crypto/evp/e_rc4_hmac_md5.c

   1 /*
   2  * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 <openssl/opensslconf.h>
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14
  15 #if !defined(OPENSSL_NO_RC4) && !defined(OPENSSL_NO_MD5)
  16
  17 # include <openssl/crypto.h>
  18 # include <openssl/evp.h>
  19 # include <openssl/objects.h>
  20 # include <openssl/rc4.h>
  21 # include <openssl/md5.h>
  22 # include "internal/evp_int.h"
  23
  24 typedef struct {
  25     RC4_KEY ks;
  26     MD5_CTX head, tail, md;
  27     size_t payload_length;
  28 } EVP_RC4_HMAC_MD5;
  29
  30 # define NO_PAYLOAD_LENGTH       ((size_t)-1)
  31
  32 void rc4_md5_enc(RC4_KEY *key, const void *in0, void *out,
  33                  MD5_CTX *ctx, const void *inp, size_t blocks);
  34
  35 # define data(ctx) ((EVP_RC4_HMAC_MD5 *)EVP_CIPHER_CTX_get_cipher_data(ctx))
  36
  37 static int rc4_hmac_md5_init_key(EVP_CIPHER_CTX *ctx,
  38                                  const unsigned char *inkey,
  39                                  const unsigned char *iv, int enc)
  40 {
  41     EVP_RC4_HMAC_MD5 *key = data(ctx);
  42
  43     RC4_set_key(&key->ks, EVP_CIPHER_CTX_key_length(ctx), inkey);
  44
  45     MD5_Init(&key->head);       /* handy when benchmarking */
  46     key->tail = key->head;
  47     key->md = key->head;
  48
  49     key->payload_length = NO_PAYLOAD_LENGTH;
  50
  51     return 1;
  52 }
  53
  54 # if     defined(RC4_ASM) && defined(MD5_ASM) &&     (     \
  55         defined(__x86_64)       || defined(__x86_64__)  || \
  56         defined(_M_AMD64)       || defined(_M_X64)      )
  57 #  define STITCHED_CALL
  58 # endif
  59
  60 # if !defined(STITCHED_CALL)
  61 #  define rc4_off 0
  62 #  define md5_off 0
  63 # endif
  64
  65 static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
  66                                const unsigned char *in, size_t len)
  67 {
  68     EVP_RC4_HMAC_MD5 *key = data(ctx);
  69 # if defined(STITCHED_CALL)
  70     size_t rc4_off = 32 - 1 - (key->ks.x & (32 - 1)), /* 32 is $MOD from
  71                                                        * rc4_md5-x86_64.pl */
  72         md5_off = MD5_CBLOCK - key->md.num, blocks;
  73     unsigned int l;
  74     extern unsigned int OPENSSL_ia32cap_P[];
  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
 176 static 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
 239 static 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
 258 const EVP_CIPHER *EVP_rc4_hmac_md5(void)
 259 {
 260     return &r4_hmac_md5_cipher;
 261 }
 262 #endif