providers/implementations/ciphers/cipher_rc4_hmac_md5_hw.c

   1 /*
   2  * Copyright 2019 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 /* RC4_HMAC_MD5 cipher implementation */
  11
  12 /*
  13  * MD5 and RC4 low level APIs are deprecated for public use, but still ok for
  14  * internal use.
  15  */
  16 #include "internal/deprecated.h"
  17
  18 #include "cipher_rc4_hmac_md5.h"
  19
  20 #define NO_PAYLOAD_LENGTH ((size_t)-1)
  21
  22 #if defined(RC4_ASM)                                                           \
  23     && defined(MD5_ASM)                                                        \
  24     && (defined(__x86_64)                                                      \
  25         || defined(__x86_64__)                                                 \
  26         || defined(_M_AMD64)                                                   \
  27         || defined(_M_X64))
  28 # define STITCHED_CALL
  29 # define MOD 32 /* 32 is $MOD from rc4_md5-x86_64.pl */
  30 #else
  31 # define rc4_off 0
  32 # define md5_off 0
  33 #endif
  34
  35 static int cipher_hw_rc4_hmac_md5_initkey(PROV_CIPHER_CTX *bctx,
  36                                           const uint8_t *key, size_t keylen)
  37 {
  38     PROV_RC4_HMAC_MD5_CTX *ctx = (PROV_RC4_HMAC_MD5_CTX *)bctx;
  39
  40     RC4_set_key(&ctx->ks.ks, keylen, key);
  41     MD5_Init(&ctx->head);       /* handy when benchmarking */
  42     ctx->tail = ctx->head;
  43     ctx->md = ctx->head;
  44     ctx->payload_length = NO_PAYLOAD_LENGTH;
  45     return 1;
  46 }
  47
  48 static int cipher_hw_rc4_hmac_md5_cipher(PROV_CIPHER_CTX *bctx,
  49                                          unsigned char *out,
  50                                          const unsigned char *in, size_t len)
  51 {
  52     PROV_RC4_HMAC_MD5_CTX *ctx = (PROV_RC4_HMAC_MD5_CTX *)bctx;
  53     RC4_KEY *ks = &ctx->ks.ks;
  54
  55 #if defined(STITCHED_CALL)
  56     size_t rc4_off = MOD - 1 - (ks->x & (MOD - 1));
  57     size_t md5_off = MD5_CBLOCK - ctx->md.num, blocks;
  58     unsigned int l;
  59 #endif
  60     size_t plen = ctx->payload_length;
  61
  62     if (plen != NO_PAYLOAD_LENGTH && len != (plen + MD5_DIGEST_LENGTH))
  63         return 0;
  64
  65     if (ctx->base.enc) {
  66         if (plen == NO_PAYLOAD_LENGTH)
  67             plen = len;
  68 #if defined(STITCHED_CALL)
  69         /* cipher has to "fall behind" */
  70         if (rc4_off > md5_off)
  71             md5_off += MD5_CBLOCK;
  72
  73         if (plen > md5_off
  74                 && (blocks = (plen - md5_off) / MD5_CBLOCK)
  75                 && (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
  76             MD5_Update(&ctx->md, in, md5_off);
  77             RC4(ks, rc4_off, in, out);
  78
  79             rc4_md5_enc(ks, in + rc4_off, out + rc4_off,
  80                         &ctx->md, in + md5_off, blocks);
  81             blocks *= MD5_CBLOCK;
  82             rc4_off += blocks;
  83             md5_off += blocks;
  84             ctx->md.Nh += blocks >> 29;
  85             ctx->md.Nl += blocks <<= 3;
  86             if (ctx->md.Nl < (unsigned int)blocks)
  87                 ctx->md.Nh++;
  88         } else {
  89             rc4_off = 0;
  90             md5_off = 0;
  91         }
  92 #endif
  93         MD5_Update(&ctx->md, in + md5_off, plen - md5_off);
  94
  95         if (plen != len) {      /* "TLS" mode of operation */
  96             if (in != out)
  97                 memcpy(out + rc4_off, in + rc4_off, plen - rc4_off);
  98
  99             /* calculate HMAC and append it to payload */
 100             MD5_Final(out + plen, &ctx->md);
 101             ctx->md = ctx->tail;
 102             MD5_Update(&ctx->md, out + plen, MD5_DIGEST_LENGTH);
 103             MD5_Final(out + plen, &ctx->md);
 104             /* encrypt HMAC at once */
 105             RC4(ks, len - rc4_off, out + rc4_off, out + rc4_off);
 106         } else {
 107             RC4(ks, len - rc4_off, in + rc4_off, out + rc4_off);
 108         }
 109     } else {
 110         unsigned char mac[MD5_DIGEST_LENGTH];
 111
 112 #if defined(STITCHED_CALL)
 113         /* digest has to "fall behind" */
 114         if (md5_off > rc4_off)
 115             rc4_off += 2 * MD5_CBLOCK;
 116         else
 117             rc4_off += MD5_CBLOCK;
 118
 119         if (len > rc4_off
 120                 && (blocks = (len - rc4_off) / MD5_CBLOCK)
 121                 && (OPENSSL_ia32cap_P[0] & (1 << 20)) == 0) {
 122             RC4(ks, rc4_off, in, out);
 123             MD5_Update(&ctx->md, out, md5_off);
 124
 125             rc4_md5_enc(ks, in + rc4_off, out + rc4_off,
 126                         &ctx->md, out + md5_off, blocks);
 127             blocks *= MD5_CBLOCK;
 128             rc4_off += blocks;
 129             md5_off += blocks;
 130             l = (ctx->md.Nl + (blocks << 3)) & 0xffffffffU;
 131             if (l < ctx->md.Nl)
 132                 ctx->md.Nh++;
 133             ctx->md.Nl = l;
 134             ctx->md.Nh += blocks >> 29;
 135         } else {
 136             md5_off = 0;
 137             rc4_off = 0;
 138         }
 139 #endif
 140         /* decrypt HMAC at once */
 141         RC4(ks, len - rc4_off, in + rc4_off, out + rc4_off);
 142         if (plen != NO_PAYLOAD_LENGTH) {
 143             /* "TLS" mode of operation */
 144             MD5_Update(&ctx->md, out + md5_off, plen - md5_off);
 145
 146             /* calculate HMAC and verify it */
 147             MD5_Final(mac, &ctx->md);
 148             ctx->md = ctx->tail;
 149             MD5_Update(&ctx->md, mac, MD5_DIGEST_LENGTH);
 150             MD5_Final(mac, &ctx->md);
 151
 152             if (CRYPTO_memcmp(out + plen, mac, MD5_DIGEST_LENGTH))
 153                 return 0;
 154         } else {
 155             MD5_Update(&ctx->md, out + md5_off, len - md5_off);
 156         }
 157     }
 158
 159     ctx->payload_length = NO_PAYLOAD_LENGTH;
 160
 161     return 1;
 162 }
 163
 164 static int cipher_hw_rc4_hmac_md5_tls_init(PROV_CIPHER_CTX *bctx,
 165                                            unsigned char *aad, size_t aad_len)
 166 {
 167     PROV_RC4_HMAC_MD5_CTX *ctx = (PROV_RC4_HMAC_MD5_CTX *)bctx;
 168     unsigned int len;
 169
 170     if (aad_len != EVP_AEAD_TLS1_AAD_LEN)
 171         return 0;
 172
 173     len = aad[aad_len - 2] << 8 | aad[aad_len - 1];
 174
 175     if (!bctx->enc) {
 176         if (len < MD5_DIGEST_LENGTH)
 177             return 0;
 178         len -= MD5_DIGEST_LENGTH;
 179         aad[aad_len - 2] = len >> 8;
 180         aad[aad_len - 1] = len;
 181     }
 182     ctx->payload_length = len;
 183     ctx->md = ctx->head;
 184     MD5_Update(&ctx->md, aad, aad_len);
 185
 186     return MD5_DIGEST_LENGTH;
 187 }
 188
 189 static void cipher_hw_rc4_hmac_md5_init_mackey(PROV_CIPHER_CTX *bctx,
 190                                                const unsigned char *key,
 191                                                size_t len)
 192 {
 193     PROV_RC4_HMAC_MD5_CTX *ctx = (PROV_RC4_HMAC_MD5_CTX *)bctx;
 194     unsigned int i;
 195     unsigned char hmac_key[64];
 196
 197     memset(hmac_key, 0, sizeof(hmac_key));
 198
 199     if (len > (int)sizeof(hmac_key)) {
 200         MD5_Init(&ctx->head);
 201         MD5_Update(&ctx->head, key, len);
 202         MD5_Final(hmac_key, &ctx->head);
 203     } else {
 204         memcpy(hmac_key, key, len);
 205     }
 206
 207     for (i = 0; i < sizeof(hmac_key); i++)
 208         hmac_key[i] ^= 0x36; /* ipad */
 209     MD5_Init(&ctx->head);
 210     MD5_Update(&ctx->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(&ctx->tail);
 215     MD5_Update(&ctx->tail, hmac_key, sizeof(hmac_key));
 216
 217     OPENSSL_cleanse(hmac_key, sizeof(hmac_key));
 218 }
 219
 220 static const PROV_CIPHER_HW_RC4_HMAC_MD5 rc4_hmac_md5_hw = {
 221     {
 222       cipher_hw_rc4_hmac_md5_initkey,
 223       cipher_hw_rc4_hmac_md5_cipher
 224     },
 225     cipher_hw_rc4_hmac_md5_tls_init,
 226     cipher_hw_rc4_hmac_md5_init_mackey
 227 };
 228 const PROV_CIPHER_HW *PROV_CIPHER_HW_rc4_hmac_md5(size_t keybits)
 229 {
 230     return (PROV_CIPHER_HW *)&rc4_hmac_md5_hw;
 231 }