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Diffstat (limited to 'lib/mbedtls-2.27.0/library/mps_common.h')
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1 files changed, 195 insertions, 0 deletions
diff --git a/lib/mbedtls-2.27.0/library/mps_common.h b/lib/mbedtls-2.27.0/library/mps_common.h new file mode 100644 index 0000000..d20776f --- /dev/null +++ b/lib/mbedtls-2.27.0/library/mps_common.h @@ -0,0 +1,195 @@ +/* + * Copyright The Mbed TLS Contributors + * 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) + */ + +/** + * \file mps_common.h + * + * \brief Common functions and macros used by MPS + */ + +#ifndef MBEDTLS_MPS_COMMON_H +#define MBEDTLS_MPS_COMMON_H + +#include "mps_error.h" + +#include <stdio.h> + +/** + * \name SECTION: MPS Configuration + * + * \{ + */ + +/*! This flag controls whether the MPS-internal components + * (reader, writer, Layer 1-3) perform validation of the + * expected abstract state at the entry of API calls. + * + * Context: All MPS API functions impose assumptions/preconditions on the + * context on which they operate. For example, every structure has a notion of + * state integrity which is established by `xxx_init()` and preserved by any + * calls to the MPS API which satisfy their preconditions and either succeed, + * or fail with an error code which is explicitly documented to not corrupt + * structure integrity (such as WANT_READ and WANT_WRITE); + * apart from `xxx_init()` any function assumes state integrity as a + * precondition (but usually more). If any of the preconditions is violated, + * the function's behavior is entirely undefined. + * In addition to state integrity, all MPS structures have a more refined + * notion of abstract state that the API operates on. For example, all layers + * have a notion of 'abtract read state' which indicates if incoming data has + * been passed to the user, e.g. through mps_l2_read_start() for Layer 2 + * or mps_l3_read() in Layer 3. After such a call, it doesn't make sense to + * call these reading functions again until the incoming data has been + * explicitly 'consumed', e.g. through mps_l2_read_consume() for Layer 2 or + * mps_l3_read_consume() on Layer 3. However, even if it doesn't make sense, + * it's a design choice whether the API should fail gracefully on such + * non-sensical calls or not, and that's what this option is about: + * + * This option determines whether the expected abstract state + * is part of the API preconditions or not: If the option is set, + * then the abstract state is not part of the precondition and is + * thus required to be validated by the implementation. If an unexpected + * abstract state is encountered, the implementation must fail gracefully + * with error #MBEDTLS_ERR_MPS_OPERATION_UNEXPECTED. + * Conversely, if this option is not set, then the expected abstract state + * is included in the preconditions of the respective API calls, and + * an implementation's behaviour is undefined if the abstract state is + * not as expected. + * + * For example: Enabling this makes mps_l2_read_done() fail if + * no incoming record is currently open; disabling this would + * lead to undefined behavior in this case. + * + * Comment this to remove state validation. + */ +#define MBEDTLS_MPS_STATE_VALIDATION + +/*! This flag enables/disables assertions on the internal state of MPS. + * + * Assertions are sanity checks that should never trigger when MPS + * is used within the bounds of its API and preconditions. + * + * Enabling this increases security by limiting the scope of + * potential bugs, but comes at the cost of increased code size. + * + * Note: So far, there is no guiding principle as to what + * expected conditions merit an assertion, and which don't. + * + * Comment this to disable assertions. + */ +#define MBEDTLS_MPS_ENABLE_ASSERTIONS + +/*! This flag controls whether tracing for MPS should be enabled. */ +//#define MBEDTLS_MPS_ENABLE_TRACE + +#if defined(MBEDTLS_MPS_STATE_VALIDATION) + +#define MBEDTLS_MPS_STATE_VALIDATE_RAW( cond, string ) \ + do \ + { \ + if( !(cond) ) \ + { \ + MBEDTLS_MPS_TRACE( MBEDTLS_MPS_TRACE_TYPE_ERROR, string ); \ + MBEDTLS_MPS_TRACE_RETURN( MBEDTLS_ERR_MPS_OPERATION_UNEXPECTED ); \ + } \ + } while( 0 ) + +#else /* MBEDTLS_MPS_STATE_VALIDATION */ + +#define MBEDTLS_MPS_STATE_VALIDATE_RAW( cond, string ) \ + do \ + { \ + ( cond ); \ + } while( 0 ) + +#endif /* MBEDTLS_MPS_STATE_VALIDATION */ + +#if defined(MBEDTLS_MPS_ENABLE_ASSERTIONS) + +#define MBEDTLS_MPS_ASSERT_RAW( cond, string ) \ + do \ + { \ + if( !(cond) ) \ + { \ + MBEDTLS_MPS_TRACE( MBEDTLS_MPS_TRACE_TYPE_ERROR, string ); \ + MBEDTLS_MPS_TRACE_RETURN( MBEDTLS_ERR_MPS_INTERNAL_ERROR ); \ + } \ + } while( 0 ) + +#else /* MBEDTLS_MPS_ENABLE_ASSERTIONS */ + +#define MBEDTLS_MPS_ASSERT_RAW( cond, string ) do {} while( 0 ) + +#endif /* MBEDTLS_MPS_ENABLE_ASSERTIONS */ + + +/* \} name SECTION: MPS Configuration */ + +/** + * \name SECTION: Common types + * + * Various common types used throughout MPS. + * \{ + */ + +/** \brief The type of buffer sizes and offsets used in MPS structures. + * + * This is an unsigned integer type that should be large enough to + * hold the length of any buffer or message processed by MPS. + * + * The reason to pick a value as small as possible here is + * to reduce the size of MPS structures. + * + * \warning Care has to be taken when using a narrower type + * than ::mbedtls_mps_size_t here because of + * potential truncation during conversion. + * + * \warning Handshake messages in TLS may be up to 2^24 ~ 16Mb in size. + * If mbedtls_mps_[opt_]stored_size_t is smaller than that, the + * maximum handshake message is restricted accordingly. + * + * For now, we use the default type of size_t throughout, and the use of + * smaller types or different types for ::mbedtls_mps_size_t and + * ::mbedtls_mps_stored_size_t is not yet supported. + * + */ +typedef size_t mbedtls_mps_stored_size_t; +#define MBEDTLS_MPS_STORED_SIZE_MAX ( (mbedtls_mps_stored_size_t) -1 ) + +/** \brief The type of buffer sizes and offsets used in the MPS API + * and implementation. + * + * This must be at least as wide as ::mbedtls_stored_size_t but + * may be chosen to be strictly larger if more suitable for the + * target architecture. + * + * For example, in a test build for ARM Thumb, using uint_fast16_t + * instead of uint16_t reduced the code size from 1060 Byte to 962 Byte, + * so almost 10%. + */ +typedef size_t mbedtls_mps_size_t; +#define MBEDTLS_MPS_SIZE_MAX ( (mbedtls_mps_size_t) -1 ) + +#if MBEDTLS_MPS_STORED_SIZE_MAX > MBEDTLS_MPS_SIZE_MAX +#error "Misconfiguration of mbedtls_mps_size_t and mbedtls_mps_stored_size_t." +#endif + +/* \} SECTION: Common types */ + + +#endif /* MBEDTLS_MPS_COMMON_H */ |