ssl_ticket.h 4.3 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140
  1. /**
  2. * \file ssl_ticket.h
  3. *
  4. * \brief TLS server ticket callbacks implementation
  5. */
  6. /*
  7. * Copyright The Mbed TLS Contributors
  8. * SPDX-License-Identifier: Apache-2.0
  9. *
  10. * Licensed under the Apache License, Version 2.0 (the "License"); you may
  11. * not use this file except in compliance with the License.
  12. * You may obtain a copy of the License at
  13. *
  14. * http://www.apache.org/licenses/LICENSE-2.0
  15. *
  16. * Unless required by applicable law or agreed to in writing, software
  17. * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  18. * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  19. * See the License for the specific language governing permissions and
  20. * limitations under the License.
  21. */
  22. #ifndef MBEDTLS_SSL_TICKET_H
  23. #define MBEDTLS_SSL_TICKET_H
  24. #if !defined(MBEDTLS_CONFIG_FILE)
  25. #include "mbedtls/config.h"
  26. #else
  27. #include MBEDTLS_CONFIG_FILE
  28. #endif
  29. /*
  30. * This implementation of the session ticket callbacks includes key
  31. * management, rotating the keys periodically in order to preserve forward
  32. * secrecy, when MBEDTLS_HAVE_TIME is defined.
  33. */
  34. #include "mbedtls/ssl.h"
  35. #include "mbedtls/cipher.h"
  36. #if defined(MBEDTLS_THREADING_C)
  37. #include "mbedtls/threading.h"
  38. #endif
  39. #ifdef __cplusplus
  40. extern "C" {
  41. #endif
  42. /**
  43. * \brief Information for session ticket protection
  44. */
  45. typedef struct mbedtls_ssl_ticket_key
  46. {
  47. unsigned char name[4]; /*!< random key identifier */
  48. uint32_t generation_time; /*!< key generation timestamp (seconds) */
  49. mbedtls_cipher_context_t ctx; /*!< context for auth enc/decryption */
  50. }
  51. mbedtls_ssl_ticket_key;
  52. /**
  53. * \brief Context for session ticket handling functions
  54. */
  55. typedef struct mbedtls_ssl_ticket_context
  56. {
  57. mbedtls_ssl_ticket_key keys[2]; /*!< ticket protection keys */
  58. unsigned char active; /*!< index of the currently active key */
  59. uint32_t ticket_lifetime; /*!< lifetime of tickets in seconds */
  60. /** Callback for getting (pseudo-)random numbers */
  61. int (*f_rng)(void *, unsigned char *, size_t);
  62. void *p_rng; /*!< context for the RNG function */
  63. #if defined(MBEDTLS_THREADING_C)
  64. mbedtls_threading_mutex_t mutex;
  65. #endif
  66. }
  67. mbedtls_ssl_ticket_context;
  68. /**
  69. * \brief Initialize a ticket context.
  70. * (Just make it ready for mbedtls_ssl_ticket_setup()
  71. * or mbedtls_ssl_ticket_free().)
  72. *
  73. * \param ctx Context to be initialized
  74. */
  75. void mbedtls_ssl_ticket_init( mbedtls_ssl_ticket_context *ctx );
  76. /**
  77. * \brief Prepare context to be actually used
  78. *
  79. * \param ctx Context to be set up
  80. * \param f_rng RNG callback function
  81. * \param p_rng RNG callback context
  82. * \param cipher AEAD cipher to use for ticket protection.
  83. * Recommended value: MBEDTLS_CIPHER_AES_256_GCM.
  84. * \param lifetime Tickets lifetime in seconds
  85. * Recommended value: 86400 (one day).
  86. *
  87. * \note It is highly recommended to select a cipher that is at
  88. * least as strong as the strongest ciphersuite
  89. * supported. Usually that means a 256-bit key.
  90. *
  91. * \note The lifetime of the keys is twice the lifetime of tickets.
  92. * It is recommended to pick a reasonnable lifetime so as not
  93. * to negate the benefits of forward secrecy.
  94. *
  95. * \return 0 if successful,
  96. * or a specific MBEDTLS_ERR_XXX error code
  97. */
  98. int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
  99. int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
  100. mbedtls_cipher_type_t cipher,
  101. uint32_t lifetime );
  102. /**
  103. * \brief Implementation of the ticket write callback
  104. *
  105. * \note See \c mbedtls_ssl_ticket_write_t for description
  106. */
  107. mbedtls_ssl_ticket_write_t mbedtls_ssl_ticket_write;
  108. /**
  109. * \brief Implementation of the ticket parse callback
  110. *
  111. * \note See \c mbedtls_ssl_ticket_parse_t for description
  112. */
  113. mbedtls_ssl_ticket_parse_t mbedtls_ssl_ticket_parse;
  114. /**
  115. * \brief Free a context's content and zeroize it.
  116. *
  117. * \param ctx Context to be cleaned up
  118. */
  119. void mbedtls_ssl_ticket_free( mbedtls_ssl_ticket_context *ctx );
  120. #ifdef __cplusplus
  121. }
  122. #endif
  123. #endif /* ssl_ticket.h */