e_rc4_hmac_md5.c revision 280304 
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    RC4_KEY ks;
73    MD5_CTX head, tail, md;
74    size_t payload_length;
75} EVP_RC4_HMAC_MD5;
76
77# define NO_PAYLOAD_LENGTH       ((size_t)-1)
78
79void rc4_md5_enc(RC4_KEY *key, const void *in0, void *out,
80                 MD5_CTX *ctx, const void *inp, size_t blocks);
81
82# define data(ctx) ((EVP_RC4_HMAC_MD5 *)(ctx)->cipher_data)
83
84static int rc4_hmac_md5_init_key(EVP_CIPHER_CTX *ctx,
85                                 const unsigned char *inkey,
86                                 const unsigned char *iv, int enc)
87{
88    EVP_RC4_HMAC_MD5 *key = data(ctx);
89
90    RC4_set_key(&key->ks, EVP_CIPHER_CTX_key_length(ctx), inkey);
91
92    MD5_Init(&key->head);       /* handy when benchmarking */
93    key->tail = key->head;
94    key->md = key->head;
95
96    key->payload_length = NO_PAYLOAD_LENGTH;
97
98    return 1;
99}
100
101# if     !defined(OPENSSL_NO_ASM) &&     ( \
102        defined(__x86_64)       || defined(__x86_64__)  || \
103        defined(_M_AMD64)       || defined(_M_X64)      || \
104        defined(__INTEL__)              ) && \
105        !(defined(__APPLE__) && defined(__MACH__))
106#  define STITCHED_CALL
107# endif
108
109# if !defined(STITCHED_CALL)
110#  define rc4_off 0
111#  define md5_off 0
112# endif
113
114static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
115                               const unsigned char *in, size_t len)
116{
117    EVP_RC4_HMAC_MD5 *key = data(ctx);
118# if defined(STITCHED_CALL)
119    size_t rc4_off = 32 - 1 - (key->ks.x & (32 - 1)), /* 32 is $MOD from
120                                                       * rc4_md5-x86_64.pl */
121        md5_off = MD5_CBLOCK - key->md.num, blocks;
122    unsigned int l;
123    extern unsigned int OPENSSL_ia32cap_P[];
124# endif
125    size_t plen = key->payload_length;
126
127    if (plen != NO_PAYLOAD_LENGTH && len != (plen + MD5_DIGEST_LENGTH))
128        return 0;
129
130    if (ctx->encrypt) {
131        if (plen == NO_PAYLOAD_LENGTH)
132            plen = len;
133# if defined(STITCHED_CALL)
134        /* cipher has to "fall behind" */
135        if (rc4_off > md5_off)
136            md5_off += MD5_CBLOCK;
137
138        if (plen > md5_off && (blocks = (plen - md5_off) / MD5_CBLOCK) &&
139            (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
140            MD5_Update(&key->md, in, md5_off);
141            RC4(&key->ks, rc4_off, in, out);
142
143            rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
144                        &key->md, in + md5_off, blocks);
145            blocks *= MD5_CBLOCK;
146            rc4_off += blocks;
147            md5_off += blocks;
148            key->md.Nh += blocks >> 29;
149            key->md.Nl += blocks <<= 3;
150            if (key->md.Nl < (unsigned int)blocks)
151                key->md.Nh++;
152        } else {
153            rc4_off = 0;
154            md5_off = 0;
155        }
156# endif
157        MD5_Update(&key->md, in + md5_off, plen - md5_off);
158
159        if (plen != len) {      /* "TLS" mode of operation */
160            if (in != out)
161                memcpy(out + rc4_off, in + rc4_off, plen - rc4_off);
162
163            /* calculate HMAC and append it to payload */
164            MD5_Final(out + plen, &key->md);
165            key->md = key->tail;
166            MD5_Update(&key->md, out + plen, MD5_DIGEST_LENGTH);
167            MD5_Final(out + plen, &key->md);
168            /* encrypt HMAC at once */
169            RC4(&key->ks, len - rc4_off, out + rc4_off, out + rc4_off);
170        } else {
171            RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
172        }
173    } else {
174        unsigned char mac[MD5_DIGEST_LENGTH];
175# if defined(STITCHED_CALL)
176        /* digest has to "fall behind" */
177        if (md5_off > rc4_off)
178            rc4_off += 2 * MD5_CBLOCK;
179        else
180            rc4_off += MD5_CBLOCK;
181
182        if (len > rc4_off && (blocks = (len - rc4_off) / MD5_CBLOCK) &&
183            (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
184            RC4(&key->ks, rc4_off, in, out);
185            MD5_Update(&key->md, out, md5_off);
186
187            rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
188                        &key->md, out + md5_off, blocks);
189            blocks *= MD5_CBLOCK;
190            rc4_off += blocks;
191            md5_off += blocks;
192            l = (key->md.Nl + (blocks << 3)) & 0xffffffffU;
193            if (l < key->md.Nl)
194                key->md.Nh++;
195            key->md.Nl = l;
196            key->md.Nh += blocks >> 29;
197        } else {
198            md5_off = 0;
199            rc4_off = 0;
200        }
201# endif
202        /* decrypt HMAC at once */
203        RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
204        if (plen != NO_PAYLOAD_LENGTH) { /* "TLS" mode of operation */
205            MD5_Update(&key->md, out + md5_off, plen - md5_off);
206
207            /* calculate HMAC and verify it */
208            MD5_Final(mac, &key->md);
209            key->md = key->tail;
210            MD5_Update(&key->md, mac, MD5_DIGEST_LENGTH);
211            MD5_Final(mac, &key->md);
212
213            if (memcmp(out + plen, mac, MD5_DIGEST_LENGTH))
214                return 0;
215        } else {
216            MD5_Update(&key->md, out + md5_off, len - md5_off);
217        }
218    }
219
220    key->payload_length = NO_PAYLOAD_LENGTH;
221
222    return 1;
223}
224
225static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
226                             void *ptr)
227{
228    EVP_RC4_HMAC_MD5 *key = data(ctx);
229
230    switch (type) {
231    case EVP_CTRL_AEAD_SET_MAC_KEY:
232        {
233            unsigned int i;
234            unsigned char hmac_key[64];
235
236            memset(hmac_key, 0, sizeof(hmac_key));
237
238            if (arg > (int)sizeof(hmac_key)) {
239                MD5_Init(&key->head);
240                MD5_Update(&key->head, ptr, arg);
241                MD5_Final(hmac_key, &key->head);
242            } else {
243                memcpy(hmac_key, ptr, arg);
244            }
245
246            for (i = 0; i < sizeof(hmac_key); i++)
247                hmac_key[i] ^= 0x36; /* ipad */
248            MD5_Init(&key->head);
249            MD5_Update(&key->head, hmac_key, sizeof(hmac_key));
250
251            for (i = 0; i < sizeof(hmac_key); i++)
252                hmac_key[i] ^= 0x36 ^ 0x5c; /* opad */
253            MD5_Init(&key->tail);
254            MD5_Update(&key->tail, hmac_key, sizeof(hmac_key));
255
256            return 1;
257        }
258    case EVP_CTRL_AEAD_TLS1_AAD:
259        {
260            unsigned char *p = ptr;
261            unsigned int len = p[arg - 2] << 8 | p[arg - 1];
262
263            if (!ctx->encrypt) {
264                len -= MD5_DIGEST_LENGTH;
265                p[arg - 2] = len >> 8;
266                p[arg - 1] = len;
267            }
268            key->payload_length = len;
269            key->md = key->head;
270            MD5_Update(&key->md, p, arg);
271
272            return MD5_DIGEST_LENGTH;
273        }
274    default:
275        return -1;
276    }
277}
278
279static EVP_CIPHER r4_hmac_md5_cipher = {
280# ifdef NID_rc4_hmac_md5
281    NID_rc4_hmac_md5,
282# else
283    NID_undef,
284# endif
285    1, EVP_RC4_KEY_SIZE, 0,
286    EVP_CIPH_STREAM_CIPHER | EVP_CIPH_VARIABLE_LENGTH |
287        EVP_CIPH_FLAG_AEAD_CIPHER,
288    rc4_hmac_md5_init_key,
289    rc4_hmac_md5_cipher,
290    NULL,
291    sizeof(EVP_RC4_HMAC_MD5),
292    NULL,
293    NULL,
294    rc4_hmac_md5_ctrl,
295    NULL
296};
297
298const EVP_CIPHER *EVP_rc4_hmac_md5(void)
299{
300    return (&r4_hmac_md5_cipher);
301}
302#endif
303