crypto/evp/e_rc4_hmac_md5.c

   1 /*
   2  * Copyright 2011-2021 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     const int keylen = EVP_CIPHER_CTX_key_length(ctx);
  50
  51     if (keylen <= 0)
  52         return 0;
  53
  54     RC4_set_key(&key->ks, keylen, inkey);
  55
  56     MD5_Init(&key->head);       /* handy when benchmarking */
  57     key->tail = key->head;
  58     key->md = key->head;
  59
  60     key->payload_length = NO_PAYLOAD_LENGTH;
  61
  62     return 1;
  63 }
  64
  65 # if     defined(RC4_ASM) && defined(MD5_ASM) &&     (     \
  66         defined(__x86_64)       || defined(__x86_64__)  || \
  67         defined(_M_AMD64)       || defined(_M_X64)      )
  68 #  define STITCHED_CALL
  69 # endif
  70
  71 # if !defined(STITCHED_CALL)
  72 #  define rc4_off 0
  73 #  define md5_off 0
  74 # endif
  75
  76 static int rc4_hmac_md5_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
  77                                const unsigned char *in, size_t len)
  78 {
  79     EVP_RC4_HMAC_MD5 *key = data(ctx);
  80 # if defined(STITCHED_CALL)
  81     size_t rc4_off = 32 - 1 - (key->ks.x & (32 - 1)), /* 32 is $MOD from
  82                                                        * rc4_md5-x86_64.pl */
  83         md5_off = MD5_CBLOCK - key->md.num, blocks;
  84     unsigned int l;
  85 # endif
  86     size_t plen = key->payload_length;
  87
  88     if (plen != NO_PAYLOAD_LENGTH && len != (plen + MD5_DIGEST_LENGTH))
  89         return 0;
  90
  91     if (EVP_CIPHER_CTX_encrypting(ctx)) {
  92         if (plen == NO_PAYLOAD_LENGTH)
  93             plen = len;
  94 # if defined(STITCHED_CALL)
  95         /* cipher has to "fall behind" */
  96         if (rc4_off > md5_off)
  97             md5_off += MD5_CBLOCK;
  98
  99         if (plen > md5_off && (blocks = (plen - md5_off) / MD5_CBLOCK) &&
 100             (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
 101             MD5_Update(&key->md, in, md5_off);
 102             RC4(&key->ks, rc4_off, in, out);
 103
 104             rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
 105                         &key->md, in + md5_off, blocks);
 106             blocks *= MD5_CBLOCK;
 107             rc4_off += blocks;
 108             md5_off += blocks;
 109             key->md.Nh += blocks >> 29;
 110             key->md.Nl += blocks <<= 3;
 111             if (key->md.Nl < (unsigned int)blocks)
 112                 key->md.Nh++;
 113         } else {
 114             rc4_off = 0;
 115             md5_off = 0;
 116         }
 117 # endif
 118         MD5_Update(&key->md, in + md5_off, plen - md5_off);
 119
 120         if (plen != len) {      /* "TLS" mode of operation */
 121             if (in != out)
 122                 memcpy(out + rc4_off, in + rc4_off, plen - rc4_off);
 123
 124             /* calculate HMAC and append it to payload */
 125             MD5_Final(out + plen, &key->md);
 126             key->md = key->tail;
 127             MD5_Update(&key->md, out + plen, MD5_DIGEST_LENGTH);
 128             MD5_Final(out + plen, &key->md);
 129             /* encrypt HMAC at once */
 130             RC4(&key->ks, len - rc4_off, out + rc4_off, out + rc4_off);
 131         } else {
 132             RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
 133         }
 134     } else {
 135         unsigned char mac[MD5_DIGEST_LENGTH];
 136 # if defined(STITCHED_CALL)
 137         /* digest has to "fall behind" */
 138         if (md5_off > rc4_off)
 139             rc4_off += 2 * MD5_CBLOCK;
 140         else
 141             rc4_off += MD5_CBLOCK;
 142
 143         if (len > rc4_off && (blocks = (len - rc4_off) / MD5_CBLOCK) &&
 144             (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
 145             RC4(&key->ks, rc4_off, in, out);
 146             MD5_Update(&key->md, out, md5_off);
 147
 148             rc4_md5_enc(&key->ks, in + rc4_off, out + rc4_off,
 149                         &key->md, out + md5_off, blocks);
 150             blocks *= MD5_CBLOCK;
 151             rc4_off += blocks;
 152             md5_off += blocks;
 153             l = (key->md.Nl + (blocks << 3)) & 0xffffffffU;
 154             if (l < key->md.Nl)
 155                 key->md.Nh++;
 156             key->md.Nl = l;
 157             key->md.Nh += blocks >> 29;
 158         } else {
 159             md5_off = 0;
 160             rc4_off = 0;
 161         }
 162 # endif
 163         /* decrypt HMAC at once */
 164         RC4(&key->ks, len - rc4_off, in + rc4_off, out + rc4_off);
 165         if (plen != NO_PAYLOAD_LENGTH) { /* "TLS" mode of operation */
 166             MD5_Update(&key->md, out + md5_off, plen - md5_off);
 167
 168             /* calculate HMAC and verify it */
 169             MD5_Final(mac, &key->md);
 170             key->md = key->tail;
 171             MD5_Update(&key->md, mac, MD5_DIGEST_LENGTH);
 172             MD5_Final(mac, &key->md);
 173
 174             if (CRYPTO_memcmp(out + plen, mac, MD5_DIGEST_LENGTH))
 175                 return 0;
 176         } else {
 177             MD5_Update(&key->md, out + md5_off, len - md5_off);
 178         }
 179     }
 180
 181     key->payload_length = NO_PAYLOAD_LENGTH;
 182
 183     return 1;
 184 }
 185
 186 static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
 187                              void *ptr)
 188 {
 189     EVP_RC4_HMAC_MD5 *key = data(ctx);
 190
 191     switch (type) {
 192     case EVP_CTRL_AEAD_SET_MAC_KEY:
 193         {
 194             unsigned int i;
 195             unsigned char hmac_key[64];
 196
 197             memset(hmac_key, 0, sizeof(hmac_key));
 198
 199             if (arg > (int)sizeof(hmac_key)) {
 200                 MD5_Init(&key->head);
 201                 MD5_Update(&key->head, ptr, arg);
 202                 MD5_Final(hmac_key, &key->head);
 203             } else {
 204                 memcpy(hmac_key, ptr, arg);
 205             }
 206
 207             for (i = 0; i < sizeof(hmac_key); i++)
 208                 hmac_key[i] ^= 0x36; /* ipad */
 209             MD5_Init(&key->head);
 210             MD5_Update(&key->head, hmac_key, sizeof(hmac_key));
 211
 212             for (i = 0; i < sizeof(hmac_key); i++)
 213                 hmac_key[i] ^= 0x36 ^ 0x5c; /* opad */
 214             MD5_Init(&key->tail);
 215             MD5_Update(&key->tail, hmac_key, sizeof(hmac_key));
 216
 217             OPENSSL_cleanse(hmac_key, sizeof(hmac_key));
 218
 219             return 1;
 220         }
 221     case EVP_CTRL_AEAD_TLS1_AAD:
 222         {
 223             unsigned char *p = ptr;
 224             unsigned int len;
 225
 226             if (arg != EVP_AEAD_TLS1_AAD_LEN)
 227                 return -1;
 228
 229             len = p[arg - 2] << 8 | p[arg - 1];
 230
 231             if (!EVP_CIPHER_CTX_encrypting(ctx)) {
 232                 if (len < MD5_DIGEST_LENGTH)
 233                     return -1;
 234                 len -= MD5_DIGEST_LENGTH;
 235                 p[arg - 2] = len >> 8;
 236                 p[arg - 1] = len;
 237             }
 238             key->payload_length = len;
 239             key->md = key->head;
 240             MD5_Update(&key->md, p, arg);
 241
 242             return MD5_DIGEST_LENGTH;
 243         }
 244     default:
 245         return -1;
 246     }
 247 }
 248
 249 static EVP_CIPHER r4_hmac_md5_cipher = {
 250 # ifdef NID_rc4_hmac_md5
 251     NID_rc4_hmac_md5,
 252 # else
 253     NID_undef,
 254 # endif
 255     1, EVP_RC4_KEY_SIZE, 0,
 256     EVP_CIPH_STREAM_CIPHER | EVP_CIPH_VARIABLE_LENGTH |
 257         EVP_CIPH_FLAG_AEAD_CIPHER,
 258     rc4_hmac_md5_init_key,
 259     rc4_hmac_md5_cipher,
 260     NULL,
 261     sizeof(EVP_RC4_HMAC_MD5),
 262     NULL,
 263     NULL,
 264     rc4_hmac_md5_ctrl,
 265     NULL
 266 };
 267
 268 const EVP_CIPHER *EVP_rc4_hmac_md5(void)
 269 {
 270     return &r4_hmac_md5_cipher;
 271 }
 272 #endif