xref: /openbsd/lib/libcrypto/aes/aes.c (revision 1bda4576)
1 /* $OpenBSD: aes.c,v 1.3 2024/03/30 05:14:12 joshua 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 static const unsigned char aes_wrap_default_iv[] = {
59 	0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
60 };
61 
62 #ifdef HAVE_AES_CBC_ENCRYPT_INTERNAL
63 void aes_cbc_encrypt_internal(const unsigned char *in, unsigned char *out,
64     size_t len, const AES_KEY *key, unsigned char *ivec, const int enc);
65 
66 #else
67 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)68 aes_cbc_encrypt_internal(const unsigned char *in, unsigned char *out,
69     size_t len, const AES_KEY *key, unsigned char *ivec, const int enc)
70 {
71 	if (enc)
72 		CRYPTO_cbc128_encrypt(in, out, len, key, ivec,
73 		    (block128_f)AES_encrypt);
74 	else
75 		CRYPTO_cbc128_decrypt(in, out, len, key, ivec,
76 		    (block128_f)AES_decrypt);
77 }
78 #endif
79 
80 void
AES_cbc_encrypt(const unsigned char * in,unsigned char * out,size_t len,const AES_KEY * key,unsigned char * ivec,const int enc)81 AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
82     size_t len, const AES_KEY *key, unsigned char *ivec, const int enc)
83 {
84 	aes_cbc_encrypt_internal(in, out, len, key, ivec, enc);
85 }
86 LCRYPTO_ALIAS(AES_cbc_encrypt);
87 
88 /*
89  * The input and output encrypted as though 128bit cfb mode is being
90  * used.  The extra state information to record how much of the
91  * 128bit block we have used is contained in *num;
92  */
93 
94 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)95 AES_cfb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
96     const AES_KEY *key, unsigned char *ivec, int *num, const int enc)
97 {
98 	CRYPTO_cfb128_encrypt(in, out, length, key, ivec, num, enc,
99 	    (block128_f)AES_encrypt);
100 }
101 LCRYPTO_ALIAS(AES_cfb128_encrypt);
102 
103 /* N.B. This expects the input to be packed, MS bit first */
104 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)105 AES_cfb1_encrypt(const unsigned char *in, unsigned char *out, size_t length,
106     const AES_KEY *key, unsigned char *ivec, int *num, const int enc)
107 {
108 	CRYPTO_cfb128_1_encrypt(in, out, length, key, ivec, num, enc,
109 	    (block128_f)AES_encrypt);
110 }
111 LCRYPTO_ALIAS(AES_cfb1_encrypt);
112 
113 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)114 AES_cfb8_encrypt(const unsigned char *in, unsigned char *out, size_t length,
115     const AES_KEY *key, unsigned char *ivec, int *num, const int enc)
116 {
117 	CRYPTO_cfb128_8_encrypt(in, out, length, key, ivec, num, enc,
118 	    (block128_f)AES_encrypt);
119 }
120 LCRYPTO_ALIAS(AES_cfb8_encrypt);
121 
122 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)123 AES_ctr128_encrypt(const unsigned char *in, unsigned char *out,
124     size_t length, const AES_KEY *key, unsigned char ivec[AES_BLOCK_SIZE],
125     unsigned char ecount_buf[AES_BLOCK_SIZE], unsigned int *num)
126 {
127 	CRYPTO_ctr128_encrypt(in, out, length, key, ivec, ecount_buf, num,
128 	    (block128_f)AES_encrypt);
129 }
130 LCRYPTO_ALIAS(AES_ctr128_encrypt);
131 
132 void
AES_ecb_encrypt(const unsigned char * in,unsigned char * out,const AES_KEY * key,const int enc)133 AES_ecb_encrypt(const unsigned char *in, unsigned char *out,
134     const AES_KEY *key, const int enc)
135 {
136 	if (AES_ENCRYPT == enc)
137 		AES_encrypt(in, out, key);
138 	else
139 		AES_decrypt(in, out, key);
140 }
141 LCRYPTO_ALIAS(AES_ecb_encrypt);
142 
143 void
AES_ofb128_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,int * num)144 AES_ofb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
145     const AES_KEY *key, unsigned char *ivec, int *num)
146 {
147 	CRYPTO_ofb128_encrypt(in, out, length, key, ivec, num,
148 	    (block128_f)AES_encrypt);
149 }
150 LCRYPTO_ALIAS(AES_ofb128_encrypt);
151 
152 int
AES_wrap_key(AES_KEY * key,const unsigned char * iv,unsigned char * out,const unsigned char * in,unsigned int inlen)153 AES_wrap_key(AES_KEY *key, const unsigned char *iv, unsigned char *out,
154     const unsigned char *in, unsigned int inlen)
155 {
156 	unsigned char *A, B[16], *R;
157 	unsigned int i, j, t;
158 
159 	if ((inlen & 0x7) || (inlen < 16))
160 		return -1;
161 	A = B;
162 	t = 1;
163 	memmove(out + 8, in, inlen);
164 	if (!iv)
165 		iv = aes_wrap_default_iv;
166 
167 	memcpy(A, iv, 8);
168 
169 	for (j = 0; j < 6; j++) {
170 		R = out + 8;
171 		for (i = 0; i < inlen; i += 8, t++, R += 8) {
172 			memcpy(B + 8, R, 8);
173 			AES_encrypt(B, B, key);
174 			A[7] ^= (unsigned char)(t & 0xff);
175 			if (t > 0xff) {
176 				A[6] ^= (unsigned char)((t >> 8) & 0xff);
177 				A[5] ^= (unsigned char)((t >> 16) & 0xff);
178 				A[4] ^= (unsigned char)((t >> 24) & 0xff);
179 			}
180 			memcpy(R, B + 8, 8);
181 		}
182 	}
183 	memcpy(out, A, 8);
184 	return inlen + 8;
185 }
186 LCRYPTO_ALIAS(AES_wrap_key);
187 
188 int
AES_unwrap_key(AES_KEY * key,const unsigned char * iv,unsigned char * out,const unsigned char * in,unsigned int inlen)189 AES_unwrap_key(AES_KEY *key, const unsigned char *iv, unsigned char *out,
190     const unsigned char *in, unsigned int inlen)
191 {
192 	unsigned char *A, B[16], *R;
193 	unsigned int i, j, t;
194 
195 	if ((inlen & 0x7) || (inlen < 24))
196 		return -1;
197 	inlen -= 8;
198 	A = B;
199 	t = 6 * (inlen >> 3);
200 	memcpy(A, in, 8);
201 	memmove(out, in + 8, inlen);
202 	for (j = 0; j < 6; j++) {
203 		R = out + inlen - 8;
204 		for (i = 0; i < inlen; i += 8, t--, R -= 8) {
205 			A[7] ^= (unsigned char)(t & 0xff);
206 			if (t > 0xff) {
207 				A[6] ^= (unsigned char)((t >> 8) & 0xff);
208 				A[5] ^= (unsigned char)((t >> 16) & 0xff);
209 				A[4] ^= (unsigned char)((t >> 24) & 0xff);
210 			}
211 			memcpy(B + 8, R, 8);
212 			AES_decrypt(B, B, key);
213 			memcpy(R, B + 8, 8);
214 		}
215 	}
216 	if (!iv)
217 		iv = aes_wrap_default_iv;
218 	if (memcmp(A, iv, 8)) {
219 		explicit_bzero(out, inlen);
220 		return 0;
221 	}
222 	return inlen;
223 }
224 LCRYPTO_ALIAS(AES_unwrap_key);
225