crypto/evp/e_rc4_hmac_md5.c

   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 /*
  11  * MD5 and RC4 low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <internal/cryptlib.h>
  17 #include <openssl/opensslconf.h>
  18
  19 #include <stdio.h>
  20 #include <string.h>
  21
  22 #if !defined(OPENSSL_NO_RC4) && !defined(OPENSSL_NO_MD5)
  23
  24 # include <openssl/crypto.h>
  25 # include <openssl/evp.h>
  26 # include <openssl/objects.h>
  27 # include <openssl/rc4.h>
  28 # include <openssl/md5.h>
  29 # include "crypto/evp.h"
  30
  31 typedef struct {
  32     RC4_KEY ks;
  33     MD5_CTX head, tail, md;
  34     size_t payload_length;
  35 } EVP_RC4_HMAC_MD5;
  36
  37 # define NO_PAYLOAD_LENGTH       ((size_t)-1)
  38
  39 void rc4_md5_enc(RC4_KEY *key, const void *in0, void *out,
  40                  MD5_CTX *ctx, const void *inp, size_t blocks);
  41
  42 # define data(ctx) ((EVP_RC4_HMAC_MD5 *)EVP_CIPHER_CTX_get_cipher_data(ctx))
  43
  44 static int rc4_hmac_md5_init_key(EVP_CIPHER_CTX *ctx,
  45                                  const unsigned char *inkey,
  46                                  const unsigned char *iv, int enc)
  47 {
  48     EVP_RC4_HMAC_MD5 *key = data(ctx);
  49
  50     RC4_set_key(&key->ks, EVP_CIPHER_CTX_key_length(ctx), inkey);
  51
  52     MD5_Init(&key->head);       /* handy when benchmarking */
  53     key->tail = key->head;
  54     key->md = key->head;
  55
  56     key->payload_length = NO_PAYLOAD_LENGTH;
  57
  58     return 1;
  59 }
  60
  61 # if     defined(RC4_ASM) && defined(MD5_ASM) &&     (     \
  62         defined(__x86_64)       || defined(__x86_64__)  || \
  63         defined(_M_AMD64)       || defined(_M_X64)      )
  64 #  define STITCHED_CALL
  65 # endif
  66
  67 # if !defined(STITCHED_CALL)
  68 #  define rc4_off 0
  69 #  define md5_off 0
  70 # endif
  71
  72 static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
  73                                const unsigned char *in, size_t len)
  74 {
  75     EVP_RC4_HMAC_MD5 *key = data(ctx);
  76 # if defined(STITCHED_CALL)
  77     size_t rc4_off = 32 - 1 - (key->ks.x & (32 - 1)), /* 32 is $MOD from
  78                                                        * rc4_md5-x86_64.pl */
  79         md5_off = MD5_CBLOCK - key->md.num, blocks;
  80     unsigned int l;
  81 # endif
  82     size_t plen = key->payload_length;
  83
  84     if (plen != NO_PAYLOAD_LENGTH && len != (plen + MD5_DIGEST_LENGTH))
  85         return 0;
  86
  87     if (EVP_CIPHER_CTX_encrypting(ctx)) {
  88         if (plen == NO_PAYLOAD_LENGTH)
  89             plen = len;
  90 # if defined(STITCHED_CALL)
  91         /* cipher has to "fall behind" */
  92         if (rc4_off > md5_off)
  93             md5_off += MD5_CBLOCK;
  94
  95         if (plen > md5_off && (blocks = (plen - md5_off) / MD5_CBLOCK) &&
  96             (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
  97             MD5_Update(&key->md, in, md5_off);
  98             RC4(&key->ks, rc4_off, in, out);
  99
 100             rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
 101                         &key->md, in + md5_off, blocks);
 102             blocks *= MD5_CBLOCK;
 103             rc4_off += blocks;
 104             md5_off += blocks;
 105             key->md.Nh += blocks >> 29;
 106             key->md.Nl += blocks <<= 3;
 107             if (key->md.Nl < (unsigned int)blocks)
 108                 key->md.Nh++;
 109         } else {
 110             rc4_off = 0;
 111             md5_off = 0;
 112         }
 113 # endif
 114         MD5_Update(&key->md, in + md5_off, plen - md5_off);
 115
 116         if (plen != len) {      /* "TLS" mode of operation */
 117             if (in != out)
 118                 memcpy(out + rc4_off, in + rc4_off, plen - rc4_off);
 119
 120             /* calculate HMAC and append it to payload */
 121             MD5_Final(out + plen, &key->md);
 122             key->md = key->tail;
 123             MD5_Update(&key->md, out + plen, MD5_DIGEST_LENGTH);
 124             MD5_Final(out + plen, &key->md);
 125             /* encrypt HMAC at once */
 126             RC4(&key->ks, len - rc4_off, out + rc4_off, out + rc4_off);
 127         } else {
 128             RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
 129         }
 130     } else {
 131         unsigned char mac[MD5_DIGEST_LENGTH];
 132 # if defined(STITCHED_CALL)
 133         /* digest has to "fall behind" */
 134         if (md5_off > rc4_off)
 135             rc4_off += 2 * MD5_CBLOCK;
 136         else
 137             rc4_off += MD5_CBLOCK;
 138
 139         if (len > rc4_off && (blocks = (len - rc4_off) / MD5_CBLOCK) &&
 140             (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
 141             RC4(&key->ks, rc4_off, in, out);
 142             MD5_Update(&key->md, out, md5_off);
 143
 144             rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
 145                         &key->md, out + md5_off, blocks);
 146             blocks *= MD5_CBLOCK;
 147             rc4_off += blocks;
 148             md5_off += blocks;
 149             l = (key->md.Nl + (blocks << 3)) & 0xffffffffU;
 150             if (l < key->md.Nl)
 151                 key->md.Nh++;
 152             key->md.Nl = l;
 153             key->md.Nh += blocks >> 29;
 154         } else {
 155             md5_off = 0;
 156             rc4_off = 0;
 157         }
 158 # endif
 159         /* decrypt HMAC at once */
 160         RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
 161         if (plen != NO_PAYLOAD_LENGTH) { /* "TLS" mode of operation */
 162             MD5_Update(&key->md, out + md5_off, plen - md5_off);
 163
 164             /* calculate HMAC and verify it */
 165             MD5_Final(mac, &key->md);
 166             key->md = key->tail;
 167             MD5_Update(&key->md, mac, MD5_DIGEST_LENGTH);
 168             MD5_Final(mac, &key->md);
 169
 170             if (CRYPTO_memcmp(out + plen, mac, MD5_DIGEST_LENGTH))
 171                 return 0;
 172         } else {
 173             MD5_Update(&key->md, out + md5_off, len - md5_off);
 174         }
 175     }
 176
 177     key->payload_length = NO_PAYLOAD_LENGTH;
 178
 179     return 1;
 180 }
 181
 182 static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
 183                              void *ptr)
 184 {
 185     EVP_RC4_HMAC_MD5 *key = data(ctx);
 186
 187     switch (type) {
 188     case EVP_CTRL_AEAD_SET_MAC_KEY:
 189         {
 190             unsigned int i;
 191             unsigned char hmac_key[64];
 192
 193             memset(hmac_key, 0, sizeof(hmac_key));
 194
 195             if (arg > (int)sizeof(hmac_key)) {
 196                 MD5_Init(&key->head);
 197                 MD5_Update(&key->head, ptr, arg);
 198                 MD5_Final(hmac_key, &key->head);
 199             } else {
 200                 memcpy(hmac_key, ptr, arg);
 201             }
 202
 203             for (i = 0; i < sizeof(hmac_key); i++)
 204                 hmac_key[i] ^= 0x36; /* ipad */
 205             MD5_Init(&key->head);
 206             MD5_Update(&key->head, hmac_key, sizeof(hmac_key));
 207
 208             for (i = 0; i < sizeof(hmac_key); i++)
 209                 hmac_key[i] ^= 0x36 ^ 0x5c; /* opad */
 210             MD5_Init(&key->tail);
 211             MD5_Update(&key->tail, hmac_key, sizeof(hmac_key));
 212
 213             OPENSSL_cleanse(hmac_key, sizeof(hmac_key));
 214
 215             return 1;
 216         }
 217     case EVP_CTRL_AEAD_TLS1_AAD:
 218         {
 219             unsigned char *p = ptr;
 220             unsigned int len;
 221
 222             if (arg != EVP_AEAD_TLS1_AAD_LEN)
 223                 return -1;
 224
 225             len = p[arg - 2] << 8 | p[arg - 1];
 226
 227             if (!EVP_CIPHER_CTX_encrypting(ctx)) {
 228                 if (len < MD5_DIGEST_LENGTH)
 229                     return -1;
 230                 len -= MD5_DIGEST_LENGTH;
 231                 p[arg - 2] = len >> 8;
 232                 p[arg - 1] = len;
 233             }
 234             key->payload_length = len;
 235             key->md = key->head;
 236             MD5_Update(&key->md, p, arg);
 237
 238             return MD5_DIGEST_LENGTH;
 239         }
 240     default:
 241         return -1;
 242     }
 243 }
 244
 245 static EVP_CIPHER r4_hmac_md5_cipher = {
 246 # ifdef NID_rc4_hmac_md5
 247     NID_rc4_hmac_md5,
 248 # else
 249     NID_undef,
 250 # endif
 251     1, EVP_RC4_KEY_SIZE, 0,
 252     EVP_CIPH_STREAM_CIPHER | EVP_CIPH_VARIABLE_LENGTH |
 253         EVP_CIPH_FLAG_AEAD_CIPHER,
 254     rc4_hmac_md5_init_key,
 255     rc4_hmac_md5_cipher,
 256     NULL,
 257     sizeof(EVP_RC4_HMAC_MD5),
 258     NULL,
 259     NULL,
 260     rc4_hmac_md5_ctrl,
 261     NULL
 262 };
 263
 264 const EVP_CIPHER *EVP_rc4_hmac_md5(void)
 265 {
 266     return &r4_hmac_md5_cipher;
 267 }
 268 #endif