1/* ====================================================================
2 * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in
13 *    the documentation and/or other materials provided with the
14 *    distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 *    software must display the following acknowledgment:
18 *    "This product includes software developed by the OpenSSL Project
19 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 *    endorse or promote products derived from this software without
23 *    prior written permission. For written permission, please contact
24 *    licensing@OpenSSL.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 *    nor may "OpenSSL" appear in their names without prior written
28 *    permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 *    acknowledgment:
32 *    "This product includes software developed by the OpenSSL Project
33 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
48 */
49
50#include <openssl/opensslconf.h>
51
52#include <stdio.h>
53#include <string.h>
54
55#if !defined(OPENSSL_NO_RC4) && !defined(OPENSSL_NO_MD5)
56
57#include <openssl/evp.h>
58#include <openssl/objects.h>
59#include <openssl/rc4.h>
60#include <openssl/md5.h>
61
62#ifndef EVP_CIPH_FLAG_AEAD_CIPHER
63#define EVP_CIPH_FLAG_AEAD_CIPHER	0x200000
64#define EVP_CTRL_AEAD_TLS1_AAD		0x16
65#define EVP_CTRL_AEAD_SET_MAC_KEY	0x17
66#endif
67
68/* FIXME: surely this is available elsewhere? */
69#define EVP_RC4_KEY_SIZE		16
70
71typedef struct
72    {
73    RC4_KEY		ks;
74    MD5_CTX		head,tail,md;
75    size_t		payload_length;
76    } EVP_RC4_HMAC_MD5;
77
78#define NO_PAYLOAD_LENGTH	((size_t)-1)
79
80void rc4_md5_enc (RC4_KEY *key, const void *in0, void *out,
81		MD5_CTX *ctx,const void *inp,size_t blocks);
82
83#define data(ctx) ((EVP_RC4_HMAC_MD5 *)(ctx)->cipher_data)
84
85static int rc4_hmac_md5_init_key(EVP_CIPHER_CTX *ctx,
86			const unsigned char *inkey,
87			const unsigned char *iv, int enc)
88	{
89	EVP_RC4_HMAC_MD5 *key = data(ctx);
90
91	RC4_set_key(&key->ks,EVP_CIPHER_CTX_key_length(ctx),
92		    inkey);
93
94	MD5_Init(&key->head);	/* handy when benchmarking */
95	key->tail = key->head;
96	key->md   = key->head;
97
98	key->payload_length = NO_PAYLOAD_LENGTH;
99
100	return 1;
101	}
102
103#if	!defined(OPENSSL_NO_ASM) &&	( \
104	defined(__x86_64)	|| defined(__x86_64__)	|| \
105	defined(_M_AMD64)	|| defined(_M_X64)	|| \
106	defined(__INTEL__)		) && \
107	!(defined(__APPLE__) && defined(__MACH__))
108#define	STITCHED_CALL
109#endif
110
111#if !defined(STITCHED_CALL)
112#define	rc4_off 0
113#define	md5_off 0
114#endif
115
116static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
117		      const unsigned char *in, size_t len)
118	{
119	EVP_RC4_HMAC_MD5 *key = data(ctx);
120#if defined(STITCHED_CALL)
121	size_t	rc4_off = 32-1-(key->ks.x&(32-1)),	/* 32 is $MOD from rc4_md5-x86_64.pl */
122		md5_off = MD5_CBLOCK-key->md.num,
123		blocks;
124	unsigned int l;
125	extern unsigned int OPENSSL_ia32cap_P[];
126#endif
127	size_t	plen = key->payload_length;
128
129	if (plen!=NO_PAYLOAD_LENGTH && len!=(plen+MD5_DIGEST_LENGTH)) return 0;
130
131	if (ctx->encrypt) {
132		if (plen==NO_PAYLOAD_LENGTH) plen = len;
133#if defined(STITCHED_CALL)
134		/* cipher has to "fall behind" */
135		if (rc4_off>md5_off) md5_off+=MD5_CBLOCK;
136
137		if (plen>md5_off && (blocks=(plen-md5_off)/MD5_CBLOCK) &&
138		    (OPENSSL_ia32cap_P[0]&(1<<20))==0) {
139			MD5_Update(&key->md,in,md5_off);
140			RC4(&key->ks,rc4_off,in,out);
141
142			rc4_md5_enc(&key->ks,in+rc4_off,out+rc4_off,
143				&key->md,in+md5_off,blocks);
144			blocks *= MD5_CBLOCK;
145			rc4_off += blocks;
146			md5_off += blocks;
147			key->md.Nh += blocks>>29;
148			key->md.Nl += blocks<<=3;
149			if (key->md.Nl<(unsigned int)blocks) key->md.Nh++;
150		} else {
151			rc4_off = 0;
152			md5_off = 0;
153		}
154#endif
155		MD5_Update(&key->md,in+md5_off,plen-md5_off);
156
157		if (plen!=len) {	/* "TLS" mode of operation */
158			if (in!=out)
159				memcpy(out+rc4_off,in+rc4_off,plen-rc4_off);
160
161			/* calculate HMAC and append it to payload */
162			MD5_Final(out+plen,&key->md);
163			key->md = key->tail;
164			MD5_Update(&key->md,out+plen,MD5_DIGEST_LENGTH);
165			MD5_Final(out+plen,&key->md);
166			/* encrypt HMAC at once */
167			RC4(&key->ks,len-rc4_off,out+rc4_off,out+rc4_off);
168		} else {
169			RC4(&key->ks,len-rc4_off,in+rc4_off,out+rc4_off);
170		}
171	} else {
172		unsigned char mac[MD5_DIGEST_LENGTH];
173#if defined(STITCHED_CALL)
174		/* digest has to "fall behind" */
175		if (md5_off>rc4_off)	rc4_off += 2*MD5_CBLOCK;
176		else			rc4_off += MD5_CBLOCK;
177
178		if (len>rc4_off && (blocks=(len-rc4_off)/MD5_CBLOCK) &&
179		    (OPENSSL_ia32cap_P[0]&(1<<20))==0) {
180			RC4(&key->ks,rc4_off,in,out);
181			MD5_Update(&key->md,out,md5_off);
182
183			rc4_md5_enc(&key->ks,in+rc4_off,out+rc4_off,
184				&key->md,out+md5_off,blocks);
185			blocks *= MD5_CBLOCK;
186			rc4_off += blocks;
187			md5_off += blocks;
188			l = (key->md.Nl+(blocks<<3))&0xffffffffU;
189			if (l<key->md.Nl) key->md.Nh++;
190			key->md.Nl  = l;
191			key->md.Nh += blocks>>29;
192		} else {
193			md5_off=0;
194			rc4_off=0;
195		}
196#endif
197		/* decrypt HMAC at once */
198		RC4(&key->ks,len-rc4_off,in+rc4_off,out+rc4_off);
199		if (plen!=NO_PAYLOAD_LENGTH) {	/* "TLS" mode of operation */
200			MD5_Update(&key->md,out+md5_off,plen-md5_off);
201
202			/* calculate HMAC and verify it */
203			MD5_Final(mac,&key->md);
204			key->md = key->tail;
205			MD5_Update(&key->md,mac,MD5_DIGEST_LENGTH);
206			MD5_Final(mac,&key->md);
207
208			if (memcmp(out+plen,mac,MD5_DIGEST_LENGTH))
209				return 0;
210		} else {
211			MD5_Update(&key->md,out+md5_off,len-md5_off);
212		}
213	}
214
215	key->payload_length = NO_PAYLOAD_LENGTH;
216
217	return 1;
218	}
219
220static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
221	{
222	EVP_RC4_HMAC_MD5 *key = data(ctx);
223
224	switch (type)
225		{
226	case EVP_CTRL_AEAD_SET_MAC_KEY:
227		{
228		unsigned int  i;
229		unsigned char hmac_key[64];
230
231		memset (hmac_key,0,sizeof(hmac_key));
232
233		if (arg > (int)sizeof(hmac_key)) {
234			MD5_Init(&key->head);
235			MD5_Update(&key->head,ptr,arg);
236			MD5_Final(hmac_key,&key->head);
237		} else {
238			memcpy(hmac_key,ptr,arg);
239		}
240
241		for (i=0;i<sizeof(hmac_key);i++)
242			hmac_key[i] ^= 0x36;		/* ipad */
243		MD5_Init(&key->head);
244		MD5_Update(&key->head,hmac_key,sizeof(hmac_key));
245
246		for (i=0;i<sizeof(hmac_key);i++)
247			hmac_key[i] ^= 0x36^0x5c;	/* opad */
248		MD5_Init(&key->tail);
249		MD5_Update(&key->tail,hmac_key,sizeof(hmac_key));
250
251		return 1;
252		}
253	case EVP_CTRL_AEAD_TLS1_AAD:
254		{
255		unsigned char *p=ptr;
256		unsigned int   len=p[arg-2]<<8|p[arg-1];
257
258		if (!ctx->encrypt)
259			{
260			len -= MD5_DIGEST_LENGTH;
261			p[arg-2] = len>>8;
262			p[arg-1] = len;
263			}
264		key->payload_length=len;
265		key->md = key->head;
266		MD5_Update(&key->md,p,arg);
267
268		return MD5_DIGEST_LENGTH;
269		}
270	default:
271		return -1;
272		}
273	}
274
275static EVP_CIPHER r4_hmac_md5_cipher=
276	{
277#ifdef NID_rc4_hmac_md5
278	NID_rc4_hmac_md5,
279#else
280	NID_undef,
281#endif
282	1,EVP_RC4_KEY_SIZE,0,
283	EVP_CIPH_STREAM_CIPHER|EVP_CIPH_VARIABLE_LENGTH|EVP_CIPH_FLAG_AEAD_CIPHER,
284	rc4_hmac_md5_init_key,
285	rc4_hmac_md5_cipher,
286	NULL,
287	sizeof(EVP_RC4_HMAC_MD5),
288	NULL,
289	NULL,
290	rc4_hmac_md5_ctrl,
291	NULL
292	};
293
294const EVP_CIPHER *EVP_rc4_hmac_md5(void)
295	{
296	return(&r4_hmac_md5_cipher);
297	}
298#endif
299