Diff: include/mbedtls/ssl_ticket.h

Revision:

0:cdf462088d13

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/mbedtls/ssl_ticket.h	Thu Jan 05 00:18:44 2017 +0000
@@ -0,0 +1,135 @@
+/**
+ * \file ssl_ticket.h
+ *
+ * \brief TLS server ticket callbacks implementation
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+#ifndef MBEDTLS_SSL_TICKET_H
+#define MBEDTLS_SSL_TICKET_H
+
+/*
+ * This implementation of the session ticket callbacks includes key
+ * management, rotating the keys periodically in order to preserve forward
+ * secrecy, when MBEDTLS_HAVE_TIME is defined.
+ */
+
+#include "ssl.h"
+#include "cipher.h"
+
+#if defined(MBEDTLS_THREADING_C)
+#include "threading.h"
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief   Information for session ticket protection
+ */
+typedef struct
+{
+    unsigned char name[4];          /*!< random key identifier              */
+    uint32_t generation_time;       /*!< key generation timestamp (seconds) */
+    mbedtls_cipher_context_t ctx;   /*!< context for auth enc/decryption    */
+}
+mbedtls_ssl_ticket_key;
+
+/**
+ * \brief   Context for session ticket handling functions
+ */
+typedef struct
+{
+    mbedtls_ssl_ticket_key keys[2]; /*!< ticket protection keys             */
+    unsigned char active;           /*!< index of the currently active key  */
+
+    uint32_t ticket_lifetime;       /*!< lifetime of tickets in seconds     */
+
+    /** Callback for getting (pseudo-)random numbers                        */
+    int  (*f_rng)(void *, unsigned char *, size_t);
+    void *p_rng;                    /*!< context for the RNG function       */
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_threading_mutex_t mutex;
+#endif
+}
+mbedtls_ssl_ticket_context;
+
+/**
+ * \brief           Initialize a ticket context.
+ *                  (Just make it ready for mbedtls_ssl_ticket_setup()
+ *                  or mbedtls_ssl_ticket_free().)
+ *
+ * \param ctx       Context to be initialized
+ */
+void mbedtls_ssl_ticket_init( mbedtls_ssl_ticket_context *ctx );
+
+/**
+ * \brief           Prepare context to be actually used
+ *
+ * \param ctx       Context to be set up
+ * \param f_rng     RNG callback function
+ * \param p_rng     RNG callback context
+ * \param cipher    AEAD cipher to use for ticket protection.
+ *                  Recommended value: MBEDTLS_CIPHER_AES_256_GCM.
+ * \param lifetime  Tickets lifetime in seconds
+ *                  Recommended value: 86400 (one day).
+ *
+ * \note            It is highly recommended to select a cipher that is at
+ *                  least as strong as the the strongest ciphersuite
+ *                  supported. Usually that means a 256-bit key.
+ *
+ * \note            The lifetime of the keys is twice the lifetime of tickets.
+ *                  It is recommended to pick a reasonnable lifetime so as not
+ *                  to negate the benefits of forward secrecy.
+ *
+ * \return          0 if successful,
+ *                  or a specific MBEDTLS_ERR_XXX error code
+ */
+int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
+    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
+    mbedtls_cipher_type_t cipher,
+    uint32_t lifetime );
+
+/**
+ * \brief           Implementation of the ticket write callback
+ *
+ * \note            See \c mbedlts_ssl_ticket_write_t for description
+ */
+mbedtls_ssl_ticket_write_t mbedtls_ssl_ticket_write;
+
+/**
+ * \brief           Implementation of the ticket parse callback
+ *
+ * \note            See \c mbedlts_ssl_ticket_parse_t for description
+ */
+mbedtls_ssl_ticket_parse_t mbedtls_ssl_ticket_parse;
+
+/**
+ * \brief           Free a context's content and zeroize it.
+ *
+ * \param ctx       Context to be cleaned up
+ */
+void mbedtls_ssl_ticket_free( mbedtls_ssl_ticket_context *ctx );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ssl_ticket.h */