e_rc4_hmac_md5.c revision 306195 
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/crypto.h>
58# include <openssl/evp.h>
59# include <openssl/objects.h>
60# include <openssl/rc4.h>
61# include <openssl/md5.h>
62
63# ifndef EVP_CIPH_FLAG_AEAD_CIPHER
64#  define EVP_CIPH_FLAG_AEAD_CIPHER       0x200000
65#  define EVP_CTRL_AEAD_TLS1_AAD          0x16
66#  define EVP_CTRL_AEAD_SET_MAC_KEY       0x17
67# endif
68
69/* FIXME: surely this is available elsewhere? */
70# define EVP_RC4_KEY_SIZE                16
71
72typedef struct {
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), inkey);
92
93    MD5_Init(&key->head);       /* handy when benchmarking */
94    key->tail = key->head;
95    key->md = key->head;
96
97    key->payload_length = NO_PAYLOAD_LENGTH;
98
99    return 1;
100}
101
102# if     defined(RC4_ASM) && defined(MD5_ASM) &&     (	   \
103        defined(__x86_64)       || defined(__x86_64__)  || \
104        defined(_M_AMD64)       || defined(_M_X64)      || \
105        defined(__INTEL__)              ) && \
106        !(defined(__APPLE__) && defined(__MACH__))
107#  define STITCHED_CALL
108# endif
109
110# if !defined(STITCHED_CALL)
111#  define rc4_off 0
112#  define md5_off 0
113# endif
114
115static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
116                               const unsigned char *in, size_t len)
117{
118    EVP_RC4_HMAC_MD5 *key = data(ctx);
119# if defined(STITCHED_CALL)
120    size_t rc4_off = 32 - 1 - (key->ks.x & (32 - 1)), /* 32 is $MOD from
121                                                       * rc4_md5-x86_64.pl */
122        md5_off = MD5_CBLOCK - key->md.num, blocks;
123    unsigned int l;
124    extern unsigned int OPENSSL_ia32cap_P[];
125# endif
126    size_t plen = key->payload_length;
127
128    if (plen != NO_PAYLOAD_LENGTH && len != (plen + MD5_DIGEST_LENGTH))
129        return 0;
130
131    if (ctx->encrypt) {
132        if (plen == NO_PAYLOAD_LENGTH)
133            plen = len;
134# if defined(STITCHED_CALL)
135        /* cipher has to "fall behind" */
136        if (rc4_off > md5_off)
137            md5_off += MD5_CBLOCK;
138
139        if (plen > md5_off && (blocks = (plen - md5_off) / MD5_CBLOCK) &&
140            (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
141            MD5_Update(&key->md, in, md5_off);
142            RC4(&key->ks, rc4_off, in, out);
143
144            rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
145                        &key->md, in + md5_off, blocks);
146            blocks *= MD5_CBLOCK;
147            rc4_off += blocks;
148            md5_off += blocks;
149            key->md.Nh += blocks >> 29;
150            key->md.Nl += blocks <<= 3;
151            if (key->md.Nl < (unsigned int)blocks)
152                key->md.Nh++;
153        } else {
154            rc4_off = 0;
155            md5_off = 0;
156        }
157# endif
158        MD5_Update(&key->md, in + md5_off, plen - md5_off);
159
160        if (plen != len) {      /* "TLS" mode of operation */
161            if (in != out)
162                memcpy(out + rc4_off, in + rc4_off, plen - rc4_off);
163
164            /* calculate HMAC and append it to payload */
165            MD5_Final(out + plen, &key->md);
166            key->md = key->tail;
167            MD5_Update(&key->md, out + plen, MD5_DIGEST_LENGTH);
168            MD5_Final(out + plen, &key->md);
169            /* encrypt HMAC at once */
170            RC4(&key->ks, len - rc4_off, out + rc4_off, out + rc4_off);
171        } else {
172            RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
173        }
174    } else {
175        unsigned char mac[MD5_DIGEST_LENGTH];
176# if defined(STITCHED_CALL)
177        /* digest has to "fall behind" */
178        if (md5_off > rc4_off)
179            rc4_off += 2 * MD5_CBLOCK;
180        else
181            rc4_off += MD5_CBLOCK;
182
183        if (len > rc4_off && (blocks = (len - rc4_off) / MD5_CBLOCK) &&
184            (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
185            RC4(&key->ks, rc4_off, in, out);
186            MD5_Update(&key->md, out, md5_off);
187
188            rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
189                        &key->md, out + md5_off, blocks);
190            blocks *= MD5_CBLOCK;
191            rc4_off += blocks;
192            md5_off += blocks;
193            l = (key->md.Nl + (blocks << 3)) & 0xffffffffU;
194            if (l < key->md.Nl)
195                key->md.Nh++;
196            key->md.Nl = l;
197            key->md.Nh += blocks >> 29;
198        } else {
199            md5_off = 0;
200            rc4_off = 0;
201        }
202# endif
203        /* decrypt HMAC at once */
204        RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
205        if (plen != NO_PAYLOAD_LENGTH) { /* "TLS" mode of operation */
206            MD5_Update(&key->md, out + md5_off, plen - md5_off);
207
208            /* calculate HMAC and verify it */
209            MD5_Final(mac, &key->md);
210            key->md = key->tail;
211            MD5_Update(&key->md, mac, MD5_DIGEST_LENGTH);
212            MD5_Final(mac, &key->md);
213
214            if (CRYPTO_memcmp(out + plen, mac, MD5_DIGEST_LENGTH))
215                return 0;
216        } else {
217            MD5_Update(&key->md, out + md5_off, len - md5_off);
218        }
219    }
220
221    key->payload_length = NO_PAYLOAD_LENGTH;
222
223    return 1;
224}
225
226static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
227                             void *ptr)
228{
229    EVP_RC4_HMAC_MD5 *key = data(ctx);
230
231    switch (type) {
232    case EVP_CTRL_AEAD_SET_MAC_KEY:
233        {
234            unsigned int i;
235            unsigned char hmac_key[64];
236
237            memset(hmac_key, 0, sizeof(hmac_key));
238
239            if (arg > (int)sizeof(hmac_key)) {
240                MD5_Init(&key->head);
241                MD5_Update(&key->head, ptr, arg);
242                MD5_Final(hmac_key, &key->head);
243            } else {
244                memcpy(hmac_key, ptr, arg);
245            }
246
247            for (i = 0; i < sizeof(hmac_key); i++)
248                hmac_key[i] ^= 0x36; /* ipad */
249            MD5_Init(&key->head);
250            MD5_Update(&key->head, hmac_key, sizeof(hmac_key));
251
252            for (i = 0; i < sizeof(hmac_key); i++)
253                hmac_key[i] ^= 0x36 ^ 0x5c; /* opad */
254            MD5_Init(&key->tail);
255            MD5_Update(&key->tail, hmac_key, sizeof(hmac_key));
256
257            OPENSSL_cleanse(hmac_key, sizeof(hmac_key));
258
259            return 1;
260        }
261    case EVP_CTRL_AEAD_TLS1_AAD:
262        {
263            unsigned char *p = ptr;
264            unsigned int len;
265
266            if (arg != EVP_AEAD_TLS1_AAD_LEN)
267                return -1;
268
269            len = p[arg - 2] << 8 | p[arg - 1];
270
271            if (!ctx->encrypt) {
272                len -= MD5_DIGEST_LENGTH;
273                p[arg - 2] = len >> 8;
274                p[arg - 1] = len;
275            }
276            key->payload_length = len;
277            key->md = key->head;
278            MD5_Update(&key->md, p, arg);
279
280            return MD5_DIGEST_LENGTH;
281        }
282    default:
283        return -1;
284    }
285}
286
287static EVP_CIPHER r4_hmac_md5_cipher = {
288# ifdef NID_rc4_hmac_md5
289    NID_rc4_hmac_md5,
290# else
291    NID_undef,
292# endif
293    1, EVP_RC4_KEY_SIZE, 0,
294    EVP_CIPH_STREAM_CIPHER | EVP_CIPH_VARIABLE_LENGTH |
295        EVP_CIPH_FLAG_AEAD_CIPHER,
296    rc4_hmac_md5_init_key,
297    rc4_hmac_md5_cipher,
298    NULL,
299    sizeof(EVP_RC4_HMAC_MD5),
300    NULL,
301    NULL,
302    rc4_hmac_md5_ctrl,
303    NULL
304};
305
306const EVP_CIPHER *EVP_rc4_hmac_md5(void)
307{
308    return (&r4_hmac_md5_cipher);
309}
310#endif
311