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 
  71 typedef 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 
  80 void 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 
  85 static 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 
 116 static 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 
 220 static 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 
 275 static 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 
 294 const EVP_CIPHER *EVP_rc4_hmac_md5(void)
 295         {
 296         return(&r4_hmac_md5_cipher);
 297         }
 298 #endif