1/*
2 * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <internal/cryptlib.h>
11#include <openssl/opensslconf.h>
12
13#include <stdio.h>
14#include <string.h>
15
16#if !defined(OPENSSL_NO_RC4) && !defined(OPENSSL_NO_MD5)
17
18# include <openssl/crypto.h>
19# include <openssl/evp.h>
20# include <openssl/objects.h>
21# include <openssl/rc4.h>
22# include <openssl/md5.h>
23# include "crypto/evp.h"
24
25typedef struct {
26 RC4_KEY ks;
27 MD5_CTX head, tail, md;
28 size_t payload_length;
29} EVP_RC4_HMAC_MD5;
30
31# define NO_PAYLOAD_LENGTH ((size_t)-1)
32
33void rc4_md5_enc(RC4_KEY *key, const void *in0, void *out,
34 MD5_CTX *ctx, const void *inp, size_t blocks);
35
36# define data(ctx) ((EVP_RC4_HMAC_MD5 *)EVP_CIPHER_CTX_get_cipher_data(ctx))
37
38static int rc4_hmac_md5_init_key(EVP_CIPHER_CTX *ctx,
39 const unsigned char *inkey,
40 const unsigned char *iv, int enc)
41{
42 EVP_RC4_HMAC_MD5 *key = data(ctx);
43
44 RC4_set_key(&key->ks, EVP_CIPHER_CTX_key_length(ctx), inkey);
45
46 MD5_Init(&key->head); /* handy when benchmarking */
47 key->tail = key->head;
48 key->md = key->head;
49
50 key->payload_length = NO_PAYLOAD_LENGTH;
51
52 return 1;
53}
54
55# if defined(RC4_ASM) && defined(MD5_ASM) && ( \
56 defined(__x86_64) || defined(__x86_64__) || \
57 defined(_M_AMD64) || defined(_M_X64) )
58# define STITCHED_CALL
59# endif
60
61# if !defined(STITCHED_CALL)
62# define rc4_off 0
63# define md5_off 0
64# endif
65
66static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
67 const unsigned char *in, size_t len)
68{
69 EVP_RC4_HMAC_MD5 *key = data(ctx);
70# if defined(STITCHED_CALL)
71 size_t rc4_off = 32 - 1 - (key->ks.x & (32 - 1)), /* 32 is $MOD from
72 * rc4_md5-x86_64.pl */
73 md5_off = MD5_CBLOCK - key->md.num, blocks;
74 unsigned int l;
75# endif
76 size_t plen = key->payload_length;
77
78 if (plen != NO_PAYLOAD_LENGTH && len != (plen + MD5_DIGEST_LENGTH))
79 return 0;
80
81 if (EVP_CIPHER_CTX_encrypting(ctx)) {
82 if (plen == NO_PAYLOAD_LENGTH)
83 plen = len;
84# if defined(STITCHED_CALL)
85 /* cipher has to "fall behind" */
86 if (rc4_off > md5_off)
87 md5_off += MD5_CBLOCK;
88
89 if (plen > md5_off && (blocks = (plen - md5_off) / MD5_CBLOCK) &&
90 (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
91 MD5_Update(&key->md, in, md5_off);
92 RC4(&key->ks, rc4_off, in, out);
93
94 rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
95 &key->md, in + md5_off, blocks);
96 blocks *= MD5_CBLOCK;
97 rc4_off += blocks;
98 md5_off += blocks;
99 key->md.Nh += blocks >> 29;
100 key->md.Nl += blocks <<= 3;
101 if (key->md.Nl < (unsigned int)blocks)
102 key->md.Nh++;
103 } else {
104 rc4_off = 0;
105 md5_off = 0;
106 }
107# endif
108 MD5_Update(&key->md, in + md5_off, plen - md5_off);
109
110 if (plen != len) { /* "TLS" mode of operation */
111 if (in != out)
112 memcpy(out + rc4_off, in + rc4_off, plen - rc4_off);
113
114 /* calculate HMAC and append it to payload */
115 MD5_Final(out + plen, &key->md);
116 key->md = key->tail;
117 MD5_Update(&key->md, out + plen, MD5_DIGEST_LENGTH);
118 MD5_Final(out + plen, &key->md);
119 /* encrypt HMAC at once */
120 RC4(&key->ks, len - rc4_off, out + rc4_off, out + rc4_off);
121 } else {
122 RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
123 }
124 } else {
125 unsigned char mac[MD5_DIGEST_LENGTH];
126# if defined(STITCHED_CALL)
127 /* digest has to "fall behind" */
128 if (md5_off > rc4_off)
129 rc4_off += 2 * MD5_CBLOCK;
130 else
131 rc4_off += MD5_CBLOCK;
132
133 if (len > rc4_off && (blocks = (len - rc4_off) / MD5_CBLOCK) &&
134 (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
135 RC4(&key->ks, rc4_off, in, out);
136 MD5_Update(&key->md, out, md5_off);
137
138 rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
139 &key->md, out + md5_off, blocks);
140 blocks *= MD5_CBLOCK;
141 rc4_off += blocks;
142 md5_off += blocks;
143 l = (key->md.Nl + (blocks << 3)) & 0xffffffffU;
144 if (l < key->md.Nl)
145 key->md.Nh++;
146 key->md.Nl = l;
147 key->md.Nh += blocks >> 29;
148 } else {
149 md5_off = 0;
150 rc4_off = 0;
151 }
152# endif
153 /* decrypt HMAC at once */
154 RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
155 if (plen != NO_PAYLOAD_LENGTH) { /* "TLS" mode of operation */
156 MD5_Update(&key->md, out + md5_off, plen - md5_off);
157
158 /* calculate HMAC and verify it */
159 MD5_Final(mac, &key->md);
160 key->md = key->tail;
161 MD5_Update(&key->md, mac, MD5_DIGEST_LENGTH);
162 MD5_Final(mac, &key->md);
163
164 if (CRYPTO_memcmp(out + plen, mac, MD5_DIGEST_LENGTH))
165 return 0;
166 } else {
167 MD5_Update(&key->md, out + md5_off, len - md5_off);
168 }
169 }
170
171 key->payload_length = NO_PAYLOAD_LENGTH;
172
173 return 1;
174}
175
176static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
177 void *ptr)
178{
179 EVP_RC4_HMAC_MD5 *key = data(ctx);
180
181 switch (type) {
182 case EVP_CTRL_AEAD_SET_MAC_KEY:
183 {
184 unsigned int i;
185 unsigned char hmac_key[64];
186
187 memset(hmac_key, 0, sizeof(hmac_key));
188
189 if (arg > (int)sizeof(hmac_key)) {
190 MD5_Init(&key->head);
191 MD5_Update(&key->head, ptr, arg);
192 MD5_Final(hmac_key, &key->head);
193 } else {
194 memcpy(hmac_key, ptr, arg);
195 }
196
197 for (i = 0; i < sizeof(hmac_key); i++)
198 hmac_key[i] ^= 0x36; /* ipad */
199 MD5_Init(&key->head);
200 MD5_Update(&key->head, hmac_key, sizeof(hmac_key));
201
202 for (i = 0; i < sizeof(hmac_key); i++)
203 hmac_key[i] ^= 0x36 ^ 0x5c; /* opad */
204 MD5_Init(&key->tail);
205 MD5_Update(&key->tail, hmac_key, sizeof(hmac_key));
206
207 OPENSSL_cleanse(hmac_key, sizeof(hmac_key));
208
209 return 1;
210 }
211 case EVP_CTRL_AEAD_TLS1_AAD:
212 {
213 unsigned char *p = ptr;
214 unsigned int len;
215
216 if (arg != EVP_AEAD_TLS1_AAD_LEN)
217 return -1;
218
219 len = p[arg - 2] << 8 | p[arg - 1];
220
221 if (!EVP_CIPHER_CTX_encrypting(ctx)) {
222 if (len < MD5_DIGEST_LENGTH)
223 return -1;
224 len -= MD5_DIGEST_LENGTH;
225 p[arg - 2] = len >> 8;
226 p[arg - 1] = len;
227 }
228 key->payload_length = len;
229 key->md = key->head;
230 MD5_Update(&key->md, p, arg);
231
232 return MD5_DIGEST_LENGTH;
233 }
234 default:
235 return -1;
236 }
237}
238
239static EVP_CIPHER r4_hmac_md5_cipher = {
240# ifdef NID_rc4_hmac_md5
241 NID_rc4_hmac_md5,
242# else
243 NID_undef,
244# endif
245 1, EVP_RC4_KEY_SIZE, 0,
246 EVP_CIPH_STREAM_CIPHER | EVP_CIPH_VARIABLE_LENGTH |
247 EVP_CIPH_FLAG_AEAD_CIPHER,
248 rc4_hmac_md5_init_key,
249 rc4_hmac_md5_cipher,
250 NULL,
251 sizeof(EVP_RC4_HMAC_MD5),
252 NULL,
253 NULL,
254 rc4_hmac_md5_ctrl,
255 NULL
256};
257
258const EVP_CIPHER *EVP_rc4_hmac_md5(void)
259{
260 return &r4_hmac_md5_cipher;
261}
262#endif
263