src/core/or/relay_crypto_st.h

   1 /* Copyright (c) 2001 Matej Pfajfar.
   2  * Copyright (c) 2001-2004, Roger Dingledine.
   3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   4  * Copyright (c) 2007-2021, The Tor Project, Inc. */
   5 /* See LICENSE for licensing information */
   6
   7 /**
   8  * @file relay_crypto_st.h
   9  * @brief Relay-cell encryption state structure.
  10  **/
  11
  12 #ifndef RELAY_CRYPTO_ST_H
  13 #define RELAY_CRYPTO_ST_H
  14
  15 #define crypto_cipher_t aes_cnt_cipher_t
  16 struct crypto_cipher_t;
  17 struct crypto_digest_t;
  18
  19 struct relay_crypto_t {
  20   /* crypto environments */
  21   /** Encryption key and counter for cells heading towards the OR at this
  22    * step. */
  23   struct crypto_cipher_t *f_crypto;
  24   /** Encryption key and counter for cells heading back from the OR at this
  25    * step. */
  26   struct crypto_cipher_t *b_crypto;
  27
  28   /** Digest state for cells heading towards the OR at this step. */
  29   struct crypto_digest_t *f_digest; /* for integrity checking */
  30   /** Digest state for cells heading away from the OR at this step. */
  31   struct crypto_digest_t *b_digest;
  32
  33   /** Digest used for the next SENDME cell if any. */
  34   uint8_t sendme_digest[DIGEST_LEN];
  35 };
  36 #undef crypto_cipher_t
  37
  38 #endif /* !defined(RELAY_CRYPTO_ST_H) */