xref: /openbsd/lib/libcrypto/evp/e_rc4.c (revision 9bac3682)
1 /* $OpenBSD: e_rc4.c,v 1.20 2024/04/09 13:52:41 beck Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 #include <stdio.h>
60 
61 #include <openssl/opensslconf.h>
62 
63 #ifndef OPENSSL_NO_RC4
64 
65 #include <openssl/evp.h>
66 #include <openssl/objects.h>
67 #include <openssl/rc4.h>
68 
69 #include "evp_local.h"
70 
71 /* FIXME: surely this is available elsewhere? */
72 #define EVP_RC4_KEY_SIZE		16
73 
74 typedef struct {
75     RC4_KEY ks;	/* working key */
76 } EVP_RC4_KEY;
77 
78 #define data(ctx) ((EVP_RC4_KEY *)(ctx)->cipher_data)
79 
80 static int rc4_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
81     const unsigned char *iv, int enc);
82 static int rc4_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
83     const unsigned char *in, size_t inl);
84 
85 static const EVP_CIPHER r4_cipher = {
86 	.nid = NID_rc4,
87 	.block_size = 1,
88 	.key_len = EVP_RC4_KEY_SIZE,
89 	.iv_len = 0,
90 	.flags = EVP_CIPH_VARIABLE_LENGTH,
91 	.init = rc4_init_key,
92 	.do_cipher = rc4_cipher,
93 	.cleanup = NULL,
94 	.ctx_size = sizeof(EVP_RC4_KEY),
95 	.set_asn1_parameters = NULL,
96 	.get_asn1_parameters = NULL,
97 	.ctrl = NULL,
98 };
99 
100 static const EVP_CIPHER r4_40_cipher = {
101 	.nid = NID_rc4_40,
102 	.block_size = 1,
103 	.key_len = 5,
104 	.iv_len = 0,
105 	.flags = EVP_CIPH_VARIABLE_LENGTH,
106 	.init = rc4_init_key,
107 	.do_cipher = rc4_cipher,
108 	.cleanup = NULL,
109 	.ctx_size = sizeof(EVP_RC4_KEY),
110 	.set_asn1_parameters = NULL,
111 	.get_asn1_parameters = NULL,
112 	.ctrl = NULL,
113 };
114 
115 const EVP_CIPHER *
EVP_rc4(void)116 EVP_rc4(void)
117 {
118 	return (&r4_cipher);
119 }
120 LCRYPTO_ALIAS(EVP_rc4);
121 
122 const EVP_CIPHER *
EVP_rc4_40(void)123 EVP_rc4_40(void)
124 {
125 	return (&r4_40_cipher);
126 }
127 LCRYPTO_ALIAS(EVP_rc4_40);
128 
129 static int
rc4_init_key(EVP_CIPHER_CTX * ctx,const unsigned char * key,const unsigned char * iv,int enc)130 rc4_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
131     const unsigned char *iv, int enc)
132 {
133 	RC4_set_key(&data(ctx)->ks, EVP_CIPHER_CTX_key_length(ctx), key);
134 	return 1;
135 }
136 
137 static int
rc4_cipher(EVP_CIPHER_CTX * ctx,unsigned char * out,const unsigned char * in,size_t inl)138 rc4_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
139     const unsigned char *in, size_t inl)
140 {
141 	RC4(&data(ctx)->ks, inl, in, out);
142 	return 1;
143 }
144 #endif
145