZE],unsigned char ecount_buf[AES_BLOCK_SIZE],unsigned int * num)125 AES_ctr128_encrypt(const unsigned char *in, unsigned char *out,
126     size_t length, const AES_KEY *key, unsigned char ivec[AES_BLOCK_SIZE],
127     unsigned char ecount_buf[AES_BLOCK_SIZE], unsigned int *num)
128 {
129 	CRYPTO_ctr128_encrypt(in, out, length, key, ivec, ecount_buf, num,
130 	    (block128_f)AES_encrypt);
131 }
132 LCRYPTO_ALIAS(AES_ctr128_encrypt);
133 
134 void
AES_ecb_encrypt(const unsigned char * in,unsigned char * out,const AES_KEY * key,const int enc)135 AES_ecb_encrypt(const unsigned char *in, unsigned char *out,
136     const AES_KEY *key, const int enc)
137 {
138 	if (AES_ENCRYPT == enc)
139 		AES_encrypt(in, out, key);
140 	else
141 		AES_decrypt(in, out, key);
142 }
143 LCRYPTO_ALIAS(AES_ecb_encrypt);
144 
145 void
AES_ofb128_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,int * num)146 AES_ofb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
147     const AES_KEY *key, unsigned char *ivec, int *num)
148 {
149 	CRYPTO_ofb128_encrypt(in, out, length, key, ivec, num,
150 	    (block128_f)AES_encrypt);
151 }
152 LCRYPTO_ALIAS(AES_ofb128_encrypt);
153 
154 int
AES_wrap_key(AES_KEY * key,const unsigned char * iv,unsigned char * out,const unsigned char * in,unsigned int inlen)155 AES_wrap_key(AES_KEY *key, const unsigned char *iv, unsigned char *out,
156     const unsigned char *in, unsigned int inlen)
157 {
158 	unsigned char *A, B[16], *R;
159 	unsigned int i, j, t;
160 
161 	if ((inlen & 0x7) || (inlen < 16))
162 		return -1;
163 	A = B;
164 	t = 1;
165 	memmove(out + 8, in, inlen);
166 	if (!iv)
167 		iv = aes_wrap_default_iv;
168 
169 	memcpy(A, iv, 8);
170 
171 	for (j = 0; j < 6; j++) {
172 		R = out + 8;
173 		for (i = 0; i < inlen; i += 8, t++, R += 8) {
174 			memcpy(B + 8, R, 8);
175 			AES_encrypt(B, B, key);
176 			A[7] ^= (unsigned char)(t & 0xff);
177 			if (t > 0xff) {
178 				A[6] ^= (unsigned char)((t >> 8) & 0xff);
179 				A[5] ^= (unsigned char)((t >> 16) & 0xff);
180 				A[4] ^= (unsigned char)((t >> 24) & 0xff);
181 			}
182 			memcpy(R, B + 8, 8);
183 		}
184 	}
185 	memcpy(out, A, 8);
186 	return inlen + 8;
187 }
188 LCRYPTO_ALIAS(AES_wrap_key);
189 
190 int
AES_unwrap_key(AES_KEY * key,const unsigned char * iv,unsigned char * out,const unsigned char * in,unsigned int inlen)191 AES_unwrap_key(AES_KEY *key, const unsigned char *iv, unsigned char *out,
192     const unsigned char *in, unsigned int inlen)
193 {
194 	unsigned char *A, B[16], *R;
195 	unsigned int i, j, t;
196 
197 	if ((inlen & 0x7) || (inlen < 24))
198 		return -1;
199 	inlen -= 8;
200 	A = B;
201 	t = 6 * (inlen >> 3);
202 	memcpy(A, in, 8);
203 	memmove(out, in + 8, inlen);
204 	for (j = 0; j < 6; j++) {
205 		R = out + inlen - 8;
206 		for (i = 0; i < inlen; i += 8, t--, R -= 8) {
207 			A[7] ^= (unsigned char)(t & 0xff);
208 			if (t > 0xff) {
209 				A[6] ^= (unsigned char)((t >> 8) & 0xff);
210 				A[5] ^= (unsigned char)((t >> 16) & 0xff);
211 				A[4] ^= (unsigned char)((t >> 24) & 0xff);
212 			}
213 			memcpy(B + 8, R, 8);
214 			AES_decrypt(B, B, key);
215 			memcpy(R, B + 8, 8);
216 		}
217 	}
218 	if (!iv)
219 		iv = aes_wrap_default_iv;
220 	if (memcmp(A, iv, 8)) {
221 		explicit_bzero(out, inlen);
222 		return 0;
223 	}
224 	return inlen;
225 }
226 LCRYPTO_ALIAS(AES_unwrap_key);
227