1 /** 2 * \file ssl_ticket.h 3 * 4 * \brief TLS server ticket callbacks implementation 5 */ 6 /* 7 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 8 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 9 * 10 * This file is provided under the Apache License 2.0, or the 11 * GNU General Public License v2.0 or later. 12 * 13 * ********** 14 * Apache License 2.0: 15 * 16 * Licensed under the Apache License, Version 2.0 (the "License"); you may 17 * not use this file except in compliance with the License. 18 * You may obtain a copy of the License at 19 * 20 * http://www.apache.org/licenses/LICENSE-2.0 21 * 22 * Unless required by applicable law or agreed to in writing, software 23 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 25 * See the License for the specific language governing permissions and 26 * limitations under the License. 27 * 28 * ********** 29 * 30 * ********** 31 * GNU General Public License v2.0 or later: 32 * 33 * This program is free software; you can redistribute it and/or modify 34 * it under the terms of the GNU General Public License as published by 35 * the Free Software Foundation; either version 2 of the License, or 36 * (at your option) any later version. 37 * 38 * This program is distributed in the hope that it will be useful, 39 * but WITHOUT ANY WARRANTY; without even the implied warranty of 40 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 41 * GNU General Public License for more details. 42 * 43 * You should have received a copy of the GNU General Public License along 44 * with this program; if not, write to the Free Software Foundation, Inc., 45 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 46 * 47 * ********** 48 * 49 * This file is part of mbed TLS (https://tls.mbed.org) 50 */ 51 #ifndef MBEDTLS_SSL_TICKET_H 52 #define MBEDTLS_SSL_TICKET_H 53 54 #if !defined(MBEDTLS_CONFIG_FILE) 55 #include "config.h" 56 #else 57 #include MBEDTLS_CONFIG_FILE 58 #endif 59 60 /* 61 * This implementation of the session ticket callbacks includes key 62 * management, rotating the keys periodically in order to preserve forward 63 * secrecy, when MBEDTLS_HAVE_TIME is defined. 64 */ 65 66 #include "ssl.h" 67 #include "cipher.h" 68 69 #if defined(MBEDTLS_THREADING_C) 70 #include "threading.h" 71 #endif 72 73 #ifdef __cplusplus 74 extern "C" { 75 #endif 76 77 /** 78 * \brief Information for session ticket protection 79 */ 80 typedef struct 81 { 82 unsigned char name[4]; /*!< random key identifier */ 83 uint32_t generation_time; /*!< key generation timestamp (seconds) */ 84 mbedtls_cipher_context_t ctx; /*!< context for auth enc/decryption */ 85 } 86 mbedtls_ssl_ticket_key; 87 88 /** 89 * \brief Context for session ticket handling functions 90 */ 91 typedef struct 92 { 93 mbedtls_ssl_ticket_key keys[2]; /*!< ticket protection keys */ 94 unsigned char active; /*!< index of the currently active key */ 95 96 uint32_t ticket_lifetime; /*!< lifetime of tickets in seconds */ 97 98 /** Callback for getting (pseudo-)random numbers */ 99 int (*f_rng)(void *, unsigned char *, size_t); 100 void *p_rng; /*!< context for the RNG function */ 101 102 #if defined(MBEDTLS_THREADING_C) 103 mbedtls_threading_mutex_t mutex; 104 #endif 105 } 106 mbedtls_ssl_ticket_context; 107 108 /** 109 * \brief Initialize a ticket context. 110 * (Just make it ready for mbedtls_ssl_ticket_setup() 111 * or mbedtls_ssl_ticket_free().) 112 * 113 * \param ctx Context to be initialized 114 */ 115 void mbedtls_ssl_ticket_init( mbedtls_ssl_ticket_context *ctx ); 116 117 /** 118 * \brief Prepare context to be actually used 119 * 120 * \param ctx Context to be set up 121 * \param f_rng RNG callback function 122 * \param p_rng RNG callback context 123 * \param cipher AEAD cipher to use for ticket protection. 124 * Recommended value: MBEDTLS_CIPHER_AES_256_GCM. 125 * \param lifetime Tickets lifetime in seconds 126 * Recommended value: 86400 (one day). 127 * 128 * \note It is highly recommended to select a cipher that is at 129 * least as strong as the the strongest ciphersuite 130 * supported. Usually that means a 256-bit key. 131 * 132 * \note The lifetime of the keys is twice the lifetime of tickets. 133 * It is recommended to pick a reasonnable lifetime so as not 134 * to negate the benefits of forward secrecy. 135 * 136 * \return 0 if successful, 137 * or a specific MBEDTLS_ERR_XXX error code 138 */ 139 int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx, 140 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, 141 mbedtls_cipher_type_t cipher, 142 uint32_t lifetime ); 143 144 /** 145 * \brief Implementation of the ticket write callback 146 * 147 * \note See \c mbedtls_ssl_ticket_write_t for description 148 */ 149 mbedtls_ssl_ticket_write_t mbedtls_ssl_ticket_write; 150 151 /** 152 * \brief Implementation of the ticket parse callback 153 * 154 * \note See \c mbedtls_ssl_ticket_parse_t for description 155 */ 156 mbedtls_ssl_ticket_parse_t mbedtls_ssl_ticket_parse; 157 158 /** 159 * \brief Free a context's content and zeroize it. 160 * 161 * \param ctx Context to be cleaned up 162 */ 163 void mbedtls_ssl_ticket_free( mbedtls_ssl_ticket_context *ctx ); 164 165 #ifdef __cplusplus 166 } 167 #endif 168 169 #endif /* ssl_ticket.h */ 170